Hydrogen subsystem of fuel cell testing system

Abstract

The utility model discloses a hydrogen subsystem of a fuel cell test system, which comprises a hydrogen supply assembly, a hydrogen circulation assembly and a gas discharge assembly, the hydrogen supply assembly comprises a hydrogen supply pipeline, and a first flowmeter, an ejector, a humidifier and a heater which are sequentially arranged on the hydrogen supply pipeline; the hydrogen supply pipeline is connected with an anode inlet of the fuel cell; the gas discharge assembly comprises a gas discharge pipeline, and the gas discharge pipeline is connected with an anode outlet of the fuel cell; the hydrogen circulation assembly comprises a hydrogen circulation pipeline and a gas-liquid separator installed on the hydrogen circulation pipeline, the two ends of the hydrogen circulation pipeline are connected with the ejector and the gas exhaust pipeline respectively, and the hydrogen circulation pipeline is externally connected with a heating and heat preservation device. The device has the beneficial effects that the hydrogen consumption of the test system is reduced, the nitrogen concentration in the hydrogen entering the reactor is reduced, and the test system is simplified.

Description

Technical Field

[0001] The utility model relates to the field of fuel cells, in particular to a hydrogen subsystem for a fuel cell testing system. Background Art

[0002] Proton exchange membrane fuel cells are an efficient and clean energy conversion device with broad application prospects. Hydrogen is the fuel of fuel cells. In order to achieve the ideal power generation of fuel cells, excessive hydrogen and air are usually introduced. If the excess hydrogen in the fuel cell test system directly enters the tail exhaust, a large amount of hydrogen will be wasted in the high-power stack test system. Therefore, for energy saving and safety reasons, it is necessary to reuse the excess hydrogen.

[0003] The fuel cell hydrogen subsystem is a hydrogen supply, humidification, heating and circulation device. The hydrogen subsystem of the existing fuel cell test system often does not contain the hydrogen circulation function. The hydrogen circulation unit involved mostly adopts the method of hydrogen circulation pump, which mainly has the following problems: On the one hand, the excess hydrogen in the fuel cell test system often directly enters the tail exhaust, which will cause a large amount of hydrogen waste in the high-power stack test system. On the one hand, in the existing test system containing the hydrogen circulation function, the hydrogen circulation pump is often used. The hydrogen circulation pump has a high operating load under a large flow rate, and has a limited service life and high cost, which greatly increases the cost of the test system. On the one hand, the flow control in the hydrogen supply of the existing fuel cell test system is a mass flow controller, which is expensive. On the other hand, the existing hydrogen circulation device often adopts an external form, that is, the hydrogen circulation pump is connected to the fuel cell and the hydrogen supply pipeline outside the original test bench, which will increase the space of the test system and reduce the appearance. When testing high-power fuel cells, multiple hydrogen circulation pumps are required to be connected in parallel, which further increases the volume of the test system. It will increase the space of the test system and reduce the appearance.

[0004] For example, publication number CN116314943A discloses an external hydrogen circulation device for a fuel cell test bench, which specifically includes: a fuel cell stack; a hydrogen circulation pump; a control cabinet; a hydrogen gas source; and a water-gas separation component. The recycling of hydrogen is achieved by means of an external hydrogen circulation pump, and the emission of nitrogen is not considered. In actual operation, a small amount of nitrogen will leak from the air side to the hydrogen side, which will cause the hydrogen concentration on the hydrogen side to decrease during long-term operation, thereby reducing the output performance of the fuel cell.

[0005] For example, publication number CN215418247U discloses a fuel cell system with a proportional valve, including a hydrogen source, a pressure reducing valve, a hydrogen spray, a system controller, an ejector, a fuel cell stack, and a gas-liquid separator. The fuel cell system of this invention combines a switch valve, a proportional valve, and a chamber in an ejector and performs an integrated design. However, this utility model does not monitor the flow of hydrogen, which poses certain risks. At the same time, nitrogen removal is not considered.

[0006] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Utility Model Content

[0007] The technical problem to be solved by the utility model is: how to solve the problem that the circulation of the current hydrogen subsystem is achieved by a circulation pump, which cannot operate for a long time under high humidity and high temperature, has a limited service life, and increases the volume of the test system.

[0008] The utility model solves the above technical problems through the following technical means:

[0009] The hydrogen subsystem of the fuel cell test system includes a hydrogen supply component, a hydrogen circulation component, and a gas exhaust component. The hydrogen supply component includes a hydrogen supply pipeline and a first flow meter, an ejector, a humidifier, and a heater installed on the hydrogen supply pipeline in sequence, and the hydrogen supply pipeline is connected to the anode inlet of the fuel cell; the gas exhaust component includes a gas exhaust pipeline, and the gas exhaust pipeline is connected to the anode outlet of the fuel cell; the hydrogen circulation component includes a hydrogen circulation pipeline and a gas-liquid separator installed on the hydrogen circulation pipeline, and both ends of the hydrogen circulation pipeline are respectively connected to the ejector and the gas exhaust pipeline, and the hydrogen circulation pipeline is externally connected to a heating and heat preservation device.

[0010] In the utility model, hydrogen enters the fuel cell through the hydrogen supply assembly, and then enters the gas exhaust assembly. Part of the hydrogen re-enters the hydrogen supply assembly through the hydrogen circulation assembly after gas-liquid separation and heating and heat preservation to achieve reuse, thereby reducing hydrogen waste. In the utility model, on the one hand, the ejector is used to realize the hydrogen circulation of the fuel cell test system, thereby reducing the consumption of hydrogen by the test system. On the other hand, the ejector proportional valve, nitrogen exhaust valve assembly, proportional valve and the first flow meter at the front end can realize the control and detection of the hydrogen flow into the ejector. The nitrogen exhaust valve regularly discharges the nitrogen in the hydrogen discharged, thereby reducing the nitrogen concentration in the hydrogen entering the stack. On the other hand, the ejector is small in size, and compared with the small size of the hydrogen circulation pump, it is better integrated in the test system. At the same time, the ejector with a proportional valve can replace the mass flow controller, thereby simplifying the test system.

[0011] Preferably, the hydrogen supply assembly further comprises a first valve, a first pressure reducing valve, a second valve, a first flow meter, and a first pressure sensor which are sequentially installed on the hydrogen supply pipeline, and the first pressure sensor is located at the inlet end of the ejector.

[0012] Preferably, a second pressure sensor and a first temperature sensor are also installed on the hydrogen supply pipeline between the ejector and the humidifier.

[0013] Preferably, a third pressure sensor and a second temperature sensor are also installed on the hydrogen supply pipeline between the heater and the fuel cell.

[0014] Preferably, a third valve and a back pressure valve are sequentially installed on the gas exhaust pipeline, and the third valve is located at the rear end of the connection between the hydrogen circulation pipeline and the gas exhaust pipeline.

[0015] Preferably, the heating and heat-insulating device comprises a heating belt and heat-insulating cotton; the outer surface of the hydrogen circulation pipeline is connected to the heating belt, and the outside of the heating belt is wrapped with heat-insulating cotton.

[0016] The heating and insulation device can maintain the inlet temperature of hydrogen and reduce the load of the heater.

[0017] Preferably, the inlet end of the gas-liquid separator is also connected to a fourth valve, and the outlet end of the gas-liquid separator is also connected to a second flow meter, a sixth valve, a fourth pressure sensor and a third temperature sensor in sequence.

[0018] Preferably, a first liquid level sensor and a second liquid level sensor are installed at intervals along the height direction on the side of the gas-liquid separator, and the bottom of the gas-liquid separator is connected to a drainage pipe, and a fifth valve is installed on the drainage pipe.

[0019] Preferably, it also includes a nitrogen purge assembly, which includes a nitrogen pipeline and a seventh valve, a second pressure reducing valve, an eighth valve, a first flow controller, and a ninth valve sequentially connected to the nitrogen pipeline.

[0020] Nitrogen purging is mainly performed before hydrogen is turned on and after hydrogen is turned off, mainly to prevent hydrogen from mixing with air in the pipeline and to improve safety.

[0021] Preferably, it also includes a second flow controller and a tenth valve, the tenth valve is installed on the hydrogen supply pipeline and located at the front end of the ejector; the two ends of the second flow controller are respectively connected to the hydrogen supply pipeline and the nitrogen pipeline, and the connection between the second flow controller and the hydrogen supply pipeline is located at the front end of the tenth valve, and the connection between the second flow controller and the nitrogen pipeline is located at the rear end of the ninth valve.

[0022] The second flow controller is a high-pressure flow controller that can more accurately control the flow of hydrogen into the ejector. At this time, the ejector may not have a proportional valve, and the tenth valve is in a closed state. The addition of the first flow controller and the second flow controller enables the system to have a precise gas mixing function, making the function of the test system more complete.

[0023] The advantages of the utility model are:

[0024] In the utility model, hydrogen enters the fuel cell through the hydrogen supply assembly, and then enters the gas exhaust assembly. Part of the hydrogen re-enters the hydrogen supply assembly through the hydrogen circulation assembly after gas-liquid separation and heating and heat preservation to achieve reuse, thereby reducing hydrogen waste. In the utility model, on the one hand, the ejector is used to realize the hydrogen circulation of the fuel cell test system, thereby reducing the consumption of hydrogen by the test system. On the other hand, the ejector proportional valve, nitrogen exhaust valve assembly, proportional valve and the first flow meter at the front end can realize the control and detection of the hydrogen flow into the ejector. The nitrogen exhaust valve regularly discharges the nitrogen in the hydrogen discharged, thereby reducing the nitrogen concentration in the hydrogen entering the stack. On the other hand, the ejector is small in size, and compared with the small size of the hydrogen circulation pump, it is better integrated in the test system. At the same time, the ejector with a proportional valve can replace the mass flow controller, thereby simplifying the test system.

[0025] The heating and insulation device can maintain the inlet temperature of hydrogen and reduce the load of the heater.

[0026] Nitrogen purging is mainly performed before hydrogen is turned on and after hydrogen is turned off, mainly to prevent hydrogen from mixing with air in the pipeline and to improve safety.

[0027] The second flow controller is a high-pressure flow controller that can more accurately control the flow of hydrogen into the ejector. At this time, the ejector may not have a proportional valve, and the tenth valve is in a closed state. The addition of the first flow controller and the second flow controller enables the system to have a precise gas mixing function, making the function of the test system more complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a connection diagram of the hydrogen subsystem of the fuel cell test system in the first embodiment of the utility model;

[0029] Figure 2 This is a schematic diagram of the working process of the hydrogen subsystem of the fuel cell test system in the first embodiment of the utility model;

[0030] Figure 3 It is a connection diagram of the hydrogen subsystem of the fuel cell test system in the second embodiment of the present utility model;

[0031] Numbers in the figure:

[0032] 100, hydrogen supply assembly; 101, hydrogen supply pipeline; 102, first valve; 103, first pressure reducing valve; 104, second valve; 105, first flow meter; 106, first pressure sensor; 107, ejector; 108, second pressure sensor; 109, first temperature sensor; 110, humidifier; 111, heater; 112, third pressure sensor; 113, second temperature sensor;

[0033] 200, hydrogen circulation component; 201, hydrogen circulation pipeline; 202, fourth valve; 203, gas-liquid separator; 204, second flow meter; 205, sixth valve; 206, fourth pressure sensor; 207, third temperature sensor; 208, heating and heat preservation device; 209, first liquid level sensor; 210, second liquid level sensor; 211, fifth valve;

[0034] 300, gas exhaust component; 301, gas exhaust pipeline; 302, third valve; 303, back pressure valve;

[0035] 400. Fuel cell;

[0036] 500, nitrogen purge assembly; 501, nitrogen pipeline; 502, seventh valve; 503, second pressure reducing valve; 504, eighth valve; 505, first flow controller; 506, ninth valve. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] Embodiment 1:

[0039] like Figure 1 , Figure 2 As shown, the hydrogen subsystem of the fuel cell test system includes a hydrogen supply component 100, a hydrogen circulation component 200, and a gas exhaust component 300. The hydrogen supply component 100 supplies hydrogen to the fuel cell 400, and the hydrogen circulation component 200 processes the hydrogen at the rear end of the fuel cell and re-introduces it into the fuel cell 400 for use. The gas exhaust component 300 is used for exhaust gas discharge.

[0040] The hydrogen supply assembly 100 includes a hydrogen supply pipeline 101 and a first valve 102, a first pressure reducing valve 103, a second valve 104, a first flow meter 105, a first pressure sensor 106, an ejector 107, a second pressure sensor 108, a first temperature sensor 109, a humidifier 110, a heater 111, a third pressure sensor 112, and a second temperature sensor 113 which are sequentially installed on the hydrogen supply pipeline 101. The left end of the hydrogen supply pipeline 101 is a hydrogen source, and the right end is connected to the anode inlet of the fuel cell 400.

[0041] The first pressure sensor 106 is used to monitor and measure the hydrogen pressure of the ejector 107, and a first flowmeter 105 is provided at the front end of the first pressure sensor 106 to monitor and measure the control of the hydrogen flow rate by the proportional valve in the ejector 107 assembly. The first pressure reducing valve 103 is used to control the hydrogen pressure entering the ejector 107. The pressure range is generally 5-20 bar. The second pressure sensor 108 and the first temperature sensor 109 are located at the rear end of the ejector 107 outlet to monitor and measure the hydrogen outlet pressure and temperature of the ejector 107. The humidifier 110 is located after the first temperature sensor 109 to humidify the hydrogen entering the fuel cell 400. The humidifier 110 can be bubbled, sprayed or steam humidified. The heater 111 is located at the rear end of the humidifier 110 and is used for temperature control of hydrogen entering the fuel cell 400. The pipeline between the humidifier 110 and the fuel cell 400 is insulated by a heating belt and a heat preservation cotton to prevent the gas from cooling and the condensation of water vapor, thereby reducing the load of the test system. The front end pipeline of the fuel cell 400 inlet is provided with a third pressure sensor 112 and a second temperature sensor 113 for monitoring and measuring the pressure and temperature of hydrogen before entering the fuel cell 400.

[0042] It should be noted that the ejector 107 includes its components, such as a switch valve, a proportional valve, a pressure sensor, a temperature sensor, a pressure relief valve, a nitrogen exhaust valve, etc.

[0043] The hydrogen circulation assembly 200 includes a hydrogen circulation pipeline 201 and a fourth valve 202, a gas-liquid separator 203, a second flowmeter 204, a sixth valve 205, a fourth pressure sensor 206 and a third temperature sensor 207 installed on the hydrogen circulation pipeline 201. The two ends of the hydrogen circulation pipeline 201 are respectively connected to the ejector 107 and the gas exhaust pipeline 301, and the hydrogen circulation pipeline 201 is externally connected to a heating and heat preservation device 208. The heating and heat preservation device 208 includes a heating belt and heat preservation cotton. The outer surface of the hydrogen circulation pipeline 201 is connected to the heating belt, and the outer surface of the heating belt is wrapped with heat preservation cotton. The heating and heat preservation device 208 can maintain the inlet temperature of hydrogen and reduce the load of the heater 111.

[0044] The first liquid level sensor 209 and the second liquid level sensor 210 are installed at intervals on the side of the gas-liquid separator 203 along the height direction. The water outlet of the gas-liquid separator 203 is located at the bottom of the gas-liquid separator 203. The bottom of the gas-liquid separator 203 is connected to a drainage pipe, and a fifth valve 211 is installed on the drainage pipe.

[0045] The gas-liquid separator 203 is located at the rear end of the outlet of the fuel cell 400 to separate water from the outlet hydrogen. The first liquid level sensor 209 and the second liquid level sensor 210 of the gas-liquid separator 203 are used to monitor and measure the liquid level of water in the gas-liquid separator 203. The fifth valve 211 selects a solenoid valve, a pneumatic valve or an electric valve to form a closed-loop control with the gas-liquid separator 203. When the liquid level reaches the second liquid level sensor 210, the fifth valve 211 is opened to drain water, and when the liquid level reaches the first liquid level sensor 209, the fifth valve 211 is closed to close the drainage.

[0046] The gas outlet of the gas-liquid separator 203 is located at the upper part of the gas-liquid separator 203, and the second flow meter 204 is located at the outlet to monitor the flow rate of hydrogen refluxed from the ejector 107. The fourth pressure sensor 206 and the third temperature sensor 207 are located at the reflux inlet pipe of the ejector 107 to monitor and measure the pressure and temperature of the reflux gas.

[0047] The gas exhaust assembly 300 includes a gas exhaust pipe 301 and a third valve 302 and a back pressure valve 303 installed on the gas exhaust pipe 301. The third valve 302 is located at the rear end of the connection between the hydrogen circulation pipe 201 and the gas exhaust pipe 301. The gas exhaust pipe 301 is connected to the anode outlet of the fuel cell 400.

[0048] In this embodiment, hydrogen enters the fuel cell 400 through the hydrogen supply assembly 100, and then enters the gas discharge assembly 300. Part of the hydrogen re-enters the hydrogen supply assembly 100 after gas-liquid separation and heating and heat preservation by the hydrogen circulation assembly 200, and is reused to reduce hydrogen waste. Specifically, the dry high-pressure hydrogen enters the front end of the first pressure reducing valve 103 through the first valve 102, and the hydrogen enters the ejector 107 through the second valve 104 after decompression. The hydrogen enters the humidifier 110 after being regulated by the ejector 107 and its components. The dry hydrogen is humidified and heated to become saturated humidified hydrogen and enter the heater 111. After the temperature of the heater 111 is regulated, it enters the anode inlet of the fuel cell 400. The hydrogen and water not consumed by the fuel cell 400 enter the gas-liquid separator 203 through the pipeline, the gas and liquid are separated through the gas-liquid separator 203, the liquid water is discharged through the drainage pipe, and the gas circulates to the reflux inlet of the ejector 107 through the second flowmeter 204, completing the circulation of the hydrogen. The nitrogen exhaust valve of the ejector 107 regularly discharges nitrogen to reduce the concentration of nitrogen in the hydrogen subsystem. The opening of the ejector 107 inlet is adjusted according to the flow rate fed back by the first flow meter 105 at the front end of the ejector 107, and the sixth valve 205 in the circulation loop can adjust the pressure of the ejector 107 reflux inlet.

[0049] In this embodiment, on the one hand, the ejector 107 is used to realize the hydrogen circulation of the fuel cell 400 test system, thereby reducing the hydrogen consumption of the test system. On the other hand, the ejector 107 is provided with a proportional valve and a nitrogen exhaust valve assembly. The proportional valve and the first flow meter 105 at the front end can realize the control and detection of the hydrogen flow into the ejector 107. The nitrogen exhaust valve regularly discharges the nitrogen in the injected hydrogen to reduce the nitrogen concentration in the hydrogen entering the stack. On the other hand, the ejector 107 is small in size, and compared with the small size of the hydrogen circulation pump, it is better integrated in the test system. At the same time, the ejector 107 with a proportional valve can replace the mass flow controller to simplify the test system.

[0050] Embodiment 2

[0051] like Figure 3 As shown, the hydrogen subsystem of the fuel cell test system also includes a nitrogen purge assembly 500, which includes a nitrogen pipeline 501 and a seventh valve 502, a second pressure reducing valve 503, an eighth valve 504, a first flow controller 505, and a ninth valve 506 connected to the nitrogen pipeline 501 in sequence.

[0052] The hydrogen subsystem of the fuel cell testing system also includes a second flow controller 507 and a tenth valve 508. The tenth valve 508 is installed on the hydrogen supply pipeline 101 and is located at the front end of the ejector 107. The two ends of the second flow controller 507 are respectively connected to the hydrogen supply pipeline 101 and the nitrogen pipeline 501, and the connection between the second flow controller 507 and the hydrogen supply pipeline 101 is located at the front end of the tenth valve 508, and the connection between the second flow controller 507 and the nitrogen pipeline 501 is located at the rear end of the ninth valve 506.

[0053] The second flow controller 507 is a high-pressure flow controller that can more accurately control the flow of hydrogen into the ejector 107. At this time, the ejector 107 may not have a proportional valve, and the tenth valve 508 is in a closed state.

[0054] The addition of the first flow controller 505 and the second flow controller 507 enables the system to have a precise gas mixing function, making the function of the test system more complete.

[0055] Nitrogen can also be replaced by other inert gases.

[0056] The working process of Example 2 is the same as that of Example 1, mainly with the addition of a nitrogen purge function on the basis of Example 1. The nitrogen purge is mainly performed before the hydrogen is turned on and after the hydrogen is turned off, mainly to prevent the hydrogen from mixing with the air in the pipeline and to improve safety.

[0057] Embodiment 2 can also realize the mixing function of hydrogen and nitrogen. The hydrogen flow rate can be controlled by a mass flow meter, or by a proportional valve in the ejector 107 and a front-end flow meter.

[0058] The above-mentioned Embodiment 1 and Embodiment 2 provide a low-cost and efficient hydrogen subsystem of a fuel cell test system. On the one hand, hydrogen can be recycled in a smaller space, so that the fuel cell stack in the test system can efficiently utilize hydrogen. On the other hand, the test system uses the proportional valve in the ejector 107 to control the hydrogen flow rate, so as to simplify the hydrogen subsystem.

[0059] It should be noted that the ejector 107 may also be a combination of the ejector 107 and a hydrogen circulation pump.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen subsystem of a fuel cell test system, characterized in that: It includes a hydrogen supply component, a hydrogen circulation component, and a gas exhaust component. The hydrogen supply component includes a hydrogen supply pipeline and a first flow meter, an ejector, a humidifier, and a heater installed on the hydrogen supply pipeline in sequence. The hydrogen supply pipeline is connected to the anode inlet of the fuel cell; the gas exhaust component includes a gas exhaust pipeline, and the gas exhaust pipeline is connected to the anode outlet of the fuel cell; the hydrogen circulation component includes a hydrogen circulation pipeline and a gas-liquid separator installed on the hydrogen circulation pipeline, the two ends of the hydrogen circulation pipeline are respectively connected to the ejector and the gas exhaust pipeline, and the hydrogen circulation pipeline is externally connected to a heating and heat preservation device.

2. The hydrogen subsystem of the fuel cell test system according to claim 1, characterized in that: The hydrogen supply assembly also includes a first valve, a first pressure reducing valve, a second valve, a first flow meter, and a first pressure sensor which are sequentially installed on the hydrogen supply pipeline. The first pressure sensor is located at the inlet end of the ejector.

3. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: A second pressure sensor and a first temperature sensor are also installed on the hydrogen supply pipeline between the ejector and the humidifier.

4. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: A third pressure sensor and a second temperature sensor are also installed on the hydrogen supply pipeline between the heater and the fuel cell.

5. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: A third valve and a back pressure valve are sequentially installed on the gas exhaust pipeline, and the third valve is located at the rear end of the connection between the hydrogen circulation pipeline and the gas exhaust pipeline.

6. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: The heating and heat-insulating device comprises a heating belt and heat-insulating cotton. The outer surface of the hydrogen circulation pipeline is connected to the heating belt, and the outside of the heating belt is wrapped with heat-insulating cotton.

7. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: The inlet end of the gas-liquid separator is also connected to the fourth valve, and the outlet end of the gas-liquid separator is also connected to the second flow meter, the sixth valve, the fourth pressure sensor and the third temperature sensor in sequence.

8. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: A first liquid level sensor and a second liquid level sensor are installed at intervals along the height direction on the side of the gas-liquid separator. The bottom of the gas-liquid separator is connected to a drainage pipe, and a fifth valve is installed on the drainage pipe.

9. The hydrogen subsystem of the fuel cell testing system according to claim 1, characterized in that: It also includes a nitrogen purge component, which includes a nitrogen pipeline and a seventh valve, a second pressure reducing valve, an eighth valve, a first flow controller, and a ninth valve connected to the nitrogen pipeline in sequence.

10. The hydrogen subsystem of the fuel cell testing system according to claim 9, characterized in that: It also includes a second flow controller and a tenth valve, wherein the tenth valve is installed on the hydrogen supply pipeline and located at the front end of the ejector; the two ends of the second flow controller are respectively connected to the hydrogen supply pipeline and the nitrogen pipeline, and the connection between the second flow controller and the hydrogen supply pipeline is located at the front end of the tenth valve, and the connection between the second flow controller and the nitrogen pipeline is located at the rear end of the ninth valve.

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