Research On The Characteristics Of Ground-source Water-cooled Multi-split Air-conditioner System

Ground-source water-cooled multi-split air-conditioner system was developed on the combination of Ground-source heat pump and water-cooled multi-split air-conditioner system. Nowadays it was paid widely attention by domestic and foreign researchers. As a energy-efficient method of using renewable energy as well as it has the advantages of air-cooled multi-split air-conditioner such as convenient and flexible arrangement, energy-saving and easier maintenance. It has a broad application prospect and widely used in actual engineering with the increasingly serious problems of energy crisis.This thesis discussed impact factors of multi-split air-conditioner system of different heating/cooling source. A ground-source water-cooled multi-split air-conditioner system model is set up,which was created with using matlab. The simulation models of compressor, condenser, EEV and evaporator were programmed. As for ground heat exchanger, this thesis took radial heat conduction of soil into consideration, meshed and programmed in the numerical calculation method. It also discussed the frequency, mass flow rate, setpoint of room and intermittent operation mode of ground-source water-cooled multi-split air-conditioner system. Based on an actual building project in Nanjing, focusing on energy saving and economy, it conducted economic analysis of ground-source water-cooled multi-split air-conditioner system and air-cooled multi-split air-conditioner system.The result showed that the COP of water-cooled multi-split air-conditioner system is higher than the COP of air-cooled multi-split air-conditioner system. Meanwhile, as for water-cooled multi-split air-conditioner, studied the difference of cooling water came from ground heat exchanger or cooling tower, the result showed that the application of ground heat exchanger could achieve higher COP.For the ground-source water-cooled multi-split air-conditioner system,the results show that lower frequency, higher indoor temperature, and intermittent operation with get a higher COP. There is a optimum circulating water flow. Analysis results show that soil source water multi-split air-conditioner system has good economy, the initial investment and operation of ground-source water-cooled multi-split air-conditioner system is26%better than air-cooled multi-split air-conditioner system’s, for the design and application of ground-source water-cooled multi-split air-conditioner system provide more guidance.