Analysis of Thermal Stability of Direct Methanol Fuel Cell Stack Operation

Abstract

A transient model of temperature distribution in a fragment of a direct methanol fuel cell stack is developed. The fragment consists of a segment of a bipolar plate with the single straight anode channel. Stability analysis of model equations shows that at temperatures below critical , stack operation is thermally unstable: a small increase in temperature increases the local rate of heat production in reactions, which further enhances temperature. At temperatures above critical, stack operation is always stable because of the fast rate of liquid water evaporation, which damps temperature disturbances.