Air conditioner

Abstract

A refrigeration cycle apparatus includes a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, a gas-liquid separator, an indoor heat exchanger, and a refrigerant pipe that connects these components. The gas-liquid separator and a suction side of the compressor are connected by a bypass pipe. The refrigerant pipe includes a riser pipe, a curved pipe, and a down pipe sequentially connected from an upstream side to a downstream side of a flow of refrigerant. The bypass pipe is connected to the riser pipe located upstream of the curved pipe.

1 . An air conditioner comprising:
 a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger;   a refrigerant pipe connected to the compressor, the first heat exchanger, the expansion valve, the second heat exchanger, and the compressor in this order, and configured to allow refrigerant to flow through the refrigerant pipe;   a gas-liquid separator located at a portion of the refrigerant pipe, the portion connecting the expansion valve to the second heat exchanger, the gas-liquid separator being configured to separate the refrigerant flowing from the expansion valve toward the second heat exchanger into gas refrigerant and liquid refrigerant; and   a bypass pipe connected to the gas-liquid separator and configured to direct the refrigerant separated in the gas-liquid separator to the compressor, wherein   the compressor comprises
 a compressor body having a body suction inlet through which the refrigerant is suctioned in, and 
 a suction muffler having a muffler suction inlet connected to the refrigerant pipe, the suction muffler being connected to the body suction inlet of the compressor body, 
   the refrigerant pipe comprises a curved pipe configured to direct the refrigerant to the muffler suction inlet, the refrigerant being directed from a position lower than the muffler suction inlet to a position higher than the muffler suction inlet, and   the bypass pipe is connected to a position of the refrigerant pipe, the position being located away from the muffler suction inlet by a distance that is at least ten times as long as an inner diameter of the curved pipe.   
     
     
         2 . The air conditioner according to  claim 1 , wherein
 the refrigerant pipe comprises a riser pipe that extends upward and configured to direct the refrigerant from a position lower than the muffler suction inlet to an upstream side of the curved pipe, and   the bypass pipe is connected to the riser pipe.   
     
     
         3 . The air conditioner according to  claim 2 , wherein the bypass pipe is connected to the riser pipe to be orthogonal to the riser pipe. 
     
     
         4 . The air conditioner according to  claim 1 , wherein the second heat exchanger comprises
 a first part of the second heat exchanger, and   a second part of the second heat exchanger, the second part being connected in series to the first part of the second heat exchanger and connected to the gas-liquid separator,   in the first part of the second heat exchanger, a heat transfer area per unit length in which the refrigerant flows is defined as a first heat transfer area,   in the second part of the second heat exchanger, a heat transfer area per unit length in which the refrigerant flows is defined as a second heat transfer area, and   the second heat transfer area is set to be larger than the first heat transfer area.   
     
     
         5 . The air conditioner according to  claim 4 , wherein
 the refrigerant pipe has an inner wall surface provided with a ridge formed in a helical shape, and   at least one value of a height of the ridge, a number of the ridges, and a lead angle is set such that the second heat transfer area is larger than the first heat transfer area, the height of the ridge being a height of the ridge from the inner wall surface, the number of the ridges being a number of the ridges provided in a first cross section of the refrigerant pipe, the first cross section being taken along a direction intersecting with an extending direction of the refrigerant pipe, and the lead angle being formed by the extending direction of the refrigerant pipe and an extending direction of the ridge in a second cross section of the refrigerant pipe, the second cross section being taken along the extending direction of the refrigerant pipe.