CN211464162U - High-temperature high-pressure pipeline flushing system of thermal power generating unit - Google Patents

Abstract

The utility model discloses a thermal power generating unit high temperature high pressure pipeline rinse-system belongs to steam turbine technical field, mainly includes the hydrophobic flash vessel of high temperature high pressure, high-pressure steam collection pipe, middling pressure steam collection pipe, reheat hot section steam trap, reheat cold section steam trap, main vapour steam trap, one section steam trap, cold section to assist vapour header steam trap, control system to and pipeline and valve, the utility model discloses be applied to newly designed unit or overhaul technical improvement unit, can with entire system long-term operation after relevant device installation finishes, need not to disassemble steam turbine and relevant plumbing equipment afterwards, do not do the installation and the dismantlement of any interim pipeline and valve to the system yet, realize main steam pipe, reheat steam cold section pipe, reheat steam hot section pipe, one section steam trap, the flexibility of cold section to high temperature high pressure steam pipeline such as high-assist header pipe and blast.

Description

A high temperature and high pressure pipeline flushing system for thermal power units

technical field

The utility model relates to the technical field of steam turbines, in particular to a high temperature and high pressure pipeline flushing system of a thermal power unit.

Background technique

After the steam turbine generator set has been running for a period of time, it must be overhauled and maintained. The overhaul period is long, and the steam and water pipes will generate impurities and dirt due to the overhaul. After the overhaul is completed, it is necessary to prevent the impurities in the pipeline from entering the steam turbine, causing damage to the turbine blades, and impurities entering the boiler. It will also cause local high temperature pipe burst, the water quality of the soda water circulation system is unqualified, and the condensate water polishing device will also affect the service life due to poor water quality. In the case of a high proportion of clean energy, the frequency of thermal power units participating in peak shaving through shutdowns increases, and there are long shutdowns during wet seasons, and the corrosion of soda and water pipes increases.

Utility model content

In view of the above deficiencies, the utility model provides a high-temperature and high-pressure pipeline flushing system for thermal power units, which can realize high-temperature and high-pressure pipeline flushing of thermal power units.

To achieve the above object, the utility model adopts the following technical solutions:

A high-temperature and high-pressure pipeline flushing system for a thermal power unit, comprising a high-temperature and high-pressure drainage expansion vessel, a high-pressure steam collecting pipe, a medium-pressure steam collecting pipe, a reheating hot section draining tank, a reheating cold section draining tank, a main steam draining tank, and a first-stage extraction tank. Steam drain tank, cold section to auxiliary steam header extraction steam drain tank and control system;

The high temperature and high pressure hydrophobic expansion container is provided with a desuperheating water spray device, the high pressure steam collecting pipe and the medium pressure steam collecting pipe are respectively connected to the high temperature and high pressure hydrophobic expansion container, and the top of the high temperature and high pressure hydrophobic expansion container is provided with a pair of countermeasures. An air exhaust pipe, an air exhaust valve is installed on the air exhaust pipe, a sewage discharge pipe is installed at the bottom of the high temperature and high pressure hydrophobic expansion container, and a sewage discharge valve is installed on the sewage pipe, and the air exhaust valve is installed and the blowdown valve are respectively connected with the control system;

The reheat hot section drain tank, the reheat cold section drain tank and the main steam drain tank are respectively connected with the high-pressure steam collector through pipes, and the reheat hot section drain tank, the reheat cold section drain tank and the main steam drain tank Drainage pneumatic valves are respectively installed on the pipes connecting the tank and the high pressure steam collector, and the drainage pneumatic valves are respectively connected with the control system;

The first-stage extraction steam tank and the cold section to the auxiliary steam header are respectively connected to the medium-pressure steam header through pipes, and the first-stage extraction steam tank and the cold section to the auxiliary steam header are connected to the auxiliary steam header. Drainage pneumatic valves are respectively installed on the pipelines connected with the medium pressure steam header, and the drainage pneumatic valves are respectively connected with the control system.

Further, a liquid level measuring device is installed on the reheating hot section draining tank, the reheating cold section draining tank, the main steam draining tank, the first-stage extraction steam draining tank and the extraction steam draining tank from the cold section to the auxiliary steam header, respectively, The liquid level measuring devices are respectively connected with the control system.

Further, the pipes connecting the reheat hot section drain tank, the reheat cold section drain tank and the main steam drain tank with the high-pressure steam collecting pipe and the connection port of the high-pressure steam collecting pipe are gradually moved away from the high-pressure steam collecting pipe. The arrangement of the high-temperature and high-pressure drainage expansion vessels; the connection port of the first-stage steam extraction and drainage tank and the cold section to the auxiliary steam header extraction steam tank and the medium-pressure steam header and the connection port of the medium-pressure steam header are in the middle-pressure The steam collecting pipes are arranged gradually close to the high temperature and high pressure hydrophobic expansion vessel.

Further, the high temperature and high pressure hydrophobic expansion container is provided with a temperature measurement device for the hydrophobic expansion container, and the temperature measurement device for the hydrophobic expansion container is connected with the control system.

Further, the desuperheating water spray device is connected to an external water source through a condensed water desuperheating water inlet pipe, and a desuperheating water regulating valve is installed on the condensed water desuperheating water inlet pipe, and the desuperheating water regulating valve is connected with the control system.

Further, the bottom of the high temperature and high pressure hydrophobic expansion vessel is provided with a working medium recovery pipe, and a working medium recovery valve is installed on the working medium recovery pipe, and the working medium recovery valve is connected with the control system.

Further, shut-off valves are respectively installed on both sides of the drainage pneumatic valve on the pipes connecting the reheat hot section drain tank, the reheat cold section drain tank and the main steam drain tank with the high-pressure steam collector; Stop valves are respectively installed on both sides of the steam trap pneumatic valve on the pipes connecting the steam drain tank and the cold section to the auxiliary steam header extraction steam drain tank and the medium pressure steam header.

Further, a muffler is installed on the air-to-air exhaust pipe.

Compared with the prior art, the beneficial effects of the present utility model are:

1. The utility model is applied to newly designed units or overhauled technical units. After the installation of the related devices, it can run with the entire system for a long time. After that, there is no need to disassemble the steam turbine and its related piping equipment, and no temporary piping and equipment are required for the system. The installation and disassembly of the valve can realize flexible purging of high temperature and high pressure steam pipes such as the main steam pipe, the reheat steam cold section pipe, the reheat steam hot section pipe, the first section steam extraction pipe, the cold section to the high auxiliary header pipe, etc. quality recycling;

2. Stop valves are installed at the front and rear of the steam trap pneumatic valve of the high-pressure steam source. The opening of the stop valve can be opened larger or smaller as required. During normal drainage, it can prevent the high-temperature steam discharged into the condenser due to excessive steam flow and cause heat. At the same time, it also reduces the energy loss caused by the excessive load of the condenser caused by the excessive amount of steam flowing into the condenser;

3. A drain tank is installed to realize the function of automatic discharge of accumulated water in the pipeline, to prevent the water inflow of the steam turbine from causing water impact, and it is suitable for the effective protection of the steam turbine under the condition of sudden drop in steam temperature during the start-up and operation of the unit;

4. A silencer is installed on the air exhaust pipe on the high temperature and high pressure drainage expansion vessel to reduce the noise pollution to the environment during the start-up process of the unit.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present utility model more clearly, the accompanying drawings required to be used in the description of the embodiments will be briefly introduced below.

Fig. 1 is the structural representation of the utility model;

FIG. 2 is a schematic diagram of the implementation of the utility model.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

1 and 2, the present utility model provides a high-temperature and high-pressure pipeline flushing system for a thermal power unit, which mainly includes a high-temperature and high-pressure drainage expansion vessel 36, a high-pressure steam collecting pipe 25, a medium-pressure steam collecting pipe 32, and a reheating hot section drain Tank 1, reheat cold section drain tank 7, main steam drain tank 13, first stage extraction steam drain tank 19, cold section to auxiliary steam header extraction steam drain tank 26 and control system 45.

There is a desuperheating water spray device 37 in the high temperature and high pressure drain expansion container 36, and the desuperheating water spray device 37 realizes the cooling and pressure reduction effect of the high temperature and high pressure steam. The external water source is connected, and a desuperheating water regulating valve 38 is installed on the condensed water desuperheating water inlet pipe 39. The desuperheating water regulating valve 38 is connected with the control system 45, and the control system 45 controls the desuperheating water regulating valve 38 to control the desuperheating water regulating valve. 38 degrees of opening. The OVATION distributed control system can be used when the control system 45 is implemented. The high temperature and high pressure hydrophobic expansion container 36 is provided with a hydrophobic expansion container temperature measuring device 44 , the hydrophobic expansion container temperature measurement device 44 is used for measuring the temperature in the high temperature and high pressure hydrophobic expansion container 36 , and the hydrophobic expansion container temperature measuring device 44 is connected with the control system 45 . , the control system 45 collects the temperature signal of the temperature measuring device 44 of the hydrophobic expansion vessel. The temperature measuring device 44 of the hydrophobic expansion vessel can use an E-type thermocouple. The top of the high temperature and high pressure hydrophobic expansion container 36 is provided with an air exhaust pipe 34 , and an air exhaust valve 35 is installed on the air exhaust pipe 34 . The bottom of the high temperature and high pressure hydrophobic expansion vessel 36 is provided with a sewage pipe 42 , and a sewage valve 43 is installed on the sewage pipe 42 . The bottom of the high temperature and high pressure hydrophobic expansion vessel 36 is provided with a working medium recovery pipe 41, a working medium recovery valve 40 is installed on the working medium recovery pipe 41, and one end of the working medium recovery pipe 41 is connected to the condenser of the steam turbine. After the high temperature and high pressure steam is cooled, it is discharged into the trench through the sewage valve 43 and the sewage pipe 42. After the water quality is qualified, the working fluid recovery valve 40 is opened and flows into the condenser through the working fluid recovery pipe 41 for recycling, so as to realize the working fluid recovery. The working fluid recovery valve 40 , the air exhaust valve 35 and the blowdown valve 43 are respectively connected with the control system 45 , and the control system 45 controls the working fluid recovery valve 40 , the air exhaust valve 35 and the blowdown valve 43 to control the working fluid The openings of the recovery valve 40 , the air exhaust valve 35 and the blowdown valve 43 . The desuperheating water regulating valve 38, the working medium recovery valve 40, and the drain valve 43 use electric actuators, and have the functions of full opening, full closing, and intermediate stroke adjustment. The air exhaust valve 35 uses compressed air as the power source, and has the functions of fully open and fully closed.

The high-pressure steam header 25 and the medium-pressure steam header 32 are respectively connected to the high-temperature and high-pressure hydrophobic expansion vessel 36. The high-pressure steam header 25 and the medium-pressure steam header 32 are respectively a structure with one end sealed and one end open, and the open end is connected to the high temperature and high pressure. Inside the hydrophobic expansion vessel 36 .

The reheat hot section drain tank 1, the reheat cold section drain tank 7 and the main steam drain tank 13 are respectively connected to the high pressure steam header 25 through pipes. The reheat hot section drain tank 1, the reheat cold section drain tank 7 and the main steam drain tank 13 The pipes connecting the steam-drain tank 13 and the high-pressure steam collecting pipe 25 are respectively installed with steam-drain pneumatic valves, which are respectively connected with the control system 45 . The first-stage extraction steam tank 19 and the cold section to the auxiliary steam header extraction steam tank 26 are respectively connected to the medium pressure steam header 32 through pipelines, and the first-stage extraction steam tank 19 and the cold section to the auxiliary steam header. 26 The pipes connected with the medium-pressure steam collecting pipe 32 are respectively installed with steam trapping pneumatic valves, and the steam trapping pneumatic valves are respectively connected with the control system 45 . Specifically, the reheat hot section drain tank 1 is connected to the high-pressure steam header 25 through the reheat hot section drain pipe 3, and the reheat hot section drain pipe 3 is provided with a reheat hot section drain pneumatic valve 5. The first stop valve 4 and the second stop valve 6 are installed on both sides of the reheating hot section steam trapping pneumatic valve 5 on the drain pipe 3; 25 is connected, the reheat and cold section drain pipe 9 is installed with a reheat and cold section drain pneumatic valve 11, and the reheat and cold section drain pipe 9 is installed with a third stop valve 10 on both sides of the reheat and cold section drain valve 11. and the fourth shut-off valve 12; the main steam drain tank 13 is connected with the high pressure steam collecting pipe 25 through the main steam drain pipe 15, the main steam drain pipe 15 is installed with a main steam drain pneumatic valve 17, and the main steam drain pipe 15 is pneumatically connected to the main steam drain pipe 15. A fifth stop valve 16 and a sixth stop valve 18 are installed on both sides of the valve 17; a section of the extraction steam trap 19 is connected to the medium pressure steam header 32 through a section of the steam extraction and drainage pipe 21, and a section of the steam extraction and drainage pipe 21 is installed on it. Extraction steam trap pneumatic valve 23, a seventh stop valve 22 and an eighth stop valve 24 are installed on both sides of the first extraction steam trap pneumatic valve 23 on the first section of the extraction steam trap pipe 21; the cold section to the auxiliary steam header extraction steam drain tank 26 Through the cold section to the auxiliary steam header extraction steam drain pipe 28 is connected with the medium pressure steam header 32, the cold section to the auxiliary steam header steam extraction steam pipe 28 is installed with the cold section to the auxiliary steam header steam extraction and drainage pneumatic valve 30, A ninth cut-off valve 29 and a tenth cut-off valve 31 are installed on both sides of the extraction steam trapping pipe 28 from the cold section to the auxiliary steam header on both sides of the pneumatic valve 30 for the extraction steam from the cold section to the auxiliary steam header. Reheat hot section steam trap pneumatic valve 5, reheat cold section steam trap pneumatic valve 11, main steam steam trap pneumatic valve 17, first stage extraction steam trap pneumatic valve 23 and cold section to auxiliary steam header extraction steam trap pneumatic valve 30 are respectively connected with the control system 45 are connected, and the control system 45 respectively controls them to control their opening degrees.

Reheat hot section steam trap pneumatic valve 5, reheat cold section steam trap pneumatic valve 11, main steam steam trap pneumatic valve 17, first stage extraction steam trap pneumatic valve 23 and cold section to auxiliary steam header extraction steam trap pneumatic valve 30 are installed with cut-off before and after. The opening of the valve and the globe valve can be opened larger or smaller according to the needs, which can prevent the high-temperature steam discharged into the condenser and cause heat loss due to excessive steam flow during normal drainage, and also reduce the amount of steam flowing into the condenser. Excessive energy loss caused by excessive condenser load. And when the reheat hot section steam trap pneumatic valve 5, the reheat cold section steam trap pneumatic valve 11, the main steam steam trap pneumatic valve 17, the first stage extraction steam trap pneumatic valve 23 and the cold section to auxiliary steam header extraction steam trap pneumatic valve 30 are damaged At the time, the stop valve on the corresponding pipeline can be closed, which can not only repair and replace the pneumatic valve of each trap in time, but also prevent the high-temperature steam from other normal pipelines from going out from the position of the damaged trap pneumatic valve.

The reheat hot section drain tank 1, the reheat cold section drain tank 7, the main steam drain tank 13, the first stage extraction steam drain tank 19 and the cold section to auxiliary steam header extraction steam drain tank 26 are respectively equipped with liquid level measuring devices. The liquid level measuring devices are respectively connected with the control system 45 , and the liquid level measuring devices are used to measure the liquid level in the drain tank and transmit the liquid level information to the control system 45 . Specifically, the reheat hot section drain tank 1 is installed with a reheat hot section drain tank liquid level measuring device 2, the reheat cold section drain tank 7 is installed with a reheat cold section drain tank liquid level measurement device 8, and the main steam drain Tank 13 is installed with a main steam drain tank liquid level measuring device 14, a first stage extraction steam drain tank 19 is installed with a first stage extraction steam drain tank liquid level measurement device 20, and a cold section to the auxiliary steam header is installed on the extraction steam drain tank 26. Cold section to auxiliary steam header extraction steam drain tank liquid level measuring device 27. Reheat hot section drain tank liquid level measurement device 2, reheat cold section drain tank liquid level measurement device 8, main steam drain tank liquid level measurement device 14, first-stage extraction steam drain tank liquid level measurement device 20 and cold section to auxiliary steam The header steam extraction and drain tank liquid level measurement devices 27 are respectively connected to the control system 45, and the control system 45 collects the reheat hot section drain tank liquid level measurement device 2, the reheat cold section drain tank liquid level measurement device 8, and the main steam drain If the control system 45 collects the signals from the tank liquid level measuring device 14, the first stage extraction steam drain tank liquid level measuring device 20, and the cold section to the auxiliary steam header extraction steam drain tank liquid level measuring device 27, if the control system 45 collects one or more of them If the signal of the liquid level measuring device is high, the opening degree of the corresponding steam trap pneumatic valve can be controlled accordingly, and the opening degree can be increased to prevent the liquid level of one or several steam traps from being too high.

The reheat hot section drain tank 1, the reheat cold section drain tank 7 and the main steam drain tank 13 are connected to the high-pressure steam header 25 and the connection port of the high-pressure steam header 25 is gradually away from the high-pressure steam header 25. The arrangement of the high temperature and high pressure hydrophobic expansion vessel 36 . The pipes connecting the first stage extraction steam drain tank 19 and the cold section to the auxiliary steam header extraction steam drain tank 26 and the medium pressure steam header 32 and the connection port of the medium pressure steam header 32 are gradually formed on the medium pressure steam header 32. The arrangement near the high temperature and high pressure hydrophobic expansion vessel 36 . In this preferred embodiment, specifically, on the high-pressure steam collecting pipe 25, the connection port of the reheating hot section drain pipe 3 and the high-pressure steam collecting pipe 25 is closest to the high temperature and high pressure draining expansion vessel 36, and the reheating cold section draining pipe 9. The connection port with the high-pressure steam header 25 is second, and the connection port between the main steam drain pipe 15 and the high-pressure steam header 25 is the farthest from the high-temperature and high-pressure drain expansion vessel 36; The distance between the connection port of the water pipe 21 and the medium pressure steam header 32 and the high temperature and high pressure drain expansion vessel 36 is farther than the distance between the connection port of the extraction steam drain pipe 28 and the medium pressure steam header 32 from the cold section to the auxiliary steam header and the high temperature and high pressure drain expansion. distance from the device 36. The reason for this setting is that, in the implementation, on the high-pressure steam header 25, the drain pressure from the main steam drain pipe 15 is the largest, followed by the reheating cold section drain pipe 9, and the reheating hot section drain pipe 3 is the smallest. Therefore, the connection port of the main steam drain pipe 15 and the high-pressure steam collector pipe 25 is located at the farthest point, and the connection port of the reheat hot section drain pipe 3 and the high-pressure steam collector pipe 25 is located at the nearest place, which can ensure the reheat hot section drain pipe. 3. The reheating cold section drain pipe 9 and the main steam drain pipe 15 smoothly and smoothly enter the high-temperature and high-pressure drain expansion vessel 36 through the high-pressure steam header 25; The drain pressure coming from the cold section is larger than the drain pressure from the cold section to the auxiliary steam header extraction steam pipe 28, so this setting can ensure that the first section of the extraction steam pipe 21 and the cold section to the auxiliary steam header. , smoothly enter the high temperature and high pressure hydrophobic expansion container 36 through the medium pressure steam header 32 .

A muffler 33 is installed on the anti-air exhaust pipe 34. After the anti-air exhaust valve 35 is opened, the anti-air exhaust pipe 34 discharges the decompressed high-temperature steam generated in the high-temperature and high-pressure hydrophobic expansion container 36 through the muffler 33 to the atmosphere. , setting the muffler 33 can reduce the environmental noise pollution during the start-up process of the unit.

Among the commonly used steam turbines, please refer to Fig. 2, the steam turbine mainly includes a medium pressure combined steam valve 46, a reheating section steam pipe 47, a main steam pipe 48, a main steam valve 49, a high pressure regulating valve 50, and a first high exhaust backstop. Valve 51, second high-exhaust check valve 52, high-pressure cylinder exhaust steam manifold 53, steam pipe 54 between high-by-pass valve and reheat cold-section drain tank, high-by-pass valve 55, first-stage extraction steam to high-pressure heater steam pipe 56. High pressure heater inlet steam electric valve 57, high pressure heater 58, steam extraction steam pipe 59 from cold section to auxiliary steam header, steam inlet regulating valve 60 and auxiliary steam header 61 from cold section to auxiliary steam header. During implementation, please refer to FIG. 2, the reheat hot section drain tank 1 is installed on the reheat hot section steam pipe 47 in front of the medium pressure combined valve 46 and communicates with the reheat hot section steam pipe 47; the reheat cold section drains The tank 7 is installed on the high-pressure cylinder exhaust manifold 53 near the first high-row check valve 51 and the second high-row check valve 52 and communicates with the high-pressure cylinder exhaust manifold 53; the main steam drain tank 13 is being installed The main steam pipe 48 in front of the main steam valve 49 is connected to the main steam pipe 48; a section of extraction steam drain tank 19 is installed on the pipe in front of the high-pressure heater inlet steam electric valve 57 and communicated with the pipe; the cold section The extraction steam drain tank 26 to the auxiliary steam header is installed on the pipeline from the cold section to the auxiliary steam header before the steam inlet regulating valve 60 and communicates with the pipeline.

In addition, the arrow direction in FIG. 1 and FIG. 2 is the direction of the fluid in each pipe.

Taking a 300MW unit project as an example, the following is a specific realization process of the utility model:

Before implementation, with reference to FIG. 1 and FIG. 2 and the above-mentioned preferred implementation examples of the present application, the high-temperature and high-pressure pipeline flushing system of the thermal power unit is integrated into the steam turbine.

The boiler is heated and boosted to run, the steam turbine is in shutdown state, close the working medium recovery valve 40, the high-pressure heater inlet steam valve 57, the cold section to the auxiliary steam header inlet steam regulating valve 60, and open the high bypass valve 55 to the required opening to Maintain the steam-water cycle operation of the generator set, and open all shut-off valves (i.e. the first shut-off valve 4, the second shut-off valve 6, the third shut-off valve 10, the fourth shut-off valve 12, the fifth shut-off valve 16, the sixth shut-off valve 18, the The seventh stop valve 22, the eighth stop valve 24, the ninth stop valve 29 and the tenth stop valve 31), open the air exhaust valve 35, open the desuperheating water regulating valve 38, and open the blowdown valve 43. When the main steam pressure and reheating When the steam pressure reaches the requirement, fully open the corresponding steam trap pneumatic valve (i.e. main steam steam trap pneumatic valve 17, reheat hot section steam trap valve 5, reheat cold section steam trap valve 11, first-stage extraction steam trap pneumatic valve 23, cold section steam valve 23) To the auxiliary steam header extraction steam drain pneumatic valve 30) to realize that the drain from the boiler is respectively flushed to the main steam pipe, the hot section of the reheat pipe, the cold section of the reheat pipe, the first section of the steam extraction pipe, the cold section to the high auxiliary pipe, and then Then through the main steam drain pipe 15, the reheat hot section drain pipe 3 and the reheat cold section drain pipe 9 through the high pressure steam header 25 into the high temperature and high pressure drain expansion vessel 36, and through the first steam extraction and drain pipe 21 and the cold section to the auxiliary steam connection. The box extraction steam drain pipe 28 enters the high temperature and high pressure drain expansion container 36 through the medium pressure steam header 32, and the drain enters the high temperature and high pressure drainage expansion container 36, and is decompressed under the auxiliary action of the desuperheating water spray device 37, wherein the steam passes through The air exhaust pipe 34 is discharged to the atmosphere after the noise is reduced by the muffler 33, and the liquid water is discharged to the drainage ditch outside the system through the sewage pipe 42;

Through the sampling of drainage ditch water, the working fluid recovery valve 40 is opened after the water quality meets the recycling conditions, and the sewage valve 43 and the air exhaust valve 35 are closed at the same time, and the condensate desuperheating water and the drain are recycled;

When the steam turbine starts and runs with load, when the load is less than 10% of the rated load, the reheating hot section steam trap pneumatic valve 5, the reheat cold section steam trap pneumatic valve 11, the main steam steam trap pneumatic valve 17, and the first-stage extraction steam trap pneumatic valve 23 are still maintained. . The air extraction steam valve 30 from the cold section to the auxiliary steam header is opened, and its opening is adjusted according to the premise of ensuring that there is no alarm signal from the liquid level measuring device in each steam drainage tank (the alarm will be alarmed when the preset water level exceeds the set threshold);

When the steam turbine has a load > 11% of the rated load, close the reheat hot section steam trap pneumatic valve 5, the reheat cold section steam trap pneumatic valve 11, the main steam steam trap pneumatic valve 17, the first stage extraction steam trap pneumatic valve 23, and the cold section to the auxiliary steam. The header steam extraction and drain pneumatic valve 30 closes the desuperheating water regulating valve 38;

When the load of the steam turbine is greater than 11% of the rated load, the main steam temperature is less than 450°C and the rate of change is greater than 50°C/min or the reheat steam temperature is less than 450°C and the rate of change is greater than 50°C/min, and the interlock will open the desuperheating water adjustment. Valve 38, interlock fully open main steam drain pneumatic valve 17 and reheat hot section drain pneumatic valve 5;

When the load of the steam turbine is greater than 11% of the rated load, and an alarm signal appears on the liquid level of the drain tank, the control system 45 automatically opens the desuperheating water regulating valve 38, and when:

(1) When the main steam drain tank liquid level measuring device 14 sends an alarm signal, the main steam drain pneumatic valve 17 is interlocked to fully open the main steam drain pneumatic valve 17; if there is no high switch signal for 10 seconds, the main steam drain pneumatic valve 17 is interlocked and closed;

(2) When the liquid level measuring device 2 of the reheat hot section drain tank sends an alarm signal, the interlock fully opens the reheat hot section drainage pneumatic valve 5; if there is no high switch signal for 10 seconds, the interlock closes the reheat hot section drainage pneumatic adjustment 5 ;

(3) When the liquid level measuring device 8 of the reheat and cold section drainage tank sends an alarm signal, the interlock fully opens the reheat and cold section drainage pneumatic valve 11; if there is no high switch signal for 10 seconds, the interlock closes the reheat and cold section drainage pneumatic valve 11 ;

(4) When the liquid level measuring device 20 of the first-stage extraction and drain tank sends an alarm signal, the interlock will fully open the liquid-level measuring device 20 of the first-stage extraction and drain tank; if there is no high switch signal for 10 seconds, the interlock will close the liquid level of the first-stage extraction and drain tank. measuring device 20;

(5) When the liquid level measuring device 27 of the extraction steam drain tank from the cold section to the auxiliary steam header sends an alarm signal, the interlock fully opens the cold section to the auxiliary steam header extraction steam and drain pneumatic valve 30; if there is no high switch signal for 10 seconds, the connection Lock and close the pneumatic valve 30 of the extraction steam drain from the cold section to the auxiliary steam header;

After the desuperheating water regulating valve 38 is fully opened, the opening degree of the desuperheating water regulating valve 38 is adjusted according to the target that the measured value of the water-repellent expansion vessel temperature measuring device 44 is less than 80°C.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field of the present invention can easily think of changes within the technical scope disclosed by the present invention. Or replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (8)

1. A high-temperature high-pressure pipeline flushing system of a thermal power generating unit is characterized by comprising a high-temperature high-pressure drain flash tank (36), a high-pressure steam collecting pipe (25), a medium-pressure steam collecting pipe (32), a reheating hot section drain tank (1), a reheating cold section drain tank (7), a main steam drain tank (13), a section of steam extraction drain tank (19), a cold section-to-auxiliary steam header steam extraction drain tank (26) and a control system (45);

a desuperheating water spray device (37) is arranged in the high-temperature and high-pressure drainage flash tank (36), the high-pressure steam collecting pipe (25) and the medium-pressure steam collecting pipe (32) are respectively communicated with the high-temperature and high-pressure drainage flash tank (36), an air exhaust pipe (34) is arranged at the top of the high-temperature and high-pressure drainage flash tank (36), an air exhaust valve (35) is installed on the air exhaust pipe (34), a drain pipe (42) is arranged at the bottom of the high-temperature and high-pressure drainage flash tank (36), a drain valve (43) is installed on the drain pipe (42), and the air exhaust valve (35) and the drain valve (43) are respectively connected with a control system (45);

the reheating hot section drain tank (1), the reheating cold section drain tank (7) and the main steam drain tank (13) are respectively connected with a high-pressure steam collecting pipe (25) through pipelines, and the reheating hot section drain tank (1), the reheating cold section drain tank (7) and the main steam drain tank (13) are respectively provided with a hydrophobic pneumatic valve on the pipeline connected with the high-pressure steam collecting pipe (25), and the hydrophobic pneumatic valves are respectively connected with a control system (45);

one section steam extraction steam trap (19) and cold section to assist vapour header steam extraction steam trap (26) are connected with middling pressure collection steam pipe (32) through the pipeline respectively, install hydrophobic pneumatic valve respectively on one section steam extraction steam trap (19) and cold section to the pipeline that assist vapour header steam extraction steam trap (26) and middling pressure collection steam pipe (32) are connected, hydrophobic pneumatic valve is connected with control system (45) respectively.

2. The thermal power generating unit high-temperature high-pressure pipeline flushing system as recited in claim 1, wherein a working medium recovery pipe (41) is arranged at the bottom of the high-temperature high-pressure drain flash tank (36), a working medium recovery valve (40) is mounted on the working medium recovery pipe (41), and the working medium recovery valve (40) is connected with a control system (45).

3. The high-temperature and high-pressure pipeline flushing system for the thermal power generating unit according to claim 1, wherein liquid level measuring devices are respectively installed on the reheating hot section steam trap (1), the reheating cold section steam trap (7), the main steam trap (13), the first steam extraction steam trap (19) and the steam extraction steam trap (26) from the cold section to the auxiliary steam header, and the liquid level measuring devices are respectively connected with a control system (45).

4. The high-temperature and high-pressure pipeline flushing system of the thermal power generating unit according to claim 1, wherein connecting ports of pipelines of the reheating hot-section steam trap (1), the reheating cold-section steam trap (7), the main steam trap (13) and the high-pressure steam collecting pipe (25) are arranged on the high-pressure steam collecting pipe (25) and gradually far away from the high-temperature and high-pressure drain flash tank (36); the pipeline of the first-section steam extraction steam trap (19) and the pipeline of the cold-section steam extraction steam trap (26) to the auxiliary steam header and the medium-pressure steam collecting pipe (32) and the connection port of the medium-pressure steam collecting pipe (32) are arranged on the medium-pressure steam collecting pipe (32) and are gradually close to the high-temperature high-pressure drainage flash tank (36).

5. The thermal power generating unit high-temperature high-pressure pipeline flushing system as claimed in claim 1, wherein a drain flash tank temperature measuring device (44) is arranged on the high-temperature high-pressure drain flash tank (36), and the drain flash tank temperature measuring device (44) is connected with a control system (45).

6. The thermal power generating unit high-temperature high-pressure pipeline flushing system as claimed in claim 1, wherein the desuperheating water spraying device (37) is connected with an external water source through a condensed water desuperheating water inlet pipe (39), a desuperheating water adjusting valve (38) is installed on the condensed water desuperheating water inlet pipe (39), and the desuperheating water adjusting valve (38) is connected with a control system (45).

7. The high-temperature and high-pressure pipeline flushing system for the thermal power generating unit according to claim 2, wherein stop valves are respectively arranged on two sides of the hydrophobic pneumatic valve on pipelines connected with the reheat hot section drain tank (1), the reheat cold section drain tank (7) and the main steam drain tank (13) and the high-pressure steam collecting pipe (25); stop valves are respectively arranged on two sides of the hydrophobic pneumatic valve on pipelines connected with the first section steam extraction drain tank (19), the cold section steam extraction drain tank (26) of the auxiliary steam header and the medium pressure steam collecting pipe (32).

8. The thermal power generating unit high-temperature high-pressure pipeline flushing system as recited in claim 1, characterized in that a silencer (33) is mounted on the air exhaust pipe (34).

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