Analysis of the Heat Transfer and Pressure Drop by the Turbulator Having a Non-Uniform Triangular Cross-Section in Air-Type PV/T Collector

Abstract

A photovoltaic/thermal (PV/T) collector prevents a decrease in its electrical efficiency by reducing the temperature of the photovoltaic cell using a fluid. Air-type PV/T collectors use air as the fluid; however, the thermal efficiency of this collector is typically lower than that of other types of collectors. Thus, it is important to improve the thermal efficiency of air-type PV/T collectors. In this study, the heat transfer enhancement and pressure drop caused by a turbulator with a nonuniform triangular cross-section in a PV/T collector were analyzed as one of the methods for improving the thermal efficiency of a collector. The results were obtained using computational fluid dynamics analysis. As a results, the Nusselt number (Nu) and friction factor (f) improved 1.45 and 5.03 times, respectively, compared to those of the smooth air channel. The maximum thermal hydraulic performance parameter, which considered both the enhancement in heat transfer and the increase in pressure drop, was found to be 1.22. In addition, the correlations for Nu and f were developed as functions of the geometric conditions of the turbulator. The results indicated that the developed correlation could predict the simulated values with mean absolute percentage errors of 3.24% and 5.31% for Nu and f, respectively.