Fault early warning device and method for tripping electromagnetic valve of steam turbine

Abstract

According to the fault early warning device and method for the tripping electromagnetic valve of the steam turbine, the induced current of the tripping electromagnetic valve loop is obtained through the current transformer, the distributed control system calculates the induced current standard deviation according to the received induced current of the tripping electromagnetic valve, and whether the tripping electromagnetic valve is abnormal or not is judged according to the induced current standard deviation; the fault early warning function of the tripping electromagnetic valve of the steam turbine is realized; according to the device, an original power supply loop of the tripping electromagnetic valve of the steam turbine is not changed, and the induction current in the loop of the tripping electromagnetic valve is monitored by using the non-contact current transformer; when fatigue of a coil of the tripping electromagnetic valve is detected, a fault early warning signal is sent out in time, and after receiving early warning, a power plant operator informs a maintainer to replace the tripping electromagnetic valve, so that safe and stable operation of the generator set is guaranteed, and the safety of the generator set is improved.

Description

Technical Field

[0001] The present application belongs to the field of steam turbine fault warning, and specifically relates to a steam turbine trip solenoid valve fault warning device and method. Background Art

[0002] When the generator set is running, the turbine trip solenoid valve is a normally energized device, generally powered by AC, and has an operating temperature of about 100°C. Since there is no effective means to monitor the fatigue degree of the solenoid valve coil, maintenance can only be carried out by experience or regular replacement, resulting in a waste of resources and increased operating costs; at the same time, due to the high working environment temperature of the trip solenoid valve, some solenoid valve coils may age prematurely, causing the turbine generator set to trip, greatly affecting the safe and stable operation of the generator set. Summary of the invention

[0003] In order to solve the problem that there is no effective means to monitor the fatigue degree of the solenoid valve coil in the prior art, a turbine trip solenoid valve fault warning device and method are proposed to improve the safety of the generator set.

[0004] A turbine trip solenoid valve fault warning device comprises: a current transformer, a distributed control system and a display; the current transformer is used to obtain the induced current of the trip solenoid valve, and send the induced current of the trip solenoid valve to the distributed control system, the distributed control system calculates the standard deviation of the induced current according to the received induced current of the trip solenoid valve, and judges whether the trip solenoid valve is abnormal according to the standard deviation of the induced current, and generates a warning signal if it is abnormal, and sends the warning signal to the display; the display is used to display the received warning signal.

[0005] Beneficial Effects

[0006] The present application discloses a steam turbine trip solenoid valve fault warning device and method, which obtains the induced current of the trip solenoid valve circuit through a current transformer, and the distributed control system calculates the induced current standard deviation according to the received trip solenoid valve induced current, and determines whether the trip solenoid valve is abnormal according to the induced current standard deviation, thereby realizing the steam turbine trip solenoid valve fault warning function; the present application discloses a steam turbine trip solenoid valve fault warning device, which does not change the original power supply circuit of the steam turbine trip solenoid valve, and monitors the induced current in the trip solenoid valve circuit by using a non-contact current transformer; when fatigue of the trip solenoid valve coil is detected, a fault warning signal is issued in time, and after receiving the warning, the power plant operating personnel notify the maintenance personnel to replace the trip solenoid valve, thereby ensuring the safe and stable operation of the generator set and improving the safety of the generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a structural diagram of a steam turbine trip solenoid valve fault warning device according to a specific implementation method of the present application;

[0008] Figure 2 It is a time-induced current curve and a time-standard deviation curve of a steam turbine trip solenoid valve fault warning method according to a specific implementation mode of the present application;

[0009] Figure 3 This is a flow chart of a turbine trip solenoid valve fault warning method according to a specific implementation method of the present application. DETAILED DESCRIPTION

[0010] Specific implementation method 1: The following will be combined Figures 1 to 3 , describing the present embodiment, a turbine trip solenoid valve fault warning device, comprising: a current transformer, a distributed control system and a display; the current transformer is used to obtain the induced current of the trip solenoid valve, and send the induced current of the trip solenoid valve to the distributed control system (DCS system), the distributed control system calculates the induced current standard deviation according to the received induced current of the trip solenoid valve, and determines whether the trip solenoid valve is abnormal according to the induced current standard deviation, and generates a warning signal if it is abnormal, and sends the warning signal to the display; the display is used to display the received warning signal.

[0011] Specifically, Figure 1 As shown in the figure, the dotted box is divided into the turbine trip solenoid valve fault warning device requested by the operator. The current transformer is set outside the trip solenoid valve power supply circuit, and the original trip solenoid valve power supply circuit is not changed. After the turbine is shut down, the turbine trip switch is closed. When the turbine generator set is running, the trip solenoid valve is always energized. The current transformer transmits the induced current data to the distributed control system in real time. The distributed control system compiles the fault warning method logic and sends out a fault warning signal in time when the trip solenoid valve coil fatigue is detected. After receiving the warning, the power plant operator notifies the maintenance personnel to replace the trip solenoid valve to ensure the safe and stable operation of the generator set.

[0012] Furthermore, the distributed control system includes a distributed control data acquisition card and a distributed controller. The distributed control data acquisition card (DCS data acquisition card) is used to receive the trip solenoid valve induced current sent by the current transformer, and send the trip solenoid valve induced current to the distributed controller (DCS controller); the distributed controller is used to obtain the induced current standard deviation based on the received trip solenoid valve induced current, and determine whether the trip solenoid valve is faulty based on the induced current standard deviation. If so, an early warning signal is generated and the early warning signal is sent to the display.

[0013] Furthermore, the turbine tripping solenoid valve fault warning device also includes a mobile terminal, which is communicatively connected to the distributed controller. The distributed controller sends the generated warning signal to the mobile terminal, and the mobile terminal issues a warning based on the received warning signal.

[0014] Furthermore, the method for the decentralized controller to obtain the standard deviation of the induced current according to the received induced current of the tripping solenoid valve is as follows: collecting n induced currents of the tripping solenoid valves, with a fixed time t between every two adjacent induced currents of the tripping solenoid valves, and calculating the standard deviation S of the induced currents of the n tripping solenoid valves;

[0015] Among them, x i is the induced current of the i-th tripping solenoid valve, is the average value of the induced current of n tripping solenoid valves, n is a positive integer, i∈n.

[0016] Specifically, Figure 2 As shown, the induced current data of the tripping solenoid valve at 1800 time points in 30 minutes (obtained once per second) are selected to draw the time-induced current curve, 20 continuous induced current points are selected to calculate the standard deviation S of the induced current of the tripping solenoid valve in real time, and the time-standard deviation curve of the induced current of the tripping solenoid valve is drawn.

[0017] Furthermore, the method for judging whether the tripping solenoid valve is faulty based on the standard deviation of the induced current is as follows: setting a fault warning threshold, judging whether the standard deviation of the induced current reaches the fault warning threshold, if so, the tripping solenoid valve is faulty, otherwise, the tripping solenoid valve is not faulty.

[0018] Specifically, Figure 2 As shown, the data shows that when the induced current is stable, the standard deviation of the induced current of the tripping solenoid valve is very small, fluctuating around 1%; when the fault warning threshold is set to 6%, the induced current fluctuates abnormally around 1098s, and the standard deviation increases to 7%. The distributed controller generates a solenoid valve fault warning signal and sends it to the display and mobile terminal to remind the power plant maintenance personnel to replace the tripping solenoid valve in time; although the induced current quickly returned to stability after the fluctuation, and the standard deviation returned to around 1%, the solenoid valve coil failed after a period of time, and the induced current fluctuated greatly and then completely disappeared, and the standard deviation increased to 16%, proving the effectiveness of the warning signal.

[0019] Furthermore, the induced currents of n tripping solenoid valves are collected, and the fixed time t between the induced currents of every two adjacent tripping solenoid valves is in the range of 0 to 1 second.

[0020] Furthermore, the value range of the obtained trip solenoid valve induced current number n is 20 to 50.

[0021] Specific implementation method 2: A turbine trip solenoid valve fault early warning method, comprising:

[0022] Step 1: Obtain the induced current of the tripping solenoid valve, and calculate the induced current standard deviation according to the induced current of the tripping solenoid valve;

[0023] Step 2: Determine whether the tripping solenoid valve is abnormal based on the standard deviation of the induced current. If so, generate an early warning signal and issue an early warning

[0024] Furthermore, the method for calculating the standard deviation of the induced current based on the induced current of the tripping solenoid valve is: collecting n induced currents of the tripping solenoid valves, with a fixed time t between every two adjacent induced currents of the tripping solenoid valves, and calculating the standard deviation of the n induced currents of the tripping solenoid valves.

[0025] Furthermore, the method for judging whether the tripping solenoid valve is abnormal based on the standard deviation of the induced current is: setting a fault warning threshold, judging whether the standard deviation of the induced current reaches the fault warning threshold, if so, the tripping solenoid valve is abnormal, otherwise, the tripping solenoid valve is normal.

Claims

1. A steam turbine trip solenoid valve fault warning device, characterized in that: include: Current transformers, distributed control systems and displays; The current transformer is used to obtain the induced current of the tripping solenoid valve, and send the induced current of the tripping solenoid valve to the distributed control system. The distributed control system calculates the standard deviation of the induced current based on the received induced current of the tripping solenoid valve, and determines whether the tripping solenoid valve is abnormal based on the standard deviation of the induced current. If so, an early warning signal is generated and sent to the display; the display is used to display the received early warning signal.

2. A turbine trip solenoid valve fault warning device according to claim 1, characterized in that: The distributed control system comprises a distributed control data acquisition card and a distributed controller, wherein the distributed control data acquisition card is used to receive the trip solenoid valve induced current sent by the current transformer, and send the trip solenoid valve induced current to the distributed controller; The distributed controller is used to obtain the standard deviation of the induced current according to the received induced current of the tripping solenoid valve, and judge whether the tripping solenoid valve has a fault according to the standard deviation of the induced current. If so, an early warning signal is generated and sent to the display.

3. A turbine trip solenoid valve fault warning device according to claim 2, characterized in that: The method for the decentralized controller to obtain the standard deviation of the induced current according to the received induced current of the tripping solenoid valve is as follows: collecting n induced currents of the tripping solenoid valves, with a fixed time t between each two adjacent induced currents of the tripping solenoid valves, and calculating the standard deviation S of the induced currents of the n tripping solenoid valves; Among them, x i is the induced current of the i-th tripping solenoid valve, is the average value of the induced current of n tripping solenoid valves, n is a positive integer, i∈n.

4. A turbine trip solenoid valve fault warning device according to claim 3, characterized in that: The method for judging whether the tripping solenoid valve is faulty based on the standard deviation of the induced current is as follows: setting a fault warning threshold, judging whether the standard deviation of the induced current reaches the fault warning threshold, if so, the tripping solenoid valve is faulty, if not, the tripping solenoid valve is not faulty.

5. A turbine trip solenoid valve fault warning device according to claim 3, characterized in that: The fixed time t between the induced currents of every two adjacent tripping solenoid valves is in the range of 0 to 1 second.

6. A turbine trip solenoid valve fault warning device according to claim 3, characterized in that: The value range of the obtained trip solenoid valve induced current number n is 20 to 50.

7. A turbine trip solenoid valve fault warning device according to claim 1, characterized in that: It also includes a mobile terminal, which is connected to the decentralized system for communication. The decentralized system sends the generated warning signal to the mobile terminal, and the mobile terminal issues a warning based on the received warning signal.

8. A method for early warning of a steam turbine trip solenoid valve fault, characterized in that: include: Step 1: Obtain the induced current of the tripping solenoid valve, and calculate the induced current standard deviation according to the induced current of the tripping solenoid valve; Step 2: Determine whether the tripping solenoid valve is abnormal based on the standard deviation of the induced current. If so, generate a warning signal and issue a warning.

9. A method for early warning of a steam turbine trip solenoid valve fault according to claim 8, characterized in that: The method for calculating the standard deviation of the induced current based on the induced current of the tripping solenoid valve is as follows: collecting n induced currents of the tripping solenoid valves, with a fixed time t between every two adjacent induced currents of the tripping solenoid valves, and calculating the standard deviation of the n induced currents of the tripping solenoid valves.

10. A method for early warning of a steam turbine trip solenoid valve fault according to claim 9, characterized in that: The method for judging whether the tripping solenoid valve is abnormal based on the standard deviation of the induced current is as follows: setting a fault warning threshold, judging whether the standard deviation of the induced current reaches the fault warning threshold, if so, the tripping solenoid valve is abnormal, otherwise, the tripping solenoid valve is normal.

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