Development of A Novel Double Exposure Solar Cooker And Its Comparative Performance With The Conventional Box Type Solar Cooker

摘要

A developed novel solar cooker is introduced and constructed using the locally available materials. The absorber plate is exposed to solar radiation from the top and the bottom sides. A fi'ame work o f parabolic mirror reflector is used to direct the solar radiation onto the lower side of the absorber plate while a plane diffuse reflector is used to direct the solar radiation onto the upper side. This is therefore referred to as double exposure solar cooker. The thermal and cooking performance of the new cooker and the conventional box type solar cooker is extensively investigated and compared. The first and second figures of merit for the double exposure solar cooker were found to 0.17 and 0.48 respectively. While the first and second figures of merits for the conventional box type was found to be 0.11 and 0.22 respectively. Maximum absorber plate and oven air temperature for the double solar cooker are 159.7°C respectively at solar radiation level of 870w/mI. 2 while the maximum absorber plate and oven air temperatures for the conventional type solar cooker obtained are 110°C and 105°C respectively. The time for cooking various food items was between 30 to 58 minutes and 51 to 110 minutes for double exposure and conventional box type solar cooker respectively. Cooking time for various food items was remarkably reduced.