OpenFOAM solver for 3d modelling of solar thermal volumetric receivers coupled to concentration systems

Abstract

Over the last few years, the use of porous volumetric receivers in concentrated solar power (CSP) plants is being extensively investigated. In this work, a three dimensional solver is developed in OpenFOAM to model the solar radiation absorption, thermal and hydrodynamic performance of porous volumetric receivers coupled to solar concentration systems. The porous structure is assimilated to a continuous semi-transparent medium, and the volume averaged mass, momentum and energy conservation equations are solved using the local thermal non-equilibrium (LTNE) approach [1]. The absorbed solar radiation in the solid matrix structure is modelled by coupling a 3D in-house algorithm based on the Monte Carlo Ray Tracing (MCRT) method [2] with the CFD mesh, while the thermal radiation transfer is described by P1 spherical harmonics method. To test the model, a cylindrical receiver element (5 cm of diameter and 5 cm of height) made of open-cell SiC ceramic foam coupled to a parabolic dish with a concentration ratio of 500 is considered. The global model (MCRT and CFD) is designed to have as input the concentrated solar radiation and angle of incidence fields at the receiver inlet, and the main results are the spatial distributions of the absorbed solar radiation, temperature of the fluid and solid matrix structure and fluid velocity. The thermal efficiency, mean fluid temperature at the outlet and pressure drop across the receiver for the test conditions are 85.46%, 474.22 K and 103.10 Pa, respectively. The solver can be easily adapted to model the performance of porous volumetric receivers in different CSP systems.