The Use of the Taguchi Method with Grey Relational Analysis for Nanofluid-Phase Change-Optimized Parameter Design at a Rooftop Solar Photovoltaic Thermal Composite Module for Small Households

Abstract

This study aims to optimize the process parameters of the nanofluid-phase change-solar photovoltaic thermal (nanofluid-PCM-PV/T) composite module. In particular, the organic paraffin was selected as a phase change material, while water, CuO, and Al2O3 were selected as nanofluids. The TRNSYS 16.0 software was employed to model and analyze the composite module. The Taguchi method with the main effect analysis (MEA), analysis of variance (ANOVA), and the orthogonal table were established to investigate the impact of each control factor on the power generation and heat storage efficiency. Grey relational analysis (GRA) was adopted to obtain the parameters for multi-quality optimization. The result showed that the power generation efficiency in this study was 14.958%, and the heat storage efficiency was 64.764%. Meanwhile, in the conventional PV/T module, the former was 12.74%, and the latter was 34.06%, respectively. Verification results showed that the confidence intervals of both single-quality and multi-quality optimization parameter sets were within 95%. The errors of the results from both theoretical simulation and real testing were smaller than 5%. In the case of a generally small family of four members using electric/water heaters, the rooftop module in this study was more efficient than the typical rooftop PV/T by 25.04%. The former’s investment recovery period was lower than 0.81 years.