CN115876397A - Testing device and method for detecting leakage rate of hydrogen-doped pipeline connecting piece and sealing piece - Google Patents

Abstract

The invention provides a device and a method for detecting the leakage rate of a hydrogen-doped pipeline connecting piece and a sealing piece, comprising the following steps: a sealing module and a detection unit; the sealing module comprises a hydrogen-doped gas cylinder, a high-pressure pump and a high-low temperature box which are sequentially connected, a to-be-detected piece is installed in the high-low temperature box, and one end of the high-low temperature box is connected with the detection unit; the detection unit comprises a drainage method detection unit and a differential pressure method detection unit, and leakage detection data are obtained by the detection unit, so that leakage rate data are continuously optimized, and the sealing performance of the pipeline connecting piece and the sealing piece is improved.

Description

Experimental device and method for detecting leakage rate of hydrogen-doped pipeline connectors and seals

technical field

The invention belongs to the technical field of detection of pipeline connectors and seals, and in particular relates to an experimental device and method for detecting the leakage rate of hydrogen-doped pipeline connectors and seals.

Background technique

At present, hydrogen transportation methods can be pipeline transportation, high-pressure gas cylinder transportation, liquid hydrogen tank truck transportation, etc., but long-distance pipeline transportation is easier to realize long-distance and large-scale transportation of hydrogen, so mixing hydrogen into natural gas pipeline transportation is currently the most best way. At present, the development of hydrogen-doped natural gas pipeline transportation industry at home and abroad is still in its infancy. Although there are many related researches and projects, there are still many problems to be solved.

In long-distance pipeline transportation, the connection between pipe sections can be realized by using flanges, and the sealing ring or gasket in the flange can further improve the sealing and safety of the flange, and the welding process can also realize the connection between pipe sections. The connection, and the commonly used valves (ball valve and globe valve) in the pipeline can not only realize the flow regulation function, but also realize the pipe section connection function. In the process of transporting pure hydrogen/hydrogen-doped natural gas, the above-mentioned flange seals, pipeline welds and valves will leak, and it is found by comparison that the hydrogen permeation coefficient of elastomer materials such as rubber used as seals is higher than that of Non-metallic materials used as tubing have much higher hydrogen permeation coefficients, reducing the safety of gas delivery. Therefore, optimizing the tightness of pipeline connectors and seals and reducing their leakage rate are of great significance for the safe transportation of hydrogen-doped natural gas pipelines.

Existing air tightness detection methods are diversified, such as bubble detection method, flow detection method and helium gas detection method. The air bubble detection method can determine whether the workpiece leaks and the location of the leakage. This detection method is simple to operate and low in cost, but this method is inefficient. At the same time, after the detection is completed, the measured workpiece must be dried and rust-proofed; Quantitatively detect the leakage of the workpiece under test. For workpieces with small leakage, the flow detection method will take a long time, so this detection method is suitable for workpieces with large leakage; the helium gas detection method can quantitatively calculate the leakage of the workpiece , but the cost of this detection method is high, and the volume of the airtight container determines that it is difficult to detect large workpieces, and the leakage of helium into the atmosphere will cause damage to the environment.

The pipeline transportation of pure hydrogen/hydrogen-doped natural gas is in its infancy, and some technologies are not well developed. The gas leakage at flange sealing components, pipeline welding and valves is relatively small. The air tightness testing for micro-leakage exists as follows Problem: There are few micro-leakage detection methods, and the detection accuracy and efficiency cannot be guaranteed. At the same time, the detection cycle is long, which consumes more material and manpower. For flange seals, how do hydrogen doping ratio, working pressure, ambient temperature, bolt pre-tightening force, flange seal size, flange sealing surface form and seal ring/gasket material type affect the leakage rate? Seam pipes, hydrogen doping ratio, working pressure, ambient temperature, pipe size, weld size, and how the welding process affects the leakage rate; for valves, hydrogen doping ratio, working pressure, ambient temperature, valve size and type, valve gasket size And how does the type of material affect the leakage rate? The above three issues lack quantitative research conclusions, which are urgent problems to be solved for safe pipeline transportation.

Contents of the invention

In order to solve the above problems, the present invention proposes an experimental device for detecting leakage rate of hydrogen-doped pipeline connectors and seals based on micro-leakage air-tightness detection and high-precision requirements, combined with the actual operating conditions of hydrogen-doped/pure hydrogen pipelines According to the invention and the method, the device can realize the air tightness detection of the flange sealing part, the welding seam of the pipeline and the valve part.

According to some embodiments, the present invention adopts the following technical solutions:

In the first aspect, the present invention provides an experimental device for detecting the leakage rate of hydrogen-doped pipeline connectors and seals, including a high and low temperature box, a control unit, a pressure relief unit and a detection unit; the interior of the high and low temperature box is used to place the For the test piece, the gas supply unit inflates air into the piece to be tested, which includes an air intake pipe, a stainless steel cylinder, a pressure gauge and an automatic shut-off valve. The stainless steel cylinder is used to store hydrogen-doped gas, and the air intake pipe is connected to the stainless steel cylinder. A pressure gauge and an automatic shut-off valve are set on the top; the control unit includes a high-pressure pump, a pipeline check valve, and a pressure sensor installed on the intake pipe in sequence; the pressure relief unit is also arranged on the intake pipe; the detection unit communicates with the The parts to be tested are connected to detect the gas leakage rate.

As a further technical solution, the pressure relief unit includes a parallel manual pressure relief valve and an automatic pressure relief valve, and the manual pressure relief valve and the automatic pressure relief valve are connected to the stainless steel cylinder through a pressure relief pipeline.

As a further technical solution, it also includes a valve pneumatic energy supply unit. The valve pneumatic energy supply unit includes sequentially connected pre-increase air inlets, air duplexes, pressure reducing valves, air pressure gauges and solenoid valves. The solenoid valves are connected to Manual pressure relief valve, valve pneumatic power supply unit provides air power for manual pressure relief valve and vacuum pneumatic generator.

As a further technical solution, the detection unit includes a drainage method detection unit and a pressure difference method detection unit.

As a further technical solution, the drainage detection unit includes a leak detection tube, a measuring cup, and a water tank. The measuring cup is placed in the water tank, and the gas leaked from the piece to be tested flows through the leak detection tube through the through hole and enters the measuring cup. The amount of change in the water level, the volume of the liquid level rise is the volume of the leaked gas.

As a further technical solution, the differential pressure method detection unit includes a leak detection tube, a negative pressure sensor, a vacuum valve, and a pneumatic vacuum generator. The pneumatic vacuum generator reduces the pressure in the leak detection tube to vacuum, and the leakage The gas increases the pressure in the leak detection tube, and the pressure change in the leak detection tube is collected in real time through a negative pressure sensor to obtain leak detection data.

As a further technical solution, the pneumatic vacuum generator is also connected to the valve pneumatic energy supply unit, and the pneumatic vacuum generator is powered by the valve pneumatic energy supply unit.

As a further technical solution, the air intake pipe and the object to be detected are threadedly fitted.

As a further technical solution, the leakage pipe and the piece to be detected are fitted through threads.

In a second aspect, the present invention provides a working method of a hydrogen-doped pipeline connector and a leak rate detection experimental device for seals, including:

Select the appropriate hydrogen-doped ratio according to the experimental requirements, and the gas in the hydrogen-doped gas cylinder will display the pressure in real time through the pressure gauge, and then boost the pressure to the specified pressure through the high-pressure pump;

The hydrogen-doped gas boosted by the high-pressure pump flows through the pipeline check valve, pressure gauge and pressure sensor to fill the test piece, and the test piece is placed in a high and low temperature box;

For hydrogen, the drainage method detection unit and the pressure difference detection unit are used for detection, and the detected data are transmitted to the processor in real time, and the volume-time curve and pressure-time curve are drawn;

At the end of the experiment, the hydrogen-doped gas in the pipeline can be released by manual pressure relief valve and automatic pressure relief valve, and the released gas can be returned to the hydrogen-doped gas cylinder.

Compared with prior art, the beneficial effect of the present invention is:

1. The sealing module in the present invention includes a hydrogen-doped gas cylinder, a high-pressure pump, and a high-low temperature box connected in sequence. The test piece is installed in the high-low temperature box, and one end of the high-low temperature box is connected to a detection unit, and leak detection data can be obtained by using the detection unit; The set of procedures has multiple functions. First, it can conduct leakage rate detection experiments on multiple components (flange seals, pipes and valves with welds); second, it can conduct leakage detection experiments under multi-factor coupling. The tightness of the sealing components can solve the problem of safe delivery of hydrogen-doped/pure hydrogen.

2. The present invention can compare the accuracy of leak detection, adopt the drainage method and the pressure difference method, and then compare the accuracy of the two detection methods, and provide a high-precision detection method for micro-leakage detection.

3. The present invention can explore the influence rules of multiple factors on hydrogen-doped/pure hydrogen pipeline connectors and seals; for flange seals, it can explore hydrogen-doped ratio, working pressure, ambient temperature, bolt pre-tightening force, flange seal Quantitative influence of part size, flange sealing surface form (flat and raised surface) and sealing ring/gasket material type (nitrile rubber, PTFE rubber, metal wound gasket) on the leakage rate; For pipes with joints, the quantitative influence of hydrogen doping ratio, working pressure, ambient temperature, pipe size, weld size and welding process on the leakage rate can be explored; for valves, hydrogen doping ratio, working pressure, ambient temperature, valve size can be explored Quantitative effects of type and type, valve gasket size and material type on leakage rate.

4. The air inlet pipe of the present invention and the test piece and between the test piece and the leak detection pipe are threadedly connected, which is convenient for disassembly, has a high safety factor, a long service life, and is easy to maintain.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention.

Fig. 1 is the schematic structural view of the hydrogen-doped pipeline connector and seal leakage rate detection experimental device of embodiment one;

2 is a schematic diagram of the detection principle of the flange-rubber O-ring-bolt leakage rate with grooves provided in Embodiment 1;

Fig. 3 is a schematic diagram of the detection principle of the raised surface flange-metal wound gasket-bolt leakage rate in the first embodiment;

Fig. 4 is a schematic diagram of the detection principle of the leakage rate at the weld of the pipeline in Embodiment 1;

Fig. 5 is the schematic diagram of the detection principle of the leakage rate of the ball valve in the first embodiment;

Fig. 6 is a schematic diagram of the detection principle of the shut-off valve leakage rate in the first embodiment.

In the figure: 1-1-vacuum pneumatic generator, 1-2-measuring cup, 1-3-intake pipe, 1-4-leak detection pipe, 1-5-high and low temperature box, 1-6-flange cover, 1-7-flange lower cover, 1-8-O-ring;

2-1-vacuum pneumatic generator, 2-2-measuring cup, 2-3-intake pipe, 2-4-leak detection pipe, 2-5-high and low temperature box, 2-6-flange cover, 2-7 - Flange lower cover, 2-8-metal wound gasket;

3-1-vacuum pneumatic generator, 3-2-measuring cup, 3-intake pipe, 3-4-leak detection pipe, 3-5-high and low temperature box, 3-6-sealing box, 3-7-welding seam;

4-1-vacuum pneumatic generator, 4-2-measuring cup, 4-3-intake pipe, 4-4-leak detection pipe, 4-5-high and low temperature box, 4-6-seal box, 4-7-flow road;

5-1-vacuum pneumatic generator, 5-2-measuring cup, 5-3-intake pipe, 5-4-leak detection pipe, 5-5-high and low temperature box, 5-6-sealing, 5-7-flow channel .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that the terminology used here is only for describing specific embodiments, and is not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

Embodiment one:

As shown in Figure 1, this embodiment provides an experimental device for detecting the leakage rate of hydrogen-doped pipeline connectors and seals, including a sealing module and a detection unit;

The sealing module is composed of five parts: a gas supply unit, a control unit, a pressure relief unit, a valve pneumatic energy supply unit, and a test piece. Specifically, it includes a stainless steel gas cylinder, a pressure gauge, an automatic shut-off valve, and a high-pressure pump connected in sequence. , pipeline check valve, pressure gauge, pressure sensor and high and low temperature box, the test piece is installed in the high and low temperature box, and one end of the high and low temperature box is also connected to the detection unit; the pipeline between the pipeline check valve and the pressure sensor is also connected Connect the input end of the manual pressure relief valve and the input end of the automatic pressure relief valve, and connect the output end of the manual pressure relief valve and the output end of the automatic pressure relief valve to the input port of the stainless steel gas cylinder.

The above-mentioned high and low temperature box is mainly used to simulate the temperature of the environment where the test piece is located, so that the experimental device is closer to the actual working condition.

In this embodiment, the above-mentioned gas supply unit is composed of a stainless steel gas cylinder, a pressure gauge and an automatic shut-off valve. According to the experimental requirements, an appropriate hydrogen doping ratio is selected. The gas in the hydrogen doped gas cylinder displays the pressure in real time through the pressure gauge, and then passes Boost the pressure to the specified pressure; then you can explore the leakage of the tested parts under different hydrogen doping ratios and working pressures.

In this embodiment, the above-mentioned control unit is composed of a high-pressure pump, a pipeline check valve, a pressure sensor and a high and low temperature box. The hydrogen-doped gas boosted by the high-pressure pump flows through the pipeline check valve, pressure gauge and pressure sensor to fill To the flange to seal the test piece, in order to change the ambient temperature, the test piece is placed in a high and low temperature box; the control unit can control the temperature of the high and low temperature box, the pressure of the intake pipe, etc.; and then it can explore different hydrogen doping ratios and working pressures. Leakage of the tested parts.

In this embodiment, the above-mentioned pressure relief unit is composed of a manual pressure relief valve and an automatic pressure relief valve. The gas can be returned to the hydrogen-doped cylinder for recycling.

Further, the sealing module also includes a valve pneumatic energy supply unit, and the valve pneumatic energy supply unit includes a pre-increasing inlet, an air duplex, a pressure reducing valve, an air pressure gauge and a solenoid valve arranged in sequence. The valve is connected with the manual pressure relief valve, and the valve pneumatic energy supply unit provides air power for the manual pressure relief valve and the vacuum pneumatic generator.

Further, the detection unit includes a drainage method detection unit and a differential pressure detection unit, and the instrument composed of each part will be described below.

Further, the detection unit of the drainage method includes a leak detection tube, a measuring cup and a water tank. If the drainage method is used for detection, the gas leaking from the piece to be tested flows through the leak detection tube through the through hole and enters the measuring cup, and the water level in the measuring cup is recorded. The volume of the liquid level rises is the volume of the leaked gas, and the volume-time curve is drawn;

Further, the above-mentioned differential pressure method detection unit includes a negative pressure sensor, a vacuum valve and a pneumatic vacuum generator, and the pneumatic vacuum generator is used to reduce the pressure in the leak detection tube to vacuum, and the leaking gas increases the pressure in the leak detection tube, The pressure change in the leak detection pipe is collected in real time through the negative pressure sensor to obtain the leak detection data, and the pressure-time curve is drawn. The pneumatic vacuum generator is also connected to the valve pneumatic energy supply unit of the sealing module, and the pneumatic vacuum generator is also powered by the valve pneumatic energy supply unit.

The present invention can compare the accuracy of leak detection by setting two different detection units, adopts two detection technologies of drainage method and pressure difference method, and then compares the accuracy of the two detection methods, and provides a high-precision detection method for micro-leakage detection.

Furthermore, the pneumatic energy supply unit of the valve is composed of an air duplex, a pressure reducing valve, an air pressure gauge and a solenoid valve; the experimental device is in a hydrogen-doped condition, and in order to ensure safety, the valve through which the hydrogen flows is powered by an air source. switch. Valve pneumatic energy supply process: Air enters from the prefabricated air inlet and is compressed. In order to improve the service life of the equipment, the compressed air passes through the air duplex to filter other impurities to purify the air. The purified compressed air passes through the pressure reducing valve to reduce the pressure, and passes through the pressure gauge. The air pressure is displayed in real time. The air pressure gauge is connected to the solenoid valve and the pneumatic vacuum generator. The air flowing through the solenoid valve enters the manual pressure relief valve to provide power for the switch of the manual pressure relief valve and the pneumatic vacuum generator.

Further, as shown in Figure 2, it is a schematic diagram of the detection of the flange-rubber O-ring-bolt leakage rate with grooves; the tested part includes the flange end cover and the flange base, and the flange base is provided with two One of the sealing rings is equipped with a rubber O-ring and an auxiliary sealing ring, and bolt holes are set on the flange end cover and the flange base; Gas; set a through hole on the flange end cover, the through hole communicates with the mating surface of the flange end cover and the flange base, and connects the through hole with the leak detection tube; then, the leak rate detection is performed.

Further, as shown in Figure 3, it is a schematic diagram of the detection principle of the raised surface flange-metal wound gasket-bolt leakage rate; the tested parts include the flange end cover and the flange base, and the flange base and the flange end cover Two metal wound gaskets and auxiliary gaskets are set between them, and two through holes are set on the flange end cover, which are through hole 1 (air intake hole) and through hole 2 (air leakage hole); among them, through hole 1 It communicates with the gap formed by the metal wound gasket, the flange end cover and the flange base, and the second through hole communicates with the gap formed by the auxiliary gasket, the metal wound gasket, the flange end cover and the flange base; the through hole one connects with the The air intake pipe is connected, and the second through hole is connected with the leak detection pipe; then, the leakage rate detection is carried out.

Further, as shown in Figure 4, it is a schematic diagram of the detection principle of the leakage rate at the weld of the pipeline; wherein the detected part is a pipeline with a weld, and the two ends of the pipeline are sealed, and a through hole is opened at the air inlet end; the pipeline is placed In the sealed box, the air inlet pipe is connected with the end of the through hole of the pipeline, and the air is inflated into the pipeline, and the leak detection tube is connected with the inside of the sealed box, and then the leakage rate is detected.

Further, as shown in Figure 5, the schematic diagram of the detection principle of the ball valve leakage rate, wherein the tested part is a ball valve, both ends of which are sealed, and the ball valve is placed in a sealed box, and the air inlet pipe is connected to the flow channel of the ball valve to inflate the ball valve; leak detection The tube is connected to the inside of the sealed box, and then, the leak rate test is carried out.

Further, as shown in Figure 6, the schematic diagram of the detection principle of the shut-off valve leakage rate, in which the detected part is a shut-off valve, both ends of which are sealed, and the shut-off valve is placed in a sealed box, and the intake pipe is connected to the flow channel of the shut-off valve, and is connected to the shut-off valve. The interior is filled with air; the leak detection tube is connected to the inside of the sealed box, and then the leak rate detection is carried out.

Between the above air inlet pipe and the test piece (flange upper end cover, pipe weld, ball valve, globe valve) and between the test piece (flange upper end cover, pipe weld seam, ball valve, globe valve) and the leak detection pipe Threaded connection is used between them, which is convenient for disassembly, high safety factor, long life and easy maintenance.

The device in this embodiment can explore the influence of multiple factors on the hydrogen-doped/pure hydrogen pipeline connection and seal; Quantitative influence of flange seal size, flange sealing surface form (flat and raised surface) and sealing ring/gasket material type (nitrile rubber, polytetrafluoroethylene rubber, metal wound gasket) on the leakage rate; For pipes with welds, it is possible to explore the quantitative influence of hydrogen doping ratio, working pressure, ambient temperature, pipe size, weld size, and welding process on the leakage rate; for valves, it is possible to explore the hydrogen doping ratio, working pressure, ambient temperature, Quantitative influence of valve size and type, valve gasket size and material type on leakage rate.

Embodiment two:

This embodiment provides the working method of the hydrogen-doped pipeline connector and seal leakage rate detection experimental device, including:

① Select the appropriate hydrogen-doped ratio according to the experimental requirements. The gas in the hydrogen-doped gas cylinder displays the pressure in real time through the pressure gauge, and then boosts the pressure to the specified pressure through the high-pressure pump.

②The hydrogen-doped gas boosted by the high-pressure pump flows through the pipeline check valve, pressure gauge and pressure sensor and fills the flange to seal the test piece. In order to change the ambient temperature, the test piece is placed in a high and low temperature box.

③ For hydrogen, if the pressure difference method is used for detection, the pressure in the leak detection tube is reduced to vacuum by using a vacuum pneumatic generator, the leaking gas increases the pressure in the leak detection tube, and the pressure in the leak detection tube is reduced by a negative pressure sensor. The pressure change is collected in real time to obtain the leak detection data, and the pressure-time curve is drawn; if the drainage method is used for detection, the gas leaked from the test piece flows through the through hole through the detection tube into the measuring cup, and the change of the water level in the measuring cup is recorded. The volume of the bit rise is the volume of the leaked gas, and the volume-time curve is drawn.

④The experimental device is in the hydrogen-doped condition. To ensure safety, the valve through which the hydrogen flows is powered by an air source to realize the switch. Valve pneumatic energy supply process: Air enters from the prefabricated air inlet and is compressed. In order to improve the service life of the equipment, the compressed air passes through the air duplex to filter other impurities to purify the air. The purified compressed air passes through the pressure reducing valve to reduce the pressure, and passes through the pressure gauge. The air pressure is displayed in real time. The air pressure gauge is connected to the solenoid valve and the pneumatic vacuum generator. The air flowing through the solenoid valve enters the manual pressure relief valve to provide power for the switch of the manual pressure relief valve and the pneumatic vacuum generator.

⑤ At the end of the experiment, the hydrogen-doped gas in the pipeline can be released by manual pressure relief valve or automatic pressure relief valve, and the released gas can be returned to the hydrogen-doped gas cylinder.

The high-pressure pump, pneumatic vacuum generator and digital display meter in this embodiment are all automatically controlled, which is convenient for operation and data recording.

To sum up, the present invention provides a set of procedures to realize multifunctional experiments. One is that the leakage rate detection experiment can be carried out on multi-components (flange seals, pipes and valves with welds); the other is that the leakage detection experiment under multi-factor coupling can be carried out, and the sealing performance of the sealing components can be improved by studying the data obtained, which can Solve problems for the safe delivery of hydrogen-doped/pure hydrogen.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (10)

1. A leakage rate detection experimental device for a hydrogen-doped pipeline connecting piece and a sealing piece is characterized by comprising a high-low temperature box, a control unit, a pressure relief unit and a detection unit; the high-low temperature box is used for placing a piece to be detected, the gas supply unit is used for charging gas into the piece to be detected and comprises a gas inlet pipe, a stainless steel gas cylinder, a pressure gauge and an automatic stop valve, the stainless steel gas cylinder is used for storing hydrogen-doped gas, the gas inlet pipe is connected with the stainless steel gas cylinder, and the pressure gauge and the automatic stop valve are arranged on the gas inlet pipe; the control unit comprises a high-pressure pump, a pipeline one-way valve and a pressure sensor which are sequentially arranged on the air inlet pipe; the pressure relief unit is also arranged on the air inlet pipe; the detection unit is connected with the to-be-detected piece through a leakage pipe and used for detecting the leakage rate of gas.

2. The experimental device for detecting the leakage rate of the hydrogen loading pipeline connecting piece and the sealing piece as claimed in claim 1, wherein the pressure relief unit comprises a manual pressure relief valve and an automatic pressure relief valve which are connected in parallel, and the manual pressure relief valve and the automatic pressure relief valve are connected with the stainless steel gas cylinder through a pressure relief pipeline.

3. The experimental device for detecting the leakage rate of the hydrogen-loading pipeline connecting piece and the sealing piece as claimed in claim 1, further comprising a valve pneumatic energy supply unit, wherein the valve pneumatic energy supply unit comprises a pre-aeration inlet, an air doublet, a pressure reducing valve, an air pressure gauge and an electromagnetic valve which are sequentially connected, the electromagnetic valve is connected with a manual pressure relief valve, and the valve pneumatic energy supply unit provides aerodynamic force for the manual pressure relief valve and the vacuum pneumatic generator.

4. The experimental apparatus for testing the leakage rate of the connecting member and the sealing member of the hydrogen-loading pipeline according to claim 1, wherein the detecting unit comprises a drainage detecting unit and a pressure difference detecting unit.

5. The experimental device for detecting the leakage rate of the hydrogen-doped pipeline connecting piece and the sealing piece as claimed in claim 4, wherein the drainage detection unit comprises a leakage detecting pipe, a measuring cup and a water tank, the measuring cup is placed in the water tank, gas leaked from the to-be-detected piece flows through the leakage detecting pipe into the measuring cup through the through hole, the variation of the water level in the measuring cup is recorded, and the rising volume of the water level is the volume of the leaked gas.

6. The experimental apparatus for detecting the leakage rate of the hydrogen-doped pipe connecting piece and the sealing piece according to claim 4, wherein the pressure difference detection unit comprises a leakage detecting pipe, a negative pressure sensor, a vacuum valve and a pneumatic vacuum generator, the pneumatic vacuum generator reduces the pressure in the leakage detecting pipe to vacuum, the leakage gas increases the pressure in the leakage detecting pipe, and the pressure change in the leakage detecting pipe is collected in real time through the negative pressure sensor to obtain the leakage detection data.

7. The experimental apparatus for testing the leakage rate of hydrogen loading pipe connectors and seals as claimed in claim 6, wherein said pneumatic vacuum generator is further connected to a valve pneumatic energy supply unit, and the valve pneumatic energy supply unit is used for supplying energy to drive the pneumatic vacuum generator.

8. The experimental device for detecting the leakage rate of the hydrogen-loaded pipeline connecting piece and the sealing piece as claimed in claim 6, wherein the air inlet pipe is in threaded fit with the piece to be detected.

9. The experimental device for detecting the leakage rate of the hydrogen-loading pipeline connecting piece and the sealing piece as claimed in claim 6, wherein the leakage pipe is in threaded fit with the piece to be detected.

10. A method of operating a leak rate testing apparatus for hydrogen loaded pipe connectors and seals as claimed in any one of claims 1 to 9, comprising:

selecting a proper hydrogen loading proportion according to experimental requirements, displaying the pressure of gas in the stainless steel gas cylinder in real time through a pressure gauge, and then boosting the pressure to a specified pressure through a high-pressure pump;

the hydrogen-doped gas boosted by the high-pressure pump flows through a pipeline check valve, a pressure gauge and a pressure sensor and is filled into a piece to be detected, and the piece to be detected is placed in a high-low temperature box;

aiming at hydrogen, a drainage method detection unit and a pressure difference method detection unit are adopted for detection, detected data are transmitted to a processor in real time, and a volume-time curve and a pressure-time curve are drawn;

and (4) discharging the hydrogen-loaded gas in the pipeline by adopting a manual pressure release valve and an automatic pressure release valve after the experiment is finished, and returning the discharged gas to the hydrogen-loaded gas cylinder.

Images