Rules for the construction and safe operation of steam and hot water boilers. Operation of boiler plants Rules for the safe operation of steam
1. These Rules determine the requirements for the design, manufacture and operation of steam boilers, superheaters and economizers with a working pressure of more than 0.7 kgf / cm2 and hot water boilers with a water temperature above 115 ° C.
2. Boilers subject to these Regulations include:
and) steam boilers with a firebox;
b) waste heat boilers;
in) boilers;
d) hot water boilers with a firebox.
3. The requirements of these Rules do not apply to:
and) boilers and superheaters for steam locomotives and heating boilers for railroad cars;
b) boilers, superheaters and economizers installed on sea and river vessels and other floating equipment;
in) nuclear reactors;
d) boilers with electric heating.
Basic definitions
1. A steam boiler is a device that has a furnace, heated by the products of fuel burned in it and designed to produce steam with a pressure above atmospheric, used outside the device itself.
2. A hot water boiler is a device that has a firebox, heated by the products of the fuel burned in it and designed to heat water under a pressure above atmospheric and used as a heat carrier outside the device itself.
3. Waste heat boiler - steam or hot water, in which hot gases of the technological process are used as a heat source.
4. A boiler-boiler is a steam boiler, in the steam space of which there is a device for heating water used outside the boiler itself, as well as a steam boiler, in the natural circulation of which a free-standing boiler is included.
5. Stationary boiler - installed on a fixed foundation.
6. Mobile boiler - having a chassis or installed on a mobile foundation.
7. Superheater - a device designed to raise the steam temperature above the saturation temperature corresponding to the pressure in the boiler.
8. An economizer is a device heated by fuel combustion products and intended for heating or partial evaporation of water entering a steam boiler. If there is a shut-off device on the pipeline between the boiler and the economizer, the latter is considered to be disconnected by water; in the presence of a bypass gas duct and dampers for disconnecting the economizer from the gas duct, the economizer is considered to be gas disconnected.
Responsibility for Compliance
1. These Rules are binding on all officials, engineers and technicians and workers involved in the design, manufacture, installation, repair and operation of boilers, superheaters and economizers.
2. Officials at enterprises, organizations, as well as engineering and technical workers of design and design institutes and organizations, guilty of violating these Rules, bear personal responsibility regardless of whether this violation led to an accident or an accident. They are also responsible for violations committed by their subordinates.
3. The issuance by officials of instructions or orders forcing their subordinates to violate safety rules and instructions, unauthorized resumption of work stopped by the Gosgortechnadzor bodies or the technical inspection of trade unions, as well as their failure to take measures to eliminate violations of the rules and instructions that are allowed by workers or other subordinate persons in their presence, are gross violations of these Rules. Depending on the nature of the violations and their consequences, all these persons are liable in disciplinary, administrative or judicial procedure.
4. Workers are liable for violations of the requirements of these Rules or special instructions relating to the work they perform in the manner prescribed by the internal labor regulations of enterprises and the criminal codes of the Union republics.
Manufacturing permit, passport and marking
1. Boilers, superheaters, economizers and their elements must be manufactured at enterprises that have permission from the local Gosgortekhnadzor body, in accordance with the "Instruction on the supervision of the manufacture of objects, boiler supervision".
2. The project and technical conditions for the manufacture of boilers, superheaters and economizers must be coordinated and approved in the manner established by the ministry (department), which is subordinate to the design organization, the manufacturer of these objects.
3. Any changes in the project, the need for which may arise during the manufacture, installation, repair or operation of boilers, superheaters and economizers, must be agreed with the organization that carried out the project of these objects, and for boilers, superheaters and economizers purchased abroad, with a specialized organization. on boiler construction.
4. Each boiler, superheater and economizer must be supplied by the manufacturer to the customer with a certificate of the established form and instructions for installation and operation.
5. On the bottoms of the drum or on the boiler body near the water indicating fittings, as well as on the ends or on the cylindrical part of the collectors and chambers of the boiler, superheater and economizer, the following passport data should be stamped: manufacturer or its trademark; serial number of the product; Year of manufacture; design pressure; design wall temperature and steel grade (only on superheater collectors). In addition to the stamps, a metal plate with the above passport data must be attached to the bottom of the drum or the boiler body.
6. Boilers, superheaters, economizers and their elements, as well as materials for the manufacture of this equipment purchased abroad, must meet the requirements and norms of these Rules. Deviations from these Rules must be agreed with the USSR Gosgortekhnadzor prior to purchasing equipment or material abroad.
Fittings, instrumentation and safety devices
General requirements
1. To control the operation and ensure normal operating conditions, boilers, superheaters and economizers must be equipped with fittings, instrumentation and safety devices available for observation and maintenance.
Safety valves
1. Each boiler with a steam capacity of more than 100 kg / h must be equipped with at least two safety valves, one of which must be a control valve. On boilers with a steam capacity of 100 kg / h or less, it is allowed to install one safety valve.
2. The total throughput of the safety valves installed on the boiler must be at least the hourly productivity of the boiler.
3. If the boiler has a non-disconnected superheater, part of the safety valves with a throughput of at least 50% of the total throughput of all valves must be installed on the outlet header of the superheater.
4. On non-disconnectable superheaters of locomotive boilers, steam locomotive type, vertical ones with smoke tubes and other boilers, in which the temperature of the gases washing the superheater, but can cause overheating of its elements, the installation of safety valves is not necessary.
5. It is allowed to use lever-load safety valves or spring (direct action) or pulse (indirect action) safety valves. The auxiliary valve for pulse safety valves must be of direct action with a diameter of at least 15 mm and equipped with an electromagnetic drive.
6. On steam boilers with a pressure higher than 39 kgf / cm2 (with the exception of waste heat boilers and mobile boilers), only pulse safety valves should be installed; on mobile boilers, the installation of lever-cargo valves is not allowed. The diameter of the passage of the lever-cargo and spring valves must be at least 20 mm. It is allowed to reduce the nominal bore of the valves to 15 mm for boilers with a steam capacity of up to 0.2 t / h and a pressure of up to 8 kgf / cm2, provided that two valves are installed.
7. The capacity of the safety valves must be confirmed by appropriate tests of the head sample of the valve of this design, carried out at the valve manufacturer, and is indicated in the valve passport.
8. On steam boilers with an operating pressure of more than 39 kgf / cm2, impulse safety valves (indirect action) must be installed on the outlet manifold of a non-disconnectable superheater or on the steam line to the main shut-off element, while for drum boilers up to 50% of the valves in terms of total throughput steam extraction for pulses must be generated from the boiler drum. On block installations, if valves are located on the steam line directly near the turbines, it is allowed to use superheated steam for pulses of all valves, while for 50% of the valves an additional electrical pulse must be supplied from a contact pressure gauge connected to the boiler drum.
9. In power units with intermediate superheating of steam, after the high-pressure cylinder of the turbine (HPC), safety valves with a throughput capacity of at least the maximum amount of steam entering the intermediate superheater must be installed. If there are shut-off valves behind the HPC, additional safety valves must be installed. These valves are designed for the total throughput of pipelines connecting the reheater system with higher pressure sources that are not protected by their safety valves at the inlet to the reheat system, as well as against possible steam leaks that may occur in case of damage to high pressure steam and gas-steam pipes heat exchangers for steam temperature control.
10. On direct-flow steam boilers, in which the first (along the course of water) part of the heating surface is turned off during firing up or stopping the boiler from the rest of the heating surface by shut-off devices, the need for installation, the number and size of safety valves for the first part are determined by the boiler manufacturer.
11. On hot water boilers, at least two safety valves must be installed, one valve is allowed, when the shut-off devices on the hot water line from the boiler to the expansion vessel have bypasses with pipes with a diameter of at least 50 mm with check valves installed on them for passing water from the boiler to the expansion vessel the vessel is connected to the atmosphere. On direct-flow hot water boilers with chamber combustion of fuel, equipped with an automatic device in accordance with paragraph 4 of these Rules, the installation of safety valves is not required.
12. An economizer that can be switched off by water must be equipped with at least two safety valves with a passage diameter of at least 32 mm each. One valve is installed at the outlet of water from the economizer up to the shut-off element (along the water flow), the other at the inlet to the economizer after the shut-off element (along the water flow). The calculation of the safety valves installed on the economizer should be made according to the formula for calculating safety valves for hot water boilers, given in paragraph 21 of these Rules.
13. Safety valves must be installed on branch pipes connected directly to the boiler drum or to the steam line without intermediate shut-off devices. When several safety valves are located on one branch pipe, the cross-sectional area of \u200b\u200bthe branch pipe must be at least 1.25 of the sum of the cross-sectional areas of all safety valves. The extraction of steam from the branch pipe on which one or more safety valves are located is prohibited. For once-through boilers, the installation of safety valves is allowed in any chute of the steam line up to the shut-off device.
14. The design of safety valves should provide for the possibility of checking their correct operation in working condition by forced opening of the valve. Impulse safety valves must be equipped with a device that allows forced opening of the valve remotely from the place of the boiler operator (stoker). If the force required to open the valves exceeds 60 kgf, the valves must be equipped with appropriate devices for lifting them.
15. Safety valves must have protective devices (branch pipes) that protect the operating personnel from burns when triggered, and the control valves, in addition, must have signaling devices (for example, a whistle) if the exit of the medium from them is not audible from the operator's (stoker's) workplace boiler. The medium leaving the safety valves must be discharged outside the premises; the branch must not create a back pressure behind the valve; discharge pipes must be equipped with a device for draining condensate accumulating in them.
16. The drainage pipe from the economizer safety valves must be connected to the free water drain line, and there must be no shut-off devices either on it or on the drain line; the device of the system of drainage pipes and free drain lines must exclude the possibility of burns to people.
17. Impulse safety valves (indirect action) must have a device that prevents the possibility of shocks when they are opened and closed. Auxiliary valves are not subject to this requirement.
18. Spring valves shall be designed to prevent the spring from being tightened beyond the specified value. The valve springs must be protected from the direct impact of the escaping steam jet.
19. Safety valves must protect boilers and superheaters from exceeding the pressure in them by more than 10% of the design (permitted) pressure. Exceeding the pressure with full opening of the safety valves by more than 10% of the calculated one can be allowed only if the possible pressure increase is taken into account when calculating the strength of the boiler and superheater.
20. The amount of steam that the safety valve can pass when fully opened is determined by the following formulas:
and) for pressure from 0.7 to 120 kgf / cm2; saturated steam
where Gn.p, Gp and G - valve throughput, kg / h; a - coefficient of steam consumption, taken equal to 90% of the value determined when testing head samples of valves of this design, produced by the manufacturer; F is the smallest free cross-sectional area in the flow part of the valve, mm2; P1 - maximum overpressure in front of the safety valve, which should be no more than 1.1 design pressure, kgf / cm2; Vн.п - specific volume of saturated steam in front of the safety valve, m3 / kg; Vp.p - specific volume of superheated steam in front of the safety valve, m3 / kg; V - specific volume of steam (saturated or superheated before the safety valve), m3 / kg.
Formulas (1), (2) and (3) can be applied under conditions for saturated steam if
where P2 is the excess pressure behind the safety valve in the space into which steam flows from the valve (in the case of P2 \u003d 0 outflow into the atmosphere), kgf / cm2.
21. The number and diameter of the passage of safety valves installed on hot water boilers are determined by the formula
where n is the number of safety valves; d is the clear diameter of the valve seat, cm; h - valve lift height, cm; K - empirical coefficient, taken equal to: for low-lift valves (h / d<= 1/20) K=135; для полноподъемных клапанов (h/d >\u003d 1/4) K \u003d 70; Q - maximum heating capacity of the boiler, kcal / h; P is the absolute maximum allowable pressure in the boiler at full opening of the valve, kgf / cm2; i is the heat content of saturated steam at the maximum allowable pressure in the boiler, kcal / kg; tin is the temperature of the water entering the boiler, ° С.
22. Safety valves on steam boilers and superheaters must be adjusted to a pressure not exceeding the values \u200b\u200bgiven in the table.
When adjusting the direct-acting valves installed on the drum, and pulse valves with a pulse from the drum, the pressure in the boiler drum is taken as the operating pressure. When adjusting the direct-acting valves installed on the outlet manifold of the superheater and pulse valves with the selection of pulses downstream of the superheater, the working pressure is taken to be the pressure in the outlet manifold of the superheater (steam line). If the boiler is equipped with two safety valves, then a direct-acting safety valve installed on the outlet manifold of the superheater, or a pulse valve with a pulse take-off downstream of the superheater must be a control one. The check valve shall have a device that prevents the maintenance personnel from adjusting the valve, but does not interfere with checking its condition. On boilers of power trains, in the absence of automatic control of the superheated steam pressure, the safety valve installed after the superheater is considered to be a working valve.
23. The safety valves of the switched off water economizer must be adjusted to the beginning of opening from the side of the water inlet to the economizer at a pressure exceeding the working pressure in the boiler by 25%, and from the side of the water outlet from the economizer by 10% higher. The safety valves of hot water boilers must be adjusted to the beginning of opening at a pressure not exceeding 1.08 of the working pressure in the boiler.
24. The safety valve must be supplied to the customer with a certificate including the characteristic of its capacity.
Water level indicators
1. Each newly manufactured steam boiler for constant monitoring of the position of the water level in the drum must be equipped with at least two water indicating devices of direct action. Water indicating devices can not be installed on direct-flow and other boilers, the design of which does not require monitoring the position of the water level.
2. For boilers with a steam output of less than 0.7 t / h, as well as for locomotive and locomotive boilers, it is allowed to replace one of the water indicating devices with two test taps or valves that allow cleaning them in a forward direction. The installation of the lower tap or valve should be carried out at the level of the lowest, and the upper one - at the level of the highest permissible level of water in the boiler. The inner diameter of the test cock or valve must be at least 8 mm.
3. A direct-acting water indicating device must be designed so that the glass and body can be replaced during the boiler operation.
4. If the distance from the site from which the water level in the steam boiler is monitored to direct-acting water indicating devices is more than 6 m, as well as in cases of poor visibility of the devices, two reliably operating lowered remote water level indicators with calibrated scales must be installed, which must the lowest and highest water levels should be applied according to the water indicating device installed on the same boiler. In this case, it is allowed to install one direct-acting water indicating device on the boiler drums. Reduced or remote water level indicators must be connected to the boiler drum at separate fittings, independently of the upper water indicator devices and have damping devices.
5. On the drums of boilers with staged evaporation, which are used to monitor the water level, at least one water-indicating device should be installed in each clean and each salt compartment, and on the rest of the drums - one water-indicating device in each clean compartment. In the case of a brine compartment with separate separators, the installation of water indicating devices on the separators is not necessary.
6. On boilers with several upper drums connected in series, at least two water-indicating devices must be installed on the drum, along which the water level is constantly monitored, and one water-indicating device on the remaining drums filled with water and steam.
7. If the steam boiler has several upper drums included in parallel circulation systems, i.e. connected by water and steam, at least one water indicating device must be installed on each drum.
8. For steam locomotive boilers, power trains, direct-action level indicators, if there are columns, are installed: one on the column, the other on the front plate of the boiler. In the absence of columns, it is allowed to install one level indicator and three-test taps.
9. Direct-acting water indicating devices should be installed in a vertical plane or with an inclination forward at an angle of no more than 30 ° and should be located and illuminated so that the water level is clearly visible from the operator's (stoker's) workplace.
10. Hot water boilers must have a test tap installed in the upper part of the boiler drum, and in the absence of a drum, at the water outlet from the boiler into the main pipeline up to the shut-off device.
11. On water-indicating devices, a fixed metal indicator with the inscription “Lowest level” must be installed against the permissible lower water level in the boiler. This level should be at least 25 mm above the lower visible edge of the transparent plate (glass). Similarly, the indicator of the highest permissible water level in the boiler must also be installed, which must be at least 25 mm below the upper visible edge of the transparent plate of the water indicator.
12. When installing water-indicating devices, consisting of several separate water-indicating glasses, the latter must be placed so that they continuously indicate the water level in the boiler.
13. Each water indicating device or test tap must be installed on the boiler drum separately from one another. It is allowed to install two water indicating devices on a connecting pipe (column) with a diameter of at least 70 mm. When connecting water indicating devices to the boiler using pipes up to 500 mm long, the inner diameter of these pipes must be at least 25 mm, and if they are longer than 500 mm, their diameter must be at least 50 mm. The pipes connecting the water indicating devices to the boiler must be accessible for internal cleaning. Installation of intermediate flanges and shut-off devices on them is not allowed. The configuration of the pipes connecting the water indicating device to the boiler drum must exclude the possibility of water bags forming in them.
14. The pipes connecting the water indicating devices with the drum (body) of the boiler must be protected from freezing.
15. In direct-operated level indicators for steam boilers, only transparent flat plates (glass) must be used. At the same time, for boilers with a working pressure of up to 39 kgf / cm2, it is allowed to use corrugated glasses and glasses with a smooth surface on both sides. For boilers with a working pressure of more than 39 kgf / cm2, smooth glass with a mica gasket must be used, which protects the glass from the direct effect of water and steam, or a pressure from mica plates. The use of sight plates without their protection with mica is allowed if their material is resistant to the corrosive effects of water and steam on it at the appropriate temperature and pressure.
16. Water indicating devices must be equipped with shutoff valves (valves or gate valves) to disconnect them from the boiler and purge valves. To drain the water when blowing water indicating devices, there must be funnels with a protective device and a drain pipe for free drainage. At a pressure of more than 45 kgf / cm2, two shut-off devices must be installed on the water indicating devices to disconnect from the boiler. The use of plug valves as shutoff bodies is allowed in this case only for boilers with operating pressures up to 13 kgf / cm2.
Pressure gauges
1. Each steam boiler must be fitted with a pressure gauge showing the steam pressure. On boilers with a steam capacity of more than 10 t / h and hot water boilers with a heating capacity of more than 5 Gcal / h, the installation of a recording pressure gauge is mandatory. The pressure gauge must be installed on the boiler drum, and if the boiler has a superheater - and behind the superheater, up to the main valve. On direct-flow boilers, the pressure gauge should be installed behind the superheater in front of the shut-off element. The installation of a manometer on steam superheaters of locomotive, locomobile, fire tube and vertical type boilers is not necessary.
2. Each steam boiler must have a pressure gauge installed on the feed line in front of the body that regulates the boiler's water supply. If several boilers with a steam capacity of less than 2 t / h each are installed in the boiler room, it is allowed to install one pressure gauge on a common feed line.
3. When using a water supply network, a pressure gauge should be installed on this water supply network instead of the second feed pump in the immediate vicinity of the boiler.
4. On a water-disconnected economizer, pressure gauges should be installed at the water inlet up to the shut-off element and safety valve and at the water outlet up to the shut-off element and safety valve. If there are pressure gauges on common feed lines to economizers, their installation at the water inlet to each economizer is not necessary.
5. Pressure gauges are installed on hot water boilers: at the water inlet to the boiler and at the outlet of heated water from the boiler to the shut-off element, at the suction and discharge lines of the circulation pumps with the same height, as well as at the boiler power lines or the heating network recharge lines.
6. Pressure gauges installed on boilers, superheaters, economizers and feed lines must have an accuracy class of at least:
2.5 - for working pressure up to 23 kgf / cm2;
1.6 - for working pressure over 23, up to 140 kgf / cm2 inclusive;
1.0 - for working pressure over 140 kgf / cm2.
7. The pressure gauge should be with such a scale that, at operating pressure, its pointer is in the middle third of the scale.
8. On the scale of the pressure gauge, a red line should be marked with a division corresponding to the highest permissible operating pressure in the boiler, and for reduced pressure gauges - taking into account the additional pressure from the weight (mass) of the liquid column. Instead of the red line, it is allowed to attach a red-colored metal plate to the pressure gauge body that fits tightly to the pressure gauge glass.
9. The pressure gauge should be installed so that its readings are clearly visible to the maintenance personnel, while its scale should be in a vertical plane or with an inclination forward to 30 ° C. The nominal diameter of pressure gauges installed at a height of up to 2 m from the level of the observation platform of the pressure gauge must be at least 100 mm, at a height of 2 to 5 m - at least 150 mm, and at a height of more than 5 m - at least 250 mm.
10. Between the pressure gauge and the steam boiler, there must be a connecting siphon pipe with a diameter of at least 10 mm with a three-way cock or other similar device with a hydraulic seal. On boilers with a pressure higher than 39 kgf / cm2, with the exception of power train boilers, instead of a three-way valve, valves should be installed on the siphon tube to disconnect the pressure gauge from the boiler, communicate it with the atmosphere and blow out the siphon tubes.
11. Pressure gauges are not allowed for use in cases where:
and) there is no seal or stamp on the pressure gauge with a mark on the inspection;
b) pressure gauge verification period has expired;
in) the arrow of the manometer, when it is turned off, does not return to the zero reading of the scale by an amount exceeding half of the permissible error for this manometer;
d) glass is broken or there are other damages to the pressure gauge, which may affect the accuracy of its readings.
Instruments for measuring the temperature of steam, water and liquid fuels
1. On steam lines of superheated steam in the area from the boiler to the main steam valve, instruments must be installed to measure the temperature of superheated steam. For boilers with natural circulation with a steam capacity of over 20 t / h, and for direct-flow boilers with a steam capacity of more than 1 t / h, in addition, it is mandatory to install a device that records the steam temperature.
2. On superheaters with several parallel sections, in addition to devices for measuring the temperature of steam installed on common steam pipelines of superheated steam, devices must be installed for periodically measuring the temperature of the steam at the outlet of each section, and for boilers with a steam temperature above 500 ° C - at the output part superheater coils, one thermocouple (sensor) per meter of duct width. For boilers with a steam capacity of more than 400 t / h, instruments for measuring the temperature of steam at the output of the coils of superheaters must be continuous with a recording device.
3. In the presence of an intermediate superheater, devices for measuring the temperature of steam in accordance with Art. 2.
4. If there is a desuperheater on the boiler to control the temperature of the superheat of the steam upstream and downstream of the desuperheater, instruments for measuring the temperature of the steam must be installed.
5. At the water inlet and outlet of the economizer, as well as at the feed lines of steam boilers without an economizer, sleeves must be installed to measure the temperature of the feed water.
6. In hot water boilers, water temperature measuring devices must be installed at the water inlet and outlet of the boiler. At the hot water outlet, the appliance must be positioned between the boiler and the shut-off element. For a boiler with a heat output of more than 1 Gcal / h, the temperature measuring device installed at the water outlet from the boiler must be recording.
7. When operating liquid fuel boilers, a thermometer must be installed in the fuel line in the immediate vicinity of the boiler to measure the temperature of the fuel in front of the nozzles.
Fittings of the boiler and its pipelines
1. Fittings installed on the boiler or pipelines must be clearly marked, which must indicate:
a) the name or trademark of the manufacturer; b) conditional pass; c) nominal pressure or operating pressure and temperature of the medium; d) the direction of the flow of the medium.
2. Valves with a nominal bore of over 20 mm made of alloy steel must have a passport (certificate), which indicates the grades of materials used for the manufacture of the main parts (body, cover, fasteners), nominal bore, nominal pressure or working pressure and temperature Wednesday.
3. Signs on the flywheel of the valve must indicate the direction of rotation when opening and closing the valve.
4. On all pipelines of boilers, superheaters and economizers, the fittings must be connected on flanges or by welding. In boilers with a steam capacity of not more than 1 t / h, fittings can be connected to the thread with a nominal bore of no more than 25 mm and a saturated steam working pressure of no higher than 8 kgf / cm2.
5. A shut-off valve or gate valve must be installed between the boiler and the steam line or turbine connected to it. If there is a superheater, stop valves must be installed behind the superheater. If necessary, a check valve can be installed between the shutoff valves and the boiler, which prevents the entry of steam into the boiler from the common steam pipeline of the boiler room. On steam pipelines of mobile steam generators (PPU), the installation of a check valve is required. In boilers with a pressure of more than 39 kgf / cm2, at least two shut-off bodies with a drainage device between them with a passage of at least 20 mm in communication with the atmosphere must be installed on each steam line from the boiler to the boiler’s common steam line or to the turbine stop valve. On steam pipelines of monoblocks (boiler-turbine), shut-off valves behind the boiler can be omitted, provided that the need for it is not due to the scheme of kindling, stopping or adjusting the operation of the boiler.
6. If there is an intermediate superheater in the boiler, one shut-off valve should be installed at the steam inlet and outlet from it. In monoblocks, the installation of valves is not required. If steam is sent from the turbine to the reheaters of two or more boilers, then at the inlet to the reheater of each boiler, in addition to the shut-off valve, a regulating body must be installed for proportional distribution of steam over the superheaters of individual boilers.
7. Shut-off devices on steam lines should be located as close as possible to the boiler (superheater). For direct-flow boilers, as well as for monoblocks and double-blocks (two turbine boilers) with drum boilers, shutoff valves can be installed anywhere in the steam line connecting the boiler to the common steam line of the boiler room or with the turbine stop valve.
8. For each boiler with a steam capacity of 4 t / h or more, the control of the main steam shut-off device should be carried out from the workplace of the boiler driver (stoker).
9. A shut-off valve or gate valve and a non-return valve must be installed on the supply line to prevent water from leaving the boiler into the supply line. On boilers with pressures up to 39 kgf / cm2, a shut-off element is installed between the boiler and the non-return valve. For steam boilers with centralized power supply, when using flangeless fittings, at least two shut-off valves or gate valves must be installed on each feed pipeline, between which there must be a drainage device with a passage of at least 20 mm, connected to the atmosphere. If the boiler has an economizer that cannot be switched off by water, then a shut-off element and a non-return valve are installed on the supply pipelines in front of the economizer. For an economizer that is shut off by water, a shut-off element and a check valve must also be installed at the outlet of the water from the economizer.
10. Control fittings (valves, valves) must be installed on the feed lines of each steam boiler. With automatic regulation of the boiler supply, there must be a remote drive to control the control feed valves from the workplace of the boiler operator (stoker).
11. When installing several feed pumps having common suction and discharge pipelines, shut-off elements must be installed on each suction and discharge sides of each pump. A non-return valve must be installed on the discharge port of each centrifugal pump up to the shut-off element.
12. A safety valve must be installed on the supply line between the piston pump (which does not have a safety valve) and the shut-off element, so that the design pressure of the supply line cannot be exceeded. The internal diameter of the connected pipeline (pipe) to the safety valve must be at least 1/3 of the internal diameter of the feed pipe and at least 25 mm.
13. The feed pipe must have air vents to release air from the upper points of the pipeline and drainage to drain water from the lower points of the pipeline.
14. Each boiler (superheater, economizer) must have pipelines for:
a) purging the boiler and draining the water when the boiler is stopped; b) removal of air from the boiler during kindling; c) removing condensate from steam pipelines; d) sampling water and steam and adding additives to boiler water; e) release of superheated steam from drum boilers and water or steam from once-through boilers when firing up or stopping.
For boilers with a capacity of not more than 1 t / h, the installation of pipelines specified in paragraphs "b" and "d" is not required.
15. The system of purge and drain pipelines should provide the ability to remove water and sediment from the lowest parts of the boiler (superheater, economizer). The nominal passage of the drain pipelines must be at least 50 mm. For water-tube boilers without lower drums, the nominal bore of the drain pipelines connected to the lower chambers must be at least 20 mm. For boilers with pressures above 60 kgf / cm2, it is necessary to install two shut-off devices on each drain pipe. Shut-off devices should be installed as close to the drum or chamber as possible. On the section of the pipeline between the boiler and the shut-off element, there should be no detachable connections, except for flanged ones, necessary for connecting this pipeline with the boiler or shut-off element.
16. On boilers with a pressure of 39 kg / cm2 and more, there must be devices controlled from the workplace of the boiler driver to discharge water from the upper drum in the event of a dangerous overflow of it above the upper permissible level. This device must exclude the possibility of draining water below the lowest permissible level.
17. The purge lines must be connected at the lowest points of the respective drums, chambers and boiler casings. For boilers with a pressure of more than 8 kgf / cm2, two shut-off elements or one shut-off and one regulating device must be installed on each purge line. In boilers with a pressure of more than 100 kgf / cm2 in these pipelines, in addition, the installation of throttle washers is allowed. For purging the chambers of the superheaters, it is allowed to install one shut-off device. The nominal passage of the purge pipelines and fittings installed on them must be at least 20 mm for boilers with a pressure of up to 140 kgf / cm2 and at least 10 mm for boilers with a pressure of 140 kgf / cm2 and more.
18. Each boiler for intermittent blowdown shall have an independent blowdown line connected to a common line directed to the atmosphere or to a blowdown tank operating without pressure. The use of a pressure purge tank is permitted, provided the tank is equipped with at least two safety valves. Devices for continuous boiler blowdown and blowdown of steam collectors (chambers) must have separate blowdown lines. The installation of shut-off valves on common purge or drain lines is prohibited. It is allowed to install an additional locking element on a common drain or purge line, combining several drain or purge lines of one boiler. The device of the purge and drain lines must exclude the possibility of burns to people.
19. On drain and purge pipelines, the use of cast iron fittings (with the exception of ductile iron fittings), fittings, as well as cork racks, gas welded and cast iron pipes is not allowed.
20. In places of possible accumulation of air in the boiler and economizer, devices must be installed to remove it. If it is possible to remove the air accumulating in the economizer through the drain pipes, then the installation of an air removal device is not necessary. A venting device must not be installed on the steam extraction pipe.
21. In all sections of the steam pipeline, which can be shut off by the locking elements, drainages must be arranged to ensure the drainage of condensate. A shut-off element must be installed on each drainage pipeline, and at a pressure of more than 8 kgf / cm2 - two shut-off bodies or one shut-off valve and one control valve. For boilers with a pressure of more than 100 kgf / cm2, in addition to shut-off devices, it is allowed to install throttling washers.
22. Each hot water boiler connected to a common hot water main must have one shut-off element (valve or gate valve) installed on the inlet and outlet pipelines.
23. A hot water boiler in the upper part of the drum must have a device to remove air when filling the boiler (system) with water.
24. On hot water boilers with forced circulation, in order to prevent a sharp increase in pressure and temperature of water in the boiler in the event of an accidental stop of circulation pumps, a drain device with an internal diameter of at least 50 mm with a shut-off valve must be installed on the pipeline or collector of hot water from the boiler to the stop valves ( valve) to drain water into the drain. On boilers with a capacity of 4 Gcal / h or more, the installation of a drain device is not required.
Safety devices
1. Boilers with a steam capacity of 0.7 t / h and above with chamber combustion of fuel must be equipped with devices that automatically cut off the fuel supply to the burners when the water level drops below the permissible limit.
2. Steam and hot water boilers operating on gaseous fuel, when air is supplied to the burners from blowing fans, must be equipped with devices that automatically cut off the gas supply to the burners when the air pressure drops below the allowable value.
3. Water circulation boilers with multiple circulation and chamber combustion of fuel must be equipped with devices that automatically stop the fuel supply to the burners, and with layer-by-layer combustion of fuel - devices that turn off the blower devices when the water pressure in the system is reduced to a value that creates the risk of hydraulic shock, and at rising water temperature above the set.
4. Direct-flow hot water boilers with chamber combustion of fuel must be equipped with automatic devices that stop the supply of fuel to the furnace of the boiler, and in case of layer-by-layer burning of fuel, they shut off the draft devices and fuel supply mechanisms of the furnace in the following cases:
a) increasing the water pressure in the boiler outlet header to 1.05 of the design pressure for the strength of the heating system pipeline and the boiler itself: b) lowering the water pressure in the boiler outlet header to a value corresponding to the saturation pressure at the maximum operating temperature of the water leaving the boiler; c) increasing the water temperature at the outlet of the boiler to a value of 20 ° C below the saturation temperature corresponding to the working water pressure in the outlet header of the boiler; d) reducing the flow rate of water through the boiler, in which underheating of water to a boil at the outlet of the boiler at maximum load and operating pressure in the outlet manifold reaches 20 ° C.
The determination of this flow rate should be determined by the formula
where Gmin is the minimum allowable water flow through the boiler, kg / h; Qmax - maximum boiler heat output, kcal / h; ts is the boiling point of water at a working pressure at the outlet of the boiler, ° C; tin - water temperature at the inlet to the boiler, ° С.
In order to avoid water boiling, its average speed in individual pipes heated by radiation from the firebox must be at least 1 m / s.
5. On boilers with a steam capacity of 0.7 t / h and higher, automatically operating sound alarms of the upper and lower limit positions of water levels must be installed.
6. Boilers with a steam capacity of 2 t / h and more should be equipped with automatic power regulators; This requirement does not apply to boiler boilers for which the selection of steam to the side, in addition to the boiler, does not exceed 2 t / h.
7. Boilers with a superheat temperature above 400 ° C must be equipped with automatic temperature control for superheated steam. In cases where it is possible to increase the temperature of the walls of the pipes of the intermediate superheater in excess of the permissible value, it should be equipped with a protective device to prevent such an increase in the temperature of the steam.
8. Safety devices must be protected from exposure to persons not associated with their maintenance and repair, and have devices for checking the serviceability of their operation.
Water mode of boilers
General requirements
1. The choice of the method of water treatment for powering boilers should be made by a specialized (design, commissioning) organization.
2. The water regime must ensure the operation of the boiler and the feed path without damaging their elements due to scale deposits and sludge, excess relative alkalinity of the boiler water to dangerous limits or as a result of metal corrosion, and also ensure the production of steam of the proper quality. All boilers with steam output of 0.7 t / h and more should be equipped with pre-boiler water treatment plants. It is also allowed to use other effective methods of water treatment, which guarantee the fulfillment of the requirements of this article.
3. For boilers with a steam capacity of 0.7 t / h and more, taking into account their design, a specialized (commissioning) organization should develop an instruction (regime chart) approved by the administration of the enterprise, indicating the procedure for performing analyzes of boiler and feed water, quality standards for feed and boiler water, the mode of continuous and periodic blowdowns, the procedure for servicing equipment at water treatment, the timing of stopping the boiler for cleaning and flushing, and the procedure for inspecting the stopped boilers. If necessary, a check of the boiler water aggressiveness should be provided.
4. The boiler room should have a water treatment log (sheet) for recording the results of water analyzes, performing the boiler blowdown mode and operations for servicing water treatment equipment. At each stopping of the boiler to clean the internal surfaces of its elements, the type and thickness of scale and sludge, the presence of corrosion, as well as signs of leaks (soaring, external salt build-up) in riveted and rolling joints must be recorded in the water treatment log.
5. For boilers with a steam capacity of less than 0.7 t / h, the period between cleanings should be such that the thickness of deposits in the most heat-stressed areas of the boiler heating surface by the time it stops for cleaning does not exceed 0.5 mm.
6. On reserve lines of raw water connected to the lines of softened feed water or condensate, as well as to the feed tanks, two shut-off bodies and a control valve between them must be installed. The locking elements must be in the closed position and be sealed, the control valve is open. Each feed of raw water should be recorded in the water treatment log.
Feed water requirements
1. The quality of feed water for boilers with natural circulation with a steam capacity of 0.7 t / h and higher with a working pressure of up to 39 kgf / cm2 must comply with the following standards:
and) total hardness (no more):
for gas-tube and fire-tube boilers operating on solid fuel - 500 μg-eq / kg;
for gas-tube and fire-tube boilers operating on gaseous or liquid fuel - 30 μg-eq / kg;
for water-tube boilers with a working pressure of up to 13 kgf / cm2 - 20 μg-eq / kg;
for water-tube boilers with a working pressure above 13 to 39 kgf / cm2 - 15 μg-eq / kg;
b) the content of dissolved oxygen (no more): for boilers with an operating pressure of up to 39 kgf / cm2 and a steam capacity of 2 t / h or more, without economizers, and for boilers with cast iron economizers - 100 μg / kg; for boilers with an operating pressure of up to 39 kgf / cm2 and a steam capacity of 2 t / h or more with steel economizers - 30 μg / kg;
in) oil content (no more):
for boilers with a working pressure of up to 13 kgf / cm2 - 5 mg / kg;
for boilers with a working pressure above 13 kgf / cm2 up to 39 kgf / cm2 - 3 mg / kg.
2. The quality of feed water for steam boilers with natural circulation with an operating pressure of more than 39 kgf / cm2, as well as for once-through boilers, regardless of pressure, must meet the requirements of the Rules for the Technical Operation of Power Plants and Networks.
3. The standards for salinity and alkalinity of boiler water are established on the basis of appropriate tests. The relative alkalinity of the boiler water for steam boilers must not exceed 20%. In steam boilers with welded drums, an increase in the relative alkalinity of boiler water in excess of the permissible norm may be allowed, provided that measures are taken to prevent intergranular corrosion of the metal.
4. The quality of make-up water for boilers must comply with the following standards:
a) carbonate hardness - not more than 700 mcg-equiv / kg; b) the content of dissolved oxygen is not more than 50 μg / kg; c) content of suspended solids - no more than 5 mg / kg; d) the content of free carbon dioxide is not allowed; d) a pH of not less than 7.
Nutritional devices
General requirements
1. The following nutrient devices are allowed to power the boiler with water;
and) centrifugal and piston pumps with electric drive;
b) piston and centrifugal pumps with steam drive; c) steam injectors; d) pumps with manual drive.
2. A plate must be affixed to the housing of each feed pump and injector with the following details:
a) name of the manufacturer; b) year of manufacture and serial number; c) nominal flow at a nominal water temperature in m3 / h (l / min); d) the number of revolutions per minute for centrifugal pumps or the number of strokes per minute for piston pumps; e) maximum head at nominal flow, m of water. Art. (kgf / cm2); f) nominal water temperature in front of the pump, ° С.
In the absence of a factory certificate, a pump test should be carried out to determine its flow and head. This test should be carried out after each pump overhaul.
3. The pump head must be selected taking into account the supply of water to the boiler at a pressure corresponding to the full opening of the operating safety valves installed on the steam boiler, as well as taking into account the pressure loss in the discharge network.
4. To supply boilers with a working pressure of not more than 4 kgf / cm2 and a steam capacity of not more than 1 t / h, the use of a water supply system as a backup power source is allowed if the water pressure in the latter directly at the boiler exceeds the permitted pressure in the boiler by at least 1.5 kgf / cm2.
5. For boilers with a working pressure of not more than 4 kgf / cm2 and a steam capacity of not more than 150 kg / h with periodic feeding, manual feed pumps are allowed.
6. Steam boilers with different operating pressures must be powered from independent feed devices. It is allowed to supply such boilers from one feed device if the difference in operating pressures of the boilers does not exceed 15%. Feed pumps connected to a common line must have characteristics that allow parallel operation of the pumps.
7. Instead of pumps with a steam drive, it is allowed to use injectors in the same number and the same capacity as feeding devices.
8. In block installations (boiler-turbine or two boilers-turbines), the power supply to the boilers must be individual for each block.
9. Each once-through boiler must have an independent feeding device (with electric or steam drive), independent of the feeding devices of boilers of other designs.
10. When using feed pumps only with a steam drive, there must be an additional feed device to power the steam boiler during firing up or supply steam to the steam drive from the side.
11. When using pumps only with an electric drive, automatic switching from one independent power source to another should be provided.
Number and performance of nutrient devices
1. The number and supply of electrically driven pumps for powering steam boilers of stationary power plants are selected so that in the event of a stop of any of the pumps, the remaining ones will ensure the operation of all working boilers (without a backup boiler) at their nominal steam capacity, taking into account the water consumption for blowdown and other losses. In addition to these feed pumps, steam powered backup feed pumps must be installed:
and) at power plants that are not included in the general power system or are not connected by parallel operation with another permanently operating power plant; b) for powering steam boilers with chamber combustion of fuel, in which drums are heated with hot gases; c) for supplying steam boilers with layered fuel combustion.
The total supply of reserve feed pumps must ensure at least 50% of the rated steam capacity of all working boilers. The use of pumps with a steam drive is allowed as the main permanently operating feeding devices, while the installation of backup pumps is not necessary. The number and supply of pumps for supplying direct-flow boilers with a steam capacity of 450 t / h and more for supercritical parameters are selected so that in the event of a stop of the most powerful pump, the remaining ones, including the reserve pump, will ensure the operation of the boiler with a steam capacity of at least 50% of the nominal.
2. To supply steam boilers (with the exception of boilers for power plants and power trains), at least two independently driven feed pumps must be installed, of which one or more must be steam-driven. The total flow of pumps with an electric drive must be at least 110%, and with a steam drive - at least 50% of the rated steam capacity of all operating boilers. It is allowed to install all feed pumps only with a steam drive, and in the presence of two or more independent power supplies, only with an electric drive. Pumps for steam boilers with a pressure of not more than 4 kgf / cm2 can only be electrically driven with one power source. In these cases, the number and flow of pumps are selected so that when the most powerful pump stops, the total flow of the remaining pumps is at least 110% of the rated steam capacity of all working boilers. Boilers with steam capacity not exceeding 1 t / h with one feed pump with electric drive are allowed if the boilers are equipped with an automatic safety device that excludes the possibility of lowering the water level and raising the pressure above the permissible level.
3. To supply boiler-boilers in the absence of steam extraction, in addition to the boiler, at least two pumps with a total supply of at least 50% of the steam capacity of the most powerful boiler must be installed. If there is steam extraction, in addition to the boiler, the total pump delivery must be increased taking into account the actual steam extraction.
4. For feeding boilers with natural circulation, at least two pumps must be installed, and for boilers with forced circulation there must be at least two pumps for feeding and at least two circulation pumps. The pressure and flow rate of the pumps must be selected in such a way that if the most powerful pump fails, the remaining ones can ensure the normal operation of the boilers (system). Pumps for a hot water boiler with a heating capacity of 4 Gcal / h and more must have two independent power sources for the electric drive. To feed hot water boilers instead of one of the total number of pumps, it is allowed to use a water supply system if the pressure in the water supply system directly at the point of its connection to the boiler or system exceeds the sum of the static and dynamic pressure of the system by at least 1.5 kgf / cm2.
5. The pressure generated by the circulation and make-up pumps must exclude the possibility of water boiling in the boiler and system.
6. The number and supply of feed pumps for supplying steam trains for energy trains must comply with the following standards:
and) with individual power supply, each boiler has one working pump with steam or electric drive and one standby pump with steam drive. The flow rate of each pump must be at least 120% of the rated steam capacity of the boiler;
b) in case of centralized power supply of boilers, two pumps with a steam or electric drive must be installed, each supplying at least 120% of the total nominal steam capacity of all working boilers. In addition, each boiler must have one backup steam pump with a supply of at least 120% of the nominal steam capacity of this boiler.
7. When feeding devices are located outside the boiler room, a direct telephone or other connection should be established between the driver (fireman) and the personnel serving the feeding devices.
8. The supply line must be rated for the maximum pressure generated by the pumps connected to it. Boilers with a steam capacity of 4 t / h and more with a layered method of burning fuel, and with any other method of burning fuel in the presence of drums heated by hot gases, should be fed through two independent supply pipelines. One feed line between the power regulator and the boiler is allowed. The throughput of each feed and suction pipe must ensure the rated steam capacity of the boiler, taking into account the water consumption for blowdown.
Boiler rooms
General requirements
1. Stationary boilers must be installed in separate buildings (closed boiler rooms). Installation of boilers in boiler rooms is allowed:
a) semi-open type - in areas with a calculated outdoor temperature below minus 20 ° C to minus 30 ° C; b) open type - in areas with a design temperature of the outside air from minus 20 ° C and above.
In areas of dust storms and heavy precipitation, regardless of the calculated outside temperature, the boilers should be placed in closed boiler rooms. Heat recovery boilers and steel straight-through hot-water boilers of a tower type can be installed in open-type boiler houses in areas with a calculated outdoor temperature of at least minus 35 ° С. When placing boilers in semi-open and open boiler rooms, measures must be taken against the effects of atmospheric precipitation on the lining of boilers, freezing of water in pipelines, valves and boiler elements during their operation and shutdown. All measuring instruments, devices for regulating and controlling the operation of boilers, feeding devices, water treatment equipment (with the exception of deaerators) and workplaces of service personnel must be located in warm rooms. Boilers must be protected from access by unauthorized persons.
Note. The design temperature of the outside air is the average air temperature of the coldest five-day period of the year in the area where the boiler house is located.
2. Boiler rooms should not be adjacent to residential buildings and public premises (theaters, clubs, hospitals, children's institutions, educational institutions, locker rooms and soap rooms of baths, shops), as well as be located inside these buildings. It is allowed to adjoin boiler rooms to production premises, provided that they are separated by a fire wall with a fire resistance limit of at least 4 hours. If there are doorways in this wall, the doors should open towards the boiler room. The construction of any premises directly above the boilers is not allowed.
3. Inside industrial premises, as well as above and below them, it is allowed to install:
a) once-through boilers with a steam capacity of no more than 4 t / h each; b) boilers satisfying the condition (t - 100) V<= 100 (для каждого котла), где t - температура насыщенного пара при рабочем давлении, °С; V - водяной объем котла, м3; в) водогрейных котлов теплопроизводительностью каждый не более 2,5 Гкал/ч, не имеющих барабанов; г) котлов-утилизаторов без ограничений.
4. The installation site of the boilers inside the production premises, above and below them, should be separated from the rest of the room by fireproof partitions along the entire height of the boiler, but not lower than 2 m, with the door installed for access to the boiler. Recovery boilers can be separated from the rest of the production room together with furnaces or units with which they are connected by a technological process.
5. In industrial premises adjacent to residential premises, but separated from them by capital walls, it is allowed to install steam boilers, in which (t - 100) V<= 5, где t - температура жидкости при рабочем давлении, °С; V - водяной объем котла, м3.
6. In the buildings of the boiler room, it is allowed to place household, office premises and workshops designed to repair the equipment of the boiler room, provided that they are separated by walls and ceilings made of non-combustible materials, and normal conditions are provided for people working in them.
7. If it is necessary to install an ash room in the boiler room, it must be isolated from other rooms to prevent the penetration of gas and dust into them.
8. It is allowed to use the boiler frame as load-bearing elements of the building structure, if this is provided by the project.
9. For service personnel in the building of the boiler room, household premises must be equipped in accordance with sanitary standards.
10. All elements of boilers, pipelines, superheaters, economizers and auxiliary equipment with an outer surface wall temperature above 45 ° C, located in places accessible to service personnel, must be covered with thermal insulation, the outer surface temperature of which should not exceed 45 ° C.
11. The ventilation and heating of the boiler room must ensure the removal of excess moisture, harmful gases and dust and maintain the following temperature conditions:
a) in the area of \u200b\u200bpermanent residence of the service personnel, the air temperature in winter should not be lower than 12 ° C, and in summer it should not exceed the outside air temperature by more than 5 °; b) in the remaining places of the possible stay of the service personnel, the air temperature should not exceed by more than 15 ° C the temperature in the main zone.
12. In the boiler room attic floors above boilers are not allowed.
13. The floor level of the lower floor of the boiler room should not be lower than the level of the territory adjacent to the boiler building.
Arrangement of doors and vestibules
1. Each floor of the boiler room must have at least two exits located on opposite sides of the room. A single exit is allowed if the floor area is less than 200 m2 and there is an emergency exit to the external fire escape, and in single-storey boiler rooms - when the length of the room along the front of the boilers is not more than 12 m. Both direct exit to the outside and exit through the boiler room are considered stairwell or vestibule.
2. Exit doors from the boiler room must open outward from pressure by hand and must not have locks from the boiler room. All exit doors of the boiler room must not be locked during operation of the boilers. Exit doors from the boiler room to the service, household, as well as auxiliary production rooms should be supplied with springs and open towards the boiler room.
3. The gates of the boiler room, through which fuel is supplied and ash and slag are removed, must have a vestibule or an air heat curtain. The dimensions of the vestibule should ensure safety and ease of maintenance for the supply of fuel or the removal of ash and slag. In areas with an average air temperature of the coldest five-day run not lower than minus 5 ° C, the device of vestibules and heat curtains is not necessary.
Lighting
1. The boiler room must be provided with sufficient daylight, and at night - with electric lighting. Places that, for technical reasons, cannot be provided with daylight must have electric lighting. Illumination of the main workplaces should not be lower than the following standards:
2. In addition to working lighting, boiler rooms should have emergency electric lighting from power sources that are independent of the general electric lighting network of the boiler room. The following places are subject to mandatory emergency lighting equipment:
a) the front of the boilers, as well as the passages between the boilers, behind the boilers and above the boilers; b) heat shields and control panels; c) water indicating and measuring devices; d) ash facilities; e) fan area; e) smoke exhaust platform; g) rooms for tanks and deaerators; h) platforms and ladders of boilers; i) pumping room.
For boiler rooms with a floor area of \u200b\u200bup to 250 m2, portable electric lights are allowed as emergency lighting.
3. Electrical equipment, lamps, conductor, grounding and their installation must comply with the requirements of the Electrical Installation Rules.
4. For electric lamps of general and local lighting, suspended at a height below 2.5 m above the floor or platforms, the voltage should be no more than 36 V. A voltage of 127-220 V is allowed, provided that the lighting device does not allow people to replace lamps on which this is not assigned by the instructions for the boiler room personnel, and the lamps will be protected from accidental touching by the operating personnel.
Placement of boilers and auxiliary equipment
1. The distance from the front of the boilers or protruding parts of the furnaces to the opposite wall of the boiler room should be at least 3 m, while for boilers operating on gaseous or liquid fuel, the distance from the protruding parts of the burners to the wall of the boiler room should be at least 1 m, and for for boilers equipped with mechanized furnaces, the distance from the protruding parts of the furnaces must be at least 2 m.For boilers with a steam capacity of no more than 2 t / h, the distance from the front of the boilers or protruding parts of the furnaces to the boiler room wall can be reduced to 2 m in the following cases:
a) if the manual solid fuel furnace is operated from the front and has a length of not more than 1 m; b) if there is no need to service the furnace from the front; c) if the boilers are heated by gaseous or liquid fuel (while maintaining the distance from the burner devices to the boiler wall at least 1 m).
2. The distance between the front of the boilers and the protruding parts of the furnaces located opposite each other should be:
a) for boilers equipped with mechanized furnaces - at least 4 m; b) for boilers operating on gaseous and liquid fuels - at least 4 m, while the distance between the burner devices must be at least 2 m; c) for boilers with manual furnaces of at least 5m.
3. Before the front of the boilers, it is allowed to install pumps, fans and heat shields, as well as to store the stock of solid fuel for no more than one change of operation of the boilers. The width of free passages along the front should not be less than 1.5 m. The installed equipment and fuel should not interfere with boiler maintenance.
4. When installing boilers that require side maintenance of the furnace or boiler (skimming, blowing, cleaning gas ducts, drums and collectors, removing the economizer and superheater packages, removing pipes, servicing burners), the width of the side passage must be sufficient for maintenance and repair, but not less than 1.5 m for boilers with a steam capacity of up to 4 t / h and not less than 2 m for boilers with a steam capacity of 4 t / h or more. Between the outer boiler and the wall of the boiler house, regardless of the boiler capacity, it is allowed to reduce the width of the side passage to 1.3 m.
5. In the absence of side maintenance of furnaces and boilers, at least one passage must be made between the boilers or between the outermost boiler and the boiler room wall. The width of this side passage, as well as the width between the boilers and the rear wall of the boiler room, must be at least 1 m. The width of the passage between the individual boiler parts protruding from the brickwork (frames, pipes, separators, etc.), as well as between these parts and protruding parts of the building (columns), stairs, work platforms, etc. should be at least 0.7 m. In the absence of a passage between the wall of the boiler lining and the wall of the boiler room building, the lining should not closely adjoin the building wall and must be at least 70 mm away from it.
6. The distance from the upper mark (platform) of the boiler maintenance to the lower structural parts of the boiler room covering located above it should be at least 2 m.In the absence of the necessary transition through the drum, steam chamber or economizer, the distance from them to the lower structural parts of the boiler room covering must be at least 0 , 7 m.
7. It is forbidden to install in the same room with boilers and economizers machines and devices that are not directly related to their maintenance, repair of boiler equipment or to the technology of generating steam. It is allowed to install steam power engines, water heaters, pumps and standby heat power engines, provided that these installations do not complicate the maintenance of boilers and economizers. Boilers and turbines of power plants can be installed in a common room or in adjacent rooms without the construction of dividing walls between the boiler room and the machine room.
8. The placement of boilers, superheaters and economizers in power trains, on cranes and other mobile vehicles is determined by the design organization based on the maximum convenience of maintenance and work safety.
Platforms and stairs
1. For convenient and safe servicing of boilers, superheaters and economizers, permanent platforms and stairs with handrails not less than 0.9 m high with continuous sheathing of handrails with a bottom not less than 100 mm should be installed. Transitions and staircases should have handrails on both sides. Sites longer than 5 m must have at least two stairs (exits) located at opposite ends. It is allowed to set up dead-end platforms with a length of more than 5 m with one exit intended only for the production of repair work.
2. Platforms and steps can be performed:
a) from expanded metal sheet; b) from corrugated sheet steel or from sheets with an uneven surface obtained by surfacing or by another method; c) made of profiled or strip (per edge) steel with a gap of no more than 30x30 mm.
The use of smooth platforms and steps of stairs, as well as their execution from bar (round) steel, is prohibited. Platforms and staircases in boiler rooms of semi-open and open types should be made of expanded metal, section or strip steel.
3. Ladders must have a width of at least 600 mm, a height between steps no more than 200 mm, a step width of at least 80 mm and every 3-4 m in height - platforms. Stairs with a height of more than 1.5 m should have an angle of inclination to the horizontal of no more than 50 ° C. For servicing deaerator tanks and other equipment that does not require frequent observation, as well as for access to hatches and manholes and for short staircases with a height of not more than 1.5 m, staircases with an angle of inclination to the horizontal of not more than 75 ° are allowed. Ladders with a height of not more than 3 m, intended for use during the boiler repair period, can be vertical.
4. The free passage width of platforms for servicing fittings, instrumentation, etc. should be at least 800 mm, for other platforms - at least 600 mm. The free height above walkways and stairs must be at least 2 m.
5. The vertical distance from the platform for servicing water-indicating devices to the middle of the water-indicating glass must be at least 1 m and not more than 1.5 m.In exceptional cases, when the boiler design cannot withstand the given dimensions, the indicated distance can be taken in the range from 0, 6 to 2 m.
6. In those cases when the distance from the operator’s working platform (stoker) to the upper platform of the boilers exceeds 20 m, a passenger-and-freight elevator should be installed.
Fuel supply and slag-ash removal
1. For boilers with a steam capacity of 2 t / h and above, operating on solid fuel, the fuel supply to the boiler room and the boiler furnace should be mechanized, and for boiler rooms with a total slag and ash output from all boilers in an amount of 200 kg / h or more (regardless productivity of boilers) ash and slag removal should be mechanized.
2. When equipping boiler rooms with mechanized ash removal, it is allowed to place mechanisms below the level of the territory directly adjacent to the boiler building in impassable channels and depressions, provided that access is secure for inspection and repair of these mechanisms. When arranging a passage corridor for periodic inspection and repair of ash removal mechanisms, it must have a height of at least 1.9 m and a width of at least 1 m in height to the lower parts of the protruding structures. The corridor must have two exits to the outside.
3. With manual ash removal of the hopper, the slag and ash removers should be equipped with devices for pouring ash and slag into the hoppers or trolleys with water. In the latter case, insulated chambers should be arranged under the hopper for installing the trolleys before the ash and slag are drained into them. Cells should have tight-fitting doors with glazed peepers and equipped with ventilation and lighting. The control of the hopper gate and slag pouring should be moved outside the chamber to a place safe for servicing. The lower parts of ash bins for manual transportation of sol: in trolleys should be located at such a distance from the floor level that the passage height under the bunker gate is at least 1.9 m from the floor; for mechanized hauling, this distance should be 0.5 m greater than the trolley height. The width of the passage of the ash room should be at least the width of the trolley, increased by 0.7 m on each side. Reducing the width is allowed only in the passages between the columns of the boiler foundation.
4. If ash and slag are scrapped from the furnace to the work site, then exhaust ventilation must be arranged in the boiler room above the cesspool and pouring focal residues.
5. In mine furnaces with manual loading for wood fuel or peat, loading bins with a lid and a hinged bottom should be arranged.
6. When burning liquid fuel, a drainage of fuel flowing out of the nozzles should be provided, excluding the possibility of it getting on the floor of the boiler room.
7. Shut-off valves must be installed on liquid fuel lines to be able to shut off the fuel supply to the boilers.
8. The gas equipment of boiler rooms should not impede the maintenance of boilers; all locking devices and measuring instruments should be convenient for maintenance.
9. It is not allowed to transfer boilers to the combustion of liquefied gas in operated boiler rooms, the floor level of which is below the level of the territory adjacent to the boiler room.
General requirements
1. The administration of the enterprise must ensure the maintenance of boilers, superheaters and economizers in good condition, as well as ensure safe conditions for their work by organizing the maintenance of repair and supervision in full compliance with the requirements of these Rules.
2. The administration of the enterprise is obliged to appoint the necessary number of engineering and technical workers and maintenance personnel to the boiler room. Responsible for the safe operation of boilers, superheaters and economizers is the head (manager) of the boiler room. In the absence of the head of the boiler room, the responsibility for the safety of the operation of boilers, superheaters and economizers should be assigned to one of the engineering and technical workers who have experience in operating boilers, superheaters and economizers and who have passed the knowledge test in the prescribed manner.
3. Engineers and technical workers directly related to the operation of boilers, superheaters and economizers should be tested for knowledge of these Rules before being appointed to a position and periodically, at least once every three years, in the enterprise commission, and in the absence of relevant specialists at the enterprise, in the commission of the parent organization.
4. Persons at least 18 years of age who have passed a medical examination, trained according to the relevant program and have a certificate of the qualification commission for the right to service the boiler can be allowed to service the boiler. Programs for training personnel serving boilers should be drawn up on the basis of standard programs approved in the manner established by the State Committee of the Council of Ministers of the USSR for vocational and technical education. Training and certification of personnel servicing boilers of power plants, which are subject to the Rules for the technical operation of power plants and networks, should be carried out in the manner prescribed by these Rules.
5. Certification of drivers (stokers) of boilers and water inspections should be carried out in permanent qualification commissions organized at specialized vocational schools, educational plants and other educational institutions. Certification is also allowed at enterprises and organizations that have the necessary conditions and specialists in agreement with the local authorities of Gosgortechnadzor. The participation of a representative of the local body of Gosgortechnadzor in the work of qualification commissions for certification of drivers (stokers) of boilers and water inspections is mandatory. The local authority of Gosgortekhnadzor must be notified about the day of the examinations no later than 10 days in advance.
6. The re-examination of the knowledge of the boiler room maintenance personnel should be carried out periodically, at least once every 12 months, as well as when moving to another enterprise and in cases of transferring to the maintenance of boilers of a different type or transferring the boilers they serve from solid fuel to liquid fuel in commissions directly at the enterprises or in organizations without the participation of a boiler supervisor. When transferring personnel to servicing gaseous fuel boilers, their knowledge should be checked in the manner established by the Safety Rules in the Gas Sector
7. The results of examinations and periodic testing of knowledge of service personnel should be recorded in a protocol signed by the chairman of the commission and its members and indicated in a special journal. Persons who have passed the exams are issued certificates signed by the chairman of the “commission and the inspector of boiler supervision.
Boiler maintenance requirements
1. It is forbidden to entrust the boiler driver (fireman) and the water inspection on duty with performing any other duties during boiler operation that are not provided for in the instructions.
2. It is forbidden to leave the boiler unattended by the operating personnel until the combustion stops, the fuel is removed from the furnace and the pressure in it is completely reduced to atmospheric pressure, except for boilers that do not have brickwork, in which the pressure drop to zero after removing fuel from the furnace is not necessary, if the boiler room is locked.
3. The operation of the boiler with chamber combustion of fuel can be allowed without constant supervision of the driver (stoker) if the boiler has automatic equipment that ensures its normal operation from the control and monitoring panel, as well as the boiler shutdown in case of violations of the operating mode that can cause damage to the boiler, with simultaneous signaling this to the control panel. In this case, it should be possible to stop the boiler at any time from the control panel.
4. It is allowed to operate drum boilers, in which the water level in the drums is at a height of more than 6 m from the boiler maintenance platform, without water inspections, provided that the requirements specified in paragraph 4 ("Water level indicators") are met. In this case, one of the remote pointers must be with a recording device.
5. The administration of the enterprise on the basis of the "Standard Instructions for the boiler room personnel", taking into account the characteristics of this boiler installation, should develop and approve in accordance with the established procedure production instructions for the boiler room personnel. The production instruction must be posted in a conspicuous place in the boiler room and issued to the operating personnel. In boiler houses of power plants, which are subject to the "Rules for the technical operation of power plants and networks", instructions may not be posted. For boiler elements with a steam superheat temperature of 450 ° C and above, in addition, there should be instructions for observing the creep and structural changes of the metal.
6. The boiler room must have a clock, telephone or sound alarm for calling in an emergency the representatives of the administration of the enterprise and communication of the boiler room with the places of steam consumption, and the waste heat boiler also for communication with the place of installation of the heat source.
7. Persons not related to the operation of boilers and boiler room equipment should not be allowed into the boiler room. In necessary cases, unauthorized persons may be allowed into the boiler room only with the consolation of the administration and accompanied by its representative. It is forbidden to store any materials and objects in the boiler room. The boiler room must be kept clean.
8. In the boiler room there should be a removable journal of the form established by the administration for recording the results of the verification of boilers and boiler equipment, water indicating devices, limit water level alarms, pressure gauges, safety valves, nutrient devices, automation equipment, time and duration of boiler purging, as well as other data as directed by the administration . The delivery and acceptance of boilers, superheaters, economizers and auxiliary equipment should be made out in this journal by the signatures of the persons responsible for the changes. The shift log also records the orders of the head of the boiler room or of the person replacing him about kindling or stopping the boiler (except in cases of emergency stop). The entries in the log should be checked daily by the employee responsible for the safe operation of boilers, with a receipt in the log.
9. When working in the boiler and flues for portable electric lighting, a voltage of not higher than 12 V should be applied; use of kerosene and other lamps with flammable materials is prohibited.
Checking safety devices, measuring instruments, fittings and feed pumps
1. Checking pressure gauges with their sealing (stamping) should be carried out at least once every 12 months in the manner established by the rules of the Committee of Standards, Measures and Measuring Instruments of the USSR. In addition, at least once every six months, the enterprise must check the working pressure gauges with a control pressure gauge or a verified working pressure gauge, which have the same scale and accuracy class as the pressure gauge being tested, with a record of the results in the audit log. Checking the correct operation of the pressure gauge using three-way valves or shut-off valves replacing them must be performed at least once per shift. Checking the serviceability of pressure gauges on boilers, superheaters and economizers with a working pressure of 100 kgf / cm2 and higher of thermal power plants can be carried out within the time period stipulated by the instruction of the USSR Ministry of Energy and Electrification.
2. Checking water indicating devices by blowing should be carried out for boilers with a working pressure of up to 24 kgf / cm2 inclusively at least once a shift, for boilers with a working pressure of 24 to 39 kgf / cm2 inclusively at least once a day, and for boilers with a working pressure over 39 kgf / cm2 in the terms established by the production instruction. Reconciliation of readings of reduced water level indicators with direct-indicating water indicating devices shall be performed at least once per shift.
3. Checking the serviceability of the safety valves by purging should be carried out at each start-up of the boiler, superheater and economizer in operation, as well as during their operation in the following periods: for boilers, superheaters and economizers with pressures up to 24 kgf / cm2 inclusive, each valve is checked at least once once a day, with a pressure from 24 to 39 kgf / cm2 inclusive, one valve of each boiler, superheater and economizer is checked one by one - at least once a day, with a pressure above 39 kgf / cm2 (including safety valves of intermediate superheaters) - in terms established by the instruction of the Ministry of Energy and Electrification of the USSR. Checking the correct operation of the safety valves of boilers, superheaters and economizers with a pressure of more than 24 kgf / cm2 is carried out in the presence of the person responsible for the change.
4. The serviceability of all feed pumps or injectors should be checked by short-term start-up of each of them: for boilers with a working pressure of up to 24 kgf / cm2 - at least once a shift, for boilers with a working pressure of over 24 kgf / cm2 - within the time frame established production instruction.
Emergency stop of boilers
1. The boiler must be stopped immediately in the cases stipulated by the production instructions, and in particular: a) if more than 50% of the safety valves or other safety devices replacing them cease to function; b) if the pressure has risen above the permitted one by more than 10% and continues to increase, despite the cessation of fuel supply, a decrease in draft and blast, and increased power to the boiler with water; c) with the loss of water; feeding the boiler with water is strictly prohibited; d) if the water level drops rapidly despite the increased water supply to the boiler; e) if the water level has risen above the upper visible edge and the water indicating device (overflow) and it is not possible to lower it by blowing the boiler; e) upon the termination of all nutrient devices; g) upon termination of all water-indicating devices; h) if cracks, bulges, gaps in their welds, breaks in two or more adjacent joints are detected in the main elements of the boiler (drum, manifold, chamber, flame tube, fire box, furnace cover, pipe grill, external separator, steam line) ; i) in boiler rooms operating on gas fuel, in addition, in cases provided for by the rules and safety instructions in the gas industry; j) in the event of a gas explosion in the gas ducts, interruption of power supply during artificial traction, as well as damage to the boiler elements and its wiring, creating a danger to maintenance personnel or the threat of destruction of the boiler; k) in the event of a fire in the boiler room or ignition of soot and fuel particles in the gas ducts that threaten the maintenance personnel or the boiler.
2. Possible reasons and the procedure for emergency stopping of the boiler must be indicated in the production instructions. The reasons for the emergency shutdown of the boiler must be recorded in the shift log.
Repair of boilers, superheaters and economizers
1. The administration of the enterprise (organization) must ensure timely repair of boilers, superheaters and economizers according to the approved schedule of preventive maintenance. Repair must be carried out according to the technical conditions and in accordance with the requirements of these Rules.
2. Each boiler room must have a repair log, in which, signed by the head of the boiler room or the person responsible for the safe operation of the boiler, information about the repair work performed that does not necessitate an early survey, and about stopping the boilers for cleaning or flushing must be entered. The replacement of pipes, rivets and the expansion of pipe connections with drums and chambers should be noted on the pipe (rivet) layout in the repair log. The repair log also reflects the results of the boiler inspection before cleaning, indicating the thickness of scale and sludge deposits and all defects revealed during the repair period.
3. Information about repair work that necessitates an early survey of boilers, superheaters and economizers, as well as data on materials and welding used during repairs, and information about the welder must be entered in the boiler passport.
4. Before starting any work inside the drum of the chamber or boiler manifold connected to other working boilers by common pipelines (steam line, feed, drainage and drain lines, etc.), as well as before inspecting or repairing pressure elements, if there is a risk of burns to people by steam or water, the boiler must be separated from all pipelines with plugs or disconnected; disconnected piping should also be plugged. It is allowed to shutdown boilers with a pressure above 39 kgf / cm2 by two shut-off devices if there is a drainage device between them with a nominal diameter of at least 32 mm, which has a direct connection to the atmosphere. In this case, the actuators of the valves, as well as the valves of the open drains should be locked so that the possibility of weakening their density when the lock is locked is excluded. The key to the lock must be kept by the boiler manager. When gas heating, the boiler must be reliably disconnected from the common gas pipeline in accordance with the instructions of the boiler maintenance company.
5. The plugs used to shut off the boiler, installed between the pipe flanges, must be of appropriate strength and have a protruding part (shank), which determines the presence of the plug supplied. When installing gaskets between the flanges and the plug, they must be without shanks.
6. The admission of people into the boiler and the opening of valves after removing people from the boiler should be carried out at a temperature not exceeding 60 ° C only with the written permission (along with the admission) of the head of the boiler room, issued in each case after carrying out an appropriate check.
7. Work of people in gas ducts can be carried out at a temperature not exceeding 60 ° C only after the place of work is ventilated and reliably protected from the penetration of gases and dust from operating boilers by closing and sealing the dampers with their locking or setting temporary brick walls. The time spent by people in the firebox (flue) at a temperature of 50-60 ° should not exceed 20 minutes. When operating on gaseous or pulverized fuels, the boiler must, in addition, be reliably separated from the common gas or dust pipe in accordance with the production instructions.
8. When disconnecting relevant sections of the pipeline, steam pipelines, gas pipelines and gas ducts, as well as on the starting devices of smoke exhausters, blowing fans and fuel feeders, “Do not turn on, people work” posters should be posted on gates, gate valves and dampers, and at the same time, starting devices of smoke exhausters, blowing fans and fuel feeders must be removed fusible links.
Registration, survey and permit for operation
check in
1. Boilers, independent superheaters, individual and group economizers must be registered with the local authorities of Gosgortechnadzor prior to commissioning. Boilers are not subject to registration with the Gosgortekhnadzor bodies, for which: (t - 100) V<= 5, где t - температура насыщенного пара при рабочем давлении, °С; V - водяной объем котла, м3.
2. Registration of the boiler, superheater and economizer is carried out on the basis of a written application, the administration of the enterprise that owns the boiler or the organization that leases them, with the submission of the following documents:
a) passports of the established form with the attachment of drawings of the actual design of the combustion device; b) the certificate of serviceability of the boiler, if it arrived from the manufacturer in assembled form (or moved from one place to another); c) certificates of the quality of installation indicating the design changes allowed; d) drawings of the boiler room (plan, longitudinal and cross sections); e) certificates of conformity of water treatment to the project; f) information on the availability and characteristics of nutritional devices.
The listed documents, in addition to the passport, must be signed by the head of the enterprise and bound together with the passport.
3. In the absence of a factory passport, it can be drawn up by an enterprise - the owner of a boiler, a superheater and an economizer, or by an appropriate organization on the basis of the manufacturer's documentation or according to the data of full-scale measurement, mechanical tests, chemical and metallographic studies of metal, its main elements and inspection of welded joints by non-destructive methods of flaw detection in accordance with the requirements of these Rules. The passport of the boiler, superheater and economizer must include the results of studies of the quality of the material and welded joints, as well as the strength calculation performed in accordance with the requirements of these Rules.
4. The installation quality certificate is issued by the organization that carried out the installation. The certificate must be signed by the head of this organization, as well as the head of the enterprise that owns the superheater boiler and economizer, and sealed. The certificate must contain the following data: name of the installation organization; enterprises - the owner of the boiler, superheater and economizer; manufacturer of the boiler, superheater and economizer and their serial numbers; information about the materials used by the installation organization in addition to those indicated in the passports; on welding, including the type of welding, the type and brand of electrodes, the names of welders and the numbers of their certificates, the results of testing control joints (samples); information about checking the pipe system by passing the ball and about flushing the boiler, superheater and economizer; about steeloscopy of boiler elements, superheaters operating at wall temperatures above 450 ° C; general conclusion on the conformity of industrial installation work with these Rules, the project, technical specifications and installation instructions for the boiler, superheater and economizer and their suitability for use at the parameters specified in the passport.
5. Boilers, superheaters and economizers after dismantling and installation at a new location must be re-registered.
6. The boilers of power trains, after arriving at a new place of work, must be registered with the local Gosgortekhnadzor body.
7. If the documentation complies with the requirements of these Rules, the local authority of Gosgortekhnadzor registers the boiler, superheater and economizer with the assignment of registration numbers and returns the passport to the owner of the boiler.
8. The response to the application for registration of the boiler, superheater and economizer must be given by the supervisor no later than five days from the date of receipt of the documents. In case of refusal to register the boiler, its owner must be informed about this in writing, indicating the reasons for refusal with reference to the relevant articles of the Rules.
9. Each boiler and group economizer must be clearly visible affixed with a plate with a format of at least 300x200 mm indicating the following data: a) registration number; b) permitted working pressure; c) the dates (year, month) of the next internal inspection and hydraulic test.
Technical inspection
1. Each boiler, superheater, economizer must be subjected to a technical examination prior to commissioning, periodically during operation and ahead of schedule, if necessary. Inspection of superheaters and economizers, which comprise one unit with the boiler, is carried out simultaneously with the boiler.
2. The administration of the enterprise is obliged to prepare and present the boiler, superheater and economizer for examination within the time specified in the passport, and provide the technical means necessary for the examination.
3. The administration of the enterprise is obliged to notify the boiler supervision inspector about the day that the boiler, superheater and economizer are ready for the initial, periodic or early examination, no later than 10 days in advance.
4. If it is not possible to send and arrive at the enterprise a boiler inspection inspector to inspect the boiler, superheater, economizer, the administration of the boiler owner can carry out the examination within the established time period only with the permission of the local Gosgortekhnadzor authority on its own responsibility. For this, by order of the head of the enterprise, a commission of competent engineering and technical workers should be created. The boiler approved by the commission is subject to compulsory inspection by the boiler supervision inspector within the period appointed by the commission, but no later than 12 months later.
5. The technical inspection of the boiler, superheater, economizer must be carried out by the boiler supervision inspector in the presence of the head (manager) of the boiler room or a person responsible for the safe operation of the boiler, superheater and economizer.
6. Technical inspection of the boiler, superheater and economizer consists of an internal inspection and a hydraulic test.
7. Internal inspection is aimed at: a) during the initial survey, establish that the boiler, superheater and economizer are built, installed and equipped in accordance with these Rules and the documents submitted during registration, and that the boiler and its elements are in good condition; b) during periodic and early surveys, establish the serviceability of the boiler and its elements and the reliability of its further safe operation.
8. During an internal inspection of the boiler and its elements, attention should be paid to identifying possible cracks, tears, holes, bulges and corrosion on the inner and outer surfaces of the walls, violations of the density and strength of welded, riveted and rolling joints, as well as damage to the lining that could cause a danger of overheating metal elements of the boiler.
9. The hydraulic test is aimed at checking the strength of the elements of the boiler, superheater and economizer and the tightness of their connections. The value of the test hydraulic pressure is not given in this manual. During the hydraulic test, certain requirements of paragraph 4 must be observed. The boiler, superheater and economizer must be submitted to the hydraulic test with fittings installed on them.
10. Initial technical examination of newly installed boilers, superheaters, economizers is carried out by a boiler inspection inspector after their installation and registration. Boilers to be lined can be inspected by the boiler inspector prior to registration.
11. Boilers that underwent internal inspection and hydraulic testing at the manufacturer and arrived at the installation site in assembled form, as well as boilers not registered with the supervisory authorities, are subject to initial technical examination at the installation site by the person responsible for the safe operation of boilers, superheaters and economizers ...
12. Boilers registered with the local Gosgortekhnadzor authorities that have not undergone assembled hydraulic inspection and hydraulic testing at the manufacturer, as well as boilers installed using welding, rolling or riveting of their elements, are subject to initial technical inspection by the boiler supervision inspector.
13. Periodic technical inspection of boilers, steam superheaters and economizers in operation registered with local authorities is carried out by the boiler supervision inspector in the following terms:
a) internal inspection - at least once every four years; b) hydraulic test - at least once every eight years. Before the hydraulic test, an internal inspection must be performed without fail.
14. The administration of the enterprise is obliged to independently inspect boilers, superheaters and economizers in the following cases: a) internal inspection - after each cleaning of internal surfaces or repair of elements, but at least after 12 months; this inspection is allowed to be combined with an internal inspection carried out by a boiler inspection inspector, provided that the gap between the inspection periods does not exceed three months; at thermal power plants, it is allowed to carry out internal inspections of boiler units during the period of their overhaul, but at least once every three years; b) internal inspection - immediately before the presentation of the boiler for examination by the inspector of the boiler supervision; c) hydraulic test with operating pressure - each time after cleaning the internal surfaces or repairing the boiler elements, superheater and economizer, if the nature and volume of the repair does not necessitate an early survey.
15. Periodic inspection of boilers, which are not subject to registration with the local authorities of Gosgortekhnadzor, is carried out by a person responsible for the safe operation of boilers, superheaters and economizers.
16. The day of the inspection of the boiler, superheater and economizer is set by the administration of the enterprise, while the boiler must be stopped no later than the period specified in the passport.
17. The local authority of Gosgortekhnadzor is granted the right, in exceptional cases, to extend the established period for the inspection of boilers up to three months upon a substantiated written request from the administration of the enterprise with the submission of data confirming the satisfactory condition of the boiler, and in case of positive results of the inspection of the boiler in working order by the inspector of the boiler supervision.
18. Before internal inspection and hydraulic testing, the boiler, superheater and economizer must be cooled and thoroughly cleaned of scale, soot and ash. Internal devices in the drum should be removed if they interfere with inspection. If in doubt about the good condition of the walls or seams, the person who conducts the survey has the right to demand the opening of the lining or the removal of insulation in whole or in part, and when conducting an internal inspection of the boiler with smoke tubes - complete or partial removal of the pipes. When inspecting once-through boilers, as well as other systems with tube bundles inaccessible for internal inspection, in necessary cases, it is necessary to require cutting out samples from pipes of heating surfaces in order to control the state of their inner surface.
19. Early technical inspection of the boiler, superheater or economizer should be carried out in the following cases: a) the boiler has been inactive for more than one year; b) the boiler was dismantled and re-installed; c) at least part of the sheet has been replaced or welding of boiler elements has been applied, with the exception of welding of single fittings, pipes and plugs; d) the bulges and dents of the main elements of the boiler were straightened; e) more than 25% of the total number of rivets in any seam is riveted; e) replaced by more than 15% of the bonds of any wall; g) after replacing the screen camera, superheater or economizer; h) more than 50% of the total number of screen and boiler pipes or 100% of overheating, economizer, smoke tubes were replaced at the same time; i) according to the condition of the boiler, the administration of the enterprise or the inspector of the boiler supervision consider such a survey necessary.
20. An early inspection of boilers registered with the local authorities of Gosgortekhnadzor is carried out by a boiler supervision inspector, and for boilers that are not subject to registration, by a person responsible for the safe operation of boilers, superheaters and economizers.
21. If during the technical examination of the boiler, superheater and economizer, no defects are found that reduce their strength, they are allowed to operate at nominal parameters until the next survey.
22. If defects are identified in which only temporary operation of the boiler, superheater and economizer is possible, the person who performed the examination may authorize the boiler to operate with a reduced period of the next examination.
23. If during the inspection of the boiler, superheater and economizer defects are found that reduce the strength of its elements (thinning of the walls, wear of bonds, etc.), then until the replacement of defective elements, further operation of the boiler can be allowed at reduced parameters (pressure and temperature). The ability to operate the boiler with reduced parameters should be confirmed by the strength calculation provided by the enterprise administration.
24. If, during the inspection of the boiler, superheater and economizer, defects are revealed, the cause of which is difficult to establish, the boiler supervision inspector is given the right to require the administration to carry out special studies, and, if necessary, provide a conclusion of specialized organizations or relevant specialists on the causes of defects, the possibility and conditions of further operation of the boiler ...
25. Depending on the condition of the elements of the boiler, superheater and economizer in the presence of defects (seams, metal delamination, cracks, breaks and swelling of pipes, etc.) that raise doubts about the quality or grade of metal, the boiler inspector is given the right to submit a requirement for mechanical tests of metallographic research and chemical analysis. In these cases, the boiler passport must indicate the reasons why a metal test is required, as well as the places from which samples should be taken.
26. If, during the inspection of the boiler, mechanical tests of the metal of drums or other main elements of the boiler were carried out and the results obtained for carbon steel are lower than the values \u200b\u200bindicated in the table, then further operation of the boiler should be prohibited. The permissible values \u200b\u200bof the indicators of the mechanical properties of the metal of the boiler elements under a pressure of 39 kgf / cm2 and more, made of carbon and alloy steel, are established by the local bodies of Gosgortekhnadzor in each case according to the conclusion of the manufacturer or a specialized organization.
27. If during the inspection of the boiler leaks are detected (leaking, traces of soaking, build-up of salts) in the places of rolling or rivet joints, then further operation of the boiler can be allowed only after examining the defective compounds for the absence of intergranular corrosion. If cracks are found, the boiler must be repaired. Stamping, weld-on and expansion of loose connections without research are not allowed.
28. If, during the inspection of the boiler, superheater and economizer, it turns out that it is in an emergency condition or has serious defects that raise doubts about its strength, further operation of the boiler should be prohibited.
29. If during the analysis of defects revealed during the inspection of boilers, superheaters and economizers, it will be determined that their occurrence is connected with the operation mode of boilers in this enterprise or is peculiar to boilers of this design, then the person who conducted the examination should require an extraordinary examination of all installed at this enterprise boilers, the operation of which was carried out according to the same regime, or, accordingly, of all boilers of this design with a notification to the local authority of the Gosgortekhnadzor.
30. The results of the survey and a conclusion on the possibility of operation of the boiler, superheater and economizer, indicating the permitted pressure and the timing of the next survey should be recorded in the boiler passport. At an early survey, the reason for the need for such a survey must be indicated. If during the survey additional tests and studies were carried out, then the types and results of these tests and studies should be recorded in the boiler passport, indicating the places of sampling or areas subjected to tests, as well as the reasons that caused the need for additional tests.
31. If, as a result of the survey, the further operation of the boiler, superheater and economizer is prohibited, the operating pressure is reduced or the period of the next survey is reduced, then a corresponding motivated entry must be made in the boiler passport. The record of the survey is signed by the person who performed the survey. If the survey was carried out by the commission in accordance with paragraph 4, the record is signed by all members of the commission, and a copy of this record is sent to the local authority of the State Technical Supervision Authority no later than five days after the survey.
Permit to start up newly installed boilers
1. Each newly installed boiler, superheater and economizer can be put into operation on the basis of a written order from the administration of the enterprise after acceptance by the acceptance committee of the boiler, superheater and economizer from the installation organization and with the permission of the boiler inspector.
2. A permit to operate a boiler, superheater and economizer is issued on the basis of the results of the initial technical examination and inspection during steam testing, during which it is checked:
a) the availability and serviceability of the fittings required by these Rules, instrumentation and safety devices; b) the health of nutritional devices and their compliance with the requirements of these Rules; c) the compliance of the water regime of the boiler with the requirements of these Rules; d) the correct connection of the boiler to the common steam line, as well as the connection of the supply and purge lines; e) the availability of certified service personnel, as well as engineering and technical workers who have passed the knowledge test; f) availability of production instructions for boiler room personnel, shift and repair logs; g) the compliance of the boiler room with the requirements of these Rules. A permit for the operation of a boiler, superheater and economizer, subject to registration with the local authorities of Gosgortekhnadzor, is recorded in the passport of the boiler, superheater and economizer by the boiler supervision inspector, and not subject to registration - by the person responsible for their safe operation.
Monitoring compliance with these rules
1. Control over compliance with these Rules is carried out by the local authorities of Gosgortechnadzor by conducting periodic inspections of enterprises operating boiler plants and manufacturing plants in accordance with the methodological instructions, instructions and other guidance materials of the Gosgortechnadzor.
2. If during the inspection of the manufacturer it will be established that in the manufacture of boilers, superheaters, economizers and their individual elements, violations of these Rules are allowed, then depending on the nature of the violation, the terms for their elimination are established or further production is prohibited.
3. If, during the inspection of boilers, superheaters and economizers in operation, defects in their elements or violations of the Rules are revealed that threaten safety during further operation, and also if the period for their next survey has expired or the maintenance personnel are not trained, then the operation of the boiler, superheater and economizer should be prohibited. The reason for the ban must be recorded in the passport with reference to the relevant articles of these Rules.
Investigation of accidents and accidents
1. The administration of the enterprise - the owner of them is obliged to immediately notify the local Gosgortekhnadzor body about every accident and every serious or fatal case associated with an accident or maintenance of the boiler, superheater and economizer.
2. Prior to the arrival of a representative of Gosgortekhnadzor to the enterprise to investigate the circumstances and causes of the accident or accident, the administration of the enterprise is obliged to ensure the safety of the entire situation of the accident (accident), if this does not pose a danger to people's lives and does not cause further development of the accident. Investigation of accidents and accidents should be carried out in accordance with the procedure established by Gosgortekhnadzor.
Final provisions
1. The need and terms for bringing the boilers, superheaters and economizers operating, as well as manufactured or in the process of manufacturing, installation or reconstruction in accordance with these Rules at the time of entry into force of these Rules, are established in each individual case by the Gosgortechnadzor district administration.
2. With the entry into force of these Rules, the "Rules for the Construction and Safe Operation of Steam Boilers", approved by the USSR State Technical Supervision Service on March 19, 1957, become invalid.
4-1. REQUIREMENTS OF THE GOSGORTEKHNADZOR RULES
The operation of steam and hot water boilers must be carried out in strict accordance with the "Rules for the construction and safe operation of steam and hot water boilers" of the USSR Gosgortekhnadzor. The design of the boiler, superheater and water economizer should be reliable and safe in operation, and should also allow inspection, cleaning with the use of mechanization, blowing, washing and repair of all elements of the unit.
The design and hydraulic circuit of the boiler, superheater and water economizer should provide reliable cooling of the walls of the elements under pressure. Placement of non-insulated elements of drums and collectors in the furnace space and in flues is allowed only if the elements are reliably cooled from the inside by liquid. During firing up and normal operation, all boiler elements must warm up evenly and be able to move freely due to thermal expansion. Boilers with a capacity of 10 t / h and above should have reference frames (movement indicators) that allow controlling the movement of elements due to thermal expansion.
The design organization is responsible for the correct design of the boiler, superheater, economizer and its elements, strength analysis and choice of materials, manufacturing quality is the manufacturer, installation and repair is the organization
the nations that performed these works. Changes to the design of the boiler can only be made by agreement with the manufacturer or a specialized organization that has the right to reconstruct the boiler units.
Each boiler unit is equipped with the required number of manholes, hatches, peepers and furnace doors used during operation to control its operation and repair.
In accordance with the "Rules" of the Gosgortekhnadzor, steam and hot water boilers are equipped with devices and devices that ensure safe operating conditions. Such devices include: boiler safety valves, gas duct safety devices, boiler water level indicators, feed pumps, measuring instruments and safety devices.
Steam boilers with a capacity of more than 100 kg / h must have at least two safety valves: one control and one working. With two safety valves and a non-shut-off superheater, one valve (control) is installed on the outlet header of the superheater. When operating steam boilers, the safety valves are adjusted in accordance with the data in table. 4-1. In this case, in order to avoid the destruction of the superheater, the first must always open and. the last to close the safety valve installed on the outlet manifold of the superheater.
At least two safety valves are also installed on hot water boilers. At the same time, safety valves may not be installed on direct-flow hot water boilers with chamber furnaces equipped with safety automation. The safety valves of boilers are regulated at the time of opening opening at a pressure not exceeding 1.08 of the working pressure in the boiler.
Economizers that can be switched off on the water side are equipped with one safety valve at the water inlet and one / one safety valve at the outlet of the economizer! The valve is installed at the water inlet to the economizer after the disconnecting organ, and at the outlet from the economizer -j-to the shutdown organ. The safety valve at the water inlet to the economizer should open when the pressure is 25% higher, and at the outlet of the economizer, it must open at 10% of the working pressure in the boiler.
The safety valves of the boiler, superheater and water economizer should be systematically checked. Checking the serviceability of safety valves is carried out by blowing (“manual detonation”). The check is performed at each start-up of the boiler, superheater and economizer, as well as during their operation. For boilers, superheaters and economizers operating at pressures up to 2.35 MPa inclusive, each valve is checked at least once a day, and at a pressure of 2.35 to 3.82 MPa inclusive, it is performed alternately, but at least one valve per day. Checking the safety valves is carried out in the presence of the shift supervisor and is recorded in the logbook.
The main problems with the operation of the safety valves are: steam passage, delay when lifting and frequent actuation with sharply fluctuating loads. The passage of steam by the valve leads to its premature wear, therefore, after checking or actuating the valve, make sure that it is tight. The passage of steam can occur due to skewing, getting foreign objects under the valve, spontaneous movement of the load, etc. The valve is delayed when it is attached, spontaneously moving the load, with an increase in pressing on the spring, when the guiding ribs in the socket and rod stick the place of its passage through the lid. In order to avoid frequent valve actuation under fluctuating load, the pressure in the boiler is maintained at 0.10-0.15 MPa less than the working one for which the valves are adjusted.
To protect the lining and flues from destruction during explosions, boilers with chamber furnaces (burning of pulverized, liquid, gaseous fuels), as well as with a shaft furnace for burning peat, sawdust, shavings and other small industrial waste, are equipped with explosive safety valves. In fig. 4-1 shows the designs of the safety valves used. The valves are installed in the lining of the furnace, the last gas duct of the boiler, economizer and ash collector. It is allowed not to install explosive valves in the lining of boilers with a single stroke of combustion products, as well as in flues in front of smoke exhausters.
For boilers with a capacity of less than 10 t / h, the number, location and dimensions of explosive safety valves are set by the design organization. Typically, design organizations select the area of \u200b\u200bthe explosion valves for these boilers on the basis of 250 cm 2 of the area of \u200b\u200bthe explosion valve per 1 m 3 of the volume of the furnace or boiler flue gas ducts. As an example in fig. 4-2 shows the placement of explosive safety valves on boilers of the DKVR type. For boilers with a capacity of 10 to 60 t / h in the upper part of the lining above the furnace
Explosive valves are installed with an area of \u200b\u200bat least 0.2 m 2. At least two safety valves with a total minimum cross-section of 0.4 m 2 are installed on the last flue of the boiler, the flue of the water economizer and the flue of the ash collector. When using explosive safety valves made of asbestos, care must be taken to ensure that they are intact. Experience shows that due to pulsations in the furnace, the valve may rupture, which leads to an increased suction of cold air. When making explosion valves in the form of hinged doors, it is necessary to check the tightness of the valve to the frame.
Water indicating devices and "lowered" level indicators installed at the boiler service area must be checked regularly. Water-indicating devices of boilers operating at pressures up to 2.35 MPa are checked every shift, and boilers at pressures greater than 2.35 MPa - once a day. Comparison of readings of reduced level indicators and water indicating devices should be made at least once per shift with a record of) the operation performed in the logbook.
During the operation of water-indicating devices, the following malfunctions are observed in their operation: clogging of the valves, "steam passage through leaks, fragility of the glass. When steam passes through leaks in the valve of the upper head, the water level in the water-indicating glass will be higher than the actual level. When steam passes through leaks in the valve of the lower head," the water level in the indicating glass will be underestimated
wives To eliminate the fragility of the glass, it should be boiled in clean lubricating oil for 20-30 minutes and then slowly cooled.
When operating the equipment of the boiler shop, the serviceability of all installed feed pumps is systematically checked. For boilers with a pressure of up to 2.35 MPa, each of the pumps is briefly put into operation at least once per shift, and for boilers with high pressure - within the time frames provided for by the production instructions, but at least once every 2-3 days. During a test run of the pumps, they check the pressure they create, the absence of leakage through leaks, bearing heating, vibration amplitude, and the pump drive is in good condition (electric motor, turbine, steam engine).
To control the operation of the boiler and to regulate the combustion process, a set of measuring instruments is installed. The scope of the boiler thermal control is selected depending on the productivity of the latter, the type of fuel and the method of its combustion, the design features of the boiler and other factors. However, each boiler unit in accordance with the "Rules" of the Gosgortekhnadzor must have a certain minimum number of devices, without which its operation is not allowed.
The steam boiler must have devices for measuring the steam pressure in the boiler drum and after the superheater, the feed water pressure before the body regulating its supply to the boiler, the water pressure at the inlet and outlet of the economizer that can be disconnected by water, the temperature of the superheated steam before the main steam valve of the boiler, steam temperature before and after the desuperheater, feed water temperature before and after the water economizer.
A hot water boiler must necessarily have instruments for measuring the pressure of water at the inlet and heated water at the outlet of the boiler, water pressure on the suction and discharge lines of the circulation pump, water pressure on the boiler supply line or heating system make-up, water temperature at the inlet and outlet of the boiler.
On steam boilers with a capacity of more than 10 t / h and hot water boilers with a capacity of more than 5815 kW, a recording pressure gauge must be installed. On steam boilers with natural circulation with a capacity of more than 20 t / h and direct-flow boilers with a capacity of more than 1 t / h, as well as on hot water boilers with a capacity of more than 1163 kW, the device for measuring the temperature of superheated steam and heated water must be recording. The pressure and temperature of hot water in boilers are measured between the boiler and the shut-off element.
In boiler units burning liquid fuel, its temperature and pressure are measured in front of the nozzles. When ra-
for gaseous fuels, the pressure of gas and air in front of each burner after the regulating bodies, as well as the vacuum in the upper part of the combustion chamber, should be measured.
The service personnel is obliged to systematically monitor the correctness of the readings of the instrumentation. L Boiler operators check gauges at least once per shift using three-way valves or valves that replace them. The engineering and technical staff of the boiler department checks the working pressure gauges at least once every six months by comparing their readings with the control pressure gauge. The check is recorded by an entry in the audit trail.
It is not allowed to use manometers without a seal, a stamp or with an expired check date, with broken glass or other damages that affect the accuracy of the readings, with an arrow that does not return to the zero position when the manometer is turned off (a deviation from the zero position by an amount not exceeding half the error is allowed pressure gauge).
In order to increase reliability, boiler units are equipped with safety devices that stop the operation of the boiler in case of emergency. Boilers with a steam capacity of 0.7 t / h and above must have automatically operating audible alarms for the lower and upper limit levels of water in the boiler drum. If these boilers have chamber furnaces, an automatic device is additionally installed that cuts off the fuel supply to the burners (dust, gas, fuel oil) in the event of a decrease in the water level in the drum beyond the permissible limit established by the manufacturer.
Direct-flow hot water boilers with chamber furnaces are equipped with automatic devices that cut off the fuel supply to the burners, and boilers with layer furnaces are equipped with devices that turn off fuel feeding mechanisms (fuel feeders, spreaders, chain grates) and draft machines, in the following cases:
a) increase the water pressure in the outlet manifold of the boiler
up to 1.05 of the pressure obtained when calculating the strength of the pipeline and boiler;
b) lowering the water pressure in the boiler outlet manifold
to a value corresponding to the saturation pressure at the maximum operating temperature of the water leaving the boiler;
c) increasing the temperature of the water leaving the boiler to
the values \u200b\u200bare 20 ° C lower than the saturation temperature, which corresponds to the working water pressure in the boiler outlet manifold;
d) such a decrease in water consumption through the boiler, at which
torus subcooling of water to boiling at the outlet of the boiler at max-
maximum load and operating pressure in the outlet manifold reaches 20 ° C.
Safety valves on a continuous-flow boiler with a chamber furnace may not be installed if the specified protection is provided. Exceeding the specified value by the temperature of the heated water is dangerous, since it can cause water hammer due to partial vaporization. To avoid local boiling, the average water velocity in individual heated pipes must be at least 1 m / s. The temperature of the heated water can reach the limit value due to insufficient working pressure, increased boiler boost or a noticeable decrease in water consumption. In operation, water consumption must not be reduced in comparison with the minimum. Minimum allowable flow rate (in kg / s)
where Q max is the maximum boiler power, kW; t s- saturation temperature at operating pressure at the outlet of the boiler, ° С; t in- water temperature at the inlet to the boiler, C C.
When burning gaseous fuels, in addition to the specified safety devices, steam and hot water boilers must be equipped with automatic equipment to ensure the gas supply is cut off in case of:
a) deviations of gas pressure within unacceptable limits;
b) flame extinguishing at least on one of the main burners;
c) traction disturbances (increase or decrease in vacuum
in the upper part of the furnace to within unacceptable limits);
d) stopping the supply of air or reducing its pressure in front of the burners beyond the set limit (for boilers,
equipped with forced air burners).
In order to increase safety when burning gaseous fuels, the gates of the flues should have openings with a diameter of at least 50 mm for continuous ventilation of the furnace and flues. The removal of combustion products from boilers, in which gas is burned, and boilers, in which other fuels are used, into a common bohr is allowed only for already existing boiler houses converted to gas. In this case, gaseous fuel units should only be started when the remaining units running on other fuels are stopped. If the shutdown of these units when starting one of the gas boilers is impossible, then special safety measures are developed, agreed with the local Gosgortekhnadzor body.
The safety devices of the boiler unit are systematically checked for operation within the time specified by the plant.
manufacturer, and always at every stop of the boiler. In the boiler room, a schedule for routine repair and inspection of all installed instrumentation and safety devices, approved by the chief engineer of the enterprise, is usually drawn up.
STEAM BOILERS
When operating vertical-cylindrical boilers, special attention should be paid to systematic monitoring of the condition of the heating surface. The most common damages to vertically cylindrical boilers are bulges and cracks in the furnace sheets. In this regard, in boilers of the MZK type, the combustion chamber is covered with protective refractory lining, the integrity of which must be systematically monitored. When setting up the boiler and setting up the automation, the air mode of the furnace must be selected especially carefully in order to avoid the appearance of chemical underburning during operation, since the presence of the latter leads to the deposition of soot on the heating surfaces, the cleaning of which is extremely difficult. A complete analysis of the combustion products should be carried out periodically and the change in the temperature of the flue gases should be monitored. An increase in the flue gas temperature after starting the boiler indicates that the heating surface is dirty.
Vertical water tube boilers, currently produced by industry, have a horizontal or vertical orientation of heating surfaces. Of the old types of horizontal orientation boilers, DKVR boilers of the Biysk boiler plant are used in large numbers. DKVR boilers were developed for burning solid fuels, but were later adapted for burning liquid and gaseous fuels.
The operating experience and inspection of DKVR boilers, produced by CKTI, showed that the main disadvantages in their work are: significant air suction into the gas duct of convective bundles (in heavy lining Aa K \u003d 0.4-f-0.9; and in lightweight lining with metal sheathing Yes k \u003d 0.2-t-0.5) and especially in the flue of cast-iron water economizers; insufficient degree of factory readiness; long terms of installation; lower operational efficiencies in comparison with the calculated ones. Fuel burnout due to air suction is estimated from 2 to 7%. Therefore, during the operation of DKVR boilers, it is necessary to systematically eliminate leaks that appear in the place of insulation of the upper drum.
When operating on gas and fuel oil of DKVR boilers, the part of the upper drum located in the combustion chamber must be protected from radiation. Operating experience has shown that the protection of the drum by means of shotcrete is fragile and is destroyed within one to two months. More reliable drum protection
shaped refractory brick. The design of the refractory brick fastening is shown in Fig. 4-3.
In connection with the indicated shortcomings of boilers of the DKVR type, TsKTI together with BiKZ developed DE-type gas-oil boilers for burning gas and fuel oil, and boiler units of the KE type for burning solid fuel based on DKVR boilers. Boilers type DE and KE are delivered in full factory readiness.
DE boilers have a number of design features: upper and lower drums of the same length; from convective-
the combustion chamber is separated by a gas-tight partition; pipes of the partition and the right side screen, which also covers under and the ceiling of the furnace, are introduced directly into the upper and lower drums; the ends of the pipes of the rear and front screens are welded to the upper and lower branches of C-ob-different collectors; all screens of the combustion chamber and the partition separating the firebox from the convective gas duct are made of pipes, between which spacers are welded to ensure the required density; the boiler lining is made of slabs, which have a lining about 1 mm thick on the outside.
When operating boilers with a horizontal orientation, having lower distributing and upper collecting headers, careful control should be exercised over the condition of the pipes of the screen heating surfaces, since the circulation of the steam-water emulsion in them is less reliable. To increase the reliability of circulation in these boilers, the installation of recirculation pipes is provided (for example, at the DKVR-20 boiler). Recycling is called lowering unheated pipes connecting the upper collector of the circuit with the lower.
 |
During operation of the boiler unit, individual pipes of the heating surface may fail. In this case, temporarily, until the pipes are replaced, a plug is installed. For boilers operating at pressures up to 1.27 MPa, it is recommended to use the plug shown in Fig. 4-4. The plug consists of two parts: a pipe cut from the pipe, and a bottom. The branch pipe is rolled into the hole, and then from the side of the inner surface of the drum, the bottom is welded or installed on the thread. When welding the bottom, heating of the rolling joint is not allowed in order to avoid violation of its density.
When starting and operating boilers DKVR and KE, it is necessary to monitor the thermal expansion of the front ends of the side screen chambers and the rear bottom of the lower drum, on which benchmarks are usually installed.
The reliability of horizontal orientation boilers largely depends on the kindling mode. To reduce the kindling time and reduce the difference in water temperature in these boilers, you should use a device for heating water in the lower drum. For this, steam is supplied from the operating boilers through the steam supply line to the lower drum before starting the furnace. It is recommended to heat the water in the boiler to a temperature of 90-100 ° C. The steam heating of the lower drum is stopped when the pressure in the boiler is equal to 0.75 of the heating steam pressure, and after that the furnace is started up, melting it with fire heating. The pressure rise on boilers of horizontal orientation, designed for a pressure of 1.27 MPa, is carried out so that 1.5 hours after kindling the pressure in the drum is 0.1 MPa, after another 2.5 hours it is 0.4-0.5 MPa and after 3 hours - 1.27 MPa.
Currently, the Belgorod Power Engineering Plant (BZEM) produces many modifications of vertical orientation boiler units with a capacity of up to 75 t / h with a pressure of 1.4-4.0 MPa. All boilers of vertical orientation have a U-shaped arrangement of heating surfaces and continuous shielding of the combustion chamber. The boilers are quite reliable in operation and have a high maintainability. The main disadvantage of boilers in operation is the increased suction of cold air into the gas ducts from the furnace to the last heating surface (Aa \u003d 0.25 ^ 0.35).
When burning solid fuels with a high ash content, it is necessary to monitor the wear of the heating surface
boiler. Ash wear depends on the rate of combustion products and the concentration of ash and fly ash. Especially dangerous are the increased local velocities and concentrations that are observed in gas corridors between the walls of the gas duct and the pipes, as well as in the places where individual pipes and coils are scanned (violation of fastenings and the appearance of various gaps between pipes and coils for the passage of combustion products). Pipes located near leaks in gas partitions and in the zone of rotation of combustion products are also subject to greater wear.
When operating any boiler units, engineering and technical personnel should pay special attention to the timely detection of damage to the pipes of the heating surface. When steam is formed in the pipes of the boiler, and especially the superheater, by fistula, steam and water coming out of them at high speed, mixing with ash, intensively destroy neighboring pipes. The appearance of fistulas is also dangerous when burning fuel oil.
Leaks in the pipes of the heating surface of the boiler, superheater and water economizer can be identified by noise in the gas ducts, a decrease in the water level in the boiler drum, discrepancy between the readings of the steam meter and water meter, the appearance of water in slag and ash bins. During the shift, it is necessary to bypass the boiler at least twice, looking through the peepers on the state of the heating surface, listening to the firebox, superheater gas flue, boiler and water economizer gas ducts.
Failure of pipes of the heating surface of steam boilers is also observed due to a violation of water circulation. Therefore, in operation, in order to increase the reliability of circulation, it is necessary to monitor the maintenance of the correct combustion mode, ensure uniform water supply to the boiler, prevent sharp fluctuations in steam pressure and water level in the boiler drum, prevent slagging of the heating surface, monitor the cleanliness of the inner surface of the pipes, control the density of the blowdown fittings.
The correct combustion mode is understood as the absence of thermal imbalances in the operation of the furnace and the first gas ducts of the boiler, as well as the blow of the torch into the screens and lining, the end of the combustion process within the furnace chamber, the maintenance of an optimal excess of air in the furnace, the absence of slagging, and the gradual change of force if necessary, maintaining optimal dust fineness and good atomization of liquid fuel, uniform distribution of fuel on the grate during layered combustion.
The pressure in the boiler should be increased gradually, especially at low boiler load, since with intensive forcing of the furnace, the heat perception of the wall tubes increases noticeably, and the steam content increases much more slowly, because part of the heat is spent on heating water to a higher temperature.
saturation ratio corresponding to increased pressure. The pressure should be raised so that at reduced loads it grows at about 400 Pa / s, and at nominal speeds at 800 Pa / s. In the event of a sudden load drop, the furnace forcing should be immediately reduced to avoid overheating of the wall tubes due to impaired circulation.
When operating the valve installed on the boiler, it is necessary to monitor its tightness, the absence of vapor through flange connections or stuffing box packing, and the ease of movement of the spindle when opening and closing the valve. Valves and valves that are used to control the flow of water or steam wear out especially quickly. Before each start-up of the boiler unit, all installed fittings must be checked for ease of movement by opening and closing it. During the operation of the boiler unit, the tightness of the fittings is checked by feeling the pipeline, which, when the valve is closed, must be cold.
When inspecting the boiler internally, the engineering and technical personnel must pay attention to the condition of the following elements. In drums, the internal surfaces, welded and riveted seams, the ends of rolled or welded pipes and fittings are examined. Damage in the riveted seams of vertical water tube boilers occurs mainly in the lower drums, at the junction of the longitudinal and transverse riveted seams. Intergranular cracks can appear in the tube sheets of drums, as well as in the places where feed water and phosphates are introduced. The internal surfaces of the boiler can show corrosive wear, mainly at the points of feed water intake, poor water circulation and sludge deposits.
When inspecting the pipes, corner screen pipes, horizontal and slightly sloping sections of the boiler pipes are checked. The most common defects in wall and boiling pipes are annular and longitudinal cracks, holes, fistulas, local thinning of the pipe walls and deformation of pipes due to scale deposits or disturbed circulation.
At the drums heated by the combustion products, the heating places in which bulges can form are examined. The condition of the shotcrete, which protects the drum from overheating, is checked. Cracking is possible in the welded seams of drums and collectors.
The outer surface of the pipes is inspected from the furnace and flues. Tears, bumps, deflections, and tearing of pipes from tube sheets are most often found in the first rows of pipes facing the furnace. In addition, pipe wear due to ash is checked. Pipe wear is detected using special patterns.
It is very important for industrial and hot water boiler units to take measures to prevent corrosion of the internal heating surfaces during stops for short or long periods. In this case, the following cases are distinguished:
a) preservation for a period of less than three days (when the boiler stops without opening the drum) using steam from a continuous purge separator or from other boilers;
b) conservation for more than three days (if the boiler is stopped without opening the drum) by connecting the boiler to a pipeline with deoxygenated condensate or feed water with a pressure of 0.3-0.5 MPa;
c) preservation for any period (when the boiler is stopped with the drum opened) with the superheater filling with condensate containing ammonia (ammonia concentration 500 mg / kg).
Canceled due to exit.
The rules for the design and safe operation of steam and hot water boilers establish requirements for the design, construction, materials, manufacture, installation, adjustment, repair and operation of steam boilers, autonomous superheaters and economizers with a working pressure of more than 0.07 MPa (0.7 kgf / cm 2 ), hot water boilers and stand-alone economizers with water temperatures above 115 ° C.
The rules are mandatory for executives and specialists involved in the design, manufacture, installation, commissioning, repair, technical diagnosis, inspection and operation of boilers, autonomous superheaters, economizers and pipelines within the boiler.
In connection with the entry into force of these Rules after their official publication, the Rules for the Construction and Safe Operation of Steam and Hot Water Boilers (Order of the Gosgortekhnadzor of Russia dated 17.07.03 No. 156) are considered invalid.
I. General Provisions
1.1. Purpose and scope of the Rules
1.2. Responsibility for violations of the Rules
1.3. Boilers and semi-finished products purchased abroad
1.4. The procedure for investigating accidents and accidents
II. Design
2.1. Project development
2.2. Changing boiler projects
III. Design
3.1. General Provisions
3.2. Water level position
3.3. Lazes, hatches, covers and fire doors
3.4. Safety devices for furnaces and gas ducts
3.5. Cast Iron Economizers
3.6. Bottoms and tube sheets
3.7. Welded joints, location of welds and holes
3.8. Curved elements
3.9. Rolling Compounds
3.10. Purge, Drain, and Drain Systems
3.11. Burner devices
IV. Materials and semi-finished products
4.1. General Provisions
4.2. Steel semi-finished products. General requirements
4.3. Sheet steel
4.4. Steel pipes
4.5. Steel forgings, stampings and rolling
4.6. Steel castings
4.7. Fasteners
4.8. Iron castings
4.9. Non-ferrous metals and alloys
4.10. Requirements for new grades of steels
V. Manufacturing, installation and repair
5.1. General Provisions
5.2. Cutting and deforming semi-finished products
5.3. Welding
5.4. Heat treatment
5.5. Control
5.6. Visual and measuring control
5.7. Radiographic and ultrasonic testing
5.8. Capillary and magnetic particle inspection
5.9. Styloscopy control
5.10. Hardness measurement
5.11. Control by rolling a metal ball
5.12. Mechanical tests, metallographic studies and intergranular corrosion tests
5.13. Quality Assessment Standards
5.14. Hydraulic tests
5.15. Correction of defects in welded joints
5.16. Passport and labeling
VI. Armature, devices and nutrient devices
6.1. General Provisions
6.2. Safety devices
6.3. Water level indicators
6.4. Pressure gauges
6.5. Temperature Measuring Instruments
6.6. Shut-off and control valves
6.7. Safety devices
6.8. Nutritional devices
Vii. Boiler room
7.1. General Provisions
7.2. Lighting
7.3. Placement of boilers and auxiliary equipment
7.4. Platforms and stairs
7.5. Fuel supply and ash removal
VIII. Water-chemical regime of boilers
8.1. General requirements
8.2. Requirements for the quality of feed water
8.3. Boiler water quality requirements
IX. Organization of safe operation and repair
9.1. Organization of safe operation
9.2. Service
9.3. Checking instrumentation, automatic protections, fittings and feed pumps
9.4. Emergency stop of the boiler
9.5. Organization of repair
X. Registration, technical examination and permission to operate
10.1. check in
10.2. Technical inspection
10.3. Commissioning works
10.4. Permit to operate newly installed boilers
Xi. Additional requirements for boilers operating with high-temperature organic coolants
11.1. General Provisions
11.2. Design
11.3. Fittings
11.4. Liquid level indicators
11.5. Pressure gauges
11.6. Temperature Measuring Instruments
11.7. Safety valves
11.8. Expansion vessels
11.9. Automatic protection
11.10. Pumps
11.11. Installation and operation
XII. Additional requirements for recovery boilers
12.1. General Provisions
12.2. Construction, equipment and control
12.3. Installation and operation
XIII. Additional requirements for gas tube boilers
13.1. General Provisions
13.2. Design
13.3. Automatic protection
Xiv. Monitoring compliance with these rules
Appendix 1. Brief table of relationships between units of the International System (SI) and other units of physical quantities adopted in this Regulation
Appendix 2. Basic terms and definitions
Appendix 3. Symbols and units of measurement
Appendix 4. Boiler passport (autonomous superheaters and economizer)
Appendix 4a. Boiler passport
Appendix 5. Materials used for the manufacture of boilers, superheaters, economizers operating under pressure
Appendix 6. Division of steels into types and classes
Appendix 7. Definition of concepts of the same type and control welded joints
Appendix 8. Standards for assessing the quality of welded joints
All boilers are operated in accordance with the requirements specified by the Gosgortechnadzor inspection. If they are not met, fires and explosions may occur in boilers. The reasons for the explosions include:
· Malfunction of control and (and) safety devices for controlling the operating modes of the boiler (safety valves, manometers, water indicating devices);
Violation of the process of preparation of a combustible mixture, for example, due to a malfunction of the nozzle, emergency stop of the fan, etc.);
· Decrease in the strength of the boiler walls as a result of corrosion, overheating, etc .;
· Operation of the boiler without supervision;
· Untimely technical inspection of the boiler;
· A large layer of scale on the walls;
· Maintenance of boilers by untrained personnel.
Boilers with excess steam pressure over 0.07 MPa and hot water boilers with water temperatures over 115 ° C must be registered with the Gosgortekhnadzor bodies. The following documents must be submitted for registration to the inspection: application, boiler passport, certificate of serviceability of the boiler, if it arrived assembled; a certificate of the quality of installation, a drawing of a boiler room, a certificate of compliance of water treatment with a project, a certificate of the presence of feeding devices and their characteristics.
Steam boilers with excess pressure less than or equal to 0.07 MPa, and hot water boilers with a water heating temperature not exceeding 115 ° C, must be located in separate buildings or rooms separated from the production by a firewall (fire wall). Boilers must not be installed under rooms where a large number of people can be found, under warehouses of combustible materials (except those that serve as fuel for the boiler room) and in rooms adjacent to them.
The floors in boiler rooms should be made of non-combustible non-slip materials (concrete).
The distance from the front of the boilers to the opposite wall must be at least 3 m, for boilers for liquid and gas fuels - at least 2 m. The width of the aisles between the boilers, as well as between the boilers and the wall, must be at least 1 m.
In boiler rooms with an area of \u200b\u200bless than 200 m2, one entrance door is arranged that opens outward, with a larger area - at least two in opposite parts of the room. Doors from the boiler room to other rooms should open towards the boiler room, have devices for self-closing and be upholstered with sheet metal on the side of the boiler room.
The boiler room is equipped with natural and artificial ventilation and an emergency lighting system (it is envisaged to use lamps, including rechargeable ones, with an area of \u200b\u200bless than 250 m2, and an autonomous source of energy supply and electric lamps for an area of \u200b\u200bmore than 250 m2).
On the liquid fuel pipelines, shut-off valves are installed in case of an accident or fire, but at least two: one at the burner, and the other outside the boiler house. A fuel tank with a capacity of not more than 0.5 m3 can be installed in the same room as the boilers, but no closer than 3 m from them. Tanks with liquid fuel are located at a distance of at least 12 m from the boiler room and are equipped with a lightning protection device.
In the boiler room there should be: safety instructions for operators posted in a conspicuous place; fire-fighting equipment, which includes two foam fire extinguishers, a box of sand with a capacity of at least 0.5 m3, a shovel, a bucket and a hook.
There must be a plate on the boiler body with the passport data printed on it: name of the manufacturer, serial number, year of manufacture, values \u200b\u200bof working and test pressure, permissible temperature of heating the walls of the boiler.
The person responsible for the safe operation of boilers is the head of the boiler room. In the absence of this position, by order of the enterprise, one of the engineering and technical workers is appointed responsible, who at least once every three years must undergo a knowledge test at the appropriate commission of the enterprise.
Boilers must be serviced by persons at least 18 years of age who have undergone a medical examination, trained according to the appropriate program and have a certificate issued by the qualification commission of the enterprise where the training was conducted. The operators' knowledge is re-checked at least once a year, as well as when switching to servicing other types of boilers.
A logbook should be kept in the boiler room, in which the shift leader signs for the acceptance and delivery of the shift, notes the start and stop times of the boilers, and any faults noticed. It is forbidden to leave the boiler without supervision after the cessation of combustion until the pressure in it drops to atmospheric pressure.
During operation:
· Check the water indicating devices by blowing at least once per shift (usually 2 ... 3 times);
· Control the serviceability of the safety valves at each start-up of the boiler, but in any case at least once per shift (safety valves of steam boilers with an overpressure of up to 1.3 MPa should be triggered when the operating pressure increases by 0.03 MPa);
· Check and seal the manometers at least once a year.
There should be a red line on the dial of the pressure gauge corresponding to the maximum working pressure. It is forbidden to put such a line on the pressure gauge glass, as it can turn and the mark of the maximum allowed pressure will shift in this case. When the pressure is released, the pointer should stop at the zero division of the scale. During operation, it should be within the middle third of the scale. In this case, manometers are installed not lower than an accuracy class of 2.5. The diameter of the pressure gauges must be at least 100 mm with a height of their location up to 2 m and at least 150 mm -2 ... 5 m from the floor level. These devices are installed on the boiler vertically or with an inclination forward to 30 °.
It is not allowed to use manometers if there is no seal or stamp, the verification period is overdue, the arrow of the manometer does not return to the zero mark of the scale when it is turned off, the glass is broken or there is other damage that may affect the correctness of the manometer readings.
The boiler is stopped immediately:
· Upon termination of the operation of water indicating devices or safety valves in an amount exceeding 50% of their total number;
· If the water temperature or steam pressure has risen above the permitted by more than 10% and continues to grow, despite the measures taken (stopping the fuel supply, reducing the draft or blast, increasing the water make-up, etc.);
· When the water level drops below the minimum mark on the gauge glass (in this case, to avoid an explosion, make-up is prohibited) or a rapid drop in its level, despite increased make-up;
· If cracks, bulges, sinks or holes in welds are found in the main elements of the boiler (drum, collector, fire box);
· In case of gas explosion in gas ducts, combustion of fuel particles and soot in them;
If there was a power outage (for boilers with artificial draft);
· If the lining is damaged, threatening a collapse, or the red-hot elements of the boiler glow;
· When detecting malfunctions dangerous for the boiler or service personnel (in the event of knocking, vibration, noise in gas ducts, etc.);
· In case of fire.
During technical examination, the boilers are subjected to:
· Internal inspection and hydraulic test with test pressure during commissioning, after rearrangement or repair of the main elements;
· Internal inspection and hydraulic testing with a working pressure at least once a year, as well as after cleaning or minor repairs that have not affected the main structures;
· Hydraulic test with test pressure at least once every six years.
The test pressure should be at least 150% of the working pressure, but at the same time it should be equal to or more than 0.2 MPa. Maintain the boiler at a certain pressure, usually for 10 ... 15 minutes (but not less than 5 minutes). If no signs of leakage, rupture, "tears", sweating of welded joints or the base metal, and residual deformations are found, then the boiler is deemed fit for use. The examination is carried out by a commission consisting of the head of the production unit, a labor protection specialist and a person responsible for the operation of pressure vessels, or the head of the boiler room. The test results are entered into the boiler passport indicating the date of the next test. Inspection of high-pressure boilers is carried out by an inspector of Gosgortekhnadzor in the presence of a person responsible for safe operation.
