Thermal Analysis of a Serpentine tube Absorber Plate Solar Collector System using Experimental and CFD Simulation

Abstract

Solar energy is a promising renewable energy source that can be harnessed through various technologies, including solar collectors. The objective was to evaluate the system's thermal performance and understand the heat transfer mechanisms involved. Experimental analysis was carried out using locally fabricated flat plate solar collector setup, considering solar radiation data collected from the National Centre of Energy and Environment (NCEE), Benin City, Edo State, Nigeria. Using the same data set, ANSYS fluent 2018 version was employed for thermal simulation analysis to determine the flow within a serpentine tube, temperature and heat distribution across the flat plate as well as water temperature at the tube exit point. The model was developed to predict thermal behaviour of the system which in the process had considered the principles and laws of thermodynamics, while also solving the equations of continuity, momentum and energy. Water was assumed to be incompressible and flowing continuously while the flow was steady in nature and characterized by laminar. A significant correlation between the experimental and Computational Fluid Dynamics (CFD) simulated results was observed, as maximum experimental and CFD absorber plate temperatures of 368.64 and 372.98 k, serpentine tube water temperatures of 329.14 and 330.45 k and water outlet temperatures at tube exit of 330 and 329 k were obtained. The minimal temperature differential indicated an improved heat transfer absorber plate solar collector system. During the analysis, the physical and thermal properties of the absorber plate, tube and water were independent of the temperature. Heat loss from the base of the absorber plate bottom and the serpentine tube occurred via convection and depended on wind speed. Hence, adoption of ANSYS fluent is an effective CFD tool that can appropriately simulate thermally related problems in serpentine tube absorber plate solar collector system. The results obtained from both approaches were compared and analysed to validate the CFD model and gain insights into the system's performance.