Modelling the performance of solar cookers: a case of box cooker from local materials

Abstract

This study evaluated the performance of a solar box cooker made out of locally available materials. A mathematical model, based on the heat transfer equations for the various components of the box cooker was developed and used to simulate the temperature profile inside the box cooker using solar irradiance, wind speed and ambient temperature as the inputs. The model was optimised for performance to determine parameters of the box cooker and then validated using experimental measurements. These dimensions from the model were then used to construct the box cooker which was then tested forits performance under two configurations (load test and no load test). The simulated results where on clear day simulated air temperature peaked at 104 C and simulated water temperature peaked at 98 C. Oncloudy day air temperature peaked at 70 C and simulated water temperature peaked at 55 C. No load test was conducted from 10h00 to 15h00 giving first figure of merit as 0.133 and second figure of merit as 0.53 for load test. Load tests were done for both clear day and on a cloudy day by heating one litre of water from 10h00 to 17h00 while monitoring the temperature profiles for air and water inside the box cooker. (end sentence here). On a relatively clear sky day, measured air temperature reached a maximum value of 112 Cwhile measured water temperature was 95 C, enough for cooking by boiling . On a cloudy day, however, the air temperature peaked at 82 C while water temperature peaked at 65 Cwhich is adequate for warming but not boiling. The experimental results showed good agreement with simulated results implying that the model was able to predict the temperature profile closely to the experimental measurements. These findings underscore the solar box cooker’s viability as a sustainable cooking solution in regions with abundant sunlight. Further improvements in material selection, air gap optimization, and testing across diverse environmental conditions are recommended to enhance performance