A Thermal Model of a Solar Cooker with Thermal Energy Storage Using Computational Fluid Dynamics
Abstract
In this paper, a thermal model of a solar cooking pot of a parabolic solar cooker is developed and experimentally validated. A thermal energy storage (TES) system is added to allow cooking during hours with no or only a limited amount of sunlight available. Sunflower oil is used both as TES material and cooking fluid. Due to the liquid nature, computational fluid dynamics (CFD) was used to model the fluid flow and heat transfer within the cooking pot. The CFD model was validated with experiments and comparison shows that the model predictions are within experimental uncertainty and variability. At the initial stage of warming up, heat is transferred mostly due to Rayleigh–Bénard convection. With increasing time, the temperature profiles in both the TES and cooking fluid become more and more uniform and at steady state, with an incoming solar power of 4950 W/m2, a temperature of 408K can be reached after 3 hours and 20 minutes of warming up. Keywords: Solar cooker; thermal energy storage; computational fluid dynamics