Thermal behaviour of a multi-cavity volumetric solar receiver: Design and tests results

Abstract After some years of basic studies and design, a prototype of a multi-cavity external flow air (or volumetric) receiver was tested at the Plataforma Solar de Almeria test facility. The absorber consists of a pack of SiSiC 9.0 × 4.8 mm (net) channels with a length of 150 mm with vertical and horizontal walls 5.0 and 1.6 mm thick, respectively. Experiments lasted for 30 days in the summer of 1990 and outlet air temperatures, power transferred to air, and efficiency were recorded as functions of solar incident flux and air flowrate. A good accordance between measured and predicted results was noticed, within the limits of accuracy of the data acquisition system of the facility and of the experimental system. Due to its compactness and despite its low mass, the structural behavior of the receiver was also satisfactory; the most important result was to confirm the validity of the concept and of the physical analysis on which the design is based.