A computational fluid dynamics study to evaluate the effect of an air-cooled fuel cell stack using a turbulence inducing grid under transient operating conditions

Lind, Alexander Strømfeldt

4. term

Energy Engineering, Master

2019

2019-05-30

56 pages

Cooling a Proton Exchange Membrane Fuel Cell (PEMFC) using only air flow is gaining popularity as a cooling method due to its low cost and simplicity. Fuel cells that use air cooling are already commercialized up to a power range of a few kWs. These fuel cells are limited in current density, and by extension power density, in the amount of heat that can be effectively dissipated by the airflow. By placing a grid in front of the cathode flow channel of the fuel cell stack, experiments have shown the power density could be increased by over 30\% as a direct consequence of increased convective cooling. This study uses Computational Fluid Dynamics (CFD) to verify and quantify the effect of a turbulence inducing grid placed at various distances from the cathode channel, as well as under transient operating conditions. At an electrode heat flux of 2587 W/m2 the study showed that the average temperature of the Gas Diffusion Layer (GDL) and bipolar plates could be reduced by 2.5°C with a turbulence inducing grid. A further temperature reduction of the GDL between 0.3-2°C was seen by continuously varying the speed of the cooling fan.

Fuel Cell ; PEMFC ; Turbulence ; Air-cooling ; CFD ; Transient ; Heat Transfer

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