Investigation of the Ice Melting Process in a Simplified Gas Diffusion Layer of Fuel Cell by the Lattice Boltzmann Method

Cold start is a challenge for the proton exchange membrane fuel cell, and understanding the heat transfer characteristics of solid–liquid phase change in this process is necessary. An enthalpy-based lattice Boltzmann model is established, and the heat transfer of ice melting in in-plane and through-plane of the gas diffusion layer (GDL) is studied. The effects of fiber diameter, double heat sources, and Rayleigh number are analyzed. It is found that the fiber diameter has a significant influence on heat transfer. The ice melting rate of XZ position is faster than other planes, and it has the best effect when the diameter is 8 μm. The heat transfer of different heating positions is analyzed, and it is found that the left-right-heated has the highest melting efficiency. The heat sources location has different effects on the heat transfer between the XY position (TP1) and YZ position (TP2). Although the increase of Rayleigh number can enhance the convective heat transfer, the change of melting efficiency is extremely small. The convective heat transfer intensity has no direct effect on the ice melting of GDL, and fiber plays a more critical role in the heat transfer of ice melting.