Measurement of transient temperature distribution behavior of a planar solid oxide fuel cell: Effect of instantaneous switching of power generation and direct internal reforming

Abstract

The transient temperature distribution behavior of a planar, co-flow type anode supported solid oxide fuel cell is experimentally investigated under furnace temperatures of 670 °C, 720 °C, and 770 °C. An in-situ measurement is conducted by using a specially designed cell holder and a high-resolution infrared camera. The single and combined effects of electrochemical reactions and direct internal reforming (DIR) reactions are examined. The transient response of the cell temperature profile to a sudden change in the current density or reforming reaction rate is obtained. The results show the clear increase/decrease in the local temperature owing to the exothermic electrochemical reaction/endothermic reforming reaction. The analysis of the time constant shows that the response of the temperature distribution to a sudden change in the current density is faster than that to a change in the fuel gas composition. The time constant is smaller in the upstream region, indicating that the new steady state is first achieved near the flow inlet and gradually propagates downstream. The maximum temperature gradient along the operating cell is found to be lower under the DIR condition than under the non-DIR condition regardless of the furnace temperature.