Air conditioner and indoor unit

Abstract

An air conditioner includes: an outdoor unit; a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe; an indoor unit; a gas-side shutoff valve; a refrigerant sensor; and a controller. The indoor unit is connected to the outdoor unit via the liquid-refrigerant and gas-refrigerant connection pipes, is arranged in an air-conditioning target space, and includes: an indoor heat exchanger that performs heat exchange between a refrigerant circulated between the indoor unit and the outdoor unit via the liquid-refrigerant and gas-refrigerant connection pipes and air sent to the air-conditioning target space; an indoor expansion valve that decompresses the refrigerant; a heat-exchange-side indoor liquid-refrigerant pipe that connects a liquid side of the indoor heat exchanger to the indoor expansion valve; and a connection-side indoor liquid-refrigerant pipe that connects the indoor expansion valve to the liquid-refrigerant connection pipe.

1 - 12 . (canceled) 
     
     
         13 . An air conditioner comprising:
 an outdoor unit;   a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe;   an indoor unit that:
 is connected to the outdoor unit via the liquid-refrigerant connection pipe and the gas-refrigerant connection pipe, 
 is arranged in an air-conditioning target space, and 
 includes:
 an indoor heat exchanger that performs heat exchange between:
 a refrigerant circulated between the indoor unit and the outdoor unit via the liquid-refrigerant connection pipe and the gas-refrigerant connection pipe, and 
 air sent to the air-conditioning target space; 
 
 an indoor expansion valve that decompresses the refrigerant; 
 a heat-exchange-side indoor liquid-refrigerant pipe that connects a liquid side of the indoor heat exchanger to the indoor expansion valve; and 
 a connection-side indoor liquid-refrigerant pipe that connects the indoor expansion valve to the liquid-refrigerant connection pipe; 
 
   a gas-side shutoff valve that is connected to a gas side of the indoor heat exchanger;   a refrigerant sensor that detects leakage of the refrigerant; and   a controller, wherein   the indoor expansion valve is connected to the connection-side indoor liquid-refrigerant pipe by brazing,   a coating material is disposed over brazing portions of the indoor expansion valve and the connection-side indoor liquid-refrigerant, and   the controller closes the indoor expansion valve and the gas-side shutoff valve based on information from the refrigerant sensor when leakage of the refrigerant is detected.   
     
     
         14 . The air conditioner according to  claim 13 , wherein
 the connection-side indoor liquid-refrigerant pipe includes:
 a first connection-side indoor liquid-refrigerant pipe connected to the indoor expansion valve; 
 a second connection-side indoor liquid-refrigerant pipe connected to the liquid-refrigerant connection pipe; and 
 a filter connected, by brazing, between the first connection-side indoor liquid-refrigerant pipe and the second connection-side indoor liquid-refrigerant pipe, and 
   the coating material is disposed over brazing portions of the filter, the first connection-side indoor liquid-refrigerant pipe, and the second connection-side indoor liquid-refrigerant pipe.   
     
     
         15 . The air conditioner according to  claim 13 , wherein
 the outdoor unit includes an outdoor heat exchanger and a liquid-pressure adjustment expansion valve, and   when the refrigerant is sent from the outdoor heat exchanger to the indoor unit via the liquid-refrigerant connection pipe, the controller controls:
 the liquid-pressure adjustment expansion valve to decompress the refrigerant flowing through the liquid-refrigerant connection pipe to be brought into a gas-liquid two-phase state, and 
 the indoor expansion valve to decompress the refrigerant decompressed by the liquid-pressure adjustment expansion valve. 
   
     
     
         16 . The air conditioner according to  claim 13 , further comprising:
 a plurality of indoor units, wherein   each of the indoor units includes a corresponding gas-side shutoff valve and indoor expansion valve.   
     
     
         17 . The air conditioner according to  claim 16  wherein the controller closes only the indoor expansion valve and the gas-side shutoff valve of the indoor units where leakage of the refrigerant is detected by the refrigerant sensor. 
     
     
         18 . The air conditioner according to  claim 13 , wherein
 the gas-refrigerant connection pipe includes an external shutoff valve unit including the gas-side shutoff valve.   
     
     
         19 . The air conditioner according to  claim 18 , wherein
 the gas-side shutoff valve is connected, by brazing, to:
 an indoor-side gas connection pipe that is connected to a portion of the gas-refrigerant connection pipe on a side of the indoor unit; and 
 an outdoor-side gas connection pipe that is connected to a portion of the gas-refrigerant connection pipe on a side of the outdoor unit, and 
   a coating material is disposed over brazing portions of the gas-side shutoff valve and the outdoor-side gas connection pipe.   
     
     
         20 . The air conditioner according to  claim 16 , wherein
 each of the indoor units includes a corresponding indoor heat exchanger,   the gas-refrigerant connection pipe includes a relay including cooling/heating switching valves that individually switches the indoor heat exchanger of each of the plurality of indoor units between an evaporator or a radiator of the refrigerant,   the cooling/heating switching valve serve as the gas-side shutoff valve, and   the controller closes the indoor expansion valve and the cooling/heating switching valves where leakage of the refrigerant is detected by the refrigerant sensor.   
     
     
         21 . The air conditioner according to  claim 20 , wherein
 each of the cooling/heating switching valves is connected, by brazing, to:
 an indoor-side gas connection pipe that is connected to a portion of the gas-refrigerant connection pipe on a side of the indoor unit; and 
 an outdoor-side gas connection pipe that is connected to a portion of the gas-refrigerant connection pipe on a side of the outdoor unit, and 
   a coating material is disposed over brazing portions of the cooling/heating switching valves and the outdoor-side gas connection pipe.   
     
     
         22 . The air conditioner according to  claim 13 , wherein
 the gas-side shutoff valve is provided in the indoor unit,   the indoor unit further includes:
 a heat-exchange-side indoor gas-refrigerant pipe that connects the gas side of the indoor heat exchanger to the gas-side shutoff valve; and 
 a connection-side indoor gas-refrigerant pipe that connects the gas-side shutoff valve to the gas-refrigerant connection pipe, 
   the gas-side shutoff valve is connected to the connection-side indoor gas-refrigerant pipe by brazing, and   a coating material is disposed over brazing portions of the gas-side shutoff valve and the connection-side indoor gas-refrigerant pipe.   
     
     
         23 . An indoor unit connected to an outdoor unit via a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe and arranged in an air-conditioning target space, the indoor unit comprising:
 an indoor heat exchanger that performs heat exchange between:
 a refrigerant circulated between the indoor unit and the outdoor unit via the liquid-refrigerant connection pipe and the gas-refrigerant connection pipe, and 
 air sent to the air-conditioning target space; 
   an indoor expansion valve that decompresses the refrigerant;   a heat-exchange-side indoor liquid-refrigerant pipe that connects a liquid side of the indoor heat exchanger to the indoor expansion valve; and   a connection-side indoor liquid-refrigerant pipe that connects the indoor expansion valve to the liquid-refrigerant connection pipe, wherein   the indoor expansion valve is connected to the connection-side indoor liquid-refrigerant pipe by brazing, and   a coating material is disposed over brazing portions of the indoor expansion valve and the connection-side indoor liquid-refrigerant pipe.   
     
     
         24 . The indoor unit according to  claim 23 , further comprising:
 a gas-side shutoff valve that is connected to a gas side of the indoor heat exchanger;   a heat-exchange-side indoor gas-refrigerant pipe that connects the gas side of the indoor heat exchanger to the gas-side shutoff valve; and   a connection-side indoor gas-refrigerant pipe that connects the gas-side shutoff valve to the gas-refrigerant connection pipe, wherein   the gas-side shutoff valve is connected to the connection-side indoor gas-refrigerant pipe by brazing, and   a coating material is disposed over brazing portions of the gas-side shutoff valve and the connection-side indoor gas-refrigerant pipe.