A solar cooker equipped with a bottom parabolic reflector and absorber plate integrated with organic PCM: Mathematical modelling, exergy and economic analyses

The present work proposes mathematical models for different configurations of box-type solar cookers (SBCs) with a tracking-type bottom parabolic reflector (TBPR) integrated with paraffin wax as a phase change material (PCM), aiming to enhance the thermal performance of the solar cookers. Analytical models for the proposed configurations of SBC without TBPR and PCM, SBC with TBPR + without PCM, SBC without TBPR+ with PCM, and SBC with TBPR and PCM, which are denoted as SC1, SC2, SC3, and SC4, respectively, are formulated and validated with the experimental results under different operating and climatic conditions. Exergy and economic analyses for the investigated configurations were conducted. It is found that there is a good agreement between the calculated and measured temperatures of the different elements in the investigated configurations, with a relative percentage difference (RPD) not more than 10 % for most cases. The average values of the adjusted (P) and standard (Ps) cooking powers, at a temperature difference of 50 °C, are 22.19 and 18.20 W, respectively. The utilization efficiency (η_u) of the SC4 solar cooker is higher than that of the SC1, SC2, and SC3 by approximately 32.62 %, 19.24 %, and 4.59 %, respectively. The exergy and economic analyses showed that the SC4 is more efficient than other configurations, with the lowest lifetime cost of cooking a meal of 0.021 $.