Efficiently exploiting the waste heat in solid oxide fuel cell by means of thermophotovoltaic cell

Through the combination of the current models of solid oxide fuel cells (SOFCs) and thermophotovoltaic cells (TPVCs), a new model of the hybrid device composed of an SOFC, a regenerator, and a TPVC with integrated back surface reflector (BSR) is proposed. Analytical expressions for the power output and efficiency of two subsystems and hybrid device are derived. The relations between the performance of the TPVC and the operating current density of the SOFC in the hybrid device are revealed. The performance characteristics of the hybrid device are discussed in detail. The maximum power output density is calculated. The optimally operating region of the hybrid device is determined, compared with the performance of the SOFC in the hybrid device. The choice criteria of some key parameters are given. Moreover, it is proved that the proposed model can exploit the waste heat produced in SOFCs more efficiently than other SOFC-based hybrid systems. A novel model of the hybrid device composed of a solid oxide fuel cells (SOFC), a regenerator, and a thermophotovoltaic cell (TPVC) with integrated back surface reflector (BSR) is proposed based on the current models of SOFCs and TPVCs. The performances of the hybrid device are optimally analyzed and compared with those of the single SOFC. The advantages of the hybrid device over other SOFC-based hybrid systems are revealed. [Display omitted] •A novel hybrid device exploiting waste heat in solid oxide fuel cells is designed.•The hybrid device includes a solid oxide fuel cell and a thermophotovoltaic cell.•The performances of the hybrid device and the single SOFC are compared.•The optimally operating regions of the hybrid device are determined.•The advantages of the hybrid device over other SOFC-based hybrid systems are shown.