1. A shaft seal steam supply system of a gas-steam combined cycle heat supply unit is characterized by comprising a high-pressure cylinder (1), a middle-pressure cylinder (2), a low-pressure cylinder (3), a starting boiler (4) and an auxiliary steam header (5);

the steam inlet sides of the high pressure cylinder (1), the intermediate pressure cylinder (2) and the low pressure cylinder (3) are all supplied with steam by a shaft seal steam main pipe, and the shaft seal steam main pipe is provided with a temperature measuring point T₂Forming a shaft seal cavity, wherein residual steam after the sealing of the shaft seal cavity enters a shaft seal steam return main pipe through steam return pipelines respectively, each steam return pipeline is provided with a steam return manual regulating valve, and steam of the shaft seal steam return main pipe goes to a shaft seal heater (30);

and the steam source on the auxiliary steam header (5) is respectively provided by a reheating cold section steam supply auxiliary steam header, a high-pressure main steam drain water supply auxiliary steam header and a starting boiler steam supply auxiliary steam header.

2. The shaft seal steam supply system of the gas-steam combined cycle heat supply unit according to claim 1, wherein the auxiliary steam header (5) is provided with a temperature measuring point T₄The utility model discloses a steam turbine, it is continuous with hydrophobic module (29) through supplementary steam header drainage motorised valve (23) to assist steam header (5) drainage, it loops through supplementary steam supply bearing seal motorised valve (9) and supplementary steam supply bearing seal governing valve (8) and links to each other with the female pipe of bearing seal steam to assist steam header (5) export steam, it sets up parallel pipeline to assist steam supply bearing seal pipeline, it has supplementary steam supply bearing seal bypass motorised valve (10) on the parallel pipeline, it links to each other with hydrophobic module (29) through hydrophobic motorised valve (24) to assist steam supply bearing seal governing valve (8) front line drainage, set up temperature measurement point T before supplementary steam supply bearing seal motorised valve (9) and survey a little valve (29)₁。

3. The shaft seal steam supply system of the gas-steam combined cycle heat supply unit according to claim 1, wherein the boiler steam supply auxiliary steam header comprises a starting boiler (4), and the starting boiler (4) and the auxiliary steam header (5) are connected with a starting boiler steam supply auxiliary steam regulating valve (7) sequentially through a starting boiler steam supply auxiliary steam electric valve (6).

4. The shaft seal steam supply system of the gas-steam combined cycle heat supply unit according to claim 1, wherein the reheat cold section steam supply auxiliary steam header and the high pressure main steam drain supply auxiliary steam header provide a steam source through high pressure main steam, the high pressure main steam is supplied by a waste heat boiler (26), and enters the high pressure cylinder (1) through a high pressure main steam valve (11) and a high pressure main steam regulating valve (12) in sequence, a drain line is arranged in front of the high pressure main steam valve (11), and is connected with a drain module (29) through a high pressure main steam line drain electric valve (13), and the steam source supplied by the waste heat boiler (26) is divided into two paths, and the two paths respectively provide the steam source for the reheat cold section steam supply auxiliary steam header and the high pressure main steam drain supply auxiliary steam header.

5. The gas-steam combined cycle heating unit shaft seal steam supply system of claim 4, wherein the high pressure main steamThe steam supply pipeline of the steam source of the drainage steam supply and auxiliary steam header is led out from the front of a drainage electric valve (13) of a high-pressure main steam pipeline, sequentially passes through a check valve (14) of the high-pressure main steam drainage steam supply and auxiliary steam header, an electric valve (15) of the high-pressure main steam drainage steam supply and auxiliary steam header and a regulating valve (16) of the high-pressure main steam drainage steam supply and auxiliary steam header to be connected with an auxiliary steam header (5), a bypass electric valve (17) is arranged on the pipeline which is connected in parallel, and a temperature measuring point T is arranged in front of the check valve (14) of the high-pressure main steam drainage steam supply and auxiliary steam header₃。

6. The shaft seal steam supply system of the gas-steam combined cycle heat supply unit according to claim 4, wherein a part of the cold reheat section steam supply auxiliary steam header sequentially passes through the cold reheat section steam supply auxiliary steam electric valve (18) and the cold reheat section steam supply auxiliary steam regulating valve (19) to the auxiliary steam header (5), the other part of the cold reheat section steam supply auxiliary steam header passes through the waste heat boiler (27), and the cold reheat section steam supply auxiliary steam header pipeline is connected with the drain module (29) through the drain electric valve (25).

7. The shaft seal steam supply system of the gas-steam combined cycle heat supply unit according to claim 1, wherein the shaft seal steam main pipe is connected with a condenser 28 through a shaft seal overflow regulating valve (20) and a shaft seal overflow electric valve (21), and a bypass electric valve (22) is arranged on a pipeline arranged in parallel.

8. The operation method of a shaft seal steam supply system of a gas-steam combined cycle heat supply unit according to any one of claims 1 to 7, comprising the steps of;

a. in the unit starting stage, the auxiliary steam header (5) is supplied with steam by a starting boiler (4), before steam supply, an auxiliary steam pipeline is fully opened in a drainage mode, a starting boiler steam supply electric valve (6) and a starting boiler steam supply adjusting valve (7) are opened, a high-pressure main steam drainage steam supply auxiliary steam header electric valve (15), a high-pressure main steam drainage steam supply auxiliary steam header adjusting valve (16) and a high-pressure main steam drainage steam supply auxiliary steam header bypass electric valve (17) are closed, and a reheating cold section steam supply auxiliary steam electric valve (18) and a reheating cold section steam supply auxiliary steam adjusting valve (19) are closed; opening an auxiliary steam supply shaft seal electric valve (9) and an auxiliary steam supply shaft seal regulating valve (8), and closing a shaft seal overflow regulating valve (20) and a shaft seal overflow electric valve (21);

b. when the unit is connected to the grid and the load is continuously increased, the cold re-steam comes from the high-pressure cylinder (1) to exhaust steam, so that the metal temperature of the cylinder body can be better matched, the steam source of the auxiliary steam header is gradually changed from the supply of the starting boiler (4) to the supply of the cold re-steam, the starting boiler auxiliary steam supply regulating valve (7) is gradually closed at the moment, and the re-heating cold section steam auxiliary steam supply regulating valve (19) is gradually opened; meanwhile, the shaft seal system gradually turns into a self-sealing state, the auxiliary steam supply shaft seal regulating valve (8) is gradually closed, the shaft seal overflow regulating valve (20) and the shaft seal overflow electric valve (21) are opened after the auxiliary steam supply shaft seal regulating valve (8) is completely closed, the shaft seal system is in the self-sealing state, the opening degree of the auxiliary steam supply shaft seal regulating valve (8) is manually set to be 3% -5%, and the shaft seal overflow regulating valve (20) is utilized to maintain the temperature T of a main pipe of the shaft seal₂And the pressure is stable, and in addition, the auxiliary steam supply shaft seal pipeline drainage electric valve (24) is kept fully opened;

c. when the unit is in a high-load operation state and starts to supply heat, the temperature of cold steam and then steam is continuously reduced along with the continuous increase of the heat supply extraction amount, so that the temperature of the auxiliary steam header (5) and the temperature in front of the auxiliary steam supply shaft seal regulating valve (8) are continuously reduced, and at the moment, the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is closely concerned₁And a shaft seal steam main pipe temperature measuring point T₂(ii) a When auxiliary steam supply shaft seal pipeline temperature measuring point T₁When the value is lower than the preset value of the system, an electric valve (15) of the high-pressure main steam drain water supply auxiliary steam header and an adjusting valve (16) of the high-pressure main steam drain water supply auxiliary steam header are opened, the steam source of the auxiliary steam header is simultaneously provided by cold re-steam and high-pressure main steam, and a temperature measuring point T is observed₃The opening degree of a high-pressure main steam drain water supply auxiliary steam header regulating valve (16) is adjusted by numerical value to control the steam supply temperature of the auxiliary steam supply shaft seal, and the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is used for measuring the temperature₁Temperature measuring point T of auxiliary steam header₄Observing in real time;

d. when the unit is in normal operating condition, if valve breaks down on cold vapor supply auxiliary steam header pipeline or the hydrophobic supply auxiliary steam header pipeline of high pressure main steam, it is comparatively difficult to maintain this moment, if the trouble can't in time be handled, can operate start boiler (4), open start boiler and supply auxiliary steam electric valve (6) and start boiler and supply auxiliary steam governing valve (7), satisfy the required normal temperature of auxiliary steam supply bearing seal.

Background

The gas-steam combined cycle unit has the advantages of high power generation efficiency, good environmental protection performance, quick start, small occupied area, high automation degree and the like, is widely applied in the world and provides various types of power and energy. Most of the energy is used for generating electricity, and the other part of the energy is used for cogeneration or combined cooling heating and power, and the energy is supplied while the energy is supplied for production, living and cold consumption.

The shaft seal system is an important component of the steam turbine, wherein the high-pressure shaft seal is used for preventing steam from leaking out of the cylinder, so that the high efficiency of the steam turbine is ensured; the low-pressure shaft seal has the function of preventing air from leaking into the cylinder and ensuring high-efficiency operation of the unit. The shaft seal system can control the temperature of shaft seal steam according to the temperature of a steam turbine cylinder body and a rotor, so that excessive thermal stress cannot be generated at the shaft seal position of the steam turbine, and the entrance of excessive cooling or overheating steam is prevented.

For the gas-steam combined cycle heat supply unit, partial operation parameters of the unit can be influenced due to the real-time change of the heat supply amount, so that the operation safety and stability of the shaft seal system are influenced. Therefore, for the gas-steam combined cycle heat supply unit, it is necessary to design and optimize the shaft seal steam supply system and ensure the safe, reliable and economic operation of the shaft seal system.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a shaft seal steam supply system of a gas-steam combined cycle heat supply unit and an operation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

a shaft seal steam supply system of a gas-steam combined cycle heat supply unit comprises a high pressure cylinder 1, an intermediate pressure cylinder 2, a low pressure cylinder 3, a starting boiler 4 and an auxiliary steam header 5;

the steam inlet sides of the high pressure cylinder 1, the intermediate pressure cylinder 2 and the low pressure cylinder 3 are all supplied with steam by a shaft seal steam main pipe, and the shaft seal steam main pipe is provided with a temperature measuring point T₂Forming a shaft seal cavity, wherein residual steam after the sealing of the shaft seal cavity enters a shaft seal steam return main pipe through steam return pipelines respectively, each steam return pipeline is provided with a steam return manual regulating valve, and steam of the shaft seal steam return main pipe goes to a shaft seal heater 30;

the steam source on the auxiliary steam header 5 is respectively provided by a reheating cold section steam supply auxiliary steam header, a high-pressure main steam drain water supply auxiliary steam header and a starting boiler steam supply auxiliary steam header;

the auxiliary steam header 5 is provided with a temperature measuring point T₄The drain of the auxiliary steam header 5 is connected with a drain module 29 through an auxiliary steam header drain electric valve 23, the steam at the outlet of the auxiliary steam header 5 is sequentially connected with a main shaft seal steam pipe through an auxiliary steam supply shaft seal electric valve 9 and an auxiliary steam supply shaft seal regulating valve 8, the auxiliary steam supply shaft seal pipeline is provided with a parallel pipeline, an auxiliary steam supply shaft seal bypass electric valve 10 is arranged on the parallel pipeline, the drain of the front pipeline of the auxiliary steam supply shaft seal regulating valve 8 is connected with the drain module 29 through a drain electric valve 24, and a temperature measuring point T is arranged in front of the auxiliary steam supply shaft seal electric valve 9₁。

The boiler steam auxiliary steam supply header comprises a starting boiler 4, wherein the starting boiler 4 and the auxiliary steam header 5 are sequentially connected with a starting boiler auxiliary steam supply electric valve 6 and a starting boiler auxiliary steam supply regulating valve 7.

The steam supply auxiliary steam header of the reheat cold section, the high-pressure main steam drain supply auxiliary steam header provide a steam source through the high-pressure main steam, the high-pressure main steam is supplied by exhaust-heat boiler 26, and loops through high-pressure main steam valve 11 and high-pressure main steam governing valve 12 and gets into high-pressure cylinder 1, sets up the drain line before the high-pressure main steam valve 11, and is continuous with hydrophobic module 29 through the drain motorised valve 13 of high-pressure main steam line, and the steam source that exhaust-heat boiler 26 supplied is two ways, and the steam supply auxiliary steam header of the reheat cold section, the high-pressure main steam drain supply auxiliary steam header provide a steam source respectively.

The steam supply pipeline of the steam source of the high-pressure main steam drainage steam supply auxiliary steam header is led out from the front of the high-pressure main steam pipeline drainage electric valve 13 and sequentially passes through the high-pressure main steam drainage steam supply auxiliary steam header check valveA valve 14, an electric valve 15 of the high-pressure main steam drain water supply auxiliary steam header and a regulating valve 16 of the high-pressure main steam drain water supply auxiliary steam header are connected with the auxiliary steam header 5, a bypass electric valve 17 is arranged on a pipeline which is arranged in parallel, and a temperature measuring point T is arranged in front of a check valve 14 of the high-pressure main steam drain water supply auxiliary steam header₃。

One part of the cold reheat section steam auxiliary steam supply header sequentially passes through the cold reheat section steam auxiliary steam supply electric valve 18 and the cold reheat section steam auxiliary steam supply regulating valve 19 to be removed from the auxiliary steam header 5, the other part of the cold reheat section steam auxiliary steam supply header is removed from the waste heat boiler 27, and the cold reheat section steam auxiliary steam supply header pipeline is drained and connected with the drainage module 29 through the drainage electric valve 25.

The shaft seal steam main pipe is connected with a condenser 28 through a shaft seal overflow regulating valve 20 and a shaft seal overflow electric valve 21, and a bypass electric valve 22 is arranged on a pipeline which is arranged in parallel.

An operation method of a shaft seal steam supply system of a gas-steam combined cycle heat supply unit comprises the following steps;

a. in the unit starting stage, the auxiliary steam header 5 is supplied with steam by a starting boiler 4, before steam supply, an auxiliary steam pipeline is fully opened for draining water, a starting boiler steam supply auxiliary steam electric valve 6 and a starting boiler steam supply auxiliary steam regulating valve 7 are opened, a high-pressure main steam drain water supply auxiliary steam header electric valve 15, a high-pressure main steam drain water supply auxiliary steam header regulating valve 16 and a high-pressure main steam drain water supply auxiliary steam header bypass electric valve 17 are closed, and a reheating cooling section steam supply auxiliary steam electric valve 18 and a reheating cooling section steam supply auxiliary steam regulating valve 19 are closed; opening an auxiliary steam supply shaft seal electric valve 9 and an auxiliary steam supply shaft seal regulating valve 8, and closing a shaft seal overflow regulating valve 20 and a shaft seal overflow electric valve 21;

b. when the unit is connected to the grid and the load is continuously increased, the cold re-steam comes from the high-pressure cylinder 1 to exhaust steam, so that the metal temperature of the cylinder body can be better matched, the steam source of the auxiliary steam header is gradually changed from the supply of the starting boiler 4 to the supply of the cold re-steam, the auxiliary steam supply regulating valve 7 of the starting boiler is gradually closed at the moment, and the auxiliary steam supply regulating valve 19 of the re-heating cold section is gradually opened; meanwhile, the shaft seal system is gradually turned into a self-sealing state, the auxiliary steam supply shaft seal regulating valve 8 is gradually closed, and after the auxiliary steam supply shaft seal regulating valve 8 is completely closed, the shaft seal overflow regulating valve 20 and the shaft seal overflowThe flow electric valve 21 is opened, the shaft seal system is in a self-sealing state, the opening of the shaft seal adjusting valve 8 is 3% -5% by manually setting auxiliary steam, and the shaft seal overflow adjusting valve 20 is utilized to maintain the temperature T of the shaft seal main pipe₂And the pressure is stable, and in addition, the auxiliary steam supply shaft seal pipeline drainage electric valve 24 is kept fully opened;

c. when the unit is in a high-load operation state and starts to supply heat, the temperature of cold steam and then steam is continuously reduced along with the continuous increase of the heat supply extraction amount, so that the temperature of the auxiliary steam header 5 and the temperature in front of the auxiliary steam supply shaft seal regulating valve 8 are continuously reduced, and at the moment, the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is closely concerned₁And a shaft seal steam main pipe temperature measuring point T₂(ii) a When auxiliary steam supply shaft seal pipeline temperature measuring point T₁When the value of the temperature measurement point T is lower than the preset value of the system, the electric valve 15 of the high-pressure main steam drain auxiliary steam supply header and the regulating valve 16 of the high-pressure main steam drain auxiliary steam supply header are opened, at the moment, the steam source of the auxiliary steam header is simultaneously provided by cold re-steam and high-pressure main steam, and the temperature measurement point T is observed₃The steam supply temperature of the auxiliary steam supply shaft seal is controlled by adjusting the opening degree of the high-pressure main steam drain water supply auxiliary steam header adjusting valve 16 by numerical value, and the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is used for measuring the temperature₁Temperature measuring point T of auxiliary steam header₄Observing in real time;

d. when the unit is in normal operating condition, if the valve breaks down on cold vapor supply auxiliary steam header pipeline or the hydrophobic confession auxiliary steam header pipeline of high pressure main steam, it is comparatively difficult to maintain this moment, if the trouble can't in time be handled, can operate start boiler 4, open start boiler and supply auxiliary steam electric valve 6 and start boiler and supply auxiliary steam governing valve 7, satisfy the required normal temperature of auxiliary steam supply bearing seal.

The invention has the beneficial effects that:

the invention provides a steam supply source for an auxiliary steam header of a multi-path gas-steam combined cycle unit, which introduces a high-pressure main steam drain steam supply auxiliary steam header besides a conventional boiler steam starting and cold re-steam supply auxiliary steam header, and effectively solves the problem of unmatched shaft seal steam supply temperature caused by large heat supply air extraction amount of a heat supply unit.

By utilizing the characteristic of high-pressure main steam drainage, the problem of low steam supply temperature of the shaft seal is solved, meanwhile, partial heat of the high-pressure main steam drainage is utilized, the temperature of the drainage condenser is reduced, and the heat economy of the unit is improved.

The operation method of the shaft seal steam supply system not only considers the operation steps and the control strategy of the system when the unit is normally started, but also provides the control strategy of the shaft seal steam supply system when the unit is in various operation states, and provides a solution when a fault occurs. The system control mode is flexible and simple, easy to operate and high in automation degree, and particularly can be operated in an intervention mode at the first time under the fault working condition.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Wherein, 1 is a high pressure cylinder of the steam turbine, 2 is a medium pressure cylinder of the steam turbine, 3 is a low pressure cylinder of the steam turbine, 4 is a starting boiler, 5 is an auxiliary steam header, 6 is a starting boiler auxiliary steam supply electric valve, 7 is a starting boiler auxiliary steam supply adjusting valve, 8 is an auxiliary steam supply shaft seal adjusting valve, 9 is an auxiliary steam supply shaft seal electric valve, 10 is an auxiliary steam supply shaft seal bypass electric valve, 11 is a high pressure main steam valve, 12 is a high pressure main steam adjusting valve, 13 is a high pressure main steam pipeline drainage electric valve, 14 is a high pressure main steam drainage auxiliary steam header check valve, 15 is a high pressure main steam drainage auxiliary steam supply header electric valve, 16 is a high pressure main steam drainage auxiliary steam supply header adjusting valve, 17 is a high pressure main steam drainage auxiliary steam supply header bypass, 18 is a reheat cold section steam supply electric valve, 19 is a reheat cold section steam supply auxiliary steam adjusting valve, 20 is an overflow shaft seal adjusting valve, 21 is an overflow electric valve, 22 is an electric valve for shaft seal overflow bypass, 23 is an electric valve for auxiliary steam header drainage, 24 is an electric valve for auxiliary steam supply shaft seal pipeline drainage, and 25 is an electric valve for cold and re-steam supply auxiliary steam header pipeline drainage.

Meanwhile, a temperature measuring point T is arranged in front of the auxiliary steam supply shaft seal electric valve 9₁The shaft seal steam main pipe is provided with a temperature measuring point T₂A temperature measuring point T is arranged in front of the check valve 14 of the high-pressure main steam drainage and auxiliary steam supply header₃The auxiliary steam header 5 is provided with a temperature measuring point T₄。

26 denotes a waste heat boiler, 27 denotes a waste heat removal boiler, 28 denotes a condenser, 29 denotes a dewatering module, and 30 denotes a shaft seal removal heater.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, the shaft seal steam supply system of the gas-steam combined cycle heat supply unit comprises a high pressure cylinder 1, an intermediate pressure cylinder 2, a low pressure cylinder 3, a starting boiler 4 and an auxiliary steam header 5, wherein steam is supplied to the steam inlet sides of the high pressure cylinder 1, the intermediate pressure cylinder 2 and the low pressure cylinder 3 through a shaft seal steam main pipe, and the shaft seal steam main pipe is provided with a temperature measuring point T₂And after the shaft seal cavity is sealed, the residual steam enters the shaft seal steam return main pipe through a steam return pipeline, each steam return pipeline is provided with a steam return manual regulating valve, and the steam of the shaft seal steam return main pipe goes to a shaft seal heater.

The auxiliary steam header steam source comprises a reheating cold section steam supply auxiliary steam header, a high-pressure main steam drain steam supply auxiliary steam header and a starting boiler steam supply auxiliary steam header, and the auxiliary steam header 5 is provided with a temperature measuring point T₄The auxiliary steam header drain is connected with the drain module through an auxiliary steam header drain electric valve 23, the steam at the outlet of the auxiliary steam header sequentially passes through an auxiliary steam supply shaft seal electric valve 9 and an auxiliary steam supply shaft seal regulating valve 8 to be connected with a shaft seal steam main pipe, the auxiliary steam supply shaft seal pipeline is provided with a parallel pipeline, an auxiliary steam supply shaft seal bypass electric valve 10 is arranged on the parallel pipeline, the auxiliary steam supply shaft seal regulating valve front pipeline drain is connected with the drain module through a drain electric valve 24, and a temperature measuring point T is arranged before the auxiliary steam supply shaft seal electric valve 9₁。

The starting boiler 4 and the auxiliary steam header 5 are connected with the boiler-starting auxiliary steam-supplying electric valve 6 and the boiler-starting auxiliary steam-supplying regulating valve 7 in sequence. One part of the reheating cold section steam passes through the reheating cold section steam auxiliary steam supply electric valve 18 and the reheating cold section steam auxiliary steam supply adjusting valve 19 in sequence to be sent to the auxiliary steam header, the other part is sent to the waste heat boiler, and the reheating cold section steam auxiliary steam supply header pipeline is connected with the drainage module through the drainage electric valve 25.

High-pressure main steam is supplied by a waste heat boiler, and enters the high-pressure cylinder through a high-pressure main steam valve 11 and a high-pressure main steam regulating valve 12 in sequence, a drain pipeline is arranged in front of the high-pressure main steam valve 11, and the drain pipeline is connected with a drain module through a high-pressure main steam pipeline drain electric valve 14. High-pressure main steam drainage auxiliary steam supply header steam sourceThe steam supply pipeline is led out from the front of the high-pressure main steam pipeline drainage electric valve 13, is connected with the auxiliary steam header sequentially through a high-pressure main steam drainage auxiliary steam supply header check valve 14, a high-pressure main steam drainage auxiliary steam supply header electric valve 15 and a high-pressure main steam drainage auxiliary steam supply header regulating valve 16, is provided with a bypass electric valve 17 on the pipeline which is arranged in parallel, and is provided with a temperature measuring point T in front of the high-pressure main steam drainage auxiliary steam supply header check valve 14₃。

The shaft seal steam main pipe is connected with a condenser through a shaft seal overflow regulating valve 20 and a shaft seal overflow electric valve 21, and a bypass electric valve 22 is arranged on a pipeline which is arranged in parallel. .

The operation method of the shaft seal steam supply system of the gas-steam combined cycle heat supply unit comprises the following steps:

a. in one embodiment, when the unit is in a starting stage, the auxiliary steam header 5 is supplied with steam by the starting boiler 4, before steam supply, the auxiliary steam pipeline is drained and fully opened, the starting boiler steam supply auxiliary steam electric valve 6 and the starting boiler steam supply auxiliary steam regulating valve 7 are opened, the high-pressure main steam drain steam supply auxiliary steam header electric valve 15, the regulating valve 16 and the bypass electric valve 17 are closed, and the reheating cold section steam supply auxiliary steam electric valve 18 and the regulating valve 19 are closed; and opening the auxiliary steam supply shaft seal electric valve 9 and the regulating valve 8, and closing the shaft seal overflow regulating valve 20 and the shaft seal overflow electric valve 21.

b. In one embodiment, when the unit is connected to the grid and the load is continuously increased, the cold re-steam is exhausted from the high-pressure cylinder 1, so that the metal temperature of the cylinder body can be better matched, the steam source of the auxiliary steam header is gradually changed from the supply of the starting boiler to the supply of the cold re-steam, the auxiliary steam supply regulating valve 7 of the starting boiler is gradually closed, and the re-heating cold section steam supply auxiliary steam regulating valve 19 is gradually opened; meanwhile, the shaft seal system is gradually turned into a self-sealing state, and the auxiliary steam supply shaft seal regulating valve 8 is gradually closed. When the shaft seal overflow regulating valve 20 and the shaft seal overflow electric valve 21 are opened after the auxiliary steam supply shaft seal regulating valve 8 is fully closed, the shaft seal system is in a self-sealing state, the auxiliary steam supply shaft seal regulating valve 8 is manually arranged at the moment, the opening degree of the shaft seal regulating valve 8 is 3% -5%, and the shaft seal overflow regulating valve 20 is utilized to maintain the temperature T of a main shaft seal pipe₂And the pressure is stable, and in addition, the drain valve 24 before the auxiliary steam supply shaft seal electric valve is kept fully opened.

c. When the unit is in a high-load operation state and starts to supply heat, the temperature of cold steam and then steam is continuously reduced along with the continuous increase of the heat supply extraction amount, so that the temperature of the auxiliary steam header and the front temperature of the auxiliary steam supply shaft seal regulating valve are continuously reduced, and at the moment, the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is closely concerned₁And a shaft seal steam main pipe temperature measuring point T₂. When auxiliary steam supply shaft seal pipeline temperature measuring point T₁When the value of the pressure difference is lower than the preset value of the system, the electric valve 15 and the regulating valve 16 of the high-pressure main steam drain water supply auxiliary steam header are opened, the steam source of the auxiliary steam header is simultaneously provided by cold re-steam and high-pressure main steam, and the temperature measuring point T is observed₃The steam supply temperature of the auxiliary steam supply shaft seal is controlled by adjusting the opening degree of the high-pressure main steam drain water supply auxiliary steam header adjusting valve 16 by numerical value, and the temperature measuring point T of the auxiliary steam supply shaft seal pipeline is used for measuring the temperature₁Temperature measuring point T of auxiliary steam header₄And (5) observing in real time.

d. When the unit is in normal operating condition, if the valve breaks down on cold vapor supply auxiliary steam header pipeline or the hydrophobic confession auxiliary steam header pipeline of high pressure main steam, it is comparatively difficult to maintain this moment, if the trouble can't in time be handled, can operate the start-up boiler, open start-up boiler and supply auxiliary steam electric valve 6 and start-up boiler and supply auxiliary steam governing valve 7, satisfy the required normal temperature of auxiliary vapor supply bearing seal.