Thermal storage in an air conditioning system with dual energy storage unit

Recovery of condensing heat is one of the important methods for energy saving in air conditioning. This not only increases the energy efficiency, but also reduces peak shaving and power load balancing demands. This paper reports the use of a self-developed phase change material for thermal storage in a dual energy storage air conditioning system. The thermal energy storage material is placed in the heat accumulator of the air conditioning unit. Experiments are carried out in different modes including space cooling and water heating, cool storage and water heating, and space cooling and heat storage. Effects of various factors including coolant flux, heat water flux and fan coil air flow are investigated on the whole system performance. It is found that, in the space cooling and heat storage mode, heat storage has little effect on space cooling, but improves the integrated energy efficiency ratio(IEER)significantly, an indication of energy saving of the air conditioning system. In this mode, the greater the coolant flux and fan coil air flow, the greater the IEER of the system. An IEER of 7.06 has been obtained at a fan coil air flowrate of 1033 m3/h and a coolant flux of 972 L/h.