Parametric design criteria of an irreversible vacuum thermionic generator

Abstract

A new model of the vacuum thermionic generator (TIG) including internal and external irreversible heat losses is proposed. The energy balance equations of the cathode and anode of the TIG are used to determine the operating temperatures of two electrode plates. Analytic expressions for the power output and efficiency of the system are derived. The power output and efficiency under different conditions are optimized. The effects of the work functions of electrode materials and the output voltage on the performance of the system are discussed. The optimal regions of several important parameters are determined. The optimum design criteria, which may provide some guidance for the choice of electrode materials and the operation of the TIG, are obtained.