CN108661729B

CN108661729B - Hydraulic barring control loop provided with fault protection device

Info

Publication number: CN108661729B
Application number: CN201710209255.2A
Authority: CN
Inventors: 成涛
Original assignee: Shanghai Meishan Iron and Steel Co Ltd
Current assignee: Shanghai Meishan Iron and Steel Co Ltd
Priority date: 2017-03-31
Filing date: 2017-03-31
Publication date: 2021-04-06
Anticipated expiration: 2037-03-31
Also published as: CN108661729A

Abstract

The invention relates to a hydraulic barring control circuit provided with a fault protection device, which is characterized by comprising a timing controller, a DCS control system, a barring electromagnetic valve connected with the DCS, a barring action simulation component and a barring action component, wherein the timing controller is connected with the DCS; the device skillfully utilizes the electromagnetic pushing mechanism as the displacement of the simulation turning gear stroke indicating rod, and simultaneously sets two identical approach switch detection loops as the hot standby when the main loop breaks down. The relay automatic switching function is utilized to realize the successful disturbance-free rapid automatic switching of the fault control circuit and the analog control circuit, the normal work of the barring system is realized, the safe and stable operation of the turbo generator unit is guaranteed, and meanwhile, precious time is won for the maintainers to solve the fault problem in time.

Description

Hydraulic barring control loop provided with fault protection device

Technical Field

The invention relates to a control circuit, in particular to a hydraulic barring control circuit with a fault protection device, and belongs to the technical field of motor control.

Background

At present, a hydraulic barring control system is very commonly applied to a turbine unit, and the hydraulic barring control system drives an oil cylinder actuating mechanism to act by using a hydraulic pulse electromagnetic valve, drives a unit large shaft to rotate for a certain angle by using a turbine worm, detects barring action conditions on site by two paths of proximity switches, converts action signals into switching values and sends the switching values to a DCS (distributed control system) to realize closed-loop control of barring actions; and then, the interval time is set according to a control system program to drive the unit to turn the gear to move at intervals, so that the large shaft is uniformly heated, and the irreversible fault caused by deformation and bending is avoided. According to the practical performance of hydraulic barring of 4 Siemens steam turbines in a plum steel thermal power plant, the barring system has failure control of the unit barring due to the fact that a proximity switch fails or a control circuit fails for many times, does not act, and seriously influences normal starting or safe stopping of the unit. The overhaul personnel spend a lot of time from checking the fault point to solving the problem, and the invention of a device for simulating the barring action in real time is very necessary from the view point of the unit safety, and the signal of the simulated action can be sent to the DCS control system in real time, so that the normal operation of the barring is ensured, and the unit safety is ensured.

Disclosure of Invention

The invention aims at the technical problems in the prior art, provides a hydraulic barring control circuit provided with a fault protection device, the technical proposal simulates a hydraulic barring action travel indicating mechanism and a fault relay automatic switching loop, utilizes the simulated hydraulic barring action mechanism, is additionally provided with a proximity switch for detecting, converting and transmitting switching value signals to a DCS control system, when a fault occurs in a proximity switch or a control circuit in a normal hydraulic barring control system, a barring action signal cannot be timely sent to the control system to cause a fault condition of control failure, a fault point triggers a simulation hydraulic barring mechanism to act, meanwhile, a standby control loop is switched to be used through a relay loop in a non-disturbance mode, so that the normal work of a steam turbine barring system is guaranteed, and the safety of a large shaft after normal starting and normal stopping of a unit is guaranteed.

In order to achieve the above object, according to the technical solution of the present invention, a hydraulic barring control circuit provided with a fault protection device is characterized in that the control circuit includes a timing controller, a DCS control system, a barring solenoid valve connected to the DCS, a simulated barring action component, and a barring action component.

As an improvement of the invention, the barring action assembly comprises a first barring action proximity switch, a second barring action proximity switch, a barring travel indicating rod, an oil return port, a servo oil cylinder, a piston, an oil inlet, a worm gear, a unit large shaft, a first signal converter, a second signal converter, a relay K4 normally closed contact, a relay K3 normally closed contact, a DCS contact output and a DCS control system, wherein the unit large shaft is meshed with the worm in a tooth-to-tooth manner, the worm and the piston are rigidly connected in the servo oil cylinder, the barring travel indicating rod is connected with the piston, the two groups of barring action proximity switches are respectively sent to a switching value input point in the DCS control system through the two signal converters and the normally closed contact of the relay K, and the node output in the DCS control system directly controls the barring electromagnetic valve to act through a signal cable, the input and the output of the barring electromagnetic valve are respectively connected with the oil inlet and the oil return port through pipelines.

As an improvement of the invention, a cylindrical barrel is additionally arranged in a displacement section of the barring travel indicating rod, so that a first barring action proximity switch and a second barring action proximity switch are installed conveniently.

As an improvement of the invention, the simulated barring action assembly comprises a first simulated barring action proximity switch, a second simulated barring action proximity switch, a first limit switch, a movable iron core stop block, a second limit switch, a third signal converter, a fourth signal converter, a relay K1 normally open contact, a relay K2 normally open contact, a first DCS switching value input, a DCS switching value falling input, a DCS contact output and an electromagnetic pushing mechanism, and the timing controller is directly connected with the wiring end of the electromagnetic pushing mechanism through a cable.

As an improvement of the invention, a cylindrical barrel is additionally arranged above a movable iron core of the electromagnetic pushing mechanism so as to be convenient for installing a first simulated turning motion proximity switch and a second simulated turning motion proximity switch, and limit switches (23, 26) are additionally arranged at the upper end and the lower end of the other side of the cylindrical barrel.

As an improvement of the invention, the time interval set by the timing controller is that the contact signal is output every 30 seconds to control the action of the electromagnetic pushing mechanism.

As an improvement of the invention, the big shaft of the unit rotates 15 degrees every 30 seconds when the barring gear works normally.

Compared with the prior art, the invention has the advantages that 1) the technical scheme has ingenious and compact integral structure design and lower cost; 2) the technical scheme simulates a barring action travel indicating device to realize real-time position detection of two simulated barring proximity switches, and sends a detection signal to a DCS (distributed control system) through automatic switching to ensure normal work of barring closed-loop control, so that when a proximity switch or a line in a barring control circuit which is normally used on line fails, the detection signal can be automatically switched to the simulated barring control circuit through a fault point alarm circuit; 3) the device utilizes the principle that an electromagnetic pushing mechanism, namely a coil is electrified, and a movable iron core can move up and down to simulate the working condition that a large shaft rotates for a certain angle to drive a stroke indicating rod to move up and down for a certain interval when the barring is in normal work, namely the movable iron core in the electromagnetic pushing mechanism simulates the stroke indicating rod, the electromagnetic pushing mechanism is directly controlled by a timing controller, and the large shaft rotates for 15 degrees every 30 seconds during normal barring, and directly drives the stroke indicating rod vertically connected with the large shaft to move up and down when the large shaft rotates; therefore, the timing controller outputs a contact signal every 30 seconds to directly control the electromagnetic pushing mechanism to act; 4) the technical scheme simulates the action of a stroke indicating rod of a real-time barring on line through an electromagnetic pushing mechanism controlled in a timing mode, and utilizes a detection loop of a proximity switch simulated on line as a hot standby of a normal control loop; 5) The normal work of the turning gear control system is realized through the fault automatic switching of the relay loop, and the safe and stable operation of the steam turbine unit is ensured; through the automatic switching of the analog control, time is won for the fault maintenance of the barring system; a mechanical limit switch is additionally arranged on the electromagnetic pushing mechanism to serve as redundancy of an analog control circuit. Further ensuring the normal work of the barring.

Drawings

FIG. 1 is a schematic view of the normal operation of the barring gear of the present invention;

FIG. 2 is a schematic view of a simulated barring operation;

fig. 3 is a circuit diagram of the automatic switching circuit for simulating turning motion.

Wherein: 1. a first barring action proximity switch, 2, a second barring action proximity switch, 3, a barring travel indicating rod, 4, an oil return port, 5, a servo oil cylinder, 6, a piston, 7, an oil inlet, 8, a worm, 9, a barring electromagnetic valve, 10, a worm wheel, 11, a unit large shaft, 12, a first signal converter, 13, a second signal converter, 14, a relay K4 normally closed contact, 15, a relay K3 normally closed contact, 16, a DCS contact output, 17, a DCS control system, 18, a first DCS switching value input, 19, a second DCS switching value input, 21, a first analog barring action proximity switch, 22, a second analog barring action proximity switch, 23, a first limit switch, 24, a movable iron core, 25, a movable iron core stop, 26, a second limit switch, 27, a third signal converter, 28, a fourth signal converter, 210, a relay K1 normally open contact, the control system comprises relays 211, a K2 normally open contact, 212, a first DCS switching value input, 213, a second DCS switching value input, 214, a DC switching value input, 215, an electromagnetic pushing mechanism, 216, terminals, 218 and a timing controller.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: referring to fig. 1, a hydraulic barring control circuit provided with a fault protection device includes a timing controller, a DCS control system, a barring electromagnetic valve connected to the DCS, a barring action simulation component and a barring action component, where the barring action component includes a first barring action proximity switch 1, a second barring action proximity switch 2, a barring travel indication rod 3, an oil return port 4, a servo cylinder 5, a piston 6, an oil inlet 7, a worm 8, a barring electromagnetic valve 9, a worm wheel 10, a unit main shaft 11, a first signal converter 12, a second signal converter 13, a relay K4 normally closed contact 14, a relay K3 normally closed contact 15, a DCS contact output 16, a DCS control system 17, a first DCS switching value input 18 and a second DCS switching value input 19, the unit main shaft 11 is engaged with the worm 8 in a tooth-to-tooth manner, and the worm 8 is rigidly connected to the piston 6 inside the servo cylinder 5, the barring travel indicating rod 3 is connected with the piston 6, the two groups of barring action proximity switches 1 and 2 are respectively sent to switching value input points 19 and 18 in the DCS control system through two

signal converters

13 and 12 and normally closed

contacts

15 and 14 of the relay K, a node output 16 in the DCS control system directly controls the barring electromagnetic valve 9 to act through a signal cable, and the input and the output of the barring electromagnetic valve are respectively connected with the oil inlet 7 and the oil return port 4 through pipelines. And a cylindrical barrel is additionally arranged in the displacement interval of the barring travel indicating rod so as to facilitate the installation of the barring action proximity switch 1 and the barring action proximity switch 2. The simulated barring action assembly comprises a first simulated barring action proximity switch 21, a second simulated barring action proximity switch 22, a first limit switch 23, a movable iron core 24, a movable iron core stop 25, a second limit switch 26, a third signal converter 27, a signal converter 28, a normally-open contact 210 of a relay K1, a normally-open contact 211 of a relay K2, a first DCS switching value input 212, a second DCS switching value input 213, a DCS joint output 214, an electromagnetic pushing mechanism 215 and a terminal 216, wherein the electromagnetic pushing mechanism 215 is fixedly arranged on one side of a field barring control system, the movable iron core stop 25 is fixedly connected with the movable iron core 24, the two groups of simulated barring

action proximity switches

21 and 22 are respectively sent to the

switching value inputs

212 and 213 of the DCS control system 17 through the two groups of

signal converters

27 and 28 and the normally-

open contacts

210 and 211 of the relay K, the joint output 16 of the DCS control system acts through a direct cable control panel barring electromagnetic valve 9, the timing controller 218 is directly connected with the terminal 216 of the electromagnetic pushing mechanism through a cable, a cylindrical barrel is additionally arranged above the movable iron core 24 of the electromagnetic pushing mechanism 215 so as to be convenient for installing the

proximity switches

21 and 22 simulating the turning motion, and

limit switches

23 and 26 are additionally arranged at the upper end and the lower end of the other side of the cylindrical barrel. The time interval set by the timing controller is that a contact signal is output every 30 seconds to control the action of the electromagnetic pushing mechanism, and the large shaft of the unit rotates 15 degrees every 30 seconds when the barring gear normally works. Referring to fig. 3, the simulated barring action automatic switching circuit diagram is used, once any one group of barring action proximity switches in the normal barring control system fails or a control cable fails, the DCS barring fault point gives an alarm and immediately triggers the timing controller and the relay K to get electricity to act. After the timing controller is powered on, a contact signal is output every 30 seconds according to a set interval time to control the electromagnetic pushing mechanism to act, namely the starting of the simulated turning gear; the relay K coil is electrified, then relay normally closed contact K3, K4 become normally open, normal barring control circuit breaks off promptly, relay K2 normally open contact K1, K2 are closed, simulate barring control circuit to open promptly, through autogenous cutting, barring control normal operating.

The working process is as follows:

referring to fig. 1-3, when the barring works normally, the DCS control system receives a position detection signal of the barring action proximity switch 1, immediately outputs a switch quantity to control the power-on action of the barring electromagnetic valve, at the moment, high-pressure hydraulic oil is turned on to drive the servo oil cylinder to act, the large shaft of the unit rotates by 15 degrees, at the moment, the barring stroke indicating rod moves upwards, the barring action proximity switch 2 detects the displacement of the stroke indicating rod, and a real-time detection signal is sent to the DCS to perform closed-loop control of the barring work.

When the installation position of a proximity switch in a normally working barring control system is inaccurate and the displacement of a stroke indicating rod cannot be detected, the direct fault failure of the barring control is caused; or the turning control is stopped directly due to the faults of the proximity switch and the control circuit, at the moment, the turning control is automatically put in through the DCS fault, the timing controller is electrified to work, and the electromagnetic pushing mechanism acts once according to the set interval time of 30 seconds; when the coil of the relay K is electrified, normally closed contacts K3 and K4 of the relay K are normally opened, namely a normal barring control circuit is disconnected; normally open contacts K1 and K2 of the relay K are closed, namely, the simulated barring control loop is opened. At the moment, the simulated barring control circuit takes over the normal barring control circuit to work, the two ways of simulated barring action proximity switches 1 and 2 respectively detect the displacement of the movable iron core of the electromagnetic pushing mechanism, and send signals to the DCS control system in real time to carry out normal control of barring. When the simulation barring proximity switch or the control circuit goes wrong, the barring still can not normally work after the automatic switch is successful, at the moment, an upper mechanical limit switch and a lower mechanical limit switch in a cylindrical barrel additionally arranged above the electromagnetic pushing mechanism are used as a last standby circuit, and the switching value generated by the triggering of the limit switches is pushed by the displacement of the movable iron core and is directly sent to the switching value input end of the DCS control system through the circuit, so that the barring electromagnetic valve is triggered to act, and the normal work of the barring system is ensured.

In summary, the technical device skillfully uses the electromagnetic pushing mechanism as the displacement of the simulated barring travel indicating rod, and simultaneously sets the same two approach switch detection loops as the hot standby when the main loop breaks down. The relay automatic switching function is utilized to realize the successful disturbance-free rapid automatic switching of the fault control circuit and the analog control circuit, the normal work of the barring system is realized, the safe and stable operation of the turbo generator unit is guaranteed, and meanwhile, precious time is won for the maintainers to solve the fault problem in time.

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.

Claims

1. A hydraulic barring control circuit provided with a fault protection device is characterized by comprising a timing controller, a DCS control system, a barring electromagnetic valve (9), a simulated barring action component and a barring action component; the jigger action assembly comprises a first jigger action proximity switch (1), a second jigger action proximity switch (2), a jigger travel indicating rod (3), an oil return opening (4), a servo oil cylinder (5), a piston (6), an oil inlet (7), a worm (8), a worm wheel (10), a unit large shaft (11), a first signal converter (12), a second signal converter (13), a relay K4 normally closed contact (14), a relay K3 normally closed contact (15) and a DCS contact output I (16), a first DCS switching value input (18) and a second DCS switching value input (19), wherein the unit large shaft is meshed with the worm teeth in a tooth-to-tooth manner, the worm and the piston are rigidly connected in the servo oil cylinder, the jigger travel indicating rod is connected with the piston, the first jigger action proximity switch is sent to the second switching value input through the second signal converter and the relay K3 normally closed contact, the second turning motion approach switch is sent to the first DCS switching value input through the first signal converter and a normally closed contact of a relay K4,

a DCS contact in the DCS control system outputs a signal cable to directly control the turning electromagnetic valve to act, and the input and the output of the turning electromagnetic valve are respectively connected with the oil inlet and the oil return port through pipelines; a cylindrical barrel is additionally arranged in a displacement interval of the barring travel indicating rod so as to facilitate installation of a first barring action proximity switch (1) and a second barring action proximity switch (2); the simulation turning motion assembly comprises a first simulation turning motion proximity switch (21), a second simulation turning motion proximity switch (22), a first limit switch (23), a movable iron core (24), a movable iron core stop block (25), a second limit switch (26), a third signal converter (27), a fourth signal converter (28), a relay K1 normally open contact (210), a relay K2 normally open contact (211), a third DCS switching value input (212), a fourth DCS switching value input (213), a second DCS contact output (214), an electromagnetic pushing mechanism (215) and a wiring terminal (216), wherein the electromagnetic pushing mechanism (215) is fixedly installed on one side of a field turning control system, the movable iron core stop block (25) is fixedly connected with the movable iron core (24), and the first simulation turning motion proximity switch is sent to the fourth switching value input through the third signal converter and the relay K2 normally open contact, the second simulation barring action proximity switch sends to third DCS switching value input again through fourth signal converter and relay K1 normally open contact, and DCS control system contact output directly controls the barring solenoid valve action through the cable, and timing controller directly is connected with the wiring end of electromagnetism pushing mechanism through the cable.

2. The hydraulic barring control circuit provided with the fault protection device according to claim 1 is characterized in that a cylindrical barrel is additionally arranged above a movable iron core of the electromagnetic pushing mechanism so as to install a first simulated barring action proximity switch (21) and a second simulated barring action proximity switch (22), and limit switches (23, 26) are additionally arranged at the upper end and the lower end of the other side of the cylindrical barrel.

3. The hydraulic barring control circuit provided with the fault protection device according to claim 2, wherein the timing controller sets the time interval to output the contact signal to control the electromagnetic pushing mechanism to act every 30 seconds.

4. The hydraulic barring control circuit provided with the fault protection device according to claim 2 or 3, wherein the unit main shaft rotates 15 degrees every 30 seconds when the barring is in normal operation.