阅读说明：本技术 一种用于液压油多相流动特性研究的试验台 (Test bed for researching hydraulic oil multiphase flow characteristics ) 是由 胡建军 刘翔宇 李曼迪 孔德才 姚静 于 2020-07-10 设计创作，主要内容包括：本发明提供了一种用于液压油多相流动特性研究的试验台,包括：用于提供液压油的移动泵站,其包括固液混合油箱和清洁液压油箱；用于制备气体的气体发生装置；用于气液两相混合或气液固三相混合的多相混合装置；连接在主油路阀块与多相混合装置之间的工况切换阀块,工况切换阀块用于切换工作模式以分别进行气液两相、固液两相或气液固三相试验；用于接入油路中的试验装置；其中,在第一或第三状态下,清洁液压油箱与动力源连通,多相混合装置及气体发生装置接入油路中,从而进行气液两相流或气固液三相流试验；在第二状态下,固液混合油箱与动力源连通,并切断多相混合装置及气体发生装置与油路的连接,从而进行固液两相流试验。(The invention provides a test bed for researching the multiphase flow characteristics of hydraulic oil, which comprises: the mobile pump station is used for providing hydraulic oil and comprises a solid-liquid mixed oil tank and a clean hydraulic oil tank; a gas generating device for producing a gas; the multiphase mixing device is used for mixing gas phase and liquid phase or mixing gas phase, liquid phase and solid phase; the working condition switching valve block is connected between the main oil way valve block and the multiphase mixing device and used for switching working modes to respectively perform gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests; the test device is used for being connected into the oil way; in the first or third state, the clean hydraulic oil tank is communicated with the power source, and the multiphase mixing device and the gas generating device are connected into an oil way, so that a gas-liquid two-phase flow or gas-solid-liquid three-phase flow test is carried out; in the second state, the solid-liquid mixed oil tank is communicated with the power source, and the connection between the multiphase mixing device and the gas generating device and the oil way is cut off, so that a solid-liquid two-phase flow test is carried out.)

1. A test bench for research on hydraulic oil multiphase flow characteristics comprises:

the mobile pump station (10) is used for providing hydraulic oil and comprises a solid-liquid mixed oil tank (11) and a clean hydraulic oil tank (12), and the solid-liquid mixed oil tank is used for mixing the hydraulic oil with the solid-phase particles for the test;

a gas generating device (50) for producing gas;

the multiphase mixing device (60) is used for mixing gas and liquid phases or mixing gas, liquid and solid phases, and the gas generating device is connected with the multiphase mixing device;

the working condition switching valve block (70) is connected between the main oil way valve block and the multiphase mixing device and is used for switching working modes to respectively perform gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests;

a testing device (80) for accessing the oil circuit;

in a first state, the clean hydraulic oil tank is controlled to be communicated with the power source, and the multiphase mixing device and the gas generating device are connected into an oil way through the working condition switching valve block, so that a gas-liquid two-phase flow test is carried out;

in a second state, controlling the solid-liquid mixed oil tank to be communicated with the power source, and cutting off the connection of the multiphase mixing device and the gas generating device with an oil way through the working condition switching valve block so as to perform a solid-liquid two-phase flow test;

and in a third state, controlling the solid-liquid mixed oil tank to be communicated with the power source, and connecting the multiphase mixing device and the gas generating device into an oil way through the working condition switching valve block, so as to perform a gas-solid-liquid three-phase flow test.

2. The test stand of claim 1, wherein the mobile pump station further comprises:

the power source (20) is used for providing oil absorption power and is connected to oil outlets of the solid-liquid mixed oil tank and the clean hydraulic oil tank;

the main oil way valve block (30) is connected to the output end of the power source and is provided with a plurality of oil return pipe interfaces (81) communicated with the solid-liquid mixed oil tank and the clean hydraulic oil tank; and

and the bypass adjusting valve block (40) is used for adjusting the concentration of solid-phase particles and is connected between the main oil way valve block and the solid-liquid mixed oil tank.

3. The test bench according to claim 2, wherein the main oil way valve block comprises a first one-way valve (31), a first throttling speed regulating valve (32) and an overflow valve (33) connected to the inlet end of the first one-way valve, the overflow valve is communicated with the oil return pipe interface,

the inlet end of the first one-way valve is communicated with the output end of the power source, and the outlet end of the first throttling speed regulating valve is respectively communicated with the working condition switching valve block and the bypass regulating valve block.

4. The test bench according to claim 2, wherein the operating condition switching valve block comprises a second one-way valve (71) and a solid-liquid phase oil path led out from the inlet end of the second one-way valve, a first stop valve (72) is arranged at the outlet end of the second one-way valve, a second stop valve (73) is arranged in the solid-liquid phase oil path, the solid-liquid phase oil path is provided with a solid-liquid two-phase flow output interface (82) used for being connected with the inlet end of the test device,

opening the first stop valve, closing the second stop valve and connecting the multiphase mixing device and the gas generating device to perform a gas-liquid two-phase flow test or a gas-solid-liquid three-phase flow test,

the solid-liquid two-phase flow test is performed by closing the first shutoff valve and opening the second shutoff valve to shut off the multiphase mixer and the gas generator.

5. The test stand according to claim 2, characterized in that the by-pass regulating valve block comprises a main shut-off valve (41), a first secondary shut-off valve (42) and a second secondary shut-off valve (43) connected in parallel between the main shut-off valve and the solid-liquid mixed tank, and a plate filter (44) connected at the inlet end of the first secondary shut-off valve,

wherein the filtration precision of the plate filter is smaller than the diameter of the solid phase particles for test.

6. The test bench according to claim 1 or 2, characterized in that an oil suction switching valve block (13) is arranged at the oil outlets of the solid-liquid mixed oil tank and the clean hydraulic oil tank, and an oil return switching valve block (14) is arranged at the oil return ports of the solid-liquid mixed oil tank and the clean hydraulic oil tank.

7. The test bench according to claim 1 or 2, characterized in that a stirrer (111) is arranged between the oil suction port and the oil outlet of the solid-liquid mixed oil tank, the stirrer is arranged close to the oil return port, and a particle input port (112) and a first air filter (113) are respectively arranged at two sides close to the stirrer.

8. Test bench according to claim 1 or 2, characterized in that the clean hydraulic tank is provided with a second air filter (122), that an oil return filter (123) and a tube filter (124) are connected in series at the oil return port of the clean hydraulic tank, that a partition (121) is provided inside the clean hydraulic tank, that the oil intake port and the oil outlet port of the clean hydraulic tank are located at both sides of the partition,

wherein, the oil return filter is close to clean hydraulic tank, just the filter fineness of oil return filter be higher than with tubular filter's filter fineness.

9. The test bench of claim 1, wherein the gas generating device comprises a motor air pump assembly (51), a pneumatic triplet (52), a pneumatic reversing valve (53), a pneumatic throttle valve (54) and a gas flowmeter (55) which are connected in sequence, and the outlet end of the gas flowmeter is connected with the multiphase mixing device.

10. The test bench of claim 9, wherein the multi-phase mixing device comprises a cylindrical main body part (61), end caps (62) and bases (63) respectively connected to upper and lower ends of the main body part, a bubble sorting sheet (65) detachably installed between the end caps and the main body part, and a rotary impeller (64) installed on the base and extending into the main body part,

an oil inlet (611) and an air inlet (612) are arranged on the side wall of the main body part, an outlet (621) is arranged on the end cover, the oil inlet is connected with the outlet end of the working condition switching valve block, the air inlet is connected with the outlet end of the gas flowmeter, the outlet is connected with a multiphase flow oil way, and the multiphase flow oil way is provided with a multiphase flow output interface (83) used for being connected with the inlet end of the test device.

Technical Field

The invention belongs to the technical field of hydraulic pressure, and particularly relates to a test bed for researching the multiphase flow characteristics of hydraulic oil.

Background

Hydraulic oil is a working medium of many construction machines, and the quality of hydraulic oil has a great influence on the service life and safety of the construction machines. However, the hydraulic oil is often mixed with a small amount of gas or solid pollutants in the actual use process, and the existence of the gas or solid pollutants can pose certain threats to the hydraulic system, so that the normal operation of the hydraulic system is affected.

At present, most of related researches on mixing bubbles and particles with hydraulic oil are gas-liquid or solid-liquid two-phase flow CFD (computational fluid dynamics) simulation researches, corresponding test verification is relatively deficient, an existing test system is not perfect enough, and a test system specially aiming at simulation and test verification of three-phase flow is not provided.

In addition, in the existing two-phase flow test method, gas is directly introduced into the liquid container, and the volume fraction of bubbles mixed in the liquid is controlled by controlling the volume of the liquid and the input flow rate of the gas, so that the flow characteristics of the gas-liquid two-phase fluid in different structures are observed, the control of the volume fraction of the bubbles is inconvenient, and the reliability of the test result is poor.

Disclosure of Invention

In view of the above technical problems, the present invention is directed to a test bed for research on multiphase flow characteristics of hydraulic oil, which is capable of performing a gas-liquid two-phase or solid-liquid two-phase or gas-liquid-solid three-phase fluid test, controlling solid-phase particle concentration and/or bubble volume fraction, facilitating the research on multiphase flow characteristics of hydraulic oil, and enhancing reliability of test results.

To this end, according to the present invention, there is provided a test bench for research on multiphase flow characteristics of hydraulic oil, comprising: the mobile pump station is used for providing hydraulic oil and comprises a solid-liquid mixed oil tank and a clean hydraulic oil tank, and the solid-liquid mixed oil tank is used for mixing the hydraulic oil with the solid-phase particles for the test; a gas generating device for producing a gas; the gas generating device is connected with the multiphase mixing device; the working condition switching valve block is connected between the main oil way valve block and the multiphase mixing device and used for switching working modes to respectively perform gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests; the test device is used for being connected into the oil way; in a first state, the clean hydraulic oil tank is controlled to be communicated with the power source, and the multiphase mixing device and the gas generating device are connected into an oil way through the working condition switching valve block, so that a gas-liquid two-phase flow test is carried out; in a second state, controlling the solid-liquid mixed oil tank to be communicated with the power source, and cutting off the connection between the multiphase mixing device and the gas generating device and an oil way through the working condition switching valve block, so as to perform a solid-liquid two-phase flow test; and in a third state, controlling the solid-liquid mixed oil tank to be communicated with the power source, and connecting the multiphase mixing device and the gas generating device into an oil way through the working condition switching valve block, so as to perform a gas-solid-liquid three-phase flow test.

In one embodiment, the mobile pump station further comprises: the power source is used for providing oil absorption power and is connected with oil outlets of the solid-liquid mixed oil tank and the clean hydraulic oil tank; the main oil way valve block is connected to the output end of the power source and provided with a plurality of oil return pipe interfaces communicated with the solid-liquid mixed oil tank and the clean hydraulic oil tank; and the bypass adjusting valve block is used for adjusting the concentration of solid-phase particles and is connected between the main oil way valve block and the solid-liquid mixed oil tank.

In one embodiment, the main oil line valve block includes a first check valve, a first throttling speed regulating valve and an overflow valve connected to an inlet end of the first check valve, the overflow valve is communicated with the oil return pipe connector, an inlet end of the first check valve is communicated with an output end of the power source, and an outlet end of the first throttling speed regulating valve is communicated with the working condition switching valve block and the bypass regulating valve block respectively.

In one embodiment, the operating condition switching valve block includes a second check valve and a solid-liquid phase oil path led out from an inlet end of the second check valve, a first stop valve is arranged at an outlet end of the second check valve, a second stop valve is arranged in the solid-liquid phase oil path, the solid-liquid phase oil path is provided with a solid-liquid two-phase flow output interface for connecting with an inlet end of the testing device, the first stop valve is opened, the second stop valve is closed to connect the multiphase mixing device and the gas generating device, so that a gas-liquid two-phase flow test or a gas-solid-liquid three-phase flow test is performed, the first stop valve is closed, and the second stop valve is opened to disconnect the multiphase mixing device and the gas generating device, so that a solid-liquid two-phase flow test is performed.

In one embodiment, the bypass regulating valve block comprises a main shutoff valve, a first auxiliary shutoff valve and a second auxiliary shutoff valve which are connected in parallel between the main shutoff valve and the solid-liquid mixed oil tank, and a plate filter connected at an inlet end of the first auxiliary shutoff valve, wherein the plate filter has a filtering accuracy smaller than the diameter of solid-phase particles for test.

In one embodiment, oil suction switching valve blocks are arranged at oil outlets of the solid-liquid mixed oil tank and the clean hydraulic oil tank, and oil return switching valve blocks are arranged at oil return ports of the solid-liquid mixed oil tank and the clean hydraulic oil tank.

In one embodiment, a stirrer is arranged between an oil suction port and an oil outlet of the solid-liquid mixed oil tank, the stirrer is arranged close to the oil return port, and a particle feeding port and a first air filter are respectively arranged on two sides close to the stirrer.

In one embodiment, the clean hydraulic oil tank is provided with a second air filter, an oil return filter and a tubular filter are connected in series at an oil return port of the clean hydraulic oil tank, a partition plate is arranged inside the clean hydraulic oil tank, an oil suction port and an oil outlet of the clean hydraulic oil tank are located on two sides of the partition plate, the oil return filter is close to the clean hydraulic oil tank, and the filtering accuracy of the oil return filter is higher than that of the tubular filter.

In one embodiment, the gas generating device comprises a motor air pump assembly, a pneumatic triplet, a pneumatic reversing valve, a pneumatic throttle valve and a gas flowmeter which are connected in sequence, and the outlet end of the gas flowmeter is connected with the multiphase mixing device.

In one embodiment, the multiphase mixing device comprises a cylindrical main body part, end covers and a base which are respectively connected to the upper end and the lower end of the main body part, a removable bubble sorting sheet which is installed between the end covers and the main body part, and a rotary impeller which is installed on the base and extends into the main body part, wherein an oil inlet and an air inlet are formed in the side wall of the main body part, an outlet is formed in the end cover, the oil inlet is connected with the outlet end of the working condition switching valve block, the air inlet is connected with the outlet end of the gas flowmeter, the outlet is connected with a multiphase flow oil path, and the multiphase flow oil path is provided with a multiphase flow output interface which is connected with the inlet end of the test device.

Compared with the prior art, the method has the advantages that:

the test bed for researching the multiphase flow characteristics of the hydraulic oil can perform gas-liquid two-phase or solid-liquid two-phase or gas-liquid-solid three-phase fluid tests, and can control the solid-phase particle concentration and/or the bubble volume fraction in the test process, so that the reliability of the test result is obviously enhanced. The test bed can effectively improve the solid-phase particle concentration and the volume fraction of bubbles in oil through the bypass adjusting valve block and the multiphase mixing device, is simple and convenient to control, is favorable for enhancing the accuracy of test data, and is very favorable for the research of the multiphase flow characteristics of hydraulic oil. In addition, the test bed can rapidly switch different working modes, so that gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests are respectively carried out, and the test efficiency is greatly improved.

Drawings

The invention will now be described with reference to the accompanying drawings.

Fig. 1 is a structural distribution diagram of a test bench for research on multiphase flow characteristics of hydraulic oil according to the present invention.

Fig. 2 is a schematic diagram of a main oil line valve block in the test stand for the study of the multiphase flow characteristics of hydraulic oil according to the present invention shown in fig. 1.

Fig. 3 is a schematic diagram of a bypass regulating valve block in the test stand for the study of the multiphase flow characteristics of hydraulic oil according to the present invention shown in fig. 1.

Fig. 4 is a schematic diagram of the operating condition switching valve block in the test stand for the study of the multiphase flow characteristics of hydraulic oil according to the present invention shown in fig. 1.

Fig. 5 is an exploded view of a multiphase mixing device in a test stand for research on multiphase flow characteristics of hydraulic oil according to the present invention.

Fig. 6 is a plan view of a multiphase mixing device in a test stand for research on multiphase flow characteristics of hydraulic oil according to the present invention.

FIG. 7 is a schematic diagram of a gas-liquid two-phase flow test performed by the test bench for the study of the multiphase flow characteristics of hydraulic oil according to the present invention.

FIG. 8 is a schematic diagram of a solid-liquid two-phase flow test carried out by the test bench for the study of the multiphase flow characteristics of hydraulic oil according to the present invention.

FIG. 9 is a schematic diagram of a gas-liquid-solid three-phase flow test carried out by the test bench for the research on the multiphase flow characteristics of hydraulic oil according to the invention.

In the present application, the drawings are all schematic and are used only for illustrating the principles of the invention and are not drawn to scale. In the drawings, like components are designated by like reference numerals.

Detailed Description

The invention is described below with reference to the accompanying drawings.

Fig. 1 is a structural distribution diagram of a test stand 100 for a hydraulic oil multiphase flow characteristic study according to the present invention. As shown in fig. 1, the test stand 100 includes a mobile pump station 10, and the mobile pump station 10 is used for supplying hydraulic oil. The mobile pump station 10 comprises a solid-liquid mixed oil tank 11 and a clean hydraulic oil tank 12, wherein the solid-liquid mixed oil tank 11 is used for mixing hydraulic oil with solid-phase particles for testing, and the clean hydraulic oil tank 12 is used for storing clean and pollution-free hydraulic oil for gas-liquid two-phase flow testing. The test bed 100 for the research of the hydraulic oil multiphase flow characteristics can perform gas-liquid two-phase flow or solid-liquid two-phase flow or gas-liquid-solid three-phase flow tests. The gas-liquid two-phase flow refers to that hydraulic oil contains constant-diameter bubbles with a certain volume fraction, the solid-liquid two-phase flow refers to that hydraulic oil contains solid particles with a certain concentration, and the gas-liquid-solid three-phase flow refers to that hydraulic oil contains a certain amount of gas and solid particles with a certain concentration.

As shown in fig. 1, the solid-liquid mixed oil tank 11 includes a stirrer 111. The stirrer 111 is arranged between the oil suction port and the oil outlet of the solid-liquid mixed oil tank 11, and the stirrer 111 is close to the oil return port. The agitator 111 is preferably an electric agitator. A particle inlet 112 and a first air filter 113 are provided on both sides of the mixer 111, respectively, and solid-phase particles for a test can be introduced into the solid-liquid mixed oil tank 11 through the particle inlet 112. The stirrer 111 is used for stirring and mixing the solid-phase particles for testing, and the particle-charging port 112 may be provided near the stirrer 111 in order to sufficiently mix the solid-phase particles for testing with the hydraulic oil in the solid-liquid mixing tank 11. In one embodiment, the solid-liquid mixed oil tank 11 has a capacity of 150L. In addition, a level liquid thermometer is also arranged in the solid-liquid mixed oil tank 11 and used for displaying the level height and the temperature of the oil liquid in the solid-liquid mixed oil tank 11.

As shown in fig. 1, a partition plate 121 is provided inside the clean hydraulic oil tank 12. The partition plate 121 is fixed at the bottom of the solid-liquid mixed oil tank 11, and an oil suction port and an oil outlet of the clean hydraulic oil tank 12 are positioned at both sides of the partition plate 121. This enables the oil return area and the oil suction area to be separated, thereby ensuring a substantial cleaning capability for cleaning the hydraulic oil tank 12. The clean hydraulic tank 12 is also provided with a second air filter 122. An oil return filter 123 and a tubular filter 124 are connected in series at an oil return port of the clean hydraulic oil tank 122, the oil return filter 123 is close to the clean hydraulic oil tank 12, and the filtering precision of the oil return filter 123 is higher than that of the tubular filter 124. In one embodiment, the clean hydraulic reservoir 12 has a capacity of 150L. Likewise, a liquid level thermometer is also provided in the clean hydraulic tank 12, and is used for displaying the liquid level height and the temperature of the oil in the clean hydraulic tank 12.

According to the invention, oil suction switching valve blocks 13 are arranged at oil outlets of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12, and oil return switching valve blocks 14 are arranged at oil return ports of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12. As shown in fig. 1, the oil suction switching valve block 13 includes two stop valves, the inlet ends of the two stop valves are respectively connected to the oil outlets of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12, and the outlet ends of the two stop valves are communicated and serve as the outlet end of the oil suction switching valve block 13. In the test, when the supply of the oil to the solid-liquid mixed oil tank 11 is required, the shutoff valve communicating with the solid-liquid mixed oil tank 11 is opened, and the shutoff valve communicating with the clean hydraulic oil tank 12 is closed. Conversely, when the clean hydraulic tank 12 is required for oil supply, the shutoff valve communicating with the clean hydraulic tank 12 is opened, and the shutoff valve communicating with the solid-liquid mixture tank 11 is closed. Thus, the oil feed liquid can be switched between the solid-liquid mixture tank 11 and the clean hydraulic tank 12 by the oil suction switching valve block 13. This can effectively improve the liquid supply switching efficiency and control accuracy of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12.

Similarly, the oil return switching valve block 14 includes two stop valves, the inlet ends of the two stop valves are communicated with the oil return pipeline and are respectively connected with the oil outlets of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12, and the outlet ends of the two stop valves are respectively communicated with the oil return ports of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12. During the test, when oil is returned through the solid-liquid mixed oil tank 11, the shutoff valve communicating with the solid-liquid mixed oil tank 11 is opened, and the shutoff valve communicating with the clean hydraulic oil tank 12 is closed. Conversely, when returning oil through the clean hydraulic oil tank 12, the shutoff valve communicating with the clean hydraulic oil tank 12 is opened, and the shutoff valve communicating with the solid-liquid mixed oil tank 11 is closed. Thus, the return oil can be switched between the solid-liquid mixture tank 11 and the clean hydraulic tank 12 by the return oil switching valve block 13. This can effectively improve the oil return switching efficiency and the control accuracy of the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12.

According to the present invention, a power source 20 is connected to the outlet end of the oil suction switching valve block 13, and the power source 20 is used for providing oil suction power. The power source 20 includes the motor and the gear pump of being connected with the motor, and the gear pump has stronger antipollution ability in comparison with other hydraulic pumps, and it can satisfy the circulation that contains granule fluid.

As shown in fig. 1, a main oil path valve block 30 is connected to an output end of the power source 20, and the main oil path valve block 30 is used to integrally mount a plurality of regulator valves. Fig. 2 is a schematic diagram of the main oil passage valve block 30. As shown in fig. 2, the main oil valve block 30 includes a first check valve 31 and a first throttle speed valve 32 connected in sequence, and an inlet end of the first check valve 31 communicates with an output end of the power source 20. In order to ensure the safety of the oil supply system of the test bed 100, a relief valve 33 is arranged at the inlet end of the first check valve 31, and the outlet end of the relief valve 33 is communicated with an oil return pipeline. In the process of supplying oil, the first throttling speed regulating valve 32 is regulated to enable the oil supply flow to reach the preset flow requirement of the test. A flow meter 15 is arranged at the output end of the power source 20, and the flow meter 15 can observe the regulated oil supply flow of the first throttling speed regulating valve 32 in real time. Furthermore, a particle concentration monitoring point 16 is connected to the outlet end of the first throttle valve 32, and the particle concentration monitoring point 16 can display the concentration of particles in the oil supplied in the test.

As shown in fig. 2, the main oil valve block 30 further includes a plurality of oil return pipe interfaces 81, and the plurality of oil return pipe interfaces 81 communicate with the solid-liquid mixed oil tank 11 and the clean hydraulic oil tank 12 through oil return lines. The number of the oil return pipe connections 81 is preferably 3. Therefore, the plurality of oil return pipe interfaces 81 are communicated with the outlet end of the overflow valve 33 and then communicated with the inlet end of the oil return switching valve block 14 through oil return pipes. A plurality of oil return pipe interfaces 81 are used to connect the oil outlets of the test apparatus 80 (described below) to return the tested fluid to the solid-liquid mixed oil tank 11 or the clean hydraulic oil tank 12. In order to ensure that the required test data can be obtained in real time, the plurality of oil return pipe interfaces 81 are respectively and correspondingly provided with particle concentration monitoring points 16. A plurality of particle concentration monitoring points 16 are correspondingly connected in each oil return pipe interface 81 through a stop valve. During the test, open the granule concentration monitoring point 16 that corresponds in the oil return pipe interface 81 who is connected with testing arrangement 80, can obtain the solid phase particulate matter concentration in the oil return fluid in real time. In the actual test process, the number of the oil return pipe interfaces 81 connected to the main oil valve block 30 is selected according to the requirements of the test apparatus 80.

According to the present invention, a bypass adjustment valve block 40 is provided between the main oil passage valve block 30 and the solid-liquid mixed oil tank 11. The bypass adjusting valve block 40 is connected in the main oil way in parallel, and the bypass adjusting valve block 40 is used for adjusting the concentration of solid-phase particles of oil provided by the solid-liquid mixed oil tank 11. As shown in fig. 3, the bypass adjustment valve block 40 includes a main shutoff valve 41, a first sub-shutoff valve 42 and a second sub-shutoff valve 43 connected in parallel between the main shutoff valve 41 and the solid-liquid mixed fuel tank 11, and a plate filter 44 connected to an inlet end of the first sub-shutoff valve 42. The outlet end of the plate filter 44 serves as the outlet end of the bypass regulator valve block 40 and communicates with the solid-liquid mixed oil tank 11. The plate filter 44 has a filtering accuracy smaller than the diameter of the solid-phase particles for test.

In the test stand 100, during the solid-liquid two-phase flow test, the bypass regulator valve block 40 operates, and the main shutoff valve 41 is in an open state. When the particle concentration monitoring point 16 connected to the outlet end of the first throttle valve 32 detects that the particle concentration is greater than the preset value, the first secondary shut-off valve 42 is opened, and the second secondary shut-off valve 43 is closed, so that the oil is filtered by the plate filter 44 to reduce the particle content in the oil. Until the particulate matter concentration is monitored at the particulate matter concentration monitoring point 16 to reach the test preset value, the first secondary shut-off valve 42 is closed and the second secondary shut-off valve 43 is opened for a period of time. When the particle concentration monitoring point 16 monitors that the particle concentration is less than the preset test value, the second auxiliary shutoff valve 43 is opened, the first auxiliary shutoff valve 42 is closed, and meanwhile, solid-phase particles are put into the solid-liquid mixed oil tank 11 through the particle putting port 112, so that the particle concentration in the oil liquid is increased until the particle concentration reaches the preset test value. In the test process, the operation is repeated to adjust the particulate matter concentration, so that the adjustment of the particulate matter concentration of the oil liquid provided by the solid-liquid mixed oil tank 11 is completed.

As shown in fig. 1, an outlet end of the main oil passage valve block 30 is connected to a working condition switching valve block 70, and the working condition switching valve block 70 is used for switching a working state to perform a gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase test. Fig. 4 is a schematic diagram of the condition switching valve block 70. As shown in fig. 4, the operating condition switching valve block 70 includes a second check valve 71 and a solid-liquid phase oil passage led out from an inlet end of the second check valve 71. A first stop valve 72 is arranged at the outlet end of the second check valve 71, a second stop valve 73 is arranged in the solid-liquid phase oil path, and the solid-liquid phase oil path is provided with a solid-liquid two-phase flow output interface 82 for connecting with the inlet end of the test device 80. A throttle speed control valve 74 is connected to an outlet end of the second cut-off valve 73 to control the flow rate of the oil. In the test process, the first cut-off valve 72 is opened, the second cut-off valve 73 is closed, and the multiphase mixing device 60 and the gas generating device 50 (described below) are connected, so that a gas-liquid two-phase flow test or a gas-solid-liquid three-phase flow test is performed. The solid-liquid two-phase flow test was performed by closing the first shutoff valve 72 and opening the second shutoff valve 73 to shut off the multiphase mixer 60 and the gas generator 50.

In this embodiment, the solid-liquid phase oil path includes a first solid-liquid phase branch and a second solid-liquid phase branch, an inlet end of the first solid-liquid phase branch is connected between the second stop valve 73 and the throttle speed regulating valve 74, and the second solid-liquid phase branch is connected at an outlet end of the throttle speed regulating valve 74. The first solid-liquid phase branch and the second solid-liquid phase branch are both provided with a flowmeter 15 and an overflow valve, and the end parts of the flowmeters are respectively provided with a solid-liquid two-phase flow output interface 82. In the test process, the inlet end of the test device can be selectively connected with one solid-liquid two-phase flow output interface 82 for testing, and the oil flow in the branch is displayed through the corresponding flow meter 15. When the first solid-liquid phase branch is connected, the oil flow does not need to be adjusted, and when the second solid-liquid phase branch is connected, the oil flow can be further adjusted through the throttling speed regulating valve 74.

The test stand 100 also includes a gas generating device 50 for producing gas in accordance with the present invention. As shown in fig. 1, the gas generating device 50 includes a motor air pump assembly 51, a pneumatic triplet 52, a pneumatic reversing valve 53, a pneumatic throttle valve 54 and a gas flow meter 55, which are connected in sequence, and an outlet end of the gas flow meter 55 is used as an outlet of the gas generating device 50 and is connected with a multiphase mixing device 60 (described below). When a gas-liquid two-phase or gas-liquid-solid three-phase flow test is performed, the gas generating device 50 is connected, gas is produced through the gas generating device 50, and the gas flow is observed in real time through the gas flowmeter 55.

According to the invention, the test stand 100 further comprises a multiphase mixing device 60, the multiphase mixing device 60 being used for gas-liquid two-phase mixing or gas-liquid-solid three-phase mixing. As shown in fig. 5 and 6, the multiphase mixing device 60 includes a cylindrical main body portion 61. An end cover 62 is provided at the upper end of the main body portion 61, and an air bubble sorting sheet 65 is provided between the end cover 62 and the main body portion 61, and the air bubble sorting sheet 65 can be replaced. The bubble sorting sheet 65 is provided with a plurality of small holes, the bubble sorting sheet 65 is provided with different specifications and sizes, and the diameters of the small holes on the different bubble sorting sheets 65 are different. In the test, the bubble sorting sheet 65 with the corresponding specification is selected according to the actual requirement, so that bubbles with the corresponding diameter are generated. A base 63 for fixing the multiphase mixing device 60 is provided at the lower both ends of the main body portion 61, a rotary impeller 64 is provided on the base 63, the rotary impeller 64 axially extends into the main body portion 61, and the rotary impeller 64 is used to accelerate the mixing of the fluid inside the multiphase mixing device 60. It should be noted that directional terms or qualifiers "up", "down", etc. used in the present application are all with reference to fig. 5. They are not intended to limit the absolute positions of the parts involved, but may vary from case to case.

As shown in fig. 5 and 6, an oil inlet 611 and an air inlet 612 are provided on the side wall of the main body portion 61, and an outlet 621 is provided on the end cover 62. The oil inlet 611 and the air inlet 612 are provided at the same axial position of the main body portion 61, and are arranged offset in the circumferential direction. The axial directions of the oil inlet 611 and the air inlet 612 are parallel and are aligned with the blades of the rotating impeller 64, respectively. Therefore, when oil and gas are introduced through the oil inlet 611 and the gas inlet 612, a tangential force can be generated on the rotary impeller 64. The oil inlet 611 is connected with the outlet end of the operating condition switching valve block 70, and a flow meter 15 is arranged between the multiphase mixing device 60 and the operating condition switching valve block 70, and the flow rate of the liquid phase fluid introduced into the multiphase mixing device 60 can be observed in real time through the flow meter 15. The gas inlet 612 is connected to the outlet end of the gas flow meter 55 in the gas generating apparatus 50. Accordingly, the oil is supplied from the oil inlet 611 to the multiphase mixing device 60, and the gas is supplied from the gas inlet 612 to the multiphase mixing device 60, and when the oil is supplied and the gas is supplied, an impact force is generated to the rotary impeller 64, so that the rotary impeller 64 is rotated, thereby accelerating the mixing of the multiphase fluid. The gas-liquid two-phase mixed fluid or the gas-liquid-solid three-phase fluid formed by the multiphase mixing device 60 is discharged from the outlet 621. In the present embodiment, the volume fraction of the gas in the multiphase flow formed by the multiphase mixing device 60 is calculated and controlled by the ratio of the gas flow input from the gas inlet 612 to the liquid flow input from the oil inlet 611 of the multiphase mixing device 60.

In the present embodiment, the multiphase mixing device 60 is made of a transparent material, so that the mixing condition of the multiphase fluid inside the multiphase mixing device 60 can be observed in real time. Preferably, the multiphase mixing device 60 is made of acrylic sheet.

According to the present invention, the outlet 621 of the multiphase mixing device 60 is connected to a multiphase oil path provided with a multiphase flow output port 83 for connection with the inlet end of the test device 80. The multiphase oil circuit comprises a first gas-liquid-solid phase branch and a second gas-liquid-solid phase branch, wherein a flowmeter 15 and an overflow valve are arranged in the first gas-liquid-solid phase branch and the second gas-liquid-solid phase branch, and the end parts of the flowmeters are respectively provided with a multiphase flow output interface 83. A throttle speed regulating valve 90 is also arranged in the first gas-liquid-solid phase branch. During the test, the inlet end of the test device 80 can select one of the multiphase flow output ports 83 to be connected for testing, and the flow rate of the oil in the branch is displayed through the corresponding flow meter 15. When the first gas-liquid-solid phase branch is connected, the flow of oil and liquid can be further regulated through the throttling speed regulating valve. When the second gas-liquid-solid phase branch is connected, the flow of oil liquid does not need to be adjusted. Further, a particle concentration monitoring point 16 is connected to the inlet ends of the first gas-liquid-solid phase branch and the second gas-liquid-solid phase branch through a shutoff valve 91. During the test, the solid-phase particulate matter concentration in the return oil can be obtained in real time through the particle concentration monitoring point 16.

According to the present invention, the test stand 100 further includes a particle concentration detector (not shown), and each particle concentration monitoring point 16 provided in the oil passage system is connected to the particle concentration detector as a sampling point. Thus, sampling is performed through each particle concentration monitoring point 16, and the concentration of solid phase particles in the liquid in each area in the oil path system is detected through the particle concentration detector.

The test bed 100 for the research of the hydraulic oil multiphase flow characteristics can switch different working modes through the working condition switching valve block 70 so as to respectively perform gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests. The operation of the test stand 100 will be described below according to different operation modes.

When a gas-liquid two-phase flow test is carried out through the test bed 100, the clean hydraulic oil tank 12 is connected into an oil way system through the oil suction switching valve block 13, and the oil return pipeline is communicated with an oil return port of the clean hydraulic oil tank 12 through the oil return switching valve block 14. Meanwhile, the first cut-off valve 72 of the condition switching valve block 70 is opened, and the second cut-off valve 73 is closed to connect the multiphase mixing device 60 and the gas generating device 50 into the oil passage system, thereby performing a gas-liquid two-phase flow test. At this time, the test stand 100 is in the first state. Fig. 7 is a schematic diagram of the gas-liquid two-phase flow test performed by the test stand 100.

In the process of carrying out the gas-liquid two-phase flow test, firstly, the oil inlet of the test device 80 is connected with one multiphase flow output interface 83 in the multiphase oil path, and the oil return port of the test device 80 is connected with one oil return pipe interface 81 in the main oil path valve block 30. Thereafter, the bubble separation plate 65 in the multiphase mixing device 60 is selected according to the gas bubble diameter requirement in the test, and the opening pressure of the relief valve 33 in the main oil passage valve block 30 is adjusted to the test requirement value. Then, the power source 20 is started, and the first throttle valve 32 is adjusted so that the flow rate of the oil circuit system becomes a preset test value. Meanwhile, the flow meter 15 connected to the output end of the power source 20 is used for real-time observation until the flow of the oil-way system meets the test requirement, and the oil sucked from the clean hydraulic oil tank 12 in the oil-way system is input into the multiphase mixing device 60. Meanwhile, a motor air pump assembly 51 in the gas generating device 50 is opened, the pneumatic triple piece 52, the pneumatic reversing valve 53 and the pneumatic throttle valve 54 are adjusted to generate gas, and the gas flow is observed in real time through the gas flowmeter 55 until the output gas flow is a value required by a test. The gas generated by the gas generator 50 and the oil in the oil line system are simultaneously input into the multiphase mixing device 60 for gas-liquid two-phase mixing, and the mixed gas and oil are output from the outlet 621 to form bubble-containing oil with a certain concentration required by the test, and the bubble-containing oil enters the test device 80 for gas-liquid two-phase flow test. After the test, the fluid flows through the return line connection 81 of the main circuit valve 30 into the return line and then back into the clean hydraulic tank 12. Thereby, the gas-liquid two-phase flow test was completed.

In the present embodiment, the bubble volume fraction control method is calculated and controlled by the ratio of the gas flow input through the gas inlet 612 to the liquid flow input through the oil inlet 611 of the multiphase mixing device 60. The ratio of the gas flow to the liquid flow is the volume fraction of the gas in the mixed fluid.

When a solid-liquid two-phase flow test is carried out through the test bed 100, the solid-liquid mixed oil tank 11 is connected into an oil path system through the oil suction switching valve block 13, and the oil return pipeline is communicated with an oil return opening of the solid-liquid mixed oil tank 11 through the oil return switching valve block 14. At the same time, the second cut-off valve 73 of the condition switching valve block 70 is opened, and the first cut-off valve 72 is closed to cut off the multiphase mixer 60 and the gas generator 50, thereby performing a solid-liquid two-phase flow test. At this time, the test stand 100 is in the second state. Fig. 8 is a schematic diagram of a solid-liquid two-phase flow test performed by the test stand 100.

In the process of performing the solid-liquid two-phase flow test, firstly, the oil inlet of the test device 80 is connected with one solid-liquid two-phase flow output interface 82 in the solid-liquid phase oil path, and the oil return port of the test device 80 is connected with one oil return pipe interface 81 in the main oil path valve block 30. Then, the test particles are put into the solid-liquid mixed oil tank 11 through the particle putting port 112, and the stirrer 111 is started to stir for a period of time, so that the particles and the oil are sufficiently mixed. After the stirring and mixing are finished, the opening pressure of the relief valve 33 in the main oil passage valve block 30 is adjusted to a predetermined value for the test. Then, the second cut-off valve 73 is closed, the main cut-off valve 41 is opened, the power source 20 is started, and the first throttle speed valve 32 is adjusted until the value of the flow meter 15 connected to the output side of the power source 20 is a test flow rate. In the process, the concentration of the solid-phase particles in the solid-liquid two-phase fluid in the oil way system is adjusted through the bypass adjusting valve 40 until the concentration of the particles meets the test requirement. Then, the second stop valve 73 is opened, the main throttle valve 41 is closed, the flow rate in the corresponding oil path is displayed in real time through the flow meter 15 in the first solid-liquid phase branch or the second solid-liquid phase branch in the solid-liquid phase oil path, and when the second solid-liquid phase branch is connected, the flow rate of the oil liquid can be further adjusted through the throttle speed regulating valve 74. The solid-liquid two-phase fluid in the oil circuit system enters a test device 80 to carry out a solid-liquid two-phase flow test. After the test, the fluid flows into the oil return line through the oil return pipe connector 81 of the main oil path valve 30, and then flows back into the solid-liquid mixed oil tank 11. Thus, the solid-liquid two-phase flow test was completed.

When a gas-liquid-solid three-phase flow test is carried out through the test bed 100, the solid-liquid mixed oil tank 11 is connected into an oil path system through the oil suction switching valve block 13, and an oil return pipeline is communicated with an oil return port of the solid-liquid mixed oil tank 11 through the oil return switching valve block 14. At this time, the test stand 100 is in the third state. FIG. 9 is a schematic diagram of a gas-liquid-solid three phase flow test conducted by test stand 100. The gas-liquid-solid three-phase flow test process is combined with the gas-liquid two-phase flow test and the solid-liquid two-phase flow test.

In the process of gas-liquid-solid three-phase flow test, firstly, an oil inlet of the test device 80 is connected with a solid-liquid two-phase flow output interface 82 in a solid-liquid phase oil way, and an oil return port of the test device 80 is connected with an oil return pipe interface 81 in the main oil way valve block 30. Then, the particles for the test are put into the solid-liquid mixed oil tank 11 through the particle putting port 112 and mixed to form a solid-liquid two-phase mixed fluid, specifically referring to the process in the solid-liquid two-phase flow test, and the solid-liquid two-phase mixed fluid in the oil line system is further introduced into the multiphase mixing device 60 through the oil inlet 611. Thereafter, the gas generating device 50 is turned on to prepare the gas, and the generated gas is introduced into the multiphase mixing device 60 through the gas inlet 612. The gas and solid-liquid two-phase mixed fluid are mixed in the multiphase mixing device 60 to form a three-phase mixed fluid, and the three-phase mixed fluid is output from the outlet 621. The three-phase mixed fluid output by the multiphase mixing device 60 enters a testing device 80 to carry out a gas-liquid-solid three-phase flow test. After the test, the fluid flows into the oil return line through the oil return pipe connector 81 of the main oil path valve 30, and then flows back into the solid-liquid mixed oil tank 11. Thus, a gas-liquid-solid three-phase flow test was completed.

According to the present invention, since the test stand 100 is involved in the testing of particulate matter and air bubbles, the test stand 100 needs to be cleaned after each test is completed. Specifically, the pipeline of the test stand 100 is flushed. According to the test stand 100 of the present invention, the hydraulic oil in the clean hydraulic oil tank 12 can be used to flush the lines. The test bed is provided with a plurality of hoses, an oil outlet and an oil return port of the oil circuit system can be connected through the hoses during cleaning, and the oil circuit system is sequentially washed until the concentration of particles in oil is the same as that before the test.

The test bed 100 for the research of the hydraulic oil multiphase flow characteristics can perform a gas-liquid two-phase or solid-liquid two-phase or gas-liquid-solid three-phase fluid test, and can control the solid-phase particle concentration and/or the bubble volume fraction in the test process, so that the reliability of the test result is obviously enhanced. The test bed 100 can effectively improve the solid-phase particle concentration and the volume fraction of bubbles in oil through the bypass adjusting valve block 40 and the multiphase mixing device 60, is simple and convenient to control, is beneficial to enhancing the accuracy of test data, and is very beneficial to the research of the multiphase flow characteristics of hydraulic oil. In addition, the test bed 100 can rapidly switch different working modes, so that gas-liquid two-phase, solid-liquid two-phase or gas-liquid-solid three-phase tests are respectively performed, and the test efficiency is greatly improved.

Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and do not limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing examples, or that equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.