Patent Publication Number: US-11391517-B2

Title: Distributor, layered header, heat exchanger, and air-conditioning apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. application Ser. No. 15/748,223 filed on Jan. 29, 2018, which is a U.S. national stage application of International Application No. PCT/JP2015/075350, filed on Sep. 7, 2015, the contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a distributor used for a heating circuit or other circuits, a layered header, a heat exchanger, and an air-conditioning apparatus. 
     BACKGROUND 
     A heat exchanger is configured of a flow path (path) in which a plurality of heat transfer tubes are arranged in parallel, to mitigate a pressure loss of refrigerant flowing in the heat transfer tubes. Each heat transfer tube is provided with, for example, a header or a distributor that is a distribution device for equally distributing refrigerant to respective heat transfer tubes, at a refrigerant entering part thereof. 
     It is important to uniformly distribute refrigerant to the heat transfer tubes for securing the heat transfer property of the heat exchanger. 
     The distribution device is configured such that a plurality of plate bodies are layered to form a distribution flow path for dividing one inlet flow path into a plurality of outlet flow paths to thereby distributively supply refrigerant to the respective heat transfer tubes of the heat exchanger (for example, see Patent Literature 1). 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Application Publication No. 9-189463 
     In such a distribution device, when refrigerant or the like containing liquid flows into the distribution flow path having a bent portion, the liquid flows in a biased manner in the outer peripheral direction of the distribution flow path by the centrifugal force. In that case, at a branch portion provided downstream of the flow path, a large portion of the liquid flows into a particular flow path. This causes a problem that the distribution ratio of the refrigerant is not uniform at the outlet of the distribution flow path. 
     SUMMARY 
     The present invention has been made in view of the aforementioned problem. An object of the present invention is to provide a distributor, a layered header, a heat exchanger, and an air-conditioning apparatus, capable of uniformly supplying refrigerant at an outlet of a distribution flow path. 
     A distributor according to one embodiment of the present invention includes a first flow path; a plurality of second flow paths; and a first branch flow path for dividing the first flow path into the plurality of second flow paths, the first branch flow path including a first communication flow path communicating with the first flow path; a second communication flow path communicating with each of the second flow paths; and a bent portion connecting the first communication flow path and the second communication flow path, the bent portion including an inner peripheral wall portion including an inner face having a first radius of curvature, and an outer peripheral wall portion including an inner face having a second radius of curvature larger than the first radius of curvature, the second communication flow path including an inner wall portion extending from the inner peripheral wall portion of the bent portion, and an outer wall portion extending from the outer peripheral wall portion of the bent portion, the outer wall portion having a liquid film separation unit. 
     The distributor according to one embodiment of the present invention is configured such that a bent portion is provided in a flow path, and even when a liquid component of refrigerant flows in a biased manner on the outer peripheral side of the bent portion by the centrifugal force, the bias of the liquid can be corrected by the liquid film separation unit. Accordingly, it is possible to uniformly distribute the liquid to a plurality of flow paths. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a heat exchanger  1  according to Embodiment 1. 
         FIG. 2  illustrates connection between a heat exchanger unit  2  and a confluence unit  3  of the heat exchanger  1  according to Embodiment 1. 
         FIG. 3  illustrates connection between the heat exchanger unit  2  and the confluence unit  3  of the heat exchanger  1  according to Embodiment 1. 
         FIG. 4  illustrates connection between the heat exchanger unit  2  and the confluence unit  3  of a modification of the heat exchanger  1  according to Embodiment 1. 
         FIG. 5  is a diagram illustrating a configuration of an air-conditioning apparatus  91  to which the heat exchanger  1  according to Embodiment 1 is applied. 
         FIG. 6  is a diagram illustrating a configuration of an air-conditioning apparatus  91  to which the heat exchanger  1  according to Embodiment 1 is applied. 
         FIG. 7  is an exploded perspective view of a layered header  51  according to Embodiment 1. 
         FIG. 8  is a partial enlarged view of a first branch flow path  11  in the layered header  51  according to Embodiment 1. 
         FIG. 9  is an enlarged view of the first branch flow path  11  according to Embodiment 1. 
         FIG. 10  illustrates a flow of liquid refrigerant in a branch flow path in a conventional layered header. 
         FIG. 11  illustrates a flow of liquid refrigerant in the first branch flow path  11  of the layered header  51  according to Embodiment 1. 
         FIG. 12  is an enlarged view of a first branch flow path  11  according to Embodiment 2. 
         FIG. 13  is an enlarged view of a first branch flow path  11  according to Embodiment 3. 
         FIG. 14  is an enlarged view of a first branch flow path  11  according to Embodiment 4. 
         FIG. 15  is an enlarged view of a first branch flow path  11  according to Embodiment 5. 
         FIG. 16  is an enlarged view of a first branch flow path  11  according to Embodiment 6. 
         FIG. 17  is an exploded perspective view of a layered header  251  according to Embodiment 7. 
         FIG. 18  is a partial enlarged view of a first branch flow path  211  in the layered header  251  according to Embodiment 7. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a distributor, a layered header, a heat exchanger, and an air-conditioning apparatus of the present invention will be described with reference to the drawings. 
     It should be noted that configurations, operations, and other features described below are provided for illustrative purposes, and a distributor, a layered header, a heat exchanger, and an air-conditioning apparatus of the present invention are not limited to such configurations, operations, and other features. Further, in the drawings, same or similar parts may be denoted by the same reference numerals, or not denoted by a reference numeral. Further, fine structures are simply illustrated or not illustrated as appropriate. Further, overlapping or similar description may be simplified or omitted as appropriate. 
     Further, while description is given on the case where a distributor, a layered header, or a heat exchanger of the present invention is applied to an air-conditioning apparatus, the present invention is not limited to such a case. For example, the present invention may be applicable to another refrigeration cycle device having a refrigerant cycle circuit. Further, while description is given on the case where a distributor, a layered header, and a heat exchanger of the present invention are of an outdoor heat exchanger of an air-conditioning apparatus, the present invention is not limited to such a case. An indoor heat exchanger of an air-conditioning apparatus is also applicable. Further, while description is made on the case where an air-conditioning apparatus performs switching between heating operation and cooling operation, the present invention is not limited to such a case. The present invention may perform either heating operation or cooling operation. 
     Embodiment 1 
     A distributor, a layered header, a heat exchanger, and an air-conditioning apparatus, according to Embodiment 1, will be described. 
     &lt;Configuration of Heat Exchanger  1 &gt; 
     Hereinafter, a schematic configuration of the heat exchanger  1  according to Embodiment 1 will be described. 
       FIG. 1  is a perspective view of the heat exchanger  1  according to Embodiment 1. 
       FIGS. 2 and 3  illustrate connection between a heat exchanger unit  2  and a confluence unit  3  of the heat exchanger  1  according to Embodiment 1. It should be noted that  FIG. 3  is a cross-sectional view taken along a line A-A of  FIG. 2 . 
     As illustrated in  FIG. 1 , the heat exchanger  1  includes the heat exchanger unit  2  and the confluence unit  3 . 
     (Heat Exchanger Unit  2 ) 
     The heat exchanger unit  2  includes an air-upstream side heat exchanger unit  21  provided on the air-upstream side of the passing direction (void arrow in the drawing) of the air passing through the heat exchanger unit  2 , and a air-downstream side heat exchanger unit  31  provided on the air-downstream side thereof. The air-upstream side heat exchanger unit  21  includes a plurality of air-upstream side heat transfer tubes  22 , and a plurality of air-upstream side fins  23  joined to the air-upstream side heat transfer tubes  22  by brazing, for example. The air-downstream side heat exchanger unit  31  includes a plurality of air-downstream side heat transfer tubes  32 , and a plurality of air-downstream side fins  33  joined to the air-downstream side heat transfer tubes  32  by brazing, for example. It should be noted that while the heat exchanger unit  2  configured of two rows, namely the air-upstream side heat exchanger unit  21  and the air-downstream side heat exchanger unit  31 , is shown as an example, it may be configured of three or more rows. 
     Each of the air-upstream side heat transfer tube  22  and the air-downstream side heat transfer tube  32  is a flat tube, for example, and has a plurality of flow paths therein. Each of the air-upstream side heat transfer tubes  22  and the air-downstream side heat transfer tubes  32  is configured such that a substantially intermediate portion between one end  22   b  and the other end  22   c  is bent in a hairpin shape to form a folded portion  22   a ,  32   a  to be in a substantially U shape. The air-upstream side heat transfer tubes  22  and the air-downstream side heat transfer tubes  32  are disposed in a plurality of stages in a direction orthogonal to the passing direction (void arrow in the drawing) of the air passing through the heat exchanger unit  2 . It should be noted that each of the air-upstream side heat transfer tube  22  and the air-downstream side heat transfer tube  32  may be a circular tube (circular tube with a diameter of 4 mm, for example). 
     While description has been given on the example in which the air-upstream side heat transfer tube  22  and the air-downstream side heat transfer tube  32  are bent in a U shape and the folded portions  22   a  and  32   a  are integrally formed, it is also possible to form the folded portions  22   a  and  32   a  as different members. In that case, a U tube having a flow path therein may be connected to form a folded flow path. 
     (Confluence Unit  3 ) 
     The confluence unit  3  includes a layered header  51  and a cylindrical header  61 . The layered header  51  and the cylindrical header  61  are arranged in parallel along the passing direction (void arrow in the drawing) of the air passing through the heat exchanger unit  2 . To the layered header  51 , a refrigerant pipe (not illustrated) is connected via a connection pipe  52 . To the cylindrical header  61 , a refrigerant pipe (not illustrated) is connected via a connection pipe  62 . Each of the connection pipe  52  and the connection pipe  62  is a circular pipe, for example. 
     Inside the layered header  51  functioning as a distributor, a confluence flow path  51   a  connected to the air-upstream side heat exchanger unit  21  is formed. The confluence flow path  51   a  serves as a distribution flow path that allows refrigerant flowing from a refrigerant pipe (not illustrated) to distributively flow out to a plurality of air-upstream side heat transfer tubes  22  of the air-upstream side heat exchanger unit  21 , when the heat exchanger unit  2  acts as an evaporator. Further, when the heat exchanger unit  2  acts as a condenser, the confluence flow path  51   a  serves as a confluence flow path that merges refrigerant flowing from the air-upstream side heat transfer tubes  22  of the air-upstream side heat exchanger unit  21  and allows the refrigerant to flow to a refrigerant pipe (not illustrated). 
     Inside the cylindrical header  61 , a confluence flow path  61   a  connected to the air-downstream side heat exchanger unit  31  is formed. The confluence flow path  61   a  serves as a distribution flow path that allows refrigerant flowing from a refrigerant pipe (not illustrated) to distributively flow to the air-downstream side heat transfer tubes  32  of the air-downstream side heat exchanger unit  31 , when the heat exchanger unit  2  acts as a condenser. Further, when the heat exchanger unit  2  acts as an evaporator, the confluence flow path  61   a  serves as a confluence flow path that merges refrigerant flowing from the air-downstream side heat transfer tubes  32  of the air-downstream side heat exchanger unit  31  and allows the refrigerant to flow to a refrigerant pipe (not illustrated). 
     This means that when the heat exchanger unit  2  acts as an evaporator, the heat exchanger  1  has the layered header  51  in which a distribution flow path (confluence flow path  51   a ) is formed, and the cylindrical header  61  in which a confluence flow path (confluence flow path  61   a ) is formed, separately. 
     Further, when the heat exchanger unit  2  acts as a condenser, the heat exchanger  1  has the cylindrical header  61  in which a distribution flow path (confluence flow path  61   a ) is formed, and the layered header  51  in which a confluence flow path (confluence flow path  51   a ) is formed, separately. 
     &lt;Connection Between Heat Exchanger Unit  2  and Confluence Unit  3 &gt; 
     Hereinafter, connection between the heat exchanger unit  2  and the confluence unit  3  of the heat exchanger  1  according to Embodiment 1 will be described. 
     As illustrated in  FIGS. 2 and 3 , a air-upstream side joint member  41  is joined to both one end  22   b  and the other end  22   c  of the substantially U-shaped air-upstream side heat transfer tube  22 . The air-upstream side joint member  41  has a flow path formed therein. One end of the flow path has a shape extending along the outer peripheral face of the air-upstream side heat transfer tube  22 , and the other end thereof is in a circular shape. Further, a air-downstream side joint member  42  is joined to both one end  32   b  and the other end  32   c  of the air-downstream side heat transfer tube  32  that is also formed in a substantially U shape. The air-downstream side joint member  42  has a flow path formed therein. One end of the flow path has a shape extending along the outer peripheral face of the air-downstream side heat transfer tube  32 , and the other end thereof is in a circular shape. 
     The air-upstream side joint member  41  joined to the other end  22   c  of the air-upstream side heat transfer tube  22  and the air-downstream side joint member  42  joined to the one end  32   b  of the air-downstream side heat transfer tube  32  are connected by a row connecting pipe  43 . The row connecting pipe  43  is a circular pipe bent in an arcuate shape, for example. To the air-upstream side joint member  41  joined to the one end  22   b  of the air-upstream side heat transfer tube  22 , a connection pipe  57  of the layered header  51  is connected. To the air-downstream side joint member  42  joined to the other end  32   c  of the air-downstream side heat transfer tube  32 , a connection pipe  64  of the cylindrical header  61  is connected. 
     It should be noted that the air-upstream side joint member  41  and the connection pipe  57  may be integrated. Further, the air-downstream side joint member  42  and the connection pipe  64  may be integrated. Furthermore, the air-upstream side joint member  41 , the air-downstream side joint member  42 , and the row connecting pipe  43  may be integrated. 
       FIG. 4  illustrates connection between the heat exchanger unit  2  and the confluence unit  3  of a modification of the heat exchanger  1  according to Embodiment 1. 
     It should be noted that  FIG. 4  is a cross-sectional view taken along a line A-A of  FIG. 2 . 
     As illustrated in  FIG. 3 , the air-upstream side heat transfer tube  22  and the air-downstream side heat transfer tube  32  may be disposed such that the one end  22   b  and the other end  22   c  of the air-upstream side heat transfer tube  22  and the one end  32   b  and the other end  32   c  of the air-downstream side heat transfer tube  32  are arranged in zigzag in a side view of the heat exchanger  1 , or in a checkerboard pattern as illustrated in  FIG. 4 . 
     &lt;Configuration of Air-Conditioning Apparatus  91  to which Heat Exchanger  1  is Applied&gt; 
     Hereinafter, a configuration of an air-conditioning apparatus  91 , to which the heat exchanger  1  according to Embodiment 1 is applied, will be described. 
       FIGS. 5 and 6  are diagrams illustrating a configuration of the air-conditioning apparatus  91  to which the heat exchanger  1  according to Embodiment 1 is applied. It should be noted that  FIG. 5  illustrates the case where heating operation is performed in the air-conditioning apparatus  91 . Further,  FIG. 6  illustrates the case where cooling operation is performed in the air-conditioning apparatus  91 . 
     As illustrated in  FIGS. 5 and 6 , the air-conditioning apparatus  91  includes a compressor  92 , a four-way valve  93 , an outdoor heat exchanger (heat source side heat exchanger)  94 , an expansion device  95 , an indoor heat exchanger (load side heat exchanger)  96 , an outdoor fan (heat source side fan)  97 , an indoor fan (load side fan)  98 , and a controller  99 . The compressor  92 , the four-way valve  93 , the outdoor heat exchanger  94 , the expansion device  95 , and the indoor heat exchanger  96  are connected with each other by refrigerant pipes to form a refrigerant cycle circuit. The four-way valve  93  may be another flow switching device. 
     The outdoor heat exchanger  94  is the heat exchanger  1 . The heat exchanger  1  is provided such that the layered header  51  is positioned on the air-upstream side of the air flow generated when the outdoor fan  97  is driven, and that the cylindrical header  61  is positioned on the air-downstream side. The outdoor fan  97  may be provided on the air-upstream side of the heat exchanger  1  or on the air-downstream side of the heat exchanger  1 . 
     The controller  99  is connected with the compressor  92 , the four-way valve  93 , the expansion device  95 , the outdoor fan  97 , the indoor fan  98 , various sensors, and other devices, for example. When the flow path of the four-way valve  93  is switched by the controller  99 , heating operation and cooling operation are switched from each other. 
     &lt;Operation of Heat Exchanger  1  and Air-Conditioning Apparatus  91 &gt; 
     Hereinafter, operation of the heat exchanger  1  according to Embodiment 1 and the air-conditioning apparatus  91  to which the heat exchanger  1  is applied will be described. 
     (Operation of Heat Exchanger  1  and Air-Conditioning Apparatus  91  at the Time of Heating Operation) 
     Hereinafter, a flow of refrigerant at the time of heating operation will be described with use of  FIG. 5 . 
     High-pressure and high-temperature gas refrigerant, discharged from the compressor  92 , flows into the indoor heat exchanger  96  via the four-way valve  93 , and is condensed through heat exchange with the air supplied by the indoor fan  98  to thereby heat the room. The condensed refrigerant becomes a high-pressure subcooled liquid state, flows out of the indoor heat exchanger  96 , and becomes refrigerant in a low-pressure two-phase gas-liquid state by the expansion device  95 . The low-pressure two-phase gas-liquid refrigerant flows into the outdoor heat exchanger  94 , exchanges heat with the air supplied by the outdoor fan  97 , and is evaporated. The evaporated refrigerant becomes a low-pressure superheated gas state, flows out of the outdoor heat exchanger  94 , and sucked by the compressor  92  via the four-way valve  93 . This means that the outdoor heat exchanger  94  acts as an evaporator at the time of heating operation. 
     In the outdoor heat exchanger  94 , the refrigerant flows into the confluence flow path  51   a  of the layered header  51  and is distributed, and flows into the one end  22   b  of the air-upstream side heat transfer tube  22  of the air-upstream side heat exchanger unit  21 . The refrigerant flowing into the one end  22   b  of the air-upstream side heat transfer tube  22  passes through the folded portion  22   a , flows to the other end  22   c  of the air-upstream side heat transfer tube  22 , and flows into the one end  32   b  of the air-downstream side heat transfer tube  32  of the air-downstream side heat exchanger unit  31  via the row connecting pipe  43 . The refrigerant flowing into the one end  32   b  of the air-downstream side heat transfer tube  32  passes through the folded portion  32   a , flows to the other end  32   c  of the air-downstream side heat transfer tube  32 , and flows into the confluence flow path  61   a  of the cylindrical header  61  and is merged. 
     (Operation of Heat Exchanger  1  and Air-Conditioning Apparatus  91  at the Time of Cooling Operation) 
     Hereinafter, a flow of refrigerant at the time of cooling operation will be described with use of  FIG. 6 . 
     High-pressure and high-temperature gas refrigerant, discharged from the compressor  92 , flows into the outdoor heat exchanger  94  via the four-way valve  93 , exchanges heat with the air supplied by the outdoor fan  97 , and is condensed. The condensed refrigerant becomes a high-pressure subcooled liquid state (or low-quality two-phase gas-liquid state), flows out of the outdoor heat exchanger  94 , and becomes a low-pressure two-phase gas-liquid state by the expansion device  95 . The low-pressure refrigerant in a two-phase gas-liquid state flows into the indoor heat exchanger  96 , exchanges heat with the air supplied by the indoor fan  98  and is evaporated to thereby cool the room. The evaporated refrigerant becomes a low-pressure superheated gas state, flows out of the indoor heat exchanger  96 , and is sucked by the compressor  92  via the four-way valve  93 . This means that the outdoor heat exchanger  94  acts as a condenser at the time of cooling operation. 
     In the outdoor heat exchanger  94 , the refrigerant flows into the confluence flow path  61   a  of the cylindrical header  61  and is distributed, and flows into the other end  32   c  of the air-downstream side heat transfer tube  32  of the air-downstream side heat exchanger unit  31 . The refrigerant flowing into the other end  32   c  of the air-downstream side heat transfer tube  32  passes through the folded portion  32   a  and flows to the one end  32   b  of the air-downstream side heat transfer tube  32 , and flows into the other end  22   c  of the air-upstream side heat transfer tube  22  of the air-upstream side heat exchanger unit  21  via the row connecting pipe  43 . The refrigerant flowing into the other end  22   c  of the air-upstream side heat transfer tube  22  passes through the folded portion  22   a  and flows to the one end  22   b  of the air-upstream side heat transfer tube  22 , and flows into the confluence flow path  51   a  of the layered header  51  and is merged. 
     &lt;Configuration of Layered Header  51 &gt; 
     Hereinafter, a configuration of the layered header  51  of the heat exchanger  1  according to Embodiment 1 will be described. 
       FIG. 7  is an exploded perspective view of the layered header  51  according to Embodiment 1. 
       FIG. 8  is a partial enlarged view of the first branch flow path  11  in the layered header  51  according to Embodiment 1. 
     The layered header  51  (distributor) illustrated in  FIG. 7  is configured of, for example, rectangular first plate bodies  111 ,  112 ,  113 , and  114 , and second plate bodies  121 ,  122 , and  123  interposed between the respective first plate bodies. The first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 , and  123  have the same external shape in a planer view. 
     To the first plate bodies  111 ,  112 ,  113 , and  114  before braze joining, a brazing material is not clad (applied), while on both faces or an either face of the second plate bodies  121 ,  122 , and  123 , a brazing material is clad (applied). From this state, the first plate bodies  111 ,  112 ,  113 , and  114  are layered via the second plate bodies  121 ,  122 , and  123 , and are heated and brazed in a furnace. The first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 ,  123  each are made of, for example, aluminum having a thickness of about 1 to 10 mm. 
     In the layered header  51 , the confluence flow path  51   a  is configured of flow paths formed by the first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 , and  123 . The confluence flow path  51   a  includes a first flow path  10 A, a second flow path  10 B, and a third flow path  10 C that are circular through holes, and the first branch flow path  11  and a second branch flow path  15  that are substantially S-shaped or substantially Z-shaped through grooves. 
     It should be noted that each of the plate bodies is processed by pressing or cutting. When it is processed by pressing, a plate material having a thickness of 5 mm or less capable of being processed by pressing is used. When it is processed by cutting, a plate material having a thickness of 5 mm or more may be used. 
     A refrigerant pipe of a refrigeration cycle device is connected to the first flow path  10 A of the first plate body  111 . The first flow path  10 A of the first plate body  111  communicates with the connection pipe  52  of  FIG. 1 . 
     At almost the center of the first plate body  111  and the second plate body  121 , the circular first flow path  10 A is opened. Further, in the second plate body  122 , a pair of second flow paths  10 B is opened in a circular shape similarly at positions symmetrical with each other with respect to the first flow path  10 A. 
     Furthermore, in the first plate body  114  and the second plate body  123 , the third flow paths  10 C are opened in a circular shape at four positions symmetrical with each other with respect to the second flow path  10 B. The third flow path  10 C of the first plate body  114  communicates with the air-upstream side heat transfer tube  22  of  FIG. 1 . 
     The first flow path  10 A, the second flow path  10 B, and the third flow path  10 C are positioned and opened to communicate with each other when the first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 , and  123  are layered. 
     Further, the first plate body  112  has the first branch flow path  11  that is a substantially S-shaped or substantially Z-shaped through groove, and the first plate body  113  has the second branch flow path  15  that is also a substantially S-shaped or substantially Z-shaped through groove. 
     Here, when the respective plate bodies are layered to form the confluence flow path  51   a , the first flow path  10 A is connected to the center of the first branch flow path  11  formed in the first plate body  112 , and the second flow path  10 B is connected to both ends of the first branch flow path  11 . 
     Further, the second flow path  10 B is connected to the center of the second branch flow path  15  formed in the first plate body  113 , and the third flow path  10 C is connected to both ends of the second branch flow path  15 . 
     In this way, by layering and brazing the first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 , and  123 , the respective flow paths can be connected to form the confluence flow path  51   a.    
     Further, each of the first plate bodies  111 ,  112 ,  113 , and  114  and the second plate bodies  121 ,  122 , and  123  has a positioning unit  30  for fixing the position when each plate member is layered. 
     Specifically, the positioning unit  30  is formed as a through hole, and positioning can be performed by inserting a pin into the through hole. It is also possible to have a configuration in which a recess is formed on one of plate members opposite to each other and a protrusion is formed on the other one, and the recess and the protrusion are fitted to each other when the two plate materials are layered. 
     (First Branch Flow Path  11 ) 
     Next, the structure of the first branch flow path  11  will be described in detail with use of  FIG. 8 . 
     As described above, the first branch flow path  11  is a substantially S-shaped or substantially Z-shaped through groove formed in the first plate body  112 . The first branch flow path  11  is formed of a first communication flow path  12  extending in the short direction (X direction in  FIG. 7 ) of the first plate body  112  and opened, and two second communication flow paths  13  extending from both ends of the first communication flow path  12  in the longitudinal direction (Y direction in  FIG. 7 ) of the first plate body  112  and opened. The first communication flow path  12  and the second communication flow path  13  are connected smoothly by a bent portion  14 . The second communication flow path  13  is configured of a base portion  13 A connected to the bent portion  14 , and a tip portion  13 B extending from the base portion  13 A in the longitudinal direction (Y direction in  FIG. 7 ) of the first plate body  112 . 
     The bent portion  14  is configured such that an inner peripheral wall portion  14 - 1  forming a side wall of the inner peripheral side and an outer peripheral wall portion  14 - 2  forming a side wall of the outer peripheral side are provided to face each other. The inner peripheral wall portion  14 - 1  and the outer peripheral wall portion  14 - 2  are configured as concentric circles, for example. It is configured that the radius of curvature of the inner peripheral wall portion  14 - 1  is smaller than the radius of curvature of the outer peripheral wall portion  14 - 2 . The base portion  13 A of the second communication flow path  13  is configured such that a base inner wall portion  13 A- 1  smoothly extending from the inner peripheral wall portion  14 - 1  of the bent portion  14  and a base outer wall portion  13 A- 2  smoothly extending from the outer peripheral wall portion  14 - 2  of the bent portion  14  are provided to face each other. Further, the tip portion  13 B of the second communication flow path  13  is configured such that a tip inner wall portion  13 B- 1  connected on a straight line to the base inner wall portion  13 A- 1  of the base portion  13 A, and a tip outer wall portion  13 B- 2  connected to the base outer wall portion  13 A- 2  of the base portion  13 A, via a liquid film separation unit  70 , are provided to face each other. In the first communication flow path  12 , the bent portion  14 , and the base portion  13 A of the second communication flow path  13 , a distance between side walls (the inner peripheral wall portion  14 - 1  and the outer peripheral wall portion  14 - 2 , the base inner wall portion  13 A- 1  and the base outer wall portion  13 A- 2 ) facing each other has the same dimension L 1 . A distance (dimension L 2 ) between side walls (the tip inner wall portion  13 B- 1  and the tip outer wall portion  13 B- 2 ) facing each other of the tip portion  13 B is smaller than the dimension L 1 . 
     (Second Branch Flow Path  15 ) 
     Next, the structure of the second branch flow path  15  will be described. 
     As described above, the second branch flow path  15  is a substantially S-shaped or substantially Z-shaped through groove formed in the first plate body  113 . The second branch flow path  15  is configured of a first communication flow path  15   a  extending in the short direction (X direction in  FIG. 7 ) of the first plate body  113  and opened, and two second communication flow paths  15   b  extending from both ends of the first communication flow path  15   a  in the longitudinal direction (Y direction in  FIG. 7 ) of the first plate body  113  and opened. The first communication flow path  15   a  and the second communication flow path  15   b  are smoothly connected by a bent portion. 
     (Liquid Film Separation Unit  70 ) 
     The form of the liquid film separation unit  70  will be described. 
       FIG. 9  is an enlarged view of the first branch flow path  11  according to Embodiment 1. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  has a vertical portion  70 A formed vertically with respect to the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13 . 
     &lt;Flow of Refrigerant in Layered Header  51 &gt; 
     Next, the confluence flow path  51   a  in the layered header  51  and a flow of refrigerant therein will be described. 
     When the heat exchanger  1  functions as an evaporator, refrigerant in a two-phase gas-liquid flow flows from the first flow path  10 A of the first plate body  111  into the layered header  51 . The refrigerant flowing therein advances straight in the first flow path  10 A, collides with the surface of the second plate body  122  in the first branch flow path  11  of the first plate body  112 , and is divided horizontally in the first communication flow path  12 . 
     The divided refrigerant advances to both ends of the first branch flow path  11  and flows into the pair of second flow paths  10 B. 
     The refrigerant flowing in the second flow path  10 B advances straight in the second flow path  10 B in the same direction as the refrigerant advancing in the first flow path  10 A. The refrigerant collides with the surface of the second plate body  123  in the second branch flow path  15  of the first plate body  113 , and is divided horizontally in the first communication flow path  15   a.    
     The divided refrigerant advances to both ends of the second branch flow path  15 , and flows into four third flow paths  10 C. 
     The refrigerant flowing in the third flow path  10 C advances straight in the third flow path  10 C in the same direction as the refrigerant advancing in the second flow path  10 B. 
     Then, the refrigerant flows out of the third flow path  10 C, and is uniformly divided and flows into the air-upstream side heat transfer tubes  22  of the air-upstream side heat exchanger unit  21 . 
     It should be noted that while an example of the layered header  51  in which refrigerant flows branch flow paths twice and is divided into four in the confluence flow path  51   a  of Embodiment 1 is shown, the number of division is not limited particularly. 
     (Flow of Liquid Refrigerant in First Branch Flow Path  11 ) 
     Here, a flow of liquid refrigerant in the first branch flow path  11  will be described in more detail. 
       FIG. 10  illustrates a flow of liquid refrigerant in a branch flow path in a conventional layered header. 
       FIG. 11  illustrates a flow of liquid refrigerant in the first branch flow path  11  in the layered header  51  according to Embodiment 1. 
     Conventionally, when liquid refrigerant flows in the first branch flow path  11  having the bent portion  14 , a liquid film  20  is formed in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, as illustrated in  FIG. 10 . The liquid film  20  flows through the second communication flow path  13  in a biased manner as it is, and flows into the second flow path  10 B. 
     Meanwhile, in the first branch flow path according to Embodiment 1, the liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13 , as illustrated in  FIG. 11 . The liquid film  20  flowing through the base portion  13 A in a biased manner on the base outer wall portion  13 A- 2  side collides with the liquid film separation unit  70  and the flow path thereof is changed, whereby the liquid film  20  is separated from the base outer wall portion  13 A- 2  and flows through the center of the flow path in the tip portion  13 B. Then, it flows into the second flow path  10 B from substantially the center thereof. 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 1, the liquid film separation unit  70  (vertical portion  70 A) is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, when the liquid film of the liquid refrigerant flows from the base portion  13 A into the tip portion  13 B, it collides with the vertical portion  70 A and is separated from the base outer wall portion  13 A- 2 . Then, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, at the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Thereby, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Embodiment 2 
     In Embodiment 1, the liquid film separation unit  70  is formed as the vertical portion  70 A. In Embodiment 2, the shape of the liquid film separation unit  70  differs from that of Embodiment 1. The other configurations are in common with the distributor, the layered header  51 , the heat exchanger  1 , and the air-conditioning apparatus  91  according to Embodiment 1. Therefore, the description thereof is omitted. 
     &lt;Configuration of Liquid Film Separation Unit  70 &gt; 
       FIG. 12  is an enlarged view of the first branch flow path  11  according Embodiment 2. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  is configured of a combination of two portions, namely a first arcuate portion  70 B and a second arcuate portion  70 C, connecting the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13 . 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 2, the liquid film separation unit  70  (first arcuate portion  70 B and second arcuate portion  70 C) is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, compared with the vertical portion  70 A according to Embodiment 1, it is possible to separate the liquid film from the base outer wall portion  13 A- 2  more smoothly. 
     In that case, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, in the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Therefore, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Further, by constituting the liquid film separation unit  70  of arcuate portions, it is possible to process the first plate body  112  by a drill or an end mill. Therefore, compared with the vertical portion  70 A according to Embodiment 1, the time taken for finishing can be reduced, whereby the productivity is improved. 
     Embodiment 3 
     In Embodiment 1, the liquid film separation unit  70  is formed as the vertical portion  70 A. In Embodiment 3, the shape of the liquid film separation unit  70  differs from that of Embodiment 1. The other configurations are in common with the distributor, the layered header  51 , the heat exchanger  1 , and the air-conditioning apparatus  91  according to Embodiment 1. Therefore, the description thereof is omitted. 
     &lt;Configuration of Liquid Film Separation Unit  70 &gt; 
       FIG. 13  is an enlarged view of the first branch flow path  11  according to Embodiment 3. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  is configured of a tapered portion  70 D having an inclination angle with respect to the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13 . 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 3, the liquid film separation unit  70  (tapered portion  70 D) is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, compared with the vertical portion  70 A according to Embodiment 1, it is possible to separate the liquid film from the base outer wall portion  13 A- 2  more smoothly. 
     In that case, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, in the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Therefore, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Embodiment 4 
     In Embodiment 1, the liquid film separation unit  70  is formed as the vertical portion  70 A. In Embodiment 4, the shape of the liquid film separation unit  70  differs from that of Embodiment 1. The other configurations are in common with the distributor, the layered header  51 , the heat exchanger  1 , and the air-conditioning apparatus  91  according to Embodiment 1. Therefore, the description thereof is omitted. 
     &lt;Configuration of Liquid Film Separation Unit  70 &gt; 
       FIG. 14  is an enlarged view of the first branch flow path  11  according to Embodiment 4. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  is configured as a rectangular recess portion  70 E dented in a rectangular shape with respect to the wall face of the base outer wall portion  13 A- 2  of the second communication flow path  13 . 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 4, the liquid film separation unit  70  (rectangular recess portion  70 E) is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, compared with the vertical portion  70 A according to Embodiment 1, it is possible to separate the liquid film from the base outer wall portion  13 A- 2  more effectively. 
     In that case, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, in the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Therefore, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Embodiment 5 
     In Embodiment 1, the liquid film separation unit  70  is formed as the vertical portion  70 A. In Embodiment 5, the shape of the liquid film separation unit  70  differs from that of Embodiment 1. The other configurations are in common with the distributor, the layered header  51 , the heat exchanger  1 , and the air-conditioning apparatus  91  according to Embodiment 1. Therefore, the description thereof is omitted. 
     &lt;Configuration of Liquid Film Separation Unit  70 &gt; 
       FIG. 15  is an enlarged view of the first branch flow path  11  according to Embodiment 5. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  is configured as a circular recess portion  70 F dented in a circular shape with respect to the wall face of the base outer wall portion  13 A- 2  of the second communication flow path  13 . Further, the tip outer wall portion  13 B- 2  and the circular recess portion  70 F are smoothly connected by a curved portion  70 G. 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 5, the liquid film separation unit  70  (circular recess portion  70 F and curved portion  70 G) is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, compared with the vertical portion  70 A according to Embodiment 1, it is possible to separate the liquid film from the base outer wall portion  13 A- 2  more effectively. 
     In that case, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, in the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Therefore, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Embodiment 6 
     In Embodiment 1, the liquid film separation unit  70  is formed as the vertical portion  70 A. In Embodiment 6, the shape of the liquid film separation unit  70  differs from that of Embodiment 1. The other configurations are in common with the distributor, the layered header  51 , the heat exchanger  1 , and the air-conditioning apparatus  91  according to Embodiment 1. Therefore, the description thereof is omitted. 
     &lt;Configuration of Liquid Film Separation Unit  70 &gt; 
       FIG. 16  is an enlarged view of the first branch flow path  11  according to Embodiment 6. 
     The liquid film separation unit  70  is formed between the base outer wall portion  13 A- 2  and the tip outer wall portion  13 B- 2  of the second communication flow path  13  in the first branch flow path  11 . The liquid film separation unit  70  is configured as an uneven portion  70 H having a surface roughness that is coarser than that of the wall face of the base outer wall portion  13 A- 2  of the second communication flow path  13 . It should be noted that in Embodiment 6, the dimension L 1  and the dimension L 2  of the distances between opposite side walls in the base portion  13 A and the tip portion  13 B are the same length in the second communication flow path  13 . 
     &lt;Effect&gt; 
     According to the layered header  51  (distributor) of Embodiment 6, the liquid film separation unit  70  (uneven portion  70 H) is formed on the base outer wall portion  13 A- 2  of the second communication flow path  13  in the first branch flow path  11 . Accordingly, compared with the vertical portion  70 A according to Embodiment 1, it is possible to separate the liquid film from the base outer wall portion  13 A- 2  with a simpler configuration. 
     In that case, even though the liquid refrigerant flowing from the first flow path  10 A flows in a biased manner on the outer peripheral wall portion  14 - 2  side of the bent portion  14  by the centrifugal force, the flow path of the liquid refrigerant is changed to the tip inner wall portion  13 B- 1  side in the tip portion  13 B, whereby the liquid refrigerant flows through the center of the tip portion  13 B. The liquid refrigerant flows into the second flow path  10 B from the center, and is uniformly distributed with respect to the flow path wall face. Therefore, in the next second branch flow path  15 , the liquid refrigerant is uniformly distributed. 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  10 C) of the confluence flow path  51   a . Therefore, it is possible to improve the heat exchange capacity of the heat exchanger and the air-conditioning apparatus. 
     Embodiment 7 
     In a layered header  251  (distributor) according to Embodiment 7, a configuration of a confluence flow path  251   a  differs from the configuration of the confluence flow path  51   a  according to Embodiment 1. Accordingly, the configuration of the confluence flow path  251   a  will be described. The other configurations are in common with the distributor, the layered header, the heat exchanger, and the air-conditioning apparatus according to Embodiment 1. 
     &lt;Configuration of Layered Header  251 &gt; 
     Hereinafter, a configuration of the layered header  251  of the heat exchanger  1  according to Embodiment 7 will be described. 
       FIG. 17  is an exploded perspective view of the layered header  251  according to Embodiment 7. 
       FIG. 18  is a partial enlarged view of the first branch flow path  211  in the layered header  251  according to Embodiment 7. 
     The layered header  251  (distributor) illustrated in  FIG. 17  is configured of, for example, rectangular first plate bodies  2111 ,  2112 ,  2113 , and  2114 , and second plate bodies  2121 ,  2122 , and  2123  interposed between the respective first plate bodies. The first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 , and  2123  have the same external shape in a planer view. 
     To the first plate bodies  2111 ,  2112 ,  2113 , and  2114  before braze joining, a brazing material is not clad (applied), while on both faces or an either face of the second plate bodies  2121 ,  2122 , and  2123 , a brazing material is clad (applied). From this state, the first plate bodies  2111 ,  2112 ,  2113 , and  2114  are layered via the second plate bodies  2121 ,  2122 , and  2123 , and are heated and brazed in a furnace. Each of the first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 ,  2123  are made of aluminum having a thickness of about 1 to 10 mm, for example. 
     In the layered header  251 , the confluence flow path  251   a  is configured of the flow paths formed by the first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 , and  2123 . The confluence flow path  251   a  includes a first flow path  210 A, a second flow path  210 B, and a third flow path  210 C that are circular through holes, and a first branch flow path  211  and a second branch flow path  216  that are substantially S-shaped or substantially Z-shaped through grooves. 
     It should be noted that each of the plate bodies is processed by pressing or cutting. When it is processed by pressing, a plate material having a thickness of 5 mm or less capable of being processed by pressing is used. When it is processed by cutting, a plate material having a thickness of 5 mm or more may be used. 
     A refrigerant pipe of a refrigeration cycle device is connected to the first flow path  210 A of the first plate body  2111 . The first flow path  210 A of the first plate body  2111  communicates with the connection pipe  52  of  FIG. 1 . 
     At almost the center of the first plate body  2111  and the second plate body  2121 , the circular first flow path  210 A is opened. Further, in the second plate body  2122 , second flow paths  210 B are opened, in a circular shape similarly, at four positions symmetrical with each other with respect to the first flow path  210 A. 
     Furthermore, in the first plate body  2114  and the second plate body  2123 , the third flow paths  210 C are opened in a circular shape at eight positions symmetrical with each other with respect to the second flow path  210 B. The third flow path  210 C of the first plate body  2114  communicates with the air-upstream side heat transfer tube  22  of  FIG. 1 . 
     The first flow path  210 A, the second flow path  210 B, and the third flow path  210 C are positioned and opened to communicate with each other when the first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 , and  2123  are layered. 
     The first plate body  2112  has the first branch flow path  211  and the second branch flow path  216  each of which is a substantially S-shaped or substantially Z-shaped through groove, and the first plate body  2113  has a third branch flow path  215  that is also a substantially S-shaped or substantially Z-shaped through groove. 
     Here, when the respective plate bodies are layered to form the confluence flow path  251   a , the first flow path  210 A is connected to the center of the first branch flow path  11  formed in the first plate body  2112 , and the second branch flow path  216  is connected to both ends of the first branch flow path  211 . 
     Then, the second flow path  210 B is connected to both ends of the second branch flow path  216 . 
     Further, the second flow path  210 B is connected to the center of the third branch flow path  215  formed in the first plate body  113 , and the third flow path  210 C is connected to both ends of the third branch flow path  215 . 
     In this way, by layering and brazing the first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 , and  2123 , the respective flow paths can be connected to form the confluence flow path  251   a.    
     Further, each of the first plate bodies  2111 ,  2112 ,  2113 , and  2114  and the second plate bodies  2121 ,  2122 , and  2123  has a positioning unit  230  for fixing the position when each plate body is layered. 
     Specifically, the positioning unit  230  is formed as a through hole, and positioning can be performed by inserting a pin into the through hole. It is also possible to have a configuration in which a recess is formed on one of plate members opposite to each other and a protrusion is formed on the other one, and the recess and the protrusion are fitted to each other when the two plate materials are layered. 
     (First Branch Flow Path  211 ) 
     Next, the structure of the first branch flow path  211  will be described in detail with use of  FIG. 18 . 
     As described above, the first branch flow path  211  is a substantially S-shaped or substantially Z-shaped through groove formed in the first plate body  2112 . The first branch flow path  211  is formed of a first communication flow path  212  extending in the short direction (X direction in  FIG. 7 ) of the first plate body  2112  and opened, and two second communication flow paths  213  extending from both ends of the first communication flow path  212  in the longitudinal direction (Y direction in  FIG. 7 ) of the first plate body  2112  and opened. The first communication flow path  212  and the second communication flow path  213  are connected smoothly by a bent portion  214 . The second communication flow path  213  is configured of a base portion  213 A connected to the bent portion  214 , and a tip portion  213 B extending from the base portion  213 A in the longitudinal direction (Y direction in  FIG. 7 ) of the first plate body  2112 . 
     The bent portion  214  is configured such that an inner peripheral wall portion  214 - 1  forming a side wall of the inner peripheral side and an outer peripheral wall portion  214 - 2  forming a side wall of the outer peripheral side are provided to face each other. The inner peripheral wall portion  214 - 1  and the outer peripheral wall portion  214 - 2  are configured to form concentric circles, for example. It is configured that the radius of curvature of the inner peripheral wall portion  214 - 1  is smaller than the radius of curvature of the outer peripheral wall portion  214 - 2 . The base portion  213 A of the second communication flow path  213  is configured such that a base inner wall portion  213 A- 1  smoothly extending from the inner peripheral wall portion  214 - 1  of the bent portion  214  and a base outer wall portion  213 A- 2  smoothly extending from the outer peripheral wall portion  214 - 2  of the bent portion  214  are provided to face each other. Further, the tip portion  213 B of the second communication flow path  213  is configured such that a tip inner wall portion  213 B- 1  connected on a straight line to the base inner wall portion  213 A- 1  of the base portion  213 A, and a tip outer wall portion  213 B- 2  connected to the base outer wall portion  213 A- 2  of the base portion  213 A, via a liquid film separation unit  270 , are provided to face each other. In the first communication flow path  212 , the bent portion  214 , and the base portion  213 A of the second communication flow path  213 , a distance between side walls (the inner peripheral wall portion  214 - 1  and the outer peripheral wall portion  214 - 2 , the base inner wall portion  213 A- 1  and the base outer wall portion  213 A- 2 ) facing each other has the same dimension L 1 . A distance (dimension L 2 ) between side walls (the tip inner wall portion  213 B- 1  and the tip outer wall portion  213 B- 2 ) facing each other of the tip portion  213 B is shorter than the dimension L 1 . 
     (Second Branch Flow Path  216 ) 
     Next, the structure of the second branch flow path  216  will be described in detail with use of  FIG. 18 . 
     The second branch flow path  216  is a substantially S-shaped or substantially Z-shaped through groove formed in the first plate body  2112 , as described above. The second branch flow path  216  is configured of a first communication flow path  217  extending in the short direction (X direction in  FIG. 17 ) of the first plate body  2112  and opened, and two second communication flow paths  218  extending from both ends of the first communication flow path  217  in the longitudinal direction (Y direction in  FIG. 17 ) of the first plate body  2112  and opened. 
     Both ends of the first branch flow path  211  are connected to the center of the first communication flow path  217  of the second branch flow path  216 . 
     The first communication flow path  217  and the second communication flow path  218  are smoothly connected to each other via the bent portion  219 . The second communication flow path  218  is configured of a base portion  218 A connected to the bent portion  219 , and a tip portion  218 B extending from the base portion  218 A in the longitudinal direction (Y direction in  FIG. 17 ) of the first plate body  2112 . 
     The bent portion  219  is configured such that an inner peripheral wall portion  219 - 1  forming a side wall of the inner peripheral side and an outer peripheral wall portion  219 - 2  forming a side wall of the outer peripheral side are provided to face each other. The inner peripheral wall portion  219 - 1  and the outer peripheral wall portion  219 - 2  are configured to form concentric circles, for example. It is configured that the radius of curvature of the inner peripheral wall portion  219 - 1  is smaller than the radius of curvature of the outer peripheral wall portion  219 - 2 . The base portion  218 A of the second communication flow path  218  is configured such that a base inner wall portion  218 A- 1  smoothly extending from the inner peripheral wall portion  219 - 1  of the bent portion  219  and a base outer wall portion  218 A- 2  smoothly extending from the outer peripheral wall portion  219 - 2  of the bent portion  219  are provided to face each other. Further, the tip portion  218 B of the second communication flow path  218  is configured such that a tip inner wall portion  218 B- 1  connected on a straight line to the base inner wall portion  218 A- 1  of the base portion  218 A, and a tip outer wall portion  218 B- 2  connected to the base outer wall portion  218 A- 2  of the base portion  218 A, via a liquid film separation unit  370 , are provided to face each other. In the first communication flow path  217 , the bent portion  219 , and the base portion  218 A of the second communication flow path  218 , a distance between side walls (the inner peripheral wall portion  219 - 1  and the outer peripheral wall portion  219 - 2 , the base inner wall portion  218 A- 1  and the base outer wall portion  218 A- 2 ) facing each other has the same dimension L 3 . A distance (dimension L 4 ) between side walls (the tip inner wall portion  218 B- 1  and the tip outer wall portion  218 B- 2 ) facing each other of the tip portion  218 B is shorter than the dimension L 3 . 
     (Third Branch Flow Path  215 ) 
     Next, the structure of the third branch flow path  215  will be described. 
     The third branch flow path  215  is a substantially S-shaped or substantially Z-shaped through groove formed in the first plate body  2113  as described above. The third branch flow path  215  is configured of a first communication flow path  215   a  extending in the short direction (X direction in  FIG. 17 ) of the first plate body  2113  and opened, and two second communication flow paths  215   b  extending from both ends of the first communication flow path  215   a  in the longitudinal direction (Y direction in  FIG. 17 ) of the first plate body  2113  and opened. The first communication flow path  215   a  and the second communication flow path  215   b  are smoothly connected to each other via a bent portion. 
     (Liquid Film Separation Unit  270 ,  370 ) 
     The form of the liquid film separation units  270  and  370  will be described. 
     The liquid film separation unit  270  is formed between the base outer wall portion  213 A- 2  and the tip outer wall portion  213 B- 2  of the second communication flow path  213  in the first branch flow path  211 . Further, the liquid film separation unit  370  is formed between the base outer wall portion  218 A- 2  and the tip outer wall portion  218 B- 2  of the second communication flow path  218  in the second branch flow path  216 . 
     The liquid film separation units  270  and  370  may adopt the forms similar to those of Embodiments 1 to 6. 
     &lt;Flow of Refrigerant in Layered Header  251 &gt; 
     Next, the confluence flow path  251   a  in the layered header  251  and a flow of refrigerant therein will be described. 
     When the heat exchanger  1  functions as an evaporator, refrigerant in a two-phase gas-liquid flow flows from the first flow path  210 A of the first plate body  2111  into the layered header  251 . The refrigerant flowing therein advances straight in the first flow path  210 A, collides with the surface of the second plate body  2122  in the first branch flow path  211  of the first plate body  2112 , and is divided horizontally in the first communication flow path  212 . 
     The divided refrigerant advances to both ends of the first branch flow path  211  and flows into the second branch flow path  216 . The refrigerant flowing in the second branch flow path  216  is divided horizontally in the first communication flow path  217  and advances to both ends of the second branch flow path  216 . Then, the refrigerant flows into the four second flow paths  210 B. 
     The refrigerant flowing in the second flow path  210 B advances straight in the second flow path  210 B in the same direction as the refrigerant advancing in the first flow path  210 A. The refrigerant collides with the surface of the second plate body  2123  in the third branch flow path  215  of the first plate body  2113 , and is further divided horizontally in the first communication flow path  215   a.    
     The divided refrigerant advances to both ends of the third branch flow path  215 , and flows into the eight third flow paths  210 C. 
     The refrigerant flowing in the third flow path  210 C advances straight in the third flow path  210 C in the same direction as the refrigerant advancing in the second flow path  210 B. 
     Then, the refrigerant flows out of the third flow path  210 C, and is uniformly divided and flows into the air-upstream side heat transfer tubes  22  of the air-upstream side heat exchanger unit  21 . 
     It should be noted that while an example in which the refrigerant flows branch flow paths twice and is divided into eight in the layered header  251  is shown in the confluence flow path  251   a  of Embodiment 7, the number of division is not limited particularly. 
     (Flow of Liquid Refrigerant in First Branch Flow Path  211  and Second Branch Flow Path  216 ) 
     Here, a flow of liquid refrigerant in the first branch flow path  211  and the second branch flow path  216  will be described in more detail. 
     As illustrated in  FIG. 18 , in the first branch flow path  211  according to Embodiment 7, the liquid film separation unit  270  is formed between the base outer wall portion  213 A- 2  and the tip outer wall portion  213 B- 2  of the second communication flow path  213 . The liquid film flowing through the base portion  213 A in a biased manner on the base outer wall portion  213 A- 2  side collides with the liquid film separation unit  270  and the flow path thereof is changed, whereby the liquid film is separated from the base outer wall portion  213 A- 2  and flows through the center of the flow path in the tip portion  213 B. Then, it flows into the second branch flow path  216  with no bias of the liquid film. 
     Further, as illustrated in  FIG. 18 , in the second branch flow path  216 , the liquid film separation unit  370  is formed between the base outer wall portion  218 A- 2  and the tip outer wall portion  218 B- 2  of the second communication flow path  218 . The liquid film flowing through the base portion  218 A in a biased manner on the base outer wall portion  218 A- 2  side collides with the liquid film separation unit  370  and the flow path thereof is changed, whereby the liquid film is separated from the base outer wall portion  218 A- 2  and flows through the center of the flow path in the tip portion  218 B. Then, it flows into the second flow path  210 B from the center with no bias of the liquid film. 
     &lt;Effect&gt; 
     According to the layered header  251  (distributor) of Embodiment 7, the liquid film separation unit  270  is formed between the base outer wall portion  213 A- 2  and the tip outer wall portion  213 B- 2  of the second communication flow path  213  in the first branch flow path  211 . Therefore, even though the liquid refrigerant flowing from the first flow path  210 A flows in a biased manner on the outer peripheral wall portion  214 - 2  side of the bent portion  214  by the centrifugal force, the liquid film of the liquid refrigerant collides with the liquid film separation unit  270  when flowing from the base portion  213 A to the tip portion  213 B, and is separated from the base outer wall portion  213 A- 2 . In that case, the flow path of the liquid refrigerant is changed to the tip inner wall portion  213 B- 1  side in the tip portion  213 B, and the liquid refrigerant flows through the center of the tip portion  213 B. As the liquid refrigerant flows into the second branch flow path  216  with no bias of the liquid film, it is uniformly distributed in the first communication flow path  217 . 
     Further, the liquid film separation unit  370  is formed between the base outer wall portion  218 A- 2  and the tip outer wall portion  218 B- 2  of the second communication flow path  218  in the second branch flow path  216 . Therefore, even though the liquid refrigerant flowing from the first branch flow path  211  flows in a biased manner on the outer peripheral wall portion  219 - 2  side of the bent portion  219  by the centrifugal force, the liquid film of the liquid refrigerant collides with the liquid film separation unit  370  when flowing from the base portion  218 A to the tip portion  218 B, and is separated from the base outer wall portion  218 A- 2 . In that case, the flow path of the liquid refrigerant is changed to the tip inner wall portion  218 B- 1  side in the tip portion  218 B, and the liquid refrigerant flows through the center of the tip portion  218 B. As the liquid refrigerant flows into the second flow path  10 B from the center and is uniformly distributed with respect to the flow path wall, the liquid refrigerant is uniformly distributed in the next third branch flow path  215 . 
     Accordingly, it is possible to uniformly supply the refrigerant at the flow path outlet (third flow path  210 C) of the confluence flow path  251   a , whereby it is possible to improve the heat exchange capacity of the heat exchanger  1  and the air-conditioning apparatus  91 . 
     It should be noted that while Embodiment 7 illustrates an example in which the liquid film separation units  270  and  370  are provided on the two branch flow paths namely the first branch flow path  211  and the second branch flow path  216  respectively, it is possible to provide either one of the liquid film separation units  270  and  370 . It is also possible to provide only the liquid film separation unit  370  of the second branch flow path  216  that highly affects uniform distribution of the liquid refrigerant in the third branch flow path  215 . 
     Embodiments 1 to 7 illustrate examples in which the number of the first plate bodies and the second plate bodies interposed between the respective first plate bodies is seven in total. However, the number of the plate bodies is not limited particularly. Further, the number of divisions of the branch flow paths is not limited to those described in the embodiments. 
     Further, while, in Embodiments 1 to 7, the layered headers  51  and  251  are described as examples, the configurations of the liquid film separation units  70 ,  270 , and  370  described in Embodiments 1 to 7 may be applicable to the flow paths of a distribution device or a distributor utilizing more general pipes. 
     &lt;Effects of Present Invention&gt; 
     (1) A distributor according to the present invention includes one first flow path  10 A,  210 A, and a first branch flow path  11 ,  211  for dividing the first flow path  10 A,  210 A into a plurality of second flow paths  10 B,  210 B. The first branch flow path  11 ,  211  is configured to include a first communication flow path  12 ,  212 ,  217  communicating with the first flow path  10 A,  210 A, a second communication flow path  13 ,  213 ,  218  communicating with each of the second flow paths  10 B,  210 B, and a bent portion  14 ,  214 ,  219  connecting the first communication flow path  12 ,  212 ,  217  and the second communication flow path  13 ,  213 ,  218 . The bent portion  14 ,  214 ,  219  includes an inner peripheral wall portion  14 - 1 ,  214 - 1 ,  219 - 1  including an inner face having a first radius of curvature, and an outer peripheral wall portion  14 - 2 ,  214 - 2 ,  219 - 2  including an inner face having a second radius of curvature larger than the first radius of curvature. The second communication flow path  13 ,  213 ,  218  includes an inner wall portion extending from the inner peripheral wall portion  14 - 1 ,  214 - 1 ,  219 - 1  of the bent portion  14 ,  214 ,  219 , and an outer wall portion extending from the outer peripheral wall portion  14 - 2 ,  214 - 2 ,  219 - 2  of the bent portion. In the outer wall portion, a liquid film separation unit  70 ,  270 ,  370  is formed. 
     As such, even though the liquid refrigerant flowing from the first flow path  10 A,  210 A flows in a biased manner on the outer peripheral side of the bent portion  14 ,  214 ,  219  by the centrifugal force, the liquid film of the liquid refrigerant collides with the liquid film separation unit  70 ,  270 ,  370  and is separated from the outer wall portion of the second communication flow path  13 ,  213 ,  218 . The flow path of the liquid refrigerant is changed to the inner wall portion side of the second communication flow path  13 ,  213 ,  218 , and the liquid refrigerant flows through the center of the flow path. Then, the liquid refrigerant flows into the second flow path  10 B,  210 B from the center and is uniformly distributed with respect to the flow path wall face, whereby the liquid refrigerant is uniformly distributed in the next branch flow path. 
     (2) The distributor according to the present invention includes a first flow path  210 A, a first branch flow path  211  for dividing the first flow path  210 A, and a plurality of second branch flow paths  216  for dividing the first branch flow path  211  into a second flow path  210 B. The second branch flow path  216  is configured to include a first communication flow path  217  communicating with the first branch flow path  211 , a second communication flow path  218  communicating, at one end side thereof, with the second flow path  210 B, and a bent portion  219  connecting the first communication flow path  217  and the second communication flow path  218 . The bent portion  219  includes an inner peripheral wall portion  219 - 1  including an inner face having a first radius of curvature, and an outer peripheral wall portion  219 - 2  including an inner face having a second radius of curvature larger than the first radius of curvature. The second communication flow path  218  includes an inner wall portion extending from the inner peripheral wall portion  219 - 1  of the bent portion  219 , and an outer wall portion extending from the outer peripheral wall portion  219 - 2  of the bent portion  219 . In the outer wall portion, the liquid film separation unit  370  is formed. 
     As such, even though the liquid refrigerant flowing from the first branch flow path  211  into the second branch flow path  216  flows in a biased manner on the outer peripheral side of the bent portion  219  by the centrifugal force, the liquid film of the liquid refrigerant collides with the liquid film separation unit  370  and is separated from the outer wall portion of the second communication flow path  218 . The flow path of the liquid refrigerant is changed to the inner wall portion side of the second communication flow path  218 , and the liquid refrigerant flows through the center of the flow path. Then, the liquid refrigerant flows into the second flow path  210 B from the center and is uniformly distributed with respect to the flow path wall face, whereby the liquid refrigerant is uniformly distributed in the next branch flow path. 
     (3) The liquid film separation unit  70 ,  270 ,  370  of the distributor according to the present invention is formed as a protruding portion on the outer wall portion of the second communication flow path  13 ,  213 ,  218  in the distributor described in (1) or (2). Accordingly, the liquid film separation unit  70 ,  270 ,  370  serves as a flow path resistance against fluid to thereby be able to separate the liquid film from the outer wall portion. 
     (4) The liquid film separation unit  70 ,  270 ,  370  of the distributor according to the present invention is formed as a recess portion on the outer wall portion of the second communication flow path  13 ,  213 ,  218  in the distributor described in (1) or (2). Accordingly, the liquid film separation unit  70 ,  270 ,  370  serves as a flow path resistance against the fluid to thereby be able to separate the liquid film from the outer wall portion. 
     (5) The distributor according to the present invention is the distributor according to (1) to (4) in which a dimension between the inner wall portion and the outer wall portion of the second communication flow path  13 ,  213 ,  218  is configured such that one end side, that is, the bent portion  14 ,  214 ,  219  side, of the second communication flow path  13 ,  213 ,  218  is larger than the other end side of the second communication flow path  13 ,  213 ,  218 , with the liquid film separation unit  70 ,  270 ,  370  being the boundary. Accordingly, the liquid film separation unit  70 ,  270 ,  370  is formed as a stepped portion and serves as a flow path resistance against the fluid to thereby be able to separate the liquid film from the outer wall portion. 
     (6) The distributor according to the present invention is the distributor according to (1) to (5) including one second flow path of a plurality of second flow paths and a third branch flow path connecting the one second flow path and a plurality of third flow paths. As such, when the liquid refrigerant flows into the third flow paths, the liquid refrigerant can be distributed uniformly. 
     (7) The layered header  51 ,  251  according to the present invention is configured of the distributor according to (1) to (6), in which at least a first plate body in which the first flow path  10 A,  210 A is opened, a second plate body in which the first branch flow path  11 ,  211  is opened, and a third plate body in which the second flow path  10 B,  210 B is opened, are layered integrally. Therefore, the distributor according to (1) to (6) can be configured as the layered header  51 ,  251 , whereby a confluence flow path  51   a ,  251   a  of the distributor can be formed easily. 
     (8) The heat exchanger  1  according to the present invention includes the distributor according to (1) to (6) and a plurality of heat transfer tubes, in which the plurality of heat transfer tubes and the distributor are connected to each other. Therefore, it is possible to uniformly supply the liquid refrigerant to the respective heat transfer tubes of the heat exchanger  1 , and to improve the heat conductive performance of the heat exchanger  1 . 
     (9) The heat exchanger  1  according to the present invention includes the layered header  51 ,  251  according to (7) and a plurality of heat transfer tubes, in which the heat transfer tubes and the layered header  51 ,  251  are connected to each other. Therefore, it is possible to uniformly supply the liquid refrigerant to the respective heat transfer tubes of the heat exchanger  1 , and to improve the heat conductive performance of the heat exchanger  1 . 
     (10) The air-conditioning apparatus  91  according to the present invention includes the heat exchanger  1  according to (8) or (9). Therefore, as the heat conductive performance of the heat exchanger  1  is improved, the performance of the air-conditioning apparatus  91  can be improved.