Optimisation analysis by numerical simulation of adding internal fins in photovoltaic/thermal system based on Taguchi method

The fins have become a popular research topic for PV/T（photovoltaic/thermal） systems due to their excellent heat transfer properties. Due to the large number of fin parameters and variables in PV/T systems, numerical simulation remains an important tool for predicting system performance. In this paper, a three-dimensional numerical model of a PV/T system containing an inner finned tube is developed using ANSYS software. Optimisation of the inner fin structure is essential for improving system performance and predicting optimal parameters. In this paper, Taguchi method was used to investigate the effects of four factors, namely, inner fin width, number of cross-sections, height, and number of intervals, on the performance of the PV/T system, the performance of the hydrothermal fluids, and the distribution of the PV cell and outlet temperature. S/N(signal-to-noise) ratio analysis shows that the height and number of inner fins have a significant effect on system performance. Finally, the optimal parameter combinations for the inner fins are obtained. The thermal, electrical, overall, and overall exergy efficiencies were improved by 12.28 %, 1.31 %, 9.33 %, and 2.16 %, respectively, when the width was 0.2 mm, the number of pieces was 8, the height was 2.5 mm, and the number of intervals was 4. Further, this paper investigates the variation of the system under the optimal inner fin structure for four external conditions. The PV cell temperature decreased by 1.95–3.52 K and the outlet temperature increased by 0.31 K-1.41 K over the studied operating range. The results of this study provide new ideas for the structural design and optimisation of PV/T systems.