Waste heat recovery from household biomass gasifier stoves (HBGSs) for thermoelectric generators: Effect of the primary air valve angle

Abstract

Household biomass gasifier stoves (HBGSs) are used in remote areas using natural firewood that is burned in the HBGS for general purposes, such as cooking and warming in winter. The heat dissipation from the walls is assumed to be heat loss. This paper evaluates the electrical performance of thermoelectric generators (TEGs) using heat recovered from the hot walls of an HBGS, considering the effect of three primary air valve angles of 0°, 9°, and 18°. The heat recovered from the HBGS that is electrically transferred through a TEG is assessed. The results showed that the wall heat loss increases with the primary air valve angle of the HBGS. The upper zone near the HBGS gas combustion zone exhibits higher wall temperatures than the middle and lower zones, with a maximum wall temperature of 140°C resulting in an output voltage of 2.55 V. However, the middle and lower zones are also considered as their capacities are consistent with the TEG temperature range. The heat loss from the HBGS is considerably larger than that from other heat sources, and the specific heating area of the heat source is a variable that should be considered to increase the number of TEGs to achieve the desired output values for practical applications. Furthermore, this research serves as a guideline for applying TEGs to recover waste heat from various applications.