Experimental investigation of the effect of reflectors on thermal performance of box type solar cooker

Cooking consumes a tremendous amount of energy on a regular basis. Solar energy is a very versatile and free energy source that could be used for different applications, including solar cooking. The aim this study is intended to experimentally investigate the effect of different reflectors on the performance of solar box cookers. Box-type solar cooker has been produced and tested with no reflector, aluminum foil reflectors, and mirror glass reflectors cases. Load and no-load tests have been conducted for all three reflector cases and the performances of cookers for each cases reflector have been determined. Several cooking tests was conducted in the outdoors, to investigate the thermal performance of the cooker using water as the absorbing medium. The results of the experimental demonstrate that, the cooker with three side mirror glass reflectors could reach a reasonably high temperature with better efficiency. 1.5 kg of water boiled in 51 min and its second figure of merit was found as 0.533 using mirror glass reflectors. The mirror glass reflector increases the efficiency of the experimental box-type solar cooker by 134% as compared with the cooker having no reflector. The experimental cooker with no reflector did not boil water during the testing period, so it is not recommended for cooking applications; whereas the cooker with the mirror glass reflector has been confirmed to cook most Ethiopian dishes with reasonable performance.