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CN-224215147-U - Air source control loop for emergency pneumatic valve of thermal power plant

CN224215147UCN 224215147 UCN224215147 UCN 224215147UCN-224215147-U

Abstract

The application relates to the technical field of thermal power plants, and provides an air source control loop of an emergency pneumatic valve for a thermal power plant. The air-conditioning system comprises a compressed air pipeline, a main electromagnetic valve, a position-preserving electromagnetic valve, a main electromagnetic valve and a power-off state, wherein the main electromagnetic valve is a two-position three-way electromagnetic valve and is arranged on the compressed air pipeline, an air inlet is connected with the compressed air, an air outlet is connected with an air cylinder of an emergency pneumatic valve, an air outlet is connected with the position-preserving electromagnetic valve, the position-preserving electromagnetic valve is a two-position three-way electromagnetic valve, the air outlet is connected with the air outlet of the main electromagnetic valve in series, the main electromagnetic valve and the position-preserving electromagnetic valve are configured to keep the air outlet closed in an electrified state, and the air outlet is opened in a power-off state. Through the dual redundancy structure of the main electromagnetic valve and the position-keeping electromagnetic valve which are configured in series, when the main electromagnetic valve is abnormally powered off and exhausted, the position-keeping electromagnetic valve can prevent the exhaust, so that the risk of misoperation of the emergency pneumatic valve is avoided, and the equipment safety is ensured.

Inventors

  • MI DALI
  • LIU HANG
  • LIU SHUZHOU
  • CHEN RUI
  • YUAN WEI
  • YIN WEIBO
  • HU MINJIE
  • DING WEI

Assignees

  • 中国电力工程顾问集团中南电力设计院有限公司
  • 中煤华中能源有限公司

Dates

Publication Date
20260508
Application Date
20250507

Claims (7)

  1. 1. An air supply control circuit for an emergency pneumatic valve of a thermal power plant, comprising: a compressed air line (1) for delivering compressed air; the main electromagnetic valve (3) is a two-position three-way electromagnetic valve and is arranged on the compressed air pipeline (1), the air inlet is connected with compressed air, the air outlet is connected with an air cylinder of the emergency pneumatic valve (5), and the air outlet is connected with the position-keeping electromagnetic valve (6); The position-keeping electromagnetic valve (6) is a two-position three-way electromagnetic valve, and the exhaust port is connected in series with the exhaust port of the main electromagnetic valve (3); The main electromagnetic valve (3) and the position-keeping electromagnetic valve (6) are configured to keep the exhaust port closed in a charged state and to open in a power-off state.
  2. 2. An air supply control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, characterized in that the position maintaining solenoid valve (6) and the main solenoid valve (3) are connected to different power supplies, respectively.
  3. 3. The air source control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, wherein the control signal input ends of the position-keeping solenoid valve (6) and the main solenoid valve (3) are respectively connected with different digital output clamping pieces in a distributed control system.
  4. 4. An air supply control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, characterized in that the main solenoid valve (3) and the position-preserving solenoid valve (6) are two-position three-way solenoid valves of the same specification.
  5. 5. An air supply control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, characterized in that an air filtering pressure reducing valve (2) is further arranged on the compressed air pipeline (1), and the output end of the air filtering pressure reducing valve (2) is connected with the air inlet end of the main electromagnetic valve (3).
  6. 6. An air supply control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, characterized in that the compressed air line (1) is further provided with a pressure indicator.
  7. 7. The gas source control circuit for an emergency pneumatic valve of a thermal power plant according to claim 1, characterized in that the emergency pneumatic valve (5) is an emergency shut-off valve or an emergency open valve.

Description

Air source control loop for emergency pneumatic valve of thermal power plant Technical Field The application relates to the technical field of thermal power plants, in particular to an air source control loop of an emergency pneumatic valve for a thermal power plant. Background The emergency pneumatic valve is widely used in a thermal power plant, and is powered by compressed air (0.4-0.8 MPa) and is divided into an emergency shutoff valve and an emergency opening valve. The emergency shut-off valve (FC, which functions in the form of an air-open, i.e. pneumatic valve is open during venting and closed during venting) is controlled by a solenoid valve. Under normal conditions, the electromagnetic valve is electrified, compressed air enters the air cylinder, and the emergency shut-off valve is opened. When an emergency occurs, the control system can automatically send out an instruction to cut off the power supply of the electromagnetic valve, and after the electromagnetic valve is powered off, the air inlet source of the pneumatic valve is closed, and compressed air in the cylinder of the pneumatic valve is discharged. The pneumatic valve is closed due to the loss of air supply. The emergency opening valve (FO), which acts in the form of an air-tight valve, i.e. the pneumatic valve is closed when venting and open when losing air, is controlled by a solenoid valve. Under normal conditions, the electromagnetic valve is electrified, compressed air enters the air cylinder, and the emergency shut-off valve is closed. When an emergency occurs, the control system can automatically send out an instruction to cut off the power supply of the electromagnetic valve, and after the electromagnetic valve is powered off, the air inlet source of the pneumatic valve is closed, and compressed air in the air cylinder is discharged. The pneumatic valve is opened due to the loss of air supply. The emergency shut-off valve and the emergency opening valve are controlled by the electromagnetic valve, the electromagnetic valve is electrified during normal operation, and once a power supply loop of the electromagnetic valve or the electromagnetic valve fails, an air inlet source of the pneumatic valve can be closed when the electromagnetic valve is powered off, compressed air in the air cylinder is discharged, so that the emergency shut-off valve and the emergency opening valve are in misoperation, equipment is damaged, and accidents are caused. Disclosure of Invention Therefore, the embodiment of the application provides an air source control loop of an emergency pneumatic valve for a thermal power plant, so as to solve the problem of misoperation of an emergency shut-off valve and an emergency opening valve caused by the power supply loop of an electromagnetic valve or the failure of the electromagnetic valve. An air source control loop of an emergency pneumatic valve for a thermal power plant according to an embodiment of the present application includes: A compressed air pipe for conveying compressed air; The main electromagnetic valve is a two-position three-way electromagnetic valve and is arranged on the compressed air pipeline, the air inlet is connected with compressed air, the air outlet is connected with an air cylinder of the emergency pneumatic valve, and the air outlet is connected with the position-keeping electromagnetic valve; the position-keeping electromagnetic valve is a two-position three-way electromagnetic valve, and the exhaust port is connected with the exhaust port of the main electromagnetic valve in series; The main solenoid valve and the position-keeping solenoid valve are configured to keep the exhaust port closed in a charged state and to open in a power-off state. In one embodiment, the position maintaining solenoid valve and the main solenoid valve are connected to different power sources, respectively. In one embodiment, control signal input ends of the position-keeping electromagnetic valve and the main electromagnetic valve are respectively connected with different digital output clamping pieces in the distributed control system. In one embodiment, the main solenoid valve and the position-maintaining solenoid valve are two-position three-way solenoid valves of the same specification. In one embodiment, an air filtering pressure reducing valve is further arranged on the compressed air pipeline, and the output end of the air filtering pressure reducing valve is connected with the air inlet end of the main electromagnetic valve. In one embodiment, a pressure indicator is further arranged on the compressed air pipeline. In one embodiment, the emergency pneumatic valve is an emergency shut-off valve or an emergency open valve. The air source control loop for the emergency pneumatic valve of the thermal power plant comprises a compressed air pipeline, a main electromagnetic valve, a position-keeping electromagnetic valve, an air outlet and an air outlet, wherein the compressed air pipeline is used for con