Air exhaust check valve control system of steam turbine

Abstract

The utility model provides a steam turbine air exhaust check valve control system which comprises a main pipeline, an air exhaust check valve is installed in a control section of the main pipeline, a pneumatic execution device is installed on the outer side of the main pipeline, and a closed control air inlet and a safety test air inlet are formed in the air inlet end of the pneumatic execution device. A main control valve, a filtering device and an air supply valve block are sequentially installed on the air supply pipeline, a main air supply port and a testing air supply port are formed in the air supply valve block, an air inlet connected with the air supply pipeline is formed in the air supply valve block, the main air supply port is communicated with the closed control air inlet through a main air inlet pipeline, and an automatic control valve is arranged on the air supply valve block. The test air supply port is communicated with the safety test air inlet through a test air inlet pipeline, and the test air inlet pipeline is provided with a manual control valve for testing. The automatic control valve is used for controlling the main air inlet pipe to be connected so as to control the air exhaust check valve to be closed. During overhaul and maintenance, the manual control valve for testing can be connected with the testing air inlet pipeline to detect the working state of the air exhaust check valve on line.

Description

Technical Field

[0001] The invention belongs to the field of steam turbine equipment, and in particular relates to a steam turbine exhaust check valve control system. Background Art

[0002] The steam turbine of a power plant uses steam sent from the boiler to maintain the turbine speed (not connected to the grid) or load (connected to the grid), condenses the exhaust steam after work into water, and then sends it back to the boiler after heating with extraction steam. During the operation of the steam turbine, the exhaust check valve is an important device to ensure the safe operation of the steam turbine. It can prevent water from entering the steam turbine from the heater and pipeline. When the main valve is closed, the generator trips, and the water level of the heater reaches a dangerous value, the exhaust check valve needs to be closed to ensure safety. Since the exhaust check valve is in a normally open state, in the prior art, after the steam turbine has been running for a long time, it cannot be determined whether the exhaust check valve is stuck and affects the normal closing performance. Therefore, the reliability of use cannot be guaranteed. If it cannot be closed under special circumstances, it is easy to cause serious accidents. Therefore, it is necessary to design an exhaust check valve control system that can be tested during daily inspection and maintenance to ensure that the exhaust check valve is in normal use. Summary of the invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes a steam turbine exhaust check valve control system.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] A steam turbine exhaust check valve control system comprises a main pipeline and a control section of the main pipeline, an exhaust check valve is installed in the control section, and a pneumatic actuator is installed outside the control section. The pneumatic actuator is supplied with compressed gas from an air supply pipeline to execute the action of closing the exhaust check valve. The air inlet end of the pneumatic actuator is provided with a closed control air inlet and a safety test air inlet. A master control valve, a filter device and an air supply valve block are installed in sequence on the air supply pipeline. The air supply valve block is provided with a main air supply port and Test air supply port: the air supply valve block is provided with an air inlet connected to the air supply pipeline, and the air inlet is connected with the main air supply port and the test air supply port through the process channel at the same time; the main air supply port and the closed control air inlet are connected through the main air inlet pipeline, and the air supply valve block is provided with an automatic control valve for controlling the on-off of the main air inlet pipeline; the test air supply port and the safety test air inlet are connected through the test air inlet pipeline, and a manual control valve for testing is provided on the test air inlet pipeline, and the diameter of the test air inlet pipeline is smaller than the diameter of the main air inlet pipeline.

[0006] Furthermore, the automatic control valve adopts an electromagnetic control valve, for example, the electromagnetic control valve adopts an electromagnetic valve with a model of EF8316G064MO 220 / 50.

[0007] Furthermore, the filtering device adopts a filter pressure reducing valve, for example, the filter pressure reducing valve adopts a filter pressure reducing valve of SMC AW40-F04-B.

[0008] Furthermore, the master control valve is a manual stop valve.

[0009] Furthermore, the pneumatic actuator includes a pneumatic cylinder, the rod end of which extends into the control section to drive the air extraction check valve to operate.

[0010] Furthermore, the inner diameter of the control segment is larger than the inner diameter of the main pipeline, forming a step at the junction of the two. The diameter of the exhaust check valve is larger than the inner diameter of the main pipeline. When the exhaust check valve is closed, it can directly fit onto the step surface to form a reliable seal.

[0011] Furthermore, pressure detection devices are installed on the air supply pipeline, the main air intake pipeline, and the test air intake pipeline, and each pressure detection device is connected to the sound and light alarm device.

[0012] Furthermore, the filter device and the air supply valve block are both installed on a fixed bracket.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] The invention has a simple structure and reasonable design. The air inlet end of the pneumatic actuator is provided with a closed control air inlet and a safety test air inlet. The compressed gas is supplied by the main air inlet pipeline and the test air inlet pipeline respectively. The main air inlet pipe is connected by the automatic control valve to control the closing of the air extraction check valve. When inspecting and maintaining, the test air inlet pipeline can be connected by the test manual control valve to control the opening of the air extraction check valve to be reduced, and then the working state of the air extraction check valve can be detected online, which does not affect the normal operation of the equipment. The control is simple and efficient, and the safety and reliability are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0016] Figure 1 A schematic diagram of the structure created by the present invention. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0021] A steam turbine exhaust check valve control system, such as Figure 1 As shown, it includes a main pipeline 1 and a control segment 2 of the main pipeline, an air extraction check valve is installed in the control segment, and a pneumatic actuator 3 is installed on the outside of the control segment. The pneumatic actuator is supplied with compressed gas by an air supply pipeline 4 to execute the action of closing the air extraction check valve. The air inlet end of the pneumatic actuator is provided with a closed control air inlet and a safety test air inlet. The air supply pipeline is sequentially installed with a master control valve 5, a filter device 6 and an air supply valve block 7, and the air supply valve block is provided with a main air supply port and a test air supply port.

[0022] The air supply valve block is provided with an air inlet connected to the air supply pipeline, and the air inlet is connected with the main air supply port and the test air supply port at the same time through the process channel; the main air supply port and the closed control air inlet are connected through the main air inlet pipeline 8, and the air supply valve block is provided with an automatic control valve 9 for controlling the on-off of the main air inlet pipeline, and the test air supply port and the safety test air inlet are connected through a test air inlet pipeline 10. A manual control valve 11 for testing (for controlling the on-off of the air source in the test air inlet pipe) is provided on the test air inlet pipeline, and the diameter of the test air inlet pipeline is smaller than the diameter of the main air inlet pipeline.

[0023] Usually, the automatic control valve adopts an electromagnetic control valve, such as an electromagnetic control valve of model EF8316G064MO 220 / 50. The filter device adopts a filter pressure reducing valve, such as a filter pressure reducing valve of the filter device SMC AW40-F04-B. In order to ensure the stability of the structure, the filter device and the air supply valve block can be installed on a fixed bracket. As an example, the master control valve adopts a manual shut-off valve, which can manually shut off the air source when necessary, and has high reliability.

[0024] The above-mentioned pneumatic actuator includes a pneumatic cylinder, whose extension rod end extends into the control section to drive the air extraction check valve to operate. For example, the automatic control valve receives an instruction to control the main air intake pipe to be connected, compress and supply it to the pneumatic cylinder, and its extension rod extends, thereby controlling the air extraction check valve to close. During inspection and maintenance, the test air intake pipeline is connected through the test manual control valve, and compression is supplied to the pneumatic cylinder, and its extension rod extends, controlling the air extraction check valve to reduce its opening. When the staff confirms that the air extraction check valve operates normally, the test manual control valve can be closed and the pneumatic actuator can be restored to its original position (i.e., the normal open state).

[0025] It should be noted that since the test air intake pipeline flow controlled by the test manual control valve is smaller than the main air intake pipeline, the exhaust check valve closes relatively slowly. During this process, the staff can manually control the exhaust check valve to reduce the opening without completely closing the exhaust check valve. This control system design can ensure online detection of the working status of the exhaust check valve without affecting the normal operation of the equipment.

[0026] The inner diameter of the control segment is larger than the inner diameter of the main pipeline, forming a step at the connection between the two. The diameter of the exhaust check valve is larger than the inner diameter of the main pipeline. When the exhaust check valve is closed, it can directly fit on the step surface to form a reliable seal.

[0027] In an optional embodiment, pressure detection devices are installed on the gas supply pipeline, the main air intake pipeline, and the test air intake pipeline, and each pressure detection device is connected to an acoustic and visual alarm device. When the gas pressure in any pipeline is abnormal (too high or too low), the acoustic and visual alarm device will sound an alarm to remind the staff to deal with it urgently to ensure the safe operation of the equipment.

[0028] The invention has a simple structure and reasonable design. The air inlet end of the pneumatic actuator is provided with a closed control air inlet and a safety test air inlet. The compressed gas is supplied by the main air inlet pipeline and the test air inlet pipeline respectively. The main air inlet pipe is connected by the automatic control valve to control the closing of the air extraction check valve. When inspecting and maintaining, the test air inlet pipeline can be connected by the test manual control valve to control the opening of the air extraction check valve to be reduced, and then the working state of the air extraction check valve can be detected online, which does not affect the normal operation of the equipment. The control is simple and efficient, and the safety and reliability are high.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A steam turbine exhaust check valve control system, characterized in that: It comprises a main pipeline and a control section of the main pipeline, an exhaust check valve is installed in the control section, a pneumatic actuator is installed on the outer side of the control section, the pneumatic actuator is supplied with compressed gas by the air supply pipeline to execute the action of closing the exhaust check valve, a closed control air inlet and a safety test air inlet are arranged at the air inlet end of the pneumatic actuator, a main control valve, a filter device and an air supply valve block are sequentially installed on the air supply pipeline, a main air supply port and a test air supply port are arranged on the air supply valve block, an air inlet connected to the air supply pipeline is arranged on the air supply valve block, the air inlet is connected with the main air supply port and the test air supply port at the same time through a process channel; the main air supply port and the closed control air inlet are connected through the main air inlet pipeline, an automatic control valve for controlling the on-off of the main air inlet pipeline is arranged on the air supply valve block, the test air supply port and the safety test air inlet are connected through the test air inlet pipeline, a manual control valve for testing is arranged on the test air inlet pipeline, and the diameter of the test air inlet pipeline is smaller than the diameter of the main air inlet pipeline.

2. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The automatic control valve adopts an electromagnetic control valve.

3. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The filtering device adopts a filtering pressure reducing valve.

4. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The master control valve is a manual stop valve.

5. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The pneumatic actuator comprises a pneumatic cylinder, the rod end of which extends into the control section to drive the air extraction check valve to move.

6. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The inner diameter of the control section is larger than the inner diameter of the main pipe.

7. A steam turbine exhaust check valve control system according to claim 1, characterized in that: Pressure detection devices are installed on the air supply pipeline, the main air intake pipeline, and the test air intake pipeline, and each pressure detection device is connected to an audible and visual alarm device.

8. A steam turbine exhaust check valve control system according to claim 1, characterized in that: The filter device and the air supply valve block are both installed on a fixed bracket.

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