The temperature control of chilled water for the central air conditioning systems.

The variable refrigerant flow (VRF) air conditioning systems have been widely used to home air conditioner. The VRF system can provide variable refrigerant flow by changing the speed of compressor for energy saving and more comfortable air conditions. Recent years, the energy saving technique for central air condition system becomes important, and the inverter applied as variable frequency drive control the speed of compressor motor technologies have been applied to central air conditioning systems. The central air conditioning system with the inverter compressor (ICCACS) providing variable refrigerant flow becomes an important solution for energy saving. This study built the central air conditioning systems dynamic model with operation data. The appropriate refrigerant flow is calculated by refrigerating capacity. A PI controller is designed to control the speed of compressor for keeping the temperature of chilled water in command temperature. The energy consumption is investigated under transient and steady processes.