A hydrogen circulation pump and ejector performance test system

Abstract

The application discloses a hydrogen circulating pump and ejector performance test system, which comprises a gas supply unit, a working condition control unit, a measurement and collection unit, an ejector and a hydrogen circulating pump. The gas supply unit is connected with the working condition control unit. The working condition control unit is connected with a high-pressure inlet pipeline, a low-pressure inlet pipeline and a hydrogen pump inlet pipeline through an opening adjusting valve. The high-pressure inlet pipeline, the low-pressure inlet pipeline and the hydrogen pump inlet pipeline are respectively connected with a high-pressure inlet, a low-pressure inlet and a hydrogen pump inlet of the ejector. An ejector exhaust pipeline of the ejector and a hydrogen pump exhaust pipeline of the hydrogen pump are connected with an exhaust buffer tank. The exhaust buffer tank is connected with a main loop through an exhaust pipeline. The main loop is externally connected with a main vent pipeline. The measurement and collection unit is connected with the high-pressure inlet pipeline, the low-pressure inlet pipeline, the hydrogen pump inlet pipeline, the ejector exhaust pipeline and the hydrogen pump exhaust pipeline. The application has the effects of reducing cost, saving resources and protecting the environment.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a hydrogen circulation pump and ejector performance testing system. Background Technology

[0002] Hydrogen fuel cells, with their advantages of being clean, operating at low temperatures, starting up quickly, and having high specific power, can meet the application needs of transportation, stationary power sources, and other fields, and have now become the mainstream technology route for fuel cells both domestically and internationally.

[0003] As a crucial component of the hydrogen supply system for hydrogen fuel cells, the hydrogen recirculation system's role is to pressurize unreacted hydrogen at the stack outlet and return it to the stack inlet, where it merges with the inlet reactant gas before entering the stack. The hydrogen recirculation system serves two purposes: firstly, it carries some water from the reactant exhaust gas into the stack, acting as a humidifier; secondly, it increases the hydrogen flow velocity within the fuel cell anode channel, preventing anode flooding; and thirdly, it improves hydrogen utilization. Currently, commonly used technologies include hydrogen recirculation pumps and ejectors. Hydrogen recirculation pumps are simple to control, have a wide flow adjustment range, and possess rapid flow regulation capabilities, meeting the different operating parameters and rapid response requirements of the fuel cell stack. Ejectors offer advantages such as simple structure, small size, and no parasitic power loss, but their operating range is limited. The performance of the hydrogen recirculation pump and ejector directly affects the fuel cell stack's performance. Accurately understanding the performance of these components requires obtaining their performance curves through testing, providing a reference for selecting the appropriate hydrogen supply system for the fuel cell stack.

[0004] Currently, performance testing systems for hydrogen circulation pumps and ejectors are generally built separately. This not only increases investment and leads to redundant construction, but also makes it difficult to accurately simulate various actual operating conditions of hydrogen circulation pumps. In particular, it is difficult to achieve complex inlet conditions for a mixture of hydrogen, nitrogen, and water vapor at different temperatures and pressures. Consequently, the performance parameters of the hydrogen circulation pumps and ejectors tested in experiments differ from the actual requirements of fuel cells, making it difficult to achieve efficient and stable operation of the entire unit after installation in a fuel cell. Therefore, it is essential to develop a system with performance testing capabilities for hydrogen circulation pumps and ejectors and to conduct experiments on them. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by this patent application is how to provide a performance testing system for hydrogen circulation pumps and ejectors, which can evaluate the performance status of the tested hydrogen circulation pumps and ejectors, provide test data support for the design and optimization of hydrogen circulation pumps and ejectors, and provide a basis for the selection of hydrogen supply systems.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A hydrogen circulation pump and ejector performance testing system includes a gas supply unit, an operating condition control unit, a measurement and acquisition unit, an ejector, and a hydrogen circulation pump.

[0008] The gas supply unit includes a hydrogen supply unit and a nitrogen supply unit;

[0009] The hydrogen supply unit and nitrogen supply unit are connected to the operating condition control unit. The operating condition control unit is connected to the high-pressure inlet pipeline, the low-pressure inlet pipeline, and the hydrogen pump inlet pipeline via an opening adjustment valve. The high-pressure inlet pipeline, the low-pressure inlet pipeline, and the hydrogen pump inlet pipeline are respectively connected to the high-pressure inlet, the low-pressure inlet, and the hydrogen pump inlet of the ejector. The ejector exhaust pipeline of the ejector and the hydrogen pump exhaust pipeline are connected to the exhaust buffer tank. Ball valves are respectively installed on the ejector exhaust pipeline and the hydrogen pump exhaust pipeline. The exhaust buffer tank is connected to the main circuit via an exhaust pipeline. The main circuit is connected to a main vent pipeline, and the exhaust pipeline is connected to the main vent pipeline and is equipped with a ball valve. A gas composition detection unit is installed on the main circuit.

[0010] The measurement and acquisition unit is connected to the high-pressure intake pipeline, the low-pressure intake pipeline, the hydrogen pump intake pipeline, the ejector exhaust pipeline, and the hydrogen pump exhaust pipeline; the hydrogen pump exhaust pipeline is connected to the exhaust pipeline via a gas detection pipeline, on which two ball valves and a gas oil content detector are installed, with the gas oil content detector located between the two ball valves.

[0011] The hydrogen supply unit includes a hydrogen cylinder, a first pressure reducing valve group, and a first ball valve connected via a hydrogen inlet pipeline; the nitrogen supply unit includes a nitrogen cylinder, a second pressure reducing valve group, and a second ball valve connected via a nitrogen inlet pipeline; the hydrogen inlet pipeline and the nitrogen inlet pipeline merge to form an inlet pipeline; it also includes a first bypass connected to the nitrogen supply unit, on which a first regulating valve is provided, the first regulating valve being located between the second pressure reducing valve group and the second ball valve; the inlet pipeline and the first bypass are connected to the main circuit, and an opening regulating valve is provided between the inlet pipeline and the first bypass.

[0012] The measurement and acquisition unit includes temperature and pressure sensors installed on the high-pressure intake pipe, low-pressure intake pipe, hydrogen pump intake pipe, ejector exhaust pipe, and hydrogen pump exhaust pipe, as well as humidity sensors installed on the low-pressure intake pipe and hydrogen pump intake pipe, and flow sensors installed on the high-pressure intake pipe, low-pressure intake pipe, and hydrogen pump intake pipe.

[0013] The operating condition control unit includes a pressure control unit and a temperature and humidity control unit;

[0014] The pressure control unit includes a high-pressure intake buffer tank and a low-pressure intake buffer tank. The inlets of the high-pressure intake buffer tank and the low-pressure intake buffer tank are respectively connected to the main circuit, and a ball valve is installed on the main circuit. The outlet of the high-pressure intake buffer tank is connected to the high-pressure intake pipeline. The outlet of the low-pressure intake buffer tank is connected to the ejector low-pressure intake pipeline and the hydrogen pump intake pipeline. An opening adjustment valve is installed between the outlet of the high-pressure intake buffer tank and the outlet of the low-pressure intake buffer tank, and at the outlet of the low-pressure intake buffer tank.

[0015] The temperature and humidity control unit includes a heating and humidification module and a gas-liquid separator. The heating and humidification module is connected to a low-pressure air intake buffer tank and is equipped with a ball valve. The heating and humidification module is connected to the gas-liquid separator. The gas-liquid separator is connected to the outlet of the low-pressure air intake buffer tank through a second regulating valve. The unit also includes a second bypass. The second bypass is connected to the outlets of the heating and humidification module and the gas-liquid separator, and a third regulating valve is installed on the second bypass.

[0016] The high-pressure air intake buffer tank, the low-pressure air intake buffer tank, the heating and humidification module, the gas-liquid separator, and the exhaust buffer tank are all connected to external drainage pipes, and ball valves are installed on the drainage pipes.

[0017] The gas composition detection unit includes a gas composition detector. The inlet and outlet of the gas composition detector are connected to a third ball valve and a fourth ball valve. A fifth ball valve is provided between the third ball valve and the fourth ball valve. The fifth ball valve is connected to the main venting pipeline. The inlet of the gas composition detector is connected to the low-pressure gas inlet pipeline and the hydrogen pump gas inlet pipeline through a detection pipeline, and a sixth ball valve is installed on the detection pipeline.

[0018] The system also includes a safety protection unit, which comprises a safety valve, a flame arrester, a check valve, a combustible gas detector, an audible and visual alarm, a grounding protection device, and a solenoid valve installed between the first pressure reducing valve group and the first ball valve on the hydrogen inlet pipeline. The flame arrester and check valve are installed on the main vent pipeline, the safety valve is installed on the main circuit, the grounding protection device grounds the test system via a cable, and the combustible gas detector is placed in the laboratory where the test system is located. The combustible gas detector is connected to the audible and visual alarm, the solenoid valve, and the electrical control system.

[0019] The hydrogen pump inlet pipe and the inlet pipe are both equipped with pipe filters.

[0020] In summary, this hydrogen circulation pump and ejector performance testing system, through the coordinated use of its various subsystems, can actively adjust and control the hydrogen circulation pump and ejector for hydrogen fuel cells under different gas compositions, temperatures, pressures, and humidity conditions. This more accurately simulates the real operating environment of the hydrogen circulation pump and ejector in hydrogen fuel cells, thereby better adapting them to hydrogen fuel cells.

[0021] This test system can also test the performance of hydrogen circulation pumps and ejectors in parallel operation, providing valuable data for various applications of hydrogen supply systems in fuel cell stacks. Based on the test data obtained from the testing methods, the performance of the designed hydrogen circulation pumps and ejectors can be effectively evaluated, providing support for their optimized design and a reference for equipment selection in the fuel cell stack hydrogen supply subsystem. In addition to performance testing of the hydrogen circulation pumps and ejectors, it can also serve as a reliability test bench for durability and start-stop testing of the hydrogen circulation pumps. This test system can also meet the testing requirements of other gaseous working fluid pumps.

[0022] In addition, the closed-loop operation mode allows for the recycling of test gases. Especially during ejector testing, there is no need to add a low-pressure gas source, which helps reduce testing costs and effectively saves resources and protects the environment. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a hydrogen circulation pump and ejector performance testing system according to the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. In the description of the present invention, it should be understood that directional terms such as "upper," "lower," "top," and "bottom" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are used only for the convenience of describing the present invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of the present invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0025] A hydrogen circulation pump and ejector performance testing system includes a gas supply unit, an operating condition control unit, a measurement and acquisition unit, an ejector, and a hydrogen circulation pump.

[0026] The gas supply unit includes a hydrogen supply unit and a nitrogen supply unit;

[0027] The hydrogen supply unit and nitrogen supply unit are connected to the operating condition control unit. The operating condition control unit is connected to the high-pressure inlet pipeline, the low-pressure inlet pipeline, and the hydrogen pump inlet pipeline via an opening adjustment valve. The high-pressure inlet pipeline, the low-pressure inlet pipeline, and the hydrogen pump inlet pipeline are respectively connected to the high-pressure inlet, the low-pressure inlet, and the hydrogen pump inlet of the ejector. The ejector exhaust pipeline of the ejector and the hydrogen pump exhaust pipeline are connected to the exhaust buffer tank. Ball valves are respectively installed on the ejector exhaust pipeline and the hydrogen pump exhaust pipeline. The exhaust buffer tank is connected to the main circuit via an exhaust pipeline. The main circuit is connected to a main vent pipeline, and the exhaust pipeline is connected to the main vent pipeline and is equipped with a ball valve. A gas composition detection unit is installed on the main circuit.

[0028] The measurement and acquisition unit is connected to the high-pressure intake pipeline, the low-pressure intake pipeline, the hydrogen pump intake pipeline, the ejector exhaust pipeline, and the hydrogen pump exhaust pipeline; the hydrogen pump exhaust pipeline is connected to the exhaust pipeline via a gas detection pipeline, on which two ball valves and a gas oil content detector are installed, with the gas oil content detector located between the two ball valves.

[0029] The hydrogen supply unit includes a hydrogen cylinder, a first pressure reducing valve group, and a first ball valve connected via a hydrogen inlet pipeline; the nitrogen supply unit includes a nitrogen cylinder, a second pressure reducing valve group, and a second ball valve connected via a nitrogen inlet pipeline; the hydrogen inlet pipeline and the nitrogen inlet pipeline merge to form an inlet pipeline; it also includes a first bypass connected to the nitrogen supply unit, on which a first regulating valve is provided, the first regulating valve being located between the second pressure reducing valve group and the second ball valve; the inlet pipeline and the first bypass are connected to the main circuit, and an opening regulating valve is provided between the inlet pipeline and the first bypass.

[0030] The measurement and acquisition unit includes temperature and pressure sensors installed on the high-pressure intake pipe, low-pressure intake pipe, hydrogen pump intake pipe, ejector exhaust pipe, and hydrogen pump exhaust pipe, as well as humidity sensors installed on the low-pressure intake pipe and hydrogen pump intake pipe, and flow sensors installed on the high-pressure intake pipe, low-pressure intake pipe, and hydrogen pump intake pipe.

[0031] The operating condition control unit includes a pressure control unit and a temperature and humidity control unit;

[0032] The pressure control unit includes a high-pressure intake buffer tank and a low-pressure intake buffer tank. The inlets of the high-pressure intake buffer tank and the low-pressure intake buffer tank are respectively connected to the main circuit, and a ball valve is installed on the main circuit. The outlet of the high-pressure intake buffer tank is connected to the high-pressure intake pipeline. The outlet of the low-pressure intake buffer tank is connected to the ejector low-pressure intake pipeline and the hydrogen pump intake pipeline. An opening adjustment valve is installed between the outlet of the high-pressure intake buffer tank and the outlet of the low-pressure intake buffer tank, and at the outlet of the low-pressure intake buffer tank.

[0033] The temperature and humidity control unit includes a heating and humidification module and a gas-liquid separator. The heating and humidification module is connected to a low-pressure air intake buffer tank and is equipped with a ball valve. The heating and humidification module is connected to the gas-liquid separator. The gas-liquid separator is connected to the outlet of the low-pressure air intake buffer tank through a second regulating valve. The unit also includes a second bypass. The second bypass is connected to the outlets of the heating and humidification module and the gas-liquid separator, and a third regulating valve is installed on the second bypass.

[0034] The high-pressure air intake buffer tank, the low-pressure air intake buffer tank, the heating and humidification module, the gas-liquid separator, and the exhaust buffer tank are all connected to external drainage pipes, and ball valves are installed on the drainage pipes.

[0035] The gas composition detection unit includes a gas composition detector. The inlet and outlet of the gas composition detector are connected to a third ball valve and a fourth ball valve. A fifth ball valve is provided between the third ball valve and the fourth ball valve. The fifth ball valve is connected to the main venting pipeline. The inlet of the gas composition detector is connected to the low-pressure gas inlet pipeline and the hydrogen pump gas inlet pipeline through a detection pipeline, and a sixth ball valve is installed on the detection pipeline.

[0036] The system also includes a safety protection unit, which comprises a safety valve, a flame arrester, a check valve, a combustible gas detector, an audible and visual alarm, a grounding protection device, and a solenoid valve installed between the first pressure reducing valve group and the first ball valve on the hydrogen inlet pipeline. The flame arrester and check valve are installed on the main vent pipeline, the safety valve is installed on the main circuit, the grounding protection device grounds the test system via a cable, and the combustible gas detector is placed in the laboratory where the test system is located. The combustible gas detector is connected to the audible and visual alarm, the solenoid valve, and the electrical control system.

[0037] The hydrogen pump inlet pipe and the inlet pipe are both equipped with pipe filters.

[0038] In practice, see the attached diagram in the instruction manual. Figure 1 :

[0039] The entire performance testing system can be divided into a gas supply unit, a working condition control unit, a measurement and acquisition unit, a safety protection unit, an ejector, and a hydrogen circulation pump, according to their functions. It also includes a pipeline unit and auxiliary units.

[0040] By relying on the reasonable coordination between the various units, closed-loop tests of hydrogen circulation, performance tests of ejectors, and parallel tests of hydrogen circulation pumps and ejectors can be carried out to achieve test and evaluation of different hydrogen supply systems.

[0041] like Figure 1 As shown, the gas supply unit includes hydrogen and nitrogen gas sources. Hydrogen source 1 and nitrogen source 2 are supplied using standard high-pressure gas cylinders and connected to the test system through inlet pipes and connectors. The gas supply unit consists of hydrogen cylinder 1 and nitrogen cylinder 2, pressure reducing valve groups 3 and 4, solenoid valve 5, ball valves 7 and 8, regulating valve 9, pipeline filter, and corresponding piping. Gases from the hydrogen and nitrogen sources can flow unidirectionally from the gas cylinders to the test system after passing through the corresponding valves. Pressure reducing valve groups 3 and 4 can regulate the gas pressure entering the test system. Solenoid valve 5 automatically closes after detecting a hydrogen leak, promptly cutting off the hydrogen supply. Hydrogen enters the test system through pressure reducing valve group 3, solenoid valve 5, and ball valve 7; nitrogen enters the system through pressure reducing valve group 4 and ball valve 8. The air in the system is purged before and after the test. During mixed gas tests, nitrogen can enter the system through regulating valve 9. The pipeline filter prevents small particulate matter from entering the test system.

[0042] The piping unit provides a pathway for gas flow and also provides a location for the installation of measuring equipment. The piping unit mainly consists of pipes and valves.

[0043] (1) Most of the piping in the pipeline unit is made of 316L stainless steel rigid pipe, including: the inlet pipe connecting the hydrogen and nitrogen sources into the main circuit; the main circuit pipe forming the circulation between the gas source and the vent pipe in open flow and in closed flow; the vent pipe connecting the main circuit pipe to the atmosphere; and the drain pipe discharging liquid water condensed from humid gas. Since the test pieces need to be frequently disassembled and replaced at the inlet and outlet connections of the hydrogen circulation pump and ejector, flexible metal hoses 41, 47, 51, 58, and 65 with PTFE lining and braided stainless steel outer sheath are used for connection. The test pieces and system use chuck-type quick couplings. A rubber-plastic insulation layer is laid on the outer surface of the pipeline to reduce heat loss during heating and prevent burns. Pipeline filter 57 filters out small particulate impurities in the gas, preventing them from entering the compression chamber of the hydrogen circulation pump and damaging the rotor.

[0044] (3) Valves include ball valves, regulating valves, safety valves, check valves, and solenoid valves. Ball valves are mainly used to cut off, distribute, and change the direction of medium flow; regulating valves are mainly used to regulate gas pressure and flow; safety valves are mainly used to prevent system overpressure; check valves are mainly used to block backflow of the medium; and solenoid valves are used to cut off the hydrogen source in emergencies. Figure 1 As shown, the specific functions of each valve are as follows:

[0045] Pressure reducing valve group 3, 4: The pressure reducing valve group is a two-stage pressure reducing valve, which reduces the high pressure gas in the gas cylinder to the pressure required for the test.

[0046] Solenoid valve 5: Used as an emergency shut-off valve. When the hydrogen safety alarm sounds, the feedback signal from the alarm is input to solenoid valve 5 to shut off the hydrogen source in an emergency.

[0047] Safety valves 6 and 30: Overpressure protection devices in the circuit system. The safety valves automatically open to relieve pressure when overpressure occurs.

[0048] Check valve 32: Prevents atmospheric air from flowing back into the piping system when the system is purged.

[0049] Ball valves 7 and 8: Control the flow of hydrogen or nitrogen into the test system.

[0050] Regulating valve 9: During the ejector mixed gas test, nitrogen is added to the system according to the detection results of the gas composition detector 36.

[0051] Regulating valve 10 and ball valve 11: These control the gas flow direction. Gas can enter the circulation system through regulating valve 10. Closing ball valve 17 allows purging of the pipeline between ball valve 10 and ball valve 31. During the circulation test, hydrogen can be replenished to the system through regulating valve 10. Gas enters the high-pressure buffer tank through ball valve 11.

[0052] Ball valves 13, 16, 21, 26, and 68: drain condensate from the buffer tank, heating and humidifying module, and steam-water separator.

[0053] Regulating valve 14: During the mixed gas circulation test of the hydrogen circulation pump, high-pressure gas with the required gas composition is prepared in advance in the high-pressure intake buffer tank. When the operating conditions of the circulation pump change and the intake pressure is insufficient, gas is replenished to the system through valve 14.

[0054] Ball valves 17 and 18: Ball valve 17 controls the gas to enter the low-pressure intake buffer tank 15; ball valve 18 controls the gas to enter the heating and humidification module 20.

[0055] Ball valve 19: Water can be added to the heating and humidification module 20 through ball valve 19 to ensure the required liquid level for humidification.

[0056] Regulating valves 22, 23, and 24: Close regulating valve 22 and open ball valve 18 to conduct a moisture test; close ball valve 18 and open regulating valve 22 to conduct a dry gas test; adjusting regulating valves 22, 23, and 24 can control the temperature and humidity entering the hydrogen circulation pump 62 and ejector 44.

[0057] Ball valves 27, 34, and 35: Ball valve 27 is a sampling control valve for measuring the gas composition entering the hydrogen circulation pump and ejector during the open test of hydrogen circulation pump 62, the single test of ejector 44, and the parallel test of ejector 44 and circulation pump 62. Ball valve 34 is a sampling control valve for detecting gas composition during system purging and hydrogen filling. Ball valve 35 is the exhaust valve of gas composition analyzer 36.

[0058] Ball valve 28: Valve 28 must be closed during system purging.

[0059] Ball valve 31: System venting and system purge exhaust valve.

[0060] Regulating valves 37 and 38: When conducting relevant tests on ejector 44, adjust the flow rate of the test gas circulation and the flow rate of the venting.

[0061] Regulating valve 39: Regulates the flow rate and pressure of high-pressure gas entering the high-pressure inlet of ejector 44.

[0062] Ball valves 48 and 66, regulating valves 49 and 55: Select either an ejector test or a circulating pump test for individual units, or a parallel test of both. Close valves 48 and 49 and open valves 55 and 66 for a single hydrogen circulating pump test 62; close valves 55 and 66 and open valves 48 and 49 for a single ejector test 44; open all four valves and adjust the valve openings for a parallel test of the ejector and circulating pump.

[0063] Ball valves 69 and 71: Ball valves 69 and 71 are sampling valves for the gas oil content detector. During the test of the circulating pump 62, the oil content of the exhaust gas of the circulating pump can be detected by the gas oil content detector 70 to evaluate the dynamic sealing performance of the circulating pump.

[0064] The regulating valve can be a manual regulating valve or an electric regulating valve.

[0065] The operating condition control unit includes a pressure control unit and a temperature and humidity control unit;

[0066] The gas buffer tanks are divided into a high-pressure inlet buffer tank 12, a low-pressure inlet buffer tank 15, and an exhaust buffer tank 67. They ensure stable gas flow within the test system, reduce fluid pressure fluctuations, and also function as gas storage tanks in closed-loop tests. During hydrogen circulation pump 62 mixed gas tests, the high-pressure inlet buffer tank 12 can serve as a high-pressure mixed gas storage tank. When the circulation pump's operating conditions change and an increase in inlet pressure is required, supplementary gas can be added and pressurized via regulating valves 14 or 10. The gas buffer tanks are made of stainless steel, with inlet and outlet pipes arranged at 90°, bottom inlet and top outlet. Drain valves 13, 16, and 68 are located at the bottom of the buffer tanks, and each buffer tank is equipped with a pointer-type pressure gauge.

[0067] The operating condition control unit consists of valves, a heating and humidifying module 20, and a steam-water separator 25 in the aforementioned piping system. By combining and properly opening and closing the valves, the gas composition, temperature, pressure, and flow rate can be regulated. The heating and humidifying module 20 heats the water to the required test temperature and maintains a stable temperature; the heating temperature is adjustable. The test gas enters the heating and humidifying module and overflows from small holes at the bottom, exchanging heat with the hot water through convection, while simultaneously carrying away some water vapor, thus transforming the test gas into a high-temperature, high-humidity gas. The heating and humidifying module is a bubble-type humidifier, consisting of a tank, liquid inlet, liquid outlet, air inlet, air outlet, level gauge, electric heater, and temperature sensor. The electric heater's power is adjustable, and PID control is performed based on the temperature detected by the sensor and the set temperature to ensure a constant water temperature. The electric heater is installed at the bottom of the heating and humidifying module, and the entire unit adopts an explosion-proof design. The vapor-water separator 25 is a baffle type, consisting of a tank, baffle, air inlet, exhaust outlet and liquid outlet. It can adjust the temperature and humidity of the test gas by using the heating and humidification module 20, the vapor-water separator 25 and the operating valves 22, 23 and 24.

[0068] The measurement and acquisition unit inputs sensor signals into the data acquisition system, where the acquisition module connects to a computer to display the measurement results in real time. The measurement and acquisition system consists of temperature sensors 42, 46, 53, 60, and 63; pressure sensors 43, 45, 54, 61, and 63; humidity sensors 52 and 59; flow sensors 40, 50, and 56; a gas composition detector 36; a gas oil content detector 70; a power analyzer; a data acquisition card; and a computer. Each sensor is either a voltage-type or current-type sensor and is connected to the data acquisition card. The gas composition detector 36 is a hydrogen-nitrogen-oxygen composite gas detector, capable of real-time online detection of gas composition and content in the experimental system. The gas oil content detector 70 can real-time online detection of organic hydrocarbon content in the gas. The data acquisition card receives and converts the acquired signals. Combined with the sensors, gas detectors, power analyzer, and computer, the system enables real-time data display, acquisition, and storage of the measurement and acquisition results.

[0069] The safety protection unit consists of safety valves 6 and 30, check valve 32, flame arrester 33, combustible gas detector, audible and visual alarm, solenoid valve 5, and grounding protection 29. Safety valves 6 and 30 automatically open to release gas after overpressure in the test system; check valve 32 prevents backflow of gas during system purging; flame arrester 33 prevents flame from flowing back into the test system in case of accidental hydrogen combustion; the combustible gas detector monitors the hydrogen concentration in the laboratory where the test system is located, and when the hydrogen concentration in the air reaches the flammability limit, the connected audible and visual alarm sounds an alarm; solenoid valve 5 is a normally open solenoid valve and is linked to the alarm. When the audible and visual alarm sounds, the solenoid valve automatically closes, cutting off the hydrogen source and stopping the gas supply to the system. Grounding protection ensures the entire test system is grounded via cables to prevent static electricity and sparks.

[0070] The auxiliary unit includes the power supply and distribution system and the bench support for the performance testing system equipment. The power supply and distribution system provides and distributes the corresponding power to and controls the various electrical devices in the performance testing system of this invention, and mainly consists of explosion-proof distribution cabinets, explosion-proof adjustable DC power supplies, etc. The bench support is mainly composed of 40*40 aluminum profiles and their accessories, which, after assembly as required, can provide support and fixation for the above-mentioned systems and equipment. II. Detailed Implementation

[0072] 2.1 System leak detection and purging

[0073] Connect the hydrogen circulation pump 62 and ejector 44 correctly to the test system, open the nitrogen pressure reducing valve 4 and ball valve 8, close the hydrogen pipeline valve 7, and fill the system with nitrogen. Perform pressure holding and leak detection on the system as required. Subsequent tests can only be carried out when the system leakage rate meets the relevant requirements; otherwise, the leak point should be dealt with first.

[0074] Using a segmented purging principle, valves 10, 14, 28, 38, 49, and 66 are closed, while valves 11, 39, 48, and 31 are opened to purge the high-pressure intake buffer tank 12, the high-pressure inlet of ejector 44, the mixed gas exhaust port, the exhaust buffer tank 67, and the exhaust pipeline. Valves 34 and 35 are opened, and the gas composition is detected by the gas composition detector 36. When the oxygen content is below 0.5%, the purging of this section of the pipeline is complete. Then, valves 11, 18, and 55 are closed, while valves 10, 17, 22, and 49 are opened to purge the low-pressure intake buffer tank and the low-pressure intake pipeline of ejector 44. After purging this section, valves 22, 49, and 48 are closed, while valves 18, 55, and 66 are opened to purge the heating and humidification module 20, the gas-liquid separator 25 and its bypass, the intake and exhaust pipelines of the hydrogen circulation pump 62, and the subsequent pipelines of the exhaust buffer tank 67. Finally, close valves 17 and 37, open valve 28, and purge the remaining pipeline.

[0075] The hydrogen purging process is the same as the nitrogen purging process. Close valve 8 and open valve 7. Adjust the pressure reducing valve group 3 to the specified pressure. Operate the corresponding valves according to the nitrogen purging process. The hydrogen purging is completed when the gas composition detector 36 detects that the hydrogen content is higher than 99%.

[0076] Before all tests begin, nitrogen and hydrogen purging should be performed to ensure that the gas composition in the system meets the test requirements; after the test, nitrogen purging should be performed to replace the hydrogen in the system with nitrogen.

[0077] 2.2. Preparation of Mixed Gas

[0078] Hydrogen circulation pump mixed gas closed-loop test mixed gas preparation: After hydrogen purging, close valves 39, 49, and 49 to isolate the ejector system, close exhaust valve 31 and gas composition detector inlet valve 34, and open valves 11 and 14 to charge the system with hydrogen at a certain pressure; calculate the required nitrogen pressure based on the required hydrogen-nitrogen composition ratio and Dalton's law of partial pressures. After replenishment, turn on hydrogen circulation pump 62 to ensure thorough and uniform gas mixing, open valve 34 to detect the mixed gas composition and make fine adjustments, close valve 34 and gas composition detector after mixing the gas, and then close valves 10, 11, and 14.

[0079] Preparation of mixed gas for ejector testing or parallel testing of both: Since the ejector-assisted test is essentially a semi-open test, it requires continuous replenishment of high-pressure hydrogen and low-pressure nitrogen, and the removal of excess gas. Therefore, a real-time replenishment method is adopted. After the system is purged with hydrogen, open valves 27 and 35, close valve 34, and monitor the gas composition entering the low-pressure inlet of the ejector and the inlet of the hydrogen circulation pump in real time. Close valves 8, 10, and 14, open valves 7 and 11, and adjust valves 39, 49, 48, 55, 66, 37, and 38 to start the test. Based on the detected gas composition and the required gas composition, adjust valve 9 to automatically inject a certain amount of nitrogen into the system to achieve the required concentration of gas components for the test.

[0080] 2.3. Temperature and humidity control of the test gas

[0081] Open valves 18 and 24, and close valves 22 and 23. Adjust the opening of valve 22 to regulate the temperature based on the humidity and temperature measured by the low-pressure inlet humidity sensor 52 and temperature sensor 53 of the ejector or the humidity sensor 59 and temperature sensor 60 of the circulating pump. Adjust the opening of valve 23 to regulate the humidity.

[0082] 2.4. Closed-loop test of hydrogen circulation pump

[0083] After replacing the gas in the system with the required gas according to the above purging procedure, close valves 10, 11, 14, 48, and 49 to isolate the ejector pipeline system during the closed-loop test of the hydrogen circulation pump. At the same time, close valves 22 and 23 and exhaust valves 31 and 38, open valves 17, 18, 24, 55, and 66, turn on the heating and humidification module, and set the heating temperature. Since there is heat dissipation in the pipeline, the set temperature should be higher than the required temperature of the hydrogen circulation pump inlet. Start the hydrogen circulation pump 62 to conduct the closed-loop test of the circulation pump heating and humidification inlet. Under hydrogen conditions, different pressures can be adjusted via valve 37. Adjusting the pressure rise will cause changes in the inlet and outlet pressures. At this time, it is necessary to simultaneously adjust the replenishment valve 10, the pressure rise regulating valve 37, and the exhaust valve 38 to stabilize the inlet and outlet pressures. Under mixed gas conditions, a certain pressure of high-pressure mixed gas is pre-stored in the high-pressure inlet buffer tank 12. At this time, valves 10, 14, and 39 are in the closed state. When the operating conditions change, gas can be replenished through valve 10 or 14, valve 37 adjusts the inlet and outlet pressures, and valve 38 exhausts gas. After the mixed gas in the high-pressure inlet buffer tank 12 is used up, mixed gas needs to be prepared again. First, the remaining gas composition is measured, and then the gas pressure to be replenished is calculated according to the current pressure and Dalton's law of partial pressures. The specific preparation method is the same as described above. At a certain speed, after the measurement data of the temperature sensors 60 and 64, pressure sensors 61 and 63, humidity sensor 59, and flow meter 56 at the inlet and outlet of the circulating pump stabilize, the data is recorded, and then the adjustment for the next operating condition is performed.

[0084] 2.5. Single ejector test

[0085] Before the test, the system was purged with nitrogen and hydrogen as required in section 2.1. Valves 55 and 66 were closed to isolate the circulating pump system, and valves 10 and 14 were closed to isolate the high-pressure and low-pressure intake gases. Valves 11, 39, 48, 37, 28, 17, 18, and 24 were opened, and valves 8, 9, 22, 23, 31, 34, and 38 were closed. The heating and humidification module 20 was turned on. When conducting the hydrogen test, the pressure of the pressure reducing valve 3 was adjusted, valve 7 was opened, and valves 39, 37, and 38 were adjusted to regulate the intake pressure and flow rate, as well as the exhaust gas flow rate, so that the high-pressure intake pressure, low-pressure intake pressure, and exhaust pressure reached the required test values. Valves 22, 23, and 24 were adjusted to ensure that the low-pressure intake temperature and humidity reached the required test values. When conducting the mixed gas test, adjust the pressure of the nitrogen pressure reducing valve group, open valves 27 and 35, turn on the gas composition detector to measure the gas composition at the ejector inlet in real time, and adjust valve 9 to replenish nitrogen into the system so that the gas composition in the system meets the test requirements. The adjustment methods for ejector inlet and outlet pressure, temperature, and humidity are the same as described in section 2.3 above. After the ejector inlet and outlet temperature, pressure, humidity, and flow rate have stabilized, record the relevant data. Then adjust to the next operating condition.

[0086] 2.6 Parallel test of ejector and hydrogen circulation pump

[0087] Similar to the ejector unit test, valves 10 and 14 are closed to isolate the high-pressure and low-pressure intake gases. Valves 48, 49, 55, and 66 are opened or closed according to the order in which the hydrogen circulation pump and ejector are put into operation. The following explanation uses the circulation pump being put into operation first as an example. Valves 39, 48, and 49 are closed to isolate the ejector. The circulation pump is started according to the hydrogen circulation pump unit test procedure. Then, at the operating point required by the test plan, valve 48 and regulating valves 39 and 49 are opened to put the ejector into the system. Simultaneously, regulating valves 37 and 38 are used to maintain a relatively stable circulation flow and venting flow. Regulating valves 49 and 55 distribute the flow into the low-pressure inlet of the ejector and the hydrogen circulation pump. Regulating valves 48 and 66 can also be used to bring the intake and exhaust pressures to the values ​​required for the test. The temperature and humidity of the intake gas are adjusted as described in section 2.3 above. The mixed gas test is the same as the ejector unit test.

[0088] III. Test Methods

[0089] 3.1 Experimental Preparation

[0090] (1) Inspect the test bench and power supply system to eliminate the risk of loosening of each interface.

[0091] (2) Turn on the main power switch, adjust the power switches of the electrical control system to turn on the control power and instrument power while turning off the power power, turn on the measuring and testing equipment and adjust it to normal working condition.

[0092] (3) Turn on the power switch and replace the gas in the test system with hydrogen or a hydrogen-nitrogen mixture according to the methods described in 2.1 and 2.2.

[0093] (4) Turn on the heating and humidification module to preheat the water to the required temperature. The preparation work is complete.

[0094] 3.2 Test Implementation

[0095] (1) Operate according to the methods described in 2.4 to 2.6 above, depending on the different test requirements.

[0096] (2) Adjust the test conditions according to the gas composition, inlet and outlet pressure, temperature and humidity adjustment methods described above, based on the test content.

[0097] (3) After the test conditions are adjusted, the host computer controls the speed of the hydrogen circulation pump. When the hydrogen circulation pump reaches a stable or quasi-stable operating state, the test parameters are collected and stored. The acquisition system can collect parameters such as the inlet flow rate, inlet and outlet pressure, temperature and humidity, and gas composition of the hydrogen circulation pump and ejector. The power analyzer can measure parameters such as the power, voltage, and current input and output of the hydrogen circulation pump controller.

[0098] (4) Design the test condition table according to the principle of single variable, and repeat steps (2) and (3) to carry out performance tests of hydrogen circulation pump and ejector under different working conditions.

[0099] 3.3 End of Experiment

[0100] (1) Turn off the heating and humidification module 20 and other operating condition adjustment equipment.

[0101] (2) Replace the gas in the system with nitrogen according to the method in 2.2; then open the drain pipe and close it after draining all the liquid water.

[0102] (3) Turn off the power supply to each measuring device, turn off the power, control and instrument switches, and turn off the main power switch.

[0103] (4) Check the test system circuit and each piece of equipment to ensure they are in good condition, tidy up the test bench, and complete the test.

[0104] Finally, it should be noted that those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A hydrogen circulation pump and ejector performance test system, characterized by, The gas supply unit, the working condition control unit, the measurement and collection unit, the ejector and the hydrogen circulation pump are included. The gas supply unit includes a hydrogen supply unit and a nitrogen supply unit. The hydrogen supply unit and the nitrogen supply unit are connected with the working condition control unit, the working condition control unit is connected with the high-pressure inlet pipeline, the low-pressure inlet pipeline and the hydrogen pump inlet pipeline through the opening adjusting valve, the high-pressure inlet pipeline, the low-pressure inlet pipeline and the hydrogen pump inlet pipeline are connected with the high-pressure inlet, the low-pressure inlet and the hydrogen pump inlet of the ejector respectively, the ejector exhaust pipeline and the hydrogen pump exhaust pipeline of the ejector are connected with the exhaust buffer tank, the ball valve is arranged on the ejector exhaust pipeline and the hydrogen pump exhaust pipeline respectively, the exhaust buffer tank is connected with the main loop through the exhaust pipeline, the main loop is connected with the main vent pipeline, the exhaust pipeline and the main vent pipeline are connected and the ball valve is arranged, the gas component detection unit is installed on the main loop. The measurement and collection unit is connected with the high-pressure inlet pipeline, the low-pressure inlet pipeline, the hydrogen pump inlet pipeline, the ejector exhaust pipeline and the hydrogen pump exhaust pipeline, the hydrogen pump exhaust pipeline is connected with the exhaust pipeline through the gas detection pipeline, the two ball valves and the gas oil content detector are installed on the gas detection pipeline, the gas oil content detector is located between the two ball valves, the pipeline filter is installed on the hydrogen pump inlet pipeline and the inlet pipeline. The working condition control unit includes the gas pressure control unit and the temperature and humidity control unit. The gas pressure control unit includes the high-pressure inlet buffer tank and the low-pressure inlet buffer tank, the inlet of the high-pressure inlet buffer tank and the low-pressure inlet buffer tank is connected with the main loop and the ball valve is arranged on the main loop, the outlet of the high-pressure inlet buffer tank is connected with the high-pressure inlet pipeline, the outlet of the low-pressure inlet buffer tank is connected with the low-pressure inlet pipeline and the hydrogen pump inlet pipeline, the opening adjusting valve is arranged between the outlet of the high-pressure inlet buffer tank and the outlet of the low-pressure inlet buffer tank and the outlet of the low-pressure inlet buffer tank. The temperature and humidity control unit includes the heating and humidifying module and the gas-liquid separator, the heating and humidifying module is connected with the low-pressure inlet buffer tank and the ball valve is arranged, the heating and humidifying module is connected with the gas-liquid separator, the gas-liquid separator is connected with the outlet of the low-pressure inlet buffer tank through the second adjusting valve, the second bypass is connected with the heating and humidifying module and the outlet of the gas-liquid separator and the third adjusting valve is installed on the second bypass.

2. The hydrogen circulator pump and ejector performance test system of claim 1, wherein, The hydrogen supply unit includes the hydrogen cylinder, the first pressure reducing valve group and the first ball valve connected through the hydrogen inlet pipeline, the nitrogen supply unit includes the nitrogen cylinder, the second pressure reducing valve group and the second ball valve connected through the nitrogen inlet pipeline, the hydrogen inlet pipeline and the nitrogen inlet pipeline are merged to form the inlet pipeline, the first bypass connected with the nitrogen supply unit is further included, the first adjusting valve is arranged on the first bypass, the first adjusting valve is located between the second pressure reducing valve group and the second ball valve, the inlet pipeline and the first bypass are connected with the main loop and the opening adjusting valve is arranged between the inlet pipeline and the first bypass.

3. The hydrogen circulator pump and ejector performance test system of claim 2, wherein, The measurement and collection unit comprises temperature sensors and pressure sensors arranged on the high-pressure intake pipeline, the low-pressure intake pipeline, the hydrogen pump intake pipeline, the ejector exhaust pipeline and the hydrogen pump exhaust pipeline, humidity sensors arranged on the low-pressure intake pipeline and the hydrogen pump intake pipeline, and flow sensors arranged on the high-pressure intake pipeline, the low-pressure intake pipeline and the hydrogen pump intake pipeline.

4. The hydrogen circulator pump and ejector performance test system of claim 1, wherein, The high-pressure intake buffer tank, the low-pressure intake buffer tank, the heating and humidifying module, the gas-liquid separator and the exhaust buffer tank are all externally connected with liquid discharge pipelines, and ball valves are installed on the liquid discharge pipelines.

5. The hydrogen circulator pump and ejector performance test system of claim 1, wherein, The gas component detection unit comprises a gas component detector, third and fourth ball valves connected to the inlet and outlet of the gas component detector, a fifth ball valve arranged between the third and fourth ball valves, the fifth ball valve being connected to a main venting pipeline, and a sixth ball valve installed on a detection pipeline connecting the inlet of the gas component detector to the low-pressure intake pipeline and the hydrogen pump intake pipeline.

6. The hydrogen circulator pump and ejector performance test system of claim 1, wherein, The safety protection unit comprises a safety valve, a flame arrester, a check valve, a combustible gas detector, an audible and visual alarm, a grounding protection, and an electromagnetic valve arranged between a first pressure reducing valve group and a first ball valve on the hydrogen intake pipeline; the flame arrester and the check valve are installed on the main venting pipeline, the safety valve is installed on the main circuit, the grounding protection makes the test system grounded through a cable, the combustible gas detector is placed in a laboratory where the test system is located, and the combustible gas detector is connected to the audible and visual alarm, the electromagnetic valve and an electrical control system.

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