Comparative evaluation of combustion-driven thermoelectric (TE) and thermophotovoltaic (TPV) power generators from a liquid fueled burner

Abstract

A surge of interest in the combustion-driven TE and TPV power systems are rapidly growing in importance. They offer viable pathway in energy sectors and are expected to constitute a considerable proportion in energy market. However, since both devices are combustion-driven, a physical integration between these devices and a burner requires multiple considerations in terms of thermal as well as electrical characteristics. In this study, a combustion-driven power generation system using TE and TPV modules was developed and operated on various blends of two commonly use liquid fuels; namely kerosene and vegetable cooking oil (VCO). A catalytically inert Al2O3 porous medium was incorporated into a liquid-fuel-fired burner operating on 100 kerosene, 90/10 KVCO, 75/25 KVCO, and 50/50 KVCO. The performance aspects at various fuel-air equivalence ratios were thoroughly assessed with the corresponding temperature profiles, voltage, current, power output, and electrical efficiency. For TE generator, the CO emission was relatively lower at the lean region; however, significant amount was recorded in the rich combustion region. NOx fluctuated between 1 ppm to 4 ppm over the entire range of fuel-air equivalence ratio. For TPV generator, the temperature at the surface of the porous alumina was significantly higher than the developed flame temperature and the temperature at the exit of the burner. The CO emission fluctuated between 220 ppm and 380 ppm in the lean region, but appreciably increased as the fuel-air equivalence ratio was gradually enriched. The values of NOx recorded for TPV power system were noticeably higher compared to TE system, and they were in the range of 6 ppm to 31 ppm.