Mechanical overspeed protection system for a pumped storage unit

Abstract

The application discloses a mechanical overspeed protection system of a pumped storage unit, which comprises a guide vane servomotor start-up cavity, a guide vane servomotor shutdown cavity, a mechanical overspeed accident electromagnetic valve, an accident control oil valve, an accident pressure oil source, a mechanical protection pressure source, an overspeed limiter electromagnetic valve and a pure mechanical overspeed protection hydraulic switching device; the pure mechanical overspeed protection hydraulic switching device is connected with the overspeed limiter electromagnetic valve through a first pipeline; the overspeed limiter electromagnetic valve is connected with the accident control oil valve through a second pipeline; the accident control oil valve is connected with the mechanical protection pressure source through a third pipeline; the accident control oil valve is connected with the accident pressure oil source through a fourth pipeline; the accident control oil valve is connected with the mechanical overspeed accident electromagnetic valve through a fifth pipeline; and the mechanical overspeed accident electromagnetic valve is connected with the guide vane servomotor start-up cavity and the guide vane servomotor shutdown cavity respectively. The pure mechanical overspeed protection hydraulic switching device can ensure effective control of the overspeed of the unit in the case of a speed measurement system failure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical control, in particular to a mechanical overspeed protection system of pumped storage unit. BACKGROUND

[0002] Figure 1 Figure 2 The working schematic diagram of the protection system in the prior art is divided into IEs. When the overspeed signal is given by the speed measurement system, the overspeed limiter electromagnetic valve acts. At this time, the state of the overspeed limiter electromagnetic valve changes from the state shown in Fig. 1 to the state shown in Fig. 2. The accident pressure oil source closing cavity is connected to the oil discharge, the accident pressure oil source drives the accident electromagnetic valve to act, and the state of the accident electromagnetic valve changes from the state shown in Fig. 3 to the state shown in Fig. 4. The guide vane servomotor starting cavity is connected to the oil discharge, and the guide vane servomotor shutdown cavity is connected to the accident pressure oil source. At this time, the guide vane is closed, and the unit speed is reduced. However, when the speed measurement system fails to detect the false speed, the protection system will not act, which affects the safe operation of the unit. Figure 1 Figure 2 Figure 1 Figure 2 SUMMARY

[0003] Therefore, the embodiments of the present application provide a mechanical overspeed protection system of pumped storage unit to solve the problem that the protection system will not act when the speed measurement system fails to detect the false speed, which affects the safe operation of the unit.

[0004] In a first aspect, the embodiments of the present application provide a mechanical overspeed protection system of pumped storage unit, comprising: a guide vane servomotor starting cavity, a guide vane servomotor shutdown cavity, a mechanical overspeed accident electromagnetic valve, an accident control oil valve, an accident pressure oil source, a mechanical protection pressure source, an overspeed limiter electromagnetic valve and a pure mechanical overspeed protection hydraulic switching device.

[0005] The pure mechanical overspeed protection hydraulic switching device is connected with the overspeed limiter electromagnetic valve through a first pipeline, the overspeed limiter electromagnetic valve is connected with the accident control oil valve through a second pipeline, the accident control oil valve is connected with the mechanical protection pressure source through a third pipeline, the accident control oil valve is connected with the accident pressure oil source through a fourth pipeline, the accident control oil valve is connected with the mechanical overspeed accident electromagnetic valve through a fifth pipeline, and the mechanical overspeed accident electromagnetic valve is connected with the guide vane servomotor starting cavity and the guide vane servomotor shutdown cavity respectively.

[0006] Further, the pure mechanical overspeed protection hydraulic switching device comprises: an overspeed limiter oil inlet valve, an overspeed protection total oil return valve, a pure mechanical overspeed protection first isolation valve, a pure mechanical overspeed protection second isolation valve, a pure mechanical overspeed protection oil inlet valve and a pure mechanical overspeed electromagnetic valve.

[0007] ​​​​​The pure mechanical overspeed protection system further comprises a pure mechanical overspeed protection first isolation valve, a pure mechanical overspeed protection second isolation valve, a pure mechanical overspeed protection oil inlet valve, an overspeed limiter oil inlet valve, an overspeed limiter electromagnetic valve, an overspeed protection total oil return valve, and an accident control oil valve.

[0008] Further, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the overspeed limiter electromagnetic valve does not output an overspeed signal to the accident control oil valve.

[0009] When the accident control oil valve does not receive the overspeed signal, the accident control oil valve closes a fourth pipeline connected to the accident pressure oil source, opens a fifth pipeline connected to the mechanical protection pressure source, and transmits the pressure source obtained from the mechanical protection pressure source to the mechanical overspeed accident electromagnetic valve through the third pipeline.

[0010] The mechanical overspeed accident electromagnetic valve provides the pressure source for the guide vane servomotor when the mechanical overspeed accident electromagnetic valve does not receive the overspeed signal.

[0011] Further, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the overspeed limiter electromagnetic valve does not output an overspeed signal to the accident control oil valve.

[0012] When the accident control oil valve does not receive the overspeed signal, the accident control oil valve closes a fourth pipeline connected to the accident pressure oil source, opens a fifth pipeline connected to the mechanical protection pressure source, and transmits the pressure source obtained from the mechanical protection pressure source to the mechanical overspeed accident electromagnetic valve through the third pipeline.

[0013] The mechanical overspeed accident electromagnetic valve is in a first state and provides the pressure source for the guide vane servomotor when the mechanical overspeed accident electromagnetic valve does not receive the overspeed signal.

[0014] Further, the overspeed limiter oil inlet valve, the pure mechanical overspeed protection first isolation valve, the pure mechanical overspeed protection second isolation valve, and the pure mechanical overspeed protection oil inlet valve are all in an open state when the mechanical overspeed protection system is running.

[0015] Further, the pure mechanical overspeed electromagnetic valve is in a diagonal passing state when the pure mechanical overspeed does not occur, wherein the diagonal passing state is used to control the accident control oil valve to close the fourth pipeline connected with the accident pressure oil source and open the fifth pipeline connected with the mechanical protection pressure source.

[0016] Further, when the mechanical overspeed protection system is in the mechanical overspeed state, the pure mechanical overspeed electromagnetic valve is changed from the cross passage to the straight connection passage, and the overspeed limiter electromagnetic valve does not output the overspeed signal to the accident control oil valve.

[0017] When the accident control oil valve does not receive the overspeed signal, the accident control oil valve opens the fourth pipeline connected with the accident pressure oil source and closes the fifth pipeline connected with the mechanical protection pressure source, and the accident control oil valve transmits the pressure oil accessed by the accident pressure oil source to the mechanical overspeed accident electromagnetic valve through the third pipeline.

[0018] The mechanical overspeed accident electromagnetic valve is changed from the first state to the second state to make the guide vane servomotor connect the oil return pipe and the guide vane servomotor shutdown cavity access the pressure oil.

[0019] Further, the pure mechanical overspeed electromagnetic valve is changed from the diagonal passing state to the straight passing state, wherein the straight passing state is used to control the accident control oil valve to open the fourth pipeline connected with the accident pressure oil source and close the fifth pipeline connected with the mechanical protection pressure source.

[0020] The system provided by the embodiment of the present application can make the mechanical overspeed protection system of the pumped storage unit more perfect, ensure that the overspeed of the unit can be effectively controlled in the case of failure of the speed measurement system, and ensure safe and stable operation of the unit. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0022] Figure 1 The system normal working schematic diagram in the overspeed protection system in the prior art of the embodiment of the present application;

[0023] Figure 2 The protection action schematic diagram in the overspeed protection system in the prior art of the embodiment of the present application;

[0024] Figure 3A schematic diagram of a mechanical overspeed protection system of a pumped storage unit according to an embodiment of the present application;

[0025] Figure 4 A schematic diagram of a mechanical overspeed protection system of a pumped storage unit according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0027] A mechanical overspeed protection system of a pumped storage unit is provided in the embodiments of the present application, Figure 1 A schematic diagram of a mechanical overspeed protection system of a pumped storage unit according to an embodiment of the present application is shown in FIG. 1, which comprises: Figure 1

[0028] A guide vane servomotor start-up cavity 10, a guide vane servomotor shut-down cavity 20, a mechanical overspeed accident electromagnetic valve 30, an accident control oil valve 40, an accident pressure oil source 50, a mechanical protection pressure source 60, an overspeed limiter electromagnetic valve 70 and a pure mechanical overspeed protection hydraulic switching device 80;

[0029] The pure mechanical overspeed protection hydraulic switching device 80 is connected with the overspeed limiter electromagnetic valve through a first pipeline, the overspeed limiter electromagnetic valve 70 is connected with the accident control oil valve 40 through a second pipeline, the accident control oil valve 40 is connected with the mechanical protection pressure source 60 through a third pipeline, the accident control oil valve 40 is connected with the accident pressure oil source 50 through a fourth pipeline, the accident control oil valve 40 is connected with the mechanical overspeed accident electromagnetic valve 30 through a fifth pipeline, and the mechanical overspeed accident electromagnetic valve 30 is connected with the guide vane servomotor start-up cavity 10 and the guide vane servomotor shut-down cavity 20 respectively.

[0030] In the embodiments of the present application, as shown in FIG. 2, the pure mechanical overspeed protection hydraulic switching device 80 comprises: Figure 3

[0031] ​​The pure mechanical overspeed protection first isolation valve 803, the pure mechanical overspeed protection second isolation valve 804, and the pure mechanical overspeed protection oil inlet valve 805 are respectively connected to the pure mechanical overspeed electromagnetic valve 806. The pure mechanical overspeed protection oil inlet valve 805 is connected to the accident control oil valve 40. The pure mechanical overspeed protection second isolation valve 804 is connected to the overspeed protection total oil return valve 802. The overspeed limiter oil inlet valve 801 is connected to the pipeline between the pure mechanical overspeed protection oil inlet valve and the accident control oil valve 40 and the pipeline between the pure mechanical overspeed protection first isolation valve 803 and the overspeed limiter electromagnetic valve 70.

[0032] In the embodiment of the present application, as shown in Figure 3 When the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve 802 is in a closed state, and the overspeed limiter electromagnetic valve 70 does not output an overspeed signal to the accident control oil valve 40.

[0033] When the accident control oil valve 40 does not receive the overspeed signal, the accident control oil valve 40 closes the fourth pipeline connected to the accident pressure oil source 50, opens the fifth pipeline connected to the mechanical protection pressure source 60, and transmits the pressure source obtained by the mechanical protection pressure source 60 to the mechanical overspeed accident electromagnetic valve 30 through the third pipeline.

[0034] The mechanical overspeed accident electromagnetic valve 30 provides a pressure source for the guide vane servomotor when it does not receive the overspeed signal.

[0035] In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve 802 is in a closed state, and the overspeed limiter electromagnetic valve 70 does not output an overspeed signal to the accident control oil valve 40.

[0036] When the accident control oil valve 40 does not receive the overspeed signal, the accident control oil valve 40 closes the fourth pipeline connected to the accident pressure oil source 50, opens the fifth pipeline connected to the mechanical protection pressure source 60, and transmits the pressure source obtained by the mechanical protection pressure source 60 to the mechanical overspeed accident electromagnetic valve 40 through the third pipeline. The overspeed signal is used to indicate whether the pure mechanical overspeed occurs at present.

[0037] The mechanical overspeed accident electromagnetic valve 30 is in a first state and provides a pressure source for the guide vane servomotor when it does not receive the overspeed signal.

[0038] In the embodiment of the present application, the overspeed limiter oil inlet valve 70, the pure mechanical overspeed protection first isolation valve 803, the pure mechanical overspeed protection second isolation valve 804, and the pure mechanical overspeed protection oil inlet valve 805 are all in an open state when the mechanical overspeed protection system operates.

[0039] In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the pure mechanical overspeed electromagnetic valve is in a position shown in FIG. 8, and the mechanical overspeed protection system is in normal operation. Figure 3 In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the pure mechanical overspeed electromagnetic valve is in a position shown in FIG. 8, and the mechanical overspeed protection system is in normal operation. Figure 3 In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the pure mechanical overspeed electromagnetic valve is in a position shown in FIG. 8, and the mechanical overspeed protection system is in normal operation. Figure 3 In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the pure mechanical overspeed electromagnetic valve is in a position shown in FIG. 8, and the mechanical overspeed protection system is in normal operation. Figure 3 In the embodiment of the present application, when the mechanical overspeed protection system is in a normal state, the overspeed protection total oil return valve is in a closed state, and the pure mechanical overspeed electromagnetic valve is in a position shown in FIG. 8, and the mechanical overspeed protection system is in normal operation.

[0040] In the embodiment of the present application, the pure mechanical overspeed electromagnetic valve 806 is in a diagonal pass state when no pure mechanical overspeed occurs, and the diagonal pass state is used to control the accident control oil valve 40 to close the fourth pipeline connected with the accident pressure oil source 50 and open the fifth pipeline connected with the mechanical protection pressure source 60.

[0041] In the embodiment of the present application, when the mechanical overspeed protection system is in a mechanical overspeed state, the pure mechanical overspeed electromagnetic valve 806 is changed from a cross pass to a straight pass, and the overspeed limiter electromagnetic valve 70 does not output an overspeed signal to the accident control oil valve;

[0042] When the accident control oil valve 40 does not receive the overspeed signal, the accident control oil valve 40 opens the fourth pipeline connected with the accident pressure oil source 50 and closes the fifth pipeline connected with the mechanical protection pressure source 60, and the accident control oil valve 40 transmits the pressure oil from the accident pressure oil source to the mechanical overspeed accident electromagnetic valve through the third pipeline;

[0043] The mechanical overspeed accident electromagnetic valve 30 is changed from the first state to the second state, so that the guide vane servomotor is connected to the oil return pipe, and the guide vane servomotor shutdown cavity is connected to the pressure oil.

[0044] In the embodiment of the present application, the pure mechanical overspeed electromagnetic valve 806 is changed from a diagonal pass state to a straight pass state, and the straight pass state is used to control the accident control oil valve 40 to open the fourth pipeline connected with the accident pressure oil source 50 and close the fifth pipeline connected with the mechanical protection pressure source 60.

[0045] In the embodiment of the present application, the speed measurement system gives an overspeed signal, the pure mechanical overspeed electromagnetic valve is actuated, the cross pass is changed to a straight pass, the overspeed limiter electromagnetic valve remains unchanged due to no overspeed signal, and the accident control oil valve is changed from a position shown in FIG. 9 to a position shown in FIG. 10 due to the right side being under pressure and the pressure being higher than that of the left side. Figure 3 Figure 4 The function of cutting off the accident pressure oil is cancelled, the accident pressure oil enters the servomotor control system, and the mechanical overspeed accident electromagnetic valve is changed from a position shown in FIG. 10 to a position shown in FIG. 11 due to the overspeed signal. Figure 3 ​The position changes as Figure 4 As shown, the guide vane servo motor's opening chamber is connected to the return oil pipe, and the guide vane servo motor's closing chamber is connected to the emergency pressure oil. At this time, the guide vanes close, and the unit speed decreases.

[0046] In the embodiments of this application, such as Figure 4 As shown, after the speed measurement system issues an overspeed signal, the overspeed limiter solenoid valve activates. At this time, the overspeed limiter solenoid valve is activated by... Figure 3 The state change is Figure 4 In this state, the emergency pressure oil actuates the emergency solenoid valve, which is then activated by... Figure 3 The state changes shown are Figure 4 As shown, the guide vane servo motor's opening chamber is connected to drain oil, and the guide vane servo motor's closing chamber is connected to emergency pressure oil. At this time, the guide vanes are closed, and the unit speed decreases.

[0047] If the speed measurement system malfunctions and cannot detect the true rotational speed, causing the speed to continuously increase, when it reaches the point of pure mechanical overspeed, the pure mechanical overspeed solenoid valve will activate. Figure 3 The state changes shown are Figure 4 As shown in the diagram, the emergency pressure oil actuates the emergency solenoid valve, connecting the guide vane servo's opening chamber to the drain oil and its closing chamber to the emergency pressure oil. At this point, the guide vanes close, and the unit speed decreases.

[0048] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0049] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A mechanical overspeed protection system for a pumped storage unit, characterized by, include: Guide vane servo start chamber, guide vane servo stop chamber, mechanical overspeed accident solenoid valve, accident control oil valve, accident pressure oil source, mechanical protection pressure source, overspeed limiter solenoid valve and pure mechanical overspeed protection hydraulic switching device. The pure mechanical overspeed protection hydraulic switching device is connected to the overspeed limiter solenoid valve through a first pipeline. The overspeed limiter solenoid valve is connected to the emergency control oil valve through a second pipeline. The emergency control oil valve is connected to the mechanical protection pressure source through a third pipeline. The emergency control oil valve is connected to the emergency pressure oil source through a fourth pipeline. The emergency control oil valve is connected to the mechanical overspeed emergency solenoid valve through a fifth pipeline. The mechanical overspeed emergency solenoid valve is connected to the guide vane servo motor's start-up chamber and the guide vane servo motor's stop-up chamber, respectively. The pure mechanical overspeed protection hydraulic switching device includes: an overspeed limiter inlet valve, an overspeed protection main return valve, a pure mechanical overspeed protection first isolation valve, a pure mechanical overspeed protection second isolation valve, a pure mechanical overspeed protection inlet valve, and a pure mechanical overspeed solenoid valve. The pure mechanical overspeed solenoid valve is connected to the pure mechanical overspeed protection first isolation valve, the pure mechanical overspeed protection second isolation valve, and the pure mechanical overspeed protection inlet valve. The pure mechanical overspeed protection inlet valve is connected to the accident control oil valve. The pure mechanical overspeed protection second isolation valve is connected to the overspeed protection main return oil valve. The overspeed limiter inlet valve is connected to the pipeline between the pure mechanical overspeed protection inlet valve and the accident control oil valve, and to the pipeline between the pure mechanical overspeed protection first isolation valve and the overspeed limiter solenoid valve. When no pure mechanical overspeed occurs, the pure mechanical overspeed solenoid valve is in a deflection state. The deflection state is used to control the emergency control oil valve to close the fourth pipeline connected to the emergency pressure oil source and open the third pipeline connected to the mechanical protection pressure source. When the mechanical overspeed protection system is in a mechanical overspeed state, the pure mechanical overspeed solenoid valve changes from a cross passage to a straight-through passage and from an oblique passage state to a straight-through state, and the overspeed limiter solenoid valve does not output an overspeed signal to the accident control oil valve. The direct connection state is used to control the emergency control oil valve to open the fourth pipeline connected to the emergency pressure oil source and close the third pipeline connected to the mechanical protection pressure source.

2. The system of claim 1, wherein, When the mechanical overspeed protection system is in normal condition, the overspeed protection main return valve is closed, and the overspeed limiter solenoid valve does not output an overspeed signal to the emergency control valve. If no overspeed signal is received, the emergency control oil valve closes the fourth pipeline connected to the emergency pressure oil source and opens the third pipeline connected to the mechanical protection pressure source. The emergency control oil valve transmits the pressure source obtained by the mechanical protection pressure source to the mechanical overspeed emergency solenoid valve through the fifth pipeline. The overspeed signal is used to indicate whether a pure mechanical overspeed has occurred. The mechanical overspeed accident electromagnetic valve is in the first state without receiving the overspeed signal, and provides the pressure source for the guide vane servomotor.

3. The system of claim 2, wherein, The overspeed limiter inlet valve, the pure mechanical overspeed protection first isolation valve, the pure mechanical overspeed protection second isolation valve and the pure mechanical overspeed protection inlet valve are all in the open state when the mechanical overspeed protection system is running.

4. The system of claim 2, wherein, Without receiving the overspeed signal, the accident control oil valve opens the fourth pipeline connected with the accident pressure oil source, closes the third pipeline connected with the mechanical protection pressure source, and transmits the pressure oil from the accident pressure oil source to the mechanical overspeed accident electromagnetic valve through the fifth pipeline. The mechanical overspeed accident electromagnetic valve changes from the first state to the second state, so that the guide vane servomotor is connected to the oil return pipe, and the guide vane servomotor shutdown cavity is connected to the pressure oil.

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