Numerical investigations of advanced volumetric reseiver materials

Kurzfassung

This paper presents the results of a numerical analysis of the mass transport and the heat flow through a volumetric solar receiver as a candidate component for a central receiver system for solar electricity generation. The receiver investigated was an extruded honeycomb structure made out of Silicon carbide. The objective of the study is to investigate the influence of slight geometric changes on to the overall performance of the receiver. The results are compared with those of an experimental study. Two numerical models have been developed. One makes use of the real geometry of the channel (single channel model), the other one considers the receiver to be “porous continuum”, which described with homogenized properties such as permeability and effective heat conductivity. The experimental parameters such as average solar heat flux and mass flow were taken into account in the models as boundary conditions. Various parameters such as the average air outlet temperatures, the temperature distributions and the solar-to-thermal efficiency were used for the comparison. The good correspondence between the experimental and numeric results of the both numeric investigations confirms the usefulness of the approach for further studies.