Variable refrigerant flow system and control method

A control method of a VRF system, the VRF system comprising:

• a first outdoor unit, the first outdoor unit at least comprising three external interfaces, namely, a gas-side stop valve, a liquid-side stop valve, and a multi-functional pipe stop valve;
• a first indoor unit, two ends of a refrigerant pipeline of the first indoor unit being respectively in communication with the gas-side stop valve and the liquid-side stop valve;
• and
• a replaceable module, one end of a refrigerant pipeline of the replaceable module being in communication with the multi-functional pipe stop valve, and the other end being in communication with the liquid-side stop valve, wherein the replaceable module comprises one or more of a phase-change heat storage module, a hydraulic module, a second outdoor unit, or a second indoor unit;
• wherein the outdoor unit at least comprises three four-way valves:
• a four-way valve I, a four-way valve II, and a four-way valve III;
• wherein an exhaust end of the four-way valve I, an exhaust end of the four-way valve II, and an exhaust end of the four-way valve III are in communication with each other, and are jointly in communication with an exhaust end of a compressor;
• an indoor unit connecting end of the four-way valve I is in communication with the gas-side pipe stop valve;
• an outdoor unit connecting end of the four-way valve II is in communication with the liquid-side pipe stop valve;
• an outdoor unit connecting end of the four-way valve III is in communication with the multi-functional pipe stop valve;
• an air-return end and an outdoor unit connecting end of the four-way valve I, an air-return end and an indoor unit connecting end of the four-way valve II, and an air-return end and an indoor unit connecting end of the four-way valve III are all in communication with each other, and are jointly in communication with a suction end of the compressor;
• wherein after the VRF system is powered on, the following steps are performed:
• detecting the replaceable module in communication with the multi-functional pipe stop valve,
• controlling, in response to that the replaceable module is detected, the VRF system to operate in a mode matching the replaceable module, and
• controlling, when the replaceable module is not detected, the VRF system to operate in a normal mode.