Experimental investigation of the thermal performance of a parabolic dish concentrating solar collector

Abstract

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.

Thermal performance of a point focus concentrating solar collector comprising a 2000 mm diameter, and a focal length of 665 mm symmetric parabolic dish concentrator covered with reflective aluminum tiles of 0.9 reflectivity and SiC honeycomb volumetric absorber, which use atmospheric air as heat transfer fluid is experimentally investigated. The absorber was tested for two different mass flow rates. This is an attempt to assess the potential of this collector as a component of solar cooker with heat storage, a prototype that has a potential to enable indirect and off-sun cooking. The prototype of a solar cooker under investigation is intended to be used in rural areas (in Mozambique) to satisfy the multiple domestic needs in thermal energy as part of a global effort to mitigate the consequences of one of the severe problems the world face today (desertification and deforestation), some of which are attributed to climate change. Thermal efficiency of the collector was estimated for the two mass flow rates. Preliminary results show that at the target temperature range the collector efficiency remained above 70 % and that the higher the mass flow rate, the lower the temperature of the air leaving the collector.