Study of employing a thermoelectric generator and an alkali metal thermal electric converter for waste heat recovery of a solid oxide fuel cell

Abstract

Although solid oxide fuel cell is an appropriate candidate in the power generation sector, its high waste heat is a problem that should be managed to convert it into a positive feature. Accordingly, this study suggests a novel system for an efficient waste heat recovery of solid oxide fuel cell. Hence, the solid oxide fuel cell is coupled with a thermoelectric generator and an alkali metal thermal electric converter, where the alkali metal thermal electric converter recovers the waste heat of the solid oxide fuel cell, then the thermoelectric generator is used to recover the waste heat of alkali metal thermal electric converter. The plant's performance is evaluated against the current density to indicate the feasibility of the integrity, the optimum current density range, and the maximum current density corresponding to the best productivity of the scheme. Furthermore, eight different parameters are considered to assess the scheme's sensitivity. SOFC operating temperature, average pore diameter, proportional coefficient, TEG temperature, and temperature-independent exchange current coefficient positively influenced the evaluated variables. The highest power density is 10005 W/m 2 at the maximum current density of 13066 A/m 2 resulting in energetic and exergetic efficiencies of 43.30 % and 46.67 %, correspondingly.