In this paper, a numerical model of gas flow, heat transfer, mass transfer and electrochemical reaction multi-physics field coupling of a planar SOFC is established and solved. According to the calculation results, the distribution of velocity, temperature and concentration inside the SOFC cell is analyzed. The influence of cathode inlet flow rate, porosity, rib width and other parameters on the performance of SOFC is also discussed. The results show that within a certain range, increasing the cathode inlet flow rate can significantly increase the average current density of the cell. Increasing the porosity of the electrode can improve the gas diffusion of the porous electrode, thereby increasing the rate of the electrochemical reaction. Increasing the width of the ribs will result in a significant decrease in cell performance. Therefore, the rib width should be reduced as much as possible within the allowable range to optimize the working performance of the cell.

In order to solve the environmental pollution problem caused by winter heating of rural residential building in northern of China, in this paper a biomass gasification (BG)-solid oxide fuel cell (SOFC) combined heat and power (CHP) system has been establishedand numerically investigated. Taking a rural village around Xi’an which is an ancient city and located at central of northern China as the study object, according to heat and electricity output of the system and the heating and electrical load characteristics of the residential building of village, the energy saving ratio and economical efficiency of the CHP system under three different operation schemes compared with the traditional energy system have been analyzed. The results show that the operation scheme for heating designated rooms in rural buildings and meeting the average heat demand of users is the most energy-efficient and economical way. The primary energy saving rate and annual cost saving rate can reach 18.0% and 10.3%, respectively. When the user’s heat and power load demand is clear, the closer the system’s output heat and power ratio to the user’s heat and power load ratio, the more significant the system’s energy saving effect.