Effect of non-uniform temperature distribution on surface absorption receiver in parabolic dish solar concentrator

Abstract

A flat surface absorption receiver was experimentally investigated with a parabolic dish solar concentrator in order to study the effect of receiver temperature distribution on heat gain and losses. The addition of specially designed metal fins in the inner surface of the receiver surface side the receiver transfers the incident heat flux to heat transfer fluid. The receiver surface temperature increased with increase in concentration ratio, intensity of beam radiation, and ambient temperature, but decrease with wind speed. The absorptivity of black coated mild steel of 0.85 and also the 0.15 emissivity of mild steel reduced the heat loss from the surface and improved heat gain to heat transfer fluid. The temperature gradient between the receiver periphery and centre is around 150?C. Fluid flow direction like straight and curved paths have been discussed for effective heat absorption and reduced operational duration. The thermal efficiency and operational duration were determined for a flow rate of 80 litres per hour through the receiver. Water flow though the curved path was observed with improved thermal efficiency of 3.8% and 20% reduction in operational duration when compared to the vertical flow through the receiver at same flow rate.