Optimum operation states and parametric selection criteria of a high temperature fuel cell-thermoradiative cell system

A coupling system composed of a high temperature fuel cell such as a molten carbonate fuel cell (MCFC), a regenerator, and a thermoradiative cell (TRC) is established. The efficiency and power output of the coupling system are analytically derived. The performances of the system are evaluated. The optimum operation states of the system are determined. The optimal selection criteria of some key parameters are provided. It is found that when the MCFC is operated at the temperature of 923 K and the band gap of the TRC equals 0.2 eV, the maximum power output density (MPOD) of the coupling system is approximately 2.020 times of that of a single MCFC and the corresponding efficiency of the coupling system is approximately 1.304 times of that of the MCFC. The percentage improvements of the MPODs of the coupling system and other MCFC-based coupling systems in the existing literatures are compared. The results show that the MCFC-TRC coupling system can exhibit better performance and make use of the waste heat released by the MCFC more effectively in comparison with other MCFC-based coupling systems. Moreover, it is expounded that the TRC is an efficient device which can recycle and utilize the waste heat produced by other high temperature fuel cells such as solid oxide fuel cells and direct carbon fuel cells.