Cell to Cell Performance Variations within a Stack

Abstract

A one-dimensional single cell model is extended to the case of a stack of cells. The present model uses parallel processors in MS-Windows environment. The parallelization is based on domain decomposition where each cell is represented by a single domain. The scheme is implemented using message passing interface (MPI) where cell-to-cell communication is achieved via exchange of temperature and thermal fluxes between neighboring cells. To solve for the stack, the effective overall resistance of each cell is adjusted to meet the constraint that each cell has the same total current. Cell-to-cell voltage variations resulting from different flow distributions are analyzed. A uniform flow distribution resulted in the highest stack voltage. Redistributing 20% of the fuel mass flow-rate could cause as much as 12.0% variation in cell voltage. The present stack model offers a useful design tool enabling parametric study of planar SOFC stacks, along with an assessment of individual cell performance within a stack.