| Summary: | 碩士 === 中原大學 === 機械工程研究所 === 95 === This study is aimed at under the various geometry of flow channels which affect the proton exchanges membrane fuel cell performance by using the (Computational fluid dynamic) software CFDRC to simulate. Consider the counter flow channel as the basic model at first and choosing different temperature condition of the cell cathode flow inlet direction. After collecting the data of suitable operating conditions, to discuss the five different flow channels and comparing to one another .The following step is to change different gas diffusion layers porosity and cathode inlet velocities. Finally, to make the discussion including the different flow channels which affect on the performance of the cell.
The simulation result shows the temperature of the cell for 333K and the temperature of the flow inlet for 323K while the flow direction is just on the opposite side and cell performance is best. Under the same operating condition for serpentine channel、interdigitated channel and Z type-interdigitated channel exist uniform local current density distribution and the value of the maximum current density is higher than other kinds of channel. So, the optimum cell performance will be obtained as well. In different kinds of flow channels, as if the diffusion layers porosity is getting larger, the electric current density will increase too. The effect of cathode flow inlet velocity to the different channel types, parallel channel,Z type-interdigitated channel and interdigitated-parallel channel as the flow velocity up to 8.75 , we can get the maximum current density. On the other hand, serpentine channel and interdigitated channel under the inlet velocity of 5.25 , gas can abundant and effective diffuse to the catalyst layer to induce chemical reaction in there, and we will obtain the higher performance while under the certain specified velocity .
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