Direct methanol fuel cell (DMFC): analysis of residence time behaviour of anodic flow bed

Abstract

This paper studies the residence time behaviour and concentration distribution in a simplified rhomboidal DMFC anode flow bed by 3D numerical flow simulations and by experimental measurements. The rhomboidal DMFC anode flow bed and the applied volume flow are discussed with regard to data given in the literature. Simulations with CFX, based on Finite Volume Method, and MooNMD, based on Finite Element Method, show strongly similar results and the reliability of the computed residence time distributions (RTD) is proved by showing that they depend only slightly on parameters of the numerical schemes applied. The realisation of the RTD and concentration distribution measurements are described. Experimentally obtained RTD results are in good agreement with the numerical simulations. Also, the experimentally obtained concentration distribution inside the anode flow bed is very similar to the computed distribution. By analysing the RTDs and concentration distributions, the obtained results provided evidence of weaknesses of the flow bed design.