Solidification behavior of water based nanofluid phase change material with a nucleating agent for cool thermal storage system

•Use of nucleating agent eliminates subcooling in nanofluid phase change material.•Reduction in solidification time of 25% using nanofluid phase change material.•50% of mass solidified in 25% of total freezing duration.•Uniform surface heat flux over long duration in the case of water PCM.

This study aimed to investigate the thermal performance of nanofluid phase change material (NFPCM) for cool thermal energy storage (CTES) system. The NFPCM was prepared by suspending 0.1 wt. % multiwall carbon nanotubes (MWCNT) in deionized water (DI water) along with pseudomonas as a nucleating agent. The experiments were conducted at various surrounding bath temperatures with the NFPCM. The results evidently showed that the freezing duration was reduced by 25% in the case of NFPCM along with the elimination of subcooling compared to that of DI water. Further, the fraction of mass solidified at various time intervals revealed that 50% of phase change material (PCM) was frozen in 25% of the total freezing time for both the water PCM and NFPCM. The enhanced heat transport properties of the NFPCM along with the elimination of subcooling and accelerating charging will be very useful in designing energy efficient CTES system.