Integrating full fan morphology and configuration in three-dimensional simulation of air-cooled proton exchange membrane fuel cell stack

The internal water and thermal state and performance of an air-cooled proton exchange membrane (PEM) fuel cell stack are strongly determined by the fan arrangement and operational characteristics. This study presents an innovative method to investigate the influence of fan on stack performance through integration of fan’s full morphology, including the fan blade, grill between the fan and stack, etc. into a three-dimensional (3D) multiphase stack model. The multiple reference frame (MRF) model is implemented to simulate the air flow field caused by the rotation of fan and the multiple transfers coupled with electrochemical reactions is considered in the 3D stack model in detail. Through this integrated model, the influence of the air supply mode, fan number and duty ratio on stack performance and the distribution characteristics are investigated in detail. It is found that the air flowing into each cell in the fan-cooled stack is highly non-uniform, which increases the variations of oxygen concentration, temperature, and voltage in the stack. In comparison with the blowing mode, the suction mode helps to promote the uniformity of air supply with a lower air flow velocity.