Thermal Energy Storage Unit for Air Conditioning Systems Using Phase Change Material.

摘要

A thermal energy storage unit using salt hydrate material was designed for an off-peak air-conditioning system. The unit is sized for a two ton peak load and a one ton daily average load. Based on the stated characteristics of Na2SO4.NH4Cl.10H2O the unit has a rated capacity of 100,000Btu. The heat transfer surface is a stack of 42horizontal aluminium sheets,spaced one inch apart,with imbedded refrigerant passages. The unit is suitable for use in air conditioning coolness storage systems or in space heating storage systems with suitable choices of materials. A cost comparison between a conventional refrigeration unit and recondensing off-peak units storing thermal energy in water or in phase change materials shows the latter to be the most expensive unit even if the phase change material is obtained at zero cost. Only the lower space requirements justify the continued development effort on phase change materials suitable for air conditioning thermal energy storage.