Design And Optimization Of Micro-Thermo-Photovoltaic System

Micro-TPV (thermo photovoltaic) system release chemical energy in combustor though combustion process. The chemical energy will convert into thermal radiation using emitter. At last the photoelectric cell will convert the thermal radiation into electrical energy. Micro-photovoltaic is widely studied because the high theory efficiency and power density. Currently the micro-photovoltaic generator faces the problem of low efficiency in photo-voltage cell and lack of sufficient study in overall research. In this paper, a design of micro-photovoltaic system is presented. Overall studied in this system was done. Finally, optimization on the photoelectric of system was done to improve the efficiency of the MTPV system.Base on the theory of thermal radiation, heat transfer, optical reflection and refraction, combustor, heat radiator and optical filter was designed. A mathematical model was made to analyze the performance of the system. In this paper, comparison of different parameter and design of components such as photoelectric cell fuel, material used in emitter, combustor, optical filter, thermal radiator and output circuit has been done. In the project, Gallium Antimony, GaSb photoelectric cell is selected as photoelectric convertor, Hydrogen is selected as fuel, stainless was selected as material of combustor and fin was used for heat transfer. A DC/DC convertor was designed so that the electrical output is in the magnitude of 5V and 1A. Through component fabrication and purchasing, a thermal photoelectric system was assembled. Based on the thermal photoelectric system, experiments were done in studying the effect of different parameter such as the thickness of combustor wall, Hydrogen flow rate, air and hydrogen ratio, the distance between emitter and photoelectric cell and the type of heat transfer method. Experiment result has been verified. The selected set of parameters was 0.4mm of emitter wall thickness, hydrogen flow rate of 6m/s, air to hydrogen ratio was 0.9, the distance between emitter was 2 cm,8 layers of Si/SiO2 optical filter and fin type for heat radiator.The paper also presents a novel design of quartz heat recuperator which allows the exhaust air to recirculate back to the emitter. Hence, the temperature of the emitter was increased and the combustion efficiency was improved, on the other hand, the temperature of the GaSb photoelectric was reduced. As a result, the overall efficiency increases by 18.5%.