A mathematical model is developed to analyze numerically coal pyrolysis and heat transfer inside a heated coal particle.Endothermic effect of decomposition and transpirational convective heat transfer are taken into account.A coupled comprehensive model was validated with experimental data of pulverized coal and large particles.Then,temperature history and coal pyrolysis of coal particle heated were analyzed numerically.Effects of endothermic of pyrolysis,transpirational convection,volatile content and particle size were investigated to understand physically transient temperature and volatile evolution of coal particle.

A non-isothermal three-dimensional(3 D) two-phase flow transport model is developed for a proton exchange membrane fuel cell(PEM FC) with straight flow channels.Based on characteristics of water transport between membrane and gas phase,a non-equilibrium model is developed for liquid water transport in membrane,considering electroosmosis,concentration diffusion and electrochemical reaction.A finite volume method is used to discretize governing equations and solution code is developed.The model is used to simulate multi-physical field coupled transport in a PEMFC.Investigations are performed for water vapor concentration,liquid water saturation,membrane water content distribution and liquid water transport velocity.Temperature field inside a cell and predicted polarization are obtained.