A system and method for early warning of EH oil temperature regulation failure during operation of steam turbine EH oil system

Abstract

The invention discloses an EH oil temperature regulation failure warning system and method under the operation of a steam turbine EH oil system, including a subtractor module, a rate block, an absolute value module, a large value selection module, a small value selection module, a delay block, a phase and block, etc. for the EH oil temperature regulation failure warning control logic. The EH oil pump operation, the EH oil pump current, the EH oil pump mother pipe oil pressure and the EH oil temperature change are used as the judgment basis for the EH oil temperature regulation failure warning control. The invention can inform the operating personnel through early warning prompts to prevent the problem of EH oil temperature regulation failure in advance. When the EH oil temperature is too high, the EH oil will be oxidized and decomposed, the acid value inside the EH oil will increase sharply, and the acid value of the EH oil will increase, resulting in the deterioration of the oil quality, reducing the safety of the EH oil control system, and long-term corrosion will aggravate the internal leakage of the system components. When the internal leakage is serious, it will cause the components controlling the EH oil system to malfunction or refuse to operate, and the safe and long-term operation of the unit cannot be guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal control of steam turbine EH oil system, and specifically relates to an EH oil temperature regulation failure warning system and method when the steam turbine EH (full name in Chinese is hydraulic control system, full name in English is Electro Hydraulic) oil system is running. Background Art

[0002] The EH oil system is a key part of the turbine control system. If the EH oil system fails, it will seriously affect the safety of the normal operation of the unit. Therefore, when the EH oil temperature rises, it must be taken seriously, and the cause must be found and dealt with in time. Strengthening the supervision, operation, maintenance and management of the EH oil system is of great significance to extending the service life of the EH oil system and safe and economical operation.

[0003] The main component of EH oil is triaryl phosphate type synthetic oil. If the temperature of EH oil rises, it will accelerate the oxidation and decomposition of fire-resistant oil, gradually increase the acidity, and deepen the color of EH oil. When the temperature of EH oil exceeds about 60℃, the acid value of the oil will increase with the increase of oil temperature, and the oil quality will deteriorate. Due to the sharp increase in the acid value of EH oil, it will accelerate the erosion of various components in the EH oil system, such as the valve cup sealing surface, sealing ring and sliding valve boss. Ultimately, it will reduce the safety of the system operation, causing oil leakage, internal leakage, and component jamming and refusal to operate. In severe cases, it will paralyze the entire EH oil system, causing serious losses and harm. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an EH oil temperature regulation failure warning system and method under the operation of the turbine EH oil system. The method can warn in the case of EH oil temperature regulation failure, allowing the operating personnel to check the EH oil cooling water system in time to prevent the problem of EH oil temperature increase in advance.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An EH oil temperature regulation failure warning system when the EH oil system of a steam turbine is in operation, comprising:

[0007] 1) The AI ​​block of the acquisition module EH oil temperature T is used as the input end of the rate block 1 and is connected to the rate block 1. The output end of the rate block 1 is connected to the input end of the absolute value module 2. The output of the absolute value module 2 and the set value of the maximum value selection module 3 are used as the input end of the maximum value selection module 3 and are connected to the maximum value selection module 3. The output end of the maximum value selection module 3 is connected to the input end of the AND block 10;

[0008] 2) Collection module EH oil main pipe oil pressure P nAverage oil pressure P of AI block and EH oil pipe m The AI ​​block is used as the input end of the subtractor module 4 and is connected to the subtractor module 4. The output end of the subtractor module 4 is connected to the input end of the absolute value module 5. The output end of the absolute value module 5 and the fixed value of the small value selection module 6 are used as the input end of the small value selection module 6 and are connected. The output end of the small value selection module 6 is connected to the input end of the AND block 10.

[0009] 3) Collection module EH oil current I n The AI ​​block and EH oil average current I m The AI ​​block is used as the input end of the subtractor module 7 and is connected to the subtractor module 7. The output end of the subtractor module 7 is connected to the input end of the absolute value module 8. The output end of the absolute value module 8 and the fixed value of the small value selection module 9 are used as the input end of the small value selection module 9 and are connected. The output end of the small value selection module 9 is connected to the input end of the AND block 10.

[0010] 4) The output end of the large value selection module 3, the output end of the small value selection module 6, the output end of the small value selection module 9 and the DI block of the acquisition module turbine operation B are all used as the input end of the phase AND block 10 and are connected to each other. The constants of the phase AND block 10 and the delay block 11 are used as the input end of the delay block 11 and are connected to each other. The output end of the delay block 11 is connected to the input end of the early warning result output module 12. According to the above conditions: EH oil pump operation, EH oil pump current, EH oil pump main pipe oil pressure and EH oil temperature change, as the basis for the EH oil temperature regulation failure early warning judgment criterion.

[0011] The judgment conditions for the EH oil temperature regulation failure warning include: the difference between the EH oil current and the EH average current needs to be within the normal range, the difference between the EH oil mother pipe pressure and the EH average mother pipe pressure needs to be within the normal range, the rate of change of the EH oil temperature is greater than the set value and the EH oil pump is running. All conditions in the control logic need to be met to warn of the EH oil temperature regulation failure.

[0012] A control method for an EH oil temperature regulation failure warning system when an EH oil system of a steam turbine is in operation, comprising the following steps;

[0013] The oil temperature of the EH oil tank is collected as the input of the rate block 1. The value calculated by the rate block 1 is the change rate value of the EH oil temperature. The value calculated by the rate block 1 is used as the input of the absolute value module 2. The absolute value module 2 is used to calculate the absolute value of the data. The output of the absolute value module 2 is used as the input of the maximum value selection module 3. The maximum value selection module 3 is compared with the original constant value 1.5 of the maximum value selection module 3. The value of the output of the maximum value selection module 3 indicates that the change rate of the oil temperature is greater than 1.5℃ / min. The oil temperature rate determined by the maximum value selection module 3 is greater than 1.5℃ / min, and the output is 1, which is used as the input of the phase and block 10. If the output of the maximum value selection module 3 is 0, it will not be used as the input of the phase and block 10. This control logic indicates whether the change of the EH oil temperature affects the internal leakage of the oil system.

[0014] The oil pressure of EH main oil pipe is collected as P n The average oil pressure of the EH oil main pipe is P m They are all used as the input end of the subtractor module 4 and connected, and the subtractor module 4 is used to calculate the difference. The difference calculated by the subtractor module 4 is used as the input end of the absolute value module 5. The absolute value of the data is calculated by the absolute value module 5. The output end of the absolute value module 5 is used as the input end of the small value selection module 6, and is compared with the original constant 0.3 of the small value selection module 6. It means that the fluctuation change of the oil pressure of the EH main pipe is within 0.3MPa. If the fluctuation change of the oil pressure of the EH main pipe determined by the small value selection module 6 is within 0.3MPa, the output end is 1, which is used as the input end of the phase and block 10. If the output end of the large value selection module 3 is 0, it is not used as the input end of the phase and block 10. This control logic indicates whether the change of the oil pressure of the EH main pipe affects the internal leakage of the oil system;

[0015] Collect EH oil current as I n and the average value of EH oil current is I n All of them are used as the input end of the subtractor module 7 and connected, and the difference is calculated by the subtractor module 7. The output end of the subtractor module 7 is used as the input end of the absolute value module 8 and connected, and the absolute value of the data is calculated by the absolute value module 8. The output end of the absolute value module 8 is used as the input end of the small value selection module 9 and connected, and compared with the original constant 0.5 of the small value selection module 9, it means that the fluctuation change of the EH oil current is within 0.5A. If the fluctuation change of the EH oil current determined by the small value selection module 9 is within 0.5A, the output end is 1, which is used as the input end of the phase and block 10. If the output end of the small value selection module 9 is 0, it is not used as the input end of the phase and block 10. This control logic indicates whether the change of the current of the EH oil pump affects the internal leakage of the oil system;

[0016] Collect the operation signal B of the EH oil pump as the input end of the phase AND block 10, and connect it to the phase AND block 10. When the EH oil pump is running, it serves as the input end of the phase AND block 10. When the EH oil pump is not running, it does not serve as the input end of the phase AND block 10.

[0017] The output end of the large value selection module 3, the output end of the small value selection module 6, the output end of the small value selection module 9 and the output end of module B are used as the input end of the phase AND block 10 and are connected to the phase AND block 10. When the output end of the phase AND block 10 is 1, the output end of the phase AND block 10 is connected to the input end of the delay block 11. The delay block 11 is a delay block with a reset function within 3 minutes. When the output end of the phase AND block 10 is 1 and within 3 minutes, the output end of the delay block 11 is 1. When the output end of the phase AND block 10 is not 1 or exceeds 3 minutes, the output end of the delay block 11 is 0. When the output end of the delay block 11 is 1, the early warning push is satisfied at the same time. According to the logical judgment, the EH oil temperature regulation failure is pushed. Please check the EH oil cooling water system in time.

[0018] Beneficial effects of the present invention:

[0019] The present invention enables the operating personnel to determine whether the leakage is caused by the failure of the EH oil temperature regulation according to the early warning prompt, and to go to the scene to deal with the early warning problem in time. Firstly, it effectively avoids the situation that when the oil temperature is too high, the acid value of the EH oil begins to increase and the oil quality deteriorates sharply. The increase in acid value will cause problems such as precipitation, bubbling in the oil and air gaps in the EH fire-resistant oil, and the sealing ring of the component will be corroded more seriously. Secondly, it avoids the erosion and dissolution of some sealing components in the connecting pipelines, and the blockage of components such as the EH oil system filter.

[0020] The present invention strengthens the monitoring, operation, maintenance and management of the EH oil system, which is of great significance for extending the service life of the EH oil and safe and economical operation. The EH oil pump operation, EH oil pump current, EH oil pump main pipe oil pressure and EH oil temperature change are used as the discrimination conditions. Through logical judgment, an early warning of EH oil temperature regulation failure is issued in advance, and the operating personnel are informed in time to check the EH oil cooling water system in time to prevent the problem of EH oil temperature rising in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention.

[0022] Among them, 1 is the rate block, 2 is the absolute value module, 3 is the large value selection module, 4 is the subtractor, 5 is the absolute value module, 6 is the small value selection module, 7 is the subtractor module, 8 is the absolute value module, 9 is the small value selection module, 10 is the phase and block, 11 is the delay block, and 12 is the warning result output module. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0024] like Figure 1 As shown:

[0025] 1) The AI ​​block of the acquisition module EH oil temperature T is used as the input of the rate block 1 and is connected to the rate block 1. The output of the rate block 1 is connected to the input of the absolute value module 2, and the output of the absolute value module 2 and the set value of the maximum value selection module 3 are used as the input of the maximum value selection module 3 and are connected to the maximum value selection module 3. The output of the maximum value selection module 3 is connected to the input of the AND block 10.

[0026] 2) Collection module EH oil main pipe oil pressure P n Average oil pressure P of AI block and EH oil pipe m The AI ​​block of the subtractor module 4 is used as the input of the subtractor module 4 and is connected to the subtractor module 4. The output of the subtractor module 4 is connected to the input of the absolute value module 5. The output of the absolute value module 5 and the fixed value of the small value selection module 6 are used as the input of the small value selection module 6 and are connected. The output of the small value selection module 6 is connected to the input of the AND block 10.

[0027] 3) Collection module EH oil current I n The AI ​​block and EH oil average current I m The AI ​​block of is used as the input of the subtractor module 7 and is connected to the subtractor module 7. The output of the subtractor module 7 is connected to the input of the absolute value module 8. The output of the absolute value module 8 and the fixed value of the small value selection module 9 are used as the input of the small value selection module 9 and are connected. The output of the small value selection module 9 is connected to the input of the AND block 10.

[0028] 4) The output end of the large value selection module 3, the output end of the small value selection module 6, the output end of the small value selection module 9 and the DI block of the acquisition module turbine operation B are all used as the input end of the phase AND block 10 and are connected. The fixed value of the phase AND block 10 and the delay block 11 are all used as the input end of the delay block 11 and are connected. The output end of the delay block 11 is connected to the input end of the early warning result output module 12. According to the above conditions: EH oil pump operation, EH oil pump current, EH oil pump main pipe oil pressure and EH oil temperature change. It is used as the basis for the EH oil temperature regulation failure early warning judgment.

[0029] The control logic can warn that in the case of failure of EH oil temperature regulation, the cause is an increase in EH oil temperature, and the EH oil cooling water system needs to be checked in time.

[0030] The EH oil temperature regulation failure warning criteria are based on the following conditions: EH oil pump operation, EH oil pump current, EH oil pump main pipe oil pressure and EH oil temperature changes.

[0031] The control logic described above can be put into operation only after all test conditions are met, and after being put into operation, abnormal operation and leakage warning of the steam turbine EH oil system can be carried out.

[0032] The control logic sets the oil temperature of the EH tank to T.

[0033] The control logic sets the EH oil main pipe oil pressure to P n , the average oil pressure of EH oil main pipe is P m .

[0034] The control logic sets the EH oil current to I n , the average value of EH oil current is I m .

[0035] The control logic sets the operation of the EH oil pump to B.

[0036] The judgment conditions for the EH oil temperature regulation failure warning in the control logic include: the difference between the EH oil current and the EH average current needs to be within the normal range, the difference between the EH oil mother pipe pressure and the EH average mother pipe pressure needs to be within the normal range, the rate of change of the EH oil temperature is greater than the set value and the EH oil pump is running. All conditions in the control logic need to be met in order to warn of the EH oil temperature regulation failure.

[0037] Each module realizes the early warning function based on the DCS controller of Sciyon NT6000. The specific models and functions of each module are as follows:

[0038] Hysteresis block: The module number is LLAG16762. The parameter name PV in the module is the input value of the module, which is the value of the collected EH oil temperature. The parameter name LD in the module is the hysteresis time constant of the module, which is set to 60 seconds. The parameter name OP in the module is the output of the module, which is the value of the EH oil temperature 60 seconds ago. The main function of this module is to calculate the lagged value of PV and output the result OP.

[0039] Subtraction block: The module number is SUB08786, the parameter name IN1 in the module is the first input value of the module, the parameter name IN2 in the module is the second input value of the module, and the parameter name OUT in the module is the output of the module. The main function of this module is to calculate the difference between IN1 and IN2 and output it.

[0040] Absolute value module: The module number is ANS18601. The parameter name IN in the module is the input of the module, and the parameter name OUT in the module is the output of the module. The main function of this module is to calculate the absolute value of the analog input and output it.

[0041] Large value selection module: The module number is CMP07071, the parameter name PV1 in the module is the first input value of the module, the parameter name PV2 in the module is the second input value of the module, the parameter name MODE in the module is the comparison mode, MODE is set to large value selection mode, and the parameter name OUT in the module is the output of the module. The main function of this module is to compare PV1 and PV2 and output the comparison result.

[0042] Small value selection module: The module number is CMP07071, the parameter name PV1 in the module is the first input value of the module, the parameter name PV2 in the module is the second input value of the module, the parameter name MODE in the module is the comparison mode, MODE is set to small value selection mode, and the parameter name OUT in the module is the output of the module. The main function of this module is to compare PV1 and PV2 and output the comparison result.

[0043] AND block: The module number is AND426815, the parameter name IN1 in the module is the first input value of the module, the parameter name IN2 in the module is the second input value of the module, the parameter name IN3 in the module is the third input value of the module, the parameter name IN4 in the module is the fourth input value of the module, and the parameter name OUT in the module is the output of the module. The main function of this module is to perform AND operations on four switch inputs.

[0044] Delay block: The module number is TON13743, the parameter name IN in the module is the input of the module, the parameter name TIM in the module is the delay time of the module, and the parameter name OUT in the module is the output of the module. The main function of this module is to output an open signal after a delay of TIM milliseconds.

[0045] like Figure 1 As shown: the control system for EH oil temperature regulation failure warning of the present invention includes four criteria. When all the criteria are met, the final warning result can be pushed.

[0046] The oil temperature of the EH oil tank is collected as the input of the rate block 1, and the value calculated by the rate block 1 is the rate of change of the EH oil temperature. The value calculated by the rate block 1 is used as the input of the absolute value module 2, and the absolute value of the data is calculated by the absolute value module 2. The output of the absolute value module 2 is used as the input of the maximum value selection module 3, and the maximum value selection module 3 is compared with the original constant value 1.5. The value of the output of the maximum value selection module 3 indicates that the rate of change of the oil temperature is greater than 1.5℃ / min. When the oil temperature rate determined by the maximum value selection module 3 is greater than 1.5℃ / min, the output is 1, which serves as the input of the phase and block 10. When the output of the maximum value selection module 3 is 0, it is not used as the input of the phase and block 10. This control logic indicates whether the change of the EH oil temperature affects the internal leakage of the oil system.

[0047] The oil pressure of EH main oil pipe is collected as P n The average oil pressure of the EH oil main pipe is P m They are all connected as the input of the subtractor module 4, and the difference is calculated by the subtractor module 4. The difference calculated by the subtractor module 4 is used as the input of the absolute value module 5, and the absolute value of the data is calculated by the absolute value module 5. The output of the absolute value module 5 is used as the input of the small value selection module 6, and is compared with the original constant 0.3 of the small value selection module 6, indicating that the fluctuation of the EH main pipe oil pressure is within 0.3MPa. When the fluctuation of the EH main pipe oil pressure determined by the small value selection module 6 is within 0.3MPa, the output end is 1, which serves as the input of the phase and block 10. When the output of the large value selection module 3 is 0, it is not used as the input of the phase and block 10. This control logic explains whether the change of the EH main pipe oil pressure affects the internal leakage of the oil system.

[0048] Collect EH oil current as I n and the average value of EH oil current is I n They are all connected as the input of the subtractor module 7, and the difference is calculated by the subtractor module 7. The output of the subtractor module 7 is connected as the input of the absolute value module 8, and the absolute value of the data is calculated by the absolute value module 8. The output of the absolute value module 8 is connected as the input of the minimum value selection module 9, and is compared with the original constant 0.5 of the minimum value selection module 9, indicating that the fluctuation of the EH oil current is within 0.5A. When the fluctuation of the EH oil current determined by the minimum value selection module 9 is within 0.5A, the output is 1, which serves as the input of the phase and block 10. When the output of the minimum value selection module 9 is 0, it is not used as the input of the phase and block 10. This control logic explains whether the change of the current of the EH oil pump affects the internal leakage of the oil system.

[0049] The operation signal B of the EH oil pump is collected as the input end of the phase AND block 10 and connected to the phase AND block 10. When the EH oil pump is running, it serves as the input end of the phase AND block 10. When the EH oil pump is not running, it does not serve as the input end of the phase AND block 10.

[0050] The output end of the large value selection module 3, the output end of the small value selection module 6, the output end of the small value selection module 9 and the output end of module B are used as the input end of the phase AND block 10 and are connected to the phase AND block 10. When the output end of the phase AND block 10 is 1, the output end of the phase AND block 10 is connected to the input end of the delay block 11. The delay block 11 is a delay block with a reset function within 3 minutes. When the output end of the phase AND block 10 is 1 and within 3 minutes, the output end of the delay block 11 is 1. When the output end of the phase AND block 10 is not 1 or exceeds 3 minutes, the output end of the delay block 11 is 0. When the output end of the delay block 11 is 1, the early warning push is satisfied at the same time. According to the logic judgment, the EH oil temperature regulation is pushed to fail. Please check the EH oil cooling water system in time.

Claims

1. A warning system for EH oil temperature regulation failure during operation of a steam turbine EH oil system, characterized in that: include; 1) The AI ​​block of the acquisition module EH oil temperature T is used as the input end of the rate block (1) and is connected to the rate block (1); the output end of the rate block (1) is connected to the input end of the absolute value module (2); the output of the absolute value module (2) and the set value of the maximum value selection module (3) are used as the input end of the maximum value selection module (3) and are connected to the maximum value selection module (3); the output end of the maximum value selection module (3) is connected to the input end of the AND block (10); 2) Collection module EH oil main pipe oil pressure P n Average oil pressure P of AI block and EH oil pipe m The AI ​​block is used as the input end of the subtractor module (4) and is connected to the subtractor module (4); the output end of the subtractor module (4) is connected to the input end of the absolute value module (5); the output end of the absolute value module (5) and the fixed value of the small value selection module (6) are used as the input end of the small value selection module (6) and are connected to each other; the output end of the small value selection module (6) is connected to the input end of the AND block (10); 3) Collection module EH oil current I n The AI ​​block and EH oil average current I m The AI ​​block is used as the input end of the subtractor module (7) and is connected to the subtractor module (7); the output end of the subtractor module (7) is connected to the input end of the absolute value module (8); the output end of the absolute value module (8) and the fixed value of the small value selection module (9) are used as the input end of the small value selection module (9) and are connected; the output end of the small value selection module (9) is connected to the input end of the AND block (10); 4) The output end of the large value selection module (3), the output end of the small value selection module (6), the output end of the small value selection module (9) and the DI block of the acquisition module turbine operation B are all used as the input end of the phase AND block (10) and are connected to each other. The fixed value of the phase AND block (10) and the delay block (11) are all used as the input end of the delay block (11) and are connected to each other. The output end of the delay block (11) is connected to the input end of the early warning result output module (12). According to the above conditions: EH oil pump operation, EH oil pump current, EH oil pump main pipe oil pressure and EH oil temperature change, it is used as the basis for the EH oil temperature regulation failure early warning judgment criterion.

2. The EH oil temperature regulation failure warning system for the steam turbine EH oil system in operation according to claim 1 is characterized in that: The judgment conditions for the EH oil temperature regulation failure warning include: the difference between the EH oil current and the EH average current needs to be within the normal range, the difference between the EH oil mother pipe pressure and the EH average mother pipe pressure needs to be within the normal range, the rate of change of the EH oil temperature is greater than the set value and the EH oil pump is running. All conditions in the control logic need to be met to warn of the EH oil temperature regulation failure.

3. A control method for an EH oil temperature regulation failure warning system under operation of a steam turbine EH oil system according to claim 1 or 2, characterized in that: The steps include: The oil temperature of the EH oil tank is collected as the input of the rate block (1). The value calculated by the rate block (1) is the change rate value of the EH oil temperature. The value calculated by the rate block (1) is used as the input of the absolute value module (2). The absolute value module (2) calculates the absolute value of the data. The output of the absolute value module (2) is used as the input of the maximum value selection module (3). The maximum value selection module (3) has an original constant value of 1.5, and the output value of the maximum value selection module (3) is compared with the original constant value 1.

5. The value of the output of the maximum value selection module (3) indicates that the change rate of the oil temperature is greater than 1.5°C / min. If the oil temperature rate determined by the maximum value selection module (3) is greater than 1.5°C / min, the output is 1 and is used as the input of the phase and block (10). If the output of the maximum value selection module (3) is 0, it is not used as the input of the phase and block (10). This control logic indicates whether the change of the EH oil temperature affects the internal leakage of the oil system. The oil pressure of EH main oil pipe is collected as P n The average oil pressure of the EH oil main pipe is P m They are all used as the input end of the subtractor module (4) and connected, and the difference is calculated by the subtractor module (4). The difference calculated by the subtractor module (4) is used as the input end of the absolute value module (5). The absolute value of the data is calculated by the absolute value module (5). The output end of the absolute value module (5) is used as the input end of the small value selection module (6). It is compared with the original constant 0.3 of the small value selection module (6). It means that the fluctuation change of the oil pressure of the EH main pipe is within 0.3MPa. If the fluctuation change of the oil pressure of the EH main pipe determined by the small value selection module (6) is within 0.3MPa, the output end is 1, which is used as the input end of the phase and block (10). If the output end of the large value selection module (3) is 0, it is not used as the input end of the phase and block (10). This control logic indicates whether the change of the oil pressure of the EH main pipe affects the internal leakage of the oil system. Collect EH oil current as I n and the average value of EH oil current is I n They are all used as input ends of the subtractor module (7) and connected to each other, and the difference is calculated by the subtractor module (7). The output end of the subtractor module (7) is used as the input end of the absolute value module (8) and connected to each other, and the absolute value of the data is calculated by the absolute value module (8). The output end of the absolute value module (8) is used as the input end of the small value selection module (9) and connected to each other, and compared with the original constant 0.5 of the small value selection module (9), indicating that the fluctuation change of the EH oil current is within 0.5A, if the fluctuation change of the EH oil current determined by the small value selection module (9) is within 0.5A, the output end is 1, and is used as the input end of the phase and block (10). If the output end of the small value selection module (9) is 0, it is not used as the input end of the phase and block (10). This control logic indicates whether the change of the current of the EH oil pump affects the internal leakage of the oil system; Collecting the operation signal B of the EH oil pump as the input end of the phase AND block (10), connected to the phase AND block (10), when the EH oil pump is running, it serves as the input end of the phase AND block (10), and when the EH oil pump is not running, it does not serve as the input end of the phase AND block (10); The output end of the large value selection module (3), the output end of the small value selection module (6), the output end of the small value selection module (9) and the output end of module B are used as the input end of the phase AND block (10) and are connected to the phase AND block (10). When the output end of the phase AND block (10) is 1, the output end of the phase AND block (10) is connected to the input end of the delay block (11). The delay block (11) is a delay block with a reset function within 3 minutes. When the output end of the phase AND block (10) is 1 and within 3 minutes, the output end of the delay block (11) is 1. When the output end of the phase AND block (10) is not 1 or exceeds 3 minutes, the output end of the delay block (11) is 0. When the output end of the delay block (11) is 1, the early warning push is satisfied at the same time. According to the logic judgment, the EH oil temperature regulation failure is pushed. Please check the EH oil cooling water system in time.

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