Parametric studies on solidification of phase change material inside a cylindrical container toward achieving optimal energy efficiency

Fifty percentage of the energy consumption inside any building is utilized for space cooling purposes. Energy storage through phase change material (PCM) is a viable option to fulfill the cooling energy requirements. The PCM is usually stored inside multiple containers/packets. However, the PCM's low thermal conductivity is a fundamental problem that delays the solidification time and can be accelerated through the nanoparticle addition and higher heat transfer fluid (HTF) flow rate. The recent advancement in nanoparticles opens an opportunity to enhance the heat transfer characteristics of the PCM. Therefore, a detailed parametric analysis is carried out for the PCM inside a cylindrical container to analyze the impact of thermal conductivity (“k”) enhancement through nanoparticle addition and the external surface heat transfer coefficient (“h”) on the solidification time reduction of the Water and RT21 PCM. It is concluded from the results that while utilizing gaseous HTF, it is better to increase the surface “h” rather than increasing the “k” of the PCM. On the other hand, for liquid HTF, “k” value played a significant role in solidification time reduction than increasing the “h” value. A considerate amount of solidification time reduction is possible through nanoenhanced RT21 and water PCM. This study will help the researchers/engineers design an energy efficient storage material toward achieving sustainability.