Thermoelectric Generator Design, Performance, and Application

Many of the practical problems that are encountered in building present-day generators are illustrated. A design procedure for free convection air-cooled generators is described. The performance of power thermocouples as a function of junction temperature is discussed and curves illustrating couple efficiency, power output, heat flux and voltage as a function of hot junction temperature are shown. The effects of varying thermocouple length on generator efficiency and generator specific power are shown graphically and methods of predicting generator performance are illustrated for thermoelectric materials of equal figures of merit but different values of thermal conductivity. The paper also discusses free convection heat exchangers and fossil-fuel burners. The thermoelectric generator preformance on a watts-per-pound basis is compared with battery-and gasoline-engine-driven generator performance for specific missions.