PNNL

Abstract

Energy recovery is gaining importance in various transportation, industrial process, and military applications because of rising energy costs and geopolitical uncertainties impacting basic energy supplies. Various advanced energy recovery/conversion technologies will require high-performance heat transfer characteristics to achieve energy recovery performance targets and requirements. System analysis of thermoelectric (TE) systems quantify potential power output, conversion efficiency, specific power and power flux in a unique, useful format on maximum efficiency – power maps. Lines constant specific power and power flux and their relationship to lines of constant hot side temperature and points of maximum power were demonstrated. Regions of preferred TE design were associated with not only higher conversion efficiency, but higher specific power and power flux that motivates TE conversion designs towards use of microtechnology solutions. Water and He gas microchannel designs are investigated as potential solutions to achieve miniature TE energy recovery systems. Developing high-heat-flux thermal designs using microtechnology are key to enabling miniature energy recovery systems and should occur in parallel with on-going research in advanced energy conversion materials.