Influence of Design Anode and Cathode Channel on (PEMFC) Fuel Cell Performance

Fell cell

1. Influence of Design Anode and Cathode Channel on (PEMFC) Fuel Cell Performance Dr :Yasir Al- Okbi , * Department of Mechanical and Aerospace Engineering, Brunel University London, United Kingdom University of Baghdad, Iraq

2. Figure 2 : Schematic diagram of dual layer GDL for PEM fuel cells [ 2 ]. Figure 1: Diagram to explain fuel cell basic operation. [1] Background – review of fuel cell basic operation

3. Research structure Background – review of aerofoil leading edge modifications Experimental set up Boundary Conditions and Parameters Flow Field Analysis Water Channel Designs Analysis Conclusions

4. Aims and objectives - Design of an integrated proton exchange membrane fuel cell . Analysis of all currently utilised storage mediums was undertaken. High and low inlet operating conditions were studied by determining the distributions of over potentials, velocity distribution, and pressure. At entrance and exit, A triangle channel flow-field was predicted to have better polarization performance and regular velocity distribution, whereas for rectangular that was performance differences among four serpentine flow-fields for hydrogen and air. The pressure in the triangle channels were monitored to have periodically similar plots and showed important low pressure drop. -The study found that the triangular channels produced a better performance than their square flow path counterparts.

5. Experimental Work Figure 4 : Air Flow Calibration Setup Figure 3: Fully assembled single stack Fuel Cell. Figure 5: Fuel Cell Test Setup.

6. Design conception of the fuel cell Figure 6: 2D cross sectional schematic showing concept behind triangular channels and the increased reaction area they provide.

7. In the anode side channel, hydrated hydrogen is present and in the cathode channel, air is modelled flowing through it. The air is modelled as nitrogen, oxygen and water vapour. The model is solved for a range of voltages from 0.9V to 0.15V. The model outputs a polarisation plot for the cell and the concentrations of hydrogen, oxygen and water in their respective channels and GDLs. Boundary Conditions and Parameters

8. Flow Field Analysis (left), surface map of velocity compares between 3D triangle and (right), 3D rectangular for air. (left), a surface map of velocity vectors magnitude compares between 3D triangle and (right) 3D rectangular for air.

9. Velocity and pressure profiles in the channels for design.

10. Water Channel Designs Analysis Velocity surface plots for the water channel designs.   Power Curve - Rectangular and triangular channel design comparison.

11. The result for the power of both the triangular and rectangular channel designs shows that the triangular design improves the performance of the fuel cell can be seen in figure 10. The peak performance recorded during the investigations was improved by 25.8%, from 0.64W to 0.87W . the flow rate of supplied hydrogen and air into the fuel cell is required to fully understand the capability of the fuel cell design. The pressure drop for total and static become decreased for triangle 3D model compares with rectangle model and the pressure drop for triangle in current work became better than from rectangular that reached about 1.39pa total and 0.837pa for total pressure compare the rectangular is 3.35 max total pressure. Velocity along channels will be reached to 0.35m/s versus that one with the rectangular channel that is reached to 0.39 m/s. The velocity plot shows the maximum value at the centre of each channel . The velocity vectors were improved from rectangle channel to triangle channel the velocity distribution in the inlet and outlet become better than from rectangular the back drop for fluid was very large in the corners of the model especial in each serpentine. Conclusions