Analyses of mass and heat transport interactions in a direct methanol fuel cell

In this paper, a two-dimensional, two-phase, non-isothermal model is presented to predict the electrochemical, mass transfer and heat transfer behaviors in a direct methanol fuel cell (DMFC). Governing equations including the momentum, continuity, heat transfer, proton and electron transport, species transport for water, methanol, and all the gas species (carbon dioxide, methanol vapor, water vapor, oxygen, and nitrogen) and the auxiliary equations are coupled to studying the various phenomena in DMFC. The modeling results agree well with the four different experimental data in an extensive range of operation conditions. A parametric study is also performed to examine the effects of the cell voltage on the different variables, such as cell temperature, liquid methanol concentration distribution, oxygen concentration distribution, and anode gas pressure distribution. The results show that the cell temperature is highly sensitive to the change in the cell voltage as well as methanol concentration distribution. Moreover, it is found that the cell voltage significantly influences the oxygen concentration distribution and the anode gas pressure distribution.