A method for offline verification of control function of steam turbine main turning gear control cabinet

Abstract

The present invention belongs to the field of maintenance technology, and specifically relates to an offline verification method for the control function of a main turning gear control cabinet of a steam turbine. The red test lead and the black test lead of the No. 1 signal generator are connected to the signal terminals of the turbine rotor speed detector P1 and the turbine rotor speed detector P2 respectively; the output is started, and the turbine rotor speed detector P1 and the turbine rotor speed detector P2 display 12.9RPM; the red test lead and the black test lead of the No. 2 signal generator are connected to the signal terminal of the main turning gear motor speed detector P3 respectively; the disengagement signal terminal of the main turning gear disengagement position switch S2 is short-circuited; the main turning gear start command terminal is short-circuited with a short-circuit wire; the output frequency of the No. 1 signal generator is reduced until the turbine rotor speed detector P1 displays ENGAGE@7.5, and the No. 2 signal generator output is started, and the main turning gear motor speed detector P3 is observed to display 8.3RPM. The present invention can effectively avoid the verification work of the controller that can only be done in the turbine run-up or shutdown window.

Description

Technical Field

[0001] The invention belongs to the technical field of maintenance, and in particular relates to an off-line verification method for control functions of a main turning gear control cabinet of a steam turbine. Background Art

[0002] The French ALSTOM technology half-speed nuclear power steam turbine introduced by Oriental Steam Turbine Co., Ltd. has been applied to many million-kW nuclear power units in China. Its main turning gear equipment adopts the electro-hydraulic operated low-speed automatic turning gear produced by SSS.

[0003] The main turning gear device is mainly composed of turning gear motor, hydraulic coupling, reduction clutch, turning gear and other main components, as well as main turning gear controller, soft starter, solenoid valve, speed detector, meshing / disengaging position switch and other auxiliary components. When the turbine gradually slows down to 7.4 rpm, the main turning gear controller controls the oil supply solenoid valve to open, and the meshing power oil enters the thrust annular chamber through the solenoid valve and pushes the clutch pinion to move along the spiral slideway in the meshing direction, so that the phase gear assembled on the pinion contacts the end face of the turning gear. When the turning gear rotates so that the gears and tooth grooves of the phase gear and the turning gear are aligned with each other, the pinion realizes preliminary meshing with the turning gear under the push of the meshing power oil. Subsequently, the solenoid valve loses power and closes, the meshing power oil is cut off, and the torque on the spiral slideway caused by the turning gear rotation causes the turning gear pinion to continue to move axially, realizing full meshing of the clutch, the meshing position switch is actuated, the turning gear is put into normal operation, driving the turbine shaft to rotate, and the speed is maintained at 8.3 rpm. The speed detectors include three, namely, turbine rotor speed detectors P1 and P2 and main turning gear motor speed detector P3, with a speed ratio of 116HZ=60RPM. The main turning gear disengagement and engagement position switches S2 and S3 are used to detect whether the clutch is disengaged and engaged, respectively. The above signals are fed back to the turning gear controller through the terminal block. The main turning gear controller is the core control element of the entire turning gear device, controlling every step of the operation of the entire turning gear device. The signals collected by each detector (P1, P2, P3, S2, S3) are collected to determine the state of the turning gear, and the execution signal of each step is issued to control the start and stop of the turning gear motor and the on and off of the solenoid valve, and to exchange turning gear operation signals with the power station control system. Various electrical interfaces of the turning gear are provided to display the turning gear operation status and fault codes.

[0004] The main function of the main turning device of the steam turbine is to continuously turn the turbine after the unit is shut down, which can ensure that the rotor is heated evenly and avoid the rotor from bending and deforming due to excessive temperature after the turbine is shut down. At present, the main turning controller has the following problems when used:

[0005] During the shutdown process of the steam turbine, when the speed of the steam turbine drops to about 20rpm, the P1 card in the main turntable control cabinet is prone to jamming. The controller fails and cannot provide subsequent related signal collection and command issuance, resulting in the main turntable being unable to operate normally when the steam turbine drops to 8RPM. Since the controller requires more signals to be put into operation and the relevant operation signals must be triggered during the shutdown period of the steam turbine, there is no corresponding window for maintenance personnel to verify after handling the fault or replacing spare parts. At present, if similar situations occur in various power plants, they can only shut down for verification after the steam turbine is restarted or wait until the next shutdown of the steam turbine to verify again. Since the start or stop of the steam turbine involves many systems and personnel, the verification work is relatively difficult. During the overhaul, it will have a greater impact on the entire overhaul period and cause economic losses to the company. If the verification is unsuccessful, it may even cause malicious incidents such as bending of the turbine main shaft due to the unavailability of the turntable system. Summary of the invention

[0006] The purpose of the present invention is to provide a method for offline verification of the control function of the SSS main turntable control cabinet of a nuclear power steam turbine without actually driving the main shaft of the steam turbine, which can effectively avoid the verification work of the controller only in the steam turbine start-up or shutdown window, save manpower and time during the steam turbine start-up or shutdown process, advance the power generation time of the power plant, improve the economic benefits of the power plant, avoid the risk of damage to the main shaft of the steam turbine, and save company costs.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for offline verification of control function of a steam turbine main turning gear control cabinet comprises the following steps:

[0009] Step 1: Connect the red and black test leads of signal generator No. 1 to the signal terminals of turbine rotor speed detector P1 and turbine rotor speed detector P2 respectively; start the output, and turbine rotor speed detector P1 and turbine rotor speed detector P2 display 12.9RPM;

[0010] Step 2: Connect the red and black test leads of signal generator No. 2 to the signal terminals of the main turning vehicle motor speed detector P3 respectively;

[0011] Step 3: Use a shorting wire to short-circuit the disengagement signal terminal of the main turning gear disengagement position switch S2; use a shorting wire to short-circuit the main turning gear start command terminal;

[0012] Step 4: Reduce the output frequency of signal generator No. 1 until the turbine rotor speed detector P1 displays ENGAGE@7.5, start the output of signal generator No. 2, and observe that the main turning motor speed detector P3 displays 8.3RPM; manually reduce the output frequency of signal generator No. 1 again until the turbine rotor speed detector P1 displays 7.4RPM; observe that the turbine rotor speed detector P1 should display VALUE ON;

[0013] Step 5. Pull out the short-circuit wire of the disengagement signal terminal of the main turning gear disengagement position switch S2; short-circuit the engagement signal terminal of the main turning gear engagement position switch S3, and observe that the turbine rotor speed detector P1 should display ETG RUNNING; determine that the turning gear start-up during the offline simulated shutdown and speed reduction process has been successfully implemented.

[0014] The model of signal generator No. 1 is FLUKE744.

[0015] Step 1: Set the voltage to 9V, rectangular wave, 25Hz, step size 0.1Hz, and start output.

[0016] The model of signal generator No. 2 is FLUKE744.

[0017] Step 2: Set the voltage to 9V, rectangular wave, 12.5Hz.

[0018] Step 3: Use a pluggable short-circuit wire to short-circuit the disengagement signal terminal of the main turntable disengagement position switch S2.

[0019] VALUE ON means the fuel supply valve is open.

[0020] ETG RUNNING means the cranking is running.

[0021] The beneficial effects achieved by the present invention are:

[0022] The above test method can be used to verify the offline cranking function. After the subsequent debugging of the main cranking control cabinet and the replacement of important spare parts such as the P1 card, the cranking start-up during the shutdown and speed reduction process can be simulated by the above method and the engagement at 7.4RPM can be used to verify the control cabinet function offline. The fault point of the main cranking control cabinet can be identified and processed in advance to ensure that the turbine main shaft is started successfully at one time, thereby effectively shortening the debugging period or overhauling the main line to save manpower and time during the turbine start-up or shutdown process, advance the power generation time of the power plant, improve the economic benefits of the power plant, avoid the risk of damage to the turbine main shaft, and save the company's costs. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to specific embodiments.

[0024] The method for offline verification of the control function of the main cranking gear control cabinet of the steam turbine of the present invention comprises the following steps, which can offline simulate the cranking gear start-up and engagement at 7.4RPM during the shutdown and speed reduction process.

[0025] Step 1: Connect the red and black test leads of signal generator No. 1 (model FLUKE744) to the signal terminals of turbine rotor speed detector P1 and turbine rotor speed detector P2 respectively; set the voltage to 9V, rectangular wave, 25Hz, step length 0.1Hz, start the output, and the turbine rotor speed detector P1 and turbine rotor speed detector P2 display 12.9RPM;

[0026] Step 2. Connect the red and black test leads of signal generator No. 2 (model FLUKE744) to the signal terminal of the main turning vehicle motor speed detector P3 respectively, set the voltage to 9V, rectangular wave, 12.5Hz (only setting, do not start the output);

[0027] Step 3: Use a pluggable wiring to short-circuit the disengagement signal terminal of the main turning car disengagement position switch S2; use a shorting wire to short-circuit the main turning car start command terminal;

[0028] Step 4: Reduce the output frequency of signal generator No. 1 until the turbine rotor speed detector P1 displays "ENGAGE@7.5", start the output of signal generator No. 2, and observe that the main turning motor speed detector P3 displays 8.3RPM; manually reduce the output frequency of signal generator No. 1 again until the turbine rotor speed detector P1 displays 7.4RPM; observe that the turbine rotor speed detector P1 should display "VALUE ON" (oil supply valve is open);

[0029] Step 5: Pull out the disengagement signal terminal short-circuit wire of the main turning gear disengagement position switch S2; short-circuit the engagement position signal terminal of the main turning gear engagement position switch S3, and observe that the turbine rotor speed detector P1 should display "ETG RUNNING" (turning gear running); it can be judged that the turning gear start-up during the offline simulated shutdown and speed reduction process has been successfully implemented.

Claims

1. A method for offline verification of control function of a steam turbine main turning gear control cabinet, characterized in that: The following steps are included: Step 1: Connect the red and black test leads of signal generator No. 1 to the signal terminals of turbine rotor speed detector P1 and turbine rotor speed detector P2 respectively; start the output, and turbine rotor speed detector P1 and turbine rotor speed detector P2 display 12.9RPM; Step 2: Connect the red and black test leads of signal generator No. 2 to the signal terminals of the main turning vehicle motor speed detector P3 respectively; Step 3: Use a shorting wire to short-circuit the disengagement signal terminal of the main turning gear disengagement position switch S2; use a shorting wire to short-circuit the main turning gear start command terminal; Step 4: Reduce the output frequency of signal generator No. 1 until the turbine rotor speed detector P1 displays ENGAGE@7.5, start the output of signal generator No. 2, and observe that the main turning motor speed detector P3 displays 8.3RPM; manually reduce the output frequency of signal generator No. 1 again until the turbine rotor speed detector P1 displays 7.4RPM; observe that the turbine rotor speed detector P1 should display VALUE ON; VALUE ON means the oil supply valve is open; Step 5. Pull out the short-circuit wire of the disengagement signal terminal of the main turning gear disengagement position switch S2; short-circuit the engagement signal terminal of the main turning gear engagement position switch S3, and observe that the turbine rotor speed detector P1 should display ETG RUNNING; determine whether the turning gear start-up during the offline simulated shutdown and speed reduction process is successfully implemented; ETG RUNNING indicates that the turning gear is running.

2. The method for offline verification of control function of main turning gear control cabinet of steam turbine according to claim 1 is characterized in that: The model of signal generator No. 1 is FLUKE744.

3. The method for offline verification of control function of main turning gear control cabinet of steam turbine according to claim 1, characterized in that: Step 1: Set the voltage to 9V, rectangular wave, 25Hz, step size 0.1Hz, and start output.

4. The method for offline verification of control function of main turning gear control cabinet of steam turbine according to claim 1, characterized in that: The model of signal generator No. 2 is FLUKE744.

5. The method for offline verification of control function of main turning gear control cabinet of steam turbine according to claim 1, characterized in that: Step 2: Set the voltage to 9V, rectangular wave, 12.5Hz.

6. The method for offline verification of control function of main turning gear control cabinet of steam turbine according to claim 1, characterized in that: Step 3: Use a pluggable short-circuit wire to short-circuit the disengagement signal terminal of the main turntable disengagement position switch S2.