Thermal performance of bare and finned tubes submersed in nano-PCM mixture

Abstract

Phase change materials (PCMs) are well accepted as excellent candidates for thermal energy storage and many other important applications. One of their main drawbacks is the poor thermal conductivity which impairs their thermal performance. Many methods were proposed to solve this problem among which fins and nano-PCMs occupy leading positions in terms of efficiency and reliability. In this paper a homebuilt numerical code is used to calculate and compare the numerical predictions of finned and finless tubes submersed in PCM and nano-PCM. For both finned and finless tubes it is found that the increase in the nanoparticles fraction increases the interface position and the interface velocity and decreases the time for complete phase change. For the case of finless tube the addition of 10% of Al2O3 nanoparticles to the PCM and comparing the results with the case of finless tube in pure PCM are found to increase the interface position by 25%. On the other hand, the addition of 10% Al2O3 nanoparticles to the four fins tube and comparing the results with the case finless tube in pure PCM are found to reduce the complete solidification time by 9.1%.