Independent testing device for deep sea steady-state performance of hydraulic valve and testing method thereof

Abstract

The invention discloses an independent testing device for deep sea steady-state performance of a hydraulic valve and a testing method thereof, and belongs to the technical field of hydraulic element testing. An oil inlet of the hydraulic pump is connected with an oil tank through a filter, the motor is connected with the hydraulic pump through a coupler, and an oil outlet of the hydraulic pump is connected with a one-way valve. A branch connected with an oil outlet of the one-way valve is sequentially connected with a safety valve and a first throttle valve and returns to the oil tank; a second stop valve, a tested hydraulic valve, a high-pressure flow meter, a third stop valve, a second throttling valve, a back pressure valve and a third throttling valve are sequentially connected into a main oil path connected with an oil outlet of the one-way valve and finally return to the oil tank; an oil inlet and an oil outlet of the tested hydraulic valve and an oil outlet of the second throttle valve are connected with a pressure gauge; the tested hydraulic valve is positioned in the pressure container; the oil outlet of the one-way valve is further connected with the oil outlet of the second throttling valve through a first stop valve. The back pressure valve is connected with a fourth stop valve in parallel. The problem that performance parameters of the hydraulic valve are difficult to test in a deep sea ultrahigh pressure environment is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic component testing, and in particular to an independent testing device and a testing method for deep-sea steady-state performance of a hydraulic valve. Background Art

[0002] The deep sea is not only a treasure trove of resources, but also a frontier of scientific and technological innovation. However, the extreme conditions of the deep sea environment pose unprecedented challenges to the performance and reliability of deep sea hydraulic components. Under the ultra-high external pressure environment of the deep sea, the clearance between the hydraulic valve pairs, the compression of the seals, and the viscosity of the working medium change, resulting in significant changes in leakage and flow characteristics compared to those in the land environment.

[0003] At present, only a series of test standards have been formulated for the steady-state performance of hydraulic valves on land at home and abroad. For example, "JB / T10374-2013" stipulates the basic parameters, test methods and other requirements of hydraulic relief valves; "GB / T 8104-1987" formulates the test methods for the steady-state performance and transient performance of flow control valves. The existing land test methods cannot simulate the real environmental conditions of the deep sea, and some performance parameters are difficult to obtain under high-pressure environments. Therefore, it is impossible to directly use the existing land test methods to accurately measure and evaluate the deep-sea steady-state performance of hydraulic valves. In addition, the existing standards only provide a test system for a single hydraulic valve, and there is no universal test system suitable for deep-sea steady-state performance testing of hydraulic valves. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art. A pressure vessel is used to simulate the actual working conditions of the tested hydraulic valve in the deep sea. The key indicators of the tested hydraulic valve are measured by hydraulic components such as back pressure valves, throttle valves, high and low pressure flow meters, and an independent test device and a test method for the deep-sea steady-state performance of a hydraulic valve are provided.

[0005] The technical principle is:

[0006] 1. Deep-sea equipment usually uses pressure compensators to transfer the pressure of seawater to the hydraulic system, so the hydraulic components are subjected to high external pressure and high back pressure at the same time. In order to simulate the actual working conditions of the tested hydraulic valve, the tested hydraulic valve is placed in a pressure vessel through the cabin, and the pressure vessel is pressurized by an independent pump station; in addition, a back pressure valve and a throttle valve are added at the return oil, and the two valves are adjusted to make the system back pressure the preset deep-sea simulation pressure.

[0007] 2. In view of the ultra-high back pressure of deep-sea hydraulic systems, it is impossible to use a measuring cylinder to measure the internal leakage at the oil outlet of the tested hydraulic valve as in onshore testing. Therefore, a stop valve is introduced into the hydraulic circuit. When the third stop valve is closed, when internal leakage occurs, the pressure in the pipeline between the outlet of the tested hydraulic valve and the third stop valve increases, and the second pressure indicator rises. The internal leakage of the tested valve ΔV can be calculated by formula (1):

[0008]

[0009] Where: V0 is the volume of the oil pipe between the outlet of the tested hydraulic valve and the third stop valve, Δp is the change in the indication of the second pressure gauge, and K is the bulk elastic modulus of the oil.

[0010] In order to ensure the test accuracy of internal leakage, the pressure change value of the pipeline between the outlet of the tested hydraulic valve and the third stop valve must be controlled within a certain period of time so as not to exceed 5% of the rated pressure of the tested hydraulic valve. At this time, the bulk elastic modulus K can be considered as a constant.

[0011] 3. The flow rate through the tested hydraulic valve can be measured by a high-pressure flow meter. However, if conditions do not allow (the flow meter is not resistant to ultra-high pressure), it can be indirectly measured by a low-pressure flow meter. The specific calculation method is as shown in formula (2):

[0012] q v,实 =C(p,T)q v,测 (2)

[0013] Where: q v,测 The correction factor C(p,T) is a function related to pressure and temperature.

[0014] The specific technical solution is:

[0015] First, the present invention provides an independent test device for the deep-sea steady-state performance of a hydraulic valve, including an oil tank, a filter, a motor, a hydraulic pump, a one-way valve, a safety valve, a first throttle valve, a first stop valve, a second stop valve, a first pressure gauge, a pressure vessel, a tested hydraulic valve, a second pressure gauge, a high-pressure flow meter, a third stop valve, a second throttle valve, a third pressure gauge, a back pressure valve, a fourth stop valve, a third throttle valve, and a low-pressure flow meter;

[0016] The oil inlet of the hydraulic pump is connected to the oil tank via a filter, the motor and the hydraulic pump are connected via a coupling, and the oil outlet of the hydraulic pump is connected to a one-way valve;

[0017] The branch connected to the oil outlet of the one-way valve is connected with a safety valve and a first throttle valve in sequence and returns to the oil tank;

[0018] The main oil circuit connected to the oil outlet of the one-way valve is connected with the second stop valve, the tested hydraulic valve, the high-pressure flow meter, the third stop valve, the second throttle valve, the back pressure valve and the third throttle valve in sequence, and finally returns to the oil tank; the oil inlet and the oil outlet of the tested hydraulic valve are connected with the first pressure gauge and the second pressure gauge respectively; the oil outlet of the second throttle valve is connected with the third pressure gauge; the tested hydraulic valve is located in the pressure vessel;

[0019] The oil outlet of the one-way valve is also connected to the oil outlet of the second throttle valve via a first stop valve;

[0020] The back pressure valve is also connected in parallel with a fourth stop valve.

[0021] The pressure vessel is a miniaturized device, and its inner cavity can only accommodate the tested hydraulic valve. The internal pressure of the pressure vessel is controlled by an independent pump source.

[0022] Furthermore, the low-pressure flowmeter can replace the high-pressure flowmeter, and the low-pressure flowmeter is connected to the oil return port of the third throttle valve.

[0023] Secondly, the present invention provides an independent test method for the deep-sea steady-state performance of a hydraulic valve, using the independent test device for the deep-sea steady-state performance of a hydraulic valve; the method includes the following process:

[0024] Close the first stop valve and the fourth stop valve, start the motor, set the speed of the hydraulic pump to the lowest working speed, gradually increase the pressure in the pressure vessel, and adjust the safety valve and the back pressure valve at the same time to gradually increase the outlet pressure of the tested hydraulic valve. In this process, control the pressure growth rate inside the pressure vessel to avoid excessive pressure difference between it and the third pressure gauge;

[0025] When the reading of the third pressure gauge is equal to the expected simulated deep-sea environmental pressure, stop adjusting the back pressure valve; by adjusting the speed of the motor, the set pressure of the safety valve and the opening of the second throttle valve, the pressure and flow control of the tested hydraulic valve are achieved to complete the steady-state performance test;

[0026] In addition, the first stop valve is opened, and the second throttle valve and the back pressure valve are adjusted at the same time to achieve oil flow in the reverse direction; when conducting an internal leakage test, the third stop valve is closed, and the pressure difference change of the second pressure gauge within the set time is recorded, and the internal leakage amount is calculated based on formula (1);

[0027] After the test, gradually release the pressure from the pressure vessel and adjust the back pressure valve at the same time to make the indication of the third pressure gauge equal to the pressure inside the pressure vessel. During this process, the rate of decrease of the pressure inside the pressure vessel should be controlled to avoid excessive pressure difference between it and the third pressure gauge. When the system back pressure drops to the lower limit of the back pressure valve, open the fourth stop valve to complete the pressure relief.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. By adding hydraulic components such as pressure vessels and back pressure valves, the actual working conditions of the tested hydraulic valve in the deep sea can be simulated, providing a strong guarantee for accurately testing the deep-sea steady-state performance of the tested hydraulic valve.

[0030] 2. In combination with the stop valve, the internal leakage of the tested hydraulic valve under deep sea conditions can be accurately calculated by the formula.

[0031] 3. In view of the situation that the flow meter cannot withstand ultra-high pressure, the low-pressure flow meter on the low-pressure side is used to indirectly measure the flow on the high-pressure side to complete the measurement of the flow through the tested hydraulic valve.

[0032] 4. The test system provided by the present invention can be applied to deep-sea steady-state performance tests of various hydraulic valves, and can significantly reduce the testing cost of deep-sea hydraulic valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a system circuit diagram of the present invention;

[0034] Figure 2 is the inlet pressure-internal leakage characteristic curve of the tested relief valve measured by the present invention;

[0035] Figure 3 is the steady-state pressure-flow characteristic curve of the tested relief valve measured by the present invention;

[0036] Explanation of the accompanying drawings: 1. Oil tank; 2. Filter; 3. Motor; 4. Hydraulic pump; 5. Check valve; 6. Safety valve; 7. First throttle valve; 8. First stop valve; 9. Second stop valve; 10. First pressure gauge; 11. Pressure vessel; 12. Test hydraulic valve; 13. Second pressure gauge; 14. High-pressure flowmeter; 15. Third stop valve; 16. Second throttle valve; 17. Third pressure gauge; 18. Back-pressure valve; 19. Fourth stop valve; 20. Third throttle valve; 21. Low-pressure flowmeter. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions and advantages of the present invention more clear, the following will be combined with the attached Figure 1 The technical scheme of the present invention is clearly and completely described in the specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] See also Figure 1The present invention provides an independent testing device for the deep-sea steady-state performance of a hydraulic valve, comprising an oil tank 1, a filter 2, a motor 3, a hydraulic pump 4, a one-way valve 5, a safety valve 6, a first throttle valve 7, a first stop valve 8, a second stop valve 9, a first pressure gauge 10, a pressure vessel 11, a tested hydraulic valve 12, a second pressure gauge 13, a high-pressure flowmeter 14, a third stop valve 15, a second throttle valve 16, a third pressure gauge 17, a back-pressure valve 18, a fourth stop valve 19, a third throttle valve 20, and a low-pressure flowmeter 21.

[0039] The oil inlet of the hydraulic pump 4 is connected to the oil tank 1 via the filter 2, and the motor 3 is connected to the hydraulic pump 4 via a coupling. By controlling the speed of the motor 3, the flow control of the hydraulic pump 4 can be achieved. A one-way valve 5 is connected to the hydraulic pump 4 to prevent the oil from flowing back and causing damage to the hydraulic pump 4; the branch connected to the oil outlet of the one-way valve 5 is connected to the safety valve 6 and the first throttle valve 7 in sequence and returns to the oil tank 1. The first throttle valve 7 is used to reduce the pressure of the overflow liquid at the oil return port; the main oil circuit connected to the oil outlet of the one-way valve 5 A second stop valve 9 and a first pressure gauge 10 are connected. The first pressure gauge 10 is connected to the oil inlet of the tested hydraulic valve 12. The oil outlet of the tested hydraulic valve 12 is sequentially connected to the second pressure gauge 13, the high-pressure flow meter 14, the third stop valve 15, and the second throttle valve 16. The first pressure gauge 10 and the second pressure gauge 13 monitor the pressure changes at the oil inlet and outlet of the tested hydraulic valve 12 in real time. In conjunction with the second stop valve 9 and the third stop valve 15, it can be detected whether the inlet and outlet connections of the tested hydraulic valve 12 are in good condition.

[0040] In addition, only the third stop valve 15 is closed to perform an internal leakage test. The second throttle valve 16 is used to adjust the pressure at the outlet of the tested hydraulic valve 12. The oil outlet of the second throttle valve 16 is connected to the oil inlet of the back pressure valve 18 via the third pressure gauge 17. The back pressure valve 18 is used to establish a high back pressure. The pressure regulating device of the back pressure valve 18 is adjusted and combined with the third pressure gauge 17 to simulate ultra-high back pressure environments at different sea depths. The back pressure valve 18 is connected to the third throttle valve 20 and finally returns to the oil tank 1.

[0041] The first stop valve 8 is connected between the oil outlet of the one-way valve 5 and the oil outlet of the second throttle valve 16, and its function is to change the oil flow direction.

[0042] The pressure vessel 11 is a miniaturized device, and its inner cavity can only accommodate the tested hydraulic valve 12, which can effectively reduce the manufacturing cost of the test device, and the remaining hydraulic components are placed outside the pressure vessel 11, which increases the operability of the test.

[0043] The internal pressure of the pressure vessel 11 is controlled by an independent pump source.

[0044] The back pressure valve 18 is connected in parallel with the fourth stop valve 19 to test the system pressure relief.

[0045] The low-pressure flowmeter 21 is connected to the oil return port of the third throttle valve 20 and is used to replace the high-pressure flowmeter 14. When the test conditions do not allow, the reading of the high-pressure flowmeter 14 is indirectly measured by formula (2).

[0046] The test method of the present invention is as follows: close the first stop valve 8 and the fourth stop valve 19, start the motor 3, set the speed of the hydraulic pump 4 to the minimum working speed, gradually pressurize the pressure vessel 11 (such as 5MPa, 10MPa, 20MPa, 30MPa...), and adjust the safety valve 6 and the back pressure valve 18 at the same time, so that the outlet pressure of the tested hydraulic valve 12 gradually increases (such as 5MPa, 10MPa, 20MPa, 30MPa...), and in this process, the pressure growth rate inside the pressure vessel 11 should be controlled to avoid excessive pressure difference between it and the third pressure gauge 17. When the reading of the third pressure gauge 17 is equal to the expected simulated deep sea environmental pressure, stop adjusting the back pressure valve 18. By adjusting the speed of the motor 3, the set pressure of the safety valve 6, and the opening of the second throttle valve 16, etc., the pressure and flow control of the tested hydraulic valve 12 is realized, and the steady-state performance test is completed. In addition, the first stop valve 8 is opened, and the second throttle valve 16 and the back pressure valve 18 are adjusted at the same time to achieve reverse oil flow. When conducting an internal leakage test, the third stop valve 15 needs to be closed, the pressure difference change of the second pressure gauge 13 within a certain period of time needs to be recorded, and the internal leakage amount needs to be calculated based on formula (1). After the test, the pressure vessel 11 is gradually depressurized, and the back pressure valve 18 is adjusted at the same time to make the reading of the third pressure gauge 17 equal to the pressure in the cavity of the pressure vessel 11. During this process, the rate of decrease of the internal pressure of the pressure vessel 11 should be controlled to avoid excessive pressure difference between it and the third pressure gauge 17. When the system back pressure drops to the lower limit of the pressure adjustment of the back pressure valve 18, the fourth stop valve 19 is opened to complete the pressure relief.

[0047] This embodiment uses the deep-sea steady-state performance test of the relief valve:

[0048] The overflow valve is connected to the test circuit as the tested hydraulic valve 12, and the preparations before the test are made according to the present invention, until the safety valve 6 and the back pressure valve 18 are adjusted so that the reading of the third pressure gauge 17 is the same as the pressure in the cavity of the pressure vessel 11 (both are the expected simulated deep-sea environmental pressures).

[0049] 1) Upper limit of pressure regulation range and pressure stability: Continue to adjust the safety valve 6 to the sum of 1.15 times the upper limit of the pressure regulation range of the tested hydraulic valve 12 and the expected simulated deep-sea environmental pressure, increase the rotation speed of the hydraulic pump 4, and gradually increase the flow through the tested hydraulic valve 12 to the test flow. Use the first pressure gauge 10 to measure the upper limit of the pressure regulation range of the tested hydraulic valve 12, and record the pressure swing value within 1 minute and the pressure offset value within 1 minute.

[0050] 2) Internal leakage: adjust the safety valve 6 so that the system pressure is the sum of 0.75 times the upper limit of the pressure regulating range of the tested hydraulic valve 12 and the expected simulated deep-sea environmental pressure, close the third stop valve 15, and after setting for 1 minute, indirectly measure the internal leakage of the tested hydraulic valve 12 through the change in the indication of the second pressure gauge 13. In the process of measuring the internal leakage, the inlet pressure of the tested hydraulic valve 12 is gradually reduced from the sum of 0.75 times the upper limit of the pressure regulating range and the expected simulated deep-sea environmental pressure to the minimum working pressure of the system. During this period, several measuring points are set (the number of measuring points set should be sufficient to draw a curve), and the internal leakage of the tested hydraulic valve 12 is measured point by point, and the inlet pressure-internal leakage characteristic curve is drawn, see Figure 2 .

[0051] 3) Steady-state pressure-flow characteristics: adjust the safety valve 6 to the sum of 1.15 times the upper limit of the pressure regulating range of the tested hydraulic valve 12 and the expected simulated deep-sea environmental pressure, and make the flow through the test relief valve 12 the test flow, and conduct the following tests respectively:

[0052] ① Adjust the safety valve 6 to gradually reduce the system pressure. When the reading of the high-pressure flowmeter 14 drops to 1% of the test flow of the tested hydraulic valve 12, the difference between the reading of the first pressure gauge 10 and the expected simulated deep-sea environmental pressure is the closing pressure of the tested hydraulic valve 12;

[0053] ② Adjust the safety valve 6 to gradually increase the system pressure. When the reading of the high-pressure flowmeter 14 increases from 0 to 1% of the test flow of the tested hydraulic valve 12, the difference between the reading of the first pressure gauge 10 and the expected simulated deep-sea environmental pressure is the opening pressure of the tested hydraulic valve 12. During the steady-state pressure-flow characteristic test, change the system pressure, measure the inlet pressure of the tested hydraulic valve 12 and the flow through the tested hydraulic valve 12 under the corresponding pressure point by point (the set number of measurement points should be sufficient to draw the curve), and draw the steady-state pressure-flow characteristic curve, see Figure 3 .

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An independent test device for the deep-sea steady-state performance of a hydraulic valve, characterized in that: It comprises an oil tank (1), a hydraulic pump (4), and a tested hydraulic valve (12); The oil inlet of the hydraulic pump (4) is connected to the oil tank (1) via the filter (2), the motor (3) is connected to the hydraulic pump (4) via a coupling, and the oil outlet of the hydraulic pump (4) is connected to a one-way valve (5); The branch connected to the oil outlet of the one-way valve (5) is connected in sequence to a safety valve (6) and a first throttle valve (7) and returns to the oil tank (1); The main oil circuit connected to the oil outlet of the one-way valve (5) is connected in sequence to a second stop valve (9), a tested hydraulic valve (12), a high-pressure flow meter (14), a third stop valve (15), a second throttle valve (16), a back pressure valve (18) and a third throttle valve (20), and finally returns to the oil tank (1); the oil inlet and the oil outlet of the tested hydraulic valve (12) are connected to a first pressure gauge (10) and a second pressure gauge (13) respectively; the oil outlet of the second throttle valve (16) is connected to a third pressure gauge (17); the tested hydraulic valve (12) is located in a pressure container (11); The oil outlet of the one-way valve (5) is also connected to the oil outlet of the second throttle valve (16) via a first stop valve (8); The back pressure valve (18) is also connected in parallel with a fourth stop valve (19).

2. An independent test device for deep-sea steady-state performance of hydraulic valves according to claim 1, characterized in that: It also comprises a pressure container (11), the inner cavity of which can only accommodate the tested hydraulic valve (12).

3. An independent test device for deep-sea steady-state performance of hydraulic valves according to claim 2, characterized in that: The internal pressure of the pressure container (11) is controlled by an independent pump source.

4. The independent testing device for deep-sea steady-state performance of hydraulic valves according to claim 1, characterized in that: It also includes a low-pressure flow meter (21), which is connected to the oil return port of the third throttle valve (20); when the high-pressure flow meter (14) cannot be used, the low-pressure flow meter (21) is used to calculate the actual flow.

5. An independent test method for the deep-sea steady-state performance of a hydraulic valve, characterized in that: An independent testing device for deep-sea steady-state performance of a hydraulic valve according to any one of claims 1 to 4 is used; the method comprises the following process: The first stop valve (8) and the fourth stop valve (19) are closed, the motor (3) is started, the speed of the hydraulic pump (4) is set to the minimum operating speed, and pressure is gradually added to the pressure container (11). At the same time, the safety valve (6) and the back pressure valve (18) are adjusted to gradually increase the outlet pressure of the tested hydraulic valve (12). During this process, the pressure growth rate inside the pressure container (11) is controlled to avoid excessive pressure difference between the pressure container (11) and the third pressure gauge (17); When the reading of the third pressure gauge (17) is equal to the expected simulated deep-sea environmental pressure, the back pressure valve (18) is stopped from being adjusted; by adjusting the rotation speed of the motor (3), the set pressure of the safety valve (6) and the opening of the second throttle valve (16), the pressure and flow control of the tested hydraulic valve (12) is achieved, thereby completing the steady-state performance test; In addition, the first stop valve (8) is opened, and the second throttle valve (16) and the back pressure valve (18) are adjusted at the same time to achieve oil flow in the reverse direction; when conducting an internal leakage test, the third stop valve (15) is closed, and the pressure difference change of the second pressure gauge (13) within a set time is recorded, and the internal leakage amount is calculated based on formula (1): Wherein: V0 is the volume of the oil pipe between the outlet of the tested hydraulic valve (12) and the third stop valve (15), Δp is the change in the indication of the second pressure gauge (13), and K is the bulk elastic modulus of the oil; After the test is completed, the pressure vessel (11) is gradually depressurized and the back pressure valve (18) is adjusted at the same time so that the reading of the third pressure gauge (17) is equal to the pressure in the cavity of the pressure vessel (11). During this process, the decreasing rate of the pressure inside the pressure vessel (11) should be controlled to avoid excessive pressure difference between the pressure inside the pressure vessel (11) and the third pressure gauge (17). When the system back pressure drops to the lower pressure limit of the back pressure valve (18), the fourth stop valve (19) is opened to complete the pressure relief.

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