Laboratory Determination of Frosting and Defrosting Losses for a High-Efficiency Air-Source Heat Pump

摘要

Tests were performed to detail system and component performance data, to quantify the dynamic losses, and to seek and evaluate methods for reducing these losses. A high efficiency split-system heat pump was installed in two separate air loops, with one loop housing the indoor unit and the other housing the outdoor unit. Calculations of the heat pump's performance based on air-side measurements were within 3% of that based on refrigerant side measurements. Refrigerant flow rate was measured using a turbine flow meter. Refrigerant temperatures and pressures were measured with thermocouples and pressure transducers connected at various strategic locations in the refrigeration circuit. Electric power consumption for all motors was measured with Thermal-watt converters. Performance of the heat pump was measured under steady-state, dehumidification, and frosting-defrosting conditions with major emphasis placed on the dynamic frosting operation of the system. The study encompassed an evaluation of the system and component performance for ambient temperature levels of 8.3, 4.4, 1.7, -1.1 and -8.3 exp 0 C and for discrete humidity levels ranging from 50 to 90%. (ERA citation 06:028854)