Integration of phase change material in flat plate solar water collector: A state of the art, opportunities, and challenges

Abstract

In the effort of mitigating global greenhouse gas emissions, renewables are crucial. Solar energy is a promising resource to be integrated in residential, commercial, and industrial applications. Flat plate solar collectors (FPSCs) typically harness solar energy. The goal of latest research trend is to enhance solar collector ability to capture irradiation. Phase change material (PCM) can maximize that due to their high latent storage capacity. However, common PCMs have a low thermal conductivity. Nanocomposites can enhance PCM thermal conductivity and thus improves overall system performance. The current review paper analyzes in details the integration of PCM and nanocomposite PCM in the FPSC. It provides thorough analysis of the system modeling. It also provides quantitative results of FPSC performance enhancement. Carbon based nanocomposites and metal foams have shown the greatest enhancement of PCM thermal conductivity. The optimum position for PCM integration is reported to be beneath the heat transfer fluid tubes. The incorporation of PCM guaranteed a longer time period of hot water supply from the collector. Major research contributions were critically assessed. In addition, the detailed review has highlighted scarce experiments done on nanocomposite PCM integration and a significant gap in the optimization analysis of such systems. Furthermore, there is a gap in the economical analysis that is needed for the widespread applications of the considered systems.