공기식 태양광/ 열 집열기 내 비균일 삼각 단면을 갖는 난류 촉진제에 의한 열전달 및 압력강하 성능 분석
Analysis of the Heat Transfer and Pressure Drop by the Turbulator Having a Non-Uniform Triangular Cross-Section in Air-Type PV/T Collector
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A photovoltaic/thermal (PV/T) collector prevents a decrease in its electrical efficiency byreducing the temperature of the photovoltaic cell using a fluid. Air-type PV/T collectors use airas the fluid; however, the thermal efficiency of this collector is typically lower than that of othertypes of collectors. Thus, it is important to improve the thermal efficiency of air-type PV/Tcollectors. In this study, the heat transfer enhancement and pressure drop caused by a turbulatorwith a nonuniform triangular cross-section in a PV/T collector were analyzed as one of themethods for improving the thermal efficiency of a collector. The results were obtained usingcomputational 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 theenhancement in heat transfer and the increase in pressure drop, was found to be 1.22. Inaddition, the correlations for Nu and f were developed as functions of the geometric conditionsof the turbulator. The results indicated that the developed correlation could predict the simulatedvalues with mean absolute percentage errors of 3.24% and 5.31% for Nu and f, respectively.
Abstract
A photovoltaic/thermal (PV/T) collector prevents a decrease in its electrical efficiency byreducing the temperature of the photovoltaic cell using a fluid. Air-type PV/T collectors use airas the fluid; however, the thermal efficiency of this collector is typically lower than that of othertypes of collectors. Thus, it is important to improve the thermal efficiency of air-type PV/Tcollectors. In this study, the heat transfer enhancement and pressure drop caused by a turbulatorwith a nonuniform triangular cross-section in a PV/T collector were analyzed as one of themethods for improving the thermal efficiency of a collector. The results were obtained usingcomputational 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 theenhancement in heat transfer and the increase in pressure drop, was found to be 1.22. Inaddition, the correlations for Nu and f were developed as functions of the geometric conditionsof the turbulator. The results indicated that the developed correlation could predict the simulatedvalues with mean absolute percentage errors of 3.24% and 5.31% for Nu and f, respectively.
참고문헌 (17)
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