Test system and method for increasing partial stroke activity of main steam valve based on parallel mode

Abstract

The present invention discloses a test system for increasing the partial stroke activity of the main steam valve based on a parallel connection method, comprising a main steam valve and a pressure oil supply pipe, wherein the pressure oil supply pipe is divided into two pipelines, one pipeline is sequentially provided with a switch solenoid valve and a servo valve, and the other pipeline is respectively connected to the servo valve, the lower oil chamber of the main steam valve, the full-stroke movable solenoid valve, and the partial-stroke movable solenoid valve through pipelines. The servo valve is also connected to the upper oil chamber of the main steam valve through a pipeline, and the servo valve is also connected to a pressure oil return pipe through a pipeline, and the pressure oil return pipe is also respectively connected to the full-stroke movable solenoid valve, the partial-stroke movable solenoid valve, and the switch solenoid valve through pipelines. The present invention solves the problem in the prior art that the existing main steam valve formation test system cannot realize the partial stroke activity test, which seriously affects the safety and reliability of the unit. The present invention also discloses an experimental method for increasing the partial stroke activity of the main steam valve based on a parallel connection method.

Description

Technical Field

[0001] The invention belongs to the technical field of steam turbine test devices in thermal power plants, and relates to a test system for increasing the partial stroke activity of a main steam valve based on a parallel connection mode. The invention also relates to a test method for increasing the partial stroke activity of a main steam valve based on a parallel connection mode. Background Art

[0002] Whether the steam turbine valve can be closed quickly and tightly in an emergency is crucial to the safe operation of the unit. During the operation of the unit, it is necessary to ensure that the valve can always be in a reliable and flexible state. Regular valve activity tests as required are important means to prevent valve jams during continuous operation of the unit, to promptly detect defects in the steam turbine valve, and to prevent serious overspeed accidents of the steam turbine.

[0003] According to the relevant requirements of steam turbine technical supervision, power plants with partial stroke test function of steam turbine DEH system are required to conduct valve activity test once a week; power plants with full stroke activity test function of main steam valve and regulating valve are required to conduct full stroke test of steam valve once a month to prevent the valve from getting stuck and causing overspeed accident of the unit when the unit is abnormally shut down. In order to ensure the availability and reliability of main steam valve and regulating valve of high / low pressure cylinder of steam turbine, the valve activity test of steam turbine needs to be carried out regularly, the full stroke activity test of main steam valve and regulating valve is carried out once a month, and the partial stroke activity test of main steam valve and regulating valve is carried out once a week, and the activity range is 10% to 20%.

[0004] After investigation, it was found that many thermal power plants currently only conduct full-stroke activity tests on the main steam valve and regulating valve, but do not conduct partial-stroke activity tests on the main steam valve and regulating valve. The main reason is that the DEH of these power plants only designs the full-stroke test function of the steam valve, but does not design the partial-stroke activity function of the steam valve, which seriously affects the safety and reliability of the unit. Summary of the invention

[0005] The purpose of the present invention is to provide a test system based on parallel mode to increase the partial stroke activity of the main steam valve, which solves the problem that the existing main steam valve forming test system in the prior art cannot realize the partial stroke activity test, which seriously affects the safety and reliability of the unit.

[0006] Another object of the present invention is to provide an experimental method for increasing the partial stroke activity of the main steam valve based on a parallel manner.

[0007] The technical solution adopted by the present invention is to increase the test system of partial stroke activity of the main steam valve in parallel, including a main steam valve and a pressure oil supply pipe, the pressure oil supply pipe is divided into two pipelines, one pipeline is sequentially provided with a switch solenoid valve and a servo valve, and the other pipeline is respectively connected to the servo valve, the lower oil chamber of the main steam valve, the full-stroke activity solenoid valve, and the partial-stroke activity solenoid valve through pipelines. The servo valve is also connected to the upper oil chamber of the main steam valve through a pipeline, and the servo valve is also connected to a pressure return oil pipe through a pipeline, and the pressure return oil pipe is also respectively connected to the full-stroke activity solenoid valve, the partial-stroke activity solenoid valve and the switch solenoid valve through pipelines.

[0008] The first technical solution of the present invention is also characterized in that:

[0009] An oil storage chamber is also connected between the servo valve and the upper oil chamber.

[0010] A valve is also provided on the pressure oil supply pipe.

[0011] The servo valve is a two-stage electro-hydraulic servo valve.

[0012] Both the full-stroke movable solenoid valve and the partial-stroke movable solenoid valve are two-position two-way solenoid valves.

[0013] The switch solenoid valve is a two-position two-way solenoid valve.

[0014] The diameter of the pipe of a partial-stroke movable solenoid valve is two-thirds of the diameter of the pipe of a full-stroke movable solenoid valve.

[0015] Another technical solution adopted by the present invention is a test method for increasing the partial stroke activity of the main steam valve based on a parallel manner. The above-mentioned test system for increasing the partial stroke activity of the main steam valve based on a parallel manner is used to conduct a partial stroke activity test. Specifically, when the main steam valve is opened, the switch solenoid valve is opened, the full-stroke activity solenoid valve and the partial-stroke activity solenoid valve are closed, and the pressurized oil supply in the pressure oil supply pipe is divided into two parts through the valve, one part flows to the switch solenoid valve, and flows to the servo valve through the switch solenoid valve, and the servo valve establishes oil pressure to close the servo valve; the other part of the pressurized oil supply It flows to the servo valve, lower oil chamber and full-stroke movable solenoid valve respectively. Since the full-stroke movable solenoid valve and servo valve are in the closed state, this part of the pressurized oil supply can only flow to the lower oil chamber, so that the valve stem of the main steam valve opens upward, and the pressure oil in the upper oil chamber flows to the oil storage chamber. When the main steam valve is subjected to a partial stroke movable test, the partial stroke movable solenoid valve is opened, and the full-stroke movable solenoid valve is in the closed state. The pressure oil in the lower oil chamber of the main steam valve and the pressurized oil supply flow to the partial stroke movable solenoid valve, and the pressure oil in the oil storage chamber flows to the upper oil chamber to accelerate the valve stem downward, thereby accelerating the closing of the main steam valve.

[0016] The beneficial effects of the present invention are:

[0017] The present invention connects a partial stroke activity test system in parallel with the DEH system for full stroke activity test of the main steam valve and regulating steam valve of a power plant. The partial stroke solenoid valve and pipeline of the partial stroke activity test system are selected with small diameters, so that the oil return time of the partial stroke activity test system is longer, and a longer time margin can be provided for operating the partial stroke activity of the main steam valve, thereby realizing the partial stroke activity test of the main steam valve and the regulating steam valve, which can effectively prevent the valve from being stuck during the continuous operation of the unit, timely discover whether there are defects in the turbine valve, prevent serious overspeed accidents of the turbine, and improve the safety, reliability and economy of the unit operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a test system for increasing the partial stroke activity of a main steam valve based on a parallel connection method according to the present invention.

[0019] In the figure, 1. there is a pressure oil supply pipe, 2. a valve, 3. a switch solenoid valve, 4. a servo valve, 5. a main steam valve, 6. a lower oil chamber, 7. a full-stroke movable solenoid valve, 8. a partial-stroke movable solenoid valve, 9. an upper oil chamber, 10. there is a pressure oil return pipe, 11. an oil storage chamber, and 12. a valve stem. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The present invention is based on a test system for increasing the partial stroke activity of the main steam valve in parallel, and its structure is as follows Figure 1 As shown, it includes a main steam valve 5 and a pressure oil supply pipe 1. The pressure oil supply pipe 1 is divided into two pipelines. A switch solenoid valve 3 and a servo valve 4 are arranged in sequence on one pipeline, and the other pipeline is connected to the servo valve 4, the lower oil chamber 6 of the main steam valve 5, the full-stroke movable solenoid valve 7, and the partial-stroke movable solenoid valve 8 through pipelines. The servo valve 4 is also connected to the upper oil chamber 9 of the main steam valve 5 through a pipeline. The servo valve 4 is also connected to a pressure return oil pipe 10 through a pipeline. The pressure return oil pipe 10 is also connected to the full-stroke movable solenoid valve 7, the partial-stroke movable solenoid valve 8 and the switch solenoid valve 3 through pipelines.

[0022] An oil storage chamber 11 is also connected between the servo valve 4 and the upper oil chamber 9 .

[0023] A valve 2 is also provided on the pressure oil supply pipe 1 .

[0024] The servo valve 4 is a two-stage electro-hydraulic servo valve.

[0025] The full-stroke movable solenoid valve 7 and the partial-stroke movable solenoid valve 8 are both two-position two-way solenoid valves.

[0026] The switch solenoid valve 3 is a two-position two-way solenoid valve.

[0027] The diameter of the pipeline of the partial-stroke movable solenoid valve 8 is two-thirds of the diameter of the pipeline of the full-stroke movable solenoid valve 7.

[0028] The present invention is based on a test method for increasing the partial stroke activity of the main steam valve in a parallel manner. The test system based on increasing the partial stroke activity of the main steam valve in a parallel manner is used. When the partial stroke activity test is performed, specifically: when the main steam valve 5 is opened, the switch solenoid valve 3 is opened, the full-stroke activity solenoid valve 7 and the partial-stroke activity solenoid valve 8 are closed, and the pressurized oil supply in the pressure supply pipe 1 is divided into two parts through the valve 2, one part flows to the switch solenoid valve 3, and flows to the servo valve 4 through the switch solenoid valve 3. The servo valve 4 establishes oil pressure to close the servo valve 4; the other part of the pressurized oil supply flows to the servo valve 4, the lower valve 4 and the lower valve 4 respectively. The oil chamber 6 and the full-stroke movable solenoid valve 7. Since the full-stroke movable solenoid valve 7 and the servo valve 4 are in the closed state, this part of the pressurized oil supply can only flow to the lower oil chamber 6, so that the valve stem 12 of the main steam valve 5 opens upward, and the pressure oil in the upper oil chamber 9 flows to the oil storage chamber 11. When the main steam valve is subjected to a partial stroke movable test, the partial stroke movable solenoid valve 8 is opened, and the full-stroke movable solenoid valve 7 is in the closed state. The pressure oil in the lower oil chamber 6 of the main steam valve 5 and the pressurized oil supply flow to the partial stroke movable solenoid valve 8, and the pressure oil in the oil storage chamber 11 flows to the upper oil chamber 9 to accelerate the valve stem downward, thereby accelerating the closing of the main steam valve.

[0029] The partial stroke solenoid valve and pipeline of the partial stroke movable test system of the present invention are selected with small diameter, so that the time for the pressure oil in the oil chamber below the main steam valve and the pressurized oil supply to flow to the pressurized return oil through the partial stroke movable solenoid valve is prolonged, and a partial stroke movable test of 10% to 20% of the valve stroke can be realized, so that whether the main steam valve is stuck or defective can be discovered in time, which can effectively improve the safety, reliability and economy of the unit operation.

Claims

1. A test method for increasing the partial stroke activity of the main steam valve based on a parallel connection, characterized in that: A test system for increasing the partial stroke activity of a main steam valve in parallel mode is adopted, comprising a main steam valve (5) and a pressure oil supply pipe (1), wherein the pressure oil supply pipe (1) is divided into two pipelines, one pipeline is provided with a switch electromagnetic valve (3) and a servo valve (4) in sequence, and the other pipeline is respectively connected to the servo valve (4), the lower oil chamber (6) of the main steam valve (5), the full stroke movable electromagnetic valve (7), and the partial stroke movable electromagnetic valve (8) through pipelines, the servo valve (4) is also connected to the upper oil chamber (9) of the main steam valve (5) through a pipeline, the servo valve (4) is also connected to a pressure oil return pipe (10) through a pipeline, and the pressure oil return pipe (10) is also respectively connected to the full stroke movable electromagnetic valve (7), the partial stroke movable electromagnetic valve (8), and the switch electromagnetic valve (3) through pipelines; an oil storage chamber (11) is also connected between the servo valve (4) and the upper oil chamber (9); a valve (2) is also provided on the pressure oil supply pipe (1); When conducting a partial stroke activity test, specifically: when the main steam valve (5) is opened, the switch solenoid valve (3) is opened, the full stroke activity solenoid valve (7) and the partial stroke activity solenoid valve (8) are closed, and the pressure oil supply in the pressure oil supply pipe (1) is divided into two parts through the valve (2). One part flows to the switch solenoid valve (3), and flows to the servo valve (4) through the switch solenoid valve (3). The servo valve (4) builds up oil pressure to close the servo valve (4); the other part of the pressure oil supply flows to the servo valve (4), the lower oil chamber (6) and the full stroke activity solenoid valve (7) respectively. Since the full stroke activity solenoid valve (7) When the servo valve (4) and the servo valve (4) are both in the closed state, this part of the pressurized oil can only flow to the lower oil chamber (6), so that the valve stem (12) of the main steam valve (5) opens upward, and at the same time, the pressure oil in the upper oil chamber (9) flows to the oil storage chamber (11). When the main steam valve is subjected to a partial stroke activity test, the partial stroke activity solenoid valve (8) is opened, and the full stroke activity solenoid valve (7) is in the closed state. The pressure oil in the lower oil chamber (6) of the main steam valve (5) and the pressurized oil flow to the partial stroke activity solenoid valve (8), and the pressure oil in the oil storage chamber (11) flows to the upper oil chamber (9) to accelerate the valve stem downward, thereby accelerating the closing of the main steam valve.

2. The test method for increasing the main steam valve partial stroke activity based on parallel mode according to claim 1 is characterized in that: The servo valve (4) is a two-stage electro-hydraulic servo valve.

3. The test method for increasing the main steam valve partial stroke activity based on parallel mode according to claim 1 is characterized in that: The full-stroke movable solenoid valve (7) and the partial-stroke movable solenoid valve (8) are both two-position two-way solenoid valves.

4. The test method for increasing the main steam valve partial stroke activity based on parallel mode according to claim 1 is characterized in that: The switch solenoid valve (3) is a two-position two-way solenoid valve.

5. The test method for increasing the main steam valve partial stroke activity based on parallel mode according to claim 1 is characterized in that: The diameter of the pipeline of the partial-stroke movable solenoid valve (8) is two-thirds of the diameter of the pipeline of the full-stroke movable solenoid valve (7).

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