Three-pipe multi-split air conditioning system and control method thereof

Abstract

A three-pipe multi-split hot water system, including: an outdoor unit, the outdoor unit including a compressor, an oil separator, a first switching apparatus, a second switching apparatus, a fin heat exchanger, a double-pipe heat exchanger, a compressor heat dissipation module, a plate heat exchanger, a first electronic expansion valve, a second electronic expansion valve, a third electronic expansion valve, and a gas-liquid separator; at least two indoor units, any one of the indoor units including an indoor unit heat exchanger, a fourth electronic expansion valve, and an indoor unit fan; and a hydraulic module, the hydraulic module including a refrigerant-water heat exchanger, a water pump, a water temperature detection sensor, a water flow switch, a solenoid valve, and a fifth electronic expansion valve, where the outdoor unit is connected to any one of the indoor units and to the hydraulic module by a gas pipe and a liquid pipe.

What is claimed is: 
     
         1 . A three-pipe multi-split hot water system, comprising:
 an outdoor unit ( 1 ), the outdoor unit ( 1 ) comprising a compressor ( 11 ), an oil separator ( 12 ), a first switching apparatus ( 13 ), a second switching apparatus ( 14 ), a fin heat exchanger ( 15 ), a double-pipe heat exchanger ( 16 ), a compressor heat dissipation module ( 111 ), a plate heat exchanger ( 17 ), a first electronic expansion valve ( 101 ), a second electronic expansion valve ( 102 ), a third electronic expansion valve ( 103 ), and a gas-liquid separator ( 18 );   at least two indoor units ( 2 ), any one of the indoor units ( 2 ) comprising an indoor unit heat exchanger ( 21 ), a fourth electronic expansion valve ( 22 ), and an indoor unit fan ( 23 ); and;   a hydraulic module ( 3 ), the hydraulic module ( 3 ) comprising a refrigerant-water heat exchanger ( 31 ), a water pump ( 32 ), a water temperature detection sensor ( 33 ), a water flow switch ( 34 ), a solenoid valve ( 35 ), and a fifth electronic expansion valve ( 36 );   wherein the outdoor unit ( 1 ) is connected to any one of the indoor units ( 2 ) and to the hydraulic module ( 3 ) by a gas pipe and a liquid pipe.   
     
     
         2 . The three-pipe multi-split hot water system according to  claim 1 , wherein a liquid-side cut-off valve ( 104 ), a gas-side cut-off valve ( 105 ), and a hydraulic module cut-off valve ( 106 ) are disposed on the outdoor unit ( 1 ), the liquid-side cut-off valve ( 104 ) is connected to a liquid pipe of the indoor unit ( 2 ) and a liquid pipe of the hydraulic module ( 3 ), the gas-side cut-off valve ( 105 ) is connected to a gas pipe of the indoor unit ( 2 ), and the hydraulic module cut-off valve ( 106 ) is connected to a gas pipe of the hydraulic module ( 3 ). 
     
     
         3 . The three-pipe multi-split hot water system according to  claim 1 , wherein the first switching apparatus ( 13 ) and the second switching apparatus ( 14 ) are four-way valves. 
     
     
         4 . The three-pipe multi-split hot water system according to  claim 1 , wherein each of the first switching apparatus ( 13 ) and the second switching apparatus ( 14 ) is provided with an interface A, an interface B, an interface C, and an interface D. 
     
     
         5 . A method for controlling the three-pipe multi-split hot water system according to  claim 1 , wherein the second switching apparatus ( 14 ) and the second electronic expansion valve ( 102 ) are controlled to enable the system to implement at least one mode of cooling, heating, hot water production, and defrosting. 
     
     
         6 . The method for controlling the three-pipe multi-split hot water system according to  claim 5 , wherein when both heating and hot water production are required, the second switching apparatus ( 14 ) is powered on, the fin heat exchanger ( 15 ) operates as an evaporator, and the second electronic expansion valve ( 102 ) is closed. 
     
     
         7 . The method for controlling the three-pipe multi-split hot water system according to  claim 5 , wherein when heating, hot water production, and defrosting are all required, the second switching apparatus ( 14 ) is powered off, and the second electronic expansion valve ( 102 ) is opened. 
     
     
         8 . The method for controlling the three-pipe multi-split hot water system according to  claim 5 , wherein when both cooling and hot water production are required, the fin heat exchanger ( 15 ) operates as a condenser, and the second electronic expansion valve ( 102 ) is closed. 
     
     
         9 . The method for controlling the three-pipe multi-split hot water system according to  claim 5 , wherein when both cooling and hot water production with improved heat exchange efficiency are required, the second electronic expansion valve ( 102 ) is closed. 
     
     
         10 . The method for controlling the three-pipe multi-split hot water system according to  claim 5 , wherein when both cooling and hot water production with an increased degree of superheat at light load are required, the fin heat exchanger ( 15 ) operates as a condenser, and the second electronic expansion valve ( 102 ) is opened.