Experimental Study on Characteristic of Thermal Energy Storage Defrosting for Air Source Heat Pump Using Sub-cooling Energy of Refrigerant

Abstract

Abstract: This study is concerned with a thermal energy storage defrosting (TESD) based on reverse cycle defrosting method for air source heat pump (ASHP) using subcooling energy of refrigerant to eliminate frost on surface of outdoor coil. The feasibility of thermal energy storage using sub-cooling energy of refrigerant and defrosting were investigated experimentally. The defrosting performances were compared with a normal 850 W capacity ASHP system standard reverse cycle defrosting (SRCD) method. The results indicate that by the TESD for ASHP using sub-cooling energy of refrigerant method, the system coefficient of performance in heating can be improved due to the sub-cooling of refrigerant outlet of indoor coil, defrosting duration and reheating time can be shortened, and the indoor thermal comfort can be improved when defrosting and re-heating. During defrosting duration, TESD for ASHP using sub-cooling energy of refrigerant method improves discharge and suction pressures by 0.57 MPa and 0.11 MPa, respectively, also shortens defrosting duration and re-heating time by 30.8% and 25% in the tested environment, and reduces defrosting power consumption by 22.8kJ, relative to the SRCD method.

Key words: air source heat pump(ASHP), sub-cooling energy, phase change material, thermal energy storage, defrosting

CLC Number:

TU 831.6

DONG Jian-Kai-1, JIANG Yi-Qiang-1, YAO Yang-1, YAN Ling-2. Experimental Study on Characteristic of Thermal Energy Storage Defrosting for Air Source Heat Pump Using Sub-cooling Energy of Refrigerant[J]. Journal of Shanghai Jiaotong University, 2012, 46(10): 1604-1608.

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