HEAT EXCHANGER AND AIR CONDITIONER

Abstract

An outdoor heat exchanger includes: a group of windward flat tubes, a group of leeward flat tubes and a distributor. When the outdoor heat exchanger acts as an evaporator, the refrigerant flows through the plurality of second flat tubes, the plurality of fourth flat tubes, the plurality of third flat tubes, and the plurality of first flat tubes in this order, and when the outdoor heat exchanger acts as a condenser, the refrigerant flows through the plurality of first flat tubes, the plurality of third flat tubes, the plurality of fourth flat tubes, and the plurality of second flat tubes in this order.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of International Application No. PCT/JP2021/010336 filed on Mar. 15, 2021, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a heat exchanger and an air conditioner.

BACKGROUND

A conventional heat exchanger has a two-row structure that includes a group of windward flat tubes and a group of leeward flat tubes. PTL 1 discloses a heat exchanger that has a two-row structure and includes a group of windward flat tubes and a group of leeward flat tubes, wherein the flat tubes in each group are arranged in two layers in the vertical direction.

PATENT LITERATURE

• • PTL 1: Japanese Patent Laying-Open No. 2015-78830

As the refrigerant flows in the conventional heat exchanger, the flow rate of the refrigerant may decrease, which needs to be improved.

SUMMARY

It is an object of the present disclosure to provide a heat exchanger which has a two-row structure that allows refrigerant to flow suitably and is capable of functioning as both an evaporator and a condenser.

The heat exchanger of the present disclosure is a heat exchanger that exchanges heat between refrigerant and air. The heat exchanger includes: a group of windward flat tubes including a plurality of first flat tubes spaced apart from each other and a plurality of second flat tubes spaced apart from each other; a group of leeward flat tubes including a plurality of third flat tubes spaced apart from each other and a plurality of fourth flat tubes spaced apart from each other, the group of leeward flat tubes being disposed at a leeward position with respect to the group of windward flat tubes in a flow direction of air; and a distributor connected to ends of the plurality of third flat tubes and configured to distribute the refrigerant flowing in from a central position of the distributor to the plurality of third flat tubes through a plurality of branches when the heat exchanger acts as an evaporator. When the heat exchanger acts as an evaporator, the refrigerant flows through the plurality of second flat tubes, the plurality of fourth flat tubes, the plurality of third flat tubes, and the plurality of first flat tubes in this order, and when the heat exchanger acts as a condenser, the refrigerant flows through the plurality of first flat tubes, the plurality of third flat tubes, the plurality of fourth flat tubes, and the plurality of second flat tubes in this order.

According to the present disclosure, it is possible to provide a heat exchanger which has a two-row structure that allows refrigerant to flow suitably and is capable of functioning as both an evaporator and a condenser.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an air conditioner according to a first embodiment;

FIG. 2 is a diagram illustrating an outdoor heat exchanger in an evaporator flow according to the first embodiment;

FIG. 3 is an enlarged view illustrating a longitudinal connection tube;

FIG. 4 is an enlarged view illustrating a U-shape bend tube;

FIG. 5 is an exploded perspective view illustrating a distributor according to the first embodiment;

FIG. 6 is a diagram illustrating a distributor in a condenser flow according to the first embodiment;

FIG. 7 is a side view illustrating an outdoor heat exchanger in the evaporator flow according to the first embodiment;

FIG. 8 is a diagram illustrating the outdoor heat exchanger in a condenser flow according to the first embodiment;

FIG. 9 is a side view illustrating the outdoor heat exchanger in the condenser flow according to the first embodiment;

FIG. 10 is a diagram illustrating an outdoor heat exchanger in an evaporator flow according to a second embodiment;

FIG. 11 is an exploded perspective view illustrating a distributor according to a second embodiment;

FIG. 12 is a diagram illustrating a distributor in a condenser flow according to the second embodiment;

FIG. 13 is a side view illustrating an outdoor heat exchanger in an evaporator flow according to the second embodiment.

FIG. 14 is a diagram illustrating the outdoor heat exchanger in the condenser flow according to the second embodiment;

FIG. 15 is a side view illustrating the outdoor heat exchanger in the condenser flow according to the second embodiment.

FIG. 16 is an exploded perspective view illustrating a plate laminate according to the second embodiment;

FIG. 17 is a side view illustrating a plate laminate according to the second embodiment;

FIG. 18 is an exploded perspective view illustrating a plate laminate according to a modification;

FIG. 19 is a side view illustrating the plate laminate according to the modification; and

FIG. 20 is a diagram illustrating the shape of fins according to a third embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments to be described below, when a reference is made to a number, an amount or the like, the scope of the present disclosure is not necessarily limited to the number, the amount or the like unless otherwise specified. The same or equivalent components are denoted by the same reference numerals, and the description thereof may not be repeated. It is intended from the beginning that the embodiments may be combined appropriately.

First Embodiment

FIG. 1 is a diagram illustrating an air conditioner 100 according to a first embodiment. FIG. 1 illustrates the functional connection and arrangement of each unit in the air conditioner 100, and does not necessarily define the physical connection and arrangement of each unit. Hereinafter, the description will be carried out by assuming that the heat exchanger according to the first embodiment is used in the air conditioner 100, but the present disclosure is not limited thereto. For example, the heat exchanger may be used in a refrigeration cycle apparatus with a refrigerant circulation circuit. Although the air conditioner 100 is described as being capable to switch between a cooling operation and a heating operation, the air conditioner 100 is not limited thereto, and may be configured to perform only the cooling operation or the heating operation.

<Configuration of Air Conditioner>

The air conditioner 100 according to the first embodiment will be described in detail. As illustrated in FIG. 1, the air conditioner 100 includes a compressor 41, a four-way valve 42, an outdoor heat exchanger (heat exchanger on heat source side) 1, a throttle device 44, an indoor heat exchanger (heat exchanger on load side) 45, an outdoor fan (fan on heat source side) 46, an indoor fan (fan on load side) 47, and a controller 48. The air conditioner 100 is constructed by an indoor unit 100A that includes the indoor heat exchanger 45 and an outdoor unit 100B that includes the outdoor heat exchanger 1, which are connected by an extension tube 49. In the air conditioner 100, the compressor 41, the four-way valve 42, the outdoor heat exchanger 1, the throttle device 44, and the indoor heat exchanger 45 are connected by refrigerant tubes to form a refrigerant circulation circuit. In FIG. 1, the flow of refrigerant during the cooling operation is indicated by dotted arrows, and the flow of refrigerant during the heating operation is indicated by solid arrows.

The compressor 41, the four-way valve 42, the throttle device 44, the outdoor fan 46, the indoor fan 47, various sensors and the like are connected to the controller 48. The controller 48 switches the flow path of the four-way valve 42 so as to switch the cooling operation and the heating operation.

The flow of the refrigerant during the cooling operation will be described. The high-pressure high-temperature gas refrigerant discharged from the compressor 41 flows into the outdoor heat exchanger 1 through the four-way valve 42, and is condensed by exchanging heat with air supplied by the outdoor fan 46. The condensed refrigerant becomes a high-pressure liquid refrigerant, flows out from the outdoor heat exchanger 1, and is converted into a low-pressure gas-liquid two-phase refrigerant by the throttle device 44. The low-pressure gas-liquid two-phase refrigerant flows into the indoor heat exchanger 45 and is evaporated by exchanging heat with the air supplied by the indoor fan 47, thereby cooling the room. The evaporated refrigerant becomes a low-pressure gas refrigerant, flows out from the indoor heat exchanger 45, and is sucked into the compressor 41 through the four-way valve 42.

The flow of the refrigerant during the heating operation will be described. The high-pressure high-temperature gas refrigerant discharged from the compressor 41 flows into the indoor heat exchanger 45 through the four-way valve 42, and is condensed by exchanging heat with air supplied by the indoor fan 47, thereby heating the room. The condensed refrigerant becomes a high-pressure liquid refrigerant, flows out from the indoor heat exchanger 45, and is converted into a low-pressure gas-liquid two-phase refrigerant by the throttle device 44. The low-pressure gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 1, and is evaporated by exchanging heat with the air supplied by the outdoor fan 46. The evaporated refrigerant becomes a low-pressure gas refrigerant, flows out from the outdoor heat exchanger 1, and is sucked into the compressor 41 through the four-way valve 42.

<Configuration of Outdoor Heat Exchanger 1>

The outdoor heat exchanger 1 according to the first embodiment will be described. FIG. 2 is a diagram illustrating the outdoor heat exchanger 1 in an evaporator flow according to the first embodiment, FIG. 3 is an enlarged view illustrating a longitudinal connection tube 18, FIG. 4 is an enlarged view illustrating a U-shape bend tube 19, FIG. 5 is an exploded perspective view illustrating the distributor 10 according to the first embodiment, FIG. 6 is a diagram illustrating the distributor 10 in a condenser flow according to the first embodiment, and FIG. 7 is a side view illustrating the outdoor heat exchanger 1 in the evaporator flow according to the first embodiment.

As illustrated in FIG. 2, the outdoor heat exchanger 1 is an air heat exchanger having a two-row structure. The outdoor heat exchanger 1 includes a windward heat exchanger 1A and a leeward heat exchanger 1B. The windward heat exchanger 1A is formed as a group of windward flat tubes that includes a plurality of flat tubes 20 disposed at a windward position in a flow direction of wind W and spaced apart from each other, and the leeward heat exchanger 1B is formed as a group of leeward flat tubes that includes a plurality of flat tubes 30 disposed at a leeward position in the flow direction of wind W and spaced apart from each other. Although the air heat exchanger 1A and the air heat exchanger 1B are disposed close to each other in the flow direction of wind (air) W, they are illustrated as being spaced apart from each other in the drawing. In the following description, the number of the plurality of flat tubes 20 and the number of the plurality of flat tubes 30 are given as an example, and the number of the flat tubes can be modified appropriately. For the purpose of heat exchange, each flat tube is provided with a plurality of fins (not shown) spaced apart from each other at equal intervals.

The windward heat exchanger 1A, which is formed as a group of windward flat tubes, is divided into an upper section and a lower section. The windward heat exchanger 1A includes a windward main heat exchanger 11 constituted by the upper section and a windward sub heat exchanger 12 constituted by the lower section. The windward main heat exchanger 11 includes a plurality of first flat tubes 201 spaced apart from each other. The windward sub heat exchanger 12 includes a plurality of second flat tubes 202 spaced apart from each other. The number of the first flat tubes 201 is greater than the number of the second flat tubes 202. In the windward heat exchanger 1A, the plurality of first flat tubes 201 are disposed above the plurality of second flat tubes 202.

The windward heat exchanger 1A includes a first header tube 15 and a second header tube 16. A first connection tube 15a, through which refrigerant flows in and out, is provided at an upper position of the first header tube 15. A second connection tube 16a, through which refrigerant flows in and out, is provided at a lower position of the second header tube 16. The first header tube 15 and the windward main heat exchanger 11 are connected to first connection portions 20a of the plurality of first flat tubes 201. The second header tube 16 and the windward sub heat exchanger 12 are connected to the first connection portions 20a of the plurality of second flat tubes 202. The windward heat exchanger 1A and the leeward heat exchanger 1B are connected to each other at second connection portions 20b of the plurality of flat tubes 20 via a U-shape bend tube 19 illustrated in FIG. 4. One ends of the plurality of first flat tubes 201 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction via third connection portions 20c, each of which is bent in a U-shape, and one ends of the plurality of second flat tubes 202 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction via the third connection portions 20c.

The leeward heat exchanger 1B, which is formed as a group of leeward flat tubes, is divided into an upper section and a lower section. The leeward heat exchanger 1B includes a leeward main heat exchanger 13 constituted by the upper section and a leeward sub heat exchanger 14 constituted by the lower section. The leeward main heat exchanger 13 includes a plurality of third flat tubes 301 spaced apart from each other. The leeward sub heat exchanger 14 includes a plurality of fourth flat tubes 302 spaced apart from each other. The number of the third flat tubes 301 is greater than the number of the fourth flat tubes 302. In the leeward heat exchanger 1B, the plurality of third flat tubes 301 are disposed above the plurality of fourth flat tubes 302.

The leeward heat exchanger 1B includes a distributor 10, a third header tube 17, and a longitudinal connection tube 18 illustrated in FIG. 3. The distributor 10 includes an upper first distributor 10a, a central second distributor 10b, and a lower third distributor 10c. The inside of the third header tube 17 is partitioned into a lower first space 17a, a central second space 17b, and an upper third space 17c. The longitudinal connection tube 18 includes a first longitudinal connection tube 18a that connects the first distributor 10a and the first space 17a to each other, a second longitudinal connection tube 18b that connects the second distributor 10b and the second space 17b to each other, and a third longitudinal connection tube 18c that connects the third distributor 10c and the third space 17c to each other.

The first distributor 10a and the leeward main heat exchanger 13 are connected to fourth connection portions 30a of the third flat tubes 301. The second distributor 10b and the leeward main heat exchanger 13 are connected to the fourth connection portions 30a of the third flat tubes 301. The third distributor 10c and the leeward main heat exchanger 13 are connected to the fourth connection portions 30a of the plurality of third flat tubes 301.

The first space 17a and the leeward sub heat exchanger 14 are connected to the fourth connection portions 30a of the plurality of fourth flat tubes 302. The second space 17b and the leeward sub heat exchanger 14 are connected to the fourth connection portions 30a of the plurality of fourth flat tubes 302. The third space 17c and the leeward sub heat exchanger 14 are connected to fifth connection portions 30b of the fourth flat tubes 302.

The windward heat exchanger 1A and the leeward heat exchanger 1B are connected to each other at the fifth connection portions 30b of the plurality of flat tubes 30 via the U-shape bend tube 19 illustrated in FIG. 4. One ends of the plurality of third flat tubes 301 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction via sixth connection portions 30c, each of which is bent in a U-shape, and one ends of the plurality of fourth flat tubes 302 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction via the sixth connection portions 30c.

The other ends of the plurality of first flat tubes 201 (in the windward heat exchanger 1A which is formed as a group of windward flat tubes) opposite to the ends that are connected to each other in pairs in the vertical direction by the third connection portions 20c and the other ends of the plurality of third flat tubes 301 (in the leeward heat exchanger 1B which is formed as a group of leeward flat tubes) opposite to the ends that are connected to each other in pairs in the vertical direction by the sixth connection portions 30c are connected to each other alternately. The other ends of the plurality of second flat tubes 202 (in the windward heat exchanger 1A which is formed as a group of windward flat tubes) opposite to the ends that are connected to each other in pairs in the vertical direction by the third connection portions 20c and the other ends of the plurality of fourth flat tubes 302 (in the leeward heat exchanger 1B which is formed as a group of leeward flat tubes) opposite to the ends that are connected to each other in pairs in the vertical direction by the sixth connection portions 30c are connected to each other alternately.

<Evaporator Flow>

Hereinafter, the flow of the refrigerant when the outdoor heat exchanger 1 according to the first embodiment functions as an evaporator will be described. During the heating operation of the air conditioner 100, the outdoor heat exchanger 1 functions as an evaporator. Arrows indicated by broken lines in FIG. 2 indicate the flow direction of the refrigerant. The refrigerant flows in order from a flow path F1 to a flow path F13. In the case of the evaporator flow, the gas-liquid two-phase refrigerant flows through the flow path F1 formed by the second connection tube 16a of the windward heat exchanger 1A into the second header tube 16. The refrigerant flown through the flow path F1 flows through the three first connection portions 20a extending from the second header tube 16 and a flow path F2 formed by the flat tube 20, and is circulated back at the third connection portion 20c. Each refrigerant circulated back at the third connection portion 20c flows through a flow path F3 formed by the flat tube 20 into a flow path F4 formed by the U-shape bend tube 19 via the second connection portion 20b.

Thereafter, the refrigerant flows through the three fifth connection portions 30b of the leeward heat exchanger 1B, and then flows through a flow path F5 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. Thereafter, the refrigerant flows through a flow path F6 formed by the flat tube 30 into the first space 17a, the second space 17b, and the third space 17c of the third header tube 17. The refrigerant flown into the first space 17a flows through a flow path F7 formed by the first longitudinal connection tube 18a into the first distributor 10a. The refrigerant flown into the second space 17b flows through the flow path F7 formed by the second longitudinal connection tube 18b into the second distributor 10b. The refrigerant flown into the third space 17c flows through the flow path F7 formed by the third longitudinal connection tube 18c into the third distributor 10c.

The refrigerant flown into the first distributor 10a flows through the four fourth connection portions 30a of the leeward heat exchanger 1B after multiple branches, and then flows through a flow path F8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. The refrigerant flown into the second distributor 10b flows through the four fourth connection portions 30a of the leeward heat exchanger 1B after multiple branches, and then flows through the flow path F8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. The refrigerant flown into the third distributor 10c flows through the four fourth connection portions 30a of the leeward heat exchanger 1B after multiple branches, and then flows through the flow path F8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c.

Each refrigerant circulated back at the sixth connection portion 30c flows through a flow path F9 formed by the flat tube 30 into the fifth connection portion 30b, and then flows through a flow path F10 formed by the U-shape bend tube 19. Thereafter, the refrigerant flows through the twelve second connection portions 20b of the windward heat exchanger 1A, and then flows through a flow path F11 formed by the flat tube 20, and is circulated back at the third connection portion 20c. Each refrigerant circulated back at the third connection portion 20c flows through a flow path F12 formed by the flat tube 20 into the first header tube 15. The refrigerant flown into the first header tube 15 is converted into a gas refrigerant by exchanging heat with the outdoor air when flowing from the flow path F1 to the flow path F12. The gas refrigerant flows through a flow path F13 formed by the first connection tube 15a of the windward heat exchanger 1A and flows out of the outdoor heat exchanger 1. Due to a temperature difference between the air and the refrigerant when heat is exchanged between the wind (the air) W and the refrigerant, frost FR is formed on the surface of the windward main heat exchanger 11.

<Longitudinal Connection Tube 18>

As illustrated in FIG. 3, the longitudinal connection tube 18 is composed of three thin round tubes. The first space 17a of the third header tube 17 and the first distributor 10a of the distributor 10 are connected to each other by a first longitudinal connection tube 18a. The second space 17b of the third header tube 17 and the second distributor 10b of the distributor 10 are connected to each other by a second longitudinal connection tube 18b. The third space 17c of the third header tube 17 and the third distributor 10c of the distributor are connected to each other by a third longitudinal connection tube 18c.

<U-Shape Bend Tube 19>

A U-shape bend tube 19 located at the uppermost position among the plurality of U-shape bend tubes 19 will be described. As illustrated in FIG. 4, the second connection portion 20b of the upper main heat exchanger 11 and the fifth connection portion 30b of the lower main heat exchanger 13 are connected to each other via a circular U-shape bend tube 19. The U-shape bend tube 19 and the second connection portion 20b are joined to each other at the first end 19a by brazing. The U-shape bend tube 19 and the fifth connection portion 30b are joined to each other at the second end 19b by brazing.

<Distributor 10>

Hereinafter, the flow of the refrigerant in the distributor 10 of the outdoor heat exchanger 1 according to the first embodiment will be described. The first distributor 10a, the second distributor 10b and the third distributor 10c in the distributor 10 have the same configuration. When the outdoor heat exchanger 1 functions as an evaporator, the refrigerant flowing through the refrigerant tube flows into the distributor 10 through a refrigerant inflow unit 160A and is distributed by the distributor 10, the refrigerant flows out from a plurality of refrigerant outflow units 160B into the fourth connection portions 30a formed by the four flat tubes 30. When the outdoor heat exchanger 1 functions as a condenser, the refrigerant flows in a direction opposite to the flow direction mentioned above.

The configuration of the distributor 10 will be described in detail. As illustrated in FIG. 5, the distributor 10 includes a first plate member 110, a second plate member 120, a third plate member 130, a fourth plate member 140, and a fifth plate member 150. The first plate member 110, the second plate member 120, the third plate member 130, the fourth plate member 140 and the fifth plate member 150 are laminated and joined together by brazing. Each of the first plate member 110, the second plate member 120, the third plate member 130, the fourth plate member 140, and the fifth plate member 150 has a thickness of, for example, about 1 to 10 mm, and is made of aluminum.

The first plate member 110 includes a plurality of convex portions 110A and 110B, each of which protrudes forward from a main body 111. The first plate member 110 includes an inflow tube 160C protruding forward and a refrigerant inflow unit 160A connected to the inflow tube 160C. The second plate member 120 is provided with a plurality of circular holes 120A, 120B and 120C. The third plate member 130 is provided with long holes 130A extending in the left-right direction and S-shaped holes 130B. The fourth plate member 140 is provided with long holes 140A and 140B extending in the left-right direction. The fifth plate member 150 is provided with a plurality of through holes extending in the left-right direction which serve as the plurality of refrigerant outflow units 160B.

Each plate member is processed by press working or cutting. The first plate member 110 is processed, for example, by press working. Each of the second plate member 120, the third plate member 130, the fourth plate member 140, and the fifth plate member 150 is processed, for example, by cutting.

The distributor 10 is disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 1 is horizontal. The distributor 10 may be disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 1 is vertical. The distributor 10 may be disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 1 is oblique.

In FIG. 5, a part of the flow of the refrigerant is indicated by arrows. The direction of each arrow indicates the flow direction of the refrigerant. Hereinafter, a part of the flow of the refrigerant will be described. The refrigerant that has flown through the inflow tube 160C flows from the refrigerant inflow unit 160A into the hole 120A of the second plate member 120, collides with the surface of the fourth plate member 140, and thereby is branched in the left-right direction along the hole 130A of the third plate member 130. The branched refrigerant flows through the hole 120B of the second plate member 120 from the rear direction toward the front direction, and collides with the convex portion 110A and the convex portion 110B of the first plate member 110.

Among the refrigerant that collides with the convex portions, the refrigerant that collides with the convex portion 110B of the first plate member 110 flows obliquely downward along the convex portion 110B. The refrigerant flowing obliquely downward flows through the hole 120C of the second plate member 120, collides with the surface of the fourth plate member 140, and thereby is branched into the upper side and the lower side of the S shape along the hole 130B of the third plate member 130. The refrigerant in the upper side of the S-shape flows through the hole 140A of the fourth plate member 140, and then flows through the refrigerant outflow unit 160B of the fifth plate member 150 into the fourth connection portion 30a. The refrigerant in the lower side of the S-shape flows through the hole 140B of the fourth plate member 140, and then flows through the refrigerant outflow unit 160B of the fifth plate member 150 into the fourth connection portion 30a. Thus, the distributor 10 can equalize the flow rate of the refrigerant without lowering the flow rate by branching the refrigerant to flow forward and backward repeatedly.

In FIG. 6, a part of the flow of the refrigerant is indicated by arrows. As illustrated in FIG. 6, when the distributor 10 functions as a condenser, the refrigerant flowing in from the fourth connection portions 30a is merged in a second communication space 170B located at an upper position and a second communication space 170B located at a lower position. The merged refrigerant is further merged in a first communication space 170A, and flows out from the inflow tube 160C.

The outdoor heat exchanger 1 in the evaporator flow according to the first embodiment will be described with reference to a side view of FIG. 7. In FIG. 7, a pipe on the front side is indicated by a solid line, and a pipe on the back side is indicated by a broken line. As illustrated in FIG. 7, when the outdoor heat exchanger 1 in the evaporator flow is viewed from the side surface, the refrigerant distributed by the distributor 10 flows through the fourth connection portion 30a of the leeward main heat exchanger 13. The refrigerant flown through the fourth connection portion 30a flows in a direction from the front side to the back side, and then flows upward through the sixth connection portion 30c.

Thereafter, the refrigerant flows in a direction from the back side to the front side, and then flows through the fifth connection portion 30b. The refrigerant flown through the fifth connection portion 30b flows through the U-shape bend tube 19, and then flows through the second connection portion 20b of the windward heat exchanger 11. Thereafter, the refrigerant flows in a direction from the front side to the back side, and then flows downward through the third connection portion 20c. Thereafter, the refrigerant flows in a direction from the back side to the front side, and then flows through the first connection portion 20a into the first header tube 15. Due to a temperature difference between the air and the refrigerant when heat is exchanged between the wind (the air) W and the refrigerant, frost FR is formed on the surface of the windward main heat exchanger 11.

<Condenser Flow>

Hereinafter, the flow of the refrigerant when the outdoor heat exchanger 1 according to the first embodiment functions as a condenser will be described. During the cooling operation of the air conditioner 100, the outdoor heat exchanger 1 functions as a condenser. Arrows indicated by broken lines in FIG. 8 indicate the flow direction of the refrigerant. The refrigerant flows in order from a flow path G1 to a flow path G13. In the case of the condenser flow, the high-temperature high-pressure gas refrigerant flows through the flow path G1 formed by the first connection tube 15a of the windward heat exchanger 1A into the first header tube 15. The refrigerant flown through the flow path G1 flows through the twelve first connection portions 20a extending from the first header tube 15 and a flow path G2 formed by the flat tube 20, and is circulated back at the third connection portion 20c. Each refrigerant circulated back at the third connection portion 20c flows through a flow path G3 formed by the flat tube 20 into a flow path G4 formed by the U-shape bend tube 19 via the second connection portion 20b.

Thereafter, the refrigerant flows through the twelve fifth connection portions 30b of the leeward heat exchanger 1B, and then flows through a flow path G5 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. Thereafter, the refrigerant flows through a flow path G6 formed by the flat tube 30 into the first distributor 10a, the second distributor 10b, and the third distributor 10c. The refrigerant flown into and merged in the first distributor 10a flows through a flow path G7 formed by the first longitudinal connection tube 18a into the first space 17a. The refrigerant flown into and merged in the second distributor 10b flows through the flow path G7 formed by the second longitudinal connection tube 18b into the second space 17b. The refrigerant flown into and merged in the third distributor 10c flows through the flow path G7 formed by the third longitudinal connection tube 18c into the third space 17c.

The refrigerant flown into the first space 17a flows through the fourth connection portion 30a of the leeward heat exchanger 1B, and then flows through a flow path G8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. The refrigerant flown into the second space 17b flows through the fourth connection portion 30a of the leeward heat exchanger 1B, and then flows through the flow path G8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c. The refrigerant flown into the third space 17c flows through the fourth connection portion 30a of the leeward heat exchanger 1B, and then flows through the flow path G8 formed by the flat tube 30, and is circulated back at the sixth connection portion 30c.

Each refrigerant circulated back at the sixth connection portion 30c flows through a flow path G9 formed by the flat tube 30 into the fifth connection portion 30b, and then flows through a flow path G10 formed by the U-shape bend tube 19. Thereafter, the refrigerant flows through the three second connection portions 20b of the windward heat exchanger 1A, and then flows through a flow path G11 formed by the flat tube 20, and is circulated back at the third connection portion 20c. Each refrigerant circulated back at the third connection portion 20c flows through a flow path G12 formed by the flat tube 20 into the second header tube 16. The refrigerant flown into the second header tube 16 is converted into a gas refrigerant by exchanging heat with the outdoor air when flowing from the flow path G1 to the flow path G12. The gas refrigerant flows through a flow path G13 formed by the second connection tube 16a of the windward heat exchanger 1A and flows out of the outdoor heat exchanger 1.

When the outdoor heat exchanger 1 functions as a condenser, the high-temperature high-pressure gas refrigerant firstly flows through the windward main heat exchanger 11, which makes it possible to effectively defrost the frost FR formed on the surface of the windward main heat exchanger 11.

The outdoor heat exchanger 1 in a condenser flow according to the first embodiment will be described with reference to a side view of FIG. 9. In FIG. 9, a pipe on the front side is indicated by a solid line, and a pipe on the back side is indicated by a broken line. As illustrated in FIG. 9, when the outdoor heat exchanger 1 in the condenser flow is viewed from the side surface, the refrigerant flown in from the first header tube 15 flows through the first connection portion 20a of the windward main heat exchanger 11. The refrigerant flown through the first connection portion 20a flows in a direction from the front side to the back side, and then flows upward through the third connection portion 20c.

Thereafter, the refrigerant flows in a direction from the back side to the front side, and then flows through the second connection portion 20b. The refrigerant flown through the second connection portion 20b flows through the U-shape bend tube 19, and then flows through the fifth connection portion 30b of the leeward main heat exchanger 13. Thereafter, the refrigerant flows in a direction from the front side to the back side, and then flows downward through the sixth connection portion 30c. Thereafter, the refrigerant flows in a direction from the back side to the front side, and then flows through the fourth connection portion 30a into the distributor 10. The frost FR on the surface of the windward main heat exchanger 11 may be effectively defrosted by the high-temperature and high-pressure gas refrigerant flowing the windward main heat exchanger 11.

Second Embodiment

<Configuration of Outdoor Heat Exchanger 2>

The outdoor heat exchanger 2 according to a second embodiment will be described. FIG. 10 is a view illustrating the outdoor heat exchanger 2 in an evaporator flow according to the second embodiment, FIG. 11 is an exploded perspective view illustrating the distributor 50 according to the second embodiment, FIG. 12 is a view illustrating the distributor 50 in a condenser flow according to the second embodiment, and FIG. 13 is side view illustrating the outdoor heat exchanger 1 in an evaporator flow according to the second embodiment.

The outdoor heat exchanger 2 according to the second embodiment is different from the outdoor heat exchanger 1 according to the first embodiment in the shape of a connection portion between the first header tube 15 and the windward heat exchanger 1A, the shape of the distributor 50, the shape of a connection portion between the distributor 50 and the leeward heat exchanger 1B, and the shape of a connection portion between the windward heat exchanger 1A and the leeward heat exchanger 1B. In the following, the description will be carried out mainly on the differences between the outdoor heat exchanger 2 and the outdoor heat exchanger 1.

As illustrated in FIG. 10, the outdoor heat exchanger 2 is an air heat exchanger having a two-row structure. The outdoor heat exchanger 2 includes a windward heat exchanger 2A and a leeward heat exchanger 2B. The windward heat exchanger 2A is formed as a group of windward flat tubes that includes a plurality of flat tubes 20 disposed at a windward position in a flow direction of wind W and spaced apart from each other, and the leeward heat exchanger 2B is formed as a group of leeward flat tubes that includes a plurality of flat tubes 30 disposed at a leeward position in the flow direction of the wind W and spaced apart from each other. Although the air heat exchanger 2A and the air heat exchanger 2B are illustrated as being spaced apart from each other in the drawing, they are disposed close to each other in the flow direction of the wind (the air) W. In the following description, the number of the plurality of flat tubes 20 and the number of the plurality of flat tubes 30 are given as an example, and the number of the flat tubes can be modified appropriately.

The windward heat exchanger 2A, which is formed as a group of windward flat tubes, is divided into an upper section and a lower section. The windward heat exchanger 2A includes a windward main heat exchanger 11 constituted by the upper section and a windward sub heat exchanger 12 constituted by the lower section. The windward main heat exchanger 11 includes a plurality of first flat tubes 201 spaced apart from each other. The windward sub heat exchanger 12 includes a plurality of second flat tubes 202 spaced apart from each other. The number of the first flat tubes 201 is greater than the number of the second flat tubes 202. In the windward heat exchanger 2A, the plurality of first flat tubes 201 are disposed above the plurality of second flat tubes 202.

The windward heat exchanger 2A includes a first header tube 15 and a second header tube 16. A first connection tube 15a, through which refrigerant flows in and out, is provided at an upper position of the first header tube 15. A second connection tube 16a, through which refrigerant flows in and out, is provided at a lower position of the second header tube 16. The first header tube 15 and the windward main heat exchanger 11 are connected to the first connection portions 20a of the plurality of first flat tubes 201. The second header tube 16 and the windward sub heat exchanger 12 are connected to the first connection portions 20a of the plurality of second flat tubes 202.

The leeward heat exchanger 2B, which is formed as a group of leeward flat tubes, is divided into an upper section and a lower section. The leeward heat exchanger 2B includes a leeward main heat exchanger 13 constituted by the upper section and a leeward sub heat exchanger 14 constituted by the lower section. The leeward main heat exchanger 13 includes a plurality of third flat tubes 301 spaced apart from each other. The leeward sub heat exchanger 14 includes a plurality of fourth flat tubes 302 spaced apart from each other. The number of the third flat tubes 301 is greater than the number of the fourth flat tubes 302. In the leeward heat exchanger 2B, the plurality of third flat tubes 301 are disposed above the plurality of fourth flat tubes 302.

The leeward heat exchanger 2B includes a distributor 50, a third header tube 17, and a longitudinal connection tube 18. The distributor 50 includes an upper first distributor 50a, a central second distributor 50b, and a lower third distributor 50c. The inside of the third header tube 17 is partitioned into a lower first space 17a, a central second space 17b, and an upper third space 17c. The longitudinal connection tube 18 includes a first longitudinal connection tube 18a that connects the first distributor 50a and the first space 17a to each other, a second longitudinal connection tube 18b that connects the second distributor 50b and the second space 17b to each other, and a third longitudinal connection tube 18c that connects the third distributor 50c and the third space 17c to each other.

The first distributor 50a and the leeward main heat exchanger 13 are connected to the fourth connection portion 30a of the third flat tubes 301. The second distributor 50b and the leeward main heat exchanger 13 are connected to the fourth connection portion 30a of the third flat tubes 301. The third distributor 50c and the leeward main heat exchanger 13 are connected to the fourth connection portion 30a of the plurality of third flat tubes 301. The first space 17a and the leeward sub heat exchanger 14 are connected to the fourth connection portions 30a of the plurality of fourth flat tubes 302. The second space 17b and the leeward sub heat exchanger 14 are connected to the fourth connection portions 30a of the plurality of fourth flat tubes 302. The third space 17c and the leeward sub heat exchanger 14 are connected to the fifth connection portions 30b of the fourth flat tubes 302.

One end of each flat tube 20 in the windward heat exchanger 2A (which is a group of windward flat tubes) opposite to the other end where the refrigerant flows in and out is connected to one end of a corresponding flat tube 30 in the leeward heat exchanger 2B (which is a group of leeward flat tubes) opposite to the other end where the distributor 50 is connected. The flat tube 20 of the windward heat exchanger 2A and the flat tube 30 of the leeward heat exchanger 2B are connected to each other via a plate laminate 60.

<Evaporator Flow>

Hereinafter, the flow of the refrigerant when the outdoor heat exchanger 2 according to the second embodiment functions as an evaporator will be described. During the heating operation of the air conditioner 100, the outdoor heat exchanger 2 functions as an evaporator. Arrows indicated by broken lines in FIG. 10 indicate the flow direction of the refrigerant. The refrigerant flows in order from a flow path F1 to a flow path F9. In the case of the evaporator flow, the gas-liquid two-phase refrigerant flows through a flow path F1 formed by the second connection tube 16a of the windward heat exchanger 2A into the second header tube 16. The refrigerant flown through the flow path F1 flows through the six first connection portions 20a extending from the second header tube 16 into a flow path F2 formed by the flat tube 20. Thereafter, the refrigerant flows through a flow path F3 formed by the plate laminate 60.

The refrigerant flown through the flow path F3 flows through a flow path F4 formed by the flat tube 30 of the wind heat exchanger 2B into the first space 17a, the second space 17b, and the third space 17c of the third header tube 17. The refrigerant flown into the first space 17a flows through a flow path F5 formed by the first longitudinal connection tube 18a into the first distributor 50a. The refrigerant flown into the second space 17b flows through the flow path F5 formed by the second longitudinal connection tube 18b into the second distributor 50b. The refrigerant flown into the third space 17c flows through the flow path F5 formed by the third longitudinal connection tube 18c into the third distributor 50c.

The refrigerant flown into the first distributor 50a flows through the eight fourth connection portions 30a of the heat exchanger 2B after multiple branches, and then flows through a flow path F6 formed by the flat tube 30. The refrigerant flown into the second distributor 50b flows through the eight fourth connection portions 30a of the heat exchanger 2B after multiple branches, and then flows through the flow path F6 formed by the flat tube 30. The refrigerant flown into the third distributor 50c flows through the eight fourth connection portions 30a of the heat exchanger 2B after multiple branches, and then flows through the flow path F6 formed by the flat tube 30.

Thereafter, the refrigerant flows through a flow path F7 formed by the plate laminate 60. The refrigerant flown through the flow path F7 flows through a flow path F8 formed by the flat tube 20 of the windward heat exchanger 2A into the first header tube 15. The refrigerant flown into the first header tube 15 is converted into a gas refrigerant by exchanging heat with the outdoor air when flowing from the flow path F1 to the flow path F8. The gas refrigerant flows through a flow path F9 formed by the first connection tube 15a of the windward heat exchanger 2A and flows out of the outdoor heat exchanger 2. Due to a temperature difference between the air and the refrigerant when heat is exchanged between the wind (the air) W and the refrigerant, frost FR is formed on the surface of the windward main heat exchanger 11.

<Distributor 50>

Hereinafter, the flow of the refrigerant in the distributor 50 of the outdoor heat exchanger 2 according to the second embodiment will be described. The first distributor 50a, the second distributor 50b and the third distributor 50c in the distributor 50 have the same configuration. When the outdoor heat exchanger 2 functions as an evaporator, the refrigerant flowing through the refrigerant tube flows into the distributor 50 through a refrigerant inflow unit 260A and is distributed by the distributor 50, the refrigerant flows out from a plurality of refrigerant outflow units 260B into the fourth connection portions 30a formed by the eight flat tubes 30. When the outdoor heat exchanger 2 functions as a condenser, the refrigerant flows in a direction opposite to the flow mentioned above.

The configuration of the distributor 50 will be described in detail. As illustrated in FIG. 11, the distributor 50 includes a first plate member 210, a second plate member 220, a third plate member 230, a fourth plate member 240, and a fifth plate member 250. The first plate member 210, the second plate member 220, the third plate member 230, the fourth plate member 240 and the fifth plate member 250 are laminated and joined together by brazing. Each of the first plate member 210, the second plate member 220, the third plate member 230, the fourth plate member 240, and the fifth plate member 250 has a thickness of, for example, about 1 to 10 mm, and is made of aluminum.

The first plate member 210 includes a plurality of convex portions 210A, 210B, 210C, 210D, 210E and 210F, each of which protrudes forward from the main body 211. The first plate member 210 includes an inflow tube 260C protruding forward and a refrigerant inflow unit 260A connected to the inflow tube 260C. The second plate member 220 is provided with a plurality of circular holes 220A, 220B, 220C, 220D and 220E. The third plate member 230 is provided with long holes 230A and 230C extending in the left-right direction and S-shaped holes 230B and 230D. The fourth plate member 240 is provided with long holes 240A, 240B, 240C and 240D extending in the left-right direction. The fifth plate member 250 is provided with a plurality of through holes extending in the left-right direction which serve as the plurality of refrigerant outflow units 260B.

Each plate member is processed by press working or cutting. The first plate member 210 is processed, for example, by press working. Each of the second plate member 220, the third plate member 230, the fourth plate member 240, and the fifth plate member 250 is processed, for example, by cutting.

The distributor 50 is disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 2 is horizontal. The distributor 50 may be disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 2 is vertical. The distributor 50 may be disposed in such a manner that the flow direction of the refrigerant in each of the plurality of flat tubes 30 connected to the outdoor heat exchanger 2 is oblique.

In FIG. 11, a part of the flow of the refrigerant is indicated by arrows. The direction of each arrow indicates the flow direction of the refrigerant. Hereinafter, a part of the flow of the refrigerant will be described. The refrigerant that has flown through the inflow tube 260C flows from the refrigerant inflow unit 260A into the hole 220A of the second plate member 220, collides with the surface of the fourth plate member 240, and thereby is branched in the left-right direction along the hole 230A of the third plate member 230. The branched refrigerant flows through the hole 220B of the second plate member 220 from the rear direction toward the front direction, and collides with the convex portion 210A and the convex portion 210B of the first plate member 210.

Among the refrigerant that collides with the convex portions, the refrigerant that collides with the convex portion 210B of the first plate member 210 flows obliquely downward along the convex portion 210B. The refrigerant flowing obliquely downward flows through the hole 220C of the second plate member 220, collides with the surface of the fourth plate member 240, and thereby is branched in the left-right direction along the hole 230C of the third plate member 230. The branched refrigerant flows through the hole 220D of the second plate member 220 from the rear direction toward the front direction, and collides with the convex portion 210D and the convex portion 210F of the first plate member 210.

Among the refrigerant that collides with the convex portions, the refrigerant that collides with the convex portion 210F of the first plate member 210 flows obliquely downward along the convex portion 210F. The refrigerant flowing obliquely downward flows through the hole 220E of the second plate member 220, collides with the surface of the fourth plate member 240, and thereby is branched into the upper side and the lower side of the S shape along the hole 230D of the third plate member 230. The refrigerant in the upper side of the S-shape flows through the hole 240C of the fourth plate member 240, and then flows through the refrigerant outflow unit 260B of the fifth plate member 250 into the fourth connection portion 30a. The refrigerant in the lower side of the S-shape flows through the hole 240D of the fourth plate member 240, and then flows through the refrigerant outflow unit 260B of the fifth plate member 250 into the fourth connection portion 30a. Thus, the distributor 50 can equalize the flow rate of the refrigerant without lowering the flow rate by branching the refrigerant to flow forward and backward repeatedly.

In FIG. 12, a part of the flow of the refrigerant is indicated by arrows. As illustrated in FIG. 12, when the distributor 50 functions as a condenser, the refrigerant flowing in from the fourth connection portion 30a is merged in the four third communication spaces 270C. The merged refrigerant is further merged in the two second communication spaces 270B. The merged refrigerant is further merged in the first communication space 270A and flows out from the inflow tube 260C.

The outdoor heat exchanger 2 in the evaporator flow according to the second embodiment will be described with reference to a side view of FIG. 13. In FIG. 13, a pipe on the front side is indicated by a solid line, and a pipe on the back side is indicated by a broken line. As illustrated in FIG. 13, when the outdoor heat exchanger 2 of the evaporator flow is viewed from the side surface, the refrigerant distributed by the distributor 50 flows through the fourth connection portion 30a of the leeward main heat exchanger 13. The refrigerant flown through the fourth connection portion 30a flows in a direction from the front side to the back side, and then flows into the plate laminate 60.

Thereafter, the refrigerant flows in a direction from the back side to the front side, flows through the first connection portion 20a of the windward main heat exchanger 11, and flows into the first header tube 15. Due to a temperature difference between the air and the refrigerant when heat is exchanged between the wind (the air) W and the refrigerant, frost FR is formed on the surface of the windward main heat exchanger 11.

<Condenser Flow>

Hereinafter, the flow of refrigerant when the outdoor heat exchanger 2 according to the second embodiment functions as a condenser will be described. During the cooling operation of the air conditioner 100, the outdoor heat exchanger 2 functions as a condenser. Arrows indicated by broken lines in FIG. 14 indicate the flow direction of the refrigerant. The refrigerant flows in order from a flow path G1 to a flow path G9. In the case of the condenser flow, the high-temperature high-pressure gas refrigerant flows through the flow path G1 formed by the first connection tube 15a of the windward heat exchanger 2A into the first header tube 15. The refrigerant flown through the flow path G1 flows through the twenty-four first connection portions 20a extending from the first header tube 15 and flows through a flow path G2 formed by the flat tube 20. Thereafter, the refrigerant flows through a flow path G3 formed by the plate laminate 60.

The refrigerant flown through the flow path G3 flows through a flow path G4 formed by the flat tube 30 of the wind heat exchanger 2B into the first distributor 50a, the second distributor 50b, and the third distributor 50c. The refrigerant flown into and merged in the first distributor 50a flows through a flow path G5 formed by the first longitudinal connection tube 18a into the first space 17a. The refrigerant flown into and merged in the second distributor 50b flows through the flow path G5 formed by the second longitudinal connection tube 18b into the second space 17b. The refrigerant flown into and merged in the third distributor 50c flows through the flow path G5 formed by the third longitudinal connection tube 18c into the third space 17c.

The refrigerant flown into the first space 17a flows through the fourth connection portion 30a of the leeward heat exchanger 1B, and then flows through a flow path G6 formed by the flat tube 30. Thereafter, the refrigerant flows through a flow path G7 formed by the plate laminate 60. The refrigerant flown through the flow path G7 flows through a flow path G8 formed by the flat tube 20 of the windward heat exchanger 2A into the second header tube 16. The refrigerant flown into the second header tube 16 is converted into a liquid refrigerant exchanging heat with the outdoor air when flowing from the flow path G1 to the flow path G8. The liquid refrigerant flows through the flow path G9 formed by the second connection tube 16a of the windward heat exchanger 2A and flows out of the outdoor heat exchanger 2.

When the outdoor heat exchanger 2 functions as a condenser, the high-temperature high-pressure gas refrigerant firstly flows through the windward main heat exchanger 11, which makes it possible to effectively defrost the frost FR formed on the surface of the windward main heat exchanger 11.

The outdoor heat exchanger 2 in a condenser flow according to the second embodiment will be described with reference to a side view of FIG. 15. In FIG. 15, a pipe on the front side is indicated by a solid line, and a pipe on the back side is indicated by a broken line. As illustrated in FIG. 15, when the outdoor heat exchanger 2 in the condenser flow is viewed from the side surface, the refrigerant flowing in from the first header tube 15 flows through the first connection portion 20a of the windward main heat exchanger 11. The refrigerant flown through the first connection portion 20a flows in a direction from the front side to the back side, and then flows into the plate laminate 60.

Thereafter, the refrigerant flows in a direction from the back side to the front side, and then flows through the fourth connection portion 30a of the leeward main heat exchanger 13 into the distributor 50. The frost FR formed on the surface of the windward main heat exchanger 11 is effectively defrosted by the flow of the high-temperature and high-pressure gas refrigerant.

<Plate Laminate 60>

The configuration of the plate laminate 60 will be described. FIG. 16 is an exploded perspective view illustrating the plate laminate 60 according to the second embodiment. FIG. 17 is a side view illustrating the plate laminate 60 according to the second embodiment.

As illustrated in FIG. 16, the plate laminate 60 includes a first plate member 61, a second plate member 62, a third plate member 63, a fourth plate member 64, and a fifth plate member 65. The first plate member 61, the second plate member 62, the third plate member 63, the fourth plate member 64, and the fifth plate member 65 are laminated and joined together by brazing. As illustrated in FIG. 17, the first plate member 61, the third plate member 63 and the fifth plate member 65 are thicker than the second plate member 62 and the fourth plate member 64. Each plate member is made of aluminum, for example.

The first plate-shaped member 61 is provided with a plurality of first convex portions 61B on the left side and a plurality of second convex portions 61C on the right side, each of the convex portion being configured to project outward, in other words project toward the back side, from a main body 61A. The second plate member 62 is provided with a plurality of stepped holes 62A. The third plate member 63 is provided with a plurality of stepped holes 63A. The fourth plate member 64 is provided with a plurality of stepped holes 64A. The fifth plate member 65 is provided with a plurality of holes 65A displaced in the vertical direction on the left side and the right side. The first plate member 61 to the fifth plate member 65 of the plate laminate 60 form a flow path of the refrigerant.

A first end 20e of the plurality of flat tubes 20 constituting the group of windward flat tubes and a second end 30e of the plurality of flat tubes 30 constituting the group of leeward flat tubes are not coaxial to each other with respect to the flow direction of the refrigerant. As illustrated in FIG. 16, the refrigerant flown through the second end 30e flows from the plurality of second convex portions 61C into the plurality of first convex portions 61B, and then flows into the first end 20e.

Since the plate laminate 60 is provided with a convex-shaped channel, it is possible to increase the channel space and reduce the pressure loss as compared with a channel formed with the same number of parts and weight.

<Modification of Plate Laminate 60>

A modification of the plate laminate 60 will be described. FIG. 18 is an exploded perspective view illustrating a plate laminate 600 according to a modification. FIG. 19 is a side view illustrating the plate laminate 600 according to the modification.

As illustrated in FIG. 18, the plate laminate 600 includes a first plate member 610, a second plate member 620, a third plate member 630, a fourth plate member 640, and a fifth plate member 650. The first plate member 610, the second plate member 620, the third plate member 630, the fourth plate member 640, and the fifth plate member 650 are laminated and joined together by brazing. As illustrated in FIG. 19, the first plate member 610, the third plate member 630, and the fifth plate member 650 are thicker than the second plate member 620 and the fourth plate member 640. These plate members are made of aluminum, for example.

The first plate member 610 is provided with a plurality of third convex portions 610B protruding outward from the main body 610A. The second plate member 620 is provided with long holes 620A extending in the left-right direction. The third plate member 630 is provided with long holes 630A extending in the left-right direction. The fourth plate member 640 is provided with long holes 640A extending in the left-right direction. The fifth plate member 65 is provided with a plurality of paired long holes 650A coaxial to each other in the left-right direction. The first plate member 610 to the fifth plate member 650 of the plate laminate 600 form a flow path of the refrigerant.

The first end 20e of the plurality of flat tubes 20 constituting the group of windward flat tubes and the second end 30e of the plurality of flat tubes 30 constituting the group of leeward flat tubes are coaxial to each other with respect to the flow direction of the refrigerant. As illustrated in FIG. 18, the refrigerant flown through the second end 30e flows horizontally through the plurality of third convex portions 610B and then flows into the first end 20e.

Since the plate laminate 600 is provided with a convex-shaped channel, it is possible to increase the channel space and reduce the pressure loss as compared with a channel formed with the same number of parts and weight.

Third Embodiment

<Fin>

FIG. 20 is a diagram illustrating the shape of fins according to a third embodiment. In the third embodiment, the fins are applied to the outdoor heat exchanger 2 according to the second embodiment. A plurality of first fins 71 are arranged at equal intervals on the plurality of first flat tubes 201 in the windward main heat exchanger 11, and a plurality of second fins 72 are arranged at equal intervals on the plurality of third flat tubes 301 in the leeward main heat exchanger 13. The first fins 71 and the second fins 72 are made of aluminum.

In FIG. 20, the flow of the refrigerant in the evaporator flow during the heating operation is indicated by dotted arrows. The refrigerant flown into the longitudinal connection tube 18 flows through the distributor 50, the plurality of third flat tubes 301, the plate laminate 60, the plurality of first flat tubes 201, the first header tube 15, and the first connection tube 15a in this order. During the heat exchange between the refrigerant and the air (the wind W) in the evaporator flow, when the temperature of the refrigerant is equal to or lower than 0° C. (i.e., a dew point temperature of the air), a frost phenomenon occurs in which moisture in the air adheres to the evaporator and grows into frost. In the outdoor heat exchanger 2, the number of fins may be increased by narrowing the fin pitch so as to improve the heat exchange performance. However, in a situation where frost may be formed on the outdoor heat exchanger 2, if the fin pitch is made too narrow, the frost may be formed early on the windward main heat exchanger 11. The fins will be clogged by the frost, which deteriorates the heat exchange performance of the outdoor heat exchanger 2.

In the third embodiment, the fin pitch between the plurality of first fins 71 provided on the plurality of first flat tubes 201 of the windward main heat exchanger 11 is larger than the fin pitch between the plurality of second fins 72 provided on the plurality of third flat tubes 301 of the leeward main heat exchanger 13. As a result, it is possible to delay the time until the plurality of first fins 71 are clogged by the frost on the windward side where the frost is likely to occur while preventing the heat exchange performance of the outdoor heat exchanger 2 from being deteriorated in the evaporator flow.

In the third embodiment, in the condenser flow during the cooling operation, the refrigerant flowing through the plurality of first flat tubes 201 of the windward main heat exchanger 11 is high-temperature high-pressure gas refrigerant. In the outdoor heat exchanger 2, since the fin pitch between the plurality of first fins 71 is wider, it is possible to easily defrost the frost in the condenser flow and discharge the generated water to a lower portion of the outdoor heat exchanger 2. Thus, it is possible to shorten the defrosting time and improve the heat exchange performance of the outdoor heat exchanger 2.

Although in the third embodiment it is described that the fins are applied to the outdoor heat exchanger 2 according to the second embodiment, the fins may be applied to the outdoor heat exchanger 1 according to the first embodiment. The plurality of first fins 71 provided on the plurality of first flat tubes 201 of the windward main heat exchanger 11 may be similarly provided on the plurality of second flat tubes 202 of the windward sub heat exchanger 12. The plurality of second fins 72 provided on the plurality of third flat tubes 301 of the leeward main heat exchanger 13 may be similarly provided on the plurality of fourth flat tubes 302 of the leeward sub heat exchanger 14. The fin pitch between the plurality of first fins 71 provided on the plurality of first flat tubes 201 and the plurality of second flat tubes 202 may be larger than the fin pitch between the plurality of second fins 72 provided on the plurality of third flat tubes 301 and the plurality of fourth flat tubes 302.

<Summary>

The present disclosure relates to an outdoor heat exchanger 1 (2) that exchanges heat between refrigerant and air. The outdoor heat exchanger 1 (2) includes: a group of windward flat tubes including a plurality of first flat tubes 201 spaced apart from each other and a plurality of second flat tubes 202 spaced apart from each other; a group of leeward flat tubes including a plurality of third flat tubes 301 spaced apart from each other and a plurality of fourth flat tubes 302 spaced apart from each other, the group of leeward flat tubes being disposed at a leeward position with respect to the group of windward flat tubes in a flow direction of air; and a distributor 10 (50) connected to ends of the plurality of third flat tubes 301 and configured to distribute the refrigerant flowing in from a central position of the distributor to the plurality of third flat tubes 301 through a plurality of branches when the heat exchanger acts as an evaporator. When the outdoor heat exchanger 1 (2) acts as an evaporator, the refrigerant flows through the plurality of second flat tubes 202, the plurality of fourth flat tubes 302, the plurality of third flat tubes 301, and the plurality of first flat tubes 201 in this order, and when the outdoor heat exchanger 1 (2) acts as a condenser, the refrigerant flows through the plurality of first flat tubes 201, the plurality of third flat tubes 301, the plurality of fourth flat tubes 302, and the plurality of second flat tubes 202 in this order.

With such a configuration, when the outdoor heat exchanger 1 (2) acts as an evaporator, it is possible to maintain the refrigerant at a gas-liquid two-phase state so as to allow the refrigerant to exchange heat with the air without lowering the flow rate. When the outdoor heat exchanger 1 (2) acts as a condenser, it is possible for the high-temperature high-pressure gas refrigerant to firstly flow through the plurality of first flat tubes 201 arranged in the upper windward main heat exchanger 11 where the frost is most likely to occur, which makes it possible to effectively defrost the frost.

Preferably, the number of the first flat tubes 201 is greater than the number of the second flat tubes 202, and the plurality of the first flat tubes 201 are disposed above the plurality of the second flat tubes 202 in the group of windward flat tubes; the number of the plurality of third flat tubes 301 is greater than the number of the plurality of fourth flat tubes 302, and the plurality of the third flat tubes 301 are disposed above the plurality of the fourth flat tubes 302 in the group of leeward flat tubes.

With such a configuration, the plurality of second flat tubes 202 in the group of windward flat tubes and the plurality of fourth flat tubes 302 in the group of leeward flat tubes are positioned below and have a small contact area with the air, and thereby are not affected by the air flowing through for heat exchange. As a result, the heat is suitably exchanged between the refrigerant and the plurality of first flat tubes 201 in the group of windward flat tubes and the plurality of third flat tubes 301 in the group of leeward flat tubes where the air has a greater flow rate.

Preferably, in the outdoor heat exchanger 1, in the group of windward flat tubes, one ends of the plurality of first flat tubes 201 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction, and one ends of the plurality of second flat tubes 202 opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction, and in the group of leeward flat tubes, one ends of the plurality of third flat tubes 301 opposite to the other ends where the distributor 10 is connected are connected to each other in pairs in the vertical direction, and one ends of the plurality of fourth flat tubes 302 opposite to the other ends where the distributor 10 is connected are connected to each other in pairs in the vertical direction; in the group of windward flat tubes and the group of leeward flat tubes, the other ends of the plurality of first flat tubes 201 opposite to the ends that are connected to each other in pairs in the vertical direction and the other ends of the plurality of third flat tubes 301 opposite to the ends that are connected to each other in pairs in the vertical direction are connected to each other alternately, and the other ends of the plurality of second flat tubes 202 opposite to the ends that are connected to each other in pairs in the vertical direction and the other ends of the plurality of fourth flat tubes 302 opposite to the ends that are connected to each other in pairs in the vertical direction are connected to each other alternately.

With such a configuration, the flow path through which the refrigerant flows is made longer in the outdoor heat exchanger 1, which makes it possible to ensure sufficient time for suitable heat exchange.

Preferably, in the outdoor heat exchanger 2, a first end of each flat tube 20 in the group of windward flat tubes opposite to the other end where the refrigerant flows in and out is connected to a second end of a corresponding flat tube 30 in the group of leeward flat tubes group opposite to the other end where the distributor 50 is connected.

With such a configuration, in the outdoor heat exchanger 2, since the refrigerant flows through the flat tube 20 and the flat tube 30 in the same direction and the temperatures of the adjacent flat tubes in the vertical direction are close to each other, it is possible to prevent the internal heat exchange from being performed in the refrigerant, thereby improving the heat exchange performance.

Preferably, the outdoor heat exchanger 2 further includes a plate laminate 60 that connects the first end 20e and the second end 30e which are not coaxial to each other with respect to the flow direction of the refrigerant. The plate laminate 60 includes a first convex portion 61B protruding outward from the main body 61A of the first plate member 61 of the plate laminate 60 in response to each flat tube 20 in group of windward flat tubes, and a second convex portion 61C protruding outward from the main body 61A of the first plate member 61 of the plate laminate 60 in response to each flat tube 30 in the group of leeward flat tubes.

With such a configuration, since the plate laminate 60 is provided with a convex-shaped channel, it is possible to increase the channel space and reduce the pressure loss as compared with a channel formed with the same number of parts and weight.

Preferably, the outdoor heat exchanger 2 further includes a plate laminate 600 that connects the first end 20e and the second end 30e which are coaxial to each other with respect to the flow direction of the refrigerant. The plate laminate 600 includes a third convex portion 610B protruding outward from the main body 610A of the first plate member 610 of the plate laminate 600 in response to each flat tube 20 in the group of windward flat tubes and each flat tube 30 in the group of leeward flat tubes.

With such a configuration, since the plate laminate 600 is provided with a convex-shaped channel, it is possible to increase the channel space and reduce the pressure loss as compared with a channel formed with the same number of parts and weight.

Preferably, the distributor 10 (50) is provided with convex portions 110A, 110B (210A, 210B, 210C, 210D, 210E, 210F) protruding outward from the main body 111 (211) of the distributor, and a channel through which the refrigerant flows is formed in each of the convex portions 110A, 110B (210A, 210B, 210C, 210D, 210E, 210F).

With such a configuration, the distributor 10 (50) is formed with a channel protruding outward from the main body 111 (211). Therefore, it is possible to downsize the distributor 10 (50) by reducing the overall thickness thereof as compared with a conventional distributor in which the channel is formed by a through hole provided on the main body 111 (211).

Preferably, the distributor 10 (50) includes a plurality of plate members, each of which is provided with holes.

With such a configuration, it is possible to suitably form a flow path for the refrigerant by combining the holes on each plate member in the distributor 10 (50).

Preferably, the heat exchanger further includes a plurality of first fins 71 provided on the plurality of first flat tubes 201 and the plurality of second flat tubes 202, and a plurality of second fins 72 provided on the plurality of third flat tubes 301 and the plurality of fourth flat tubes 302, and an interval between the plurality of first fins 71 is larger than an interval between the plurality of second fins 72.

With such a configuration, it is possible to delay the time until the plurality of first fins 71 are clogged by the frost on the windward side where the frost is likely to occur while preventing the heat exchange performance of the outdoor heat exchanger 1 (2) from being deteriorated in the evaporator flow, and it is also possible to easily defrost the frost in the condenser flow and discharge the generated water to a lower portion of the outdoor heat exchanger 1 (2). Thus, it is possible to shorten the defrosting time and improve the heat exchange performance of the outdoor heat exchanger 1 (2).

The air conditioner 100 of the present disclosure includes the outdoor heat exchanger 1 (2) described above. With such a configuration, in the air conditioner 100, when the outdoor heat exchanger 1 (2) acts as an evaporator, it is possible to maintain the refrigerant at a gas-liquid two-phase state so as to allow the refrigerant to exchange heat with the air without lowering the flow rate. In the air conditioner 100, when the outdoor heat exchanger 1 (2) acts as a condenser, it is possible for the high-temperature high-pressure gas refrigerant to firstly flow through the plurality of first flat tubes 201 arranged in the upper windward main heat exchanger 11 where the frost is most likely to occur, which makes it possible to effectively defrost the frost.

<Modification>

The distributor 10 (50) has a configuration in which the refrigerant flows through a channel protruding outward from the main body 111 (211). The distributor 10 (50) may have a hollow portion provided on the plate member and the hollow portion may be used as a channel for the refrigerant to flow. In the distributor 10 (50), instead of the convex portion, a tube through which the refrigerant flows may be connected to the main body 111 (211). The distributor 10 (50) may be provided with a combination of two or more of a convex portion, a hollow portion, and a tube.

The shape of the plate members in the distributor 10 may be changed as in the distributor 50 according to the number of distributions. In the distributor 10 (50), the cross-sectional area of the flow path on the leeward side may be smaller than the cross-sectional area of the flow path on the windward side. This allows the distributor 10 (50) to prevent the refrigerant from becoming difficult to flow upward due to the gravity and to improve the flow velocity of the leeward side even when the flow rate of the refrigerant decreases due to the repetition of the branches.

It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in all respects. The scope of the present invention is defined by the terms of the claims rather than the description of the embodiments above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims

1. A heat exchanger that exchanges heat between refrigerant and air, the heat exchanger comprising:

a group of windward flat tubes including a plurality of first flat tubes spaced apart from each other and a plurality of second flat tubes spaced apart from each other;

a group of leeward flat tubes including a plurality of third flat tubes spaced apart from each other and a plurality of fourth flat tubes spaced apart from each other, the group of leeward flat tubes being disposed at a leeward position with respect to the group of windward flat tubes in a flow direction of air; and

a distributor connected to ends of the plurality of third flat tubes and configured to distribute the refrigerant flowing in from an inflow tube disposed at a central position of the distributor to the plurality of third flat tubes through a plurality of branches when the heat exchanger acts as an evaporator,

when the heat exchanger acts as an evaporator, the refrigerant flows through the plurality of second flat tubes, the plurality of fourth flat tubes, the plurality of third flat tubes, and the plurality of first flat tubes in this order, and

when the heat exchanger acts as a condenser, the refrigerant flows through the plurality of first flat tubes, the plurality of third flat tubes, the plurality of fourth flat tubes, and the plurality of second flat tubes in this order,

the distributor has a fourth convex portion protruding outward from a main body of the distributor, and

the fourth convex portion protruding outward from a main body of the distributor is formed with a channel through which the refrigerant flowing in from the inflow tube and branched by the distributor flows.

2. The heat exchanger according to claim 1, wherein

the number of the plurality of first flat tubes is greater than the number of the plurality of second flat tubes,

in the group of windward flat tubes, the plurality of first flat tubes are disposed above the plurality of second flat tubes,

the number of the plurality of third flat tubes is greater than the number of the plurality of fourth flat tubes, and

in the group of leeward flat tubes, the plurality of third flat tubes are disposed above the plurality of fourth flat tubes.

3. The heat exchanger according to claim 1, wherein

in the group of windward flat tubes, one ends of the plurality of first flat tubes opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction, and one ends of the plurality of second flat tubes opposite to the other ends where the refrigerant flows in and out are connected to each other in pairs in the vertical direction,

in the group of leeward flat tubes, one ends of the plurality of third flat tubes opposite to the other ends where the distributor is connected are connected to each other in pairs in the vertical direction, and one ends of the plurality of fourth flat tubes opposite to the other ends where the distributor is connected are connected to each other in pairs in the vertical direction,

in the group of windward flat tubes and the group of leeward flat tubes, the other ends of the plurality of first flat tubes opposite to the ends that are connected to each other in pairs in the vertical direction and the other ends of the plurality of third flat tubes opposite to the ends that are connected to each other in pairs in the vertical direction are connected to each other alternately, and the other ends of the plurality of second flat tubes opposite to the ends that are connected to each other in pairs in the vertical direction and the other ends of the plurality of fourth flat tubes opposite to the ends that are connected to each other in pairs in the vertical direction are connected to each other alternately.

4. The heat exchanger according to claim 1, wherein

a first end of each flat tube in the group of windward flat tubes opposite to the other end where the refrigerant flows in and out is connected to a second end of a corresponding flat tube in the group of leeward flat tubes group opposite to the other end where the distributor is connected.

5. The heat exchanger according to claim 4, further comprising:

a first connection member that connects the first end and the second end which are not coaxial to each other with respect to a flow direction of the refrigerant, wherein

the first connection member includes a first convex portion protruding outward from a main body of the first connection member in response to each flat tube in the group of windward flat tubes, and a second convex portion protruding outward from the main body of the first connection member in response to each flat tube in the group of leeward flat tubes.

6. The heat exchanger according to claim 4, further comprising:

a second connection member that connects the first end and the second end which are coaxial to each other with respect to a flow direction of the refrigerant, wherein

the second connection member includes a third convex portion protruding outward from a main body of the second connection member in response to each flat tube in the group of windward flat tubes and each flat tube in the group of leeward flat tubes.

7. (canceled)

8. The heat exchanger according to claim 1, wherein

the distributor includes a plurality of plate members, each of which is provided with holes.

9. The heat exchanger according to claim 1, further comprising:

a plurality of first fins provided on the plurality of first flat tubes and the plurality of second flat tubes; and

a plurality of second fins provided on the plurality of third flat tubes and the plurality of fourth flat tubes, wherein

an interval between the plurality of first fins is larger than an interval between the plurality of second fins.

10. An air conditioner equipped with the heat exchanger according to claim 1.

11. The heat exchanger according to claim 5, wherein

the first connection member is composed of a plurality of plate members,

the plurality of plate members includes a first plate member formed with the first convex portion and the second convex portion, and a second plate member formed with a stepped hole that connects a channel formed inside the first convex portion and a channel formed inside the second convex portion.