Nanoparticles and metal foams for heat transfer enhancement of phase change materials: A comparative experimental study

Abstract

This paper presents an experimental work addressing the low thermal conductivity of phase change materials (PCMs), which is a major challenge associated with PCMs, when used as thermal energy storage solutions. This study experimentally compares the effectiveness of using copper oxide nanoparticles and copper metal foams, together and separately, for improving the performance of a selected PCM (RT44HC) during melting and solidification processes and for different heat transfer configurations. Four samples of pure PCM (as the base case), PCM-nanoparticle, PCM-metal foam, and PCM-nanoparticle-metal foam were tested. Two types of melting experiments were conducted: at constant temperature and with constant heat flux heat sources. The solidification experiments were conducted with a constant temperature heat sink. The results of the experiments showed that, compared to the base case of pure PCM, the heat transfer rate inside the PCM-nanoparticle, PCM-metal foam, and PCM-nanoparticle-metal foam composites increased by, respectively, about 13%, 17%, and 24% during melting with constant temperature heat source, about 24%, 26%, and 65% during solidification with constant temperature heat source, and about 7%, 11%, and 12% during melting with constant heat flux heat source. This study also shed light on some other challenges associated with using PCM as well as the role and the practicality of applying above-mentioned thermal techniques in addressing them.