THERMOELECTRIC POWER MODULES.

Silicon-germanium thermoelectric power modules were designed and developed. Modules operated satisfactorily under steady-state and thermal cycling conditions for several thousand hours. These modules were directly exposed to the exhaust gases of various fossil fuels and a number were also tested for shock and vibration. The data in this report will indicate that as a direct result of this research and development effort, a thermoelectric power module was developed which can be used as a building block in the design of thermoelectric power generators. Some effort was spent in obtaining heat transfer characteristics of heat exchangers under free and forced convection conditions. Because of the complex nature of computing the heat transfer properties, a direct analytical solution was not attempted. Much reliance was placed on test results obtained in laboratory experiments and on results reported in literature. The electrical characteristics of the modules were evaluated and an arrangement of either series or series-parallel was determined to satisfy the wide range of voltage and power requirements as specified in the contract requirements. Making use of the developed module design, conceptual 100-watt thermoelectric generator designs are discussed.