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

Abstract

The application discloses a kind of independent testing device and testing method of hydraulic valve deep-sea steady-state performance, belong to hydraulic component testing technical field;The oil inlet of hydraulic pump is connected with oil tank through filter, motor is connected with hydraulic pump through shaft coupling, and one-way valve is connected to the oil outlet of hydraulic pump;Safety valve, first throttle valve are sequentially connected in branch connected with the oil outlet of one-way valve and return to oil tank;Second stop valve, the hydraulic valve of being tested, high-pressure flowmeter, third stop valve, second throttle valve, back pressure valve and third throttle valve are sequentially connected in main oil circuit connected with the oil outlet of one-way valve and finally return to oil tank;The oil inlet and oil outlet of the hydraulic valve of being tested and the oil outlet of second throttle valve are all connected with pressure gauge;The hydraulic valve of being tested is located in pressure vessel;The oil outlet of one-way valve is also connected with the oil outlet of second throttle valve through first stop valve;Back pressure valve is connected with fourth stop valve in parallel.The application solves the problem that the performance parameter of hydraulic valve is difficult to test under deep-sea superhigh pressure environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic element testing, in particular to a deep-sea steady-state performance independent testing device for hydraulic valves and a testing method thereof. BACKGROUND

[0002] Deep sea is not only a treasure trove of resources, but also a frontier field of scientific and technological innovation. However, the extreme conditions of deep-sea environment pose unprecedented challenges to the performance and reliability of deep-sea hydraulic elements. Under the environment of deep-sea super-high external pressure, the clearance between the valve pair, the compression amount of the sealing element and the viscosity of the working medium change, resulting in great changes in leakage, flow characteristics and other aspects compared with the land environment.

[0003] At present, only the land steady-state performance of hydraulic valves has been formulated a series of testing standards at home and abroad, such as JB / T10374-2013 which stipulates the basic parameters, test methods and other requirements of hydraulic overflow valve; GB / T 8104-1987 which formulates the test method for steady-state performance and transient performance of flow control valve. The existing land testing method cannot simulate the real environment working condition of deep sea, and some performance parameters are difficult to obtain in high pressure environment. Therefore, the existing land testing method cannot be directly used for accurate measurement and evaluation of the deep-sea steady-state performance of hydraulic valves. In addition, the existing standard only provides a test system for a single hydraulic valve, and there is no universal test system suitable for deep-sea steady-state performance test of hydraulic valves. SUMMARY

[0004] The purpose of the present application is to overcome the problems in the prior art, to simulate the real working condition of the test hydraulic valve in deep sea by using a pressure vessel, to measure the key indicators of the test hydraulic valve by using back pressure valve, throttle valve and high and low pressure flow meters, and to provide an independent testing device for deep-sea steady-state performance of hydraulic valves and a testing method thereof.

[0005] The technical principle is:

[0006] 1. Deep-sea equipment usually uses a pressure compensator to transfer the pressure of seawater to the inside of the hydraulic system, so the hydraulic elements bear high external pressure and high back pressure at the same time. In order to simulate the real working condition of the test hydraulic valve, the test hydraulic valve is placed in the pressure vessel, 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 oil return, and the system back pressure is adjusted to the preset deep-sea simulation pressure.

[0007] 2. Given the extremely high back pressure in deep-sea hydraulic systems, it is impossible to measure internal leakage at the outlet of the tested hydraulic valve using a measuring cylinder as in land-based tests. Therefore, a shut-off valve is introduced into the hydraulic circuit. When the third shut-off valve is closed, the pressure in the pipeline between the outlet of the tested hydraulic valve and the third shut-off valve increases when internal leakage occurs, causing the second pressure gauge reading to rise. The internal leakage amount ΔV of the tested valve can be calculated using formula (1):

[0008]

[0009] In the formula: V0 is the volume of the oil pipe between the outlet of the tested hydraulic valve and the third shut-off valve, Δp is the change in the reading of the second pressure gauge, and K is the bulk modulus of the oil.

[0010] To ensure the accuracy of the internal leakage test, the pressure change in the pipeline between the outlet of the tested hydraulic valve and the third shut-off valve must be controlled to not exceed 5% of the rated pressure of the tested hydraulic valve within a certain period of time. At this time, the bulk modulus K can be considered a constant.

[0011] 3. The flow rate through the tested hydraulic valve can be measured by a high-pressure flow meter, but if conditions do not permit (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 shown in formula (2):

[0012] q v,实 =C(p,T)q v,测 (2)

[0013] In the formula: q v,测 For the measured value of the low-pressure flow meter, the correction factor C(p,T) is a function related to pressure and temperature.

[0014] The specific technical solution is as follows:

[0015] First, the present invention provides an independent testing device for the deep-sea steady-state performance of hydraulic valves, including an oil tank, a filter, a motor, a hydraulic pump, a check valve, a safety valve, a first throttle valve, a first shut-off valve, a second shut-off valve, a first pressure gauge, a pressure vessel, a hydraulic valve under test, a second pressure gauge, a high-pressure flow meter, a third shut-off valve, a second throttle valve, a third pressure gauge, a back pressure valve, a fourth shut-off 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 is connected to the hydraulic pump via a coupling, and the oil outlet of the hydraulic pump is connected to a check valve.

[0017] A safety valve and a first throttle valve are connected in sequence to the branch connected to the oil outlet of the check valve and then return to the oil tank.

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

[0019] The oil outlet of the one-way valve is also connected with the oil outlet of the second throttle valve through the first stop valve.

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

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

[0022] Further, the low-pressure flow meter can replace the high-pressure flow meter, and the low-pressure flow meter is connected at the oil return port of the third throttle valve.

[0023] Secondly, the application provides an independent testing method for the deep-sea steady-state performance of a hydraulic valve, which adopts the independent testing device for the deep-sea steady-state performance of a hydraulic valve; the method comprises the following processes:

[0024] The first stop valve and the fourth stop valve are closed, the motor is started, the rotating speed of the hydraulic pump is set to the lowest working rotating speed, the pressure in the pressure container is gradually increased, the safety valve and the back pressure valve are adjusted, the outlet pressure of the test hydraulic valve is gradually increased, the pressure growth rate in the pressure container is controlled in this process, and the pressure difference between the pressure container and the third pressure gauge is prevented from being too large.

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

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

[0027] After the test is completed, the pressure in the pressure container is gradually released, the back pressure valve is adjusted, the reading of the third pressure gauge is equal to the pressure in the cavity of the pressure container, the pressure drop rate in the pressure container is controlled in this process, and the pressure difference between the pressure container and the third pressure gauge is prevented from being too large; when the system back pressure drops to the lower limit of the pressure adjustment of the back pressure valve, the fourth stop valve is opened, and the pressure relief is completed.

[0028] Compared with the prior art, the present application has the beneficial effects of:

[0029] 1. By adding pressure vessels, back pressure valves and other hydraulic elements, the real working conditions of the test hydraulic valve in deep sea can be simulated, thereby providing a powerful guarantee for accurately testing the deep sea steady state performance of the test hydraulic valve.

[0030] 2. In cooperation with the stop valve, the internal leakage of the test hydraulic valve under deep sea working conditions can be accurately calculated through a formula.

[0031] 3. In view of the fact that the flow meter is not resistant to super high pressure, the high pressure side flow is indirectly measured and calculated by using the low pressure flow meter on the low pressure side, so as to complete the measurement of the flow through the test hydraulic valve.

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

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

[0034] Figure 2 is the measured inlet pressure-internal leakage characteristic curve of the test overflow valve;

[0035] Figure 3 is the measured steady state pressure-flow characteristic curve of the test overflow valve;

[0036] BRIEF DESCRIPTION OF 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 flow meter; 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 flow meter. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described below in conjunction with the drawings Figure 1 and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0038] Please refer to Figure 1The application provides a kind of independent testing device for deep-sea steady-state performance of hydraulic valve, comprising oil tank 1, filter 2, motor 3, hydraulic pump 4, check valve 5, safety valve 6, first throttle valve 7, first stop valve 8, second stop valve 9, first pressure gauge 10, pressure vessel 11, test hydraulic valve 12, second pressure gauge 13, high-pressure flowmeter 14, third stop valve 15, second throttle valve 16, third pressure gauge 17, back pressure valve 18, fourth stop valve 19, third throttle valve 20, low-pressure flowmeter 21.

[0039] The oil inlet of hydraulic pump 4 is connected with oil tank 1 through filter 2, motor 3 is connected with hydraulic pump 4 through shaft coupling, the flow of hydraulic pump 4 can be controlled by controlling the rotating speed of motor 3, check valve 5 is connected behind hydraulic pump 4, which is used to avoid the damage of oil backflow to hydraulic pump 4; the branch connected with the oil outlet of check valve 5 is connected with safety valve 6 and first throttle valve 7 in sequence and returns to oil tank 1, first throttle valve 7 is used to reduce the pressure of overflow liquid at the oil return port; the main oil circuit connected with the oil outlet of check valve 5 is connected with second stop valve 9 and first pressure gauge 10, the oil inlet of test hydraulic valve 12 is connected with first pressure gauge 10, the oil outlet of test hydraulic valve 12 is connected with second pressure gauge 13, high-pressure flowmeter 14, third stop valve 15 and second throttle valve 16 in sequence, first pressure gauge 10 and second pressure gauge 13 monitor the pressure change at the oil inlet and outlet of test hydraulic valve 12 in real time, and second stop valve 9 and third stop valve 15 can detect whether the connection of inlet and outlet of test hydraulic valve 12 is good.

[0040] In addition, only third stop valve 15 is closed, internal leakage test can be carried out, second throttle valve 16 is used to adjust the pressure at the outlet of test hydraulic valve 12, the oil outlet of second throttle valve 16 is connected with the oil inlet of back pressure valve 18 through third pressure gauge 17, back pressure valve 18 is used to establish high back pressure, the pressure adjusting device of back pressure valve 18 is adjusted, and third pressure gauge 17 can be used to simulate the super-high back pressure environment at different sea depths, back pressure valve 18 is connected with third throttle valve 20 in sequence, and finally returns to oil tank 1.

[0041] First stop valve 8 is connected between the oil outlet of check valve 5 and the oil outlet of second throttle valve 16, which is used to change the oil direction.

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

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

[0044] Back pressure valve 18 and fourth stop valve 19 are connected in parallel, which is used to test the pressure relief of system.

[0045] Low pressure flow meter 21 is connected to the oil return port of third throttle valve 20, used to replace high pressure flow meter 14, when the test conditions are not allowed, through formula (2) indirect measurement of high pressure flow meter 14's indication.

[0046] The test method of the present application is: close first stop valve 8 and fourth stop valve 19, start motor 3, set the speed of hydraulic pump 4 to the lowest working speed, gradually pressurize the pressure vessel 11 (such as 5MPa, 10MPa, 20MPa, 30MPa…), while adjusting the safety valve 6 and the back pressure valve 18, the outlet pressure of the test hydraulic valve 12 gradually increases (such as 5MPa, 10MPa, 20MPa, 30MPa…), in the process, the pressure growth rate inside the pressure vessel 11 should be controlled to avoid the pressure difference between the pressure vessel 11 and the third pressure gauge 17 being too large. When the indication of the third pressure gauge 17 is equal to the expected simulated deep sea environment 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 test hydraulic valve 12 is realized, and the steady state performance test is completed. In addition, open the first stop valve 8, and adjust the second throttle valve 16 and the back pressure valve 18 to realize the reverse direction of oil flow. When testing the internal leakage, close the third stop valve 15, record the pressure difference change of the second pressure gauge 13 within a certain time, and calculate its internal leakage based on formula (1). After the test is completed, gradually depressurize the pressure vessel 11, while adjusting the back pressure valve 18, so that the indication of the third pressure gauge 17 is equal to the pressure in the cavity of the pressure vessel 11, in the process, the pressure drop rate inside the pressure vessel 11 should be controlled to avoid the pressure difference between the pressure vessel 11 and the third pressure gauge 17 being too large. When the system back pressure drops to the lower limit of the back pressure valve 18, open the fourth stop valve 19, and complete the pressure relief.

[0047] The present embodiment tests the deep sea steady state performance of the overflow valve:

[0048] The overflow valve as the test hydraulic valve 12 is connected to the test circuit, and the preparation before testing is done according to the present application, until the safety valve 6 and the back pressure valve 18 are adjusted so that the indication of the third pressure gauge 17 is equal to the pressure in the cavity of the pressure vessel 11 (both are the expected simulated deep sea environment pressure).

[0049] 1) Upper limit of pressure regulating range and pressure stability: continue to adjust the safety valve 6, adjust the safety valve 6 to 1.15 times the sum of the upper limit value of the test hydraulic valve 12 pressure regulating range and the expected simulated deep sea environment pressure, increase the speed of the hydraulic pump 4, gradually increase the flow through the test hydraulic valve 12 to the test flow, measure the upper limit value of the test hydraulic valve 12 pressure regulating range by the first pressure gauge 10, and record the pressure fluctuation value within 1 min and the pressure deviation value within 1 min.

[0050] 2) Internal leakage: Adjust the safety valve 6 to make the system pressure equal to the sum of 0.75 times the upper limit of the pressure regulating range of the test hydraulic valve 12 and the expected simulated deep sea environment pressure, close the third stop valve 15, and after 1 minute, the internal leakage of the test hydraulic valve 12 is indirectly measured by the change in the reading of the second pressure gauge 13. During the measurement of the internal leakage, the inlet pressure of the test hydraulic valve 12 is gradually decreased from the sum of 0.75 times the upper limit of the pressure regulating range and the expected simulated deep sea environment pressure to the lowest working pressure of the system, and several measurement points are set (the number of measurement points should be sufficient to draw a curve), the internal leakage of the test hydraulic valve 12 is measured at each point, and an inlet pressure-internal leakage characteristic curve is drawn, as shown in FIG. 2. Figure 2 .

[0051] 3) Steady state pressure-flow characteristic: Adjust the safety valve 6 to the sum of 1.15 times the upper limit of the pressure regulating range of the test hydraulic valve 12 and the expected simulated deep sea environment pressure, and make the flow through the test overflow valve 12 equal to the test flow, and the following tests are performed respectively:

[0052] ① Adjust the safety valve 6 to gradually decrease the system pressure, and when the reading of the high pressure flow meter 14 decreases to 1% of the test flow of the test hydraulic valve 12, the difference between the reading of the first pressure gauge 10 and the expected simulated deep sea environment pressure is the closing pressure of the test hydraulic valve 12;

[0053] ② Adjust the safety valve 6 to gradually increase the system pressure, and when the reading of the high pressure flow meter 14 increases from 0 to 1% of the test flow of the test hydraulic valve 12, the difference between the reading of the first pressure gauge 10 and the expected simulated deep sea environment pressure is the opening pressure of the test hydraulic valve 12; During the steady state pressure-flow characteristic test, the system pressure is changed, the inlet pressure of the test hydraulic valve 12 and the flow through the test hydraulic valve 12 at the corresponding pressure are measured at each point (the number of measurement points should be sufficient to draw a curve), and a steady state pressure-flow characteristic curve is drawn, as shown in FIG. 3. Figure 3 .

[0054] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for independently testing the deep-sea steady-state performance of a hydraulic valve, using a device for independently testing the deep-sea steady-state performance of a hydraulic valve, comprising an oil tank (1), a hydraulic pump (4), and a hydraulic valve under test (12); an oil inlet of the hydraulic pump (4) is connected to the oil tank (1) via a filter (2), a motor (3) is connected to the hydraulic pump (4) via a shaft coupling, and a one-way valve (5) is connected to an oil outlet of the hydraulic pump (4); a branch connected to an oil outlet of the one-way valve (5) is connected in sequence to a safety valve (6), a first throttle valve (7), and back to the oil tank (1); a main oil passage connected to the oil outlet of the one-way valve (5) is connected in sequence to a second stop valve (9), the hydraulic valve under test (12), a high-pressure flowmeter (14), a third stop valve (15), a second throttle valve (16), a back pressure valve (18), and a third throttle valve (20), and finally back to the oil tank (1); an oil inlet and an oil outlet of the hydraulic valve under test (12) are connected to a first pressure gauge (10) and a second pressure gauge (13), respectively; an oil outlet of the second throttle valve (16) is connected to a third pressure gauge (17); and the hydraulic valve under test (12) is located in a pressure vessel (11); the oil outlet of the one-way valve (5) is further connected to the oil outlet of the second throttle valve (16) via a first stop valve (8); the back pressure valve (18) is further connected in parallel to a fourth stop valve (19); characterized in that the method comprises the following processes: the first stop valve (8) and the fourth stop valve (19) are closed, the motor (3) is started, the rotating speed of the hydraulic pump (4) is set to the lowest working speed, the pressure vessel (11) is gradually pressurized, the safety valve (6) and the back pressure valve (18) are adjusted at the same time, the outlet pressure of the hydraulic valve under test (12) is gradually increased, and in this process, the pressure growth rate inside the pressure vessel (11) is controlled to avoid an excessively large pressure difference between the pressure vessel (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 adjustment of the back pressure valve (18) is stopped; the pressure and flow control of the hydraulic valve under test (12) is realized by adjusting the rotating speed of the motor (3), the set pressure of the safety valve (6), and the opening of the second throttle valve (16), 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 realize oil flow in the reverse direction; when the internal leakage test is performed, the third stop valve (15) is closed, the pressure difference change of the second pressure gauge (13) within a set time is recorded, and the internal leakage is calculated based on formula (1): wherein V0 is the oil pipe volume between the outlet of the hydraulic valve under test (12) and the third stop valve (15), Δp is the reading change value of the second pressure gauge (13), and K is the bulk modulus of the oil. At the end of the test, the pressure vessel (11) is gradually depressurized, while adjusting the back pressure valve (18) to make the reading of the third pressure gauge (17) equal to the pressure in the cavity of the pressure vessel (11), in the process, the rate of the internal pressure of the pressure vessel (11) should be controlled to avoid the pressure difference between the pressure vessel (11) and the third pressure gauge (17) being too large; when the back pressure of the system drops to the lower limit of the pressure regulating of the back pressure valve (18), the fourth stop valve (19) is opened to complete the depressurization.

2. The method for testing the steady-state performance of a hydraulic valve in deep sea according to claim 1, characterized in that, The pressure vessel (11) also includes a cavity that can only accommodate the test hydraulic valve (12).

3. The method of claim 2, wherein the hydraulic valve is a hydraulic valve for a deep-sea submersible vehicle. The internal pressure of the pressure vessel (11) is controlled by an independent pump source.

4. The method of claim 1, wherein the hydraulic valve is a hydraulic valve for a deep-sea submersible. A low-pressure flow meter (21) is also included, which is connected at the oil return port of the third throttle valve (20); in the case where the high-pressure flow meter (14) cannot be used, the actual flow is calculated using the low-pressure flow meter (21).

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