An Efficient Photon Utilization Radioisotope Thermophotovoltaic Based on Curled Reflectors

For radioisotope thermophotovoltaic (RTPV) to produce higher output power, it is often required that the irradiance incident on the thermophotovoltaic (TPV) cell array be more uniform. However, the irradiance received by each cell of the TPV array is relatively different under the conventional cell array surround structure of RTPV, resulting in a serious overall electrical output mismatch loss and a lower output power utilization rate. Herein, an RTPV with curled reflectors optimized by finite-element method is proposed. It is shown in the simulation results that the irradiation uniformity of the cell array can reach 87.5%, the total output power reaches 88.12 W, which is 39.8% higher than that prior to optimization, and the mismatch loss is reduced by 69.2%. In addition, the impact of the reflectivity of reflectors is also targeted from the perspective of practical applications, and it can still produce higher output power than that of the conventional structure even at reflectivity as low as 70%. Ultimately, the RTPV prototype with reflectors is developed, and the electrical performance is tested to verify the effect of irradiance improvement. Herein, reflectors with positive gain for RTPV are proposed, which provides a new idea for the development of high-efficiency power supplies.

Automated summary

This paper proposes a method to improve the irradiance uniformity issue in radioisotope thermophotovoltaic (RTPV) through optimizing curled reflectors using finite-element method. Simulation results show that with the optimized reflectors, the irradiance uniformity of the cell array can reach 87.5%, the total output power reaches 88.12 W, which is 39.8% higher than before optimization, and the mismatch loss is reduced by 69.2%. In addition, it is found that the proposed structure can still generate higher output power than the conventional structure even at reflectivity as low as 70%. Lastly, a RTPV prototype with reflectors is developed and tested to verify the effect of irradiance improvement. This research provides a new idea for the development of high-efficiency power supplies.