The design and experimental analyses on variable refrigerant flow path of outdoor unit
In order to determine the optimal flow path of the heat exchanger in the refrigeration and heating modes,a simulation model of the evaporator/condenser of the outdoor unit of the air conditioner was established,and the heat exchanger simulation model was coupled into the system simulation to analyze the impact of different flow paths on the heat transfer and system performance so as to determine the optimal flow path of the heat exchanger corresponding to the refrigeration and heating modes.The results show that the capacity and performance of the entire system decreases as the number of paths varies in the range of 5 to 20 in cooling mode,while in heating mode,the capacity and performance shows an increasing trend at first and then a decreasing trend as the number of paths increases.The optimal number of paths in cooling mode was 5～7,and in heating mode is 14～16.Based on this,a variable flow path scheme with 7/14 flow paths for outdoor unit operation in cooling/heating mode through check valves and solenoid valves.Experimental results show that the system performance is improved and the annual performance factor(APF)is increased by 5.4%under various test conditions,and the heating capacity is increased by 6.0%at an ultra-low temperature of-15℃and the system performance is increased by 2.8%.The research results can provide reference for researchers in the field of heat exchanger design optimization.
万方数据
维普
