Thermal performance enhancement of box-type solar cooker: a new approach

Abstract

A comparative experimental study of two box-type solar cookers with different cooking environments was conducted. The first one with natural convection heat transfer-based and the second one with forced convection heat transfer (fan for flow augmentation)-based environment. The experimental results show that the forced convection-based environment remarkably improves the thermal performance of box-type solar cooker. Forced convection-based cooker is able to cook food at much faster rates compared with natural convection-based cooker. This reduces the cooking time considerably. Results of thermal performance tests show (i) stagnation absorber plate temperatures of 133.9°C and 119.3°C and (ii) boiling times of 52 min (3120 s) and 75 min (4500 s) for heating 1 kg of water, for the cooker with and without fan, respectively. The solar cooker performance has been rated using the first figure of merit (F1) on the no-load test and the second figure of merit (F2) on the sensible heat tests. The cooking time was considerably reduced by 30.6%. The tests were carried out on the research unit in Government Engineering College Ajmer, Rajasthan located at 26°27′ N latitude and 74°42′ E longitude in India.