System for preventing steam turbine generator unit from non-stop caused by EH oil leakage and control method thereof

Abstract

The invention discloses a system for preventing non-stop of a steam turbine generator unit caused by EH oil leakage. The system comprises two main valve oil ways and four to six adjusting valve oil ways. The oil inlet ends of the two main throttle valve oil ways are both connected to an outlet of the EH oil pump. The oil inlet ends of the four to six adjusting valve oil ways are all connected to a second flow meter, and the other end of the second flow meter is connected to an outlet of the EH oil pump. The invention further discloses a control method of the system for preventing non-stop of the steam turbine generator unit caused by EH oil leakage. The system solves the problems that in the prior art, an original EH oil system is few in monitoring data, leakage of a hydraulic servo-motor cannot be monitored, and a quick isolation means is lacked after the leakage is found.

Description

Technical Field

[0001] The present invention belongs to the technical field of EH system control, and particularly relates to a system for preventing the turbine generator set from tripping due to EH oil leakage. The present invention also relates to a control method for the system for preventing the turbine generator set from tripping due to EH oil leakage. Background Art

[0002] The steam inlet valves of steam turbines in thermal power plants include two types: main steam valves and governing valves. The main steam valve is mainly responsible for quickly blocking and isolating the steam inlet of the steam turbine to ensure the safety of the unit in emergency situations; the governing valve can be adjusted between 0% and 100% according to the instructions from the main control room to control the change of the steam inlet volume of the steam turbine and achieve the adjustment and control of the rotational speed or load of the steam turbine. Both types of steam valves are controlled by a high-pressure fire-resistant oil (EH oil) system, which is a hydraulic control method. Through a complex oil circuit, the high-pressure fire-resistant oil overcomes the resistance of the piston spring of the oil motor to control the opening of the steam valve, and the closing of the steam valve is quickly achieved by discharging the pressure oil in the oil motor and under the action of the spring force. Steam is the power source of the steam turbine, and the steam valve is the only means on the machine side that can control the steam volume. If out of control, abnormal shutdown events and even accidents will occur. Therefore, the EH oil system usually has a complete emergency shutdown oil circuit. OPC (Overspeed Protection Control) is the oil circuit used to control the governing valve, and AST (Automatic Shutdown Trip) is the oil circuit used to control the main steam valve. To prevent the EH oil system from losing pressure, pressure switches and local pressure gauges are equipped in the emergency shutdown system, which can facilitate the staff to observe the operation status of the EH oil on the steam turbine platform. The on-off of the oil circuit is controlled by the movement of the spool in the solenoid valve or servo valve. The local pressure gauge can observe the oil pressure, but it is not connected to the DCS (Distributed Control System) in front of the console. If oil leakage occurs, the change in the reading of the local pressure gauge cannot be transmitted to the console operators in time, which prolongs the response time of the console operators to emergency events and is not conducive to the safe and stable operation of the system.

[0003] In recent years, there have been many unplanned shutdown events of the unit caused by the leakage of the quick-closing solenoid valve of the main steam valve, which has caused great economic losses to thermal power plants. Experience shows that the reliability of the steam valve oil motor is not strong, the monitoring means are insufficient, and the monitoring timeliness is weak. It is necessary to improve it to ensure that the steam valve control system has a complete control method, so as to effectively avoid equipment failures, ensure the safety of unit operation, reduce the dependence of equipment safety on personnel patrols, and reduce the probability of unplanned shutdown events. Summary of the Invention

[0004] The object of the present invention is to provide a system for preventing the turbine generator unit from tripping due to EH oil leakage, which solves the problems existing in the prior art, such as few monitoring data in the original EH oil system, inability to monitor the leakage of the oil servo motor, and lack of rapid isolation means after discovery.

[0005] Another object of the present invention is to provide a control method for the system for preventing the turbine generator unit from tripping due to EH oil leakage.

[0006] The technical solution adopted by the present invention is that the system for preventing the turbine generator unit from tripping due to EH oil leakage includes 2 main steam valve oil circuits and 4 - 6 governor valve oil circuits; the inlet ends of the 2 main steam valve oil circuits are both connected to the outlet of the EH oil pump; the inlet ends of the 4 - 6 governor valve oil circuits are both connected to the second flowmeter, and the other end of the second flowmeter is connected to the outlet of the EH oil pump.

[0007] The features of the present invention also lie in: Each main steam valve oil circuit includes a first flowmeter, one end of the first flowmeter is connected to the outlet of the EH oil pump; the other end of the first flowmeter is divided into two paths, one path is connected with a first solenoid valve, the first solenoid valve is connected with a main steam valve oil servo motor, and the main steam valve oil servo motor is connected with a second solenoid valve; the other path of the other end of the first flowmeter is connected with a first filter, the first filter is connected with a standby solenoid valve, and the standby solenoid valve is connected with a throttle orifice; both the second solenoid valve and the throttle orifice are connected to the lower chamber of the main steam valve oil servo motor.

[0008] The first flowmeter, the first solenoid valve, the second solenoid valve and the standby solenoid valve are all connected to the DCS control system.

[0009] Each governor valve oil circuit includes a pressure gauge, one end of the pressure gauge is connected to the second flowmeter; the other end of the pressure gauge is divided into two paths, one path is connected with a third solenoid valve, the third solenoid valve is connected with a governor valve oil servo motor, and the governor valve oil servo motor is connected with a fourth solenoid valve; the other path of the other end of the pressure gauge is connected with a second filter, the second filter is connected with a controller, and the controller is connected with a standby servo valve; both the fourth solenoid valve and the standby servo valve are connected to the lower chamber of the governor valve oil servo motor.

[0010] The second flowmeter, the third solenoid valve, the fourth solenoid valve, the standby servo valve and the pressure gauge are all connected to the DCS control system.

[0011] Another technical solution adopted by the present invention is that the control method for the system for preventing the turbine generator unit from tripping due to EH oil leakage includes the control method for the main steam valve oil circuit and the control method for the governor valve oil circuit.

[0012] The features of another technical solution of the present invention also lie in: The control method for the main steam valve oil circuit specifically includes the following steps: Step 1: From the time when the steam valve is unhooked to fully opened, record the flow value of the first flowmeter as Q1; from the time when the steam valve closing instruction is issued to fully closed, record the flow value of the first flowmeter as Q2. Step 2: During normal operation of the unit, when the flow rate Q measured by the first flowmeter 主 > MAX(Q1, Q2) × 10%, an alarm is given in front of the control panel, indicating abnormal EH oil inlet of the main steam valve oil motor, and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, then go to Step 3. Step 3: When the oil level of the EH oil tank is lower than the alarm value and the inlet flow rate of the main steam valve oil motor is still higher than MAX(Q1, Q2) × 10% value, the first solenoid valve and the second solenoid valve are closed in series, and at the same time the standby solenoid valve is opened, cutting off the pressure oil inlet and outlet of the main steam valve oil motor, and replacing the main steam valve oil motor. Step 4: After replacement, control the first solenoid valve, the second solenoid valve, and the standby solenoid valve to lose power at the same time, and the oil circuit returns to the main steam valve oil motor control state.

[0013] The control method of the regulating valve oil circuit specifically includes the following steps: Step 1: Set the regulating valve instruction directly from 0% to 100% to open the regulating valve, and record the flow value of the second flowmeter as Q3; set the regulating valve instruction directly from 100% to 0%, and record the flow value of the second flowmeter as Q4. Step 2: During normal operation of the unit, when the flow rate Q measured by the second flowmeter 调节 > MAX(Q3, Q4) × 10%, an alarm is given in front of the control panel, indicating abnormal EH oil inlet of the regulating valve oil motor, and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, then go to Step 3. Step 3: Read the pressure gauge readings of each regulating valve oil circuit, and the regulating valve oil motor of the circuit with a lower pressure value leaks. Step 4: When the oil level of the EH oil tank is lower than the alarm value and the inlet flow rate of the regulating valve oil motor is still higher than MAX(Q3, Q4) × 10% value, the third solenoid valve and the fourth solenoid valve are closed in series, and at the same time the standby servo valve is opened, cutting off the pressure oil inlet and outlet of the regulating valve oil motor, and replacing the regulating valve oil motor. Step 5: After replacement, control the third solenoid valve and the fourth solenoid valve to lose power, and adjust the standby servo valve to the middle position, and the oil circuit returns to the regulating valve oil motor control state.

[0014] The beneficial effects of the present invention are: The system and its control method for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage in the present invention make up for the shortcomings of the original EH oil system, such as few monitored data, inability to monitor the leakage of the oil actuator, and lack of a quick isolation means after problems are found. The flowmeter can measure the real-time flow of the pressure oil of the oil actuator and display it in the DCS system in front of the control panel. If an abnormality occurs, an alarm is started to isolate the originally leaking oil actuator, reminding the operator and giving sufficient time to perform the operation of online replacing the oil actuator, eliminating the non-stop operation event of the unit caused by the abnormality of the EH oil system and reducing the economic loss of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the system for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage in the present invention; Figure 2 is a flowchart of the control method for the main steam valve oil circuit in the control method of the system for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage in the present invention; Figure 3 is a flowchart of the control method for the governing valve oil circuit in the control method of the system for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage in the present invention.

[0016] In the figure, 1 is the first flowmeter; 2 is the lower chamber of the main steam valve oil actuator; 3 is the first solenoid valve; 4 is the main steam valve oil actuator; 5 is the second solenoid valve; 6 is the first filter; 7 is the standby solenoid valve; 8 is the throttle orifice; 9 is the second flowmeter; 10 is the lower chamber of the governing valve oil actuator; 11 is the pressure gauge; 12 is the third solenoid valve; 13 is the governing valve oil actuator; 14 is the fourth solenoid valve; 15 is the second filter; 16 is the controller; 17 is the standby servo valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0018] The system for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage in the present invention includes 2 main steam valve oil circuits and 4 - 6 governing valve oil circuits; the oil inlet ends of the 2 main steam valve oil circuits are both connected to the outlet of the EH oil pump; the oil inlet ends of the 4 - 6 governing valve oil circuits are all connected to the second flowmeter 9, and the other end of the second flowmeter 9 is connected to the outlet of the EH oil pump. As Figure 1 shown, it is the structure of 2 main steam valve oil circuits and 4 governing valve oil circuits, and its principle can be extended to valve structures with different configurations such as 2 main and 6 governing valves. The high-pressure fire-resistant oil comes in two paths, one path goes to the main steam valve oil actuator, and the other path goes to the governing valve oil actuator.

[0019] Each main steam valve oil circuit includes a first flowmeter 1. One end of the first flowmeter 1 is connected to the outlet of the EH oil pump; the other end of the first flowmeter 1 is divided into two paths. One path is connected with a first solenoid valve 3, the first solenoid valve 3 is connected with a main steam valve oil motor 4, and the main steam valve oil motor 4 is connected with a second solenoid valve 5; the first solenoid valve 3 and the second solenoid valve 5 are opened when de-energized and closed when energized. The other path of the other end of the first flowmeter 1 is connected with a first filter screen 6, the first filter screen 6 is connected with a standby solenoid valve 7, the standby solenoid valve 7 is closed when de-energized and opened when energized. The standby solenoid valve 7 is connected with an orifice 8; both the second solenoid valve 5 and the orifice 8 are connected to the lower chamber 2 of the main steam valve oil motor. The first filter screen 6 ensures the purity of the fire-resistant oil entering the oil motor, and the orifice 8 ensures the stable oil pressure of the fire-resistant oil entering the lower chamber of the oil motor. The first flowmeter 1, the first solenoid valve 3, the second solenoid valve 5 and the standby solenoid valve 7 are all connected to the DCS control system. The DCS control system has the control ability to control the first solenoid valve 3, the second solenoid valve 5 and the standby solenoid valve 7.

[0020] Each governing valve oil circuit includes a pressure gauge 11. One end of the pressure gauge 11 is connected to a second flowmeter 9; the other end of the pressure gauge 11 is divided into two paths. One path is connected with a third solenoid valve 12, the third solenoid valve 12 is connected with a governing valve oil motor 13, and the governing valve oil motor 13 is connected with a fourth solenoid valve 14; the third solenoid valve 12 and the fourth solenoid valve 14 are opened when de-energized and closed when energized. The other path of the other end of the pressure gauge 11 is connected with a second filter screen 15, the second filter screen 15 is connected with a controller 16, the controller 16 is connected with a standby servo valve 17, and the controller 16 is used to analyze the steam turbine load and valve sequence during operation to adjust the standby servo valve 17 so as to control the opening degree of the governing valve; both the fourth solenoid valve 14 and the standby servo valve 17 are connected to the lower chamber 10 of the governing valve oil motor. The second flowmeter 9, the third solenoid valve 12, the fourth solenoid valve 14, the standby servo valve 17 and the pressure gauge 11 are all connected to the DCS control system. The DCS control system has the control ability to control the third solenoid valve 12, the fourth solenoid valve 14 and the standby servo 17.

[0021] The control method of the system for preventing the steam turbine generator unit from tripping due to EH oil leakage includes the control method of the main steam valve oil circuit and the control method of the governing valve oil circuit.

[0022] The control method of the main steam valve oil circuit is as Figure 2 shown, and specifically includes the following steps: Step 1: From the valve being on the latch to being fully opened, record the flow value of the first flowmeter 1 as Q1; from the valve closing command being issued to being fully closed, record the flow value of the first flowmeter 1 as Q2; Step 2: When the unit is operating normally, when the flow rate Q measured by the first flowmeter 1 主When it is > MAXQ1, Q2 × 10%, a pre-disk alarm is given, indicating that the EH oil inlet of the main steam valve oil motor 4 is abnormal. It is necessary to immediately go to the site to check the status of the oil motor equipment and continuously monitor the oil level of the EH oil tank. If the EH oil tank oil level shows a continuous downward trend, then proceed to step 3; Step 3: When the oil level of the EH oil tank is lower than the alarm value (the alarm value is set according to the actual production situation) and the inlet flow rate of the main steam valve oil motor 4 is still higher than the value of MAXQ1, Q2 × 10%, the first solenoid valve 3 and the second solenoid valve 5 are closed by interlock, and at the same time, the standby solenoid valve 7 is opened, that is, the three solenoid valves are energized at the same time, cutting off the pressure oil inlet and outlet of the main steam valve oil motor. At this time, the leaking main steam valve oil motor 4 is completely isolated, and the main steam valve oil motor 4 is replaced; the opened standby solenoid valve 7 can ensure that the oil pressure in the lower chamber 2 of the main steam valve oil motor does not decrease, maintaining the opening state of the main steam valve and keeping the system load stable. If the on-site inspection personnel have already found the leakage point, the first solenoid valve 3 and the second solenoid valve 5 can be manually closed through the DCS system, and the standby solenoid valve 7 is opened to enter the online replacement mode.

[0023] Step 4: After the replacement is completed, control the first solenoid valve 3, the second solenoid valve 5, and the standby solenoid valve 7 to lose power at the same time, then the first solenoid valve 3 and the second solenoid valve 5 are opened, and the standby solenoid valve 7 is closed, and the oil circuit returns to the control state of the main steam valve oil motor 2.

[0024] The oil circuit structure of each main steam valve is the same, and the control method is the same.

[0025] The control method of the regulating valve oil circuit is as Figure 3 shown, and specifically includes the following steps: Step 1: Set the regulating valve command directly from 0% to 100% to open the regulating valve, and record the flow value of the second flowmeter 9 as Q3; set the regulating valve command directly from 100% to 0%, and record the flow value of the second flowmeter 9 as Q4; Step 2: When the unit is running normally, when the flow rate Q measured by the second flowmeter 9 调节 > MAXQ3, Q4 × 10%, a pre-disk alarm is given, indicating that the EH oil inlet of the regulating valve oil motor 13 is abnormal. It is necessary to immediately go to the site to check the status of the oil motor equipment. And continuously monitor the oil level of the EH oil tank; if the EH oil tank oil level shows a continuous downward trend, then proceed to step 3; Step 3: Read the pressure gauge 11 readings of each regulating valve oil circuit, and the regulating valve oil motor 13 of the circuit with a lower pressure value leaks; Step 4: When the oil level in the EH oil tank is lower than the alarm value and the oil inlet flow rate of the governing valve oil motor 13 is still higher than the value of MAXQ3, Q4×10%, the third solenoid valve 12 and the fourth solenoid valve 14 are interlocked to close, and at the same time, the standby servo valve 17 is opened to cut off the pressure oil inlet and outlet of the governing valve oil motor. At this time, the leaking governing valve oil motor 13 is completely isolated, and on-line replacement operation can be carried out. If the on-site inspection personnel have found the leakage point, the third solenoid valve 12 and the fourth solenoid valve 14 can be manually closed through the DCS system, and the standby servo valve 17 is opened to enter the on-line replacement mode.

[0026] Since the opening of the governing valve can be adjusted from 0% to 100% through the standby servo valve 17, it is necessary to analyze the current steam turbine load and valve sequence through the controller 16 in front of the standby servo valve 17, so as to adjust the opening and closing of the standby servo valve 17 to make the oil volume in the lower chamber 10 of the governing valve oil motor appropriate, ensure that the governing valve opening is suitable for the current load, and keep the system load stable.

[0027] Step 5: After the replacement is completed, control the third solenoid valve 12 and the fourth solenoid valve 14 to lose power, and adjust the standby servo valve 17 to the middle position, and the oil circuit returns to the control state of the governing valve oil motor 13.

[0028] Embodiment 1 This embodiment provides a system for preventing the turbine generator unit from tripping due to EH oil leakage, as Figure 1 shown, including 2 main steam valve oil circuits and 4 governing valve oil circuits; the oil inlet ends of the 2 main steam valve oil circuits are both connected to the outlet of the EH oil pump; the oil inlet ends of the 4 governing valve oil circuits are all connected to the second flowmeter 9, and the other end of the second flowmeter 9 is connected to the outlet of the EH oil pump.

[0029] Embodiment 2 On the basis of Embodiment 1, each main steam valve oil circuit includes a first flowmeter 1, one end of the first flowmeter 1 is connected to the outlet of the EH oil pump; the other end of the first flowmeter 1 is divided into two paths, one path is connected with a first solenoid valve 3, the first solenoid valve 3 is connected with a main steam valve oil motor 4, the main steam valve oil motor 4 is connected with a second solenoid valve 5; the other path of the other end of the first flowmeter 1 is connected with a first filter screen 6, the first filter screen 6 is connected with a standby solenoid valve 7, and the standby solenoid valve 7 is connected with a throttle orifice 8; the second solenoid valve 5 and the throttle orifice 8 are both connected to the lower chamber 2 of the main steam valve oil motor. The first flowmeter 1, the first solenoid valve 3, the second solenoid valve 5 and the standby solenoid valve 7 are all connected to the DCS control system.

[0030] Embodiment 3 Based on Embodiment 2, each governing valve oil circuit includes a pressure gauge 11. One end of the pressure gauge 11 is connected to the second flowmeter 9; the other end of the pressure gauge 11 is divided into two paths. One path is connected with a third solenoid valve 12, the third solenoid valve 12 is connected with a governing valve oil motor 13, and the governing valve oil motor 13 is connected with a fourth solenoid valve 14; the other path of the other end of the pressure gauge 11 is connected with a second filter 15, the second filter 15 is connected with a controller 16, and the controller 16 is connected with a standby servo valve 17; both the fourth solenoid valve 14 and the standby servo valve 17 are connected to the lower chamber 10 of the governing valve oil motor. The second flowmeter 9, the third solenoid valve 12, the fourth solenoid valve 14, the standby servo valve 17 and the pressure gauge 11 are all connected to the DCS control system.

[0031] The system provided in this embodiment for preventing the turbine generator set from tripping due to EH oil leakage makes up for the shortcomings of the original EH oil system, such as few monitoring data, inability to monitor the leakage of the oil motor, and lack of rapid isolation means after discovery. The flowmeter can measure the real-time flow of the pressure oil of the oil motor and display it in the DCS system in front of the panel. If an abnormality occurs, it can alarm and then isolate the original leaking oil motor, remind the operator and give sufficient time for on-line replacement operation, eliminate the tripping event of the unit caused by the abnormality of the EH oil system, and reduce the economic loss of the power plant.

[0032] Embodiment 4 This embodiment provides a control method for the system of Embodiment 3, specifically including the control method of the main steam valve oil circuit and the control method of the governing valve oil circuit.

[0033] Embodiment 5 Based on Embodiment 4, the control method of the main steam valve oil circuit is as Figure 2 shown, and specifically includes the following steps: Step 1: From the valve being on the latch to being fully opened, record the flow value of the first flowmeter 1 as Q1; from the valve closing command being issued to being fully closed, record the flow value of the first flowmeter 1 as Q2; Step 2: When the unit is operating normally, when the flow rate Q measured by the first flowmeter 1 主 > MAXQ1, Q2×10%, an alarm is given in front of the panel, indicating that the EH oil inlet of the main steam valve oil motor 4 is abnormal, and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, then enter Step 3; Step 3: When the oil level of the EH oil tank is lower than the alarm value and the inlet oil flow rate of the main steam valve oil motor 4 is still higher than the value of MAXQ1, Q2×10%, the first solenoid valve 3 and the second solenoid valve 5 are closed in series, and at the same time the standby solenoid valve 7 is opened, cutting off the inlet and outlet of the pressure oil of the main steam valve oil motor, and replacing the main steam valve oil motor 2; Step 4: After the replacement is completed, control the first solenoid valve 3, the second solenoid valve 5, and the standby solenoid valve 7 to lose power simultaneously, and the oil circuit returns to the control state of the main steam valve oil motor 2.

[0034] Embodiment 6 Based on Embodiment 4, the control method of the governing valve oil circuit is as Figure 3 shown, and specifically includes the following steps: Step 1: Set the governing valve command directly from 0% to 100% to open the governing valve, and record the flow value of the second flowmeter 9 as Q3; set the governing valve command directly from 100% to 0%, and record the flow value of the second flowmeter 9 as Q4; Step 2: When the unit is operating normally, when the flow rate Q measured by the second flowmeter 9 调节 > MAXQ3, Q4 × 10%, an alarm is given in front of the panel, indicating that the EH oil inlet of the governing valve oil motor 13 is abnormal, and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, then go to Step 3; Step 3: Read the pressure gauge readings of each governing valve oil circuit. The governing valve oil motor 13 of the circuit with a relatively low pressure value leaks. Step 4: When the oil level of the EH oil tank is lower than the alarm value and the inlet oil flow rate of the governing valve oil motor 13 is still higher than the value of MAXQ3, Q4 × 10%, interlock to close the third solenoid valve 12 and the fourth solenoid valve 14, and at the same time open the standby servo valve 17 to cut off the inlet and outlet of the pressure oil of the governing valve oil motor, and replace the governing valve oil motor 13; Step 5: After the replacement is completed, control the third solenoid valve 12 and the fourth solenoid valve 14 to lose power, and adjust the standby servo valve 17 to the middle position, and the oil circuit returns to the control state of the governing valve oil motor 13.

Claims

1. A system for preventing the turbine generator set from tripping due to EH oil leakage, characterized in that, It includes two main steam valve oil circuits and four to six governing valve oil circuits; the oil inlet ends of the two main steam valve oil circuits are both connected to the outlet of the EH oil pump; the oil inlet ends of the four to six governing valve oil circuits are all connected to the second flowmeter (9), and the other end of the second flowmeter (9) is connected to the outlet of the EH oil pump.

2. The system for preventing the turbine generator set from tripping due to EH oil leakage according to claim 1, wherein Each main steam valve oil circuit includes a first flowmeter (1), and one end of the first flowmeter (1) is connected to the outlet of the EH oil pump; the other end of the first flowmeter (1) is divided into two paths, one path is connected with a first solenoid valve (3), the first solenoid valve (3) is connected with a main steam valve oil motor (4), and the main steam valve oil motor (4) is connected with a second solenoid valve (5); the other path of the other end of the first flowmeter (1) is connected with a first filter screen (6), the first filter screen (6) is connected with a standby solenoid valve (7), and the standby solenoid valve (7) is connected with a throttle orifice (8); both the second solenoid valve (5) and the throttle orifice (8) are connected to the lower chamber (2) of the main steam valve oil motor.

3. The system for preventing the non-stop operation of the steam turbine generator set caused by the leakage of EH oil according to claim 2, characterized in that, The first flowmeter (1), the first solenoid valve (3), the second solenoid valve (5) and the standby solenoid valve (7) are all connected to the DCS control system.

4. The system for preventing the turbine generator unit from tripping due to EH oil leakage according to claim 1, characterized in that, Each governing valve oil circuit includes a pressure gauge (11), and one end of the pressure gauge (11) is connected to the second flowmeter (9); the other end of the pressure gauge (11) is divided into two paths, one path is connected with a third solenoid valve (12), the third solenoid valve (12) is connected with a governing valve oil motor (13), and the governing valve oil motor (13) is connected with a fourth solenoid valve (14); the other path of the other end of the pressure gauge (11) is connected with a second filter screen (15), the second filter screen (15) is connected with a controller (16), and the controller (16) is connected with a standby servo valve (17); both the fourth solenoid valve (14) and the standby servo valve (17) are connected to the lower chamber (10) of the governing valve oil motor.

5. The system for preventing the non-stop operation of a steam turbine generator set caused by EH oil leakage according to claim 4, wherein The second flowmeter (9), the third solenoid valve (12), the fourth solenoid valve (14), the standby servo valve (17) and the pressure gauge (11) are all connected to the DCS control system.

6. The control method of the system for preventing the non-stop operation of the steam turbine generator set caused by the EH oil leakage according to any one of claims 1 to 5, characterized in that, It includes a control method for the main steam valve oil circuit and a control method for the governing valve oil circuit.

7. The control method of the system for preventing the non-stop operation of the steam turbine generator set caused by the EH oil leakage according to claim 6, characterized in that, The control method for the main steam valve oil circuit specifically includes the following steps: Step 1: From the valve being on the latch to being fully opened, record the flow value of the first flowmeter (1) as Q1; from the valve closing command being issued to being fully closed, record the flow value of the first flowmeter (1) as Q2; Step 2: During normal operation of the unit, when the flow rate Q measured by the first flowmeter (1) 主 > MAX(Q1, Q2) × 10%, an alarm is given in front of the panel, indicating abnormal EH oil inlet of the main steam valve oil motor (4), and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, go to Step 3; Step 3: When the oil level in the EH oil tank is lower than the alarm value and the inlet oil flow of this main steam valve oil motor (4) is still higher than MAX(Q1, Q2)×10% value, interlock to close the first solenoid valve (3) and the second solenoid valve (5), and at the same time open the standby solenoid valve (7) to cut off the inlet and outlet of the pressure oil of this main steam valve oil motor and replace the main steam valve oil motor (4); Step 4: After the replacement is completed, control the first solenoid valve (3), the second solenoid valve (5), and the standby solenoid valve (7) to lose power simultaneously, and the oil circuit returns to the control state of the main steam valve oil motor (4).

8. The control method of the system for preventing the non-stop operation of the steam turbine generator set caused by the EH oil leakage according to claim 6, characterized in that, The control method for the governing valve oil circuit specifically includes the following steps: Step 1: Set the throttle valve command directly from 0% to 100% to open the throttle valve, and record the flow value of the second flowmeter (9) as Q3; set the throttle valve command directly from 100% to 0%, and record the flow value of the second flowmeter (9) as Q4; Step 2: When the unit is operating normally, when the flow rate Q measured by the second flowmeter (9) 调节 > MAX(Q3, Q4) × 10%, an alarm is given in front of the panel, indicating abnormal EH oil inlet of the governing valve oil motor (13), and continuously monitor the oil level of the EH oil tank; if the oil level of the EH oil tank shows a continuous downward trend, go to Step 3; Step 3: Read the pressure gauge (11) readings of each throttle valve oil circuit. The throttle valve oil motor (13) of the circuit with a lower pressure value leaks; Step 4: When the EH oil tank oil level is lower than the alarm value and the inlet oil flow of the throttle valve oil motor (13) is still higher than MAX(Q3, Q4)×10% value, interlock to close the third solenoid valve (12) and the fourth solenoid valve (14), and at the same time open the standby servo valve (17) to cut off the pressure oil inlet and outlet of the throttle valve oil motor, and replace the throttle valve oil motor (13); Step 5: After replacement, control the third solenoid valve (12) and the fourth solenoid valve (14) to lose power, adjust the standby servo valve (17) to the middle position, and the oil circuit returns to the control state of the throttle valve oil motor (13).

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