Simulation-based multiobjective management of transient heating process of solid oxide fuel cell

Abstract

A solid oxide fuel cell (SOFC) needs to be heated to an appropriate temperature (around 600°C) before it is switched to start-up mode. A fast heat-up process, which is naturally of interest, can cause high temperature gradients inside the SOFC and the subsequent problems of cracking and delamination. Therefore, in order for the heat-up process to be efficiently managed, the opposing objectives (heat-up duration and temperature gradient) have to be considered simultaneously. The present study investigates the influences of the type of temperature rise function and the average rate of temperature rise (ARTR) on each objective (heat-up duration and temperature gradient). Beside the simple linear temperature rise function of heating fluid considered in previous studies, some innovative nonlinear functions are also introduced and examined in the present study. The results indicate that the rotated-exponential temperature function with an ARTR of 5 K s⁻¹ and the linear temperature function with an ARTR of 0.1 K s⁻¹ are the best choices in terms of heat-up duration and temperature gradient, respectively. This study also attempts to make a compromise between the two objectives and introduces the rotated-quadratic temperature function with an ARTR of 0.4 K s⁻¹ as a representative trade-off solution.