Flow and flow resistance testing device for flammable and explosive media

Abstract

The utility model provides a flow and flow resistance testing device for flammable and explosive media. The device comprises a liquid storage tank used for storing a medium; the anti-explosion gear pump set is connected to the liquid storage tank in series and used for conveying a medium and providing pressure needed by medium circulation; the self-standing pressure reducing valve is arranged at the downstream of the anti-explosion gear pump set, is connected between the anti-explosion gear pump set and the liquid storage tank in series and is used for reducing the pressure of the medium to enable the medium to be output in a stable flow manner; the electric flow regulating valve is connected in series between the self-standing pressure reducing valve and the liquid storage tank and is used for regulating the flow of the medium; the mass flow meter is connected in series between the electric flow regulating valve and the liquid storage tank and is used for monitoring the medium flow; a tested experiment piece is connected between the electric flow regulating valve and the mass flow meter in series, and the two ends of the tested experiment piece are connected with a differential pressure transmitter in parallel, and the differential pressure transmitter is used for measuring the differential pressure of a medium flowing through the tested experiment piece. According to the invention, accurate adjustment of the medium flow is realized, and the accuracy of measured data is ensured.

Description

Technical Field

[0001] The present disclosure relates to the technical field of flow rate and flow resistance testing of media, and in particular to a flow rate and flow resistance testing device for flammable and explosive media. Background Art

[0002] The flow resistance test device is designed mainly to evaluate the flow resistance characteristics of the helicopter fuel system supply and oil delivery hoses under a certain flow rate. Flow resistance is an important process parameter and technical indicator of the flow-through workpiece. During the development, research and product testing process, a large amount of pressure resistance, flow characteristics and resistance characteristics test data are required.

[0003] At present, conventional flow and flow resistance test devices cannot accurately control the flow of the workpiece passing through, resulting in inaccurate flow and flow resistance parameters. In addition, the current flow and flow resistance test devices cannot accurately measure the medium containing bubbles. Utility Model Content

[0004] The present disclosure provides a flow resistance test device for flammable and explosive media to at least solve one of the technical problems existing in the prior art.

[0005] According to a first aspect of the present disclosure, a flow resistance test device for flammable and explosive media is provided, comprising:

[0006] Liquid storage tank, used to store the medium required for device testing;

[0007] An explosion-proof gear pump group is connected in series to the liquid storage tank, and is used to transport the medium in the liquid storage tank and provide the device with the pressure required for the medium circulation;

[0008] A self-supporting pressure reducing valve, which is arranged downstream of the explosion-proof gear pump group and connected in series between the explosion-proof gear pump group and the liquid storage tank, and is used to reduce the pressure of the medium so that the medium flow rate can be output stably;

[0009] An electric flow regulating valve, connected in series between the self-supporting pressure reducing valve and the liquid storage tank, for regulating the medium flow;

[0010] A mass flow meter, connected in series between the electric flow regulating valve and the liquid storage tank, for monitoring the medium flow;

[0011] A test piece to be tested is connected in series between the electric flow control valve and the mass flow meter, and differential pressure transmitters are connected in parallel at both ends of the test piece to be tested. The differential pressure transmitter is used to measure the differential pressure of the medium flowing through the test piece to be tested.

[0012] In one possible implementation manner, it further includes a back pressure valve, which is connected in series between the liquid storage tank and the mass flow meter to ensure a stable pressure of the test piece under test.

[0013] In one possible implementation, a check valve is further included, which is connected in series between the explosion-proof gear pump unit and the self-supporting pressure reducing valve to prevent the medium from flowing back.

[0014] In one embodiment, an oil filter is further included, which is connected in series between the check valve and the self-supporting pressure reducing valve to filter the medium.

[0015] In one embodiment, it further comprises an accumulator, which is connected in series between the oil filter and the self-supporting pressure reducing valve and is used to absorb the pressure pulsation generated by the operation of the explosion-proof gear pump group.

[0016] In one possible implementation, it further includes a honeycomb rectifying device, which is connected in series between the electric flow regulating valve and the self-supporting pressure reducing valve to increase the circulation of the medium and stabilize the flow of the medium.

[0017] In one possible implementation manner, the mass flow meter is electrically connected to the electric flow regulating valve via a closed-loop PID controller for micro-adjusting the medium flow value.

[0018] In one possible implementation manner, the liquid storage tank is further provided with an explosion-proof breathing port, and the explosion-proof breathing port is further provided with a fireproof breathable cap;

[0019] The liquid storage tank is also equipped with a liquid level meter for observing the liquid level state in the liquid storage tank.

[0020] In one possible implementation, it also includes an explosion-proof oil cooling unit connected in series with the liquid storage tank, which is used to extract the medium in the liquid storage tank and return the medium to the liquid storage tank after cooling.

[0021] In one possible implementation manner, it further includes a pressure testing mechanism, which is connected in series between the test piece to be tested and the electric flow regulating valve, and is used to test the pressure of the medium before it enters the test piece to be tested.

[0022] In one possible implementation manner, it further comprises a temperature testing mechanism, which is connected in series between the test piece to be tested and the electric flow regulating valve, and is used to test the temperature of the medium before it enters the test piece to be tested.

[0023] In one possible implementation manner, it further includes a balancing valve, which is connected in series to a pipeline between the first pressure measuring point of the tested test piece and the electric flow regulating valve.

[0024] Compared with the prior art, the advantages of the present application are: 1) The device of the present application can prevent the medium temperature from being too high when the explosion-proof gear pump group is running continuously at high pressure, thereby preventing the risk of spontaneous combustion or flash explosion, etc. by setting an explosion-proof oil cooling unit; 2) The device of the present application can achieve precise control of the medium flow by setting an electric flow control valve and a mass flow meter, thereby obtaining accurate flow parameters and flow resistance parameters; 3) The device of the present application solves the influence of bubbles in the medium on the differential pressure value during flow resistance measurement by setting a balancing valve; 4) The present application sets a self-supporting pressure reducing valve, an electric flow control valve and a back pressure valve to coordinate and test the entire device system to ensure the accuracy of the measurement data.

[0025] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0027] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0028] Figure 1 A schematic structural diagram of a flow rate and flow resistance test device for flammable and explosive media according to an embodiment of the present disclosure is shown;

[0029] Figure 2 A cross-sectional schematic diagram of a honeycomb rectifying device according to an embodiment of the present disclosure is shown.

[0030] Explanation of the numbers in the figure: liquid storage tank 1, explosion-proof oil cooling unit 2, explosion-proof gear pump unit 3, check valve 4, oil filter 5, accumulator 6, self-supporting pressure reducing valve 7, honeycomb rectifier 8, electric flow regulating valve 9, pressure testing mechanism 10, temperature testing mechanism 11, filling valve 12, differential pressure transmitter 13, test piece under test 14, mass flow meter 15, first hand valve 16, back pressure valve 17, drain valve 18, fireproof vent cap 19, second hand valve 20, third hand valve 21. DETAILED DESCRIPTION

[0031] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0032] This device is a test equipment designed and developed according to the test standards of relevant flow-through workpieces. It is suitable for the pressure resistance and flow characteristic tests of flow-through workpieces with different diameters and provides solutions for the resistance characteristic test principles and methods.

[0033] In order to truly reflect the actual use scenario of the pipeline, the medium uses aviation kerosene, which is the most commonly used fuel for power units of my country's military aircraft, civil aircraft and carrier-based aircraft. The flow resistance test device of this application is a test equipment designed and developed for fuel pipelines, including flow test, pipeline resistance test, and medium density test.

[0034] The fuel pipeline flow resistance test method is to measure the pressure loss generated when a certain flow rate and pressure of fuel passes through the fuel pipeline. That is, when the pipeline passes the specified flow rate and pressure, the pressure difference before and after the fuel pipeline is detected.

[0035] Therefore, the flow and pressure of the system must be able to be adjusted over a wide range. In order to meet the test technical standards and requirements, flameproof variable frequency motors and gear pumps are used as the power source of the system; electric flow control valves and mass flow meters are used to complete the test of system pressure, pressure difference and flow; and control valves and back pressure valves are used to achieve the adjustment of system pressure and flow.

[0036] Based on this, according to one embodiment of the present disclosure, the utility model provides a flow resistance test device for flammable and explosive media, comprising: a liquid storage tank 1, the liquid storage tank 1 is used to store the flammable and explosive media required for the device test;

[0037] An explosion-proof gear pump group 3, which is connected in series to the liquid storage tank 1, and is used to transport the medium in the liquid storage tank 1 and provide the device with the pressure required for the medium circulation;

[0038] A self-supporting pressure reducing valve 7, which is arranged downstream of the explosion-proof gear pump group 3 and connected in series between the explosion-proof gear pump group 3 and the liquid storage tank 1, and is used to reduce the pressure of the medium so that the medium flow rate can be output stably;

[0039] An electric flow regulating valve 9, which is connected in series between the self-supporting pressure reducing valve 7 and the liquid storage tank 1, and is used to regulate the medium flow;

[0040] A mass flow meter 15, which is connected in series between the electric flow regulating valve 9 and the liquid storage tank 1, and is used to monitor the medium flow;

[0041] A test piece 14 is connected in series between the electric flow control valve 9 and the mass flow meter 15 , and differential pressure transmitters 13 are connected in parallel at both ends of the test piece 14 . The differential pressure transmitter 13 is used to measure the differential pressure of the medium flowing through the test piece 14 .

[0042] For example, the liquid storage tank 1 is provided with a liquid filling port, a liquid outlet, a discharge port, an explosion-proof breathing port, a liquid inlet of a cooling device, and a liquid return port of a cooling device, wherein the liquid filling port of the liquid storage tank 1 is connected to a filling valve 12, and the liquid storage tank 1 is filled with a medium through the filling valve 12. A first hand valve 16 is provided between the liquid outlet of the liquid storage tank 1 and the explosion-proof gear pump group 3, and is used to control the circulation or closing of the medium through the first hand valve 16. The discharge port provided on the liquid storage tank 1 is also connected to a drain valve 18, and is used to discharge the medium in the liquid storage tank 1.

[0043] The liquid storage tank 1 is welded from 304 stainless steel, with the inner wall polished to ensure the cleanliness of the liquid and prevent other non-metallic or carbon steel materials from corroding or rusting and contaminating the medium. It is a non-pressure container, but in order to prevent the closed container system from forming a negative pressure in the tank, an explosion-proof breathing port is reserved, and a fireproof breather cap 19 is also provided on the explosion-proof breathing port. If necessary, a liquid level gauge can be added to observe the liquid level state, that is, a liquid level gauge is provided in the liquid storage tank 1 to observe the liquid level state in the liquid storage tank 1.

[0044] For example, the explosion-proof gear pump group 3 uses a 2CY2.1-2.5 gear oil pump with a stainless steel housing, a suction range of 1-2 meters, and a maximum flow rate of 2.1M 3 / h, the maximum output pressure is 2.5Mpa. The motor of the explosion-proof gear pump group 3 can be driven by a frequency converter, which adjusts the speed of the pump group motor to control the output pressure through the pressure value of the pump outlet pipeline.

[0045] For example, the self-supporting pressure reducing valve 7 is a key control valve component of the device, with an inlet pressure of 2Mpa and an outlet pressure of 0.2-0.5Mpa (adjustable). Its main purpose is to obtain a relatively stable and steady medium flow output by reducing pressure through pressure loss, eliminating and absorbing turbulence caused by flow fluctuations and vibrations at the high-pressure end.

[0046] For example, the flow characteristic of the electric flow regulating valve 9 is the relationship between the relative flow rate of the medium flowing through the electric flow regulating valve 9 and its opening under the condition that the pressure difference at both ends of the valve remains constant. The flow characteristics of the electric flow regulating valve 9 are: linear characteristics, equal percentage characteristics and parabolic characteristics. It is widely used in system flow, pressure regulation and control systems. The mass flowmeter 15 uses an explosion-proof product manufactured by Qingdao Aowei, which can monitor volume flow, mass flow, density, temperature and other parameters in real time, and can be uploaded to the control system through communication; compared with other flow meters, its flow measurement range is wider. And preferably, the electric flow regulating valve 9 and the mass flowmeter 15 are electrically connected through a closed-loop PID controller for micro-adjusting the medium flow value. The PID controller makes micro-adjustments to the electric flow regulating valve 9 according to the flow value fed back by the mass flowmeter 15 to achieve precise control.

[0047] A differential pressure transmitter 13 is connected in parallel at both ends of the test piece 14 to measure the differential pressure of the medium flowing through the test piece 14. Figure 1 As shown, the connection points between the test piece 14 and the differential pressure transmitter 13 are set as the first pressure measuring point P1 and the second pressure measuring point P2 respectively. When the medium enters the test piece 14 from the first pressure measuring point P1 and then flows out from the second pressure measuring point P2, the differential pressure transmitter 13 measures the differential pressure value of the medium flowing through the first pressure measuring point P1 and the second pressure measuring point P2, and detects the volume flow rate and mass flow rate of the medium through the mass flowmeter 15, so that the flow parameters and flow resistance parameters of the medium can be accurately obtained based on these flow values ​​and differential pressure values.

[0048] Because the flow rate and flow resistance are directly proportional when the pipeline has the same length and flow area, that is to say, flow fluctuation has a direct impact on flow resistance. The device of the present application mainly satisfies 0.001FS% of the system flow regulation control accuracy (or flow fluctuation range) within the set flow value.

[0049] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes a back pressure valve 17 , which is connected in series between the liquid storage tank 1 and the mass flow meter 15 to ensure a stable pressure of the test piece 14 under test.

[0050] In one embodiment, the flow resistance test device for flammable and explosive media of the present application also includes a check valve 4, which is connected in series between the explosion-proof gear pump group 3 and the self-supporting pressure reducing valve 4 to prevent water hammer caused by medium backflow or instantaneous stop of the explosion-proof gear pump group.

[0051] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes an oil filter 5, which is connected in series between the check valve 4 and the self-supporting pressure reducing valve 7 to filter the medium. The oil filter 5 has a filtration accuracy of 1um to prevent the particles contained in the medium from damaging the precision instruments and sensors.

[0052] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes an accumulator 6, which is connected in series between the oil filter 5 and the self-supporting pressure reducing valve 7, and is used to absorb the pressure pulsation generated by the operation of the explosion-proof gear pump group 3. The main purpose of the accumulator 6 (or damper) is to absorb the pulsation generated by the operation of the gear pump and play a role in stabilizing the pressure.

[0053] In one embodiment, the flow resistance test device for flammable and explosive media of the present application also includes a honeycomb rectifier 8, which is connected in series between the electric flow regulating valve 9 and the self-supporting pressure reducing valve 7 to increase the circulation of the medium and stabilize the flow of the medium.

[0054] The honeycomb rectifying device 8, also known as the honeycomb flow stabilizing device, is a core body composed of multiple hexagonal structures processed in a shell-and-tube structure. The cross-sectional structure of the core body is as follows: Figure 2 As shown: the core is a stable structure formed by connecting multiple hexagonal channels, which can effectively utilize space, increase flow capacity, and at the same time play an auxiliary role in stabilizing flow.

[0055] In one embodiment, the flow resistance test device for flammable and explosive media of the present application also includes an explosion-proof oil cooling unit 2 connected in series with the liquid storage tank, and the explosion-proof oil cooling unit 2 is used to extract the medium in the liquid storage tank 1 and return the medium to the liquid storage tank 1 after cooling. Specifically, the liquid storage tank 1 is connected to the explosion-proof oil cooling unit 2 through the cooling device liquid inlet and the oil-resistant hose it has, and the explosion-proof oil cooling unit 2 is also connected to the cooling device liquid return port of the liquid storage tank 1 through the oil-resistant hose. In addition, a plurality of second hand valves 20 are provided on the oil-resistant hose between the cooling device liquid inlet and the explosion-proof oil cooling unit 2, and a plurality of third hand valves 21 are provided on the oil-resistant hose between the cooling device liquid return port and the explosion-proof oil cooling unit 2, and the flow of the medium is controlled by the second hand valve 20 and the third hand valve 21.

[0056] The explosion-proof oil cooling unit 2 is of air-cooled type and is equipped with an explosion-proof refrigerator to prevent the medium temperature from being too high when the explosion-proof gear pump unit 3 is running continuously at high pressure, thereby causing risks such as spontaneous combustion or flash explosion; the explosion-proof oil cooling unit 2 is connected to the liquid storage tank 1 with an oil-resistant hose, and the hose is connected with an O-ring 24° cone hydraulic joint to ensure sealing without leakage.

[0057] The explosion-proof oil cooling unit 2 is used to cool the medium in the liquid storage tank 1. For example, the explosion-proof oil cooling unit 2 can monitor the medium temperature in the liquid storage tank 1 in real time. When the set value is reached, the explosion-proof oil cooling unit 2 starts to work, extracts the medium and cools the medium, and the cooled medium flows back to the liquid storage tank 1.

[0058] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes a pressure test mechanism 10, which is connected in series between the first pressure measuring point P1 of the tested test piece 14 and the electric flow regulating valve 9, and is used to test the pressure of the medium before entering the tested test piece 14. The pressure test mechanism 10 can be a pointer-type pressure gauge or a pressure sensor.

[0059] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes a temperature testing mechanism 11, which is connected in series between the first pressure measuring point P1 of the tested test piece 14 and the electric flow regulating valve 9, and is used to test the temperature of the medium before entering the tested test piece 14. The temperature testing mechanism 11 can be a pointer-type thermometer or a temperature sensor.

[0060] In one embodiment, the flow resistance test device for flammable and explosive media of the present application further includes a balancing valve, which is connected in series to the pipeline between the first pressure measuring point P1 of the tested test piece 14 and the electric flow regulating valve 9. For the differential pressure value measurement of the pressure taking point, a balancing valve (or a three-valve group) is installed. When the entire device system is running, the balancing valve needs to be opened to exhaust the air in the system pipeline, and the detection data collection can be started after the liquid is emptied.

[0061] In one embodiment, the flow resistance test device for flammable and explosive media of the present application also includes a controller, which can be a single-chip microcomputer or a PLC controller. The controller can be electrically connected to the explosion-proof oil cooling unit 2, the explosion-proof gear pump group 3, the accumulator 6, the temperature sensor 11, the pressure sensor 10, the mass flow meter 15, and the differential pressure transmitter 13 to control their opening or closing.

[0062] The working process of the flow resistance test device for flammable and explosive media of the present application is specifically described below: open the first hand valve 16, the second hand valve 20, and the third hand valve 21, close the drain valve 18, start the explosion-proof and explosion-proof gear pump group 3, and start conveying the medium. The medium passes through the check valve 4, the oil filter 5, the accumulator 6, and the self-supporting pressure reducing valve 7 in sequence. The self-supporting pressure reducing valve 7 reduces the pressure of the medium and outputs the medium flow steadily. The medium after the pressure reduction passes through the honeycomb rectifier 8, and the honeycomb rectifier 8 assists the medium in stabilizing the flow. The medium after the stabilizing flow passes through the electric flow regulating valve 9, and the flow of the medium is adjusted by the electric flow regulating valve 9. Then the medium enters the test piece 14 under test through the first pressure measuring point P1, and the medium flowing out of the test piece 14 passes through the second pressure measuring point P2, the mass flowmeter 15, and the back pressure valve 17 and then flows into the liquid storage tank 1, wherein the differential pressure transmitter 13 measures the differential pressure value before and after the medium passes through the test piece 14 under test (that is, the differential pressure value of the second pressure measuring point P2 and the first pressure measuring point P1).

[0063] It should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are contradictory.

[0065] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A flow resistance test device for flammable and explosive media, characterized in that: include: Liquid storage tank, used to store the medium required for device testing; An explosion-proof gear pump group is connected in series to the liquid storage tank, and is used to transport the medium in the liquid storage tank and provide the device with the pressure required for the medium circulation; A self-supporting pressure reducing valve, which is arranged downstream of the explosion-proof gear pump group and connected in series between the explosion-proof gear pump group and the liquid storage tank, and is used to reduce the pressure of the medium so that the medium flow rate can be output stably; An electric flow regulating valve, connected in series between the self-supporting pressure reducing valve and the liquid storage tank, for regulating the medium flow; A mass flow meter, connected in series between the electric flow regulating valve and the liquid storage tank, for monitoring the medium flow; A test piece to be tested is connected in series between the electric flow control valve and the mass flow meter, and differential pressure transmitters are connected in parallel at both ends of the test piece to be tested. The differential pressure transmitter is used to measure the differential pressure of the medium flowing through the test piece to be tested.

2. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: It also includes a back pressure valve, which is connected in series between the liquid storage tank and the mass flow meter to ensure a stable pressure of the test piece being tested.

3. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: It also includes a check valve, which is connected in series between the explosion-proof gear pump group and the self-supporting pressure reducing valve to prevent the medium from flowing back.

4. A flow resistance test device for flammable and explosive media according to claim 3, characterized in that: It also includes an oil filter, which is connected in series between the check valve and the self-supporting pressure reducing valve and is used for filtering the medium.

5. A flow resistance test device for flammable and explosive media according to claim 4, characterized in that: It also includes an accumulator, which is connected in series between the oil filter and the self-supporting pressure reducing valve and is used to absorb the pressure pulsation generated by the operation of the explosion-proof gear pump group.

6. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: It also includes a honeycomb rectifying device, which is connected in series between the electric flow regulating valve and the self-supporting pressure reducing valve, and is used to increase the circulation of the medium and stabilize the flow of the medium.

7. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: The mass flow meter is electrically connected to the electric flow regulating valve via a closed-loop PID controller for micro-adjusting the medium flow value.

8. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: The liquid storage tank is also provided with an explosion-proof breathing port, and the explosion-proof breathing port is also provided with a fireproof ventilation cap; The liquid storage tank is also equipped with a liquid level meter for observing the liquid level state in the liquid storage tank.

9. A flow resistance test device for flammable and explosive media according to claim 1, characterized in that: It also includes an explosion-proof oil cooling unit connected in series with the liquid storage tank, which is used to extract the medium in the liquid storage tank and return the medium to the liquid storage tank after cooling.

10. A flow resistance test device for flammable and explosive media according to any one of claims 1 to 9, characterized in that: It also includes a pressure testing mechanism, which is connected in series between the test piece and the electric flow regulating valve, and is used to test the pressure of the medium before it enters the test piece; It also includes a temperature testing mechanism, which is connected in series between the test piece and the electric flow regulating valve, and is used to test the temperature of the medium before it enters the test piece; It also includes a balancing valve, which is connected in series on a pipeline between the first pressure measuring point of the tested test piece and the electric flow regulating valve.

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