Construction, Modeling and Simulation of Solar Box Cooker using Phase Change Materials (PCMs) for enhanced cooking method in Maiduguri, Nigeria

Abstract

Thermal energy storage (TES) systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs) for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. With abundant solar energy that can be tapped in Maiduguri from North East (NE) of Nigeria in average annual insolation of 755W/m2with temperature range as high as 38-45oC the development of more efficient, cost effective and clean sources of energy has been an area of much research interest and technological development to fill the growing gap between energy supply and demand. Three phase change materials (PCMs), namely: Paraffin Wax, Palm Oil and Groundnut Oil were used as latent heat storage material in Solar Box Cookers (SBCs) with a single booster mirror for cooking during the day and at off-sunshine hours in Maiduguri Nigeria. ANSYS 19.0 simulation package was used to develop the SBC geometry and carry out numerical simulation while the Bureau of Indian Standards (BIS) was used to experimentally validate the numerical data. Paraffin Wax SBC F1and F2were found to be 0.13 and 0.44, Palm Oil SBC F1and F2were found to be 0.12 and 0.38 and Groundnut Oil SBC F1and F2were found to be 0.13 and 0.4 respectively qualifying all SBCs to grade ‘A’ based on the BIS evaluation standard. While the energy efficiencies were found to be: for Paraffin Wax SBC as (ɳ) 33%, Palm Oil SBC efficiency (ɳ) was 34%and Groundnut Oil SBC energy efficiency (ɳ) was 32%. The simulated oven temperatures were experimentally validated and were found to agree within 5% error of mean for Paraffin Wax SBC (96oC and 98oC), 7% error of mean for Palm Oil SBC (96oC and 93oC) and 4% error of mean for Groundnut Oil SBC at 94oC and 91oC.