A low pressure crude hydrogen fuel cell test system and test method

Abstract

The application relates to a low-pressure crude hydrogen fuel cell test system and a test method. The system device comprises a hydrogen gas mixing supply module, an air blower supply air module, a cooling circuit and an electronic load control module. The hydrogen gas supply module comprises a nitrogen flow meter and can be used for controlling and mixing hydrogen gas with different concentration ratios. The air supply module adopts a parallel structure, so that the system structure is more simple, the parasitic power is small, and the metering ratio is wide. The water circulation module uses a thermostat instead of a traditional three-way valve on a test platform, can realize large and small circulation working conditions and switching, and can make the stack maintain a small temperature fluctuation. The low-pressure crude hydrogen fuel cell test system can be used for evaluating and testing the sensitivity and system performance of a low-pressure fuel cell stack. The whole test system is more compact in internal structure and design, occupies less space and resources, and is low in system device cost.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and specifically to a testing system and method for low-pressure crude hydrogen fuel cells. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are an energy technology that directly converts the chemical energy in hydrogen and oxygen into electrical energy. They offer advantages such as high efficiency, zero carbon emissions, and low noise. Suitable operating conditions, such as pressure, humidity, and flow rate, are crucial for optimizing fuel cell performance and designing control strategies for the stack system. To explore the optimal operating conditions for fuel cells, especially under "crude hydrogen" and low-pressure systems, it is necessary to use a fuel cell test bench to provide monitoring and control of temperature, pressure, humidity, and air flow rate.

[0003] Currently, fuel cell test benches or test systems mainly consist of the following subsystems: hydrogen supply subsystem, air supply subsystem, hydrothermal management subsystem, and monitoring and control subsystem. The hydrogen subsystem only controls hydrogen flow, humidity, and back pressure, lacking mixing capabilities, making it difficult to test fuel cell performance under "crude hydrogen" conditions. The air subsystem primarily uses centrifugal air compressors, which, while offering advantages such as good sealing, compact structure, low vibration, and high energy conversion efficiency, suffer from significant parasitic power consumption, impacting the overall efficiency and economy of the fuel cell stack system. During operation and testing, it consumes a considerable amount of power, reducing the stack system's energy conversion efficiency and increasing overall operating costs due to its high energy consumption. Furthermore, existing test systems are designed for medium- and high-pressure fuel cell stack systems and lack specific testing capabilities for low-pressure "crude hydrogen" conditions. Summary of the Invention

[0004] To address the problems of existing fuel cell testing systems lacking gas mixing capabilities, making it difficult to test fuel cell performance under "crude hydrogen" conditions, and the presence of significant parasitic power in the air path affecting overall fuel cell efficiency and energy consumption, thus increasing operating costs, this paper provides a testing system and method for low-pressure crude hydrogen fuel cells that is suitable for low-pressure environments, can test fuel cell performance under crude hydrogen conditions, and boasts high overall efficiency and low energy consumption.

[0005] The technical solution adopted by this invention to solve its technical problem is: a test system for a low-pressure crude hydrogen fuel cell, comprising a hydrogen mixing supply module, a blower air supply module, a cooling circuit, an electronic load control module, and a fuel cell. The hydrogen mixing supply module includes a hydrogen branch, a nitrogen branch, and a hydrogen humidification tank; the hydrogen branch and the nitrogen branch are connected in parallel and simultaneously connected to the hydrogen humidification tank, which is then connected to the anode inlet of the fuel cell; the blower air supply module includes a first blower, a second blower, and an air humidification tank, which are separately configured; the first blower and the second blower are connected in parallel and simultaneously connected to the anode inlet of the fuel cell. An air humidifier is connected; the air humidifier is connected to the cathode inlet of the fuel cell; the cooling circuit includes a heater, a water pump, a fan, and a thermostat; the fan is connected in parallel to the cathode inlet and cathode outlet of the fuel cell, the heater is connected in series with the water pump, and the heater is then connected to the cathode inlet of the fuel cell; one side of the fan is connected to the water pump, and the other side of the fan is connected to the thermostat, which is then connected to the cathode outlet of the fuel cell; the electronic load control module is connected in parallel to the anode inlet and anode outlet of the fuel cell; a hydrogen back pressure valve is connected to the anode outlet of the fuel cell, and an air back pressure valve is connected to the cathode outlet of the fuel cell.

[0006] Furthermore, the hydrogen branch includes a hydrogen solenoid valve and a hydrogen flow meter, and the nitrogen branch includes a nitrogen solenoid valve and a nitrogen flow meter. The hydrogen flow meter and the hydrogen solenoid valve are connected in series, and the nitrogen solenoid valve and the nitrogen flow meter are also connected in series.

[0007] Furthermore, a pressure gauge and a thermometer are installed between the hydrogen humidification tank and the anode inlet of the fuel cell.

[0008] Furthermore, a gas-liquid separator and a hydrogen circulation pump are connected in parallel above the anode inlet and anode outlet of the fuel cell. The gas-liquid separator and the hydrogen circulation pump are connected in series, with the gas-liquid separator located near the anode outlet of the fuel cell and the hydrogen circulation pump located near the anode inlet of the fuel cell.

[0009] Furthermore, it also includes a first filter and a second filter, the first filter being connected in series with the first blower, and the second filter being connected in series with the second blower; an air flow meter is installed between the first blower, the second blower, and the air humidification tank.

[0010] Furthermore, a hydrogen solenoid valve is connected in parallel above the hydrogen humidification tank, and an air solenoid valve is connected in parallel above the air humidification tank.

[0011] Furthermore, the cooling circuit also includes a deionizer, which is connected in parallel with the fan. One end of the deionizer is connected to the water pump, and the other end of the deionizer is connected to one of the ports of the thermostat.

[0012] A test method for a low-pressure crude hydrogen fuel cell test system using any one of the above-described methods includes the following steps:

[0013] Step 1: Drive the water pump to circulate water within the cooling circuit;

[0014] Step 2: Purge the system by introducing nitrogen and air separately;

[0015] Step 3: Adjust the water pump speed and control the water flow rate, and adjust the heater temperature to control the temperature of the circulating water;

[0016] Step 4: Stop supplying nitrogen into the fuel cell, introduce hydrogen into the hydrogen humidifier for bubbling humidification, and introduce air into the air humidifier for bubbling humidification. The humidity level (RH) should be 60-100%. An open-circuit voltage should be established in the test system.

[0017] Step 5: Control the opening of the hydrogen back pressure valve and the air back pressure valve, adjust the pressure at the anode inlet of the fuel cell to 60 kPa and the pressure at the cathode inlet to 40 kPa; after the temperature rises to 50°C, turn on the electronic load control module to activate the fuel cell;

[0018] Step Six: Introduce air and hydrogen of different concentrations into the fuel cell to generate electricity and detect the parameters of the power generation process.

[0019] Furthermore, in step two, nitrogen gas is introduced into the system at a rate of 10-20 L / min to purge the system, and air is introduced into the system at a rate of 30-40 L / min to purge the system for 3-5 minutes.

[0020] Furthermore, the anode inlet of the fuel cell is connected to a hydrogen solenoid valve, and the cathode inlet is connected to an air solenoid valve. After the test is completed, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the anode and cathode inlet pressures of the fuel cell are set to 0. When both the anode and cathode inlet pressures of the fuel cell drop to zero, the hydrogen and air solenoid valves are opened to switch to a dry circuit state. Hydrogen continues to flow into the test system while air is stopped from being introduced into the test system. The electronic load control module is kept connected. When the individual cell voltage of the fuel cell stack drops to 0.2 V, the hydrogen flow is shut off, and the electronic load control module is disconnected.

[0021] Compared with the prior art, the testing system for low-pressure crude hydrogen fuel cells proposed in this invention has the following advantages:

[0022] 1. This testing system uses a blower to provide a stable airflow, ensuring a continuous supply of oxidant. Meanwhile, the blower has low operating costs, low parasitic power, and low noise, making it environmentally friendly. Furthermore, the blower's simple structure makes it easy to install and maintain, reducing equipment failure rates and extending its service life.

[0023] 2. The blower generates less heat during operation and does not require an additional water circuit for heat dissipation. The cooling water circuit circulation has been optimized, and its structure is simpler. It is equipped with two blowers to achieve a wider airflow supply.

[0024] 3. The hydrogen supply module has been enhanced with a nitrogen flow meter, which can be used to control and prepare hydrogen with different concentration ratios to study the performance of the fuel cell stack under "crude hydrogen" conditions.

[0025] 4. By using a thermostat instead of the three-way valve on the traditional test bench, large and small cycle operation and switching can be achieved, resulting in a smaller fluctuation in coolant temperature.

[0026] 5. The testing system is designed for testing low-pressure fuel cells. The test pipeline contains parameters for monitoring and controlling temperature, pressure, and hydrogen circulation pumps, enabling sensitivity evaluation of low-pressure fuel cell stacks and testing of hydrogen recycling efficiency.

[0027] 6. The internal structure and design of the entire low-voltage testing system are more compact, occupying less space and resources, making it easy to install and maintain, and especially suitable for applications with strict requirements on space and safety. Attached Figure Description

[0028] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0029] In the accompanying drawings of the instruction manual:

[0030] Figure 1 This is a schematic diagram of a test system for low-pressure crude hydrogen fuel cells according to the present invention.

[0031] The reference numerals used in the above figures are explained as follows:

[0032] 1 is the first filter; 2 is the second filter; 3 is the first blower; 4 is the second blower; 5 is the air flow meter; 6 is the air humidifier tank; 7 is the air solenoid valve; 8 is the water pump; 9 is the fan; 10 is the thermostat; 11 is the deionizer; 12 is the air back pressure valve; 13 is the hydrogen back pressure valve; 14 is the gas-liquid separator; 15 is the hydrogen circulation pump; 16 is the hydrogen solenoid valve; 17 is the hydrogen humidifier tank; 18 is the nitrogen flow meter; 19 is the hydrogen flow meter; 20 is the hydrogen solenoid valve; 21 is the nitrogen solenoid valve; 22 is the electronic load; 23 is the heater. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1 As shown, the present invention provides a testing system for a low-pressure crude hydrogen fuel cell, comprising a hydrogen mixing supply module, a blower air supply module, a cooling circuit, an electronic load control module, and a fuel cell.

[0035] The hydrogen mixing supply module includes a hydrogen branch, a nitrogen branch, and a hydrogen humidification tank 17; the hydrogen branch and the nitrogen branch are connected in parallel and are also connected to the hydrogen humidification tank 17, which is then connected to the anode inlet of the fuel cell.

[0036] The blower air supply module includes a first blower 3, a second blower 4 and an air humidification tank 6, which are separately arranged. The first blower 3 and the second blower 4 are connected in parallel and are also connected to the air humidification tank 6. The air humidification tank 6 is connected to the cathode inlet of the fuel cell.

[0037] The cooling circuit includes a heater 23, a water pump 8, a fan 9, and a thermostat 10; the fan 9 is connected in parallel to the cathode inlet and cathode outlet of the fuel cell; the heater 23 is connected in series with the water pump 8; the heater 23 is then connected to the cathode inlet of the fuel cell; one side of the fan 9 is connected to the water pump 8; the other side of the fan 9 is connected to the thermostat 10; and the thermostat 10 is then connected to the cathode outlet of the fuel cell.

[0038] The electronic load control module is connected in parallel with the anode inlet and anode outlet of the fuel cell; the anode outlet of the fuel cell is connected to a hydrogen back pressure valve 13, and the cathode outlet of the fuel cell is connected to an air back pressure valve 12.

[0039] like Figure 1As shown, the hydrogen branch includes a hydrogen solenoid valve 20 and a hydrogen flow meter 19, which are connected in series. The nitrogen branch includes a nitrogen solenoid valve 21 and a nitrogen flow meter 18, which are connected in series. The hydrogen flow meter 19 and the nitrogen flow meter 18 are connected to the hydrogen humidification tank 17. By opening the hydrogen solenoid valve 20 and the nitrogen solenoid valve 21 respectively, hydrogen of different concentrations, i.e., "crude hydrogen," can be obtained by controlling the corresponding flow meters. The hydrogen of different concentrations then enters... The hydrogen humidification tank 17 humidifies the "crude hydrogen" in a bubbling manner, and the humidified gas enters the anode inlet of the fuel cell. Preferably, a pressure gauge and a thermometer are installed between the hydrogen humidification tank 17 and the anode inlet of the fuel cell to detect the anode inlet pressure and temperature of the fuel cell in real time. A hydrogen solenoid valve 16 is connected in parallel above the hydrogen humidification tank 17. The hydrogen mixing supply module is used to control and prepare hydrogen with different concentration ratios. The hydrogen flow meter and nitrogen flow meter are used together to accurately control the mixing ratio of hydrogen and nitrogen. The nitrogen flow meter can adjust the flow rate to prepare hydrogen of different concentrations for testing needs.

[0040] The anode outlet of the fuel cell is connected to a hydrogen back pressure valve 13. Above the anode inlet and anode outlet of the fuel cell, there is a gas-liquid separator 14 and a hydrogen circulation pump 15 connected in parallel. The gas-liquid separator 14 and the hydrogen circulation pump 15 are connected in series. The gas-liquid separator 14 is located near the anode outlet of the fuel cell, and the hydrogen circulation pump 15 is located near the anode inlet of the fuel cell. By controlling the hydrogen back pressure valve 13, the pressure at the anode inlet of the fuel cell can be increased. At the same time, the unreacted hydrogen discharged from the anode outlet of the fuel cell can enter the gas-liquid separator 14, where liquid water is filtered out. Then, it re-enters the fuel cell with the hydrogen circulation pump 15, thus achieving a high utilization rate of hydrogen.

[0041] The blower air supply module includes a first blower 3, a second blower 4, and an air humidification tank 6, which are separately configured. The first blower 3 is connected in series with a first filter 1, and the second blower 4 is connected in series with a second filter 2. The first blower 3 and the second blower 4 are connected in parallel and simultaneously connected to the air humidification tank 6. The air humidification tank 6 is connected to the cathode inlet of the fuel cell. An air flow meter 5 is installed between the first blower 3, the second blower 4, and the air humidification tank 6. The air flow meter 5 is used to detect the flow rate of air entering the air humidification tank 6 to achieve accurate control. The air passes through the first filter 1 and the second filter 2 to remove impurities, and then enters the first blower 3 and the second filter 4, respectively. In the two blowers 4, the air flows through the flow meter 5, is humidified by the bubbling humidification tank 6, and then enters the cathode chamber of the fuel cell. The cathode outlet of the fuel cell is equipped with an air back pressure valve 12. By controlling the air back pressure valve 12, the pressure at the anode inlet of the fuel cell can be increased, and excess air can be discharged through the air back pressure valve 12. An air solenoid valve 7 is connected in parallel above the air humidification tank 6. The blower air supply module adopts a two-blower parallel structure, which can cover a wider range of flow demand, and multiple blowers can be independently adjusted to adapt to different air supply needs. More preferably, the first blower and the second blower are simultaneously connected to the control unit, which is used to synchronize the working status of the two blowers.

[0042] The cooling path includes a heater 23, a water pump 8, a fan 9, a thermostat 10, and a deionizer 11. The heater 23 is connected in series with the water pump 8, and the fan 9 is connected in parallel with the deionizer 11. The water pump 8 is connected to one end of the fan 9 and one end of the deionizer 11. The heater 23 is located near the cooling inlet of the fuel cell. The other end of the fan 9 is connected to one end of the thermostat 10, and the other end of the deionizer 11 is connected to one end of the thermostat 10. One end of the thermostat 10 is connected to the cooling path outlet of the fuel cell. The fan 9 and the water pump 8 are used for water circulation and heat dissipation. The deionizer is used to remove metal ions deposited inside the fuel cell stack and reduce the conductivity of the coolant.

[0043] The cooling path uses a coolant, such as liquid water, to remove heat generated by the fuel cell, ensuring the fuel cell stack operates within a suitable temperature range. The water pump 8 powers the circulation of the coolant within the fuel cell system; adjusting the pump's speed controls the coolant flow rate, thereby regulating the fuel cell temperature. The thermostat 10 controls the coolant flow path, determining whether it enters the fan 9 for a large-scale cooling loop or bypasses it for a smaller loop; this helps precisely control the fuel cell's operating temperature. The cooling path releases heat absorbed from the fuel cell into the environment, thus lowering the coolant temperature. The cooling path is typically equipped with a fan 9 to enhance heat dissipation. The deionizer 11 removes conductive ions from the coolant, maintaining its insulating properties and preventing unwanted current conduction through the coolant in the fuel cell system. Through the coordinated operation of these components, the entire cooling path effectively manages the fuel cell's operating temperature, ensuring efficient operation and extending its lifespan.

[0044] The cooling circuit uses a thermostat instead of a three-way valve on a traditional test bench to achieve large and small cycle operation and switching, ensuring that the fuel cell stack maintains a small temperature difference fluctuation; the cooling circuit also includes a temperature sensor T3, which monitors the temperature of the fuel cell stack and feeds it back to the control unit.

[0045] The electronic load module is a DC electronic load 22. The two ends of the DC electronic load 22 are connected to the anode inlet and anode outlet of the fuel cell, respectively. The DC electronic load 22 is connected in parallel with the fuel cell. The DC electronic load 22 can perform polarization curve performance testing on the fuel cell by setting power, current, voltage and operating mode, and reading current and voltage data.

[0046] A test method for a low-pressure crude hydrogen fuel cell test system, comprising the following steps:

[0047] Step 1: Drive the water pump to circulate water within the cooling circuit;

[0048] Step 2: Purge the system by introducing nitrogen and air separately;

[0049] Step 3: Adjust the water pump speed and control the water flow rate, and adjust the heater temperature;

[0050] Step 4: Stop supplying nitrogen into the fuel cell, introduce hydrogen into the hydrogen humidifier for bubbling humidification, and introduce air into the air humidifier for bubbling humidification. The humidity level (RH) should be 60-100%. An open-circuit voltage should be established in the test system.

[0051] Step 5: Control the opening of the hydrogen back pressure valve and the air back pressure valve, adjust the pressure at the anode inlet of the fuel cell to 60 kPa and the pressure at the cathode inlet to 40 kPa; after the temperature rises to 50°C, turn on the electronic load control module to activate the fuel cell;

[0052] Step Six: Introduce air and hydrogen of different concentrations into the fuel cell to generate electricity and detect the parameters of the power generation process.

[0053] In step one, the 5kW water-cooled stack is connected to the fuel cell in the test system, and the speed of the water pump is set to allow the water to circulate in the cooling circuit, thereby expelling air bubbles in the cooling circuit and reducing uneven heating.

[0054] In step two, connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 to introduce nitrogen and air into the test system at a rate of 10-20 L / min and 30-40 L / min respectively, and purge for 3-5 minutes.

[0055] In step three, the water flow rate is controlled by reducing the speed of water pump 8, and the temperature of heater 23 is adjusted so that the temperature of circulating water is 60°C.

[0056] In step four, the nitrogen flow meter 18 is set to zero, and the nitrogen solenoid valve 21 is closed to stop the introduction of nitrogen into the test system; the hydrogen solenoid valve 20 is opened and the hydrogen flow rate is set to 20-30 L / min, and the hydrogen is introduced into the hydrogen humidification tank 17. At the same time, air is introduced into the air humidification tank 6 for bubbling humidification. The humidification temperature is RH=60-100%, and the open circuit voltage is established.

[0057] In step five, the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 is controlled to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure of the fuel cell to 40 kPa. When the internal temperature of the fuel cell rises to 50°C, the DC electronic load 22 is turned on, the corresponding metering ratio mode is selected, the control mode of the DC electronic load is switched to the current mode, and then the current is set to 10 A. The load current is applied in 10 A steps to straighten the current value corresponding to the rated power, and each current is held for 3 to 5 minutes. The load is cycled multiple times until the load current and voltage curve coincide, which can be considered as the end of the stack activation.

[0058] In step six: air and hydrogen are introduced into the fuel cell to generate electricity; after activation, the sensitive operating conditions of the fuel cell can be investigated. For example, the effects of fuel cell temperature, inlet pressure, and humidity can be explored. When investigating these operating conditions, a controlled variable method can be used to clarify the impact of each operating condition on fuel cell performance.

[0059] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0060] Example 1:

[0061] This embodiment takes the pure hydrogen performance test process and method of a 5 kW non-humidified water-cooled fuel cell stack as an example. The test implementation process is as follows:

[0062] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0063] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 10 L / min and 30 L / min for 3 minutes.

[0064] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0065] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 20 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=100%. At this time, the open circuit voltage begins to be established.

[0066] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure to 40 kPa respectively. After the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, and switch the control mode of the DC electronic load 22 to the current mode. Then set the current to 10 A, and apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes, and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered complete.

[0067] Step Six: Introduce air and hydrogen of different concentrations into the fuel cell to generate electricity; after activation, the sensitive operating conditions of the fuel cell can be investigated. For example, the effects of fuel cell temperature, inlet pressure, and humidity can be explored. When investigating these operating conditions, a controlled variable method can be used to clarify the impact of each operating condition on fuel cell performance.

[0068] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressures of the anode and cathode of the fuel cell are set to 0. When both the anode and cathode inlet pressures of the fuel cell drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the fuel cell stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0069] Example 2

[0070] This embodiment uses the test process and method for testing the performance of an 8 kW self-humidifying water-cooled fuel cell stack under pure hydrogen as an example. The test implementation process is as follows:

[0071] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0072] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 20 L / min and 40 L / min for 5 minutes.

[0073] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0074] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 30 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=60%. At this time, the open circuit voltage begins to be established.

[0075] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure to 40 kPa respectively. After the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, and switch the control mode of the DC electronic load 22 to the current mode. Then set the current to 10 A, and apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes, and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered complete.

[0076] Step 6: Introduce air and hydrogen of different concentrations into the fuel cell for power generation; open the air solenoid valve 7 in the air circuit, so that the air goes through the dry circuit, the hydrogen is kept in its original state, and reduce the relative humidity of the hydrogen humidification tank to RH=30% to focus on the impact of the relative humidity on the hydrogen side on the performance of the self-humidifying fuel cell.

[0077] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0078] Example 3

[0079] This embodiment uses the test process and method of a 5 kW self-humidifying water-cooled fuel cell stack system under pure hydrogen as an example. The test implementation process is as follows:

[0080] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0081] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 20 L / min and 40 L / min for 5 minutes.

[0082] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0083] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 30 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=60%. At this time, the open circuit voltage begins to be established.

[0084] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure of the fuel cell to 40 kPa respectively. When the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, switch the control mode of the DC electronic load 22 to the current mode, and then set the current to 10 A. Apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered to be completed.

[0085] Step Six: Air and hydrogen of different concentrations are introduced into the fuel cell for power generation; the air solenoid valve 7 in the air circuit is opened, the hydrogen solenoid valve 16 in the hydrogen circuit is opened, and the hydrogen circulation pump 15 is turned on at the same time. Hydrogen, liquid water and water vapor pass through the gas-liquid separator 14, and the hydrogen and water vapor return to the anode inlet pipeline of the fuel cell in the hydrogen circulation pump 15; this working process completely simulates the performance of the fuel cell stack in the system output.

[0086] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0087] Example 4

[0088] This embodiment uses the test process and method of a 5 kW self-humidifying water-cooled fuel cell stack system under pure hydrogen as an example. The test implementation process is as follows:

[0089] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0090] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 10 L / min and 30 L / min for 3 minutes.

[0091] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0092] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 20 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=80%. At this time, the open circuit voltage begins to be established.

[0093] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure of the fuel cell to 40 kPa respectively. When the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, switch the control mode of the DC electronic load 22 to the current mode, and then set the current to 10 A. Apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered to be completed.

[0094] Step Six: Introduce air and hydrogen of different concentrations into the fuel cell to generate electricity; specifically, open the nitrogen solenoid valve 21 and set the nitrogen flow rate to achieve a hydrogen-nitrogen concentration ratio of 90%, and test the sensitive operating condition of 90% hydrogen-nitrogen gas.

[0095] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0096] Example 5

[0097] This embodiment uses the test process and method of a 5 kW self-humidifying water-cooled fuel cell stack system under pure hydrogen as an example. The test implementation process is as follows:

[0098] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0099] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 10 L / min and 30 L / min for 3 minutes.

[0100] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0101] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 20 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=80%. At this time, the open circuit voltage begins to be established.

[0102] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure of the fuel cell to 40 kPa respectively. When the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, switch the control mode of the DC electronic load 22 to the current mode, and then set the current to 10 A. Apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered to be completed.

[0103] Step Six: Introduce air and hydrogen of different concentrations into the fuel cell for power generation; specifically, open the nitrogen solenoid valve 21 and set the nitrogen flow rate to achieve a hydrogen-nitrogen concentration ratio of 75%, and test the sensitive operating condition of 75% hydrogen-nitrogen gas; this operating condition truly simulates the operation of hydrogen and nitrogen gas in the stack of the "ammonia-hydrogen" fuel cell.

[0104] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0105] Example 6

[0106] This embodiment uses the test process and method of a 5 kW self-humidifying water-cooled fuel cell stack system under pure hydrogen as an example. The test implementation process is as follows:

[0107] Step 1: Connect the 5 kW water-cooled reactor to the test system; set the water pump to speed 8 to circulate the water in the water chamber, expel air bubbles from the cooling path, and reduce uneven heating.

[0108] Step 2: Connect the pure hydrogen and nitrogen cylinders, turn on the nitrogen solenoid valve 21, start the first blower 3 and the second blower 4, and control the nitrogen flow meter 18 and the air flow meter 5 respectively to purge the test system with nitrogen and air at a speed of 10 L / min and 30 L / min for 3 minutes.

[0109] Step 3: Reduce the speed of water pump 8 to control the water flow rate, and set the temperature of circulating water heater 23 to 60℃;

[0110] Step 4: Set the nitrogen flow meter 18 to zero and close the nitrogen solenoid valve 21. Open the hydrogen solenoid valve 20 and set the hydrogen flow rate to 20 L / min. Hydrogen and air are humidified by bubbling through the hydrogen humidification tank 17 and the air humidification tank 6 respectively. The humidification temperature is RH=80%. At this time, the open circuit voltage begins to be established.

[0111] Step 5: Control the opening of the air back pressure valve 12 and the hydrogen back pressure valve 13 to control the anode inlet pressure of the fuel cell to 60 kPa and the cathode inlet pressure of the fuel cell to 40 kPa respectively. When the fuel cell temperature rises to 50°C, turn on the DC electronic load 22, select the corresponding metering ratio mode, switch the control mode of the DC electronic load 22 to the current mode, and then set the current to 10 A. Apply the load current in 10 A steps to bring up the current value corresponding to the rated power. Hold each current for 3 to 5 minutes and cycle the load multiple times until the load current and voltage curves coincide. The activation of the fuel cell can be considered to be completed.

[0112] Step Six: Air and hydrogen of different concentrations are introduced into the fuel cell for power generation. Specifically, the air solenoid valve 7 in the air path is opened, and the hydrogen solenoid valve 16 in the hydrogen path is opened. The hydrogen-nitrogen mixture enters the fuel cell stack through the main path. At the same time, the hydrogen circulation pump 15 is turned on. Hydrogen, nitrogen, liquid water, and water vapor pass through the gas-liquid separator 14. The hydrogen, water vapor, and nitrogen return to the anode inlet pipeline of the fuel cell in the hydrogen circulation pump 15. This operating process completely simulates the output performance of the fuel cell stack system under hydrogen and nitrogen conditions.

[0113] After the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve 16 and the air solenoid valve 7 are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The hydrogen flow rate 18 is set to 5-30 L / min, the air flow rate is set to 0 L / min, and the DC electronic load 22 is kept connected. When the individual voltage of the stack drops to 0.2 V, the hydrogen flow is turned off and the DC electronic load 22 is disconnected.

[0114] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A testing system for low-pressure crude hydrogen fuel cells, characterized in that: This includes a hydrogen mixture supply module, a blower air supply module, a cooling circuit, an electronic load control module, and a fuel cell. The hydrogen mixing supply module includes a hydrogen branch, a nitrogen branch, and a hydrogen humidification tank; the hydrogen branch and the nitrogen branch are connected in parallel and are also connected to the hydrogen humidification tank, which is then connected to the anode inlet of the fuel cell; The blower air supply module includes a first blower, a second blower, and an air humidification tank, which are separately arranged. The first blower and the second blower are connected in parallel and are also connected to the air humidification tank. The air humidification tank is connected to the cathode inlet of the fuel cell. The cooling circuit includes a heater, a water pump, a fan, and a thermostat; the fan is connected in parallel to the cathode inlet and cathode outlet of the fuel cell, the heater is connected in series with the water pump, and the heater is then connected to the cathode inlet of the fuel cell; one side of the fan is connected to the water pump, the other side of the fan is connected to the thermostat, and the thermostat is then connected to the cathode outlet of the fuel cell. The electronic load control module is connected in parallel with the anode inlet and anode outlet of the fuel cell; the anode outlet of the fuel cell is connected to a hydrogen back pressure valve, and the cathode outlet of the fuel cell is connected to an air back pressure valve.

2. The testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: The hydrogen branch includes a hydrogen solenoid valve and a hydrogen flow meter, and the nitrogen branch includes a nitrogen solenoid valve and a nitrogen flow meter. The hydrogen flow meter and the hydrogen solenoid valve are connected in series, and the nitrogen solenoid valve and the nitrogen flow meter are connected in series.

3. The testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: A pressure gauge and a thermometer are installed between the hydrogen humidification tank and the anode inlet of the fuel cell.

4. The testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: The fuel cell has a gas-liquid separator and a hydrogen circulation pump connected in parallel above the anode inlet and anode outlet. The gas-liquid separator and the hydrogen circulation pump are connected in series. The gas-liquid separator is located near the anode outlet of the fuel cell, and the hydrogen circulation pump is located near the anode inlet of the fuel cell.

5. A testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: It also includes a first filter and a second filter, the first filter being connected in series with the first blower, and the second filter being connected in series with the second blower; an air flow meter is provided between the first blower, the second blower and the air humidification tank.

6. A testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: A hydrogen solenoid valve is connected in parallel above the hydrogen humidification tank, and an air solenoid valve is connected in parallel above the air humidification tank.

7. A testing system for low-pressure crude hydrogen fuel cells according to claim 1, characterized in that: The cooling circuit also includes a deionizer, which is connected in parallel with the fan. One end of the deionizer is connected to the water pump, and the other end of the deionizer is connected to one of the ports of the thermostat.

8. A test method for a low-pressure crude hydrogen fuel cell test system according to any one of claims 1 to 7, characterized in that: Includes the following steps: Step 1: Drive the water pump to circulate water within the cooling circuit; Step 2: Purge the system by introducing nitrogen and air separately; Step 3: Adjust the water pump speed and control the water flow rate, and adjust the heater temperature to control the temperature of the circulating water; Step 4: Stop supplying nitrogen into the fuel cell, introduce hydrogen into the hydrogen humidifier for bubbling humidification, and introduce air into the air humidifier for bubbling humidification. The humidity level (RH) should be 60-100%. An open-circuit voltage should be established in the test system. Step 5: Control the opening of the hydrogen back pressure valve and the air back pressure valve, and adjust the pressure at the anode inlet of the fuel cell to 60 kPa and the pressure at the cathode inlet to 40 kPa; after the temperature rises to 50°C, turn on the electronic load control module to activate the fuel cell; Step Six: Introduce air and hydrogen of different concentrations into the fuel cell to generate electricity and detect the parameters of the power generation process.

9. The test method according to claim 8, characterized in that: In step two, nitrogen gas is introduced into the system at a rate of 10-20 L / min to purge the system, and air is introduced into the system at a rate of 30-40 L / min to purge the system for 3-5 minutes.

10. The test method according to claim 8, characterized in that: The anode inlet of the fuel cell is connected to a hydrogen solenoid valve, and the cathode inlet of the fuel cell is connected to an air solenoid valve. After completing the test, the electronic load control module is unloaded until the fuel cell is in an open-circuit voltage state. Then, the inlet pressure of the anode and cathode of the fuel cell is set to 0. When the inlet pressure of the anode and cathode of the fuel cell both drop to zero, the hydrogen solenoid valve and the air solenoid valve are opened to switch to the dry circuit state. Hydrogen continues to flow into the test system while the introduction of air into the test system is stopped. The electronic load control module is kept connected. When the individual voltage of the fuel cell stack drops to 0.2V, the hydrogen flow is shut off and the electronic load control module is disconnected.

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