Experimental and computational analyses of a photovoltaic module cooled with an optimized converging channel absorber

Abstract

The electrical performance of photovoltaic (PV) modules under concentrated illumination significantly declines due to the substantial increase in the module's average temperature, especially in areas with elevated ambient temperatures and high levels of solar radiation, such as the Gulf region. Therefore, implementing efficient thermal management to these modules is required for achieving a lower operating temperature, longer lifespan, higher electrical energy output, and harnessing low-grade thermal energy. Converging absorbers are commonly used in PV module's cooling. However, the optimized design for these absorbers is rarely explored. This study proposes an integrated framework combining outdoor experimental testing, computational modeling, and desirability optimization through response surface methodology (RSM) to fill this gap. This integrated framework is employed to statistically evaluate the impact of the converging channel outlet height (H_out, ranging from 3 mm to 17 mm), cooling fluid velocity (from 0.007 to 0.01 m/s), adhesive material thermal conductivity (from 0.14 to 3.7 W/m·K), and cooling water inlet temperature (25 to 35 °C) at a solar concentration ratio of 3 Suns on various PV module responses. Five responses including module temperature, module temperature non-uniformity, thermal power, net electrical power, and entropy generation rate are evaluated at these ranges of the design factors. Predictive models for these five responses are developed with high coefficients of determination (R²). An analysis of variance is performed to identify the most significant factors and interactions influencing each response. Various optimization scenarios for the responses are explored. Among these, maximizing the thermal and electrical generated power can be attained by using a converging channel with H_out of 3 mm, inlet velocity of 0.0084 m/s, inlet temperature of 20 °C, and adhesive thermal conductivity of 2.94 W/m·K.