Performance characteristics and optimal analysis of a fuel cell-vacuum thermionic generator hybrid system

Abstract

Based on the current models of solid oxide fuel cell (SOFC) and vacuum thermionic generator (VTIG), a general model of a class of an irreversible SOFC-VITG hybrid power system, in which irreversibilities existing in real hybrid system are take into account, is established. Expressions for the efficiency and power output of hybrid power system are analytically derived by the model. By using numerical simulation, the relational curves of the efficiency and power output varying with some important performance parameters of the hybrid system are obtained. The performance characteristics of the hybrid system are presented. The optimum criteria of several important performance parameters are given. The effects of several irreversible loses of the hybrid power system on optimum performance are discussed. The results obtained in this paper can provide some theoretical guidance for the optimization design and operation of practical SOFC-VTIG hybrid power system.