Heat exchanger and air-conditioning apparatus including the same

Abstract

A heat exchanger includes: heat transfer tubes; a first header; a second header; and a gas separation pipe. The first header includes a partition wall that partitions an internal space of the first header into spaces including a main flow space and a gas separation space. The partition wall has first openings through which the main flow space and the gas separation space communicate with each other. The gas separation space is located above the main flow space. The gas separation space and the refrigerant pipe are connected by the gas separation pipe.

1 . A heat exchanger that causes heat exchange to be performed between air and refrigerant, the heat exchanger comprising:
 a plurality of heat transfer tubes that extend in a direction of gravitational force, the plurality of heat transfer tubes being arranged apart from each other in a horizontal direction orthogonal to the direction of gravitational force;   a first header connected to the plurality of heat transfer tubes at end portions thereof in an opposite direction to the direction of gravitational force;   a second header connected to the plurality of heat transfer tubes at end portions thereof in the direction of gravitational force; and   a gas separation pipe connecting the first header and a refrigerant pipe through which the refrigerant flows out of the second header when the heat exchanger operates as an evaporator,   wherein   the first header includes a partition wall that partitions an internal space of the first header into a plurality of spaces including a main flow space and a gas separation space,   the partition wall has a plurality of first openings through which the main flow space and the gas separation space communicate with each other,   the gas separation space is located above the main flow space, and   the gas separation space and the refrigerant pipe are connected by the gas separation pipe.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the plurality of first openings are each provided at a higher position than a liquid level of the refrigerant that flows as liquid refrigerant in the main flow space when the heat exchanger operates as an evaporator. 
     
     
         3 . The heat exchanger of  claim 1 , wherein
 the partition wall partitions the internal space of the first header into the main flow space, the gas separation space, and a jet space,   the partition wall has a plurality of second openings through which the main flow space and the jet space communicate with each other, and   each of the plurality of second openings is located at a boundary between gas and a liquid level of the refrigerant that flows as liquid refrigerant in the main flow space and is provided at a position where the second opening does not overlap a plane obtained by projecting a passage cross section of each of the heat transfer tubes in the opposite direction to the direction of gravitational force.   
     
     
         4 . The heat exchanger of  claim 1 , wherein
 the first header includes an upper confluence header and an upper distribution header, the upper confluence header being configured to merge refrigerant streams of refrigerant that flow through some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, into refrigerant, the upper distribution header being configured to distribute the refrigerant in the upper confluence header to remaining ones of the plurality of heat transfer tubes that are other than the some of the plurality of heat transfer tubes,   the second header includes a lower distribution header and a lower confluence header, the lower distributor header being configured to distribute the refrigerant to the some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, the lower confluence header being configured to merge refrigerant streams of the refrigerant that flow from the upper distribution header to the remaining ones of the plurality of heat transfer tubes, into refrigerant,   in the second header, a partition portion is provided between the lower distribution header and the lower confluence header, and   in the first header, the upper confluence header and the upper distribution header share the gas separation space.   
     
     
         5 . The heat exchanger of  claim 1 , wherein
 the first header includes an upper confluence header and an upper distribution header, the upper confluence header being configured to merge refrigerant streams of refrigerant that flow through some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, into refrigerant, the upper distribution header being configured to distribute the refrigerant in the upper confluence header to remaining ones of the plurality of heat transfer tubes that are other than the some of the plurality of heat transfer tubes,   the second header includes a lower distribution header and a lower confluence header, the lower distribution header being configured to distribute the refrigerant to the some of the plurality of heat transfer tubes when the heat exchanger operates as the evaporator, the lower confluence header being configured to merge refrigerant streams of refrigerant that flow from the upper distribution header to the remaining ones of the plurality of heat transfer tubes, into refrigerant,   the upper confluence header includes a plurality of spaces including the gas separation space and the main flow space,   the upper distribution header includes only the main flow space, and   the main flow space of the upper distribution header has a passage sectional area that is smaller than a passage sectional area of the main flow space of the upper confluence header.   
     
     
         6 . The heat exchanger of  claim 1 , further comprising:
 a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air; and   a connection header including a plurality of the first headers and formed as a single body in which the first headers are connected to each other,   wherein   one of a plurality of the second headers is a distribution header configured to distribute the refrigerant to the plurality of heat transfer tubes, and another one of the second headers is a confluence header configured to merge refrigerant streams of refrigerant that flow from the connection header to the plurality of heat transfer tubes, into refrigerant, and   the connection header includes a plurality of spaces including the main flow space and the gas separation space.   
     
     
         7 . The heat exchanger of  claim 1 , further comprising:
 a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air; and   a first connection pipe connecting a plurality of the first headers to each other; and   a second connection pipe connecting a plurality of the second headers to each other,   wherein the first headers each include the main flow space and the gas separation space.   
     
     
         8 . The heat exchanger of  claim 1 , further comprising a plurality of heat exchangers each including the first header, the plurality of heat transfer tubes, and the second header, the plurality of heat exchangers being arranged apart from each other in a flow direction of air,
 wherein the first headers share the gas separation space.   
     
     
         9 . The heat exchanger of  claim 1 , further comprising a gas separation expansion device provided at the gas separation pipe and configured to regulate a flow rate of the refrigerant that flows as gas refrigerant. 
     
     
         10 . An air-conditioning apparatus comprising:
 the heat exchanger of  claim 1 ;   a fan configured to supply the air to the heat exchanger; and   a housing the heat exchanger and the fan.   
     
     
         11 . The air-conditioning apparatus of  claim 10 , wherein
 the heat exchanger includes a bent region that is bent along a corner portion at which two sides of the housing connect with each other as viewed in the direction of gravitational force, and   the gas separation space is provided upstream of the bent region in a flow direction of the refrigerant when the heat exchanger operates as the evaporator.