Design and numerical simulation of a solar cooker with aluminium absorber plate

Abstract

Solar energy and its harvesting play a very significant role to reduce dependency on fossil fuels like coal, natural gas etc. In developing countries like India, the energy crises and cost of energy for daily needs like cooking of food can be decreased using solar energy. Cooking through solar energy is free from pollution, completely safe and also it maintains high nutritious values of food during cooking. Before developing a prototype box-type solar cooker model, optimum methodical design is always required. In this present work, the design of a box-type solar cooker has been carried out using fundamental laws and relations of thermodynamics and heat transfer to estimate the absorber plate dimension. The estimation of the absorber plate dimension is based on the mass of water required to be boiled, the boiling temperature of the water, time desired to boil the liquid, incident solar radiation on the absorber plate, ambient air temperature and expected overall solar cooker efficiency. The calculation of incident solar radiation from the sun to the absorber plate has been carried out using the ASHRAE radiation model and the related governing radiation model equations have been solved using an in-house developed code in Python. The radiation calculations are based on geographic location at Ranchi, INDIA (Latitude:23.344315-N, Longitude:85.296013-E, Time zone-UTC + 5:30). Proper selection of material is very essential for the overall performance of a solar cooker. Aluminium plate material with matt finished black colour coating has been chosen as it is the most popular absorber plate material used in solar cookers. To validate the present design for absorber plate dimension and its temperature distribution, the results are compared with the numerical simulation results obtained using ANSYS Fluent software. In the numerical simulation work, the Roseland radiation model, and a standard k-ε RNG turbulence model with Boussinesq approximation have been implemented in the simulation work. The estimated results were validated with the simulated results and found to be within a maximum deviation of 1.2% for the absorber plate temperature. The present developed design will help to estimate the solar cooker dimensions before the prototype development.