Thermal Performance Comparison and Augmentation of Two Identical Box-Type Solar Cookers Operating in Tropical Climatic Conditions

Abstract

In the present study, experimental studies have been performed to compare the thermal performance of two geometrically identical box type solar (B-T-S) cookers. To carry out this aim, the thermal performance of BTS cooker in terms of figure of merits, namely, first figure of merit (F1) and second figure of merit (F2) are calculated for both cookers as specified by the Bureau of Indian Standards (BIS). At no-load condition (i.e., stagnation test), it is found that first figure of merit for both cookers that is cooker 1 and cooker 2 is around 0.12. This implies that both the cookers are identical in thermal performance. In addition to this, the effect of lugs height, reflector, number of pots, and load on B-T-S cooker performance have also been investigated. From the results and discussion, it is concluded that the use of lugs reduced the heat transfer rate between cooking pot and absorber plate. Further, it is found that the pot content temperature is enhanced by 25.5% and 23.4% by using mirror and aluminum reflector with cooker, respectively. However, it is observed that the performance parameters of B-T-S cooker in terms of F2 increases linearly with the increase of number of cooking pot (with correlation F2 = 0.0316n + 0.2238, where n is the number of pots) and load (correlation as F2 = 0.0451 m + 0.1844, where m is the mass of water in cooking pot) on the pot.