Effects of Inlet Gas Temperature and Relative Humidity on Performance Characteristics of PEM Fuel Cell

Abstract:

A one-dimensional， non-isothermal， two-phase model was employed to investigate the effects of inlet gas temperature and relative humidity （RH） on the output performance of proton exchange membrane fuel cell （PEMFC）. A cathode catalyst layer （CL） agglomerate sub-model was also coupled into the model to consider the impact of the micro-structure in CL. It is found that the influence of operating temperature on the output performance of PEMFC is limited at the dry case （RHa50%/RHc50%）. The highest current density at various operating temperatures corresponds to different RH conditions. When the operating temperature is 90℃， the highest current density is attained at the RHa 90% / RHc 50% case， while a lower inlet temperature （70℃） has the highest current density at the RHa 90% /RHc 90% case. Additionally， when the RHa is constant at 90% and RHc is kept at a low level （0?50%）， the RHc corresponding to the maximum power density is lower with a higher temperature based on particle swarm optimization. Under whole operating conditions， the peak power density can be up to 0.88 W/cm2 when the operating temperature is 90℃ and RHc is 14.6%.

Key words:proton exchange membrane fuel cell;inlet temperature;relative humidity;particle swarm optimization