Numerical analysis of a small sized water based solar photovoltaic-thermal collector

Abstract

ABSTRACT Large-sized collectors suffer from heat loss from its top due to large aperture plane area. In this work, numerical investigation is performed on a small-sized solar-based photovoltaic thermal water collector using a channel type absorber to analyze its performance under different operating and ambient conditions. A 3D numerical model is developed using COMSOL multi-physics software and the thermal and hydraulic performances of the PV-T collector are carried out. The influence of Reynolds number on the Nusselt number is enumerated for a given operating temperature range and solar radiation level. The variations of PV cell temperature, channel water temperature, thermal and electrical efficiency, exergetic efficiency are studied under different mass flow rates, fluid inlet temperatures, and solar radiations, which majorly control the PV-T performance. It has been observed that with increase of Reynolds number heat transfer rate also increases, and as rate of flow increases from 0.004 kg/s to 0.08 kg/s, the electrical and thermal efficiencies also increase and achieve a maximum 89.96% and 11.47%, respectively. Moreover, uniform temperature distribution has been observed for varying mass flow rates under constant inlet temperature and solar radiation. In addition, a maximum total exergy efficiency of 14.68% is achieved at a mass flow rate of 0.02 kg/s, inlet temperature of 32°C and solar radiation of 900 W/m2. On the basis of the present investigation, a small-sized PV-T collector is recommended for future use as an efficient collector that can provide hot water and also electricity for small-scale domestic or industrial applications.