The nonisothermal two‐phase model based on mixed convection in passive μDMFC

Abstract

During the working process of passive microdirect methanol fuel cell (μDMFC), the characteristics of inverse movement between two-phase substances are quite distinct from macro gas-liquid inverse movement, including electrochemical reactions, electrical drag, multicomponent diffusion, evaporation, and condensation. Due to the complexity of internal operation system of μDMFC, it is difficult to monitor and analyze dynamic property currently only by experiment. Therefore, in this paper, an integrated and accurate prediction model to explore two-phase transmission is build up, to investigate different effects by varying parameters, and to maximize cell performance. First, the accuracy of the simulation is proved by experimental tests. Then, a comprehensive, two-phase mass transfer model of passive DMFC is established. The methanol concentration, oxygen concentration, cathode and anode flow velocity and pressure distribution, potential distribution, and anode saturation distribution are studied. Moreover, a nonisothermal model considering the natural convection in the anode is established, the velocity field in the tank, the temperature distribution of the cell, the methanol distribution, and the temperature distribution on the anode catalyst layer is optimized. The research results can provide accurate theoretical support for fuel cell internal component preparation and μDMFC portable applications. K E Y W O R D Sgas-liquid inverse movement, microdirect methanol fuel cell, nonisothermal model