The study of heat transfers and thermal performance of different types of solar box cookers

Solar fireplaces are important in remote areas with abundant solar radiation, they are a sustainable and environmentally friendly alternative to traditional cooking methods as they do not emit toxic gases. This study aims to experimentally compare solar box cookers of different designs, materials, and features to understand heat transfer and thermal performance to improve overall efficiency. Four different cases with different materials and features of the box structure are studied: Case 1 - non-tinted wooden sides, case 2 - black tinted wooden sides, case 3 - box with glass sides, and Case 4-black tinted wooden sides and coated inside with aluminum foil. Two designs are compared for each case- one with a front flat mirror and one without. All solar fireplaces consist of an inclined glass facing at an angle to the latitude of Baghdad and a base with black fins. The experiments lasted for three months in various weather conditions including cold, hot, dusty, and sunny days in southern Baghdad, Iraq, positioned at Latitude north and longitude East. Factors such as the intensity of incident radiation, wind speed, and ambient air temperature are taken into account during the cooking period. The results indicate that the third glass-sided box achieved the highest thermal efficiency of 93.7% after 120 minutes. The rice was fully cooked in just 97 minutes, the quickest time ever seen with this type of solar cooker, and it had a thermal efficiency of 88%. The fourth box, lined with aluminum foil inside, succeeded the third book with Rice reaching ripeness at 110 minutes with an 80.5% efficiency.