Patent Publication Number: US-11035627-B2

Title: Distributor and heat exchanger

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a U.S. national stage application of International Application PCT/JP2016/081754, filed on Oct. 26, 2016, the contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a distributor and a heat exchanger, and particularly to: a distributor configured to distribute refrigerant to each of a plurality of heat transfer tubes disposed to extend in an up-down direction; and a heat exchanger including the distributor and the plurality of heat transfer tubes. 
     BACKGROUND 
     There are a known horizontal distributor configured to distribute refrigerant to each of a plurality of heat transfer tubes disposed to extend in the up-down direction, and also a known vertical heat exchanger including the horizontal distributor and the plurality of heat transfer tubes. In the vertical heat exchanger, the plurality of heat transfer tubes are disposed to be spaced apart from each other in the first direction extending in the horizontal direction. The conventional horizontal distributor includes a circle pipeline extending in the first direction in order to distribute refrigerant to each of the plurality of heat transfer tubes. 
     Japanese Patent Laying-Open No. 2015-203506 discloses a heat exchanger including: a header formed of a double tube disposed such that the axis direction extends in the horizontal direction; and a flat tube disposed such that the long-side direction extends in the vertical direction. 
     PATENT LITERATURE 
     PTL 1: Japanese Patent Laying-Open No. 2015-203506 
     For the conventional vertical heat exchanger as described above, however, it was difficult to reduce the volume of the horizontal distributor. This is due to the following reasons. Specifically, in the conventional vertical heat exchanger, the inner diameter of the circular tube inside the distributor in the cross section perpendicular to the first direction needs to be set at a value equal to or greater than the inner diameter of each heat transfer tube. Thus, irrespective of whether the heat transfer tube is a circular tube or a flat tube, it is difficult to reduce the volume of the circular tube. 
     Particularly, in the conventional vertical heat exchanger including heat transfer tubes each formed as a flat tube, the proportion of the volume of the horizontal distributor to the entire volume of the vertical heat exchanger is greater by the amount corresponding to reduction of the total volume of the plurality of heat transfer tubes than that in the case of the vertical heat exchanger including heat transfer tubes each formed as a circular tube. 
     When the above-described vertical heat exchanger serves as an evaporator, for example, the horizontal distributor disposed above the heat transfer tubes of the vertical heat exchanger serves as a gas single-phase side horizontal distributor while the horizontal distributor disposed below the heat transfer tubes serves as a two-phase side horizontal distributor. The degree of dryness of the refrigerant flowing through the gas single-phase side horizontal distributor is equal to 1 (see  FIG. 32 ). For example, gas-phase refrigerant having a density of 20 kg/m 3  flows through the gas single-phase side horizontal distributor (see  FIG. 33 ). The degree of dryness of the refrigerant flowing through the two-phase side horizontal distributor is less than 1 (see  FIG. 32 ). For example, gas-liquid two-phase refrigerant having a density of 1200 kg/m 3  flows through the two-phase side horizontal distributor (see  FIG. 33 ). Accordingly, in the conventional vertical heat exchanger including the conventional horizontal distributor having a circle pipeline as a two-phase side horizontal distributor, the volume of the two-phase side horizontal distributor is greater than the total volume of the plurality of flat tubes while the weight of the refrigerant inside the two-phase side horizontal distributor is greater than the weight of the refrigerant inside the plurality of flat tubes (see  FIG. 34  (A)). Particularly when the vertical heat exchanger is applied to an indoor unit of an air conditioner for home use, the vertical heat exchanger has a configuration longer in the horizontal direction than in the up-down direction. Thus, the weight of the refrigerant inside the distribution tube extending in the horizontal direction is significantly greater than the weight of the refrigerant inside the flat tube extending in the up-down direction. 
     In other words, for the above-described conventional vertical heat exchangers, it was difficult to sufficiently reduce the weight of the refrigerant inside the horizontal distributor. Accordingly, it was difficult to sufficiently reduce the weight of the refrigerant in the entire heat exchanger. 
     SUMMARY 
     The present invention has been made in order to solve the above-described problems. A main object of the present invention is to provide: a distributor configured to distribute refrigerant to each of a plurality of heat transfer tubes that extend in the up-down direction and reduced in volume as compared with conventional horizontal distributors; and a heat exchanger including the distributor. 
     A distributor according to the present invention is configured to distribute refrigerant to each of a plurality of heat transfer tubes extending in an up-down direction, the plurality of heat transfer tubes being spaced apart from each other in a first direction crossing the up-down direction. The distributor includes: a first member having a plurality of first through holes spaced apart from each other in the first direction; a second member having a first groove facing each of the plurality of first through holes; and a third member having at least one second groove provided to face at least one of the plurality of first through holes. The first groove extends in the first direction. A first space inside the first groove and a second space inside the at least one second groove are connected to each other through a third space inside each of the plurality of first through holes. The third space is higher in flow path resistance than the first space and the second space. 
     According to the present invention, it becomes possible to provide: a distributor configured to distribute refrigerant to each of a plurality of heat transfer tubes that extend in an up-down direction and reduced in volume as compared with the conventional horizontal distributor; and a heat exchanger including the distributor. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a heat exchanger according to the first embodiment. 
         FIG. 2  is a perspective view of a distributor according to the first embodiment. 
         FIG. 3  is a cross-sectional view taken along an arrow in  FIG. 2 . 
         FIG. 4  is an exploded perspective view of the distributor shown in  FIG. 2 . 
         FIG. 5  is a perspective view of a distributor according to the second embodiment. 
         FIG. 6  is a cross-sectional view taken along an arrow VI-VI in  FIG. 5 . 
         FIG. 7  is an exploded perspective view of the distributor shown in  FIG. 5 . 
         FIG. 8  is a cross-sectional view of a distributor according to the third embodiment, which is perpendicular to the first direction. 
         FIG. 9  is a perspective view of the first member and the third member of the distributor shown in  FIG. 8 . 
         FIG. 10  is a plan view of the third member of a distributor according to the fourth embodiment. 
         FIG. 11  is a plan view showing the positional relation between: a plurality of first through holes and a plurality of fourth through holes in the first member; and a plurality of second through holes in the third member, in the distributor according to the fourth embodiment. 
         FIG. 12  is a plan view showing the positional relation between the plurality of first through holes in the first member and the plurality of second through holes in the third member, in a modification of the distributor according to the fourth embodiment. 
         FIG. 13  is a plan view showing a modification of the third member of the distributor according to the fourth embodiment. 
         FIG. 14  is a plan view of the first member of a distributor according to the fifth embodiment. 
         FIG. 15  is a plan view showing an example of distribution of gas-liquid two-phase refrigerant flowing through a groove in the second member of the distributor according to the fifth embodiment. 
         FIG. 16  is a plan view of the first member of a modification of the distributor according to the fifth embodiment. 
         FIG. 17  is a cross-sectional view of the second member of a distributor according to the sixth embodiment, which is perpendicular to an up-down direction. 
         FIG. 18  is a partial cross-sectional view of the first member and the second member of the distributor according to the sixth embodiment, which is perpendicular to the first direction. 
         FIG. 19  is a cross-sectional view of the second member of a distributor according to the seventh embodiment, which is perpendicular to the up-down direction. 
         FIG. 20  is a plan view of the first member of a distributor according to the eighth embodiment. 
         FIG. 21  is a cross-sectional view of a distributor according to the ninth embodiment, which is perpendicular to the first direction. 
         FIG. 22  is a plan view of the second member of the distributor according to the ninth embodiment. 
         FIG. 23  is a plan view of the first member of the distributor according to the ninth embodiment. 
         FIG. 24  is a plan view of the third member of the distributor according to the ninth embodiment. 
         FIG. 25  is a plan view of the fourth member of the distributor according to the ninth embodiment. 
         FIG. 26  is a cross-sectional view of a distributor according to the tenth embodiment, which is perpendicular to the first direction. 
         FIG. 27  is a plan view of the second member of the distributor according to the tenth embodiment. 
         FIG. 28  is a plan view of the first member of the distributor according to the tenth embodiment. 
         FIG. 29  is a plan view of the third member of the distributor according to the tenth embodiment. 
         FIG. 30  is a plan view of the fourth member of the distributor according to the tenth embodiment. 
         FIG. 31  is a cross-sectional view of a modification of the distributor according to the tenth embodiment, which is perpendicular to the first direction. 
         FIG. 32  is a graph showing the distribution of the degree of dryness in the conventional vertical heat exchanger operating as an evaporator, in which a horizontal axis shows a refrigerant path inside the vertical heat exchanger while a vertical axis shows the degree of dryness in each refrigerant path. 
         FIG. 33  is a graph showing the density distribution in the conventional vertical heat exchanger operating as an evaporator, in which a horizontal axis shows a refrigerant path inside the vertical heat exchanger while a vertical axis shows the density (unit: kg/m 3 ) in each refrigerant path. 
         FIG. 34  (A) is a circle graph showing the weight ratio of refrigerant inside a heat transfer tube, an upper horizontal distributor and a lower horizontal distributor of the conventional vertical heat exchanger exhibiting the distribution of the degree of dryness and the density distribution that are shown in  FIG. 32  and  FIG. 33 , respectively. 
         FIG. 34  (B) is a circle graph showing the weight ratio of gas-liquid two-phase refrigerant flowing through the distributor according to the first embodiment, on the condition that the weight of the gas-liquid two-phase refrigerant flowing through the heat transfer tube is equal to that of the conventional vertical heat exchanger shown in  FIG. 34  (A). 
         FIG. 34  (C) is a circle graph showing the weight ratio of gas-liquid two-phase refrigerant flowing through the distributor according to the third embodiment, on the condition that the weight of the gas-liquid two-phase refrigerant flowing through the heat transfer tube is equal to that of the conventional vertical heat exchanger shown in  FIG. 34  (A). 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The embodiments of the present invention will be hereinafter described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference characters, and the description thereof will not be repeated. 
     First Embodiment 
     &lt;Configuration of Heat Exchanger&gt; 
     Referring to  FIG. 1 , a heat exchanger  300  according to the first embodiment will be hereinafter described. For the sake of explanation, a first direction A, a second direction B and an up-down direction C are employed. In  FIG. 1 , first direction A corresponds to the horizontal direction in which distributor  100  extends. Second direction B corresponds to the horizontal direction and is orthogonal to first direction A. Up-down direction C extends in the vertical direction, for example. First direction A and second direction B are orthogonal to up-down direction C. 
     Heat exchanger  300  includes a distributor  100 , a plurality of heat transfer tubes  200 , a plurality of fins  210 , and a distributor  220 , each of which will be described later. 
     Distributor  100  extends in first direction A. Distributor  100  is disposed below the plurality of heat transfer tubes  200 , the plurality of fins  210  and distributor  220 . Distributor  100  is connected to a refrigerant pipe  201 . 
     The plurality of heat transfer tubes  200  each extend in up-down direction C so as to be spaced apart from each other in first direction A. Each of the plurality of heat transfer tubes  200  may have any configuration and may be formed as a flat tube, for example. Each of the plurality of heat transfer tubes  200  is disposed on an upper surface  100 A (described later) of distributor  100 . Each of the plurality of heat transfer tubes  200  is provided with a plurality of refrigerant paths that are spaced apart from each other in second direction B. The plurality of refrigerant paths in each of the plurality of heat transfer tubes  200  are connected to a second space S 2  through each of a plurality of third through holes  2 B provided on upper surface  100 A of distributor  100 , which will be described later. The plurality of refrigerant paths in each of the plurality of heat transfer tubes  200  are connected to distributor  100 . 
     Each of the plurality of fins  210  is disposed between two heat transfer tubes  200  adjacent to each other in first direction A and connected thereto. Each of the plurality of fins  210  is formed as a corrugated fin, for example. 
     Distributor  220  may be a conventional horizontal distributor, for example. Distributor  220  includes a circular tube, for example. This circular tube is connected to the plurality of refrigerant paths in each of the plurality of heat transfer tubes. Distributor  220  is connected to a refrigerant pipe  221 . 
     &lt;Configuration of Distributor&gt; 
     Then, distributor  100  will be described with reference to  FIGS. 2 to 4 . Distributor  100  mainly includes a first member  1 , a second member  2 , a third member  3 , and a fourth member  4 . First member  1 , second member  2 , third member  3 , and fourth member  4  each are formed of a plate-shaped member, for example. Each of first member  1 , second member  2 , third member  3 , and fourth member  4  has a surface having a relatively large area (which will be hereinafter referred to as a main surface) that is disposed perpendicular to up-down direction C. When first member  1 , second member  2 , third member  3 , and fourth member  4  are seen in up-down direction C, the outline shape of each member has a rectangular shape, for example, in which each long-side direction extends in first direction A. Second member  2 , first member  1 , third member  3 , and fourth member  4  are disposed in this order sequentially from top to bottom. 
     First member  1  is provided with a plurality of first through holes  1 A spaced apart from each other in first direction A. Each of the plurality of first through holes  1 A penetrates through both the above-mentioned main surfaces of first member  1 . The plurality of first through holes  1 A have the same configuration, for example. The hole axis of first through hole  1 A extends in up-down direction C, for example. The planar shape of first through hole  1 A as seen in up-down direction C is a circular shape, for example. First through hole  1 A is smaller in opening area than second through hole  3 A, which will be described later. The total opening area of the plurality of first through holes  1 A is smaller than the opening area of second through hole  3 A, for example. 
     As shown in  FIGS. 3 and 4 , first member  1  is provided with a plurality of fourth through holes  1 B spaced apart from each other in first direction A. Each of the plurality of fourth through holes  1 B penetrates through both the above-mentioned main surfaces of first member  1 . Each of the plurality of first through holes  1 A is spaced apart from each of the plurality of fourth through holes  1 B in second direction B. The plurality of fourth through holes  1 B have the same configuration, for example. The hole axis of each fourth through hole  1 B extends in up-down direction C, for example. The planar shape of fourth through hole  1 B as seen in up-down direction C may be any shape having a long-side direction extending in second direction B and a short-side direction extending in first direction A, and may be an approximately elliptical shape, for example. 
     The inner diameter of fourth through hole  1 B in second direction B is longer than the inner diameter of each of first through holes  1 A in second direction B, and shorter than the length of heat transfer tube  200  in second direction B. The inner diameter of fourth through hole  1 B in first direction A is approximately equal to the inner diameter of first through hole  1 A in first direction A, for example. The hole axis of first through hole  1 A is in parallel to the hole axis of fourth through hole  1 B, for example. 
     As shown in  FIGS. 3 and 4 , second member  2  includes a groove  2 A (the first groove) facing each of the plurality of first through holes  1 A. Groove  2 A is formed to be recessed in one of the above-mentioned main surfaces of second member  2  that faces the plurality of first through holes  1 A. The other main surface of second member  2  that is located on the opposite side of this one of the main surfaces is formed as upper surface  100 A of distributor  100 , which will be described later. 
     Groove  2 A extends in first direction A. Second member  2  includes a bent portion. Groove  2 A is located inside the bent portion. This bent portion is bent such that one part of the main surface of second member  2  faces the other part thereof at a distance from each other in second direction B. Groove  2 A is located inside the bent portion. The opening end of groove  2 A faces downward. 
     The cross-sectional shape of groove  2 A that is perpendicular to first direction A may be any shape, and may be a semicircular shape, for example. The length of the opening end of groove  2 A in second direction B is longer than the inner diameter of first through hole  1 A in second direction B. Groove  2 A is spaced apart from each of the plurality of third through holes  2 B in second direction B. A first space S 1  is provided inside groove  2 A. 
     As shown in  FIGS. 3 and 4 , third member  3  is provided with one second through hole  3 A so as to face each of the plurality of first through holes  1 A. One second through hole  3 A penetrates through both the above-mentioned main surfaces of third member  3 . The hole axis of second through hole  3 A extends in up-down direction C. The planar shape of second through hole  3 A as seen in up-down direction C is a rectangular shape, for example. The inner diameter of second through hole  3 A in first direction A is longer than the inner diameter of second through hole  3 A in second direction B. The inner diameter of second through hole  3 A in first direction A is longer than the inner diameter of first through hole  1 A in first direction A and the inner diameter of fourth through hole  1 B in first direction A. The inner diameter of second through hole  3 A in second direction B is longer than the total sum of the inner diameter of first through hole  1 A in second direction B and the inner diameter of fourth through hole  1 B in second direction B. The inner diameter of second through hole  3 A in second direction B is longer than the length of the opening end of groove  2 A in second direction B. 
     First space S 1  extends in first direction A. Second space S 2  is provided inside second through hole  3 A of third member  3 . Fourth member  4  covers the lower portion of second space S 2 . Second space S 2  faces the plurality of first through holes  1 A and the plurality of fourth through holes  1 B. A third space S 3  is provided inside each of the plurality of first through holes  1 A. First space S 1  and second space S 2  are connected to each other through third space S 3 . In other words, first member  1  provides a partition between first space S 1  and second space S 2 . Third space S 3  is higher in flow path resistance than first space S 1  and second space S 2 . 
     As shown in  FIGS. 3 and 4 , in distributor  100 , second member  2  is configured as an outer member of distributor  100  and has upper surface  100 A of distributor  100 . Upper surface  100 A is a main surface of second member  2  that is located on the opposite side of the above-mentioned one main surface facing the plurality of first through holes  1 A. Upper surface  100 A of second member  2  is provided with a plurality of third through holes  2 B spaced apart from each other in first direction A. Each of the plurality of third through holes  2 B faces second space S 2  through fourth through hole  1 B. The plurality of third through holes  2 B have the same configuration, for example. The hole axis of each third through hole  2 B extends in up-down direction C. The planar shape of third through hole  2 B as seen in up-down direction C has a long-side direction and a short-side direction, for example. The long-side direction of third through hole  2 B extends in second direction B. Each of the plurality of third through holes  2 B is spaced apart from the above-described bent portion in second direction B. The inner diameter of third through hole  2 B in second direction B is longer than the length of heat transfer tube  200  in second direction B. In other words, the inner diameter of third through hole  2 B in second direction B is longer than the inner diameter of fourth through hole  1 B in second direction B. When distributor  100  is seen in up-down direction C, the opening end of each of the plurality of third through holes  2 B is disposed on the outside of the opening end of each of the plurality of fourth through holes  1 B. 
     As shown in  FIG. 3 , the lower end of each of the plurality of heat transfer tubes  200  is introduced into each of the plurality of third through holes  2 B, and is in contact with a part of the upper main surface of first member  1 . In this case, the plurality of refrigerant paths in each of the plurality of heat transfer tubes  200  face second space S 2  through fourth through hole  1 B, but are not covered by first member  1 . 
     As shown in  FIG. 3 , third space S 3  is disposed on the same side of the plurality of third through holes  2 B with respect to second space S 2 . Distributor  100  is provided therein with: a refrigerant path extending downward from first space S 1  through third space S 3  to second space S 2 ; and, on the downstream side of this refrigerant path, a refrigerant path extending upward from second space S 2  through each of the plurality of third through holes  2 B to each of the plurality of heat transfer tubes  200 . 
     As shown in  FIG. 3 , second member  2  serves to caulk first member  1 , third member  3  and fourth member  4 . Second member  2  has a caulking portion  21  formed by bending a plate-shaped member. Caulking portion  21  is bent so as to face, in up-down direction C, the portion having upper surface  100 A and including groove  2 A and the plurality of third through holes  2 B. Caulking portion  21  is in contact with the lower main surface of fourth member  4 . 
     As shown in  FIG. 4 , distributor  100  further includes an inflow portion  8  through which refrigerant flows into first space S 1 . Inflow portion  8  is connected to one end of groove  2 A in first direction A, for example. Inflow portion  8  serves as a joint, for example, to connect one end of groove  2 A in first direction A to an inflow pipe  201 . The other end of groove  2 A in first direction A is covered by a divider  9 . 
     The length (thickness) of first member  1  in up-down direction C may be arbitrarily selected, and may be 0.5 mm or more and 10 mm or less, for example, or may be 1 mm, for example. The length (thickness) of second member  2  in up-down direction C may be arbitrarily selected, and may be 1 mm or more and 10 mm or less, for example, or may be 3 mm, for example. The length (thickness) of third member  3  in up-down direction C may be arbitrarily selected, and may be 1 mm or more and 10 mm or less, for example, or may be 3 mm, for example. The length (thickness) of fourth member  4  in up-down direction C may be arbitrarily selected, and may be 0.5 mm or more and 10 mm or less, for example, or may be 3 mm, for example. 
     &lt;Functions and Effects&gt; 
     In distributor  100 , the refrigerant distributed to each of the plurality of heat transfer tubes  200  flows through first space S 1 , third space S 3  and second space S 2  sequentially in this order. First space S 1  and second space S 2  are partitioned by first member  1  provided with first through hole  1 A. In other words, in distributor  100 , the refrigerant path for spreading refrigerant is divided mainly into: first space S 1  in which refrigerant is spread in first direction A; and second space S 2  in which refrigerant is spread at least in second direction B. Accordingly, each of first space S 1  and second space S 2  may extend only in the direction in which refrigerant needs to be spread, and therefore, may be narrowed in the direction in which refrigerant does not need to be spread as compared with the direction in which refrigerant needs to be spread. Thus, the above-described refrigerant path in distributor  100  can be sufficiently reduced in volume as compared with the refrigerant path in the conventional horizontal distributor. In this way, also when heat exchanger  300  serves as an evaporator and gas-liquid two-phase refrigerant flows through distributor  100 , the refrigerant inside distributor  100  can be sufficiently reduced in weight as compared with the conventional horizontal distributor. Also, the refrigerant in the entire heat exchanger  300  can be sufficiently reduced in weight as compared with the conventional vertical heat exchanger. Thereby, the weight of the refrigerant introduced into the refrigeration cycle apparatus including heat exchanger  300  equipped with distributor  100  is less than the weight of the refrigerant introduced into the refrigeration cycle apparatus including a vertical heat exchanger equipped with a conventional horizontal distributor. Consequently, heat exchanger  300  has less influence upon environments such as global warming by refrigerant than the conventional vertical heat exchanger. 
     Heat exchanger  300  is suitable for the indoor unit of an air conditioner for home use. Heat exchanger  300  may be configured to be longer in first direction A than in up-down direction C. Even by such a configuration, in heat exchanger  300 , the refrigerant path extending in first direction A in distributor  100  is less in volume than the conventional horizontal distributor, so that the refrigerant inside distributor  100  can be reduced in weight as compared with the conventional vertical heat exchanger. 
     The length of first space S 1  in second direction B in distributor  100  may be shorter than the length of the space in the second direction, through which refrigerant flows, in the conventional horizontal distributor, for example. The length of first space S 1  in second direction B can be equal to or greater than the hole diameter of first through hole  1 A and less than the length of each of the plurality of heat transfer tubes  200  in second direction B, for example. The volume of the refrigerant path inside distributor  100  can be set to be approximately 40% of the volume of the refrigerant path inside the conventional two-phase side horizontal distributor formed of a circular tube extending in the first direction, for example (see  FIGS. 34  (A) and  34  (B)). 
     Furthermore, in the conventional horizontal distributor, the long-side direction of the refrigerant path extends in the first direction. Thus, it is difficult to uniformly distribute gas-liquid two-phase refrigerant in the first direction. This is because the gas-phase refrigerant that is relatively low in density in the gas-liquid two-phase refrigerant is less likely to receive inertial force as compared with the liquid-phase refrigerant that is relatively high in density, with the result that the gas-phase refrigerant is less likely to be spread in the first direction corresponding to the long-side direction of the refrigerant path. 
     In contrast, in distributor  100 , the gas-liquid two-phase refrigerant distributed in first space S 1  in first direction A flows through each of the plurality of first through holes  1 A into second space S 2 . Third space S 3  inside first through hole  1 A is higher in flow path resistance than first space S 1 . Thus, the flow of the gas-liquid two-phase refrigerant from first space S 1  to second space S 2  is contracted by the plurality of first through holes  1 A. At this time, the gas-liquid two-phase refrigerant inside first space S 1  may be mixed. Furthermore, third space S 3  inside first through hole  1 A is higher in flow path resistance than second space S 2 . Thus, the refrigerant inside third space S 3  is emitted into second space S 2 . Accordingly, the gas-liquid two-phase refrigerant inside second space S 2  of distributor  100  is more uniformly distributed in first direction A than the gas-liquid two-phase refrigerant inside the conventional horizontal distributor. In other words, distributor  100  can further uniformly distribute gas-liquid two-phase refrigerant to each of the plurality of heat transfer tubes  200  spaced apart from each other in first direction A, as compared with the conventional horizontal distributor. 
     In distributor  100  described above, the gas-liquid two-phase refrigerant having flown into second space S 2  and spread in second direction B may be distributed to each of the plurality of third through holes  2 B having the long-side direction extending in second direction B. Accordingly, distributor  100  can uniformly distribute gas-liquid two-phase refrigerant to each of the plurality of refrigerant paths that are spaced apart from each other in second direction B inside each heat transfer tube  200  inserted into each of the plurality of third through holes  2 B. 
     In distributor  100  described above, third space S 3  is disposed on the same side of the plurality of third through holes  2 B with respect to second space S 2 . Thus, in distributor  100 , the circulation direction of the refrigerant is inverted inside second space S 2 . In other words, the refrigerant having flown from first space S 1  through third space S 3  into second space S 2  is changed in its flowing direction in second space S 2  facing fourth member  4 , and then flows from second space S 2  into third through hole  2 B. Distributor  100  as described above can facilitate spreading of the gas-liquid two-phase refrigerant inside second space S 2 , thereby allowing more uniform distribution of the gas-liquid two-phase refrigerant to each of the plurality of heat transfer tubes  200 . 
     In distributor  100  described above, the inner diameter of third through hole  2 B in second direction B is longer than the length of each of the plurality of heat transfer tubes  200  in second direction B. The inner diameter of fourth through hole  1 B in second direction B is shorter than the length of each of the plurality of heat transfer tubes  200  in second direction B. Each of the plurality of third through holes  2 B faces second space S 2  through fourth through hole  1 B. In this way, the lower ends of the plurality of heat transfer tubes  200  each introduced into a corresponding one of the plurality of third through holes  2 B come into contact with first member  1  provided with the plurality of fourth through holes  1 B. In other word, first member  1  may serve as a stopper for the lower ends of the plurality of heat transfer tubes  200 . In distributor  100 , the inner diameter of fourth through hole  1 B in second direction B may be longer than the length of each of the plurality of heat transfer tubes  200  in second direction B as long as second space S 2  can be maintained. In this case, second member  2  of distributor  100  only has to be fixed to the plurality of heat transfer tubes  200  by an optional method. 
     Distributor  100  includes first member  1 , second member  2 , third member  3 , and fourth member  4 , each of which is formed of a plate-shaped member. Accordingly, the plurality of first through holes  1 A, the plurality of second through holes  3 A, the plurality of third through holes  2 B, and the plurality of fourth through holes  1 B each may be readily formed by press working. Furthermore, second member  2  serves to caulk first member  1 , third member  3  and fourth member  4 . Distributor  100  as described above may be manufactured readily and inexpensively as compared with the conventional horizontal distributor. 
     Second Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, a distributor  101  according to the second embodiment will be described with reference to  FIGS. 5 to 7 . Distributor  101  according to the second embodiment has basically the same configuration as that of distributor  100  according to the first embodiment, but is different therefrom in that third space S 3  is disposed on the opposite side of the plurality of third through holes  7 A with respect to second space S 2 . 
     As shown in  FIGS. 5 to 7 , distributor  101  includes a first member  1 , a second member  2 , a third member  3 , a fifth member  5 , and a seventh member  7 . First member  1 , second member  2 , third member  3 , fifth member  5 , and seventh member  7  each are formed of a plate-shaped member, for example. Each of first member  1 , second member  2 , third member  3 , fifth member  5 , and seventh member  7  has a surface having a relatively large area (hereinafter referred to as a main surface) that is disposed perpendicular to up-down direction C. When first member  1 , second member  2 , third member  3 , fifth member  5 , and seventh member  7  are seen in up-down direction C, the outer shape of each member is a rectangular shape, for example, having a long-side direction extending in first direction A. Seventh member  7 , fifth member  5 , third member  3 , first member  1 , and second member  2  are disposed in this order sequentially from top to bottom. In distributor  101 , seventh member  7  is formed as an outer member. 
     As shown in  FIGS. 6 and 7 , first member  1  has basically the same configuration as that of first member  1  of distributor  100 , but is different therefrom in that the plurality of fourth through holes  1 B are not provided. 
     As shown in  FIGS. 6 and 7 , second member  2  has basically the same configuration as that of second member  2  of distributor  100 , but is different therefrom in that second member  2  is not provided with a plurality of third through holes  2 B and not formed as an outer member, and that the opening end of groove  2 A faces upward. Second member  2  includes a bent portion that is bent downward to form a protruding shape. Groove  2 A is provided inside this bent portion. 
     As shown in  FIGS. 6 and 7 , third member  3  has basically the same configuration as that of second member  2  of distributor  100 . 
     As shown in  FIGS. 6 and 7 , fifth member  5  is provided with a plurality of fifth through holes  5 A that are spaced apart from each other in first direction A. Each of the plurality of fifth through holes  5 A penetrates through both the above-mentioned main surfaces of fifth member  5 . The plurality of fifth through holes  5 A have the same configuration, for example. The hole axis of each fifth through hole  5 A extends in up-down direction C, for example. The planar shape of fifth through hole  5 A in up-down direction C may be any shape having the long-side direction extending in second direction B and the short-side direction extending in first direction A, and may be an approximately elliptical shape, for example. 
     As shown in  FIGS. 6 and 7 , the inner diameter of fifth through hole  5 A in second direction B is longer than the inner diameter of each of first through holes  1 A in second direction B, and shorter than the length of heat transfer tube  200  in second direction B. The inner diameter of fifth through hole  5 A in first direction A is approximately equal to the inner diameter of first through hole  1 A in first direction A, for example. The hole axis of fifth through hole  5 A is in parallel to the hole axis of first through hole  1 A, for example. 
     As shown in  FIGS. 6 and 7 , seventh member  7  is formed as an outer member of distributor  101 , and configured to have an upper surface  101 A of distributor  101 . Upper surface  101 A is a main surface of seventh member  7  that is located on the opposite side of one main surface facing the plurality of fifth through holes  5 A. Upper surface  101 A of seventh member  7  is provided with a plurality of third through holes  7 A spaced apart from each other in first direction A. Each of the plurality of third through holes  7 A faces second space S 2  through fifth through hole  5 A. The plurality of third through holes  7 A have the same configuration, for example. The hole axis of each third through hole  7 A extends in up-down direction C. The planar shape of third through hole  7 A as seen in up-down direction C has a long-side direction and a short-side direction, for example. The long-side direction of third through hole  7 A extends in second direction B. The inner diameter of third through hole  7 A in second direction B is longer than the length of heat transfer tube  200  in second direction B. In other words, the inner diameter of third through hole  7 A in second direction B is longer than the inner diameter of fifth through hole  5 A in second direction B. When distributor  100  is seen in up-down direction C, the opening end of each of the plurality of third through holes  7 A is disposed on the outside of the opening end of each of the plurality of fifth through holes  5 A. 
     As shown in  FIG. 6 , seventh member  7  serves to caulk first member  1 , second member  2 , third member  3 , and fifth member  5 . Seventh member  7  has a caulking portion  71  formed by bending a plate-shaped member. Caulking portion  71  is bent so as to face, in up-down direction C, the portion having upper surface  101 A and provided with a plurality of third through holes  7 A. Caulking portion  71  is disposed so as to face each other in second direction B with the bent portion of second member  2  interposed therebetween. Caulking portion  71  is in contact with the lower main surface of second member  2 . 
     As shown in  FIG. 6 , the lower end of each of the plurality of heat transfer tubes  200  is introduced into each of the plurality of third through holes  7 A to be in contact with a part of the upper main surface of fifth member  5 . At this time, the plurality of refrigerant paths in each of the plurality of heat transfer tubes  200  face second space S 2  through fifth through hole  5 A, and are not covered by fifth member  5 . 
     As shown in  FIG. 6 , first space S 1  is provided inside groove  2 A. First space S 1  extends in first direction A. Second space S 2  is provided inside second through hole  3 A of third member  3 . Third space S 3  is provided inside each of the plurality of first through holes  1 A. First space S 1  and second space S 2  are connected to each other through third space S 3 . In other words, first member  1  provides a partition between first space S 1  and second space S 2 . Third space S 3  is higher in flow path resistance than first space S 1  and second space S 2 . 
     As shown in  FIG. 6 , in distributor  101 , third space S 3  is disposed on the opposite side of the plurality of third through holes  7 A with respect to second space S 2 . Distributor  101  is provided therein with a refrigerant path extending upward sequentially through first space S 1 , third space S 3 , second space S 2 , and the plurality of third through holes  7 A to each of the plurality of heat transfer tubes  200 . 
     &lt;Functions and Effects&gt; 
     Since distributor  101  has basically the same configuration as that of distributor  100 , it can achieve the same functions and effects as those of distributor  100  described above. 
     Furthermore, in distributor  101 , the length of second space S 2  in second direction B can be shorter than that in distributor  100 , and can be reduced to the half of the length of second space S 2  in second direction B in distributor  100 , for example. As a result, the volume of the refrigerant path inside distributor  101  can be set at approximately 20% of the volume of the refrigerant path inside the conventional two-phase side horizontal distributor formed of a circular tube extending in the first direction, for example (see  FIGS. 34  (A) and  34  (C)). 
     Distributor  101  according to the second embodiment does not have to include fifth member  5  as long as second space S 2  can be maintained. In this case, seventh member  7  of distributor  101  only has to be fixed to the plurality of heat transfer tubes  200  by an optional method. Even distributor  101  as described above can achieve the same effect as that of distributor  101  described above. 
     Third Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, a distributor  102  according to the third embodiment will be described with reference to  FIGS. 8 and 9 . Distributor  102  according to the third embodiment has basically the same configuration as those of distributors  100  and  101  according to the first and second embodiments, but is different therefrom in the following points. Specifically, the third direction extending from first space S 1  through third space S 3  to second space S 2  extends in second direction B, and the fourth direction extending from second space S 2  to third through hole  7 A is directed from top to bottom. 
     As shown in  FIGS. 8 and 9 , distributor  102  includes a second member  2 , a third member  3 , a fifth member  5 , a seventh member  7 , and a tenth member  10 . Second member  2 , third member  3 , fifth member  5 , seventh member  7 , and tenth member  10  each are formed of a plate-shaped member, for example. When second member  2 , fifth member  5 , seventh member  7 , and tenth member  10  are seen in up-down direction C, the outline shape of each member has a rectangular shape, for example, having a long-side direction extending in first direction A. 
     The cross-sectional shape of tenth member  10  that is perpendicular to first direction A is an L-shape, for example. Tenth member  10  is formed by bending a plate-shaped member, for example. Tenth member  10  includes a first member  1  and a sixth member  6 . The long-side direction of first member  1  in the cross section perpendicular to first direction A extends in up-down direction C. The long-side direction of sixth member  6  in the cross section perpendicular to first direction A extends in second direction B. 
     First member  1  has basically the same configuration as that of first member  1  in each of distributors  100  and  101 , but is different therefrom in the following points. Specifically, first member  1  is provided with the plurality of first through holes  1 A having hole axes extending in second direction B, and is formed integrally with sixth member  6 . The plurality of first through holes  1 A are spaced apart from each other in first direction A. The plurality of first through holes  1 A are provided above sixth member  6 . In the cross section perpendicular to first direction A, the lower ends of the plurality of first through holes  1 A are located on the same straight line as the upper surface of sixth member  6 , for example. The upper surface of sixth member  6  faces a second through hole  3 A of third member  3 , a fifth through hole  5 A of fifth member  5 , and a third through hole  7 A of seventh member  7 , each of which will be described later. 
     Second member  2  has basically the same configuration as that of second member  2  in each of distributors  100  and  101 , but is different therefrom in that the opening end of groove  2 A is directed in second direction B. Groove  2 A faces the plurality of first through holes  1 A. Groove  2 A extends in first direction A. 
     Third member  3  has basically the same configuration as that of third member  3  in each of distributors  100  and  101 , but is different therefrom in that the outline shape of third member  3  has a C-shape when third member  3  is seen in up-down direction C. In a different point of view, second through hole  3 A is opened to one end face of third member  3  in second direction B. Second through hole  3 A has an inner circumferential surface extending in first direction A. This inner circumferential surface is disposed so as to face the plurality of first through holes  1 A in second direction B. 
     Fifth member  5  has basically the same configuration as that of fifth member  5  in each of distributors  100  and  101 . The plurality of fifth through holes  5 A face second through hole  3 A. 
     Seventh member  7  has basically the same configuration as that of seventh member  7  in distributor  101 , but is different therefrom in that caulking portion  71  is disposed to face each other with the bent portion of second member  2  interposed therebetween in up-down direction C. As shown in  FIG. 8 , seventh member  7  serves to caulk tenth member  10 , second member  2 , third member  3 , and fifth member  5 . 
     As shown in  FIG. 8 , a first space S 1  is provided inside groove  2 A. First space S 1  extends in first direction A. A second space S 2  is provided inside second through hole  3 A of third member  3 . A third space S 3  is provided inside each of the plurality of first through holes  1 A. First space S 1  and second space S 2  are connected to each other through third space S 3 . In other words, first member  1  provides a partition between first space S 1  and second space S 2 . Third space S 3  is higher in flow path resistance than first space S 1  and second space S 2 . 
     As shown in  FIG. 8 , in distributor  102 , the third direction from first space S 1  through third space S 3  to second space S 2  extends in second direction B while the fourth direction from second space S 2  to third through hole  7 A is directed downward. 
     Distributor  102  is provided therein with: a refrigerant path extending in second direction B from first space S 1  through third space S 3  to second space S 2 ; and on the downstream side of the refrigerant path, a refrigerant path extending from second space S 2  through the plurality of third through holes  7 A to each of the plurality of heat transfer tubes  200 . 
     &lt;Functions and Effects&gt; 
     Since distributor  102  has the basically the same configuration as that of distributor  100 , it can achieve the same functions and effects as those of distributor  100  described above. 
     Furthermore, distributor  102  can be reduced in length of second space S 2  in second direction B so as to be shorter than that of distributor  100 . Consequently, the volume of the refrigerant path inside distributor  101  can be set to be 40% or less of the volume of the refrigerant path inside the conventional horizontal distributor formed of a circular tube extending in the first direction, for example. 
     Furthermore, in distributor  102 , the circulation direction of the refrigerant can be changed in second space S 2 , as in distributor  100 . Thus, distributor  102  can facilitate spreading of the gas-liquid two-phase refrigerant inside second space S 2 , thereby allowing more uniform distribution of the gas-liquid two-phase refrigerant to each of the plurality of heat transfer tubes  200 . 
     In distributors  100  and  102 , third member  3  may be provided with a second groove in place of second through hole  3 A while second space S 2  may be disposed inside the groove. The second groove only has to have basically the same configuration as that of second through hole  3 A described above. The inner diameter of the second groove in second direction B is longer than the total sum of the inner diameter of first through hole  1 A in second direction B and the inner diameter of fourth through hole  1 B in second direction B. In distributor  100  including third member  3  as describe above, third member  3  is disposed such that the opening end of the second groove is directed upward, thereby allowing elimination of fourth member  4 . Furthermore, in distributor  102  including third member  3  described above, third member  3  is disposed such that the opening end of the second groove is directed upward, thereby allowing elimination of sixth member  6 . In other words, in each of distributors  100  and  102 , the second groove provided in third member  3  may be formed as second through hole  3 A extending to the main surface located on the opposite side of the above-mentioned main surface or may be formed as a groove obtained by providing a bottom portion inside third member  3 . 
     In each of distributors  100 ,  101  and  102 , at least some of first member  1 , second member  2 , third member  3 , fourth member  4 , fifth member  5 , sixth member  6 , and seventh member  7  may be integrated with each other. For example, third member  3  in distributor  100  may be integrated with fourth member  4 . For example, first member  1  in distributor  102  may be integrated with fifth member  5  or third member  3 . 
     Fourth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, referring to  FIGS. 10 and 11 , the distributor according to the fourth embodiment will be hereinafter described. The distributor according to the fourth embodiment has basically the same configuration as that of distributor  100  according to the first embodiment, but is different therefrom in that third member  3  is provided with a plurality of second through holes  3 A (recess portions) that are spaced apart from each other in first direction A. 
     As shown in  FIGS. 10 and 11 , a portion  3 B extending in second direction B is disposed between the plurality of second through holes  3 A. The plurality of second through holes  3 A have the same configuration, for example. One second through hole  3 A faces one first through hole  1 A and one fourth through hole  1 B, for example. One second space S 2  is disposed inside each of the plurality of second through holes  3 A. 
     The planar shape of second through hole  3 A as seen in up-down direction C is a rectangular shape, for example. The inner diameter of second through hole  3 A in first direction A is shorter than the inner diameter of second through hole  3 A in second direction B. The inner diameter of second through hole  3 A in first direction A is longer than the inner diameter of first through hole  1 A in first direction A and than the inner diameter of fourth through hole  1 B in first direction A. The inner diameter of second through hole  3 A in second direction B is longer than the total sum of the inner diameter of first through hole  1 A in second direction B and the inner diameter of fourth through hole  1 B in second direction B. In other words, in the distributor according to the fourth embodiment, third member  3  of distributor  100  is replaced with third member  3  provided with a plurality of second through holes  3 A. 
     &lt;Functions and Effects&gt; 
     Also in this way, the inner diameter of second through hole  3 A in first direction A is longer than the inner diameter of first through hole  1 A in first direction A and than the inner diameter of fourth through hole  1 B in first direction A. Thus, refrigerant can spread in second direction B inside each second space S 2 . As a result, the distributor according to the fourth embodiment can uniformly distribute gas-liquid two-phase refrigerant to each of the plurality of refrigerant paths spaced apart from each other in second direction B inside each heat transfer tube  200  introduced into each of the plurality of third through holes  7 A. 
     Furthermore, the distributor according to the fourth embodiment can be reduced in volume of second space S 2  as compared with distributor  100 . 
     &lt;Modifications&gt; 
     The distributor according to the fourth embodiment has basically the same configuration as that of the distributor in the second or third embodiment, and may be different therefrom in that third member  3  is provided with a plurality of second through holes  3 A (recess portions) that are spaced apart from each other in first direction A. 
     As shown in  FIG. 12 , each of the plurality of second through holes  3 A may face one first through hole  1 A and one fifth through hole  5 A. In other words, the distributor according to the fourth embodiment may be configured such that third member  3  of distributor  101  is replaced with third member  3  provided with a plurality of second through holes  3 A. The inner diameter of second through hole  3 A in first direction A is longer than the inner diameter of first through hole  1 A in first direction A and than the inner diameter of fifth through hole  5 A in first direction A. The inner diameter of second through hole  3 A in second direction B is longer than the inner diameter of first through hole  1 A in second direction B and than the inner diameter of fourth through hole  1 B in second direction B. The distributor according to the fourth embodiment as described above can be reduced in volume of second space S 2  as compared with distributor  101 . 
     As shown in  FIG. 13 , each of the plurality of second through holes  3 A may be opened to one end face of third member  3  in second direction B. In other words, the distributor according to the fourth embodiment may be configured such that third member  3  of distributor  102  is replaced with third member  3  provided with a plurality of second through holes  3 A. The outline shape of third member  3  is a comb shape, for example, in a top view of third member  3  in up-down direction C. Each of the plurality of second through holes  3 A has an inner circumferential surface extending in first direction A. Each of the inner circumferential surfaces is disposed to face each of the plurality of first through holes  1 A in second direction B. The distributor according to the fourth embodiment as described above can be reduced in volume of second space S 2  as compared with distributor  102 . 
     Fifth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the fifth embodiment will be described with reference to  FIGS. 14 and 15 . The distributor according to the fifth embodiment has basically the same configuration as that of distributor  100  according to the first embodiment, but is different therefrom in that a plurality of first through holes  1 A include a first group of first through holes  1 C and a second group of first through holes  1 D disposed such that the first group of first through holes  1 C is spaced apart from the second group of first through holes  1 D in first direction A. In  FIG. 14 , a second through hole  3 A of third member  3  disposed to overlap with first member  1  in up-down direction C is shown by a dotted line. 
     As shown in  FIG. 14 , each of first through holes  1 C in the first group of first through holes  1 C is spaced apart from each of first through holes  1 D in the second group of first through holes  1 D in second direction B. First through holes  1 C in the first group of first through holes  1 C have the same configuration, for example. First through holes  1 D in the second group of first through holes  1 D have the same configuration, for example. The opening area of each of first through holes  1 C in the first group of first through holes  1 C is smaller than the opening area of each of first through holes  1 D in the second group of first through holes  1 D. The opening area of each of first through holes  1 C in the first group of first through holes  1 C is 10% or more and 50% or less of the opening area of each of first through holes  1 D in the second group of first through holes  1 D, for example. The planar shape of each of first through holes  1 C and  1 D as seen in up-down direction C is a circular shape, for example. 
     As shown in  FIG. 14 , each of first through holes  1 C in the first group of first through holes  1 C is spaced apart from each of the plurality of fourth through holes  1 B in the direction crossing: first direction A; and the extending direction of the hole axis of each first through hole  1 C. Each of first through holes  1 C in the first group of first through holes  1 C is spaced apart from each of the plurality of fourth through holes  1 B in second direction B. The first group of first through holes  1 C is provided in first member  1  between the second group of first through holes  1 D and each of the plurality of fourth through holes  1 B, for example. 
     Third space S 3  is provided inside each of: first through holes  1 C in the first group of first through holes  1 C; and first through holes  1 D in the second group of first through holes  1 D. The flow path resistance in third space S 3  inside each of first through holes  1 C in the first group of first through holes  1 C and the flow path resistance in third space S 3  inside each of first through holes  1 D in the second group of first through holes  1 D are higher than the flow path resistance in first space S 1  and the flow path resistance in second space S 2 . The flow path resistance in third space S 3  inside each of first through holes  1 C in the first group of first through holes  1 C is higher than the flow path resistance in third space S 3  inside each of first through holes  1 D in the second group of first through holes  1 D. 
     An inflow portion through which refrigerant is introduced into first space S 1  is connected, for example, to the center portion of groove  2 A of second member  2  in first direction A. As shown in  FIG. 15 , a connection hole  2 C for connecting the inflow portion is formed in the center portion of second member  2  in first direction A. 
     Connection hole  2 C faces first space S 1  inside groove  2 A. In the distributor according to the fifth embodiment, refrigerant flows through first space S 1  from the center portion in first direction A to the outside. Connection hole  2 C is located closer to the second group of first through holes  1 D than to the first group of first through holes  1 C, for example. 
     &lt;Functions and Effects&gt; 
     The gas-liquid two-phase refrigerant flowing from first space S 1  through one of the plurality of first through holes  1 A into second space S 2  flows through first space S 1  in first direction A to thereby undergo pressure loss and also flows through first through hole  1 A to thereby undergo pressure loss. In distributor  100  provided with the plurality of first through holes  1 A having equally small opening areas, pressure loss is more likely to occur in the refrigerant path extending through first through hole  1 A farther away from the inflow portion. The gas-phase refrigerant in the gas-liquid two-phase refrigerant is more likely to flow through a path that is less likely to undergo pressure loss as compared with the liquid-phase refrigerant. Accordingly, the gas-phase refrigerant flowing into first space S 1  extending in first direction A is more likely to flow through the refrigerant path extending through first through hole  1 A close to the inflow portion. On the other hand, the liquid-phase refrigerant flowing into first space S 1  extending in first direction A may flow through first space S 1  to the region located at a distant from the inflow portion. Thus, in distributor  100 , the proportion of the gas-phase refrigerant in the gas-liquid two-phase refrigerant flowing through first through hole  1 A that is relatively distant from the inflow portion in first direction A may be smaller than the proportion of the gas-phase refrigerant in the gas-liquid two-phase refrigerant flowing through first through hole  1 A that is relatively close to the inflow portion in first direction A. 
     In contrast, according to the distributor in the fifth embodiment, the opening area of each of first through holes  1 D in the second group of first through holes  1 D is larger than the opening area of each of first through holes  1 C in the first group of first through holes  1 C. Accordingly, the gas-phase refrigerant in the gas-liquid two-phase refrigerant is more likely to flow through the space, which is closer to the second group of first through holes  1 D than to the first group of first through holes  1 C in first space S 1 , to the region where the inflow portion is at a distant from connection hole  2 C. In other words, according to the distributor in the fifth embodiment, the gas-phase refrigerant can be caused to flow farther away from connection hole  2 C in first space S 1  as compared with distributor  100 . As a result, the amount of the liquid-phase refrigerant emitted from third space S 3  into second space S 2  inside the first group of first through holes  1 C and the amount of the gas-phase refrigerant emitted from third space S 3  into second space S 2  inside the second group of first through holes  1 D can be further equalized in first direction A. Thereby, the gas-liquid two-phase refrigerant mixed in second space S 2  is further equalized in first direction A. Thus, the distributor according to the fifth embodiment can distribute the gas-liquid two-phase refrigerant more equally in first direction A. 
     &lt;Modifications&gt; 
     The distributor according to the fifth embodiment has basically the same configuration as that of one of the distributors according to the second to fourth embodiments, but may be different therefrom in that the plurality of first through holes  1 A include the first group of first through holes  1 C and the second group of first through holes  1 D that are spaced apart from each other in first direction A. First member  1  in the distributor according to the fifth embodiment may have basically the same configuration as that of first member  1  in distributor  102 . In this case, each of first through holes  1 C in the first group of first through holes  1 C is spaced apart from each of first through holes  1 D in the second group of first through holes  1 D in up-down direction C crossing each of first direction A and second direction B that corresponds to the extending direction of the hole axis of each first through hole  1 C. Each of first through holes  1 C in the first group of first through holes  1 C is disposed below each of first through holes  1 D in the second group of first through holes  1 D, for example. 
     Furthermore, as shown in  FIG. 16 , each of the first group of first through holes  1 C and the second group of first through holes  1 D may be disposed to face each of the plurality of second through holes  3 A. In  FIG. 16 , the plurality of second through holes  3 A in third member  3  disposed to overlap with first member  1  in up-down direction C are shown by a dotted line. One first through hole  1 C and one first through hole  1 D may be disposed inside one second through hole  3 A. The distributor according to the fifth embodiment having the configuration as described above can further achieve the same effect as that of the distributor according to the fourth embodiment. 
     Furthermore, the inflow portion through which refrigerant flows into first space S 1  may be connected to one end of groove  2 A of second member  2  in first direction A, for example. Also in this way, according to the distributor in the fifth embodiment, the gas-phase refrigerant in the gas-liquid two-phase refrigerant can be caused to flow to the other end of first space S 1  in first direction A to which the inflow portion is not connected. Thus, the gas-liquid two-phase refrigerant can be more uniformly distributed in first direction A. 
     Sixth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the sixth embodiment will be described with reference to  FIGS. 17 and 18 . The distributor according to the sixth embodiment has basically the same configuration as that of the distributor according to the fifth embodiment, but is different therefrom in that it further includes a plurality of partition members  2 D disposed inside first space S 1  to be spaced apart from each other in first direction A.  FIG. 17  is a cross-sectional view of second member  2  of the distributor according to the sixth embodiment, which is perpendicular to up-down direction C. In  FIG. 17 , a plurality of first through holes  1 A in first member  1  disposed to overlap with second member  2  in up-down direction C are shown by a dotted line. 
     As shown in  FIG. 17 , each of the plurality of partition members  2 D is disposed between first through holes  1 C in the first group of first through holes  1 C as seen from first space S 1 . Each of the plurality of first through holes  1 C faces each space located between the plurality of partition members  2 D in first space S 1 . The plurality of partition members  2 D have the same configuration, for example. The cross-sectional shape of each of the plurality of partition members  2 D that is perpendicular to up-down direction C may be any shape having a long-side direction extending in second direction B and a short-side direction extending in first direction A, and may be a rectangular shape, for example. The plurality of partition members  2 D are formed to be integrated with second member  2 , for example. 
     As shown in  FIG. 18 , partition member  2 D is in contact with the surface of first member  1  that faces groove  2 A, for example. In a different point of view, partition member  2 D has a surface that is continuous to the above-mentioned main surface of second member  2  that faces the plurality of first through holes  1 A. Partition member  2 D has a surface that is located on the opposite side of the surface in contact with first member  1  and that faces the inner surface of groove  2 A, for example. In a different point of view, the above-mentioned space located between the plurality of partition members  2 D in first space S 1  is connected to another space that is not located between the plurality of partition members  2 D in first space S 1  in second direction B and up-down direction C. 
     &lt;Functions and Effects&gt; 
     According to the distributor in the sixth embodiment, liquid-phase refrigerant is more likely to accumulate in the above-mentioned space located between the plurality of partition members  2 D in first space S 1 . The space faces the first group of first through holes  1 C. Accordingly, in the distributor according to the sixth embodiment, the liquid-phase refrigerant is more likely to flow through the first group of first through holes  1 C as compared with the distributor not including partition member  2 D. Furthermore, pressure loss is more likely to occur in the above-mentioned space as compared with another region in first space S 1 . Thus, in the distributor according to the sixth embodiment, the gas-phase refrigerant is more likely to flow through the second group of first through holes  1 D as compared with the distributor not including partition member  2 D. As a result, according to the distributor in the sixth embodiment, the gas-liquid two-phase refrigerant can be distributed more uniformly as compared with the distributor not including partition member  2 D. 
     Seventh Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the seventh embodiment will be described with reference to  FIG. 19 . The distributor according to the seventh embodiment has basically the same configuration as that of distributor  100  according to the first embodiment, but is different therefrom in that at least one end of first space S 1  in first direction A has a semicircular cross-sectional shape perpendicular to up-down direction C. 
     At each of both ends of groove  2 A of second member  2  in first direction A, the cross-sectional shape perpendicular to up-down direction C is a semicircular shape, for example. First space S 1  is provided inside groove  2 A, and therefore, has both ends in first direction A each having a semicircular cross-sectional shape perpendicular to up-down direction C. 
     As shown in  FIG. 19 , a connection hole  2 C to which an inflow portion is to be connected is provided in the center portion of second member  2  in first direction A. Connection hole  2 C faces first space S 1  inside groove  2 A. In this case, refrigerant flows through first space S 1  from the center portion in first direction A to the outside. 
     &lt;Functions and Effects&gt; 
     Due to the surface tension of the liquid-phase refrigerant in the gas-liquid two-phase refrigerant, the liquid-phase refrigerant flows through first space S 1  along the inner surface of groove  2 A. Thus, according to the distributor in the seventh embodiment, the liquid-phase refrigerant is less likely to accumulate at both ends of first space S 1  in first direction A, as compared with the case where the cross-sectional shape of first space S 1  perpendicular to up-down direction C is a rectangular shape. Consequently, the distributor according to the seventh embodiment can distribute the gas-liquid two-phase refrigerant more uniformly in first direction A. 
     &lt;Modifications&gt; 
     The distributor according to the seventh embodiment has basically the same configuration as that of any one of the distributors according to the second to sixth embodiments, but may be different therefrom in that at least one of ends of first space S 1  in first direction A has a semicircular cross-sectional shape perpendicular to up-down direction C. 
     A plurality of first through holes  1 A in the distributor according to the seventh embodiment may include a first group of first through holes  1 C and a second group of first through holes  1 D as in the distributor according to the fifth embodiment. 
     Eighth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the eighth embodiment will be described with reference to  FIG. 20 . The distributor according to the eighth embodiment has basically the same configuration as that of the distributor according to the first embodiment, but is different therefrom in that the opening area of first through hole  1 A among the plurality of first through holes  1 A that is relatively far away from the inflow portion in first direction A is smaller than the opening area of first through hole  1 A among the plurality of first through holes  1 A that is relatively close to the inflow portion.  FIG. 20  is a plan view showing first member  1  according to the eighth embodiment as seen in up-down direction C. In  FIG. 20 , the portion overlapping with inflow portion  8  in up-down direction C is shown by an arrow. 
     The opening areas of the plurality of first through holes  1 A change gradually according to their positions in first direction A, for example. 
     &lt;Functions and Effects&gt; 
     As described above, the gas-liquid two-phase refrigerant flowing from first space S 1  through any one of the plurality of first through holes  1 A into second space S 2  flows through first space S 1  in first direction A to thereby undergo pressure loss, and also flows through first through hole  1 A to thereby undergo pressure loss. In the distributor according to the eighth embodiment, the pressure loss caused due to flowing through first space S 1  in first direction A is greater as first through hole  1 A is located farther away from the inflow portion, whereas the pressure loss caused due to flowing through first through hole  1 A is smaller as first through hole  1 A is located farther away from the inflow portion. Thus, according to the distributor in the eighth embodiment, the pressure loss in each of the plurality of refrigerant paths extending from first space S 1  through any one of the plurality of first through holes  1 A into second space S 2  can be equalized irrespective of the positions of the corresponding first through holes  1 A in first direction A. Accordingly, the gas-phase refrigerant in the gas-liquid two-phase refrigerant can be distributed more uniformly inside the plurality of first through holes  1 A in first direction A. Consequently, according to the distributor in the eighth embodiment, the gas-liquid two-phase refrigerant can be distributed more uniformly in first direction A. 
     &lt;Modifications&gt; 
     The distributor according to the eighth embodiment has basically the same configuration as that of any one of the distributors according to the second to seventh embodiments, but may be different therefrom in that the opening area of first through hole  1 A among the plurality of first through holes  1 A that is located relatively far away from the inflow portion in first direction A is smaller than the opening area of first through hole  1 A among the plurality of first through holes  1 A that is located relatively close to this inflow portion. The distributor according to the eighth embodiment may include a first group of first through holes  1 C and a second group of first through holes  1 D as in the distributor according to the fifth embodiment, for example. In at least one of the first group of first through holes  1 C and the second group of first through holes  1 D, the opening areas of first through holes  1 C and  1 D that are relatively far away from the inflow portion in first direction A are smaller than the opening areas of first through holes  1 C and  1 D, respectively, that are relatively close to this inflow portion. 
     Ninth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the ninth embodiment will be described with reference to  FIGS. 21 to 25 . A distributor  109  according to the ninth embodiment has basically the same configuration as that of the distributor according to the fourth embodiment, but is different therefrom in that it includes a bottom surface  109 B located on the opposite side of upper surface  109 A, and is provided with a drainage channel hole  11  extending from upper surface  109 A to bottom surface  109 B and not connected to each of first space S 1 , second space S 2  and third space S 3 .  FIG. 21  is a cross-sectional view of the portion provided with drainage channel hole  11  in distributor  109 , which is perpendicular to first direction A. 
     As shown in  FIGS. 21 and 22 , upper surface  109 A is a main surface of second member  2  that is located on the opposite side of the main surface facing first member  1 . Second member  2  is provided with: a plurality of third through holes  2 B spaced apart from each other in first direction A; and a plurality of drainage channel holes  2 E each located between the plurality of third through holes  2 B. The plurality of drainage channel holes  2 E are spaced apart from each other in first direction A. The plurality of drainage channel holes  2 E are spaced apart from groove  2 A in second direction B. The inner diameter of each of the plurality of drainage channel holes  2 E in first direction A is shorter than the inner diameter of each of the plurality of third through holes  2 B in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  2 E in second direction B is longer than the inner diameter of each of the plurality of third through holes  2 B in second direction B, for example. 
     As shown in  FIGS. 21 and 23 , first member  1  is provided with: a plurality of fourth through holes  1 B spaced apart from each other in first direction A; and a plurality of drainage channel holes  1 E each located between the plurality of fourth through holes  1 B. In other words, the plurality of drainage channel holes  1 E are disposed not side by side with the plurality of first through holes  1 A in second direction B, and also not connected to third space S 3  inside each of the plurality of first through holes  1 A. The plurality of drainage channel holes  1 E are spaced apart from each other in first direction A. The inner diameter of each of the plurality of drainage channel holes  1 E in first direction A is shorter than the inner diameter of each of the plurality of fourth through holes  1 B in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  1 E in second direction B is longer than the inner diameter of each of the plurality of fourth through holes  1 B in second direction B, for example. 
     As shown in  FIGS. 21 and 24 , third member  3  is provided with: a plurality of second through holes  3 A spaced apart from each other in first direction A; and a plurality of drainage channel holes  3 E each located between the plurality of second through holes  3 A. In other words, the plurality of drainage channel holes  3 E are disposed on a portion  3 B located between the plurality of second through holes  3 A and extending in second direction B, but not connected to second space S 2  inside each of the plurality of second through holes  3 A. The plurality of drainage channel holes  3 E are spaced apart from each other in first direction A. The inner diameter of each of the plurality of drainage channel holes  3 E in first direction A is shorter than the inner diameter of each of the plurality of second through holes  3 A in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  3 E in second direction B is shorter than the inner diameter of each of the plurality of second through holes  3 A in second direction B, for example. 
     As shown in  FIGS. 21 and 25 , bottom surface  109 B is a main surface of fourth member  4  that is located on the opposite side of the main surface facing third member  3 . Fourth member  4  is provided with a plurality of drainage channel holes  4 E spaced apart from each other in first direction A. 
     As shown in  FIGS. 21 to 25 , the plurality of drainage channel holes  2 E in second member  2 , the plurality of drainage channel holes  1 E in first member  1 , the plurality of drainage channel holes  3 E in third member  3 , and the plurality of drainage channel holes  4 E in fourth member  4  are disposed to be overlaid on one another in up-down direction C. The plurality of drainage channel holes  2 E, the plurality of drainage channel holes  1 E, the plurality of drainage channel holes  3 E, and the plurality of drainage channel holes  4 E are identical in planar shape as seen in up-down direction C, for example. The plurality of drainage channel holes  2 E, the plurality of drainage channel holes  1 E, the plurality of drainage channel holes  3 E, and the plurality of drainage channel holes  4 E are connected sequentially from top to bottom to form a plurality of drainage channel holes  11 . 
     &lt;Functions and Effects&gt; 
     Distributor  109  according to the ninth embodiment is provided with a plurality of drainage channel holes  11  extending from upper surface  109 A to bottom surface  109 B between the plurality of third through holes  2 B, into which the lower ends of the plurality of heat transfer tubes  200  are introduced. Thus, according to distributor  109 , liquid such as water having flown through the plurality of heat transfer tubes  200  to upper surface  109 A can be discharged through the plurality of drainage channel holes  11  to bottom surface  109 B of distributor  109 . Accordingly, in distributor  109 , for example, when dew condensation water produced by the defrosting operation on the fins and heat transfer tubes  200  is discharged through each heat transfer tube  200  in the downward direction, accumulation of such dew condensation water on upper surface  109 A is prevented. Consequently, the heat exchanger including distributor  109  can immediately discharge the dew condensation water produced during the defrosting operation in the downward direction. Thus, the heating operation can be performed with high efficiency while corrosion of distributor  109  due to accumulation of dew condensation water is suppressed. 
     In addition, since the plurality of drainage channel holes  11  are not connected to each of first space S 1 , second space S 2  and third space S 3 . Thus, distributor  109  has the same refrigerant distribution performance as that of the distributor according to the fourth embodiment. 
     &lt;Modifications&gt; 
     The distributor according to the ninth embodiment has basically the same configuration as that of any one of the distributors according to the first to third and fifth to eighth embodiments, but may be different therefrom in that it has a bottom surface located on the opposite side of the upper surface and also includes a drainage channel hole extending from the upper surface to the bottom surface and not connected to each of first space S 1 , second space S 2  and third space S 3 . 
     For example, in the distributor according to the ninth embodiment having the same configuration as that of distributor  100  according to the first embodiment, the drainage channel hole only has to be spaced apart from first through hole  1 A, second through hole  3 A, third through hole  2 B and fourth through hole  1 B in at least one of first direction A and second direction B. 
     For example, in the distributor according to the ninth embodiment having the same configuration as that of each of distributors  101  and  102  according to the second and third embodiment, the drainage channel hole only has to be spaced apart from first through hole  1 A, groove  2 A, second through hole  3 A, third through hole  7 A and fifth through hole  5 A in at least one of first direction A and second direction B. 
     The inner circumferential surface of drainage channel hole  11  may be provided with protrusions and recesses. The top portion and the bottom portion in each of the protrusions and recesses extend in up-down direction C. In this way, the dew condensation water having flown into the plurality of drainage channel holes  11  can be more effectively discharged through these protrusions and recesses. 
     In the distributor according to the ninth embodiment, the plurality of drainage channel holes  11  may be spaced apart from each other in second direction B. 
     Tenth Embodiment 
     &lt;Configuration of Distributor&gt; 
     Then, the distributor according to the tenth embodiment will be described with reference to  FIGS. 26 to 30 . A distributor  110  according to the tenth embodiment has basically the same configuration as that of the distributor according to the fourth embodiment, but is different therefrom in that: second member  2  as an outer member further includes a side surface  110 B extending in the direction crossing the above-described upper surface  110 A; and a drainage channel hole  12  is provided that extends from upper surface  110 A to side surface  110 B and not connected to each of first space S 1 , second space S 2  and third space S 3 .  FIG. 26  is a cross-sectional view of a portion of distributor  110  that is provided with drainage channel hole  12 , which is perpendicular to first direction A. 
     As shown in  FIGS. 26 and 27 , upper surface  110 A is a main surface of second member  2  that is located on the opposite side of the main surface facing first member  1 . Second member  2  is provided with: a plurality of third through holes  2 B spaced apart from each other in first direction A; and a plurality of drainage channel holes  2 E each disposed between the plurality of third through holes  2 B. The plurality of drainage channel holes  2 E are spaced apart from each other in first direction A. The plurality of drainage channel holes  2 E are spaced apart from groove  2 A in second direction B. The inner diameter of each of the plurality of drainage channel holes  2 E in first direction A is shorter than the inner diameter of each of the plurality of third through holes  2 B in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  2 E in second direction B is longer than the inner diameter of each of the plurality of third through holes  2 B in second direction B, for example. 
     As shown in  FIGS. 26 and 28 , first member  1  is provided with: a plurality of fourth through holes  1 B spaced apart from each other in first direction A; and a plurality of drainage channel holes  1 E each located between the plurality of fourth through holes  1 B. In other words, the plurality of drainage channel holes  1 E are arranged not side by side with the plurality of first through holes  1 A in second direction B and also not connected to third space S 3  inside each of the plurality of first through holes  1 A. The plurality of drainage channel holes  1 E are spaced apart from each other in first direction A. The inner diameter of each of the plurality of drainage channel holes  1 E in first direction A is shorter than the inner diameter of each of the plurality of fourth through holes  1 B in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  1 E in second direction B is shorter than the inner diameter of each of the plurality of fourth through holes  1 B in second direction B, for example. 
     As shown in  FIGS. 26 and 29 , third member  3  is provided with: a plurality of second through holes  3 A spaced apart from each other in first direction A; and a plurality of drainage channel holes  3 E spaced apart from each other in first direction A. A part of each of the plurality of drainage channel holes  3 E is disposed between the plurality of second through holes  3 A. The plurality of drainage channel holes  3 E are not connected to second space S 2  inside each of the plurality of second through holes  3 A. The inner diameter of each of the plurality of drainage channel holes  3 E in first direction A is shorter than the inner diameter of each of the plurality of second through holes  3 A in first direction A, for example. The inner diameter of each of the plurality of drainage channel holes  3 E in second direction B is shorter than the inner diameter of each of the plurality of second through holes  3 A in second direction B, for example. Each of the plurality of drainage channel holes  3 E is opened to one end face of third member  3  in second direction B, for example. 
     As shown in  FIGS. 26 and 30 , fourth member  4  is provided with a plurality of drainage channel holes  4 E spaced apart from each other in first direction A. Each of the plurality of drainage channel holes  4 E is opened to one end face of fourth member  4  in second direction B, for example. Side surface  110 B of distributor  110  is a surface of second member  2  that extends in up-down direction C. Side surface  110 B of second member  2  is provided with a plurality of drainage channel holes  2 F (see  FIG. 26 ) spaced apart from each other in first direction A. 
     As shown in  FIGS. 26 to 30 , each of the plurality of drainage channel holes  2 E in second member  2 , each of the plurality of drainage channel holes  1 E in first member  1 , each of the plurality of drainage channel holes  3 E in third member  3 , each of the plurality of drainage channel holes  4 E in fourth member  4 , and each of the plurality of drainage channel holes  2 F in second member  2  are connected sequentially from top to bottom to form each of the plurality of drainage channel holes  12 . Each of the plurality of drainage channel holes  2 E, each of the plurality of drainage channel holes  1 E, each of the plurality of drainage channel holes  3 E, each of the plurality of drainage channel holes  4 E, and each of the plurality of drainage channel holes  2 F are disposed to be overlaid on one another in the direction inclined to up-down direction C. The extending direction of each of the plurality of drainage channel holes  12  is inclined to up-down direction C. 
     &lt;Functions and Effects&gt; 
     Distributor  110  according to the tenth embodiment is provided with a plurality of drainage channel holes  12  extending from upper surface  110 A to side surface  110 B between the plurality of third through holes  2 B, into which the lower ends of the plurality of heat transfer tubes  200  are introduced. Thus, according to distributor  110 , liquid such as water having flown through the plurality of heat transfer tubes  200  to upper surface  110 A can be discharged through the plurality of drainage channel holes  12  to side surface  110 B of distributor  110 . Accordingly, in distributor  110 , for example, when dew condensation water produced by the defrosting operation on the fins and heat transfer tubes  200  is discharged through each heat transfer tube  200  in the downward direction, accumulation of such dew condensation water on upper surface  110 A is prevented. Consequently, the heat exchanger including distributor  110  can immediately discharge the dew condensation water produced during the defrosting operation in the downward direction. Thus, the heating operation can be performed with high efficiency while corrosion of distributor  110  due to accumulation of dew condensation water is suppressed. 
     Since the plurality of drainage channel holes  12  are not connected to each of first space S 1 , second space S 2  and third space S 3 , distributor  110  has the same refrigerant distribution performance as that of the distributor according to the fourth embodiment. 
     &lt;Modifications&gt; 
     The distributor according to the tenth embodiment has basically the same configuration as that of any one of the distributors according to the first to third and fifth to eighth embodiments, but may be different therefrom in that drainage channel hole  12  is provided that extends from upper surface  110 A to side surface  110 B and is not connected to each of first space S 1 , second space S 2  and third space S 3 . 
     For example, in the distributor according to the tenth embodiment having the same configuration as that of distributor  100  according to the first embodiment, drainage channel hole  12  only has to be spaced apart from first through hole  1 A, second through hole  3 A, third through hole  2 B and fourth through hole  1 B in at least one of first direction A and second direction B. 
     For example, in the distributor according to the tenth embodiment having the same configuration as those of distributors  101  and  102  according to the second and third embodiments, drainage channel hole  12  only has to be spaced apart from first through hole  1 A, groove  2 A, second through hole  3 A, third through hole  7 A, and fifth through hole  5 A in at least one of first direction A and second direction B. 
     The inner circumferential surface of drainage channel hole  12  may be provided with protrusions and recesses. The top portions and the bottom portions in each of the protrusions and recesses extend in up-down direction C. In this way, the dew condensation water having flown into the plurality of drainage channel holes  12  can be more effectively discharged through these protrusions and recesses. 
     In the distributor according to the tenth embodiment, a plurality of drainage channel holes  12  may be provided to be spaced apart from each other in second direction B. As shown in  FIG. 31 , the distributor according to the tenth embodiment may be provided with: a drainage channel hole  12  extending from upper surface  110 A to one side surface  110 B and not connected to each of first space S 1 , second space S 2  and third space S 3 ; and a drainage channel hole  12  extending from upper surface  110 A to the other side surface  110 B and not connected to each of first space S 1 , second space S 2  and third space S 3 . 
     In addition, the heat transfer tube of the heat exchanger according to each of the first to tenth embodiments is not limited to a flat tube but may be a circular tube. In this case, in the distributor according to each of first to tenth embodiments, the planar shape of each of third through holes  2 B and  7 A as seen in up-down direction C may be a circular shape. 
     Although the embodiments of the present invention have been described as above, the above-described embodiments may be variously modified. Furthermore, the scope of the present invention is not limited to above-described embodiments. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims.