Estimation of Spatial Temperature Distribution in Co-Flow Planar Solid Oxide Fuel Cells

Abstract

Significant temperature distribution has been identified in planar Solid Oxide Fuel Cells (SOFCs) during both steady state and transient operations. In order to ensure the material stability and device protection, the maximum temperature and temperature gradient have to be closely monitored and securely maintained below certain limits. In practical implementation, however, direct measurement of the temperature distribution inside the SOFC is difficult and costly. In this paper, an observer is designed and the corresponding performance is analyzed for estimating the temperature distribution in the co-flow planar SOFC. To facilitate the observer design, we introduce a reduced-order nonlinear SOFC model that is obtained based on the high-order detailed model derived in our previous work. Using three easily accessible measurements, namely the stack voltage and the temperatures of the solid structure at the entrance and exit of the SOFC, the observer designed based on the low order model can effectively estimate the temperature profile during both steady-state and transient operations. Model-based analysis and simulation results are presented to demonstrate the performance of the estimation scheme and to provide design guidelines.