Development of 3-D steady state thermal model of solar PV/T collector with sheet and tube heat exchanger

This work involves the development of 3-D, steady state thermal model of PV with sheet and tube heat exchanger and aims to obtain the three-dimensional temperature distribution of various layers in the PV/T panel for various mass flow rates to identify the areas of hotspots in the PV surface. The computational domain of PV/T simulated for thermal analysis consists of glass cover, EVA, solar cell, EVA, Tedlar, absorber plate and cooling tube. The absorbed solar energy which is dissipated in the form of heat is used as volumetric heat generation boundary condition to solve the heat transfer equations and obtained the average temperature of the PV cell from which the temperature-dependent solar cell efficiency is obtained. Initial simulation is done by considering the volumetric heat generation at 15% cell efficiency from which the average efficiency of the cell is obtained and the governing equations are solved iteratively to obtain the temperature profiles. Simulations are performed for a range of mass flow rates at incident radiation of 1000 W/m² and 35°C ambient temperature. Results indicate a decrease in the panel temperature along the length with increase in mass flow rate due to increase convective heat transfer coefficient. At a mass flow rate of 55 LPH, the electrical efficiency and thermal efficiency are 18.16% and 49.09% respectively. Based on the analysis, it is recommended to cool the PV panel at high mass flow rates to obtain high efficiency and to reduce thermal stresses.