Effects of temperature, inlet gas pressure and humidity on PEM water contents and current density distribution

The liquid water content directly affects the performance of the proton exchange membrane fuel cell (PEMFC). However, the liquid water content is influenced by the temperature, inlet gas pressure and humidity, so this investigation seeks to explore the relationship among the operating parameters, liquid water content and the current density distribution that used to characterize the cell performance. Firstly, a three-dimensional monomer model of PEMFC was established for numerical simulation based the COMSOL software to study the effect of temperature and inlet gas parameters on cell performance. Then the PEMFC reactor performance test used control variable method was carried out on the 15 kW test bench to verify the research. From the simulation and test results, we can acquire that the liquid water content and current density distribution of fuel cell are the maxima under the condition of 0.2 MPa pressure and 100% humidification. Finally, the experiment confirmed that when the temperature is 353 K, the liquid water content is the highest, and when the temperature remains constant, the higher inlet gas pressure and humidity was given, the higher liquid water content will be generated in the proton membrane which can increase the current density on the membrane to a certain extent, hence to improve the cell performance.