Field measurement and analysis on operational performance of air-source heat pump systems in Jiaodong area

Tests the performance of seven air-source heat pump systems in Jiaodong area of Shandong Province. Through measuring the key parameters, calculates the performance parameters of the units and the systems. The results show that the design loads are too large and there are differences between the measured and rated performance coefficients of units for most projects, the measured performance coefficients of system are markedly different from the rated values of units for some certain projects. The actual efficiency values of the pumps are different from the rated ones, and water transfer factors of some projects are significantly low. Analyses the typical operation problems of air-source heat pump systems, including the large proportion of heat loss caused by the bypass flow of the shut-down units, the mismatching of the heat source and the end users, the low efficiency of the distribution system and the poor units control.