Method and system suitable for valve activity test in operation of 1000MW unit

Abstract

The invention relates to the technical field of mechanical engineering and generator sets, in particular to a valve activity test method and system suitable for 1000MW unit operation, and the method comprises the following steps: a single-side main valve activity test step: controlling a single-side main valve to be gradually closed from a full-open position; when the opening and closing degree of the single-side main throttle valve is greater than a first preset opening and closing degree, or when the full-open feedback time of the single-side main throttle valve exceeds a first preset feedback time, the single-side main throttle valve is controlled to be opened to a full-open position, and a single-side main throttle valve activity test is completed; and a single-side medium-voltage control valve activity test step: controlling the single-side medium-voltage control valve to be gradually closed to a second preset opening and closing degree from the full-open position, and when the second preset opening and closing degree of the single-side medium-voltage control valve exceeds the preset holding time, or when the full-open feedback time of the single-side medium-voltage control valve exceeds the second preset feedback time, the single-side medium-voltage control valve is controlled to be opened to the full-open position, and the single-side medium-voltage control valve activity test is completed.

Description

Technical Field

[0001] The present invention relates to the technical fields of mechanical engineering and generator sets, and particularly relates to a method and system for a steam valve activity test during the operation of a 1000MW unit. Background Art

[0002] A full-stroke test of the steam valve is carried out once a month, but during the activity test, it is easy to occur the situation of seizure and trip. As the heart of a thermal power plant, the steam turbine is of utmost importance for safety, which involves the reliability of important protection and control devices of the unit. It is necessary to strictly follow the relevant requirements of technical supervision, thoroughly analyze the problems, and take effective preventive measures to ensure the safe operation of the equipment system.

[0003] During the process of the supercritical steam turbine generator set running with load, the inlet steam flow of the steam turbine is mainly regulated by the high-pressure control valve, while the high-pressure main steam valve, the intermediate-pressure main steam valve, and the intermediate-pressure control valve are in the fully open state for a long time. In order to prevent valve seizure, it is necessary to regularly conduct a valve activity (steam valve activity during operation) test. Currently, the steam valve activity test during operation is a full-stroke test. During the test, the steam turbine cylinder is in the state of single-sided steam inlet for a short time, which has a certain limit on the maximum load of the unit (the unit load is less than 80% of the rated load during the test).

[0004] During the test, due to the small flow of the pilot solenoid valve of the main steam valve, the influence on the EH system oil pressure is also small in the case of seizure; however, after the oil motive quick-closing solenoid valve of the high-pressure control valve and the intermediate-pressure control valve loses power and the valve closes, when the command is restored, the cartridge valve in the oil drain circuit of the oil motive may seize and cannot reset, resulting in the oil motive being in the oil return state all the time; at the same time, the valve position command of the control valve still exists. Since the valve cannot be opened, the valve position command will reach the maximum at this time, making the flow of the servo valve reach the maximum. After the pressure oil and the return oil are connected, the EH oil pressure drops rapidly, and finally the unit will stop due to the low EH oil pressure. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects of the prior art, and thus provide a method and system for a steam valve activity test during the operation of a 1000MW unit.

[0006] To solve the above technical problems, the method for a steam valve activity test during the operation of a 1000MW unit provided by the technical solution of the present invention includes:

[0007] Steps of a single-sided main steam valve activity test: controlling a single-sided main steam valve to gradually close from the fully open position; when the opening and closing degree of the single-sided main steam valve is greater than a first preset opening and closing degree, or when the feedback time of the single-sided main steam valve leaving the fully open position exceeds a first preset feedback time, controlling the single-sided main steam valve to open to the fully open position to complete the single-sided main steam valve activity test; and

[0008] Single-sided medium-pressure governor valve movement test steps: Control the single-sided medium-pressure governor valve to gradually close from the fully open position to the second preset opening / closing degree; when the single-sided medium-pressure governor valve exceeds the preset holding time at the second preset opening / closing degree, or when the single-sided medium-pressure governor valve leaves the fully open feedback time exceeds the second preset feedback time, control the single-sided medium-pressure governor valve to open to the fully open position to complete the single-sided medium-pressure governor valve movement test.

[0009] As an improvement of the above method, the single-sided main steam valve includes: the first-side high-pressure main steam valve, the second-side high-pressure main steam valve, the first-side medium-pressure main steam valve, and the second-side medium-pressure main steam valve, and during a single-sided main steam valve movement test, only one main steam valve is tested; the single-sided medium-pressure governor valve includes: the first-side medium-pressure governor valve and the second-side medium-pressure governor valve, and during a single-sided medium-pressure governor valve movement test, only one medium-pressure governor valve is tested.

[0010] As an improvement of the above method, the first preset opening / closing degree is 15%.

[0011] As an improvement of the above method, the opening and closing actions of the single-sided main steam valve are controlled by the direction solenoid valve on the oil motor. When the direction solenoid valve is energized, the single-sided main steam valve performs a closing action. When the direction solenoid valve is de-energized, the single-sided main steam valve performs an opening action.

[0012] As an improvement of the above method, the opening and closing actions of the single-sided medium-pressure governor valve are controlled by an electro-hydraulic servo valve.

[0013] As an improvement of the above method, the single-sided medium-pressure governor valve movement test steps specifically include: setting the valve limit set value of the single-sided medium-pressure governor valve to 85%, and controlling the opening / closing degree of the single-sided medium-pressure governor valve to close to 85% through the electro-hydraulic servo valve; when the single-sided medium-pressure governor valve exceeds 5 seconds in the state of 85% opening / closing degree, or the single-sided medium-pressure governor valve leaves the fully open feedback exceeds the second preset feedback time, restore the valve limit set value to 105%, and control the single-sided medium-pressure governor valve to open to the fully open position through the electro-hydraulic servo valve.

[0014] As an improvement of the above method, it further includes: the comprehensive movement test steps of the main steam valve and governor valve on the same side: control the governor valve on this side to gradually close from its original position to the fully closed position, and the governor valve on the other side to gradually open from its original position to the third preset opening / closing degree; through several solenoid valves connected to the main steam valve on this side, respectively control the main steam valve on this side to perform opening and closing actions to conduct several single-sided main steam valve movement tests, so as to conduct movement tests on the solenoid valves respectively; control the governor valve on this side and the governor valve on the other side to return to their corresponding original positions to complete the comprehensive movement test of the main steam valve and governor valve on the same side.

[0015] To achieve another object of the present invention, the present invention further provides a system for a valve activity test during operation of a 1000MW unit, which is used for the above-mentioned method for a valve activity test during operation of a 1000MW unit; the system is implemented based on a DEH system, and comprises:

[0016] A single-side main steam valve activity test module is used to control the single-side main steam valve to gradually close from a fully open position; when the opening and closing degree of the single-side main steam valve is greater than a first preset opening and closing degree, or when the single-side main steam valve leaves the fully open feedback time for more than the first preset feedback time, control the single-side main steam valve to open to the fully open position, and complete the single-side main steam valve activity test; and

[0017] Single-sided medium pressure regulating valve activity test module: used to control the single-sided medium pressure regulating valve to gradually close from the fully open position to the second preset opening and closing degree; when the single-sided medium pressure regulating valve exceeds the preset holding time at the second preset opening and closing degree, or when the single-sided medium pressure regulating valve leaves the fully open feedback time for more than the second preset feedback time, the single-sided medium pressure regulating valve is controlled to open to the fully open position to complete the single-sided medium pressure regulating valve activity test.

[0018] As an improvement of the above system, the system further comprises: a main steam valve regulating valve comprehensive activity test module on the same side, used for controlling the regulating valve on the same side to gradually close from its original position to a fully closed position, and the regulating valve on the other side to gradually open from its original position to a third preset opening and closing degree;

[0019] Through a plurality of solenoid valves connected to the main steam valve on the side, the main steam valve on the side is controlled to perform opening and closing actions respectively, so as to perform a plurality of single-side main steam valve activity tests, thereby performing activity tests on the solenoid valves respectively;

[0020] Control the regulating valve on this side and the regulating valve on the other side to return to the corresponding original positions to complete the comprehensive activity test of the main steam valve regulating valve on the same side.

[0021] As an improvement to the above system, the DEH system is provided with: a first-side high-pressure main steam valve test button, a second-side high-pressure main steam valve test button, a first-side intermediate-pressure main steam valve test button, and a second-side intermediate-pressure main steam valve test button; when the main steam valve test button corresponding to any main steam valve is pressed and double-confirmed, the single-side main steam valve movement test module conducts a movement test on this main steam valve; the DEH system is provided with: a first-side intermediate-pressure governor valve test button and a second-side intermediate-pressure governor valve test button; when the governor valve test button corresponding to any intermediate-pressure governor valve is pressed and double-confirmed, the single-side intermediate-pressure governor valve movement test module conducts an intermediate-pressure governor valve test on this intermediate-pressure governor valve; the DEH system is further provided with: a first-side main steam valve-governor valve comprehensive movement test button and a second-side main steam valve-governor valve comprehensive movement test button; when the main steam valve-governor valve comprehensive movement test button corresponding to any side is pressed and double-confirmed, the same-side main steam valve-governor valve comprehensive movement test module conducts a comprehensive movement test on the main steam valve-governor valve on this side; among them, at the same time, only one of the first-side high-pressure main steam valve test button, the second-side high-pressure main steam valve test button, the first-side intermediate-pressure main steam valve test button, the second-side intermediate-pressure main steam valve test button, the first-side intermediate-pressure governor valve test button, the second-side intermediate-pressure governor valve test button, the first-side main steam valve-governor valve comprehensive movement test button, and the second-side main steam valve-governor valve comprehensive movement test button is in operation.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] 1) During the test of the regulating valve, the oil drain amount of the quick-closing solenoid valve of the oil motor is relatively large, which is likely to cause a significant drop in the EH oil pressure and pose a risk of unit trip; through logic optimization, the valve opening and closing control is changed from the quick-closing solenoid valve to the servo valve, reducing the oil drain amount. This technology reduces the risk of unit trip and saves operation costs at the same time.

[0024] 2) When the valve position feedback is less than 85% or the oil motor directional solenoid valve loses power 1 second after the valve leaves the fully open feedback, the valve reopens to the fully open position.

[0025] 3) After logic optimization, during the partial stroke and full stroke movement tests, the EH oil pressure is relatively stable and there is no significant drop in the EH oil pressure, greatly reducing the risk of unit trip caused by the drop in the EH oil pressure. Description of the Drawings

[0026] Figure 1 It is the logic diagram of the "15% TEST" enable / disable button for the left high-pressure main steam valve;

[0027] Figure 2 It is the logic diagram of the stroke movement test for the left high-pressure main steam valve;

[0028] Figure 3 It is the logic diagram of the "15% TEST" enable / disable button for the left intermediate-pressure governor valve;

[0029] Figure 4 It is the logic diagram of the stroke movement test for the left medium-pressure governing valve;

[0030] Figure 5 It is the interface diagram of the existing DEH system;

[0031] Figure 6 It is the DEH system interface diagram after applying the method of valve movement test during operation applicable to 1000MW units to the DEH system. Specific implementation manners

[0032] The following further illustrates the technical solutions provided by the present invention in conjunction with embodiments.

[0033] To reduce the risk of turbine trip caused by the rapid drop of EH oil pressure during the valve movement test during operation, and at the same time ensure the normal conduct of the turbine valve movement test, the applicant studies the feasibility of optimizing the valve movement test logic during operation, and reduces or eliminates the risk of turbine trip caused by the significant drop of EH oil pressure during the test through logic optimization.

[0034] The N1000-31 / 600 / 620 type steam turbine, as an existing ultra-supercritical unit, adopts a full-arc admission steam distribution mode for its steam turbine. Both the high-pressure cylinder and the medium-pressure cylinder are tangential admission. High-pressure valves are respectively arranged on both sides of the high-pressure cylinder, and medium-pressure valves are respectively arranged on both sides of the medium-pressure cylinder. The valves are directly connected to the corresponding cylinders without steam guide pipes. After the steam passes through the high-pressure valves and the single-flow high-pressure cylinder, it enters the two reheaters respectively from the two exhaust ports at the lower part of the high-pressure cylinder. After being heated by the two reheaters, the steam enters the double-flow medium-pressure cylinder through the two reheater stop valves. It enters the two double-flow low-pressure cylinders respectively through the medium-low pressure connecting pipes at the top of the medium-pressure outer cylinder.

[0035] This embodiment takes the N1000-31 / 600 / 620 type steam turbine as an example to illustrate the method of valve movement test during operation applicable to 1000MW units.

[0036] The left main steam valve and the right main steam valve are respectively arranged on both sides of the high-pressure cylinder. The left medium-pressure main steam valve and the right medium-pressure main steam valve are respectively arranged on both sides of the medium-pressure cylinder. All main steam valves are respectively configured in series with the corresponding governing valves, and the governing valves are located behind the main steam valves. During normal operation, the main steam valves are usually fully open, and the steam flow is adjusted through the governing valves.

[0037] The DEH (Digital Electro-Hydraulic) system refers to the digital electro-hydraulic control system, which is an important part of the modern steam turbine control system. The DEH system combines digital control technology and electro-hydraulic actuators to achieve precise control and adjustment of the steam turbine. Figure 5 The interface diagram of the existing DEH system is shown.

[0038] Figure 6 Shows the DEH system interface diagram after applying the method for valve activity test during the operation of a 1000MW unit provided in this embodiment to the DEH system. As Figure 6 shown, on the valve activity interface during the operation of the DEH control system, an independent "15% TEST" enable / disable button is added to each of the high-pressure main steam valve, intermediate-pressure main steam valve, and intermediate-pressure governor valve, for a total of 6 buttons; the corresponding single valve is subjected to a partial stroke activity test by operating this test button.

[0039] Experimental requirements:

[0040] 1) All buttons shall have double confirmation.

[0041] 2) Only one button can be enabled at a time, and two or more buttons cannot be enabled simultaneously.

[0042] 3) The button turns red after being enabled: indicating that the partial stroke activity test of the valve on that side is in progress; it turns green after being disabled: indicating that the partial stroke activity test function has been exited.

[0043] 4) The left and right sides of each button are clear, and the distributed control system (DCS) is consistent with the on-site action.

[0044] The high-pressure main steam valve and the intermediate-pressure main steam valve are two-position valves that are fully open or fully closed, and the valve opening cannot be accurately positioned. The opening and closing actions of the main steam valve are controlled by the directional solenoid valve on the oil motor; after the partial stroke activity test button is enabled and double confirmed, the directional solenoid valve of the oil motor corresponding to the main steam valve is energized, and the valve starts to close slowly. Figure 1 Shows the logic diagram of the "15% TEST" enable / disable button for the left high-pressure main steam valve. The figure shows that during the single valve stroke activity test of the left high-pressure main steam valve, the "15% TEST" enable / disable button for the left high-pressure main steam valve is enabled, and other "15% TEST" buttons are disabled.

[0045] Figure 2 Taking the left high-pressure main steam valve as an example, shows the logic diagram of the stroke activity test of the main steam valve.

[0046] The process of the stroke activity test of the main steam valve is as follows:

[0047] 1) When the position feedback of the main steam valve is less than 85%, the activity test command signal is automatically reset, the directional solenoid valve of the oil motor is de-energized, and the valve reopens to the fully open position, and the test process ends. Figure 2 Shows the logic of the de-energization command of the directional solenoid valve of the oil motor.

[0048] 2) After the main steam valve leaves the fully open feedback, it is timed for X seconds (the time needs to be accurately set after on-site tests), the directional solenoid valve of the oil motor is de-energized, and the valve reopens to the fully open position, and the test process ends.

[0049] The above two conditions are in an "OR" relationship. When either condition is met, the solenoid valve of the oil motor loses power, and the valve reopens to the fully open position. Even if the position feedback signal of the valve fails, the closing time can be used to limit the closing position of the valve movement test to ensure that the valve can open normally. The left main steam valve, right main steam valve, left intermediate pressure main steam valve, and right intermediate pressure main steam valve can all apply the above process of the main steam valve stroke movement test.

[0050] The process of the intermediate pressure governor valve partial stroke movement test is as follows:

[0051] After the button is put in and double - confirmed, Figure 4 Taking the left intermediate pressure governor valve as an example, the logic diagram of the intermediate pressure governor valve partial stroke movement test is shown. Precise positioning control is carried out by the electro - hydraulic servo valve, and the intermediate pressure governor valve movement test is carried out by reducing the valve limit. The control logic automatically sets the valve limit set value corresponding to the intermediate pressure governor valve to 85%. Under the action of the valve limit, the opening of the intermediate pressure governor valve is slowly reduced to 85% through the electro - hydraulic servo valve command; after maintaining for 5 seconds, the valve limit set value automatically returns to 105%, and the intermediate pressure governor valve slowly returns to the fully open position under the control of the servo valve, and the test process ends.

[0052] After the intermediate pressure governor valve leaves the fully open feedback, it starts to count down for X seconds (the time needs to be accurately set after on - site tests). The logic automatically resets, the valve limit set value automatically returns to 105%, and the intermediate pressure governor valve slowly returns to the fully open position under the control of the servo valve, and the test process ends. Figure 3 The logic diagram of the "15% TEST" put - in and withdrawal button of the left intermediate pressure governor valve during the partial stroke movement test of the intermediate pressure governor valve is shown.

[0053] The above two conditions are in an "OR" relationship. When either condition is met, the intermediate pressure governor valve reopens to the fully open position. Even if the position feedback signal of the intermediate pressure governor valve fails, the closing time can be used to limit the closing position of the intermediate pressure governor valve movement test to ensure that the intermediate pressure governor valve can open normally.

[0054] The process of the full - stroke test of a single - side valve group is as follows:

[0055] On the basis of the original in - operation steam valve movement test, an "In - operation steam valve movement NO CV" put - in and withdrawal button is added to realize the automatic cut - off of the governor valve in - operation steam valve movement function during the in - operation steam valve movement test of a single - side valve group (main steam valve + governor valve). The process is as follows:

[0056] When conducting the test on the unilateral valve group (main steam valve + governing valve), the governing valve on that side closes slowly according to the valve limit command, and the governing valve on the other side opens simultaneously, and the opening size is controlled according to the load command. After the governing valve under test is completely closed, the main steam valve movement test and the trip solenoid valve movement test are carried out. The two solenoid valves of the main steam valve act once respectively, causing the corresponding valves to move twice, and giving the feedback of successful test. The main steam valve test is completed; after the main steam valve test is completed, the main steam valve on that side is opened. After the main steam valve is fully opened, the governing valve starts to open, and at the same time, the governing valve on the opposite side starts to close until it returns to the state before the test.

[0057] Retain the original valve limit protection clearing logic during the test, which continues to be effective.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for testing the valve movement during operation of a 1000MW unit, comprising: The steps of the single-side main steam valve activity test are as follows: control the single-side main steam valve to gradually close from the fully open position; When the opening and closing degree of the single-side main steam valve is greater than the first preset opening and closing degree, or when the single-side main steam valve is away from the full-open feedback time for more than the first preset feedback time, the single-side main steam valve is controlled to open to the full-open position to complete the single-side main steam valve activity test; and The steps of the single-sided medium pressure regulating valve activity test are as follows: control the single-sided medium pressure regulating valve to gradually close from the fully open position to the second preset opening and closing degree; when the single-sided medium pressure regulating valve exceeds the preset holding time at the second preset opening and closing degree, or when the single-sided medium pressure regulating valve leaves the fully open feedback time for more than the second preset feedback time, control the single-sided medium pressure regulating valve to open to the fully open position to complete the single-sided medium pressure regulating valve activity test.

2. The method for valve movement test in operation of a 1000MW unit according to claim 1 is characterized in that: The single-side main steam valve comprises: a first-side high-pressure main steam valve, a second-side high-pressure main steam valve, a first-side medium-pressure main steam valve and a second-side medium-pressure main steam valve, and in a single-side main steam valve activity test process, only one main steam valve is tested; The single-side medium pressure regulating valve includes: a first-side medium pressure regulating valve and a second-side medium pressure regulating valve, and during a single-side medium pressure regulating valve activity test, only one medium pressure regulating valve is tested.

3. The method for valve movement test in operation of a 1000MW unit according to claim 1 is characterized in that: The first preset opening and closing degree is 15%.

4. The method for valve movement test in operation of a 1000MW unit according to claim 1 is characterized in that: The switching action of the single-side main steam valve is controlled by the directional solenoid valve on the oil motor. When the directional solenoid valve is energized, the single-side main steam valve performs a closing action. When the directional solenoid valve loses power, the single-side main steam valve performs an opening action.

5. The method for valve movement test in operation of a 1000MW unit according to claim 1 is characterized in that: The opening and closing action of the single-side medium-pressure regulating valve is controlled by an electro-hydraulic servo valve.

6. The method for valve movement test in operation of a 1000MW unit according to claim 5 is characterized in that: The steps of the one-side medium voltage regulating valve activity test specifically include: The valve limit setting value of the one-side medium pressure regulating valve is set to 85%, and the opening and closing degree of the one-side medium pressure regulating valve is controlled to be closed to 85% by the electro-hydraulic servo valve; When the single-sided medium-pressure regulating valve is in the open and closed state of 85% for more than 5 seconds, or the single-sided medium-pressure regulating valve leaves the full-open feedback for more than the second preset feedback time, the recovery valve limit setting value is 105%, and the single-sided medium-pressure regulating valve is controlled to open to the full-open position through the electro-hydraulic servo valve.

7. The method for valve movement test in operation of a 1000MW unit according to claim 5 is characterized in that: Also includes: The steps of the comprehensive activity test of the main steam valve regulating valve on the same side are as follows: the regulating valve on the same side is controlled to gradually close from its original position to the fully closed position, and the regulating valve on the other side is gradually opened from its original position to the third preset opening and closing degree; Through a plurality of solenoid valves connected to the main steam valve on the side, the main steam valve on the side is controlled to perform opening and closing actions respectively, so as to perform a plurality of single-side main steam valve activity tests, thereby performing activity tests on the solenoid valves respectively; Control the regulating valve on this side and the regulating valve on the other side to return to the corresponding original positions to complete the comprehensive activity test of the main steam valve regulating valve on the same side.

8. A system suitable for a valve activity test during operation of a 1000MW unit, used for executing the method suitable for a valve activity test during operation of a 1000MW unit as claimed in any one of claims 1 to 7; The system is implemented based on the DEH system and includes: The single-side main steam valve activity test module is used to control the single-side main steam valve to gradually close from the fully open position; When the opening and closing degree of the single-side main steam valve is greater than the first preset opening and closing degree, or when the single-side main steam valve is away from the full-open feedback time for more than the first preset feedback time, the single-side main steam valve is controlled to open to the full-open position to complete the single-side main steam valve activity test; and Single-sided medium pressure regulating valve activity test module: used to control the single-sided medium pressure regulating valve to gradually close from the fully open position to the second preset opening and closing degree; when the single-sided medium pressure regulating valve exceeds the preset holding time at the second preset opening and closing degree, or when the single-sided medium pressure regulating valve leaves the fully open feedback time for more than the second preset feedback time, the single-sided medium pressure regulating valve is controlled to open to the fully open position to complete the single-sided medium pressure regulating valve activity test.

9. The system for valve movement test in operation of a 1000MW unit according to claim 1 is characterized in that: Also includes: The main steam valve regulating valve comprehensive activity test module on the same side is used to control the regulating valve on the same side to gradually close from its original position to the fully closed position, and the regulating valve on the other side to gradually open from its original position to a third preset opening and closing degree; Through a plurality of solenoid valves connected to the main steam valve on the side, the main steam valve on the side is controlled to perform opening and closing actions respectively, so as to perform a plurality of single-side main steam valve activity tests, thereby performing activity tests on the solenoid valves respectively; Control the regulating valve on this side and the regulating valve on the other side to return to the corresponding original positions to complete the comprehensive activity test of the main steam valve regulating valve on the same side.

10. The system for valve movement test in operation of 1000MW unit according to claim 9, characterized in that: The DEH system is provided with: a first-side high-pressure main steam valve test button, a second-side high-pressure main steam valve test button, a first-side medium-pressure main steam valve test button, and a second-side medium-pressure main steam valve test button; when the main steam valve test button corresponding to any main steam valve is pressed and confirmed twice, the single-side main steam valve activity test module performs an activity test on the main steam valve; The DEH system is provided with: a first-side medium-pressure regulating valve test button and a second-side medium-pressure regulating valve test button; when the regulating valve test button corresponding to any medium-pressure regulating valve is pressed and confirmed twice, the medium-pressure regulating valve activity test module on one side performs a medium-pressure regulating valve test on the medium-pressure regulating valve; The DEH system is also provided with: a first-side main steam valve adjustment valve comprehensive activity test button and a second-side main steam valve adjustment valve comprehensive activity test button; when the main steam valve adjustment valve comprehensive activity test button corresponding to either side is pressed and confirmed twice, the main steam valve adjustment valve comprehensive activity test module on the same side performs a comprehensive activity test on the main steam valve adjustment valve on that side; wherein, At the same time, only one button among the first side high-pressure main steam valve test button, the second side high-pressure main steam valve test button, the first side medium-pressure main steam valve test button, the second side medium-pressure main steam valve test button, the first side medium-pressure regulating valve test button, the second side medium-pressure regulating valve test button, the first side main steam valve regulating valve comprehensive activity test button and the second side main steam valve regulating valve comprehensive activity test button is put into operation.

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