thermal analysis of the designed cpc and its efficiency improvement by mppt control

The compound parabolic concentrator (cpc) is designed and its optical and thermal analysis is performed in ansys. the cpc sizing and the optimal mass flow rate by maximum power point tracking (mppt) method in matlab are determined. the radiative transfer equation is solved by discrete ordinate (do) and mont carlo (mc) models and the deduced radiative flux divergence is applied as a source term in navier-stokes equations to model heat transfer. results indicate that mc is faster than do with lower computational cost and higher accuracy. the optimal mass flow rate at each time-variable solar radiation is calculated from mppt control and entered as the inlet boundary condition for 3d cfd model. the absorbed useful power by mppt is about 4% higher than the constant mass flow rate case. reduction of the convective heat transfer by locating the evacuated tube collectors inside a cavity leads to 12% more power and 25% temperature enhancement in 3d model with respect to mppt-based analytical results. then, the evacuated collector in a cavity with mppt control has about 16% power gain.