Modeling of heat transfer for energy efficiency prediction of solar receivers

In this article, a new heat transfer model for solar receivers with metal foam is developed for design optimization. The proposed model facilitates analysis of heat transfer processes in terms of forced convection, natural convection, heat conduction and radiation, accurately predicting the energy efficiency and percentage contribution of each form of heat loss. The results show good agreement between the predicted results and the experimental data. Specifically, sensitivity analysis is performed to predict the energy efficiency of solar receivers under different operating conditions. To explore the influence of inlet temperature, a series of simulations under high inlet temperature are carried out, resulting in poorer energy performance and heavier radiant heat loss. Non-radiant heat loss, however, accounts for less than 1.1% of the total energy loss in all cases. The results reveal that reduction of radiant loss is conducive to energy efficiency improvement.