The effect of PCM layer thickness and coolant mass flow rate on the efficiency of a double-channel photovoltaic/thermal-PCM system: Numerical and artificial neural network analysis

A photovoltaic/thermal (PV/T) system containing a phase change material (PCM) layer located between two parallel air flow channels was numerically studied in the present research. With numerous numerical simulations, the effect of PCM layer thickness (ϕ=5–30 mm) and air mass flow rate (m˙_a=0.0123–0.0368 kg/s) on system efficiency were determined. It was found that from the thermal point of view, it is better to have a smaller thickness of the PCM layer, while from the electrical point of view, the average thickness is more effective. The highest thermal efficiency (22.95–59.42 %) and the highest electrical efficiency (16.05–16.79 %) occurred in ϕ=5 mm and ϕ=20 m, respectively. Also, it was revealed that the increase in m˙_a is associated with an increase in the overall efficiency. Among the examined cases, the highest overall efficiency (39.64–77.66 %) belonged to case of ϕ=5 mm and m˙_a=0.0368 kg/s. After identifying this point, the artificial neural network method was used to determine the relationship that can predict the optimal overall efficiency at different hours and at different m˙_a with an acceptable accuracy.