Performance Analysis of PCM (Phase Change Material) based Thermal Energy Storage Use for Solar-based Cold Room.

Abstract

In today world there is a trend to make the existing system more efficient and less costly. The maximum energy in the world is used to provide cooling in storages, home and public places. To make conventional cold storages more efficient and to use this cooling facility in an urban area where electricity is not available in a continuous manner, solar power based cold storages came into the market. Phase Change Material (PCM )is used in the solar-based cold room to provide backup during no sunshine hours. The present research is carried out to numerically analyse the PCM (mixture of water and ethylene glycol which are mixed in a fixed quantity of 90%V/V and %10V/V respectively) by doing transient analysis with the help of ANSYS Fluent software. The solidification/Melting model commonly known as the enthalpy porosity model is used to observe the solidification behaviour of PCM. The present model is modified by implementing the number of plate fins on the evaporative tube to improve the solidification or charging time of PCM. The numerical results show the improvement of 2.44 % and 12.2 % respectively for 4 fins and 9 fins when the value of heat transfer coefficient was 40 W/m^{2}K and 2.7 % and 7.37 % for the heat transfer coefficient of 30 W/m^{2}K. The solar-based cold room is transiently analysed to analyse the air and temperature distribution inside the storage space. The simulation is carried out for the period of 10 hr and for this period the temperature profile at the centre of the cold room was developed. To store the products different stacks can be used by the users. To observe the variations three different stack design is considered to analyse the variation in air distribution and temperature distribution inside the storage space.