Air conditioner

Abstract

The air conditioner includes refrigerant, a refrigerant circuit, a heat exchanger, and a controller. The refrigerant circuit includes at least a compressor, a condenser and an evaporator, and is configured to circulate the refrigerant the refrigerant. The heat exchanger includes a first flow channel through which the refrigerant that has passed through the condenser flows and a second flow channel through which the refrigerant to be sucked into the compressor flows, and is configured to exchange heat between the refrigerant passing through the first flow channel and the refrigerant passing through the second flow channel. The controller controls the refrigerant circuit so as to cause the degree of superheat of the refrigerant flowing through an outlet of the evaporator to 5 degrees or less.

1 . An air conditioner comprising:
 a refrigerant;   a refrigerant circuit which includes at least a compressor, a condenser and an evaporator, and is configured to circulate the refrigerant;   a heat exchanger which includes a first flow channel through which the refrigerant that has passed through the condenser flows and a second flow channel through which the refrigerant to be sucked into the compressor flows; and   a controller which is configured to control the refrigerant circuit so as to bring a degree of superheat of the refrigerant flowing through an outlet of the evaporator to a target value of 5 degrees or less, wherein   the pressure of the refrigerant passing through the first flow channel is higher than the pressure of the refrigerant passing through the second flow channel,   an inner diameter of a pipe for the first flow channel is smaller than an inner diameter of a pipe for the second flow channel, and   the heat exchanger is configured to perform pressure reduction of the refrigerant passing through the first flow channel and exchange heat between the refrigerant passing through the first flow channel and the refrigerant passing through the second flow channel.   
     
     
         2 - 4 . (canceled) 
     
     
         5 . The air conditioner according to  claim 1 , wherein
 during a cooling operation, the condenser is configured to condense the refrigerant, and the evaporator is configured to evaporate the refrigerant,   the refrigerant circuit further includes a four-way valve that changes a flow direction of the refrigerant passing through the condenser and the evaporator from the flow direction during the cooling operation so as to cause the condenser to evaporate the refrigerant and cause the evaporator to condense the refrigerant during the heating operation,   the first flow channel of the heat exchanger is disposed between the condenser and the evaporator, and the second flow channel of the heat exchanger is disposed between the four-way valve and an inlet of the compressor.   
     
     
         6 . The air conditioner according to  claim 5 , wherein
 the first flow channel includes a first pipe and a second pipe which is disposed in parallel with the first pipe and has an inner diameter smaller than that of the first pipe,   the air conditioner further includes a switching valve to switch the refrigerant to flow through the first pipe or the second pipe, and   the controller controls the switching valve to cause the refrigerant to flow through the first pipe during the cooling operation and cause the refrigerant to flow through the second pipe during the heating operation.   
     
     
         7 . The air conditioner according to  claim 1 , wherein
 the degree of superheat of the refrigerant flowing through the outlet of the evaporator is 0 degrees, and the degree of superheat of the refrigerant to be sucked into the compressor is greater than 0 degrees.   
     
     
         8 . The air conditioner according to  claim 1 , wherein
 the refrigerant has a global warming coefficient of 205 or less, or a saturation temperature of −44.4° C. or more at a standard atmospheric pressure.   
     
     
         9 . The air conditioner according to  claim 1 , wherein
 the refrigerant has a global warming coefficient of 205 or less and a saturation temperature of −44.4° C. or more at a standard atmospheric pressure.   
     
     
         10 . The air conditioner according to  claim 1 , wherein
 the refrigerant includes R32 and R1234yf, and   a mass fraction of R32 in the refrigerant is 30% or less.