In the vapor compression heat pump system, the power consumption of the compressor determines the overall power consumption. If a good compressor control technology can be developed, huge energy costs can be saved. This paper is based on the experimental method research, and develops a heat pump system of variable screw compressor Vi, which uses the modulation Vi to control the compression ratio of the matching system operating conditions, the compressor variable frequency control and the expansion valve opening degree control to optimize the system operation. , the experimental benchmark conditions are established by using the field design maximum hot water outlet temperature of 55 ℃, the properties of R134a refrigerant, and the different compression ratios of each working condition with the compressor modulation Vi and other conditions.
The linear trend results of the experimental study show that when the system compression ratio is less than 3.5, the average adiabatic compression efficiency of Vi2.4 is better than Vi3.0 by about 5.08% and Vi3.5 by about 10.56%; it is better than Vi3.0 by about 2.98% And Vi3.5 about 10.77%; and when the system compression ratio is 4.5, the adiabatic compression efficiency of Vi3.5 is better than Vi2.4 about 7.09% and Vi3.0 about 0.10%, better than Vi2.4 about 11.38% and Vi3.0 is about 9.40%. At 55°C hot water outlet temperature, the power consumption of Vi3.5 compressor is about 2.76% less than that of Vi3.0, and about 7.57% less than that of Vi2.4.
