Thermal analysis and optimization of the emitter in the solar thermophotovoltaic (STPV)

A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically calculated, also the flow field in the emitter cavity and the temperature distribution of the emitter with different inlet conditions are compared. Numerical results show that free convection of the air inside the emitter cavity has great effect on the emitter temperature and may reduce the electricity output of the cells. At last, a new kind of selective film is put forward. Through optimizing the cut-off wavelength of a selective film, radiation loss is further reduced and system efficiency is improved.