Performance enhancement of flat plate cooking unit using novel hook turbulators for indirect solar cooking applications: Numerical and experimental assessment with enviroeconomic analyses

Abstract

Emphasized design modification in cooking units enhanced the performance of solar cooking systems immensely. Motivated by the designs in the literature, an attempt has been made to enhance the performance of a solar-based flat plate cooking unit (FPCU) by incorporating novel hook turbulators. Initially, the thermal behavior of the designed FPCU with and without turbulators was numerically studied using computational fluid dynamics (CFD) analysis. Further, the numerical results were validated by conducting an experimental investigation on the preparation of dosa (Indian rice pancakes). From the CFD results, it was identified that the turbulator inclusion induced uniform temperature distribution and increased core flow velocity, which enhanced the total heat transfer rate by 6.5 % with the penalty of ∼1.64 % increased pressure drop. The experimental results identified that the turbulator inclusion reduced cooking duration by ∼14 % and improved the heat transfer rate, cooking unit and overall system efficiencies by 6.2 %, 2.16 % and 1.55 % respectively, compared to without turbulator configuration. On validation, the numerical and experimental results of FPCU with and without turbulators aligned well with a maximum deviation of ∼6 % for the cooking portion heat transfer coefficient of 100 Wm⁻²K⁻¹. The economic analysis reveals that compared to without turbulator FPCU, the levelized cost of cooking a meal (LCCM) (0.127 $/meal) and levelized cost of cooking energy (LCOE) (0.326 $/kWh) of turbulator-assisted FPCU were reduced by 13.38 % and 5.8 % respectively. The environmental analysis shows that the turbulator-integrated FPCU can mitigate 503.22 kg and 420.17 kg of CO₂/year compared to LPG and electric stoves respectively.