Thermal analysis of an open cell foam volumetric solar receiver

Abstract

The present work is focused on the analysis of a SiC ceramic foam Volumetric Solar Receiver, a component of the solar tower technology. Using ceramic foams to achieve highly performing solar heat recovery systems is now a certainty. The convective heat transfer between the air and the ceramic foam plays an important role in the optimization of a volumetric air receiver. Also the macroscopic temperature distribution in the receiver is crucial to guarantee its safe and efficient operation. Heat transfer is investigated in a porous volumetric receiver, on which the concentrated solar radiation, coming from the heliostats field, impacts. A new simple two-equation model for the energy equation (Local Thermal Non Equilibrium assumption) is proposed. Governing equations are written with the Volume Averaging Technique (VAT). Numerical simulations are carried out through the commercial code COMSOL Multiphysics. Temperature fields and pressure drops inside the solar receiver, under different boundary and morphological conditions, are presented and discussed. The effect of process parameters on the receiver performance is highlighted.