Design, modelling, energy and exergy analysis of a parabolic cooker

A functional parabolic solar cooker was designed and constructed to serve as an alternate renewable source of energy for cooking and to also reduce the adverse effects of other sources of energy on the environment. The solar cooker was fabricated using cheap, locally sourced available materials in Nigeria. Experimental investigation was carried out on the produced model in Omu-Aran Metropolis, Kwara State, Nigeria in December 2016. Thereafter other investigations were carried out from January to December 2017 and lastly in January 2018 between the hours of 10:00 a.m. to 5:00 p.m. local time for both stagnation and sensible heating, using 2 L of water at every experiment. The average energy and exergy efficiencies of the parabolic cooker were about 39% and 44% respectively. The instability of the energy efficiency occurred as a result of optical and thermal losses from the reflector and pot, as well as the varying environmental conditions. Mathematical expressions were used to calculate the theoretical values of energy and exergy efficiencies using Minitab, while the statistical analysis showed that there was no significant difference between the experimental and predicted results for exergy and energy efficiencies of both cookers at p> 0.05, this validated the design. (C) 2019 Elsevier Ltd. All rights reserved.