Hydraulic system structure capable of detecting internal leakage of isolating valve and internal leakage detection method

Abstract

The invention provides a hydraulic system structure capable of detecting internal leakage of an isolating valve and an internal leakage detection method, relates to the technical field of mechanical design of hydraulic systems, and solves the limitation problem that an existing detection mode is time-consuming and labor-consuming. The hydraulic system structure is sequentially connected with an isolating valve, a main distributing system oil source pipeline and a main distributing valve from a pressure oil tank; the main distributing valve is connected with a first servomotor and a second servomotor, the first servomotor and the second servomotor are both connected to the control ring, and the main distributing valve is further connected to the oil collecting tank through a cavity closing oil return pipeline. The isolating valve is further connected with a control valve, the control valve is provided with an oil supply port P, an oil return port T, a first working port A and a second working port B, the oil return port T is connected to the oil collecting groove through an oil discharge main pipeline, the first working port A is communicated with a closed piston cavity of the isolating valve, and the second working port B is communicated with an open piston cavity of the isolating valve; whether the isolating valve has an inner leakage fault or not can be quickly and conveniently determined by detecting whether the oil discharge main pipeline leaks oil or not.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical design of hydraulic systems, and particularly to a hydraulic system structure capable of detecting internal leakage of an isolation valve and an internal leakage detection method. Background Art

[0002] As a key actuator of a hydroturbine governor, the mechanical part of a power station hydraulic system generally consists of four major parts: an energy storage device, an energy supply unit, a hydraulic control component, and an actuator. The energy storage device includes a pressure oil tank and a pressure gas tank, which are used to store and regulate the pressure energy required by the system; the energy supply unit consists of an oil pump motor set and auxiliary components such as a combined valve, and is responsible for realizing the continuous cyclic supply of pressure oil; the hydraulic control component includes core control elements such as a main distribution valve, a stepping motor type conversion device, a servo proportional valve, and an emergency distribution valve, which precisely regulate the system pressure, flow rate, and direction; finally, the guide vane opening adjustment function is completed through a double servomotor actuator.

[0003] During the long-term operation of the above system, the isolation valves in the main oil supply line and the oil source line of the main distribution valve are prone to internal leakage faults due to valve core wear, seal aging, or oil contamination. Such defects will significantly reduce the volumetric efficiency of the system, resulting in a decline in the control accuracy of the governor and deterioration of the response characteristics.

[0004] In the prior art, the detection of internal leakage of the isolation valve mainly relies on regular shutdown and disassembly or indirect judgment through system pressure fluctuation analysis. However, disassembly detection is not only time-consuming and laborious, but also difficult to reflect the on-line working state of the valve in real time; and the monitoring method based on pressure parameters is greatly interfered by working conditions and cannot accurately distinguish the degree of internal leakage from the influence of load disturbance. More importantly, the undetected internal leakage fault may cause unplanned shutdown of the speed control system, and even lead to instability of unit regulation, threatening the safe operation of the power station. Summary of the Invention

[0005] The purpose of the present invention is to make the detection process of internal leakage of the isolation valve be realized in a more intuitive and convenient way through the adaptive improvement of the hydraulic system structure, so as to solve the problem of the time-consuming and laborious limitation of the existing detection methods. Therefore, the present invention proposes a hydraulic system structure capable of detecting internal leakage of the isolation valve and an internal leakage detection method, which can enable the hydraulic system of the governor to have a complete implementation process of normal shutdown and emergency shutdown, and check the internal leakage situation of the isolation valve therein, and can quickly judge the degree of internal leakage.

[0006] The present invention adopts the following technical solutions to achieve the purpose:

[0007] A hydraulic system structure capable of detecting internal leakage of an isolation valve, starting from the pressure oil tank, is successively connected with an isolation valve, the oil source pipeline of the main distributor system, and the main distributor valve; the main distributor valve is respectively connected with a first servomotor and a second servomotor, and both the first servomotor and the second servomotor are connected to the control ring. The main distributor valve is also connected to the oil sump through an oil return pipeline; the isolation valve is also connected with a control valve, which has an oil supply port P, an oil return port T, a first working port A, and a second working port B. The oil return port T is connected to the oil sump through an oil discharge main pipeline, the first working port A is communicated with the closing piston cavity of the isolation valve, and the second working port B is communicated with the opening piston cavity of the isolation valve.

[0008] Specifically, the pressure oil tank is also respectively connected with a pressure gas tank and a medium-pressure gas system, and an automatic air replenishing valve is arranged on the connecting pipeline between the pressure oil tank and the medium-pressure gas system; the pressure oil tank is also connected to the oil sump through an oil discharge main pipeline.

[0009] Preferably, a first ball valve is arranged on the connecting pipeline between the pressure oil tank and the isolation valve, and a second ball valve is arranged on the oil source pipeline of the main distributor system.

[0010] Preferably, a first emergency distributor valve group and a sectional closing valve are successively arranged on the common connecting pipeline between the main distributor valve and the opening cavities of the first servomotor and the second servomotor; a second emergency distributor valve group is arranged on the common connecting pipeline between the main distributor valve and the closing cavities of the first servomotor and the second servomotor.

[0011] Specifically, the pressure oil tank is also connected to the second emergency distributor valve group through an emergency distributor oil source pipeline, and a third ball valve is arranged on the emergency distributor oil source pipeline; the first emergency distributor valve group is also connected to the oil sump through an emergency oil return pipeline; when an emergency shutdown is required, the oil fluid enters the closing cavities of the first servomotor and the second servomotor after passing through the emergency distributor oil source pipeline and the second emergency distributor valve group, pushing the control ring to move in the closing direction. The oil fluid in the opening cavities of the first servomotor and the second servomotor enters the first emergency distributor valve group and flows back to the oil sump through the emergency oil return pipeline.

[0012] Preferably, the oil source pipeline of the main distributor system is also connected to the oil sump through multiple groups of oil pump modules; each group of oil pump modules includes an oil pump inlet oil supply pipeline, an inlet filter, an oil pump, an outlet filter, and a combined valve arranged in sequence. The oil pump inlet oil supply pipeline is connected to the oil sump, and the combined valve is connected to the oil source pipeline of the main distributor system.

[0013] Specifically, the isolation valve has a main oil supply source inlet and a main pipeline pressure oil outlet. The main oil supply source inlet is connected to the pressure oil tank, and the main pipeline pressure oil outlet is connected to the oil source pipeline of the main distributor system; the isolation valve includes an isolation valve body and a valve core piston, and a spring is arranged in the valve core piston; a control oil cavity is formed between the isolation valve body and the valve core piston, and the control oil cavity is divided into a closing piston cavity and an opening piston cavity by the valve core piston.

[0014] The present invention also provides a method for detecting internal leakage in an isolation valve in a hydraulic system. The hardware structure of the hydraulic system for this method is the aforementioned hydraulic system structure. The method is as follows: By operating the control valve, the isolation valve is brought into the open state; the first ball valve and the second ball valve are closed; it is detected in the oil collecting tank whether there is oil flowing out at the connection port between the total oil discharge pipeline and the oil collecting tank. If there is oil flowing out, it is determined that there is an oil leakage fault between the closing piston chamber and the opening piston chamber of the isolation valve.

[0015] Further, when the isolation valve is in the open state and the first ball valve and the second ball valve are closed, if it is detected that there is no oil flowing out at the connection port between the total oil discharge pipeline and the oil collecting tank, then by operating the control valve, the isolation valve is brought into the closed state; after the isolation valve is in the closed state, it is detected whether the pressure of the oil source pipeline of the main distributor system rises. If the pressure rises, it is determined that there is a spool internal leakage fault in the isolation valve.

[0016] Further, after the isolation valve is in the closed state, it is detected in the oil collecting tank whether there is oil flowing out at the connection port between the total oil discharge pipeline and the oil collecting tank. If there is oil flowing out, it is determined that there is an oil leakage fault between the closing piston chamber and the opening piston chamber of the isolation valve, or between the opening piston chamber of the isolation valve and the main oil chamber.

[0017] In summary, due to the adoption of this technical solution, the beneficial effects of the present invention are as follows:

[0018] On the basis of maintaining the integrity of the original control function of the governor hydraulic system, the present invention constructs a hydraulic circuit architecture with detection capabilities, organically integrating the process of detecting internal leakage in the isolation valve with the hydraulic system structure, thereby improving the convenience and real-time nature of the detection operation. This structural improvement effectively overcomes the technical limitation that the existing detection method requires disassembling valve parts, and can successfully complete the detection of whether there is internal leakage in the isolation valve during the online operation of the system.

[0019] The present invention optimizes the layout combination and control logic of relevant components in the hydraulic system, enabling the operation of detecting internal leakage in the isolation valve to be fully carried out relying on the normal shutdown and accident shutdown processes of the governor hydraulic system, etc. It provides more convenient internal leakage detection operations for operators. The detection process does not require additional setting of special working conditions, ensuring the adaptability of the detection results and greatly shortening the detection preparation time.

[0020] The architecture of the present invention also has relatively convenient operability in improving the structure of the existing hydraulic system, and can provide reliable technical support for the condition maintenance of the hydraulic system. Since the hydraulic system has both functionality and diagnosability under this structure, it can not only improve the reliability of the operation of system equipment, but also provide basic technical conditions for the improvement of relevant fault detection processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The embodiments and technical solutions of the present invention are further described in detail by the following attached drawings, specifically including 5 figures, as follows:

[0022] Figure 1 Schematic diagram of the overall structural connection relationship of the hydraulic system of the present invention;

[0023] Figure 2 is Figure 1 Schematic enlarged view of the structure of the isolation valve part in

[0024] Figure 3 Schematic diagram of the oil leakage point between the control oil cavities when the isolation valve of the hydraulic system of the present invention is fully open;

[0025] Figure 4 Schematic diagram of the oil leakage point of the valve core when the isolation valve of the hydraulic system of the present invention is fully closed;

[0026] Figure 5 Schematic diagram of the oil leakage point between the control oil cavities and the oil leakage point between the control oil cavity and the main oil cavity when the isolation valve of the hydraulic system of the present invention is fully closed.

[0027] The meanings represented by the marks in the attached drawings are specifically as follows:

[0028] 1 - inlet filter, 2 - first oil pump, 3 - outlet filter, 4 - combined valve, 5 - oil sump, 6 - main distributor valve, 7 - first emergency distributor valve group, 8 - sectional closing valve, 9 - first servomotor, 10 - control ring, 11 - second servomotor, 12 - pressure oil tank, 13 - pressure gas tank, 14 - isolation valve, 15 - medium-pressure gas system, 16 - automatic air replenishing valve, 17 - first ball valve, 18 - main distributor system oil source pipeline, 19 - second ball valve, 20 - second emergency distributor valve group, 21 - third ball valve, 22 - emergency distributor oil source pipeline, 23 - emergency return oil pipeline, 24 - oil supply pipeline at the inlet of the oil pump, 25 - second oil pump module, 26 - third oil pump module, 27 - fourth oil pump module, 28 - total oil discharge pipeline; 30 - main oil supply source inlet, 31 - isolation valve body, 32 - valve core piston, 33 - spring, 34 - open piston cavity, 35 - closed piston cavity, 36 - main pipeline pressure oil outlet, 37 - four-way valve, 38 - control valve. Specific embodiments

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the attached drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Usually, the components of the embodiments of the present invention described and shown in the attached drawings here can be arranged and designed in various different configurations.

[0030] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0031] Embodiment 1

[0032] A hydraulic system structure capable of detecting internal leakage of an isolation valve can be referred to Figure 1 For the detailed schematic diagram of this hydraulic system structure, which is also the preferred configuration mode of this embodiment, the introduction is as follows:

[0033] Starting from the pressure oil tank 12, the hydraulic system structure is sequentially connected with an isolation valve 14, a main distributor system oil source pipeline 18, and a main distributor valve 6; the main distributor valve 6 is respectively connected with a first servomotor 9 and a second servomotor 11, both the first servomotor 9 and the second servomotor 11 are connected to the control ring 10, and the main distributor valve 6 is also connected to the oil sump 5 through an oil return pipeline (omitted in the figure). Combining Figure 2 With the enlarged schematic diagram at the isolation valve 14, the isolation valve 14 is also connected with a control valve 38. The control valve 38 has an oil supply port P, an oil return port T, a first working port A, and a second working port B. The oil return port T is connected to the oil sump 5 through an oil discharge main pipeline 28. The first working port A is communicated with the closing piston chamber 35 of the isolation valve 14, and the second working port B is communicated with the opening piston chamber 34 of the isolation valve 14.

[0034] The pressure oil tank 12 is also respectively connected with a pressure gas tank 13 and a medium-pressure gas system 15. An automatic air replenishing valve 16 is arranged on the connecting pipeline between the pressure oil tank 12 and the medium-pressure gas system 15; the pressure oil tank 12 is also connected to the oil sump 5 through an oil discharge main pipeline 28.

[0035] A first ball valve 17 is arranged on the connecting pipeline between the pressure oil tank 12 and the isolation valve 14, and a second ball valve 19 is arranged on the main distributor system oil source pipeline 18.

[0036] As the preference of this embodiment, on the common connecting pipeline between the main distributor valve 6 and the opening chambers of the first servomotor 9 and the second servomotor 11, a first emergency distributor valve group 7 and a sectional closing valve 8 are sequentially arranged; on the common connecting pipeline between the main distributor valve 6 and the closing chambers of the first servomotor 9 and the second servomotor 11, a second emergency distributor valve group 20 is arranged.

[0037] The pressure oil tank 12 is also connected to the second accident pressure distribution valve group 20 through the accident pressure distribution oil source pipeline 22, and a third ball valve 21 is provided on the accident pressure distribution oil source pipeline 22; the first accident pressure distribution valve group 7 is also connected to the oil collecting tank 5 through the accident oil return pipeline 23; when an accident shutdown is required, the oil fluid enters the closing cavities of the first servomotor 9 and the second servomotor 11 after passing through the accident pressure distribution oil source pipeline 22 and the second accident pressure distribution valve group 20, pushing the control ring 10 to move in the closing direction, and the oil fluid in the opening cavities of the first servomotor 9 and the second servomotor 11 enters the first accident pressure distribution valve group 7 and returns to the oil collecting tank 5 through the accident oil return pipeline 23.

[0038] In this embodiment, the main pressure distribution system oil source pipeline 18 is also connected to the oil collecting tank 5 through four groups of oil pump modules. Taking the first group of oil pump modules as an example, it includes an oil pump inlet oil supply pipeline 24, an inlet filter 1, a first oil pump 2, an outlet filter 3, and a combined valve 4 arranged in sequence. The oil pump inlet oil supply pipeline 24 is connected to the oil collecting tank 5, and the combined valve 4 is connected to the main pressure distribution system oil source pipeline 18. As Figure 1 shown, the other three groups of oil pump modules are the second oil pump module 25, the third oil pump module 26, and the fourth oil pump module 27 respectively.

[0039] As Figures 3 to 5 For the specific structural schematic of the isolation valve 14, the isolation valve 14 has a main oil supply source inlet 30 and a main pipeline pressure oil outlet 36. The main oil supply source inlet 30 is connected to the pressure oil tank 12, and the main pipeline pressure oil outlet 36 is connected to the main pressure distribution system oil source pipeline 18; the isolation valve 14 includes an isolation valve body 31 and a valve core piston 32, and a spring 33 is arranged in the valve core piston 32; a control oil cavity is formed between the isolation valve body 31 and the valve core piston 32, and the control oil cavity is divided into a closing piston cavity 35 and an opening piston cavity 34 by the valve core piston 32.

[0040] This embodiment will next introduce and explain in detail the details and working principles involved in the above hydraulic system structure.

[0041] Before the governor hydraulic system is used, it needs to be pressurized to 6.3 MPa. The pressurizing gas source is connected to the medium-pressure gas system 15 of the power station, and the medium-pressure air compressor of the power station is used for air supply. It is connected to the pressure gas tank 13 and the pressure oil tank 12 through the automatic air replenishing valve 16.

[0042] The operation of the governor hydraulic system is divided into two states: normal start / stop and accident shutdown. In the normal working state, when the servomotor needs to be opened, the principle is as follows: the main oil circuit sequentially goes from the pressure oil tank 12, the first ball valve 17, the isolation valve 14, the main pressure distribution system oil source pipeline 18, the second ball valve 19 to the main pressure distribution valve 6; as Figure 1Taking the opening direction as an example, when the main spool of the main servo valve 6 moves downward, it moves in the opening direction. The oil continues to pass through the first emergency servo valve group 7 and the sectional closing valve 8, and then enters the opening chambers of the first servomotor 9 and the second servomotor 11 respectively. Therefore, the first servomotor 9 and the second servomotor 11 simultaneously push the control ring 10 to move in the opening direction. The oil returning from the closing chambers of the first servomotor 9 and the second servomotor 11 passes through the second emergency servo valve group 20 to the main servo valve 6, and then returns to the oil sump 5 through the corresponding oil return pipeline (omitted in the figure) from the closing chamber of the main servo valve 6.

[0043] When the servomotor needs to be closed, the principle is as follows: The main oil circuit sequentially passes from the pressure oil tank 12, the first ball valve 17, the isolation valve 14, the main servo system oil source pipeline 18, the second ball valve 19 to the main servo valve 6; taking Figure 1 the closing direction as an example, when the main spool of the main servo valve 6 moves upward, it moves in the closing direction. The oil continues to pass through the second emergency servo valve group 20 and then enters the closing chambers of the first servomotor 9 and the second servomotor 11 respectively. Therefore, the first servomotor 9 and the second servomotor 11 simultaneously push the control ring 10 to move in the closing direction. The oil returning from the opening chambers of the first servomotor 9 and the second servomotor 11 passes through the sectional closing valve 8 and the first emergency servo valve group 7 to the main servo valve 6, and then returns to the oil sump 5 through the corresponding oil return pipeline (omitted in the figure) from the opening chamber of the main servo valve 6.

[0044] When an emergency shutdown is required, the principle is as follows: The main oil circuit starts from the pressure oil tank 12 and sequentially passes through the third ball valve 21, the emergency servo oil source pipeline 22, and the second emergency servo valve group 20, and then enters the closing chambers of the first servomotor 9 and the second servomotor 11 respectively. Since the action speed of this oil circuit is relatively fast, the first servomotor 9 and the second servomotor 11 simultaneously and quickly push the control ring 10 to move in the closing direction. The oil returning from the opening chambers of the first servomotor 9 and the second servomotor 11 passes through the sectional closing valve 8 and the first emergency servo valve group 7, and then directly returns to the oil sump 5 through the emergency oil return pipeline 23 without passing through the main servo valve 6.

[0045] Under normal working conditions, the oil sump 5 is in a non-pressure state to prepare for pumping the returned oil back to the main servo system oil source pipeline 18 and the pressure oil tank 12. Therefore, when the pressure in the main servo system oil source pipeline 18 and the pressure oil tank 12 is lower than the first set value, the first to fourth oil pump modules can be started accordingly, and each oil pump can be controlled by the system to run alternately. When the oil pump starts, it extracts oil from the oil sump 5, passes through the oil supply pipeline 24 at the oil pump inlet, the inlet filter 1, the outlet filter 3, and the combined valve 4, and then pumps it into the main servo system oil source pipeline 18, where it can be stored in the pressure oil tank 12 to ensure that the oil level and oil pressure of the main servo system are within the set range of the governor hydraulic system.

[0046] Such as Figures 3 to 5Schematic structure of the isolation valve 14. Under normal conditions, the isolation valve 14 is in Figure 3 the fully open state shown. Its main oil supply source inlet 30 is connected to the pressure oil tank 12 through the first ball valve 17, and the main pipeline pressure oil outlet 36 is connected to the main distribution system oil source pipeline 18.

[0047] Combined with Figure 2 the enlarged schematic diagram, the control valve 38 of this embodiment can be operated electromagnetically or manually, and a four-way valve 37 as shown in Figure 2 can be provided between the control valve 38 and the isolation valve 14 to further control the pipeline. The four-way valve 37 can directly determine whether the control valve 38 is put into use. Figure 2 In, the control valve 38 is in the left position. At this time, its oil supply port P is connected to the second working port B, and the oil return port T is connected to the first working port A; since the second working port B is also connected to the open piston chamber 34 of the isolation valve 14 ( Figure 2 the connecting line is omitted in), at this time the control valve 38 is controlling the isolation valve 14 to move in the opening direction until it is fully open. During the movement, the oil in the closing piston chamber 35 of the isolation valve 14 passes through the first working port A to the oil return port T and is discharged to the oil collecting tank 5 through the total oil discharge pipeline 28.

[0048] When it is necessary to close the isolation valve 14, the control valve 38 is operated to be in the right position. This side will connect its oil supply port P to the first working port A and the oil return port T to the second working port B; then, contrary to the opening situation, since the first working port A is also connected to the closing piston chamber 35 of the isolation valve 14, at this time the control valve 38 is controlling the isolation valve 14 to move in the closing direction until it is fully closed. During the movement, the oil in the opening piston chamber 34 of the isolation valve 14 passes through the second working port B to the oil return port T and is discharged to the oil collecting tank 5 through the total oil discharge pipeline 28.

[0049] During the actual use of the isolation valve 14, internal leakage problems of the isolation valve 14 are likely to occur. In the first case, the internal sealing performance of the isolation valve body 31 is not good. After the isolation valve 14 is fully closed, the oil fluid at the main oil supply source inlet 30 may leak through the valve core piston 32 to the main pipeline pressure oil outlet 36, resulting in the main distribution system oil source pipeline 18 being pressurized when it should not be pressurized. The second case is the internal leakage in the control oil chamber of the isolation valve 14, that is, the leakage between the closing piston chamber 35 and the opening piston chamber 34. This will cause the isolation valve 14 to be unable to open fully or close fully, and the phenomenon of being unable to close fully will also lead to the appearance of the first incorrect pressurization phenomenon. When the fault phenomenon appears in the traditional hydraulic system, for example, the main distribution system oil source pipeline 18 is abnormally pressurized. After excluding problems with other components, if it is considered that the isolation valve 14 may have internal leakage, the isolation valve 14 needs to be disassembled for inspection. In this embodiment, only the oil fluid condition at the connection port between the oil discharge main pipeline 28 and the oil collecting tank 5 needs to be checked to determine whether there is internal leakage. The position where the oil collecting tank 5 is located in the hydraulic system area of the hydropower station can be directly accessed by the operator for inspection. Compared with the method of disassembling the isolation valve 14, this embodiment can quickly determine whether it is an internal leakage fault of the isolation valve 14. If not, the disassembly cost can be saved.

[0050] Embodiment 2

[0051] Based on Embodiment 1, this embodiment provides a method for detecting internal leakage of the isolation valve in the hydraulic system based on its hydraulic system structure. First, by operating the control valve 38, the isolation valve 14 is in the open state, and then the first ball valve 17 and the second ball valve 19 are closed. After the movement of the isolation valve 14 stops stably, the operator enters the space where the oil collecting tank 5 is located and checks whether there is oil fluid flowing out at the connection port between the oil discharge main pipeline 28 and the oil collecting tank 5 in the oil collecting tank 5. If there is oil fluid flowing out, it is determined that there is an oil leakage fault due to oil leakage between the closing piston chamber 35 and the opening piston chamber 34 of the isolation valve 14, that is Figure 3 the part outlined by the black elliptical line frame in the figure has oil leakage. Because at this time, there should no longer be oil fluid flowing out of the oil return port T of the control valve 38 in the closing piston chamber 35, but the oil leakage causes the oil fluid in the opening piston chamber 34 to continuously flow into the closing piston chamber 35, which is reflected as the oil fluid flowing out at the connection port. Measuring the oil fluid outflow rate can also reflect the degree of oil leakage of this fault for subsequent countermeasures.

[0052] In this embodiment, when the isolation valve 14 is in the open state, after closing the first ball valve 17 and the second ball valve 19, if no oil flows out through the detection at the connection port between the total oil discharge pipeline 28 and the oil sump 5, subsequent detections can be carried out. By operating the control valve 38, the isolation valve 14 is in the closed state. When this operation is executed, the isolation valve 14 will move as much as possible in the closing direction under the action of the control valve 38. After the movement of the isolation valve 14 stops stably, the pressure of the oil source pipeline 18 of the main distributor system can be directly detected by means of a pressure gauge, a manometer, etc. If the pressure rises, it is determined that there is a spool internal leakage fault in the isolation valve 14, that is Figure 4 the part outlined by the black oval line in it has a phenomenon of poor sealing, and this fault may be only due to the breakage and wear of the spool piston 32, or it may be due to the oil leakage in the control oil chamber when the isolation valve 14 attempts to move to the fully closed state.

[0053] Therefore, when the isolation valve 14 is in the closed state and its movement stops stably, it is still detected whether there is oil flowing out at the connection port between the total oil discharge pipeline 28 and the oil sump 5 in the oil sump 5. If there is oil flowing out, it is determined that there is an oil leakage fault due to oil leakage between the closed piston chamber 35 and the open piston chamber 34 of the isolation valve 14, or between the open piston chamber 34 and the main oil chamber of the isolation valve 14, that is Figure 5 the part outlined by the black oval line in it has oil leakage. Because at this time, there should no longer be oil flowing out through the oil return port T of the control valve 38 in the open piston chamber 35, but the oil leakage causes the oil in the closed piston chamber 35 to continuously flow into the open piston chamber 34, or the oil in the main oil chamber at the main pipeline pressure oil outlet 36 penetrates into the open piston chamber 34, which is reflected as the oil flowing out at the connection port. Measuring the oil flow rate can also reflect the degree of oil leakage of this fault for subsequent countermeasures.

[0054] In this embodiment, when the operator enters the space where the oil sump 5 is located, some of the oil in it can be drained first for detection operations; if the results obtained during the entire detection process show that the isolation valve 14 has an internal leakage fault, it will be disassembled, repaired or replaced.

Claims

1. A hydraulic system structure capable of detecting internal leakage of an isolation valve, characterized in that, Starting from the self-pressure oil tank (12), a isolation valve (14), the main distribution system oil source pipeline (18), and the main distribution valve (6) are connected in sequence; the main distribution valve (6) is respectively connected to a first servomotor (9) and a second servomotor (11), both the first servomotor (9) and the second servomotor (11) are connected to the control ring (10), and the main distribution valve (6) is also connected to the oil sump (5) through an oil return pipeline; the isolation valve (14) is also connected to a control valve (38), the control valve (38) has an oil supply port P, an oil return port T, a first working port A, and a second working port B, the oil return port T is connected to the oil sump (5) through an oil discharge main pipeline (28), the first working port A is communicated with the closing piston chamber (35) of the isolation valve (14), and the second working port B is communicated with the opening piston chamber (34) of the isolation valve (14).

2. The hydraulic system structure according to claim 1, characterized in that: The pressure oil tank (12) is also respectively connected to a pressure gas tank (13) and a medium-pressure gas system (15), and an automatic air replenishing valve (16) is arranged on the connecting pipeline between the pressure oil tank (12) and the medium-pressure gas system (15); the pressure oil tank (12) is also connected to the oil sump (5) through an oil discharge main pipeline (28).

3. The hydraulic system structure according to claim 1, characterized in that: A first ball valve (17) is arranged on the connecting pipeline between the pressure oil tank (12) and the isolation valve (14), and a second ball valve (19) is arranged on the main distribution system oil source pipeline (18).

4. The hydraulic system structure according to claim 1, characterized in that: On the common connecting pipeline between the main distribution valve (6) and the opening chambers of the first servomotor (9) and the second servomotor (11), a first emergency distribution valve group (7) and a sectional closing valve (8) are arranged in sequence; on the common connecting pipeline between the main distribution valve (6) and the closing chambers of the first servomotor (9) and the second servomotor (11), a second emergency distribution valve group (20) is arranged.

5. The hydraulic system structure according to claim 4, wherein: The pressure oil tank (12) is also connected to the second emergency distribution valve group (20) through an emergency distribution oil source pipeline (22), and a third ball valve (21) is arranged on the emergency distribution oil source pipeline (22); the first emergency distribution valve group (7) is also connected to the oil sump (5) through an emergency oil return pipeline (23); when emergency shutdown is required, the oil fluid enters the closing chambers of the first servomotor (9) and the second servomotor (11) after passing through the emergency distribution oil source pipeline (22) and the second emergency distribution valve group (20), pushing the control ring (10) to move in the closing direction, and the oil fluid in the opening chambers of the first servomotor (9) and the second servomotor (11) enters the first emergency distribution valve group (7) and returns to the oil sump (5) through the emergency oil return pipeline (23).

6. The hydraulic system structure according to claim 1, wherein: The main distribution system oil source pipeline (18) is also connected to the oil sump (5) through multiple groups of oil pump modules; each group of oil pump modules includes an oil pump inlet oil supply pipeline (24), an inlet filter (1), an oil pump, an outlet filter (3), and a combined valve (4) arranged in sequence, the oil pump inlet oil supply pipeline (24) is connected to the oil sump (5), and the combined valve (4) is connected to the main distribution system oil source pipeline (18).

7. The hydraulic system structure according to claim 1, characterized in that: The isolation valve (14) has a main oil supply source inlet (30) and a main pipeline pressure oil outlet (36). The main oil supply source inlet (30) is connected to the pressure oil tank (12), and the main pipeline pressure oil outlet (36) is connected to the oil source pipeline (18) of the main distributor system; the isolation valve (14) includes an isolation valve body (31) and a spool piston (32), and a spring (33) is arranged in the spool piston (32); a control oil chamber is formed between the isolation valve body (31) and the spool piston (32), and the control oil chamber is divided into a closing piston chamber (35) and an opening piston chamber (34) by the spool piston (32).

8. A method for detecting internal leakage in an isolation valve in a hydraulic system, characterized in that, The hardware structure of the hydraulic system of this method is the hydraulic system structure described in any one of claims 1 to 7. This method is as follows: by operating the control valve (38), the isolation valve (14) is in the open state; the first ball valve (17) and the second ball valve (19) are closed; it is detected in the oil sump (5) whether there is oil flowing out at the connection port of the oil discharge main pipeline (28) and the oil sump (5). If there is oil flowing out, it is determined that there is an oil leakage fault due to oil leakage between the closing piston chamber (35) and the opening piston chamber (34) of the isolation valve (14).

9. The internal leakage detection method of the isolation valve according to claim 8, wherein: When the isolation valve (14) is in the open state and the first ball valve (17) and the second ball valve (19) are closed, if it is detected that there is no oil flowing out at the connection port of the oil discharge main pipeline (28) and the oil sump (5), then by operating the control valve (38), the isolation valve (14) is in the closed state; after the isolation valve (14) is in the closed state, it is detected whether the pressure of the oil source pipeline (18) of the main distributor system rises. If the pressure rises, it is determined that there is a spool internal leakage fault in the isolation valve (14).

10. The method for detecting internal leakage of the isolation valve according to claim 9, characterized in that: After the isolation valve (14) is in the closed state, it is detected in the oil sump (5) whether there is oil flowing out at the connection port of the oil discharge main pipeline (28) and the oil sump (5). If there is oil flowing out, it is determined that there is an oil leakage fault due to oil leakage between the closing piston chamber (35) and the opening piston chamber (34) of the isolation valve (14), or between the opening piston chamber (34) of the isolation valve (14) and the main oil chamber.

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