Air-cooled fuel cell testing apparatus and method

Abstract

The application discloses an air-cooled fuel cell testing device and method, and relates to the technical field of fuel cell testing. The device comprises a blind end plate, an air inlet end plate, a fuel cell, a fan and a sensor. The fan is integrated with an air supply channel and a cathode flow field plate flow field area. The cathode flow field inlet and outlet adopt L-shaped channels, which are compact in structure and reliable in sealing. The method obtains the fan wind pressure through the cathode outlet pressure and the ambient pressure, obtains the air flow based on the wind pressure and the air volume curve, calculates the heat dissipation power based on the inlet and outlet temperature difference, and obtains the heat generation power, the heat dissipation efficiency and the fan efficiency based on the electric parameters. The application can simulate the whole machine fan direct supply working condition, realizes the heat-flow-electricity coupling test, is suitable for small area cells, has high testing precision and good repeatability, and is suitable for the research and development and performance evaluation of air-cooled fuel cells.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and in particular to an air-cooled fuel cell testing device and an air-cooled fuel cell testing method based on the device. Background Technology

[0002] Air-cooled fuel cells are compact and require no water cooling system, making them widely used in mobile devices such as drones and portable power supplies. The coupling performance of their cathode air supply and heat dissipation directly determines the overall compatibility of the device. Current testing methods often use flow meters to control flow and pressure, which is disconnected from actual direct fan supply conditions. This makes it impossible to simulate the matching relationship between fan pressure-volume and flow resistance, resulting in low engineering reference value. Traditional devices require external air paths and connectors; small clamps are prone to seal failure, have poor portability, and are difficult to use for high / low temperature and vibration environmental testing. Furthermore, air supply and heat dissipation are independent, making it impossible to achieve "air supply equals heat dissipation" thermal-fluid coupling testing, and difficult to quantify heat dissipation efficiency and fan efficiency. Existing direct fan supply clamps are mostly designed for large-size batteries; when used for small-area samples, they exhibit poor surface wind speed uniformity, are difficult to arrange micro-sensors, and speed fluctuations can lead to unreproducible results. They also cannot simulate dynamic wind conditions and under-air supply failure conditions. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of distorted test conditions, complex structure, inability to perform thermal-fluid coupling tests, and poor adaptability of small-area samples in existing air-cooled fuel cells. This invention adopts an integrated design of fan, air supply duct and cathode flow field plate flow field area, with L-shaped channels at the cathode flow field inlet and outlet, and multi-point temperature and pressure sensors to form a compact and reliable test device. The test method is based on the air pressure to infer the air flow rate, and the heat dissipation power is calculated by combining the inlet and outlet temperature difference, so as to complete the calculation of heat generation power, heat dissipation efficiency and fan efficiency, and realize the test of thermal-fluid-electric coupling parameters.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An air-cooled fuel cell testing device,

[0006] It includes a blind end plate and an air inlet end plate, and a fuel cell is disposed between the blind end plate and the air inlet end plate. The fuel cell is composed of an anode flow field plate and a cathode flow field plate.

[0007] A fan is connected to one side of the air inlet end plate. The cathode flow field plate is provided with a cathode flow field plate inlet, a cathode flow field plate flow field area and a cathode flow field plate outlet in sequence. The fan is integrated with the air supply duct and the cathode flow field plate flow field area.

[0008] Both the cathode flow field plate inlet and the cathode flow field plate outlet are L-shaped channels, with one end of each L-shaped channel connected to both ends of the cathode flow field plate flow field region.

[0009] A cathode outlet temperature sensor and a cathode outlet pressure sensor are installed at the air supply duct, and a cathode inlet temperature sensor is installed at the inlet of the cathode flow field plate.

[0010] Preferably, the contact surfaces of the anode flow field plate and the cathode flow field plate are provided with a sealing assembly.

[0011] Preferably, the blind end plate and the air intake end plate are connected around their perimeter by a number of fasteners.

[0012] Preferably, the anode flow field plate is connected in sequence to an anode current collector plate and an anode insulating plate on the side near the blind end plate.

[0013] Preferably, a cathode collector plate and a cathode insulating plate are sequentially connected to the side of the cathode flow field plate near the air inlet end plate.

[0014] Preferably, a hydrogen inlet connector is provided on one side of the anode flow field plate.

[0015] A method for testing an air-cooled fuel cell includes the following steps:

[0016] S1: The fan pressure is obtained by the cathode outlet pressure sensor on the air supply duct and the ambient pressure;

[0017] S2: Obtain the cathode airflow rate through the fan's air pressure and airflow curve. ;

[0018] S3: Collect the values ​​from the cathode outlet temperature sensor and the cathode inlet temperature sensor to obtain the temperature difference between the cathode inlet and outlet air. ;

[0019] S4: Combined with airflow Specific heat capacity of air Through formula The air-cooled heat dissipation power was calculated.

[0020] S5: Through formula The heat output power of the air-cooled fuel cell was calculated.

[0021] S6: Calculate the heat dissipation efficiency and fan efficiency ;

[0022] S7: The above parameters and curves are displayed on the display device through the signal acquisition module and the calculation module.

[0023] Preferably, the environmental pressure in step S1 is acquired by an environmental pressure sensor, and the fan's air pressure and air volume curves in step S2 are pre-stored in the calculation module.

[0024] Preferably, the step S5 described The output voltage of the fuel cell, the This represents the output current of the fuel cell.

[0025] Preferably, the curves displayed by the display device in step S7 include heat dissipation power-fan speed curve, heat generation power-fan speed curve, heat dissipation efficiency-fan speed curve, and fan efficiency-fan speed curve.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention employs an integrated structure, realistically replicating the direct fan supply operating condition, resulting in high consistency between test results and overall system operation. The device has no external air path, featuring a compact structure, excellent sealing, and high portability, enabling testing in various environmental environments. The integrated air supply and heat dissipation allows for simultaneous measurement of oxygen supply and heat dissipation parameters, accurately quantifying heat dissipation efficiency and fan efficiency, and achieving heat-fluid coupling testing. The L-shaped channel optimizes surface wind speed distribution, and the rationally arranged micro-sensors ensure stable and controllable rotational speed, resulting in high testing accuracy and repeatability. It can simulate dynamic wind conditions and under-supply conditions, comprehensively covering the R&D and testing needs of small-area air-cooled fuel cells. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the structure from another perspective of the present invention.

[0030] Figure 3 for Figure 2 Sectional view at point AA.

[0031] Figure 4 for Figure 3 Enlarged view of point C.

[0032] Figure 5 This is a partial structural diagram of the present invention.

[0033] Figure 6 This is the interface for the fuel cell heat dissipation efficiency test results of this invention.

[0034] Figure 7 This is the interface for the test results of the oxygen supply efficiency of the fuel cell in this invention.

[0035] In the diagram: 1. Blind end plate; 2. Fan; 3. Air supply duct; 4. Cathode inlet temperature sensor; 5. Fastener; 6. Cathode outlet temperature sensor; 7. Cathode outlet pressure sensor; 8. Anode flow field plate; 9. Anode insulating plate; 10. Hydrogen inlet connector; 11. Inlet end plate; 12. Cathode insulating plate; 13. Anode manifold; 14. Cathode manifold; 15. Fan outlet; 16. Cathode flow field plate inlet; 17. Cathode flow field plate outlet; 18. Air inlet; 19. Cathode flow field plate flow field area; 20. Sealing assembly; 21. Cathode flow field plate. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] This invention discloses a testing device and method for air-cooled fuel cells, mainly applicable to the performance testing of single cells and short stacks of small-area air-cooled proton exchange membrane fuel cells. It can accurately reproduce the actual operating conditions of air-cooled fuel cells and perform precise measurements of thermal-fluid coupling parameters. The device structure, working process, and testing method are described in detail below with reference to embodiments.

[0038] Example 1

[0039] This embodiment provides a detailed description of the structure and operation of the air-cooled fuel cell test device.

[0040] like Figures 1 to 5 As shown, the air-cooled fuel cell test device includes a blind end plate 1, an air inlet end plate 11, fasteners 5, a fuel cell, a fan 2, an air supply duct 3, a cathode inlet temperature sensor 4, a cathode outlet temperature sensor 6, a cathode outlet pressure sensor 7, a sealing assembly 20, an anode current collector 13, an anode insulating plate 9, a cathode current collector 14, a cathode insulating plate 12, and a hydrogen inlet connector 10.

[0041] The blind end plate 1 and the air intake end plate 11 are located at opposite ends of the device and are connected around their perimeter by multiple fasteners 5, forming a stable clamping structure. Both the blind end plate 1 and the air intake end plate 11 are made of lightweight, high-strength materials, providing stable support for internal components while ensuring the rigidity of the overall structure. This prevents deformation during long-term use, which could affect the assembly accuracy and sealing performance of the fuel cell. The fasteners 5 are evenly distributed around the end plates, using a symmetrical fastening method to ensure uniform clamping force on the fuel cell. This guarantees uniform contact between the anode flow field plate 8, the cathode flow field plate 21, and the membrane electrode assembly, maintaining stable electrical contact and sealing.

[0042] The fuel cell is located between the blind end plate 1 and the air inlet end plate 11, and consists of an anode flow field plate 8 and a cathode flow field plate 21 in conjunction with a membrane electrode assembly (MEA). The anode flow field plate 8 is used to distribute and transport hydrogen, while the cathode flow field plate 21 is used to distribute, transport, and dissipate heat from the air. Both the anode flow field plate 8 and the cathode flow field plate 21 are made of materials with good electrical conductivity and corrosion resistance, and their surfaces are equipped with suitable flow channel structures to ensure uniform gas distribution on the MEA surface and stable electrochemical reactions.

[0043] A fan 2 is installed on the outer side of the air inlet end plate 11, and the air outlet of the fan 2 is connected to the air inlet 18 on the air inlet end plate 11. When the fan 2 is running, it generates a stable airflow to provide the air required for the reaction on the cathode side, and at the same time achieves forced heat dissipation of the battery. The fan 2 is integrated with the air supply duct 3 and the cathode flow field plate flow field area 19. After the air enters from the air inlet 18, it flows sequentially through the cathode flow field plate inlet 16, the cathode flow field plate flow field area 19, and the cathode flow field plate outlet 17, enters the air supply duct 3, and is finally discharged from the fan outlet 15, forming a continuous closed airflow path with no additional leakage. The airflow path is completely consistent with the actual working state of the air-cooled fuel cell.

[0044] The cathode flow field plate 21 is sequentially configured with a cathode flow field plate inlet 16, a cathode flow field plate region 19, and a cathode flow field plate outlet 17. Multiple contact strips are distributed on the surface of the cathode flow field plate region 19, which are in close contact with the membrane electrode, supporting the membrane electrode and efficiently discharging the current generated by the electrochemical reaction, thus reducing ohmic losses. Both the cathode flow field plate inlet 16 and the cathode flow field plate outlet 17 are L-shaped channels, connected to opposite ends of the cathode flow field plate region 19. These L-shaped channels buffer and rectify the incoming and outgoing airflow, resulting in a more uniform airflow distribution within the cathode flow field plate region 19, improving face velocity consistency, preventing uneven reaction and temperature deviations caused by excessively fast or slow local airflow, and enhancing the accuracy and stability of the test results.

[0045] Air supply duct 3 is connected to cathode flow field plate outlet 17. Cathode outlet temperature sensor 6 and cathode outlet pressure sensor 7 are installed on air supply duct 3. Cathode outlet temperature sensor 6 is used to detect the temperature of the air flowing out of the cathode flow field, and cathode outlet pressure sensor 7 is used to detect the gas pressure at the cathode outlet. Cathode inlet temperature sensor 4 is installed at cathode flow field plate inlet 16 to detect the temperature of the air entering the cathode flow field. All of the above sensors adopt a miniature structure and are installed close to the airflow channel, which will not significantly obstruct the airflow. They have fast measurement response and high accuracy, and can reflect the temperature and pressure status of the cathode inlet and outlet in real time, providing reliable data for subsequent calculation of parameters such as heat dissipation power and airflow.

[0046] A sealing assembly 20 is installed at the contact surface between the anode flow field plate 8 and the cathode flow field plate 21. The sealing assembly 20 is arranged around the reaction region of the fuel cell to block the anode hydrogen and cathode air, preventing gas cross-contamination and leakage. The sealing assembly 20 uses an elastic sealing material that can undergo appropriate compression deformation under assembly pressure to fill the gap between the contact surfaces, achieving a reliable seal, ensuring the safety and stability of the test process, and preventing leakage from affecting test accuracy.

[0047] An anode current collector 13 and an anode insulating plate 9 are sequentially arranged on the side of the anode flow field plate 8 closest to the blind end plate 1. The anode current collector 13 is used to collect the current generated on the anode side to ensure stable current output. The anode insulating plate 9 separates the anode current collector 13 from the blind end plate 1, achieving electrical insulation, preventing leakage and short circuits, and improving safety in use.

[0048] A cathode current collector 14 and a cathode insulating plate 12 are sequentially arranged on the side of the cathode flow field plate 21 near the air inlet end plate 11. The cathode current collector 14 is used to collect the current on the cathode side, and together with the anode current collector 13, it forms a complete current output circuit. The cathode insulating plate 12 separates the cathode current collector 14 from the air inlet end plate 11, achieving electrical insulation, preventing current from forming a short circuit through the end plate, and ensuring electrical safety during the testing process.

[0049] A hydrogen inlet connector 10 is provided on one side of the anode flow field plate 8. The hydrogen inlet connector 10 is used to connect to an external hydrogen source. Hydrogen enters the anode flow field plate 8 through the hydrogen inlet connector 10 and is evenly distributed on the anode side to provide fuel for the electrochemical reaction. The hydrogen inlet connector 10 has a reliable connection, good sealing performance, and can be adapted to conventional hydrogen supply pipelines, facilitating the rapid construction of the test gas circuit.

[0050] During operation, hydrogen gas enters the anode flow field plate 8 through the hydrogen inlet connector 10 and undergoes an oxidation reaction on the anode catalyst surface. Fan 2 drives air in through the air inlet 18, flows into the cathode flow field plate flow field region 19 through the cathode flow field plate inlet 16, and the oxygen in the air undergoes a reduction reaction on the cathode catalyst surface, generating water and releasing heat. As the air flows through the cathode flow field plate flow field region 19, it provides oxygen for the reaction and simultaneously removes the heat generated by the electrochemical reaction through forced convection, achieving integrated oxygen supply and heat dissipation. The reacted air enters the air supply duct 3 through the cathode flow field plate outlet 17 and is finally discharged through the fan outlet 15. The cathode inlet temperature sensor 4, cathode outlet temperature sensor 6, and cathode outlet pressure sensor 7 collect temperature and pressure signals at their respective locations in real time, providing basic data for the testing method. The anode current collector 13 and cathode current collector 14 stably output the current generated by the electrochemical reaction, enabling performance testing under different operating conditions in conjunction with an external electronic load.

[0051] The device in this embodiment eliminates external gas paths, flow meters, regulating valves, and other components, resulting in a compact, small, lightweight, and easily portable overall structure. It can be tested in conventional laboratory environments, high and low temperature environments, and vibration environments, making it applicable to a wider range of scenarios. Furthermore, the device utilizes direct air supply from Fan 2, consistent with actual system operating conditions, ensuring test results more closely reflect real-world usage. This provides a reliable basis for the research, optimization, and system matching of air-cooled fuel cells.

[0052] Example 2

[0053] This embodiment provides a detailed explanation of the implementation process and parameter calculation logic of the air-cooled fuel cell testing method.

[0054] This method is implemented based on the aforementioned air-cooled fuel cell test device. By measuring temperature, pressure and electrical parameters in conjunction with the air pressure and air volume characteristics of fan 2, the heat dissipation power, heat generation power, heat dissipation efficiency and fan efficiency are calculated, thus realizing a comprehensive test of the thermal-fluid-electric coupling performance of the air-cooled fuel cell.

[0055] Before the test, an airtightness check was performed on the device to confirm that there were no leaks in the hydrogen and air circuits, ensuring test safety. The device was then connected to the hydrogen source, electronic load, signal acquisition module, calculation module, and display device. The sensors were calibrated to ensure measurement accuracy, and the air pressure and airflow curves of fan 2 were pre-stored in the calculation module to provide a data basis for subsequent airflow calculation.

[0056] After the test is started, hydrogen is first introduced to ensure a stable flow of hydrogen into the anode flow field plate 8, maintaining a suitable hydrogen supply pressure to ensure stable reaction conditions for the fuel cell. Fan 2 is then started and a target speed is set. Once the fan 2 speed stabilizes and the fuel cell operation becomes stable, parameter measurements and calculations are performed.

[0057] First, the gas pressure at the cathode outlet is acquired using cathode outlet pressure sensor 7, and the current ambient atmospheric pressure is obtained simultaneously through environmental pressure measurement. The difference between the cathode outlet pressure and the ambient atmospheric pressure is calculated to obtain the air pressure of fan 2. Based on this air pressure, the calculation module calls upon pre-stored air pressure and airflow curves and calculates the cathode airflow under the current operating conditions through interpolation. This method eliminates the need for a flow meter in the air path, does not alter the flow field resistance, and provides measurement results that more closely reflect the actual air supply conditions, effectively improving the accuracy of airflow.

[0058] After the airflow and battery temperature stabilize, the cathode inlet air temperature is collected by cathode inlet temperature sensor 4, and the cathode outlet air temperature is collected by cathode outlet temperature sensor 6. The difference between the two temperatures is calculated to obtain the temperature difference between the cathode inlet and outlet air. To improve measurement accuracy, multiple data collections can be performed within a short period of time, and the average value can be taken to reduce errors caused by random fluctuations.

[0059] Get airflow With temperature difference Then, combined with the specific heat capacity of air According to the formula Calculate the air-cooled heat dissipation power. Air-cooled heat dissipation power represents the amount of heat carried away by the air from the fuel cell per unit time, directly reflecting the heat dissipation capacity of the air-cooled fuel cell.

[0060] Simultaneously, the output voltage of the fuel cell is acquired via an electronic load. With output current According to the formula Calculate the heat power generated by the fuel cell. This formula is based on the energy balance relationship of the fuel cell and can accurately reflect the heat power generated by the irreversible electrochemical reaction process, achieving reliable calculation without the need for additional heat flux sensors.

[0061] After obtaining the heat dissipation power and the heat generation power, calculate the heat dissipation efficiency. Heat dissipation efficiency characterizes the proportion of heat generated by the battery that is effectively carried away by air, reflecting the degree of matching between the heat dissipation system and the fuel cell. Simultaneously, the input power of fan 2 is measured. Calculate fan efficiency Fan efficiency is used to characterize the proportion of input energy of fan 2 that is converted into effective heat dissipation energy, reflecting the working efficiency of fan 2.

[0062] Reference Figures 6 to 7 The signal acquisition module transmits raw signals such as temperature, pressure, voltage, current, and speed to the calculation module in real time. The calculation module processes, stores, and fits curves to the data, and finally outputs parameters such as fan speed, cathode inlet temperature, cathode outlet temperature, air pressure, airflow, heat dissipation power, heat generation power, heat dissipation efficiency, and fan efficiency, as well as curves such as heat dissipation power-fan speed, heat generation power-fan speed, heat dissipation efficiency-fan speed, and fan efficiency-fan speed to the display device in real time, so that testers can observe, record, and analyze them intuitively.

[0063] This method can conduct tests under various operating conditions. In static testing, the speed of fan 2 can be adjusted step-by-step, while the output current of the electronic load can be adjusted step-by-step to cover the commonly used operating range of the fuel cell, obtaining a complete performance spectrum and determining the optimal heat dissipation matching point and optimal operating range. In dynamic testing, fan 2 can be adjusted according to a preset speed curve to simulate dynamic wind conditions such as takeoff, cruise, and hovering, while simultaneously matching dynamic loads, observing the fuel cell's response speed, temperature fluctuations, and output stability under dynamic operating conditions. In fault simulation testing, the speed of fan 2 can be reduced to simulate under-air supply faults, observing battery temperature changes and output performance degradation patterns, providing a basis for safety protection strategy design.

[0064] After the test is completed, gradually reduce the load current, shut off the hydrogen supply, and stop fan 2 after the fuel cell voltage drops to zero to complete the test process.

[0065] This method enables simultaneous testing and coupled analysis of air supply, heat dissipation, and electrical performance, solving the problem that traditional tests cannot quantify heat dissipation efficiency, fan efficiency, and oxygen supply efficiency. The testing process is simple, the data is comprehensive, and the results are reproducible, providing complete data support for the structural optimization of air-cooled fuel cells, fan selection, thermal management design, and control system development.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air-cooled fuel cell testing method, characterized by, Includes the following steps: S1: The air pressure of the fan (2) is obtained by the cathode outlet pressure sensor (7) on the air supply duct (3) and the ambient pressure; S2: Obtain the cathode air flow rate through the wind pressure and air volume curve of the fan (2) ; S3: Collect the values of the cathode outlet temperature sensor (6) and the cathode inlet temperature sensor (4) to obtain the temperature difference of the air at the inlet and outlet of the cathode ; S4: Combined with airflow Specific heat capacity of air Through formula The air-cooled heat dissipation power was calculated. S5: Through formula The heat output power of the air-cooled fuel cell was calculated. S6: Calculate the heat dissipation efficiency and fan efficiency ; S7: The above parameters and curves are displayed on the display device through the signal acquisition module and the calculation module. The curves displayed by the display device include heat dissipation power-fan speed curve, heat generation power-fan speed curve, heat dissipation efficiency-fan speed curve and fan efficiency-fan speed curve. The parameters include fan speed, cathode inlet temperature, cathode outlet temperature, air pressure, air flow, heat dissipation power, heat generation power, heat dissipation efficiency and fan efficiency. The air-cooled fuel cell testing method is applied to an air-cooled fuel cell testing device, which includes a blind end plate (1) and an air inlet end plate (11). A fuel cell is disposed between the blind end plate (1) and the air inlet end plate (11). The fuel cell is composed of an anode flow field plate (8) and a cathode flow field plate (21). A fan (2) is connected to one side of the air inlet end plate (11). The cathode flow field plate (21) is provided with a cathode flow field plate inlet (16), a cathode flow field plate flow field area (19) and a cathode flow field plate outlet (17) in sequence. The fan (2) is integrated with the air supply duct (3) and the cathode flow field plate flow field area (19). The cathode flow field plate inlet (16) and cathode flow field plate outlet (17) are both L-shaped channels, and one end of each L-shaped channel is connected to both ends of the cathode flow field plate flow field region (19); A cathode outlet temperature sensor (6) and a cathode outlet pressure sensor (7) are installed at the air supply duct (3), and a cathode inlet temperature sensor (4) is installed at the cathode flow field plate inlet (16).

2. The air-cooled fuel cell testing method according to claim 1, characterized in that, The environmental pressure mentioned in step S1 is obtained by an environmental pressure sensor, and the wind pressure and air volume curve of the fan (2) mentioned in step S2 is pre-stored in the calculation module.

3. The air-cooled fuel cell testing method according to claim 1, characterized in that, The steps described in step S5 The output voltage of the fuel cell, the This represents the output current of the fuel cell.

4. The air-cooled fuel cell testing method according to claim 1, characterized in that, The contact surfaces of the anode flow field plate (8) and the cathode flow field plate (21) are provided with sealing components (20).

5. The air-cooled fuel cell testing method according to claim 1, characterized in that, The blind end plate (1) and the air intake end plate (11) are connected around their perimeter by a number of fasteners (5).

6. The air-cooled fuel cell testing method according to claim 1, characterized in that, The anode flow field plate (8) is connected in sequence to the anode current collector plate (13) and the anode insulating plate (9) on the side near the blind end plate (1).

7. The air-cooled fuel cell testing method according to claim 1, characterized in that, The cathode flow field plate (21) is connected in sequence to the cathode collector plate (14) and the cathode insulating plate (12) on the side near the air inlet end plate (11).

8. The air-cooled fuel cell testing method according to claim 1, characterized in that, A hydrogen inlet connector (10) is provided on one side of the anode flow field plate (8).

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