Steam extraction check valve control system

Abstract

The utility model discloses a steam extraction check valve control system which comprises a pneumatic actuator and a steam extraction check valve electromagnetic valve communicated with the input end of the pneumatic actuator, and further comprises a first gas circuit and a second gas circuit which are communicated with the input end of the steam extraction check valve electromagnetic valve through a multi-way connector. Air is supplied to the steam extraction check valve electromagnetic valve through the first air path and the second air path which are independent of each other, air sources of the two air paths are relatively independent, normal air supply can still be achieved when any air source or air path goes wrong, it is ensured that a pneumatic actuator can work normally when a steam turbine stops or loads are suddenly reduced, and the safety of the steam extraction check valve electromagnetic valve is guaranteed. The first gas path and the second gas path are provided with check valves, one-way ventilation is achieved, and airflow backflow is avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of steam turbines, and in particular to the technical field of extraction steam non-return valve control systems. Background Technology

[0002] The non-return valve (NRV) for extraction steam in thermal power plants is a critical safety device used to prevent steam from flowing back into the turbine when it shuts down or the load suddenly decreases. When the turbine load changes or it shuts down, the NRV closes quickly to prevent steam backflow and protect the turbine and related equipment. Early extraction NRVs were mostly mechanical, relying on gravity or spring force to close. This design was simple, but its response speed was slow, and it was prone to jamming or incomplete sealing. With technological advancements, modern extraction NRVs utilize advanced technologies such as solenoid valve control and pneumatic actuators, significantly improving response speed and reliability.

[0003] For example, Chinese utility model patent CN221170214U proposes a pneumatic control system for a turbine extraction non-return valve, including a main control circuit for the turbine extraction non-return valve and a power source. A quick-exhaust valve for the turbine extraction non-return valve is installed on the main control circuit. This quick-exhaust valve is connected via a pipe to a needle valve C, a solenoid valve B, a filter, and a needle valve A. The needle valve C, solenoid valve B, filter, and needle valve A form the air supply branch pipe for the turbine extraction non-return valve. A bypass channel is connected to both ends of needle valve A and needle valve C, and a needle valve D is installed on the bypass channel. This utility model's pneumatic control system for a turbine extraction non-return valve is safe and reliable, has a simple structure, is easy to establish a power source, and is pollution-free. During maintenance, the bypass valve can be opened without affecting the normal operation of the non-return valve. For non-return valves located at high positions, this system can also be moved to the ground for convenient maintenance. For example, the public account is

[0004] Chinese utility model patent CN210118488U proposes a solenoid valve for testing the operation of a non-return valve, while Chinese utility model patent CN213117696U proposes a manual test valve for a non-return valve.

[0005] Solenoid valve-controlled check valves can close within milliseconds, effectively preventing steam backflow. Extraction check valves need to close in an extremely short time to prevent steam backflow from damaging the turbine. However, the problem with existing technology is that pneumatic actuators mostly rely on a single air source. When the air source malfunctions, even if the solenoid valve can open effectively, the pneumatic actuator will not function properly. Summary of the Invention

[0006] The purpose of this invention is to solve the problems in the existing technology and propose a steam extraction non-return valve control system that uses dual gas sources for a safer and more reliable operation.

[0007] To achieve the above objectives, this utility model proposes a steam extraction non-return valve control system, including a pneumatic actuator and a steam extraction non-return valve solenoid valve connected to the input end of the pneumatic actuator. It also includes a first air path and a second air path connected to the input end of the steam extraction non-return valve solenoid valve via a multi-port connector. The first air path includes a first air source and a first check valve connected to the first air source. The output end of the first check valve is connected to the input end of the steam extraction non-return valve solenoid valve via the multi-port connector. The second air path includes a second air source and a second check valve connected to the second air source. The output end of the second check valve is connected to the input end of the steam extraction non-return valve solenoid valve via the multi-port connector.

[0008] The first gas source and the second gas source are gas sources from different sources and are independent of each other.

[0009] Preferably, either the first gas source or the second gas source is a gas storage cylinder.

[0010] Preferably, either the first air source or the second air source is an air compressor system.

[0011] Preferably, both the first air path and the second air path are equipped with air filters.

[0012] Preferably, both the first and second air paths are equipped with manual bypasses. The manual bypass includes a first manual valve, the input end of which is connected to the air source of the air path, and the output end of which is connected to the multi-port connector. The input ends of the first and second air paths are equipped with second manual valves, and the output ends are equipped with third manual valves.

[0013] Preferably, the extraction non-return valve solenoid valve includes a solenoid valve body and a manual test push rod that is axially movable on the solenoid valve body. The manual test push rod is used to manually control the solenoid valve body. A protrusion is provided next to the manual test push rod, and a control arm is hinged to the protrusion. The middle part of the control arm is hinged to the top of the manual test push rod.

[0014] Preferably, a reset spring is provided between the control arm and the solenoid valve body for driving the control arm to reset and lift.

[0015] The beneficial effects of this utility model's extraction steam non-return valve control system are as follows: This utility model supplies air to the extraction steam non-return valve solenoid valve through two separate first air lines and second air lines, and the air sources of the two air lines are relatively independent. Even if any air source or air line has a problem, it can still supply air normally, ensuring that the pneumatic actuator can work normally when the steam turbine stops or the load suddenly decreases. Both the first air line and the second air line are equipped with check valves, which allow one-way airflow and prevent backflow of air.

[0016] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an embodiment of the non-return valve control system of this utility model.

[0018] Figure 2 This is a schematic diagram of the second embodiment of the extraction steam non-return valve control system of this utility model.

[0019] Figure 3 This is a schematic diagram of the main structure of the extraction steam non-return valve solenoid valve in the extraction steam non-return valve control system of this utility model.

[0020] Figure 4 yes Figure 3 A partially enlarged structural diagram.

[0021] In the diagram: 1-Pneumatic actuator, 2-Extraction check valve solenoid valve, 3-First air source, 4-Multi-port connector, 5-First check valve, 6-Second air source, 8-Second check valve, 9-Air filter, 10-First manual valve, 11-Second manual valve, 12-Third manual valve, 101-Solenoid valve body, 102-Manual test push rod, 103-Protrusion, 104-Control arm. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit its scope. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0023] In the description of this utility model, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0024] In the description of this utility model, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0025] In the description of this utility model, 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 utility model based on the specific circumstances. Example 1

[0026] See Figure 1This utility model discloses a steam extraction non-return valve control system, including a pneumatic actuator 1, a steam extraction non-return valve solenoid valve 2 connected to the input end of the pneumatic actuator 1, a first air path, and a second air path. The first air path and the second air path are respectively connected to the input end of the steam extraction non-return valve solenoid valve 2 through a multi-port connector 4. In this embodiment, the pneumatic actuator 1 is a cylinder. The first air path includes a first air source 3 and a first check valve 5 connected to the first air source. The output end of the first check valve 5 is connected to the input end of the steam extraction non-return valve solenoid valve 2 through the multi-port connector 4. The second air path includes a second air source 6 and a second check valve 8 connected to the second air source 6. The output end of the second check valve 8 is connected to the input end of the steam extraction non-return valve solenoid valve 2 through the multi-port connector 4. The first air source 3 and the second air source 6 are air sources from different sources and are independent of each other. In this embodiment, the extraction steam non-return valve solenoid valve 2 is supplied with air through two independent first air passages and second air passages. The air sources of the two air passages are relatively independent. If any air source or air passage has a problem, the air supply can still be normal, ensuring that the pneumatic actuator 1 can work normally when the steam turbine stops or the load suddenly decreases. Both the first air passage and the second air passage are equipped with check valves, which allow one-way airflow and prevent backflow of air.

[0027] Specifically, in this embodiment, the first gas source 3 is a gas storage cylinder, and the second gas source 6 is an air compressor system. The two systems are relatively independent and do not interfere with each other, ensuring that the gas sources can be started normally in the event of an emergency.

[0028] See Figure 1 Air filters 9 are installed in both the first and second air passages to filter impurities in the air source and prevent damage to other components. Example 2

[0029] See Figure 2 Based on Embodiment 1, both the first and second gas lines are equipped with manual bypasses. Each manual bypass includes a first manual valve 10, whose input end is connected to the gas source of the gas line and whose output end is connected to the multi-port connector 4. The first and second gas lines are equipped with second manual valves 11 at their input ends and third manual valves 12 at their output ends. Under normal conditions, the second and third manual valves 11 and 12 of each manual bypass remain open, while the first manual valve 10 remains closed. When maintenance is required for any gas line, the first manual valve 10 of that gas line is opened, and the second and third manual valves 11 and 12 are closed to perform maintenance on that gas line. Example 3

[0030] See Figure 3 , Figure 4The extraction non-return valve solenoid valve 2 includes a solenoid valve body 101 and a manual test push rod 102 that is axially movable on the solenoid valve body 101. The manual test push rod 102 is used to manually control the solenoid valve body 101. A protrusion 103 is provided next to the manual test push rod 102. A control arm 104 is hinged to the protrusion 103. The middle part of the control arm 104 is hinged to the top of the manual test push rod 102. In this embodiment, the manual test push rod 102 is improved by setting a horizontally arranged control arm 104 on it. The control arm 104 drives the manual test push rod 102. Since the manual test push rod 102 is generally only used once a month or longer, and the working environment of the extraction steam non-return valve solenoid valve 2 is relatively harsh, the manual test push rod 102 is at risk of failure. In many cases, the manual test push rod 102 cannot be properly released after being pressed, which leads to the inability of the extraction steam non-return valve solenoid valve 2 to be used normally. When the internal spring of the manual test push rod 102 fails, the manual test push rod 102 can be pried up by the end of the control arm 104 to avoid the phenomenon that the manual test push rod 102 cannot be released.

[0031] Specifically, a reset spring (not shown in the figure) is provided between the control arm 104 and the solenoid valve body 101 to drive the control arm 104 to reset and lift. The reset spring can assist in resetting.

[0032] The working process of this utility model:

[0033] In the operation of this utility model's extraction steam non-return valve control system, both the first and second air paths supply air to the extraction steam non-return valve solenoid valve 2. When the extraction steam non-return valve solenoid valve 2 is triggered, the air sources of both the first and second air paths can supply air to the extraction steam non-return valve solenoid valve 2. The extraction steam non-return valve solenoid valve 2 supplies air to the pneumatic actuator 1, thereby driving the pneumatic actuator 1 to perform actions. Even if any air source or air path has a problem, it can still supply air normally. Both the first and second air paths are equipped with check valves, allowing one-way airflow and preventing backflow of air.

[0034] All standard parts used in this application can be purchased from the market. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the existing technology. The internal components of the electric slide rail, cylinder, welding machine, electric telescopic rod and controller all adopt conventional models in the existing technology, and their internal structure belongs to the existing technology structure. Workers can complete the normal operation of them according to the existing technical manual. In addition, the circuit connection adopts the conventional connection method in the existing technology, and will not be described in detail here.

[0035] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this utility model. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this utility model, or equivalent structural or procedural transformations made using the content of this utility model's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this utility model patent.

Claims

1. A control system for a steam extraction check valve, comprising a pneumatic actuator (1) and a steam extraction check valve solenoid (2) in communication with an input of the pneumatic actuator (1), characterized in that: Further comprising a first gas path and a second gas path communicated with the input end of the steam extraction check valve electromagnetic valve (2) through the multi-way joint (4), the first gas path comprising a first gas source (3), a first check valve (5) communicated with the first gas source (3), the output end of the first check valve (5) communicated with the input end of the steam extraction check valve electromagnetic valve (2) through the multi-way joint (4), the second gas path comprising a second gas source (6), a second check valve (8) communicated with the second gas source (6), the output end of the second check valve (8) communicated with the input end of the steam extraction check valve electromagnetic valve (2) through the multi-way joint (4); The first gas source (3) and the second gas source (6) are different sources and independent gas sources.

2. The extraction check gate control system of claim 1, wherein: Any one of the first gas source (3) and the second gas source (6) is a gas cylinder.

3. The control system for a steam extraction check valve as set forth in claim 1, wherein: Any one of the first gas source (3) and the second gas source (6) is an air pressure system.

4. The control system for a steam extraction check valve as set forth in claim 1, wherein: Air filters (9) are arranged in the first gas path and the second gas path.

5. The control system for a steam extraction check valve as set forth in claim 1, wherein: Manual bypasses are arranged on the first gas path and the second gas path, the manual bypass comprising a first manual valve (10), the input end of the first manual valve (10) communicated with the gas source of the gas path, the output end of the first manual valve (10) communicated with the multi-way joint (4), the input end of the first gas path and the second gas path provided with a second manual valve (11), the output end of the first gas path and the second gas path provided with a third manual valve (12).

6. The control system for a steam extraction check valve as set forth in claim 1, wherein: The steam extraction check valve electromagnetic valve (2) comprises an electromagnetic valve body (101) and a manually test push rod (102) axially movable arranged on the electromagnetic valve body (101), the manually test push rod (102) used for manually controlling the electromagnetic valve body (101), a lug (103) arranged beside the manually test push rod (102), the lug (103) hinged connected with a control arm (104), the middle part of the control arm (104) hinged connected with the top part of the manually test push rod (102).

7. The extraction check gate control system of claim 6, wherein: A reset spring is arranged between the control arm (104) and the electromagnetic valve body (101) for driving the control arm (104) to reset and lift up.

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