MULTI-SPLIT SYSTEM AND LIQUID RETURN PREVENTION CONTROL METHOD THEREOF

摘要

A multi-split system and liquid return prevention control method thereof. The method comprises the following steps: when the multi-split system is in heating operation, if an outdoor unit (20) receives a defrosting instruction, controlling the multi-split system to switch to a defrosting mode to operate for defrosting (S1); detecting gas exhaust pressure, gas return pressure and gas exhaust temperature of a compressor (21) in real time (S2); after defrosting is completed, sending a defrosting completion signal to a diverter (30) by the outdoor unit (20), controlling the compressor (21) to reduce frequency and a plurality of electric-control valves to open, and controlling any one of the electric-control valves to open and the rest of the electric-control valves to close during reversing of a four-way valve (22), so as to reduce the amount of a refrigerant returned to a low-pressure gas-liquid separator (25); and regulating the number of the open electric-control valves during a preset time according to the gas exhaust pressure, the gas return pressure and the gas exhaust temperature (S3).