WO2023152789A1

WO2023152789A1 - Heat exchanger

Info

Publication number: WO2023152789A1
Application number: PCT/JP2022/004859
Authority: WO
Inventors: 伸中村; 悟梁池; 進一内野; 智広飛田
Original assignee: 三菱電機株式会社
Priority date: 2022-02-08
Filing date: 2022-02-08
Publication date: 2023-08-17

Abstract

This heat exchanger comprises: a first divider for dividing refrigerant into a plurality of flows; one or more second dividers for furthermore dividing one of the plurality of flows of refrigerant divided by the first divider into a plurality of flows; and a plurality of heat transfer pipes arranged in the center-of-gravity direction, the plurality of heat transfer pipes constituting three or more refrigerant paths. The second dividers each have a connection part that is part of the three or more refrigerant paths and that connects together the heat transfer pipes constituting the plurality of refrigerant paths, the connection parts each having a plurality of refrigerant flow channels formed in the interior thereof, and an opening connected to the first divider being formed in each of the connection parts. One heat transfer pipe among the plurality of heat transfer pipes is connected to the first divider via the one or more second dividers and constitutes one or more groups of a plurality of first refrigerant paths into which the plurality of flows of refrigerant divided by any of the one or more second dividers flow. The remaining heat transfer pipes among the plurality of heat transfer pipes are connected to the first divider directly without interposition of the one or more second dividers and constitute one or more second refrigerant paths into which one of the plurality of flows of refrigerant divided by the first divider directly flows.

Description

Heat exchanger

The present disclosure relates to heat exchangers with distributors.

In a heat exchanger, in order to reduce the pressure loss in the heat transfer tube due to the reduction in the diameter of the heat transfer tube or the increase in the number of holes in the flat tube, the number of flow path branches in the heat exchanger, that is, the number of refrigerant paths is increased. is common. The heat exchanger includes a distributor that distributes refrigerant to each refrigerant path. Such a heat exchanger includes a first distributor (for example, a distributor) that branches the flow of the refrigerant into a plurality of flows, and a U-shaped pipe portion in order to reduce the number of branches of the distributor. There is one that further includes two distributors (see, for example, Patent Document 1).

Japanese Patent No. 6278904

In the heat exchanger of Patent Document 1, all refrigerant paths provided in multiple stages in the direction of gravity are connected to the distributor via the second distributor. Therefore, in the heat exchanger of Patent Document 1, due to the second distributors provided in all the refrigerant paths, there is little space on the side of the heat exchanger where the second distributors are provided, and the heat exchanger It was difficult to perform work such as brazing during manufacturing or installation.

The present disclosure has been made in order to solve the above-described problems, and it is an object of the present disclosure to provide a heat exchanger having a second distributor with good workability during manufacture, assembly, and maintenance. aim.

A heat exchanger according to the present disclosure includes: a first distributor that distributes a refrigerant into a plurality of flows; One or more second distributors for distribution, and a plurality of stages of heat transfer tubes arranged in the direction of gravity and forming three or more refrigerant paths, wherein the second distributor includes the three or more refrigerant paths A connection portion having a plurality of refrigerant flow paths formed therein, which is a part of the refrigerant path and connects the heat transfer tubes constituting a plurality of refrigerant paths, and the connection portion includes the first and an opening connected to the distributor is formed, and some of the heat transfer tubes of the plurality of stages are connected to the first distributor via the one or more second distributors one or more groups of a plurality of first refrigerant paths into which the plurality of flows of the refrigerant distributed by any one of the one or more second distributors are connected, and the plurality of stages of heat transfer tubes The remaining heat transfer tubes are connected to the first distributor without passing through the one or more second distributors, and are connected to the plurality of flows of the refrigerant distributed by the first distributor Configure one or more secondary refrigerant paths, one of which flows directly into.

In the heat exchanger of the present disclosure, some of the multiple stages of heat transfer tubes are connected to the first distributor via one or more second distributors, and among the multiple stages of heat transfer tubes, The remaining heat transfer tubes are connected to the first distributor without passing through the second distributor. Therefore, according to the present disclosure, a second distributor in the heat exchanger is provided compared to the conventional case where all refrigerant paths are connected to the first distributor via the second distributor. A space is created on the side, and the heat exchanger with the second distributor can be manufactured and assembled, and the workability during maintenance is improved.

1 is a refrigerant circuit diagram of a refrigeration cycle device including a heat exchanger according to Embodiment 1. FIG. 1 is a schematic diagram showing a configuration example of an outdoor unit equipped with a heat exchanger according to Embodiment 1; FIG. FIG. 3 is an exploded perspective view of the outdoor unit of FIG. 2; FIG. 2 is a schematic diagram schematically showing the configuration of the heat exchanger according to Embodiment 1 as seen from the windward side; FIG. 5 is a schematic diagram of a configuration example of the second distributor of FIG. 4 as viewed from the leeward side; Figure 6 is a schematic side view of the second distributor of Figure 5; Figure 6 is a schematic view from above of the second distributor of Figure 5; FIG. 5 is a schematic diagram showing one configuration example of a joint in the heat exchanger of FIG. 4; FIG. 5 is a partial enlarged view of the heat exchanger of FIG. 4; FIG. 10 is a side view of the heat exchanger of FIG. 9 viewed from the side where the second distributor is provided; FIG. 5 is a schematic diagram schematically showing a refrigerant distribution structure in the heat exchanger of FIG. 4; FIG. 4 is a schematic diagram of a first modification of the heat exchanger according to Embodiment 1; FIG. 13 is a partially enlarged view including the upper end portion of the heat exchanger of FIG. 12; FIG. 14 is a side view of the heat exchanger of FIG. 13 as seen from the side where the second distributor is provided; FIG. 5 is a schematic diagram of a second modification of the heat exchanger according to Embodiment 1; FIG. 16 is a side view of the heat exchanger of FIG. 15 viewed from the side where the second distributor is provided; FIG. 8 is a schematic diagram of a third modification of the heat exchanger according to Embodiment 1; FIG. 18 is a side view of the heat exchanger of FIG. 17 viewed from the side where the second distributor is provided; FIG. 7 is a schematic diagram schematically showing a partial configuration of a heat exchanger according to Embodiment 2 as viewed from the windward side; FIG. 20 is a side view of the heat exchanger of FIG. 19 viewed from the side where the second distributor is provided; FIG. 20 is a schematic diagram showing a configuration example of the second distributor of FIG. 19 as viewed from the leeward side; Figure 22 is a schematic side view of the second distributor of Figure 21; Figure 22 is a schematic view from above of the second distributor of Figure 21; FIG. 11 is a schematic diagram of a fourth modification of the heat exchanger according to Embodiment 2; FIG. 25 is a side view of the heat exchanger of FIG. 24 as seen from the side where the second distributor is provided;

Embodiment 1.
FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle device 1 including a heat exchanger 10 according to Embodiment 1. FIG. The refrigeration cycle device 1 has a refrigerant circuit 1C that transfers heat using the latent heat of evaporation and condensation of the refrigerant. As the refrigerating cycle device 1, for example, there is an air conditioner that performs indoor heating and cooling. In FIG. 1 , the dotted arrows indicate the direction of refrigerant flow when the refrigeration cycle device 1 performs cooling operation and dehumidifying operation, and the solid arrows indicate the direction of refrigerant flow when the refrigeration cycle device 1 performs heating operation. is shown. First, the configuration of the refrigeration cycle device 1 will be described with reference to FIG.

As shown in FIG. 1, the refrigeration cycle device 1 includes a compressor 2, an indoor heat exchanger 3, an indoor fan 4, an expansion device 5, a heat exchanger 10, an outdoor fan 6, and a four-way valve 7. and have. For example, the compressor 2 , the heat exchanger 10 , the expansion device 5 and the four-way valve 7 are provided in the outdoor unit 101 , and the indoor heat exchanger 3 is provided in the indoor unit 102 .

The compressor 2, the indoor heat exchanger 3, the throttle device 5, the heat exchanger 10, and the four-way valve 7 are connected by refrigerant piping to form a refrigerant circuit 1C in which the refrigerant circulates. In the refrigerating cycle device 1, a refrigerating cycle is performed in which the refrigerant circulates in the refrigerant circuit 1C while changing its phase.

The compressor 2 sucks in low-pressure gas refrigerant, compresses it, converts it into high-pressure gas refrigerant, discharges it, and circulates it in the refrigerant circuit 1C. The compressor 2 is, for example, a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or the like.

The indoor heat exchanger 3 functions as a condenser during heating operation and as an evaporator during cooling operation. The indoor heat exchanger 3 is, for example, a fin-and-tube heat exchanger, a microchannel heat exchanger, a finless heat exchanger, a shell-and-tube heat exchanger, a heat pipe heat exchanger, or a double-tube heat exchanger. or a plate heat exchanger.

The expansion device 5 expands and decompresses the refrigerant. The expansion device 5 is, for example, an electric expansion valve or the like that can adjust the flow rate of the refrigerant. The expansion device 5 may be not only an electric expansion valve, but also a mechanical expansion valve employing a diaphragm as a pressure receiving portion, or each connecting pipe or the like.

The heat exchanger 10 functions as an evaporator during heating operation and as a condenser during cooling operation. The heat exchanger 10 is composed of, for example, a fin-and-tube heat exchanger. Details of the heat exchanger 10 will be described later.

The four-way valve 7 switches the refrigerant flow path in the refrigeration cycle device 1 . The four-way valve 7 is switched to connect the discharge port of the compressor 2 and the indoor heat exchanger 3 and connect the suction port of the compressor 2 and the heat exchanger 10 during the heating operation. Further, the four-way valve 7 is switched to connect the discharge port of the compressor 2 and the heat exchanger 10 and connect the suction port of the compressor 2 and the indoor heat exchanger 3 during the cooling operation and the dehumidifying operation. . Instead of using the four-way valve 7, a configuration may be adopted in which a plurality of valves are used to switch the flow path of the refrigerant.

The configuration of the refrigerant circuit 1C is not limited to the above configuration. For example, the four-way valve 7 may be omitted from the refrigerant circuit 1C, and the refrigeration cycle device 1 may be configured to perform only the heating operation.

The indoor fan 4 is attached to the indoor heat exchanger 3, and supplies the room air as a heat exchange fluid to the indoor heat exchanger 3. The outdoor fan 6 is attached to the heat exchanger 10 and supplies outdoor air to the heat exchanger 10 .

The operation of the refrigeration cycle device 1 will be described with reference to FIG. A four-way valve 7 switches between heating and cooling. In heating operation, the refrigerant discharged from the compressor 2 flows through the indoor heat exchanger 3, the expansion device 5, and the heat exchanger 10 in this order, and returns to the compressor 2. FIG. On the other hand, in cooling operation, the refrigerant discharged from the compressor 2 flows through the heat exchanger 10 , the expansion device 5 and the indoor heat exchanger 3 in this order, and returns to the compressor 2 . Among the indoor heat exchanger 3 and the heat exchanger 10, the condenser radiates the heat of the high-temperature and high-pressure gas refrigerant to the outside air and condenses it into liquid refrigerant. Among the indoor heat exchanger 3 and the heat exchanger 10, the evaporator causes the liquid refrigerant contained in the low-temperature, low-pressure refrigerant to absorb heat from the outside air and evaporate it.

FIG. 2 is a schematic diagram showing a configuration example of the outdoor unit 101 equipped with the heat exchanger according to the first embodiment. The white arrows in FIG. 2 indicate the direction of air flow during operation. 3 is an exploded perspective view of the outdoor unit of FIG. 2. FIG. The outdoor unit 101 according to Embodiment 1 will be described with reference to FIGS. 2 and 3. FIG.

As shown in FIGS. 2 and 3, the outdoor unit 101 has, for example, a cuboid shape. The outdoor unit 101 includes, for example, a top panel 111, a side panel 112, a front panel 113, a fan grill 114, a bottom panel 115 and side covers . The top panel 111 constitutes the top surface of the outdoor unit 101, the side panel 112 constitutes the right side of the outdoor unit 101 in FIG. The bottom panel 115 constitutes the bottom of the outdoor unit 101 . An air outlet is formed in the front surface of the front panel 113, and a grid-like fan grill 114 is provided to cover the outlet. A side cover 116 is attached to the outside of the side panel 112 . As shown in FIG. 3, these structures and the heat exchanger 10 surround the refrigerant circuit components (for example, the compressor 2, the expansion device 5 and the four-way valve 7) arranged on the outdoor unit 101 side. ing. Moreover, in the example shown in FIG. 3, the outdoor fan 6 is also arranged inside the outdoor unit 101 . The outdoor fan 6 is composed of, for example, a propeller fan or the like.

As indicated by the white arrows in FIG. 2, the airflow flowing into the heat exchanger 10 is directed from the back side to the front side of the heat exchanger 10, that is, from the upper right direction of FIG. flow. Airflow drawn by the outdoor fan 6 (see FIG. 3) passes through the heat exchanger 10 (see FIG. 3). Moreover, in the example shown in FIG. 3, the heat exchanger 10 has an L-shape in a plan view, and is arranged on the side rear side and the rear side of the housing 9 . Note that the configuration of the outdoor unit 101 is not limited to the configuration described above.

FIG. 4 is a schematic diagram schematically showing the configuration of the heat exchanger 10 according to Embodiment 1 as seen from the windward side. In FIG. 4, the dotted line arrows indicate the direction of refrigerant flow when the refrigeration cycle device 1 performs the cooling operation and the dehumidifying operation using the heat exchanger 10 (see FIG. 1) as a condenser. It shows the direction in which the refrigerant flows when the refrigerating cycle device 1 performs the heating operation using the exchanger 10 (see FIG. 1) as an evaporator. FIG. 5 is a schematic diagram showing a configuration example of the second distributor 30 of FIG. 4 as viewed from the leeward side. FIG. 6 is a schematic side view of the second distributor 30 of FIG. FIG. 7 is a schematic top view of the second distributor 30 of FIG. FIG. 8 is a schematic diagram showing one configuration example of a joint in the heat exchanger 10 of FIG. 9 is a partially enlarged view of the heat exchanger 10 of FIG. 4. FIG. FIG. 10 is a side view of the heat exchanger 10 of FIG. 9 viewed from the side where the second distributor 30 is provided. In FIGS. 6, 7 and 10, white arrows indicate the direction of air flow. A virtual line X3 in FIG. 6 is a virtual line in the direction of gravity, that is, in the vertical direction (direction of arrow Z).

The configuration of the heat exchanger 10 will be described based on FIGS. 4 to 10. FIG. In FIG. 3, the heat exchanger 10 has a curved portion and is provided from the side rear side to the back side of the outdoor unit 101, but in the following description, for ease of understanding, the heat exchanger 10 It is defined as having a rectangular parallelepiped shape along the back of the machine 101 .

In the following description, directional terms (e.g., "up", "down", "right", "left", "front", "back", etc.) are used as appropriate for ease of understanding. For the purpose of description, these terms are not intended to limit this disclosure. Unless otherwise specified, these directional terms mean the directions when the heat exchanger 10 is viewed from the windward side (the rear side of the outdoor unit 101 shown in FIG. 2) as shown in FIG. there is

As shown in FIG. 4, the heat exchanger 10 includes a plurality of plate-like fins 11 stacked with a space therebetween, and a plurality of heat transfer tubes that penetrate the plate-like fins 11 in the stacking direction and have a refrigerant flowing therein. 12 and. The heat transfer tubes 12 are, for example, circular tubes or flat tubes made of copper or aluminum. In addition, the heat exchanger 10 includes a distribution structure that distributes the refrigerant when the heat exchanger 10 functions as an evaporator, and a header 50 that joins the refrigerant after heat exchange in the plurality of heat transfer tubes 12. there is Specifically, heat exchanger 10 includes a first distributor 20 that distributes the refrigerant into multiple streams when heat exchanger 10 functions as an evaporator, and a first distributor 20 that distributes the refrigerant into multiple streams when heat exchanger 10 functions as an evaporator. and one or more second distributors 30 for further distributing the refrigerant distributed by the first distributor 20 into two streams. The heat exchanger 10 includes a header 50 that joins the refrigerant evaporated in the plurality of heat transfer tubes 12 . Header 50 has a plurality of header branch pipes 51 .

In the following description, for ease of understanding, as shown in FIG. 4, the stacking direction of the plate-like fins 11 and the longitudinal direction of the heat transfer tubes 12 are the lateral direction (direction of arrow X) of the heat exchanger 10. , the longitudinal direction of the plate-like fins 11 is defined as the vertical direction (direction of arrow Z) of the heat exchanger 10, that is, the direction of gravity. The plurality of heat transfer tubes 12 are arranged in the longitudinal direction of the plate-like fins 11, that is, in the gravitational direction.

In the examples shown in FIGS. 4, 9 and 10, the plurality of heat transfer tubes 12 are arranged in two rows in the direction of air flow (indicated by white arrows in FIG. 2), as shown in the side view of FIG. are arranged so that That is, as shown in FIGS. 9 and 10, some of the plurality of heat transfer tubes 12 are arranged on the windward side in the air circulation direction (arrow Y direction) and spaced apart from each other. The heat transfer tubes 12 are arranged in the vertical direction (direction of arrow Z), and the remaining heat transfer tubes of the plurality of heat transfer tubes 12 are arranged on the leeward side and arranged in the vertical direction (direction of arrow Z) with a space therebetween. The heat transfer tubes 12 belonging to the windward row may be referred to as windward heat transfer tubes 12a, and the heat transfer tubes 12 belonging to the leeward row may be referred to as leeward heat transfer tubes 12b. In the following description, the arrangement of the heat transfer tubes 12 or refrigerant paths in the gravitational direction may be referred to as a stage. In the heat exchanger 10, the multistage heat transfer tubes 12 may be provided in three or more rows, or may be provided in one row.

The heat exchanger 10 shown in FIGS. 4, 9 and 10 includes an interstage connection pipe 13 connecting two vertically adjacent heat transfer tubes 12 belonging to the same row, and a heat transfer pipe belonging to the windward row. 12 and an inter-row connection pipe 14 that connects the heat transfer tubes 12 belonging to the row on the leeward side. In the example shown in FIG. 4, the inter-stage connection pipe 13 connects the right ends of two vertically adjacent heat transfer tubes 12, and the row-to-row connection pipe 14 connects the left ends of the upwind heat transfer tubes 12a and the downwind side. It is connected to the left end of the heat transfer tube 12b. As shown in FIG. 4 , a plurality of heat transfer tubes 12 are connected to interstage connection pipes 13 and interrow connection pipes 14 so that a flow path, that is, a refrigerant path is formed inside the plurality of heat transfer tubes 12 connected in series. is formed. In the examples shown in FIGS. 4, 9 and 10, one refrigerant path is configured by a total of four heat transfer tubes 12, two windward heat transfer tubes 12a and two leeward heat transfer tubes 12b. Specifically, each refrigerant path is formed by four heat transfer tubes 12 , two inter-stage connection pipes 13 , and one inter-row connection pipe 14 .

It should be noted that the configuration of the refrigerant path is not limited to the configuration described above. For example, the heat exchanger 10 may have a configuration in which a plurality of stages of heat transfer tubes 12 arranged in the vertical direction are arranged in one row, and three or more rows of heat transfer tubes 12 are provided in the air circulation direction. When the heat exchanger 10 has three or more rows of multistage heat transfer tubes 12, each of the refrigerant paths includes, for example, two stages of heat transfer tubes 12 connected to each other in each row and a plurality of interrow connection pipes 14. , can be configured by The inter-row connection pipe 14 connects one of the two-stage heat transfer tubes 12 in one of the multiple rows and one of the two-stage heat transfer tubes in a row different from any of the rows. For example, in the case where the heat exchanger 10 has a plurality of stages of heat transfer tubes 12 arranged in the first row, the second row, and the third row in order from the windward side in the air flow direction, each refrigerant path is divided into two An inter-row connecting pipe 14 is included. In this case, one inter-row connecting pipe 14 connects, for example, the heat transfer tubes 12 of the first row and the heat transfer tubes 12 of the second row. The other inter-row connecting pipe 14 connects the heat transfer tubes 12 in the second row, which are different from the heat transfer tubes 12 connected to the heat transfer tubes 12 in the first row, to the heat transfer tubes 12 in the third row.

As shown in FIG. 4, each of the inter-stage connection pipes 13 and the inter-row connection pipes 14 is composed of a member different from the heat transfer pipes 12, and is connected to the heat transfer pipes 12 by, for example, brazing. . Note that each of the inter-stage connection pipe 13 and the inter-row connection pipe 14 may be formed integrally with the heat transfer pipe 12 penetrating through the plate-like fins 11 .

One end sides of some of the three or more refrigerant paths of the heat exchanger 10 are each connected to a second distributor 30 , and the second distributor 30 is connected to the first refrigerant path via a connecting pipe 40 . is connected to the distributor 20 of . Moreover, one end sides of the remaining refrigerant paths among the three or more refrigerant paths of the heat exchanger 10 are connected to the first distributor 20 via connection pipes 40 respectively. The connection pipe 40 is, for example, a capillary tube. Further, the other end sides of the three or more refrigerant paths of the heat exchanger 10 are connected to the header main pipe 52 via the header branch pipes 51 respectively.

Hereinafter, among the three or more refrigerant paths of the heat exchanger 10, the two refrigerant paths connected to the first distributor 20 via the second distributor 30 are referred to as the first

refrigerant paths

61a and 61 b , and the two first

refrigerant paths

61 a and 61 b may be collectively referred to as a first refrigerant path group 61 . In addition, among the three or more refrigerant paths that the heat exchanger 10 has, the refrigerant path that is directly connected to the first distributor 20 via the connecting pipe 40 without passing through the second distributor 30 is referred to as the second refrigerant. Sometimes referred to as path 62 . As shown in FIG. 4 , in the heat exchanger 10 of the present disclosure, the multiple stages of refrigerant paths arranged in the direction of gravity include a first refrigerant path group 61 and a second refrigerant path 62 . It's becoming

The first distributor 20 is, for example, a distributor, and as the flow of the refrigerant is indicated by solid arrows in FIG. is divided into the total number of the second distributors 30 and the number of the second refrigerant paths 62 , that is, the number of connection pipes 40 . The second distributor 30 is, for example, a three-way pipe distributor, and when the heat exchanger 10 is used as an evaporator, the refrigerant that has been divided by the first distributor 20 and has flowed through the first connecting pipe is Further split into two.

Here, the operation when the heat exchanger 10 is used as an evaporator will be described with reference to FIGS. 1 and 4. FIG. The gas-liquid two-phase refrigerant flow that has flowed out of the expansion device 5 shown in FIG. 1 first flows into the first distributor 20 shown in FIG. 4, is divided, and is sprayed down. The diverted and atomized refrigerant flows into each connecting pipe 40 . Among the plurality of connection pipes 40, the refrigerant that has flowed into the connection pipe 40 connected to the second distributor 30 passes through this connection pipe, flows into the second distributor 30, and in the second distributor 30 Further, the refrigerant branches out and flows into the heat transfer tubes 12 of the two first refrigerant paths 61a and 62b. In addition, the refrigerant that has flowed into the connection pipe 40 that is directly connected to the heat transfer pipe 12 among the plurality of connection pipes 40 passes through the connection pipe 40 and then directly flows into one second refrigerant path 62 without being branched. . The refrigerant that has flowed into each refrigerant path exchanges heat with air while passing through the plurality of heat transfer tubes 12 that make up the refrigerant path, becomes a gaseous state, and flows out of the refrigerant path. The gaseous refrigerant flowing out from each refrigerant path passes through the header branch pipe 51 and merges in the header main pipe 52 . The gaseous refrigerant that joins at the header 50 flows out of the heat exchanger 10 through a refrigerant port (not shown) provided in the header main pipe 52 . The gaseous refrigerant that has flowed out of the heat exchanger 10 then passes through the four-way valve 7 and is sucked into the compressor 2 as shown in FIG.

As described with reference to FIG. 4, the heat exchanger 10 includes one or more second distributors 30 in addition to the first distributor 20, so that the refrigerant flowing into the heat exchanger 10 is Compared to the configuration where only the first distributor 20 branches, the refrigerant can be distributed to many refrigerant paths. In addition, since the heat exchanger 10 is configured such that only some of the three or more refrigerant paths are connected to the first distributor 20 via the second distributor 30, the conventional As compared with the configuration in which all refrigerant paths are connected to the distributor through the second distributor, it is easier to secure a working space. As shown in FIGS. 4 and 10, especially when the inter-row connection pipe 14 and the header branch pipe 51 are provided on the side of the heat exchanger 10 where the second distributor 30 is provided (on the left side in FIG. 4), Structure becomes complicated. However, in the heat exchanger 10 of the present disclosure, the heat transfer tubes 12 of the second refrigerant path 62 are not connected to the second distributor 30 configured by a three-way pipe distributor or the like, and are connected to the direct connection pipe 40. Therefore, the structure is simplified and the working space is secured. Therefore, for example, when the second distributor 30 is brazed to the heat transfer tubes 12, interference with other structures is less likely to occur than in the conventional art. Further, for example, when connecting the connecting pipe to the second distributor 30, interference between the connecting pipe and other structures is suppressed more than in the conventional case. Therefore, the workability of the heat exchanger 10 of the present disclosure is better than that of the conventional one.

The structure of the second distributor 30 will be described in detail based on FIGS. 5 to 7 and with reference to FIGS. 4, 8 and 10. FIG. As shown in FIG. 5 , the second distributor 30 has a U-shaped tube portion 31 formed by bending a circular tube into a U-shape, and an inflow portion 35 . The U-shaped tube portion 31 connects the two first

refrigerant paths

61a and 61b. The U-shaped tube portion 31 has a U-shaped connecting portion 32 and two

arm portions

33 and 34 extending parallel to each other from both ends of the connecting portion 32 . Both ends of the U-shaped tube portion 31 in the second distributor 30, that is, the tips of the two

arm portions

33 and 34 are connected to the heat transfer tubes 12 of the two first

refrigerant paths

61a and 61b. The connection between the arm portion 33 and the first refrigerant path 61a and the connection between the arm portion 34 and the first refrigerant path 61b are directly connected if the heat transfer tube 12 is a circular tube, and the heat transfer tube 12 is a flat tube. If so, they are connected via a joint 15 (see FIG. 8).

As shown in FIG. 5 , an opening C is formed in the wall of the U-shaped pipe portion 31 , and an inflow portion 35 is provided in the opening C of the U-shaped pipe portion 31 . The inflow part 35 is provided so as to extend upward from the opening C, and the opening C is connected to the first distributor (see FIG. 4) via the inflow part 35 . The shape of the inflow portion 35 is a straight tube shape, that is, an annular shape along the edge of the opening portion C. As shown in FIG. The inflow portion 35 is provided so as to be substantially perpendicular to the tube axis of the U-shaped tube portion 31 . The inflow portion 35 is formed, for example, by bulging the pipe wall of the upper arm portion 33 of the U-shaped pipe portion 31 . Bulge forming is a process in which a pipe-shaped material is first set in a mold inside a press, then the mold is clamped, and then while filling the material with high-pressure liquid, both ends of the material are compressed in the axial direction so that they approach each other. It is a processing method that stretches the material into the shape carved in the mold and performs hollow molding.

Refrigerant flows from the inflow portion 35 into the U-shaped tube portion 31 through the opening C, and the inflowed refrigerant collides with the inner surface of the tube wall of the U-shaped tube portion 31 and is divided into two flows to form two arms. Distributed from openings A and B at the tips of 33 and 34 are two

first coolant paths

61a and 61b (FIG. 4). Here, an example in which the inflow portion 35 is provided in the upper arm portion 33 is shown, but the portion in which the inflow portion 35 is provided in the U-shaped tube portion 31 is not particularly limited to this. However, it is preferable to provide the inflow portion 35 in the

linear arm portion

33 or 34 .

The second distributor 30 shown in FIG. 5 has an inflow piping 36 extending linearly longer than the inflow 35 . One end of the inlet pipe 36 is attached to the inlet 35, and the other end of the inlet pipe 36 is connected to the connection pipe 40 (see FIG. 4). One end of the inflow pipe 36 is attached to the inflow portion 35 by, for example, being inserted into the inflow portion 35 and brazed. In Embodiment 1, the U-shaped pipe portion 31, the inflow portion 35, and the inflow pipe 36 are configured separately. good. In Embodiment 1, the inflow pipe 36 and the connection pipe are configured separately, but the end of the connection pipe may be linear to constitute the inflow pipe 36 .

In the heat exchanger 10 (see FIG. 4), the second distributor 30 is arranged such that the two

arms

33 and 34 extend in the horizontal direction, and the refrigerant flowing into the arm 33 from the inflow portion 35 flows in the horizontal direction. It is configured to branch and flow. In other words, in the second distributor 30, the angle _θ1 between the pipe axis X1 of the inflow portion 35 formed in the upper arm portion 33 and the pipe axis X2 of the upper arm portion 33 is approximately 90°. An inflow portion 35 is formed in the . Although the angle θ ₁ does not have to be strictly 90°, for example, if the angle θ ₁ deviates from 90° by more than 15°, the refrigerant flowing from the inflow portion 35 into the arm portion 33 will flow into the arm portion 33 . It collides obliquely with the inner surface of the pipe wall and drifts. In this case, the refrigerant cannot be evenly distributed to the two first

refrigerant paths

61 a and 61 b connected to the U-shaped tube portion 31 . In the heat exchanger 10 (see FIG. 4), the two first

refrigerant paths

61a and 61b (FIG. 4) connected by the U-shaped tube portion 31 are arranged vertically, and the difference in wind speed between them is not so great. None. That is, the design heat exchange amount between the two is almost the same. Therefore, if the refrigerant flowing into the two first

refrigerant paths

61a and 61b (see FIG. 4) is unbalanced, the state of the refrigerant flowing out of each refrigerant path after heat exchange will vary, resulting in deterioration of heat exchange efficiency. Resulting in. Therefore, the angle θ ₁ at which the inflow portion 35 is provided in the U-shaped pipe portion 31 is preferably 75° or more and 105° or less.

In addition, since the refrigerant flowing into the heat exchanger 10 is a two-phase flow when the heat exchanger 10 is used as an evaporator as indicated by solid arrows in FIG. For this reason, when the refrigerant flows into the second distributor 30, the liquid portion of the refrigerant becomes uneven. Therefore, when the refrigerant flowing into the second distributor 30 collides with the inner surface of the pipe wall of the arm portion 33 of the U-shaped pipe portion 31 and branches off, if the run-up section is not sufficient, the two first refrigerant paths 61a and The amount and state of the refrigerant that divides into 61b and flows in is uneven. Therefore, in the heat exchanger 10 of the first embodiment, the length of the straight pipe through which the refrigerant is branched in the second distributor 30, that is, the length of the inlet pipe 36 is set to 10 times the inner diameter. That's it. As a result, by ensuring a sufficient length of the run-up section, the flow of the refrigerant can be sufficiently stabilized without bias, which is effective for uniform distribution of the refrigerant. In addition, in the heat exchanger 10 of the present disclosure, the inflow pipe 36 can be extended and provided in the space created by not providing the second distributor 30, and the length of the linear run-up section can be secured. Therefore, it is possible to further suppress the drift of the refrigerant.

In addition, as shown in FIG. 6, the inlet section is arranged such that the angle θ ₂ between the imaginary line X3 in the direction of gravity in the side view and the tube axis X1 of the inlet section 35 is −90°<angle θ ₂ <90°. 35 are molded. Here, it is defined that the angle _θ2 is 0° when the pipe axis X1 of the inflow portion 35 extends straight upward in the direction of gravity from the U-shaped pipe portion 31, and the pipe axis X1 of the inflow portion 35 is inclined to the leeward side. A negative angle is defined as a positive angle, and a positive angle is defined as a windward inclination. That is, the inflow part 35 is provided upward in a side view. The tube axis of the inlet pipe 36 coincides with the tube axis X1 of the inlet 35 . In the example shown in FIGS. 6 and 10, the inflow portion 35 is provided on the upper arm portion 33 so that the angle _θ2 of the inflow portion 35 in side view is −30°, and the inflow portion 35 is inclined to the leeward side. It is installed facing upwards.

As shown in FIG. 6, when the second distributor 30 has an inflow portion 35 provided upward at the opening C of the U-shaped pipe portion 31, interference with the header branch pipe 51 (see FIG. 10) is suppressed. Further, in the case where the U-shaped tube portion 31 provided with the inflow portion 35 and the inflow portion piping 36 are configured separately, the U-shaped tube portion 31 is brazed to the heat transfer tube 12 (see FIG. 4). In the configuration in which the inflow pipe 36 is brazed to the inflow portion 35 after that, the inflow portion 35 is provided facing upward, thereby improving the brazeability. If the inflow part 35 is provided downward, the inflow part pipe 36 is likely to fall off due to its own weight when the inflow part pipe 36 is inserted into the inflow part 35 and brazed. Since the pipe 36 is difficult to fall off, the brazing work can be easily performed. Further, when the inflow portion 35 is provided upward, when the inflow portion pipe 36 is inserted into the inflow portion 35 and brazed, the solder is likely to enter the gap between the inflow portion 35 and the inflow portion pipe 36. The joint strength with the inlet pipe 36 can be ensured.

The configuration of the second distributor 30 is not limited to the configuration described above. For example, the second distributor 30 may be configured to distribute the refrigerant to two or more first refrigerant paths. part. An opening C connected to the first distributor 20 is formed in the connecting portion. When distributing the refrigerant to three or more first refrigerant paths, instead of the U-shaped pipe portion 31, the number of branch pipes corresponding to the number of connected first refrigerant paths may be used as the connecting portion. can be done. Alternatively, the connecting portion may be configured such that the internal space is partitioned into a plurality of coolant channels.

FIG. 11 is a schematic diagram schematically showing the refrigerant distribution structure in the heat exchanger 10 of FIG. The configurations of the first distributor 20 and the connecting pipe 40 will be described in detail with reference to FIGS. 4 and 11. FIG. In the following description, among the plurality of connection pipes 40, the one that connects the first distributor 20 and the second distributor 30 is referred to as the first connection pipe 41, and the first connection pipe 41 and the second distributor 20 , which connects the refrigerant path 62 with the heat transfer tube 12 may be referred to as a second connection pipe 42 .

When the heat exchanger 10 is used as an evaporator, the first distributor 20 evenly distributes the refrigerant that has flowed into the first distributor 20 in a gas-liquid two-phase state to each heat transfer tube 12 of the heat exchanger 10. It is required to branch to In particular, it is required to allow the refrigerant to flow into a plurality of refrigerant paths in a similar refrigerant state. For this reason, a distributor is used as the first distributor 20 in the example shown in FIG. Although not shown, a throttle mechanism such as an orifice is provided inside the distributor, and by allowing the inflowing two-phase flow to pass through the orifice, it is turned into a spray flow state, making it easy to distribute evenly. The atomized refrigerant is evenly distributed to each connecting pipe 40 . Distributors are made of copper, aluminum, brass, or the like. It should be noted that the distributor may be of a specification that does not have a throttle mechanism such as an orifice therein. The first distributor 20 may be any device as long as it can evenly distribute the refrigerant.

Each connecting pipe 40 can adjust the pressure loss in the pipe according to the specifications such as the inner diameter and length, and can adjust the division ratio from the first distributor 20 to each heat transfer pipe 12 or the second distributor 30 . In general, it is known that the friction loss ΔP _f [Pa] in a pipe through which a gas single-phase refrigerant flows, that is, the pressure loss is represented by the following equation (1).

f: Friction loss coefficient of pipe L: Length of flow path [m]
De: Hydraulic diameter of pipe [m]
ρ _v : Density of gas single-phase refrigerant [kg/m ³ ]
u: flow velocity of fluid flowing in pipe [m/s]

　The friction loss coefficient f of a pipe is generally expressed by the following formula in the case of turbulent flow (Reynolds number of 3000 or more).

Re: Reynolds number μ _v : Viscosity of gas single phase [Pa s]

Also, the refrigerant circulation amount Gr can be calculated by the following formula (4).

From the above equations (1) to (4), the state quantities that contribute to the friction loss ΔP _f [Pa] in the pipe are calculated as follows.

That is, the friction loss ΔP _f [Pa] in the pipe is proportional to the 1.75th power of the refrigerant circulation amount, the 1st power of the pipe length, and the −4.75th power of the hydraulic diameter in the pipe. When the refrigerant flows in a two-phase state of liquid and gas, the pressure loss increases. However, since attention is paid to the fact that it is shown from the dimensional relationship here, this increase is ignored.

As shown in FIG. 4, each first connecting pipe 41 is connected to two first

refrigerant paths

61a and 61b via a second distributor 30, and each second connecting pipe 42 is connected to one It is directly connected with two second refrigerant paths 62 . Refrigerant distribution in the heat exchanger 10 is such that the refrigerant circulation amount Gr is basically distributed such that the pressure loss is the same. When the heat exchanger 10 has the same number of heat transfer tubes 12 in each row (see FIG. 10), two vertically adjacent refrigerant paths (for example, the first refrigerant path 61a and the second refrigerant path 61a shown in FIG. 11) 62 and ), the heat load applied to each refrigerant path is assumed to be similar. In this case, by evenly flowing the refrigerant circulation amount Gr through the two vertically adjacent refrigerant paths, it is possible to prevent the refrigerant from gasifying first in one of the refrigerant paths and degrading the performance. That is, the refrigerant circulation amount Gr is evenly passed through the refrigerant paths (for example, the first refrigerant path 61a, the first refrigerant path 61b, and the second refrigerant path 62 in FIG. 11) to which the same heat load is applied. is desirable.

Here, in order to evenly flow the refrigerant circulation amount Gr through the first refrigerant path 61a, the first refrigerant path 61b, and the second refrigerant path 62 to which the same heat load is applied, the first connection It is conceivable to flow through the pipe 41 twice the amount of refrigerant that flows through the second connection pipe 42 . However, when the specifications of the first connecting pipe 41 and the second connecting pipe 42 are the same, as shown in the equation (5), the pressure loss is proportional to the 1.75th power of the refrigerant circulation amount Gr. In order to equalize the pressure loss (that is, the friction loss ΔP _f ) in the first connection pipe 41 and the second connection pipe 42, the circulation amount of the refrigerant flowing through the first connection pipe 41 is It is less than twice the amount of circulation flowing through the pipe 42 . Therefore, the refrigerant circulation amount per path of the first refrigerant path group 61 becomes smaller than the refrigerant circulation amount of the second refrigerant path 62, and the refrigerant distribution with respect to the heat load becomes uneven.

Therefore, in the heat exchanger 10 of the present disclosure, by adjusting the pressure loss in the pipes according to the dimensional relationship between the first connecting pipe 41 and the second connecting pipe 42, the first refrigerant path 61a and the first refrigerant path Refrigerant circulation amount Gr can be evenly flowed through 61 b and second refrigerant path 62 . Specifically, the first connection pipe 41 and the second connection pipe 42 are used such that the pressure loss in the first connection pipe 41 is smaller than the pressure loss in the second connection pipe 42. . More specifically, the length of the second connection pipe 42 is made longer than the length of the first connection pipe 41, or the inner diameter D2 of the second connection pipe 42 is set to the length of the first connection pipe 41. It should be smaller than the inner diameter D1.

By the way, the wind speed from the outdoor fan 6 (see FIG. 1) that blows air to the heat exchanger 10 is not necessarily uniform over the entire surface of the heat exchanger 10 shown in FIG. 4, and there may be a wind speed distribution. . When the heat exchanger 10 is used as an evaporator, the refrigerant passing through the portion of the heat exchanger 10 where the wind speed is fast gasifies and dries more easily than the refrigerant passing through the portion of the heat exchanger 10 where the wind speed is slow. Therefore, when the amount of refrigerant flowing into each heat transfer tube 12 is the same, the refrigerant that has passed through the portion where the wind speed is fast has a higher degree of dryness than the refrigerant that has passed through the portion where the wind speed is slow, and the refrigerant state varies at the outlet of the heat exchanger. occurs. In general, when the refrigerant gasifies, the heat exchange efficiency deteriorates significantly. Therefore, if the wind speed varies depending on the part of the heat exchanger 10, a large amount of the refrigerant flows into the heat transfer tube 12 located in the part where the wind speed is high. By dividing the flow into two, the state of the refrigerant at the outlet of the refrigerant path is made to be the same among the refrigerant paths. In this way, even when it is required to adjust the flow division ratio due to the existence of the wind speed distribution, it is possible to adjust the flow division ratio by adjusting the specifications of each connecting pipe 40 .

As described above, the heat exchanger 10 of Embodiment 1 includes the first distributor 20 that distributes the refrigerant into a plurality of flows, and one of the plurality of flows of the refrigerant distributed by the first distributor 20. and one or more second distributors 30 for further distributing one into a plurality of streams. The heat exchanger 10 also includes multiple stages of heat transfer tubes 12 that are arranged in the direction of gravity and form three or more refrigerant paths. The second distributor 30 is a connection portion (for example, , a U-shaped tube portion 31), and an opening portion C connected to the first distributor 20 is formed in the connecting portion. Some of the heat transfer tubes 12 of the multiple stages of heat transfer tubes 12 are connected to the first distributor 20 via one or more second distributors 30, and are connected to one or more second distributors. One or more groups of a plurality of first

refrigerant paths

61a and 61b into which a plurality of flows of refrigerant distributed by any of 30 flow. The remaining heat transfer tubes 12 of the multi-stage heat transfer tubes 12 are connected to the first distributor 20 without passing through one or more second distributors 30, and the refrigerant distributed by the first distributor 20 constitutes one or more second refrigerant paths 62 directly into which one of the plurality of flows of .

In the heat exchanger 10 of Embodiment 1, only some of the heat transfer tubes 12 (the plurality of heat transfer tubes 12 forming the first

refrigerant paths

61a and 61b) of the multiple stages of heat transfer tubes 12 are connected to the second distributor. 30 is provided. Therefore, in the heat exchanger 10 of the present disclosure, the second distributor 30 is provided in the heat exchanger 10 compared to the conventional case where the second distributor 30 is provided in all of the plurality of refrigerant paths. Creates space on the sides. As a result, in the heat exchanger 10 having the second distributor 30, workability such as pipe assembly and brazing is improved.

In addition, the heat exchanger 10 includes a first connection pipe 41 that connects the first distributor 20 and the second distributor 30, and heat transfer pipes 12 between the first distributor 20 and the second refrigerant path 62. and a second connection pipe 42 that connects the . The first connection pipe 41 and the second connection pipe 42 are configured such that the pressure loss in the first connection pipe 41 is smaller than the pressure loss in the second connection pipe 42 .

As a result, of the first connection pipe 41 and the second connection pipe 42, the refrigerant flows more easily through the first connection pipe 41, which is connected to the larger number of refrigerant paths. can be done. Therefore, the distribution ratio for the heat load of the heat exchanger 10 can be brought close to an appropriate value.

Modified examples of the heat exchanger 10 according to Embodiment 1 are given below. FIG. 12 is a schematic diagram of a first modification of the heat exchanger 10 according to Embodiment 1. FIG. In FIG. 12, the dotted line arrows indicate the direction of refrigerant flow when the refrigeration cycle device 1 (see FIG. 1) performs the cooling operation and the dehumidifying operation using the heat exchanger 10 as a condenser, and the solid line arrows indicate the direction of heat exchange. 1 shows the direction in which the refrigerant flows when the refrigerating cycle device 1 (see FIG. 1) performs heating operation using the evaporator 10 as an evaporator. FIG. 13 is a partially enlarged view including the upper end of the heat exchanger 10 of FIG. 12. FIG. 14 is a side view of the heat exchanger of FIG. 13 viewed from the side where the second distributor is provided. In FIG. 14, white arrows indicate the direction of air flow. The configuration of the heat exchanger 10 of the first modified example will be described with reference to FIGS. 12 to 14. FIG.

As shown in FIG. 12 , in the heat exchanger 10 of the first modification, only the refrigerant path positioned at the uppermost stage in the gravitational direction among the three or more refrigerant paths of the heat exchanger 10 is the second refrigerant. The first refrigerant path 61a or the first refrigerant path 61b is the refrigerant path of the second stage or lower. That is, in the heat exchanger 10 of the first modified example, the uppermost refrigerant path is directly connected to the first distributor 20 by the connection pipe 40 without the second distributor 30 interposed therebetween. In addition, not only the uppermost refrigerant path among the three or more refrigerant paths that the heat exchanger 10 has, but also some of the second and lower refrigerant paths may be used as the second refrigerant paths 62 .

Thus, in the first modification, the second refrigerant path 62 is arranged at the uppermost position in the gravitational direction of the three or more refrigerant paths that the heat exchanger 10 has. By not providing the second distributor 30 in the upper part, a space is created. Therefore, a work space for brazing the uppermost second distributor 30 to the heat transfer tubes 12 can be secured. Further, as shown in FIGS. 13 and 14, the second distributor 30 is provided so as to be connected to the second stage or lower refrigerant paths among the three or more refrigerant paths that the heat exchanger 10 has. , the inflow part 35 and the inflow part pipe 36 of the second distributor 30 can be prevented from protruding above the heat exchanger 10 . Therefore, compared to the conventional case where the second distributor 30 is provided at the uppermost stage of a plurality of refrigerant paths, in the heat exchanger 10 of the first modification, the second distributor 30 and the outdoor unit 101 (Fig. 2 ), the height of the outdoor unit 101 can be lowered, or the inlet piping 36 of the second distributor 30 located at the uppermost side can be lengthened.

Further, as shown in FIG. 12, among the plurality of connection pipes 40 extending from the first distributor 20, the connection pipe 40 extending from the position furthest from the plurality of heat transfer tubes 12 is connected to the uppermost refrigerant path. By doing so, it is possible to avoid interference with other connecting pipes 40 and facilitate handling. Therefore, the manufacturability of the heat exchanger 10 is improved.

FIG. 15 is a schematic diagram of a second modification of the heat exchanger 10 according to Embodiment 1. FIG. In FIG. 15, white arrows indicate the direction of air flow. FIG. 16 is a side view of the heat exchanger 10 of FIG. 15 viewed from the side where the second distributor 30 is provided. The configuration of the heat exchanger 10 of the second modification will be described with reference to FIGS. 15 and 16. FIG.

As shown in FIG. 16, in the heat exchanger 10 of the second modification, as in the case of the first modification, among the three or more refrigerant paths that the heat exchanger 10 has, the refrigerant path located in the uppermost stage is the second refrigerant path 62 and is directly connected to the connecting pipe 40 . In the second modification, the inter-row connecting pipes 14a of the refrigerant paths positioned at the topmost stage are the heat transfer tubes 12 arranged at the topmost stage of the windward row and the heat transfer tubes 12 arranged at the topmost stage of the leeward row. 12 and are connected. In the heat exchanger 10 of the second modification, among the row-to-row connection pipes 14 (see FIG. 15) in three or more refrigerant paths, the row-to-row connection pipe 14a constituting the uppermost refrigerant path is It is provided so as to protrude most in the lateral direction (direction of arrow X) of the heat exchanger 10 . That is, the horizontal length La of the row-to-row connection pipe 14a constituting the second refrigerant path 62 arranged on the uppermost stage as viewed from the windward side is the width of the row-to-row connection pipe 14 constituting the other refrigerant paths. It is configured to be longer than the length Lo in the direction. In the heat exchanger 10 of the second modification, the inter-row connection pipe 14a, which is located at the uppermost position among the plurality of inter-row connection pipes 14 and has the longest horizontal length, is composed of, for example, a thermistor. A temperature detector 71 is installed.

Thus, in the second modification, the row-to-row connection pipe 14 of the second refrigerant path 62 located at the uppermost stage is provided on the upper side of the second refrigerant path 62, It protrudes in the lateral direction of the heat exchanger 10 more than the connecting pipe 14 . Therefore, it becomes easy to install the temperature detector 71 in the inter-row connection pipe 14a while avoiding interference with other pipes.

In addition, when each of the refrigerant paths is provided with two or more inter-row connection pipes 14, such as when the heat exchanger 10 has three or more rows of heat transfer tubes 12 in multiple stages, the second Only one of the two or more inter-row connection pipes 14 included in the refrigerant path 62 may be configured to protrude in the lateral direction of the heat exchanger 10 .

Also, in the example shown in FIGS. 15 and 16, the plurality of windward heat transfer tubes 12a and the plurality of leeward heat transfer tubes 12b are arranged to be shifted in the direction of gravity. All of the second distributors 30 are connected to two heat transfer tubes 12 in a row (in the example shown in FIG. 15, the row on the windward side) that is displaced downward in the direction of gravity. All of the header branch pipes 51 are connected to the heat transfer tubes 12 in other rows (the row on the lee side in the example shown in FIG. 15).

In the case where the inflow portion 35 and the inflow portion piping 36 of the second distributor 30 are provided to extend upward as shown in FIG. Interference between the header branch pipe 51 and the inlet pipe 36 can be suppressed by providing the pipe 30 . Specifically, in FIG. 15, the inlet pipe 36 in the second distributor 30 connected to the second refrigerant path from the top (the first refrigerant path 61a shown in FIG. 16) is connected to the second distributor 30 Since the row on the windward side where is provided is shifted downward from the row on the leeward side, it is connected to the uppermost refrigerant path (second refrigerant path 62 shown in FIG. 16) provided in the row on the leeward side. The distance from the header branch pipes 51 is greater than when the two rows are provided at the same height, and interference can be suppressed.

FIG. 17 is a schematic diagram of a third modification of the heat exchanger 10 according to Embodiment 1. FIG. FIG. 18 is a side view of the heat exchanger 10 of FIG. 17 viewed from the side where the second distributor 30 is provided. In FIG. 18, white arrows indicate the direction of air flow. The configuration of the heat exchanger 10 of the third modification will be described with reference to FIGS. 17 and 18. FIG.

As shown in FIG. 17, in the heat exchanger 10 of the third modification, a plurality of first refrigerant paths (for example, two first

refrigerant paths

61a and 61b) and a second refrigerant path 62 are arranged alternately. In the third modification, the first refrigerant path group 61 and the second refrigerant path are provided alternately in the gravitational direction, so as shown in FIG. Compared to the case where they are arranged continuously in the direction of the arrow Z, there is more space between the

second distributors

30 and 30 . Therefore, the workability of assembling and joining (for example, brazing) pipes is improved.

Embodiment 2.
FIG. 19 is a schematic diagram schematically showing a partial configuration of the heat exchanger 10 according to Embodiment 2 as viewed from the windward side. FIG. 20 is a side view of the heat exchanger 10 of FIG. 19 viewed from the side where the second distributor 30 is provided. FIG. 21 is a schematic diagram showing one configuration example of the second distributor 30 of FIG. 19 as viewed from the leeward side. FIG. 22 is a schematic side view of the second distributor 30 of FIG. FIG. 23 is a schematic top view of the second distributor 30 of FIG. In FIGS. 20, 22 and 23, white arrows indicate the direction of air flow.

In the first embodiment, the inflow part 35 in the second distributor 30 is provided so as to extend upward from the opening C of the U-shaped tube part 31, which is the connecting part. The portion 35 is provided so as to extend horizontally from the opening portion C of the U-shaped pipe portion 31, which is a connecting portion. In the second embodiment, the configuration different from that of the first embodiment will be described below.

As shown in FIGS. 20 and 22, in the heat exchanger 10 of the second embodiment, the second distributor 30 has an inflow portion 35 provided laterally in the U-shaped tube portion 31 in side view. That is, the inflow portion 35 and the opening portion C are arranged on the leeward side of the U-shaped pipe portion 31 so that the angle _θ2 between the imaginary line X3 in the direction of gravity and the tube axis X1 of the inflow portion 35 is −90° in a side view. is provided. Further, as shown in FIG. 23, the inflow portion 35 is provided so that the angle _θ1 between the upper arm portion 33 and the tube axis X2 is approximately 90°. That is, in the examples shown in FIGS. 20 to 23, the linear inlet pipe 36 is provided to extend downwind along the air circulation direction.

As shown in FIG. 20, a plurality of heat transfer tubes provided in the windward row (that is, the windward heat transfer tubes 12a shown in FIG. 19) and a plurality of heat transfer tubes 12 provided in the leeward row (that is, FIG. 19 12b) and the leeward heat transfer tubes 12b) are arranged with a deviation in the direction of gravity. The second distributor 30 is connected to the two heat transfer tubes 12 belonging to the windward row (that is, the windward heat transfer tubes 12a shown in FIG. 19) and extends downstream from the U-shaped tube portion 31. The internal pipe 36 is arranged between two header branch pipes 51 .

In addition, in the U-shaped tube portion 31 shown in FIG. 21 , the portion where the inflow portion 35 is provided is not limited to the upper arm portion 33 , and may be provided in the connecting portion 32 or the lower arm portion 34 . In addition, the inflow part 35 and the inflow part pipe 36 may be provided in the horizontal direction, and may be provided upstream of the U-shaped pipe part 31 so that the angle _θ2 is 90°, or may be provided as shown in FIG. It may be provided in the lateral direction (the direction of the arrow X) when viewed from the windward side. When the inflow part 35 and the inflow part pipe 36 are provided in the lateral direction (the direction of the arrow X) when viewed from the windward side, the opening C, the inflow part 35 and the inflow part pipe 36 are provided in the connection part 32 of the U-shaped pipe part 31. be done. Also, the angle θ ₁ does not have to be strictly 90°, but is preferably 75° or more and 105° or less.

As shown in FIG. 19 , also in the heat exchanger 10 of the second embodiment, three or more refrigerant paths of the heat exchanger 10 are routed through the first distributor 30 via the second distributor 30 . 20, and a second refrigerant path 62 directly connected to the first distributor 20 without going through the second distributor 30. Therefore, since the second distributor 30 is provided only in some of the three or more refrigerant paths of the heat exchanger 10, the side of the heat exchanger 10 on which the second distributor 30 is provided A space is created in the space, and workability such as piping assembly and brazing is improved.

Further, in the heat exchanger 10 of Embodiment 2, the second distributor 30 has an inflow portion 35 extending horizontally from the opening C of the connecting portion (for example, the U-shaped pipe portion 31), and the opening Section C is connected via inlet section 35 to the first distributor. As a result, the inflow portion 35 can be provided without changing the vertical width of the second distributor 30. Therefore, even if the interval, that is, the pitch, between the heat transfer tubes 12 arranged in the vertical direction (the arrow Z direction) is narrow, A run-up section for the refrigerant before branching can be provided while avoiding interference between the second distributor 30 and other pipes.

FIG. 24 is a schematic diagram of a fourth modification of the heat exchanger 10 according to Embodiment 2. FIG. FIG. 25 is a side view of the heat exchanger 10 of FIG. 24 viewed from the side where the second distributor 30 is provided. In FIG. 25, white arrows indicate the direction of air flow. The configuration of the heat exchanger of the fourth modification will be described with reference to FIGS. 24 and 25. FIG.

Also in the heat exchanger 10 of the fourth modification, the inflow part 35 of the second distributor 30 is provided horizontally in the U-shaped tube part 31, as in the cases shown in FIGS. However, in the heat exchanger 10 of the fourth modification, the inflow portion 35 is provided so as to face the side opposite to the side where the plurality of header branch pipes 51 are arranged in the air circulation direction. In the example shown in FIGS. 24 and 25, each of the plurality of header branch pipes 51 is connected to the windward row of heat transfer tubes 12 (that is, the windward heat transfer tubes 12a shown in FIG. 24) to form the second distribution The vessel 30 is connected to the leeward row of heat transfer tubes 12 (ie, the leeward heat transfer tubes 12b shown in FIG. 24). The inflow portion 35 of the second distributor 30 is provided on the leeward side of the U-shaped pipe portion 31 in the air circulation direction, and an inflow pipe 36 extends from the inflow portion 35 along the air circulation direction. there is

As described above, the heat exchanger 10 of the fourth modification has a plurality of header branch pipes 51 and includes the header 50 in which refrigerant from three or more refrigerant paths of the heat exchanger 10 join together. A plurality of stages of heat transfer tubes 12 are provided in the direction of air flow. Each of the plurality of header branch pipes 51 is connected to the heat transfer tubes 12 arranged in one row among the plurality of rows, and the second distributor 30 connects two heat transfer tubes arranged in one row among the plurality of rows. It is connected to the heat tube 12 . The inflow portion 35 extends to the side opposite to the side on which the plurality of header branch pipes 51 are arranged in the air circulation direction.

Thus, in the heat exchanger 10 of the fourth modification, the inflow portion 35 is provided in the U-shaped pipe portion 31 in the horizontal direction, and the plurality of header branch pipes 51 are arranged in the air circulation direction. It is provided so as to face the side opposite to the side. Therefore, even in the heat exchanger 10 having a narrow pitch between the upper and lower heat transfer tubes 12 and having a two-row structure, the second distributor 30 and the second distributor 30, and the second distributor 30 and the header branch pipe 51 interference can be suppressed, and workability is good.

It should be noted that each embodiment can be combined, or each embodiment can be modified or omitted as appropriate.

REFERENCE SIGNS LIST 1 Refrigeration cycle device 1C Refrigerant circuit 2 Compressor 3 Indoor heat exchanger 4 Indoor fan 5 Expansion device 6 Outdoor fan 7 Four-way valve 9 Case 10 Heat exchanger 11 Plate fin 12 heat transfer tube 12a windward heat transfer tube 12b leeward heat transfer tube 13 inter-stage connection pipe 14 inter-row connection pipe 14a inter-row connection pipe 15 joint 20 first distributor 30 second distributor, 31 U-shaped tube portion, 32 connection portion, 33 arm portion, 34 arm portion, 35 inflow portion, 36 inflow portion pipe, 40 connection pipe, 41 first connection pipe, 42 second connection pipe, 50 header, 51 header branch pipe 52 header main pipe 61 first refrigerant path group 61a first refrigerant path 61b first refrigerant path 62 second refrigerant path 71 temperature detector 101 outdoor unit 102 indoor unit 111 Top panel 112 Side panel 113 Front panel 114 Fan grill 115 Bottom panel 116 Side cover A Opening C Opening D1 Inside diameter D2 Inside diameter Gr Refrigerant circulation amount X1 Tube axis X2 Tube axis X3 virtual line, f friction loss coefficient, ΔP _f friction loss, θ ₁ angle, θ ₂ angle.

Claims

a first distributor for distributing the refrigerant into multiple streams;
one or more second distributors for further distributing one of the plurality of flows of the refrigerant distributed by the first distributor into a plurality of flows;
A multi-stage heat transfer tube arranged in the direction of gravity and constituting three or more refrigerant paths,
The second distributor has a connecting portion formed therein with a plurality of refrigerant flow paths, which is a part of the three or more refrigerant paths and connects the heat transfer tubes constituting the plurality of refrigerant paths. and the connecting portion is formed with an opening connected to the first distributor,
Some of the heat transfer tubes in the plurality of stages are connected to the first distributor via the one or more second distributors, and any one of the one or more second distributors configuring one or more groups of a plurality of first refrigerant paths into which the plurality of flows of the refrigerant distributed by
The remaining heat transfer tubes of the plurality of stages of heat transfer tubes are connected to the first distributor without passing through the one or more second distributors, and the refrigerant distributed by the first distributor comprising one or more second refrigerant paths into which one of said plurality of streams of the heat exchanger directly enters.
The heat exchanger according to claim 1, wherein the second refrigerant path is arranged on the uppermost side of the three or more refrigerant paths in the gravitational direction.
A plurality of rows of the heat transfer tubes of the plurality of stages are provided in the direction of air flow,
each of the three or more refrigerant paths,
two stages of heat transfer tubes connected to each other in each row;
An inter-row connection pipe connecting one of the two stages of heat transfer tubes in one of the plurality of rows and one of the two stages of heat transfer tubes in a row different from any of the rows ,
The row-to-row connection pipe constituting the second refrigerant path arranged on the uppermost side in the gravitational direction is different from the heat transfer pipe arranged on the uppermost stage in any of the rows. connecting the heat transfer tubes arranged at the top of the row,
The horizontal length of the row-to-row connection pipe that constitutes the second refrigerant path arranged on the uppermost side when viewed from the windward side is the horizontal length of the row-to-row connection pipe that constitutes the other refrigerant paths. 3. The heat exchanger of claim 2, longer than the length.
The heat exchanger according to any one of claims 1 to 3, wherein the plurality of first refrigerant paths and the plurality of second refrigerant paths are alternately arranged in the gravitational direction.
the second distributor has an inflow portion extending upward from the opening of the connecting portion;
The heat exchanger according to any one of claims 1 to 4, wherein the opening is connected to the first distributor via the inlet.
Two rows of the multi-stage heat transfer tubes are provided in the direction of air flow,
The plurality of stages of heat transfer tubes in the windward row and the plurality of stages of heat transfer tubes in the leeward row are arranged with a shift in the direction of gravity,
6. The heat exchanger according to claim 5, wherein the second distributor is connected to two rows of heat transfer tubes that are displaced downward in the gravitational direction.
the second distributor has an inlet extending horizontally from the opening of the connection;
The heat exchanger according to any one of claims 1 to 6, wherein the opening is connected to the first distributor via the inlet.
a header having a plurality of header branch pipes, where the refrigerant from the three or more refrigerant paths joins;
A plurality of rows of the heat transfer tubes of the plurality of stages are provided in the direction of air flow,
each of the plurality of header branch pipes is connected to a heat transfer tube arranged in one of the plurality of rows,
The second distributor is connected to two heat transfer tubes arranged in a row different from the one row of the plurality of rows,
8. The heat exchanger according to claim 7, wherein the inflow portion extends in a direction opposite to the side where the plurality of header branch pipes are arranged in the air circulation direction.
a first connection pipe that connects the first distributor and the second distributor;
a second connection pipe that connects the first distributor and the heat transfer pipe that constitutes the second refrigerant path,
2. The first connecting pipe and the second connecting pipe are configured such that pressure loss in the first connecting pipe is smaller than pressure loss in the second connecting pipe. 9. The heat exchanger according to any one of -8.