Multi-split system and control method thereof

• Main Authors: XU YONGFENG, SHU WENTAO, XIONG MEIBING, YANG YUANTAO, WAN YONGQIANG, QIAN XIAOLONG, LI BO
• Format: Patent
• Language: English
• Published: 03.06.2015
• Subjects: AIR-CONDITIONING, AIR-HUMIDIFICATION, VENTILATION, USE OF AIRCURRENTS FOR SCREENING; BLASTING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; HEATING; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; RANGES; REFRIGERATION MACHINES, PLANTS OR SYSTEMS; REFRIGERATION OR COOLING; VENTILATING; WEAPONS

The invention discloses a control method of a multi-split system. The multi-split system comprises an outdoor unit and a plurality of indoor units, wherein each indoor unit comprises an indoor heat exchanger and an electronic expansion valve; the outdoor unit comprises an outdoor heat exchanger, a fourth-way valve, a compressor, a low pressure liquid storage tank and an electromagnetic valve; a first node is arranged between the outdoor heat exchanger and the four-way valve; the electromagnetic valve is connected between the first node and the low pressure liquid storage tank. The control method comprises the following steps: S1, acquiring the return air overheat degree of the compressor; and S2, when the return air overheat degree of the compressor is less than a first preset value and can keep a first predetermined time, adjusting the openness of the electronic expansion valves corresponding to the indoor units of the indoor units in a starting up state so as to prevent a liquid refrigerant from flowing back in the multi-split system. The control method disclosed by the invention can be used for quickly enhancing the return air overheat degree of the compressor so as to reduce the probability of return liquid of the compressor, so that the operating reliability of the system is improved. The invention further discloses the multi-split system.