Numerical Analysis of Thermal Effects and Thermal Management in Thermophotovoltaic Systems

In this paper, we investigated numerically the thermal and electrical performances of a cylindrical thermophotovoltaic (TPV) system cavity composed of a SiC emitter, four GaSb photovoltaic cells and four heat–reflecting mirrors. Using a Multiphysics coupling between the heat transfer and surface–to–surface radiation domains, we emphasized the importance of the effect of the conductive–convective heat transfer on the photocell surface cooling. SiC emissivity values of 0.8, 0.7, 0.6 and 0.5 were considered during simulations, with heat transfer coefficients h_c of the cooling surface between 100 and 500 W/m²K. An abrupt energy conversion efficiency decrease under a value of 19% was observed when the cell temperature was rising over 375 K under TPV working conditions with radiator emissivity of 0.8 and h_c of 200 W/m²K. By maintaining the radiator temperature at low values (around 1000 K) with a low spectral emissivity of 0.5, an air cooling system with forced convection working at h_c = 200 W/m²K can mitigate the thermal losses inside the PV cells.