Automatic switching control system of steam turbine adjusting steam valve

Abstract

The invention discloses an automatic switching control system of a steam turbine adjusting steam valve, and belongs to the technical field of adjusting valve control. An automatic switching control system of a steam turbine adjusting steam valve comprises a control module and an adjusting steam valve hydraulic servo-motor, and is characterized in that the control module comprises two sets of parallel main oil ways provided with electromagnetic valves and servo valves, and the two sets of parallel main oil ways are used for controlling the working state of the adjusting steam valve hydraulic servo-motor; wherein the electromagnetic valve and the servo valve on one group of main oil way are in electromagnetic-hydraulic pilot control, and the safety oil way is connected with the adjusting steam valve hydraulic servo-motor in parallel and is matched with the electromagnetic-hydraulic pilot control; the auxiliary oil way is arranged in a standby mode, it can be guaranteed that the steam valve hydraulic servo-motor is controlled and adjusted to be in a non-stop working state, the safety oil way is arranged, on-site fault processing can be further achieved, feedback operation time is shortened, and working safety and stability of the oil way are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of regulating valve control, and in particular to an automatic switching control system for a steam turbine regulating steam valve. Background Art

[0002] Steam turbines are the most widely used prime movers in thermal power plants. The principle is to control the amount of steam intake by adjusting the opening of the regulating valves distributed on both sides of the steam turbine. The steam throttled by the regulating valves blows the blades on the turbine rotor to rotate the rotor, thereby driving the generator rotor to rotate and generate electricity. Among them, the greater the load carried by the generator, the more steam intake the steam turbine needs. The operating modes of the steam turbine regulating valve are divided into single valve mode and sequential valve mode. During the actual operation of the steam turbine, switch between the single valve mode and the sequential valve mode according to different working conditions.

[0003] Due to the wear of the regulating valve during the operation of the steam turbine, the disassembly, installation and grinding of the regulating valve during the maintenance process, the flow characteristics of the regulating valve change, and the overload of the system during operation, the oil circuit system fluctuates greatly. Therefore, an automatic switching control system for the regulating valve of the steam turbine is proposed. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of damage to the oil circuit system caused by turbine maintenance and overload in the prior art, and to propose an automatic switching control system for a turbine regulating steam valve.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: An automatic switching control system for a steam turbine regulating steam valve comprises a control module and a regulating steam valve oil motor, wherein the control module comprises two sets of parallel main oil circuits provided with solenoid valves and servo valves for controlling the working state of the regulating steam valve oil motor, wherein the solenoid valves and servo valves on one set of main oil circuits are electromagnetic-hydraulic pilot controlled, and further comprises a safety oil circuit in parallel with the regulating steam valve oil motor, wherein the safety oil circuit cooperates with the electromagnetic-hydraulic pilot control.

[0006] In order to ensure the rapid and stable operation of the safety oil circuit, preferably, the safety oil circuit includes a starting oil circuit connected to the electromagnetic-hydraulic pilot control, an overflow valve is connected to the starting oil circuit, and a parallel safety valve is arranged on the starting oil circuit, and the safety valve cooperates with the main oil circuit through a guide oil circuit.

[0007] Furthermore, the opening pressure of the safety valve is 0.2-0.5 times the working pressure of the main oil circuit.

[0008] Furthermore, the safety valve is a DN500 spring type.

[0009] In order to improve the ease of use of the oil circuit system, preferably, the main oil circuit includes a working oil circuit and an auxiliary oil circuit, and the two circuits serve as backup for each other.

[0010] Furthermore, the working oil circuit includes a first oil circuit and a second oil circuit, which are used to control the rise and fall of the regulating steam valve oil motor, and the two groups of guide oil circuits are respectively connected to the first oil circuit and the second oil circuit.

[0011] Furthermore, both the working oil circuit and the auxiliary oil circuit are connected with stop valves.

[0012] Preferably, the solenoid valve is a three-position four-way valve, and the servo valve is a two-position four-way valve.

[0013] Compared with the prior art, the present invention provides an automatic switching control system for a steam turbine regulating steam valve, which has the following beneficial effects: 1. The automatic switching control system of the steam turbine regulating steam valve, the overload pressure drives the electromagnetic-hydraulic pilot-controlled solenoid valve and servo valve through the starting oil circuit. In this working state, the solenoid valve and servo valve are both moved down. At this time, the auxiliary oil circuit can quickly unload and return the overload of the working oil circuit to ensure the safety and stability of the system operation; 2. The automatic switching control system of the steam turbine regulating steam valve is designed to have an opening pressure of the safety valve 8 of 0.2-0.5 times the working pressure of the working oil circuit. Here, the preferred starting pressure is 0.4 times, which can not only ensure the normal output pressure of the system, but also prevent the oil circuit system from collapsing, effectively reducing damage to the oil circuit system; 3. The automatic switching control system of the steam turbine regulating steam valve drives the safety valve 8 to start normally through the overload pressure of the working oil circuit, and the servo valve 5 and the solenoid valve 4 move downward to make the auxiliary oil circuit 3 conductive for instantaneous pressure relief. The remote control system receives the alarm and responds quickly to control the solenoid valve 4 on the auxiliary oil circuit 3 to continue to move upward, so that the auxiliary oil circuit 3 replaces the working oil circuit and quickly enters the operating state to ensure uninterrupted operation.

[0014] The parts not involved in the device are the same as the existing technology or can be implemented by the existing technology. The present invention can ensure that the control and regulation steam valve oil motor is in a non-stop working state through the backup setting of the auxiliary oil circuit, and the setting of the safety oil circuit can further realize the on-site processing of faults, reduce the feedback operation time, and ensure the working safety and stability of the oil circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The structure diagram of the automatic switching control system of the steam turbine regulating steam valve proposed by the present invention is as follows Figure 1 ; Figure 2 The structure diagram of the automatic switching control system of the steam turbine regulating steam valve proposed by the present invention is as follows Figure 2; Figure 3 The present invention provides a flow chart of an automatic switching control system for a steam turbine regulating steam valve.

[0016] In the figure: 1. First oil circuit; 2. Second oil circuit; 3. Auxiliary oil circuit; 4. Solenoid valve; 5. Servo valve; 6. Stop valve; 7. Safety oil circuit; 8. Safety valve; 9. Overflow valve; 10. Starting oil circuit; 11. Adjusting steam valve oil motor. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0019] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the 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.

[0020] Embodiment 1: Reference Figure 1-Figure 3 Due to the wear of the regulating valve during the operation of the steam turbine, the disassembly, installation and grinding of the regulating valve during the maintenance process, the flow characteristics of the regulating valve change, and the overload of the system during the operation, based on this, an automatic switching control system for the regulating steam valve of the steam turbine is designed, including a control module and a regulating steam valve oil motor 11, a manual stop valve 6 is arranged between the control module and the regulating steam valve oil motor 11, which is used for manual operation during maintenance or maintenance, the control module includes two sets of parallel working oil circuits and auxiliary oil circuits 3 provided with a three-position four-way solenoid valve 4 and a two-position four-way servo valve 5, the two circuits are mutually standby, and are used to control the working state of the regulating steam valve oil motor 11, the solenoid valve 4 and the servo valve 5 on the auxiliary oil circuit 3 are electromagnetic-hydraulic pilot control, and also include a safety oil circuit 7 in parallel with the regulating steam valve oil motor 11, the safety oil circuit 7 cooperates with the electromagnetic-hydraulic pilot control, and is used to start the auxiliary oil circuit 3 on site to reduce the feedback operation time.

[0021] The safety oil circuit 7 includes a starting oil circuit 10 connected to the electromagnetic-hydraulic pilot control, an overflow valve 9 is connected to the starting oil circuit 10, and a spring-type DN500 safety valve 8 is arranged in parallel on the starting oil circuit 10. The safety valve 8 cooperates with the main oil circuit through the guide oil circuit. The working oil circuit includes a first oil circuit 1 and a second oil circuit 2, which are used to control the rise and fall of the steam valve oil motor 11. The two groups of safety oil circuits 7 are respectively connected to the first oil circuit 1 and the second oil circuit 2.

[0022] During normal operation, the auxiliary oil circuit 3 and the safety oil circuit 7 are both in a normally closed state. At this time, the solenoid valve 4 on the working oil circuit is controlled to move up or down to switch the action, so that the first oil circuit 1 and the second oil circuit 2 are in a working state, and then the rise and fall of the regulating steam valve oil motor 11 are controlled. Through the backup setting of the auxiliary oil circuit 3, it can be ensured that the regulating steam valve oil motor 11 is in a non-stop working state, and the setting of the safety oil circuit 7 can further realize on-site fault processing, reduce feedback operation time, and ensure the working safety and stability of the oil circuit.

[0023] Embodiment 2: Reference Figure 1-Figure 3 , which is basically the same as the first embodiment. Furthermore, due to the wear of the regulating valve during the operation of the steam turbine, the disassembly, installation and grinding of the regulating valve during the maintenance process, the flow characteristics of the regulating valve change, and the overload of the system during the operation, the opening pressure of the safety valve 8 is specifically designed to be 0.2-0.5 times the working pressure of the working oil circuit. Here, the preferred starting pressure is 0.4 times, which can not only ensure the normal output pressure of the system, but also prevent the collapse of the oil circuit system, and effectively reduce the damage to the oil circuit system. That is, when the working oil circuit pressure is overloaded by 20%-50%, the safety valve 8 is opened. Here, since the guide oil circuit is respectively connected to the first oil circuit 1 and the second oil circuit 2, that is, when the regulating steam valve oil motor 11 rises or falls, the safety valve 8 can be started. Specifically, the overload pressure drives the electromagnetic-hydraulic pilot-controlled solenoid valve 4 and the servo valve 5 through the starting oil circuit 10. The working state is that the solenoid valve 4 and the servo valve 5 are both moved downward. At this time, the auxiliary oil circuit 3 can quickly unload and return the overload of the working oil circuit to ensure the safety and stability of the system.

[0024] Embodiment three: Reference Figure 1-Figure 3, which is basically the same as the first embodiment. Furthermore, the auxiliary oil circuit 3 as a backup line, during the operation of the working oil circuit, due to the wear of the regulating valve during the operation of the steam turbine, the disassembly, installation and grinding of the regulating valve during the maintenance process, the flow characteristics of the regulating valve change, and the overload of the system during the operation, the overload pressure of the working oil circuit normally drives the safety valve 8 to start. At this time, the servo valve 5 and the solenoid valve 4 move down, so that the auxiliary oil circuit 3 is connected, and the pressure is instantly relieved. The remote control system receives the alarm and responds quickly to control the solenoid valve 4 on the auxiliary oil circuit 3 to continue to move up, so that the auxiliary oil circuit 3 replaces the working oil circuit and quickly enters the operating state, continuously ensuring that the regulating steam valve oil motor 11 completes the subsequent operations and tends to be stable. The working oil circuit can be directly inspected and processed by on-site personnel to ensure the uninterrupted operation.

[0025] Embodiment 4: Reference Figure 1-Figure 3 , which is basically the same as the first embodiment. Furthermore, as a spare auxiliary oil circuit 3, when the working oil circuit is in regular inspection or maintenance period, the auxiliary oil circuit 3 can be directly remotely controlled to work, thereby meeting the needs of uninterrupted production.

[0026] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An automatic switching control system for a steam turbine regulating steam valve, comprising a control module and a regulating steam valve oil motor (11), characterized in that: The control module comprises two sets of parallel main oil circuits provided with electromagnetic valves (4) and servo valves (5), which are used to control the working state of the regulating steam valve oil motor (11), wherein the electromagnetic valves (4) and servo valves (5) on one set of the main oil circuits are electromagnetic-hydraulic pilot controlled, and further comprises a safety oil circuit (7) connected in parallel with the regulating steam valve oil motor (11), wherein the safety oil circuit (7) cooperates with the electromagnetic-hydraulic pilot control.

2. The automatic switching control system for a steam turbine regulating valve according to claim 1, characterized in that: The safety oil circuit (7) comprises a starting oil circuit (10) connected to an electromagnetic-hydraulic pilot control, a relief valve (9) being connected to the starting oil circuit (10), and a parallel safety valve (8) being arranged on the starting oil circuit (10), the safety valve (8) cooperating with the main oil circuit via a pilot oil circuit.

3. The automatic switching control system for a steam turbine regulating valve according to claim 2, characterized in that: The opening pressure of the safety valve (8) is 0.2-0.5 times the working pressure of the main oil circuit.

4. The automatic switching control system for a steam turbine regulating steam valve according to claim 2 or 3, characterized in that: The safety valve (8) is a DN500 spring type.

5. The automatic switching control system for a steam turbine regulating valve according to claim 2, characterized in that: The main oil circuit comprises a working oil circuit and an auxiliary oil circuit (3), the two circuits serving as backup for each other.

6. The automatic switching control system for a steam turbine regulating valve according to claim 5, characterized in that: The working oil circuit comprises a first oil circuit (1) and a second oil circuit (2), which are used to control the rise and fall of the regulating steam valve oil motor (11), and the two groups of guide oil circuits are respectively connected to the first oil circuit (1) and the second oil circuit (2).

7. The automatic switching control system for a steam turbine regulating valve according to claim 6, characterized in that: The working oil circuit and the auxiliary oil circuit (3) are both connected to a stop valve (6).

8. The automatic switching control system for a steam turbine regulating valve according to claim 1, characterized in that: The solenoid valve (4) is a three-position four-way valve, and the servo valve (5) is a two-position four-way valve.

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