Sensitivity analysis of the proton exchange membrane fuel cell cold start process with the numerical method

A three-dimensional multiphase flow cold start model is established in this article to study the cold start performance of proton exchange membrane fuel cell (PEMFC) which comprehensively considers the phase transition and transfer process of liquid water. First, the impact of different parameters on cold start performance is studied, including porosity, contact angle, ionomer volume fraction, and specific heat capacity, which explains the impact of various parameters on different cold start processes and is the basis for parameter selection in subsequent sensitivity analysis research. Then, a sensitivity analysis of the fuel cell cold start performance to various parameters is conducted, which quantifies the factors that affect the cold start performance. Finally, the effect of three different current loading methods on cold start performance is analyzed by changing the rising slope, initial current density, and duration. The results show that the cold start duration and temperature rise of the fuel cell are positively correlated with other parameters except for specific heat capacity. Specific heat capacity has the greatest impact on the temperature rise, and the catalyst layer (CL) contact angle has the greatest impact on the cold start duration. The current loading method of linear rising or stepwise rising can avoid the problem of insufficient heat generation caused by low current density during constant current cold start and can also avoid the problem of rapid freezing rate caused by high current density, which can lead to the failure of cold start.