Preparation and analysis of novel paraffin based stable nano fluid dispersed with carbon nano tubes as effective phase change material for free cooling applications

Abstract

Free cooling concept will play very important part in the future particularly in buildings. Air conditioners usage which leads to global warming can be partly reduced by using the free cooling concept. The best storage medium for cooling and heating is phase change material. Phase change material can be used effectively due to its energy storage capacity during charging and discharging process. The only disadvantage with phase change material is its low thermal conductivity and many researchers have studied various techniques for heat transfer enhancement and hence to improve the thermal conductivity. The present work aims to prepare a novel nano phase change material consisting of phase change material (Paraffin RT21) dispersed with Multiwall Carbon Nanotube (MWCNT) and to study its thermal and rheological properties. The thermal properties like thermal conductivity and rheological properties like viscosity, shear rate, shear stress and density of the nano fluid for different concentrations of MWCNT were evaluated in presence of surfactant. The result explicates that the efficiency of the nano fluid with MWCNT nano particles are better than the Paraffin RT21. Also the present work will provide an input to design effective thermal energy storage system for free cooling application in buildings.