Design, development, and analysis of a box type solar cooker with optimally reflecting side walls

Abstract

A novel inclined sidewall box-type solar cooker is constructed, and its performance is evalu-ated. The Opto-geometrical design of the cooker was designed for Surat, a city in India. The design is modified by optimizing the inclination angles of the sidewalls so that an optimal thermal response may be generated by reflecting sun rays from the sidewalls, and the perfor-mance of the solar cooker is enhanced. The optimized sidewall angles due south, due north, due east, and due west are designed to be 67.30, 22.690, 35.440, and 35.440, respectively and side walls are made reflective with reflecting Aluminium sheets. The results are compared with a conventional cooker. The thermal performance of the newly built solar cooker was evaluated, and the merit F1 for no-load circumstances and the merit F2 for various loading conditions were determined. The results show that the maximum plate temperature, the figure of merit F1, and the maximum pot temperature of the newly developed solar cooker with optimally reflecting sidewalls during load test are higher than that of a conventional cooker. The max-imum plate temperature is found to be 760C and 650C in newly designed and conventional solar cookers, respectively. The temperatures are found to be about 16% more from 11:30 pm to 2:00 pm in the newly designed cooker compared to the conventional cooker. The maximum value of Figure of merit F1 is found to be 0.15 and 0.11 in newly designed and conventional solar cookers. The maximum value of Figure of merit F2 is found to be 0.59 and 0.30 in newly designed and conventional solar cookers. The maximum value of pot temperature is found to be 860C and 600C for newly designed and conventional solar cookers, respectively, during the load test, which is about 43% more in the newly designed cooker than the conventional cooker. The highest cooking temperature in the newly designed cooker was maintained at 90 0C for about 2 hours, and that in the conventional cooker was maintained at 60 0C for about 2 hours. In addition, the cooking test demonstrates that the food is thoroughly cooked in the newly built solar cooker, while it was discovered undercooked in the conventional cookerC thickness, respectively without heat recovery. The operating conditions and optimized geo-metric factors, based on result analysis and comparison, are discussed in detail.