Low Temperature Thermal Energy Storage for Passive Cooling using Lauryl Alcohol

Abstract

Renewable energy technologies gained substantial importance in recent years which reduced the use of conventional hydrocarbon fuels significantly, since they are sustainable, green and environment friendly. Large amount of energy is utilized by buildings especially for cooling purpose. It is estimated that 40 percent of the world’s total energy is used by the buildings, resulting in 33 percent of the greenhouse gas (GHGs) emissions every year. To overcome the excessive energy consumed by the cooling equipment, free cooling of the buildings using latent heat thermal energy storage (LTES) technologies via phase change materials (PCMs) is one of the feasible options to fulfill the energy demand of the building in an economical and efficient way. A “free cooling” technique that uses PCMs as cold accumulators during night time ventilation of buildings. In this concept cold air at night time is consumed to freeze PCM to a lower temperature and this cold energy stored is used during day time. “Lauryl alcohol” encapsulated into aluminium tube placed in a wooden box is used as PCM in experiments for free cooling technique. Air is passed above the tube in a properly designed channel to store and release the energy during charging and discharging. About 160g of lauryl alcohol is used to store 37 kJ and recovered 35 kJ of energy during phase change with heat transfer during charging and discharging is 9.6W and 9.37W respectively. The results indicate good performance of lauryl alcohol for passive/free cooling applications.