Abstract: With the development of VRF air conditioning systems, on the premise of ensuring quality, the market has higher and higher requirements for the cost of VRF air-conditioning products. At present, some small-capacity VRF in the market control the refrigeration system by temperature or the method of estimating pressure from saturation temperature, instead of high and low pressure pressure sensors. However, in the actual operation, the system inevitably has abnormal conditions such as vacuuming operation or refrigerant leakage operation caused by the hysteresis of temperature measurement. This paper analyzes the operating state, compares the operating parameters under different refrigerant leakage rate, and puts forward the abnormal control of refrigerant leakage with multi-parameter collaborative participation, which provides control ideas and experimental data for the research of refrigerant leakage.

Key words: VRF air conditioning system, Refrigerant leakage, Protection control