Air conditioner

Abstract

An air conditioner including an outdoor unit, indoor units, and a relay device for connection between the outdoor unit and each of the indoor units. The outdoor unit includes an outdoor heat exchanger, a compressor for pressurizing a refrigerant of or including carbon dioxide, and a first switching member for switching flow direction of the refrigerant through the outdoor heat exchanger. Each of the indoor units includes an indoor heat exchanger and first flow controller in fluid communication between first and second pipe connection ports. The relay device includes second switching members, each of the second switching members selectively connecting the first pipe connection port of a respective indoor unit with the first or second connection end of the outdoor unit.

1 . An air conditioner, comprising:
 an outdoor unit including an outdoor heat exchanger, a compressor for pressurizing a refrigerant of carbon dioxide or a composite having carbon dioxide as a main ingredient, and a first switching member for switching flow direction of the refrigerant through the outdoor heat exchanger, the outdoor heat exchanger, the compressor, and the first switching member being in fluid communication between first and second connection ends;   a plurality of indoor units, each of the indoor units including an indoor heat exchanger and a first flow controller which are in fluid communication between first and second pipe connection ports; and   a relay device including a plurality of second switching members, each of the second switching members selectively connecting the first pipe connection port of a respective indoor unit with either one of the first and second connection ends of the outdoor unit, a first bypass pipe for connection between the second connection end of the outdoor unit and each of the second pipe connection ports of the indoor units, and a second flow controller intervening in the first bypass pipe, wherein when operated in a principally cooling mode, the refrigerants air through t least one of the indoor heat exchangers while remaining in a super critical state, without condensation.   
   
   
       2 . The air conditioner according to  claim 1 , wherein the compressor has a refrigerant delivery port and a refrigerant suction port; and
 the first switching member switches in accordance with operation modes of the air conditioner between first and second conditions, the first condition allowing connection of the refrigerant delivery port to a first end of the outdoor heat exchanger and connection of the refrigerant suction port to the first connection end, the second condition allowing connection of the refrigerant delivery port to the first connection end and connection of the refrigerant suction port to the first end of the outdoor heat exchanger.   
   
   
       3 . (canceled) 
   
   
       4 . The air conditioner according to  claim 2 , further comprising:
 a flow-path selector for guiding the refrigerant from the outdoor heat exchanger to the second connection end and guiding the refrigerant from the first connection end to the refrigerant suction port when the first switching member switches to the first condition, and for guiding the refrigerant from the refrigerant delivery port to the second connection end and guiding the refrigerant from the first connection end to the outdoor heat exchanger when the first switching member switches to the second condition;   a second bypass pipe for fluid communication between the first connection end of the outdoor unit and the first bypass pipe; and   a third flow controller intervening in the second bypass pipe.   
   
   
       5 . The air conditioner according to  claim 4 , wherein the flow-path selector includes
 a first check valve intervening in a first path between the first connection end and the compressor,   a second check valve intervening in a second path between the second connection end and the outdoor heat exchanger,   a third check valve intervening in a third path between the first connection end and the outdoor heat exchanger, and   a fourth check valve intervening in a fourth path between the second connection end and the compressor.   
   
   
       6 . The air conditioner according to  claim 4 , including first and second inter-unit pipes wherein
 the second switching member connects to the first and second connection ends through the first and second inter-unit pipes, respectively; and   the first inter-unit pipe has a pipe wall thickness thinner than that of the second inter-unit pipe.   
   
   
       7 . The air conditioner according to  claim 1 , wherein the first switching member and each of the second switching members are operable independently of other switching members. 
   
   
       8 . The air conditioner according to  claim 1 , wherein the first switching member includes a four-way switching valve. 
   
   
       9 . The air conditioner according to  claim 1 , wherein each of the second switching members includes a three-way switching valve connected to the first and second connection ends of the outdoor unit and the first pipe connection port of a respective indoor unit. 
   
   
       10 . The air conditioner according to  claim 1 , wherein each of the second switching members includes
 a first two-way switching valve connected to the first connection end of the outdoor unit and the first pipe connection port of a respective indoor unit, and   a second two-way switching valve connected to the second connection end of the outdoor unit and the first pipe connection port of a respective indoor unit.