Manual emergency shutdown control loop of steam turbine

Abstract

The utility model discloses a manual emergency shutdown control loop for a steam turbine, which comprises an A-path PLC (Programmable Logic Controller), an odd-number relay module, an odd-number electromagnetic valve module, a first manual shutdown button, a B-path PLC, an even-number relay module, an even-number electromagnetic valve module and a second manual shutdown button, the A-path PLC and the odd-number relay module form a first control loop, the odd-number electromagnetic valve module forms a second control loop, the B-path PLC and the even-number relay module form a third control loop, the even-number electromagnetic valve module forms a fourth control loop, and the first manual stop button is connected with the first control loop or the second control loop in series. And the second manual stop button is connected in series with the third control loop or the fourth control loop. According to the utility model, the two stop buttons are directly connected in series with the electromagnetic valve or the relay for controlling the electromagnetic valve, so that the control on the power supply of the AST electromagnetic valve or the AST relay is realized, and the purpose of manual stop is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to steam turbine manual shutdown control technical field especially relates to a steam turbine manual emergency shutdown control loop. BACKGROUND

[0002] Steam turbine emergency trip system is an important protection control device of the unit. Its action accuracy is related to whether the whole unit can run safely and stably, and is a very important protection device of the machine side. The steam turbine emergency trip system is used to monitor important parameters of the steam turbine. When the parameters exceed the running limit value, the system closes all steam turbine steam inlet valves and stops the machine in emergency to ensure the safe operation of the steam turbine.

[0003] Two sets of PLCs are used in the system cabinet to run in parallel, namely A PLC and B PLC. When the A PLC trips, odd channels (i.e. channels 1 and 3) trip. When the B PLC trips, even channels (i.e. channels 2 and 4) trip. The steam turbine trips when the two PLCs output simultaneously.

[0004] The current manual trip protection circuit is connected in series by two manual trip buttons installed on the operation table in the control room, and then sent to two sets of PLCs running in parallel for logical judgment. The output signal drives the trip solenoid valve (the A PLC drives the 1, 3 AST solenoid valve, and the B PLC drives the 2, 4 AST solenoid valve, as shown in FIG. Figure 3 The manual shutdown signal enters the ETS, and the shutdown is not realized by hardwiring. The signal, like other protection signals, is sent to the PLC for logical judgment, and then output by the DO5 card of the PLC to drive the solenoid valve. Therefore, in the current manual trip protection circuit, once the PLC of the ETS system crashes or the internal output module fault contact of the DO card cannot be disconnected, the emergency stop button may fail, causing a serious accident. UTILITY MODEL CONTENTS

[0005] The utility model aims at the above-mentioned problems, and provides a steam turbine manual emergency shutdown control loop. Two shutdown buttons are connected in series with the solenoid valve or the relay controlling the solenoid valve, so as to control the power supply of the AST solenoid valve or the AST relay, thereby achieving the purpose of manual shutdown and avoiding the problem of emergency stop button failure caused by the PLC crash of the ETS system or the internal output module fault contact of the DO card that cannot be disconnected.

[0006] In order to achieve the above-mentioned utility model purposes, the utility model adopts the following technical solutions:

[0007] According to one aspect of the utility model, a kind of steam turbine manual emergency shutdown control loop is provided, including A PLC controller, odd relay module, odd electromagnetic valve module, first manual stop button, B PLC controller, even relay module, even electromagnetic valve module and second manual stop button;

[0008] One end of the A PLC controller is connected to a first DC positive voltage, and the other end is connected in series with the odd relay module, and the end of the odd relay module away from the A PLC controller is grounded, forming a first control loop.

[0009] One end of the odd electromagnetic valve module is connected to a second DC positive voltage, and the other end is connected to a second DC negative voltage, forming a second control loop.

[0010] One end of the B PLC controller is connected to a first DC positive voltage, and the other end is connected in series with the even relay module, and the end of the even relay module away from the B PLC controller is grounded, forming a third control loop.

[0011] One end of the even electromagnetic valve module is connected to a second DC positive voltage, and the other end is connected to a second DC negative voltage, forming a fourth control loop.

[0012] The first manual stop button is connected in series with the first control loop or the second control loop.

[0013] The second manual stop button is connected in series with the third control loop or the fourth control loop.

[0014] Preferably, the A PLC controller includes a first A PLC output and a second A PLC output, the first A PLC output is connected in series with the odd relay module, and the second A PLC output is connected in series with the odd relay module.

[0015] Preferably, the odd relay module includes a first relay and a third relay, the first A PLC output is connected in series with the first relay, and the second A PLC output is connected in series with the third relay.

[0016] Preferably, the odd electromagnetic valve module includes a first capacitor, a first electromagnetic valve, a third capacitor and a third electromagnetic valve, the first capacitor is connected in series with the first electromagnetic valve, and the third capacitor is connected in series with the third electromagnetic valve.

[0017] Preferably, the B PLC controller includes a first B PLC output and a second B PLC output, the first B PLC output is connected in series with the even relay module, and the second B PLC output is connected in series with the even relay module.

[0018] Preferably, the even-numbered relay module comprises a second relay and a fourth relay, the first B-channel PLC output end is connected in series with the second relay, and the second B-channel PLC output end is connected in series with the fourth relay.

[0019] Preferably, the even-numbered electromagnetic valve module comprises a second capacitor, a second electromagnetic valve, a fourth capacitor and a fourth electromagnetic valve, the second capacitor is connected in series with the second electromagnetic valve, and the fourth capacitor is connected in series with the fourth electromagnetic valve.

[0020] In summary, due to the adoption of the above technical solutions, the present application has the following beneficial effects:

[0021] The two stop buttons are directly connected in series with the electromagnetic valve or the relay for controlling the electromagnetic valve, so that the power supply of the AST electromagnetic valve or the AST relay is controlled, the purpose of manual stop is achieved, and the problem of emergency stop button failure caused by the failure of the ETS system PLC or the DO card internal output module fault contact to be unable to be disconnected is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a circuit schematic diagram of the embodiment 1 of the present application;

[0023] Figure 2 is a circuit schematic diagram of the embodiment 1 of the present application;

[0024] Figure 3 is a circuit schematic diagram of the prior art of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application more clear, the following preferred embodiments are described with reference to the drawings. However, it should be noted that many details in the specification are only to make the reader have a thorough understanding of one or more aspects of the present application, and the present application can be realized even without these specific details.

[0026] Embodiment 1

[0027] Please refer to Figure 1 The present application provides a kind of steam turbine manual emergency stop control loop, technical scheme is as follows:

[0028] A kind of steam turbine manual emergency shutdown control loop, including A route PLC controller, odd relay module, odd electromagnetic valve module, first manual shutdown button, B route PLC controller, even relay module, even electromagnetic valve module and second manual shutdown button.A route PLC controller includes first A route PLC output and second A route PLC output.Odd relay module includes first relay and third relay.First A route PLC output is connected in series with first relay, second A route PLC output is connected in series with third relay, the series connection of first A route PLC output and first relay and the series connection of second A route PLC output and third relay are connected in parallel, form first control circuit, one end of first control circuit is connected with first direct current positive voltage, the other end is grounded, form first control loop.Wherein, first direct current positive voltage is 24V.

[0029] Odd electromagnetic valve module includes first capacitor, first electromagnetic valve, third capacitor and third electromagnetic valve.First capacitor is connected in series with first electromagnetic valve, third capacitor is connected in series with the third electromagnetic valve.The series connection of first capacitor and first electromagnetic valve and the series connection of third capacitor and third electromagnetic valve are connected in parallel, form second control circuit, one end of second control circuit is connected with second direct current positive voltage, the other end is connected with second direct current negative voltage, form second control loop.Wherein, second direct current positive voltage is +110V, second direct current negative voltage is-110V.First manual shutdown button is connected in series with second control loop.Through first manual shutdown button directly acts second control loop, controls the conduction and the closing of first electromagnetic valve and third electromagnetic valve.

[0030] B route PLC controller includes first B route PLC output and second B route PLC output.Even relay module includes second relay and fourth relay.First B route PLC output is connected in series with second relay, second B route PLC output is connected in series with fourth relay, the series connection of first B route PLC output and second relay and the series connection of second B route PLC output and fourth relay are connected in parallel, form third control circuit, one end of third control circuit is connected with first direct current positive voltage, the other end is grounded, form third control loop.

[0031] Even electromagnetic valve module includes second capacitor, second electromagnetic valve, fourth capacitor and fourth electromagnetic valve.Second capacitor is connected in series with second electromagnetic valve, fourth capacitor is connected in series with fourth electromagnetic valve.The series connection of second capacitor and second electromagnetic valve and the series connection of fourth capacitor and fourth electromagnetic valve are connected in parallel, form fourth control circuit, one end of fourth control circuit is connected with second direct current positive voltage, the other end is connected with second direct current negative voltage, form fourth control loop.Second manual shutdown button is connected in series with fourth control loop.

[0032] The first manual stop button two normally closed contacts are connected in series with a DC power supply circuit of an AST1 electromagnetic valve (first electromagnetic valve) and an AST3 electromagnetic valve (third electromagnetic valve) in an ETS cabinet, and the second manual stop button two normally closed contacts are connected in series with a DC power supply circuit of an AST2 electromagnetic valve (second electromagnetic valve) and an AST4 electromagnetic valve (fourth electromagnetic valve) in the ETS cabinet. The two stop buttons are used to control the power supply of the AST electromagnetic valve, so as to achieve the purpose of manual stop.

[0033] Embodiment 2

[0034] The power supply of the AST electromagnetic valve is connected in series with the normally closed contacts of the manual stop button, but since the original manual stop control circuit (24 DCV power supply provided by ETS) needs to be reserved, 220 DCV and 24 DCV are in the same button. When the insulation of the multi-layer button is not good (short circuit is easy to occur due to humid local climate), or the wires are connected incorrectly after maintenance, 220 DCV power supply is easy to be connected into the 24 DCV power supply circuit, which will cause accidents such as PLC channel, card fault of ETS system, and power supply damage of ETS system, and will cause hidden troubles for safe and stable operation of the steam turbine. At the same time, after the 220 DCV DC power supply is introduced into the operator station panel cabinet, it will also cause inconvenience to the maintenance of the emergency button control circuit of the panel cabinet in the future. Therefore, in order to solve the above problems, the utility model provides a steam turbine manual emergency stop control circuit, and the technical scheme is as follows:

[0035] As shown in Figure 2 In this embodiment, the first manual stop button is connected in series with the first control circuit. The first manual stop button directly acts on the first control circuit to control the conduction and closing of the first relay and the third relay, so that without changing the first manual stop button, the problem of the power supply of the AST electromagnetic valve being connected in series with the normally closed contacts of the manual stop button is avoided.

[0036] The second manual stop button is connected in series with the third control circuit. The second manual stop button directly acts on the third control circuit to control the conduction and closing of the second relay and the fourth relay, so that without changing the first manual stop button, the problem of the power supply of the AST electromagnetic valve being connected in series with the normally closed contacts of the manual stop button is avoided.

[0037] The two normally closed contacts of the first manual stop button are connected in series with the control power supply of the AST1 relay (first relay) and the AST3 relay (third relay) in the ETS cabinet, and the two normally closed contacts of the second manual stop button are connected in series with the control power supply of the AST2 relay (second relay) and the AST4 relay (fourth relay) in the ETS cabinet. The control power supply of the AST1 relay, the AST2 relay, the AST3 relay and the AST4 relay is controlled through the two stop buttons, so that the four relay contacts in the power supply circuit (AST1, AST2, AST3 and AST4) are disconnected, the power supply of the electromagnetic valve is cut off, and manual stop is realized.

[0038] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A manual emergency shutdown control loop for a steam turbine, characterized in that, The A PLC controller, the odd relay module, the odd electromagnetic valve module, the first manual stop button, the B PLC controller, the even relay module, the even electromagnetic valve module and the second manual stop button are connected in series. One end of the A PLC controller is connected with a first direct current positive voltage, and the other end is connected with the odd relay module in series. One end of the odd electromagnetic valve module is connected with a second direct current positive voltage, and the other end is connected with a second direct current negative voltage. One end of the B PLC controller is connected with the first direct current positive voltage, and the other end is connected with the even relay module in series. One end of the even electromagnetic valve module is connected with the second direct current positive voltage, and the other end is connected with the second direct current negative voltage. The first manual stop button is connected in series with the first control circuit or the second control circuit. The second manual stop button is connected in series with the third control circuit or the fourth control circuit.

2. A manual emergency shutdown control circuit for a steam turbine according to claim 1, characterized in that: The A PLC controller comprises a first A PLC output end and a second A PLC output end.

3. A manual emergency shutdown control circuit for a steam turbine according to claim 2, characterized in that: The odd relay module comprises a first relay and a third relay.

4. A manual emergency shutdown control circuit for a steam turbine as recited in claim 1, wherein: The odd electromagnetic valve module comprises a first capacitor, a first electromagnetic valve, a third capacitor and a third electromagnetic valve.

5. A manual emergency shutdown control circuit for a steam turbine as recited in claim 1, wherein: The B PLC controller comprises a first B PLC output end and a second B PLC output end.

6. A manual emergency shutdown control circuit for a steam turbine according to claim 5, characterized in that: The even relay module comprises a second relay and a fourth relay.

7. A manual emergency shutdown control circuit for a steam turbine as defined in claim 1 wherein: The even electromagnetic valve module comprises a second capacitor, a second electromagnetic valve, a fourth capacitor and a fourth electromagnetic valve.

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