Performance Tests of the Solar Steam, Inc., 9-M Deep-Dish Solar Concentrating Collector

摘要

Thermal and optical data were collected and compared to determine system efficiency and optical accuracy. Mirror reflectance (0.83), receiver absorptance (0.95), and the transmittance factor due to aperture blockage (0.915) gave a rho tau alpha product of 0.72. The beam spread due to the reflector surface was measured to be 19 mrad from off-axis thermal performance and 24 mrad by the Reverse Illumination Method, which is described in detail. The beam spread and concentration ratio combine to give an intercept factor of 0.99 for the 58-cm-diameter receiver and total optical efficiency of 0.71. Thermal performance was measured using temperature increases in the output for various water flow rates. The data were fit using a theoretical model for thermal receiver losses. From this curve the optical efficiency was found to be 0.69 and the stagnation or zero flow temperature of the receiver was estimated to be about 470 exp 0 C. Above 85 exp 0 C output temperature, better performance was predicted when using a 40-cm-diameter receiver. Construction details of the collector are also given. (ERA citation 09:024701)