Bypass pneumatic control circuit and method of controlling the same

Abstract

The present application relates to the technical fields of power generation equipment, in particular to a bypass pneumatic control loop and a control method thereof, comprising a valve cylinder and a pneumatic valve positioner installed on a gas source pipe, a gas distribution pipe is also installed on the gas source pipe, a gas outlet end of the gas distribution pipe is connected to an A1 gas inlet of a first electromagnetic valve, an A3 gas inlet of the first electromagnetic valve is connected to the pneumatic valve positioner through a first connecting pipe, and an A2 gas outlet of the first electromagnetic valve is connected to a cylinder opening interface of the valve cylinder; compared with the prior art, the present application can realize the opening of the bypass door in an emergency when the control system fails or the power supply is lost, ensure the smoothness of the loop in an emergency, give the main road fault processing time, increase the system fault tolerance, and provide the stability of the unit operation.

Description

Technical Field

[0001] This invention relates to the field of power generation equipment technology, specifically to a bypass pneumatic control loop and its control method. Background Technology

[0002] Power plant thermal systems are equipped with pneumatic bypass valves as backup channels for the main circuit. When a main circuit equipment malfunctions and causes a blockage, the bypass valve is opened to ensure the circuit remains unobstructed and the unit operates normally.

[0003] However, pneumatic bypass doors require control commands and power supply from the control system. If either the control system malfunctions or the power supply fails, the door cannot be opened. A failed bypass door can have serious consequences. Therefore, this invention proposes a pneumatic bypass control loop and its control method. Summary of the Invention

[0004] The purpose of this invention is to provide a solution that automatically opens the pneumatic bypass door when either the control system fails or the power supply is lost, thus maintaining the circuit and ensuring the normal operation of the unit.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a bypass pneumatic control circuit, comprising a valve cylinder and a pneumatic valve positioner installed on an air source pipe, wherein an air distribution pipe is also installed on the air source pipe, the outlet end of the air distribution pipe is connected to the A1 inlet of a first solenoid valve, the A3 inlet of the first solenoid valve is connected to the pneumatic valve positioner through a first connecting pipe, and the A2 outlet of the first solenoid valve is connected to the cylinder opening port of the valve cylinder, the outlet end of the pneumatic valve positioner is also connected to the B1 inlet of a second solenoid valve through a second connecting pipe, and the B4 outlet of the second solenoid valve is connected to the cylinder closing port of the valve cylinder.

[0006] As a preferred embodiment of the present invention, both the second solenoid valve and the first solenoid valve are two-position five-way solenoid valves.

[0007] As a preferred embodiment of the present invention, the valve cylinder is a rotary cylinder.

[0008] As a preferred embodiment of the present invention, a filter pressure reducing valve is also installed on the gas source pipe.

[0009] A control method for a bypass pneumatic control circuit, wherein the power supply of the first solenoid valve and the second solenoid valve is taken from the same power source of the control circuit, and the power supply is switched on and off by the switching quantity of the control system.

[0010] As a preferred technical solution of the present invention, the method of controlling the power supply to be switched on and off by the control system is as follows:

[0011] a) The on / off control channels of the first solenoid valve and the second solenoid valve are set under the same controller as the control signal of the pneumatic valve positioner.

[0012] b) The power control switch points of the first solenoid valve and the second solenoid valve are set to the normally closed state.

[0013] c) When the controller fails, the signal flips.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The present invention provides a bypass pneumatic control circuit and its control method, which can ensure that when the control system fails or the power is lost, the bypass door can be opened in an emergency by utilizing the air source in the air source pipe to ensure the air path from the air distribution pipe and the first solenoid valve to the valve cylinder is unobstructed, thus ensuring the smooth flow of the circuit during emergency, giving the main circuit time to handle faults, increasing the system fault tolerance, and providing unit operation stability.

[0016] Other features and advantages of the present invention will be described in detail in the following specific embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the switch control channel setup proposed in an embodiment of the present invention;

[0019] In the diagram: 1. Air source pipe; 11. Air distribution pipe; 12. Filter pressure reducing valve; 2. Pneumatic valve positioner; 3. First solenoid valve; 31. A1 air inlet; 32. A2 air outlet; 33. A3 air inlet; 4. Second solenoid valve; 41. B1 air inlet; 44. B4 air outlet; 5. Valve cylinder; 51. Cylinder opening port; 52. Cylinder closing port. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Please see Figure 1-2 In this embodiment, a bypass pneumatic control circuit and its control method are provided, including a valve cylinder 5 and a pneumatic valve positioner 2 installed at the outlet end of the air source pipe 1. The pneumatic valve positioner 2 adopts the Yongtai YT-1000R pneumatic valve regulating positioner. An air distribution pipe 11 is installed on the air source pipe 1. The outlet end of the air distribution pipe 11 is connected to the A1 air inlet 31 of the first solenoid valve 3. The A3 air inlet 33 of the first solenoid valve 3 is connected to the pneumatic valve positioner 2 through a first connecting pipe. The A2 air outlet 32 ​​of the first solenoid valve 3 is connected to the cylinder opening interface 51 of the valve cylinder 5. The outlet end of the pneumatic valve positioner 2 is also connected to the B1 air inlet 41 of the second solenoid valve 4 through a second connecting pipe. The B4 air outlet 44 of the second solenoid valve 4 is connected to the cylinder closing interface 52 of the valve cylinder 5.

[0024] Both the second solenoid valve 4 and the first solenoid valve 3 are two-position five-way solenoid valves.

[0025] Specifically, both the first solenoid valve 3 and the second solenoid valve 4 can be solenoid valves of model ASCO531.

[0026] Valve cylinder 51 is a rotary cylinder.

[0027] A filter pressure reducing valve 12 is also installed on the gas source pipe 1. Specifically, the filter pressure reducing valve 12 can be a brand of [brand name missing]. AIRTAC Airtac's AL2000 filter pressure reducing valve can be used to remove impurities from the air source.

[0028] A control method for a bypass pneumatic control circuit, wherein the power supply of the first solenoid valve 3 and the second solenoid valve 4 is taken from the same power source as the control circuit, and the power supply is switched on and off by the switching quantity of the control system.

[0029] Specifically, the method by which the power supply is switched on and off via the control system's switching inputs is as follows:

[0030] a) The on / off control channels of the first solenoid valve 3 and the second solenoid valve 4 are set under the same controller as the control signal of the pneumatic valve positioner 2.

[0031] b) The power control switch points of the first solenoid valve 3 and the second solenoid valve 4 are set to normally closed.

[0032] c) When the controller fails, the signal flips.

[0033] It should be noted that:

[0034] When the control system is normal and the power supply is normal, the first solenoid valve 3 and the second solenoid valve 4 are normally energized. The A3 inlet 33 of the first solenoid valve 3 is connected to the A2 outlet 32, and the A1 inlet 31 is disconnected from the A2 outlet 32.

[0035] The B1 inlet 41 of the second solenoid valve 4 is connected to the B4 outlet 44.

[0036] This allows the valve positioner 2 to form an air passage through the cylinder opening interface 51 of the valve cylinder 5, ensuring smooth airflow. The valve positioner 2 can then be used to control the opening and closing of the valve cylinder 5 normally.

[0037] When the control system malfunctions, the controller issues a Timeout, causing the power control switches of the first solenoid valve 3 and the second solenoid valve 4 to disconnect, resulting in power disconnection (i.e., power loss). At this time, the first solenoid valve 3 and the second solenoid valve 4 lose power.

[0038] After the first solenoid valve 3 and the second solenoid valve 4 are de-energized, the A3 inlet 33 and the A2 outlet 32 ​​of the first solenoid valve 3 are disconnected, and the A1 inlet 31 and the A2 outlet 32 ​​are connected.

[0039] The B1 inlet 41 of the second solenoid valve 4 is disconnected from the B4 outlet 44.

[0040] At this time, the air circuit controlling the valve positioner 2 to the valve cylinder 5 is cut off, and the air source enters the valve cylinder 5 through the A1 air inlet 31 of the first solenoid valve 3, so that the valve cylinder 5 can be opened quickly, thereby ensuring that the water in the valve body controlled by the valve cylinder 5 can remain unobstructed, which can guarantee the water supply for the power plant equipment.

[0041] This invention enables the bypass door to open in emergency situations when the control system fails or the power is lost, by utilizing the air source in the air source pipe 1 to ensure the air path is unobstructed through the air distribution pipe 11 and the first solenoid valve 3 to the valve cylinder 5. This ensures the smooth flow of the circuit during emergency situations, provides time for handling main circuit faults, increases the system's fault tolerance, and provides stability for unit operation.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A bypass pneumatic control circuit, comprising a valve cylinder (5) and a pneumatic valve positioner (2) mounted on an air source pipe (1), characterized in that, The gas source pipe (1) is also equipped with a gas distribution pipe (11). The outlet end of the gas distribution pipe (11) is connected to the A1 inlet (31) of the first solenoid valve (3). The A3 inlet (33) of the first solenoid valve (3) is connected to the pneumatic valve positioner (2) through the first connecting pipe. The A2 outlet (32) of the first solenoid valve (3) is connected to the cylinder opening interface (51) of the valve cylinder (5). The outlet end of the pneumatic valve positioner (2) is also connected to the B1 inlet (41) of the second solenoid valve (4) through the second connecting pipe. The B4 outlet (44) of the second solenoid valve (4) is connected to the cylinder closing interface (52) of the valve cylinder (5). The second solenoid valve (4) and the first solenoid valve (3) are both two-position five-way solenoid valves. The valve cylinder (5) is a rotary cylinder. The gas source pipe (1) is also equipped with a filter pressure reducing valve (12).

2. The control method for a bypass pneumatic control loop according to claim 1, characterized in that, The power supply of the first solenoid valve (3) and the second solenoid valve (4) is taken from the same power source of the control circuit, and the power supply is controlled by the switching quantity of the control system.

3. The control method for a bypass pneumatic control loop according to claim 2, characterized in that, The method by which the power supply is switched on and off via a control system is as follows: a) The on / off control channels of the first solenoid valve (3) and the second solenoid valve (4) are set under the same controller as the control signal of the pneumatic valve positioner (2); b) The power control switch points of the first solenoid valve (3) and the second solenoid valve (4) are set to normally closed state. c) When the controller fails, the signal flips.

Images