Hydrogen volume rate measuring system and method

Abstract

The invention discloses a hydrogen volume rate measuring system, which is arranged in a special hydrogen laboratory, an outlet of a hydrogen buffer tank is connected with a total pressure regulating valve, the other end of the total pressure regulating valve is communicated with a total flow switch ball valve, the other end of the total flow switch ball valve is communicated with a hydrogen mass flow meter, and the hydrogen mass flow meter is communicated with a hydrogen buffer tank. One end of the hydrogen mass flow meter is communicated with the gas inlet pressure regulating valve, the other end of the hydrogen mass flow meter is communicated with the gas inlet pressure regulating valve, and the other end of the gas inlet pressure regulating valve is communicated with the gas inlet flow regulating valve. And S2, measuring to obtain the rate. The hydrogen volume rate measuring system and the hydrogen volume rate measuring method provided by the invention aim to overcome the existing defects, can accurately detect the hydrogen pumping capacity of the vacuum pump, and are more accurate and convenient for an application end to select and judge the suitability of the vacuum pump.

Description

Technical Field

[0001] The invention relates to a hydrogen volume rate measurement system and method. Background Art

[0002] The volume rate of positive displacement vacuum pumps is now mainly implemented in accordance with the provisions and descriptions in the national standard. The commonly used method is the flow method. The national standard stipulates the measuring device, measuring equipment, measuring method, etc. However, the content described in the national standard is only suitable for the detection medium of air. The vacuum pump needs to be placed in an atmospheric environment for extraction. The atmosphere has the characteristics of stable air pressure and sufficient air volume.

[0003] When the medium to be measured is replaced with other gases, since the gas source needs to be artificially produced, problems such as insufficient gas supply and unstable pressure may occur. Therefore, there is currently no measurement system and method for the volume rate of other gases.

[0004] While the existing national standard specifies test equipment, test methods, and calculation methods, it only applies to air. For other gases, simply applying the national standard's equipment is essentially incapable of accurately measuring them. This also fails to address issues such as high pressure from artificial gas sources, unstable and insufficient gas volumes, and the incompatibility of air flow and pressure sensors with other gases, making it impossible to measure the volumetric rate of other gases. In particular, the national standard does not specify the test environment, nor does it address laboratory safety requirements for flammable and explosive gases.

[0005] Currently, the volumetric velocity of other gases is based on the measured volumetric velocity of air and is theoretically converted using gas density. This theoretical conversion is only for ideal conditions and cannot accurately simulate actual pipeline / gas source characteristics, resulting in inaccurate volumetric velocity curves and results.

[0006] Therefore, in order to solve the above problems, a hydrogen volume rate measurement system and method are proposed. Summary of the Invention

[0007] The purpose of the present invention is to overcome the existing defects and provide a hydrogen volume rate measurement system and method, which can accurately detect the vacuum pump's ability to pump hydrogen, and more accurately and conveniently facilitate the application end to select and determine the adaptability of the vacuum pump.

[0008] To achieve the above object, the present invention provides the following technical solution: a hydrogen volume rate measurement system, which is arranged in a dedicated hydrogen laboratory and includes a hydrogen buffer tank, a total pressure regulating valve, a total flow switching ball valve, a hydrogen mass flow meter, an inlet pressure regulating valve, an inlet flow regulating valve, an explosion-proof test cover, a vacuum pump to be tested, and an absolute vacuum gauge; The outlet of the hydrogen buffer tank is connected to the total pressure regulating valve, the other end of the total pressure regulating valve is connected to the total flow switch ball valve, the other end of the total flow switch ball valve is connected to the hydrogen mass flowmeter, the other end of the hydrogen mass flowmeter is connected to the intake pressure regulating valve, the other end of the intake pressure regulating valve is connected to the intake flow regulating valve, the other end of the intake flow regulating valve is connected to the explosion-proof test cover, and the explosion-proof test cover is respectively connected to the vacuum pump to be tested and the absolute vacuum gauge.

[0009] Preferably, a positive pressure gauge is provided between the total pressure regulating valve and the total flow switching ball valve.

[0010] Preferably, the hydrogen buffer tank is connected to a hydrogen gas source.

[0011] Preferably, the dedicated hydrogen laboratory is provided with an explosion-proof electrical structure, a hydrogen concentration detection device, a hydrogen leakage alarm device, an emergency exhaust fan and an exhaust gas emission device.

[0012] A method for measuring a hydrogen volume rate measurement system comprises the following steps: Step S1, preparation before measurement; Step S2: measuring and obtaining the rate.

[0013] The step S1, preparation before measurement, includes: In step S11, all valves are opened, hydrogen is not supplied, and the vacuum pump to be tested is started to evacuate the entire system to a vacuum state, ensuring that the oxygen concentration in the system is below 0.1%. Then, all outlet valves of the hydrogen buffer tank are closed, and the hydrogen source is opened to fill the hydrogen buffer tank with high-pressure hydrogen first. Sufficient hydrogen is provided, and the pressure in the hydrogen buffer tank is observed by a positive pressure gauge to ensure that it does not exceed 10 bar to ensure safety.

[0014] The step S2, measuring and obtaining the rate, includes: Step S21: The total outlet pressure is gradually increased from 1.5 bar to 5 bar by the total pressure regulating valve according to different measuring points, and the total flow switch ball valve is opened to provide a stable and sufficient gas source; In step S22, the intake flow rate Q is obtained through the hydrogen mass flow meter, and the pump port pressure P1 is obtained through the absolute pressure gauge. Before the hydrogen is passed, the absolute pressure gauge measures the base pressure Pb, and then the volume rate under the pump port pressure is calculated using the formula Qv=Q / (P1-Pb).

[0015] Compared with existing technologies, the present invention offers the following advantages: This hydrogen volume rate measurement system and method solves the problems of high-pressure interference with hydrogen source test results, interruptions in the test process after gas supply from cylinders or gas stations through pipelines, and inaccurate hydrogen flow and pressure measurements. By changing the measurement medium and testing hydrogen volume rate, this system fills a gap in existing testing methods. It can accurately test the vacuum pump's hydrogen extraction capacity, making it more accurate and convenient for end-users to select and determine the suitability of vacuum pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 Schematic diagram of a hydrogen volume rate measurement system according to the present invention; Figure 2 This is a schematic diagram of the internal layout of the dedicated hydrogen laboratory of the present invention; Figure 3 Schematic diagram of a measurement method of a hydrogen volume rate measurement system according to the present invention; Figure 4 A detailed diagram of step S11 of the measurement method of the hydrogen volume rate measurement system of the present invention; Figure 5 FIG. 4 is a detailed diagram of step S21 of the measurement method of the hydrogen volume rate measurement system of the present invention.

[0017] In the figure: 1. Special hydrogen laboratory; 2. Explosion-proof electrical structure; 3. Hydrogen concentration detection device; 4. Hydrogen leakage alarm device; 5. Emergency exhaust fan; 6. Tail gas emission device; 101. Hydrogen gas source; 102. Hydrogen buffer tank; 103. Total pressure regulating valve; 104. Positive pressure gauge; 105. Total flow switching ball valve; 106. Hydrogen mass flow meter; 107. Inlet pressure regulating valve; 108. Inlet flow regulating valve; 109. Explosion-proof test cover; 110. Vacuum pump to be tested; 111. Absolute vacuum gauge. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1-2A hydrogen volume rate measurement system is provided in a dedicated hydrogen laboratory 1, comprising a hydrogen buffer tank 102, a total pressure regulating valve 103, a total flow switching ball valve 105, a hydrogen mass flow meter 106, an intake pressure regulating valve 107, an intake flow regulating valve 108, an explosion-proof test cover 109, a vacuum pump to be tested 110, and an absolute vacuum gauge 111; Specifically, hydrogen buffer tank 102 is connected to hydrogen source 101. The outlet of hydrogen buffer tank 102 is connected to total pressure regulating valve 103, the other end of which is connected to total flow switching ball valve 105. A positive pressure gauge 104 is disposed between total pressure regulating valve 103 and total flow switching ball valve 105. The other end of total flow switching ball valve 105 is connected to hydrogen mass flow meter 106, the other end of which is connected to intake pressure regulating valve 107, the other end of which is connected to intake flow regulating valve 108, the other end of which is connected to explosion-proof test cover 109, which is respectively connected to a vacuum pump to be tested 110 and an absolute vacuum gauge 111.

[0020] During use, open all valves, stop supplying hydrogen, and start the vacuum pump 110 to evacuate the entire system, ensuring the oxygen concentration within the system is below 0.1%. Then, close all outlet valves in the hydrogen buffer tank 102 and open the hydrogen source 101 to fill the hydrogen buffer tank 102 with high-pressure hydrogen. Ensure sufficient hydrogen is supplied and use the positive pressure gauge 104 to ensure the pressure within the hydrogen buffer tank 102 does not exceed 10 bar to ensure safety. Use the total pressure regulating valve 103 to gradually increase the total outlet pressure from 1.5 bar to 5 bar, depending on the measurement point. Open the total flow rate switch ball valve 105 to provide a stable and sufficient gas source, and calculate the volumetric rate result based on the vacuum pump under test.

[0021] Specifically, the hydrogen mass flowmeter 106 needs to adjust the total pressure regulating valve 103 as required so that the pressure difference between the front end pressure and the outlet end pressure meets the working requirements, and the inlet pressure regulating valve 107 needs to ensure that the inlet pressure is 101325Pa to simulate the air state and gas flow state.

[0022] Specifically, the dedicated hydrogen laboratory 1 is equipped with an explosion-proof electrical structure 2, a hydrogen concentration detection device 3, a hydrogen leak alarm device 4, an emergency exhaust fan 5, and an exhaust gas emission device 6. The power supply for the vacuum pump to be tested, lighting, vacuum gauges, flow meters and other equipment in the laboratory is replaced by the explosion-proof electrical structure 2. The characteristic is that they are all explosion-proof versions and will not generate sparks and cause explosions. The hydrogen concentration detection device 3 in the laboratory is arranged on the roof. If the hydrogen concentration is detected to be greater than 4% (the explosion point), it will activate the hydrogen leak alarm device 4 to alert the experimenter and activate the emergency exhaust fan 5 to remove the leaked hydrogen. In addition, the hydrogen from the vacuum pump 110 to be tested will be discharged to a height of more than 6 meters through the exhaust gas emission device. Hydrogen itself is non-toxic and harmless and can be discharged directly into the air without open flames. The above are all internal laboratory safety devices, ensuring the safety of the system of the present invention.

[0023] See also Figure 3-5 , a measurement method of a hydrogen volume rate measurement system, comprising the following steps: Step S1, preparation before measurement. It includes: In step S11, open the valve, do not supply hydrogen, start the vacuum pump 110 to be tested, evacuate the entire system to a vacuum state, and ensure that the oxygen concentration in the system is below 0.1%; then close all the outlet valves of the hydrogen buffer tank 102, open the hydrogen source 101, and fill the hydrogen buffer tank 102 with high-pressure hydrogen first. Sufficient hydrogen is provided, and the positive pressure gauge 104 is used to observe that the pressure in the hydrogen buffer tank 102 does not exceed 10 bar to ensure safety.

[0024] Step S2: measuring the rate. This includes: Step S21: The total outlet pressure is gradually increased from 1.5 bar to 5 bar by the total pressure regulating valve 103 according to different measuring points, and the total flow switch ball valve 105 is opened to provide a stable and sufficient gas source; In step S22, the hydrogen mass flowmeter 106 obtains the intake flow rate Q, and the absolute pressure gauge 111 obtains the pump inlet pressure P1. Before hydrogen is introduced, the absolute pressure gauge 111 measures the base pressure Pb. The volumetric velocity at this pump inlet pressure can then be calculated using the formula Qv = Q / (P1 - Pb).

[0025] This hydrogen volumetric rate measurement system and method uses a fixed high pressure to provide sufficient gas, supplemented by an adapted pipeline diameter and secondary pressure reduction, to ensure both sufficient gas volume before entering the pump and stable inlet pressure during measurement. While maintaining the basic dimensions required by national standards, the test vessel is converted into a positive pressure vessel, enabling both volumetric rate measurement and safety. Furthermore, the selection of an appropriate hydrogen mass flowmeter 106 and absolute vacuum gauge 111 accurately measures hydrogen pressure and flow, enabling calculation of the hydrogen pumping rate.

[0026] In addition, taking into account the flammable and explosive properties of hydrogen, an additional hydrogen laboratory was built, and designs were made for hydrogen concentration detection, emergency exhaust, exhaust emissions, and indoor electrical explosion-proofing to ensure the safety of the testing process.

[0027] This hydrogen volume rate measurement system and method addresses issues such as high pressure at the hydrogen source interfering with test results, interruptions in the gas volume test after supply from cylinders or gas stations through pipelines, and inaccurate hydrogen flow and pressure measurements. By changing the measurement medium and testing hydrogen volume rate, this method fills a gap in existing testing methods. It can accurately test a vacuum pump's hydrogen extraction capacity, making it more accurate and convenient for applications to select and determine the suitability of vacuum pumps.

[0028] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A hydrogen volume rate measurement system, arranged in a dedicated hydrogen laboratory (1), characterized in that: It includes a hydrogen buffer tank (102), a total pressure regulating valve (103), a total flow switching ball valve (105), a hydrogen mass flow meter (106), an intake pressure regulating valve (107), an intake flow regulating valve (108), an explosion-proof test cover (109), a vacuum pump to be tested (110), and an absolute vacuum gauge (111); The outlet of the hydrogen buffer tank (102) is connected to the total pressure regulating valve (103), the other end of the total pressure regulating valve (103) is connected to the total flow switch ball valve (105), the other end of the total flow switch ball valve (105) is connected to the hydrogen mass flow meter (106), the other end of the hydrogen mass flow meter (106) is connected to the intake pressure regulating valve (107), the other end of the intake pressure regulating valve (107) is connected to the intake flow regulating valve (108), the other end of the intake flow regulating valve (108) is connected to the explosion-proof test cover (109), and the explosion-proof test cover (109) is respectively connected to the vacuum pump to be tested (110) and the absolute vacuum gauge (111).

2. The hydrogen volume rate measurement system according to claim 1, characterized in that: A positive pressure gauge (104) is provided between the total pressure regulating valve (103) and the total flow switching ball valve (105).

3. The hydrogen volume rate measurement system according to claim 1, characterized in that: The hydrogen buffer tank (102) is connected to a hydrogen source (101).

4. The hydrogen volume rate measurement system according to claim 1, characterized in that: The dedicated hydrogen laboratory (1) is provided with an explosion-proof electrical structure (2), a hydrogen concentration detection device (3), a hydrogen leakage alarm device (4), an emergency exhaust fan (5) and an exhaust gas emission device (6).

5. A measurement method based on the hydrogen volume rate measurement system according to claim 1, characterized in that: The following steps are involved: Step S1, preparation before measurement; Step S2: measuring and obtaining the rate.

6. The method for measuring the hydrogen volume rate according to claim 5, wherein: The step S1, preparation before measurement, includes: In step S11, all valves are opened, hydrogen is not supplied, and the vacuum pump (110) to be tested is started to evacuate the entire system to a vacuum state, ensuring that the oxygen concentration in the system is below 0.1%; then all outlet valves of the hydrogen buffer tank (102) are closed, and the hydrogen source (101) is opened to allow high-pressure hydrogen to first fill the hydrogen buffer tank (102), provide sufficient hydrogen, and observe with a positive pressure gauge (104) that the pressure in the hydrogen buffer tank (102) does not exceed 10 bar to ensure safety.

7. The method for measuring the hydrogen volume rate according to claim 5, wherein: The step S2, measuring and obtaining the rate, includes: Step S21, the total outlet pressure is gradually increased from 1.5 bar to 5 bar according to different measuring points through the total pressure regulating valve (103), and the total flow switch ball valve (105) is opened to provide a stable and sufficient gas source; In step S22, the intake flow rate Q is obtained by the hydrogen mass flow meter (106), and the pump port pressure P1 is obtained by the absolute pressure gauge (111). Before the hydrogen is passed, the absolute pressure gauge (111) can measure the base pressure Pb, and then the volume rate under the pump port pressure is calculated by the formula Qv=Q / (P1-Pb).

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