AU2017226110B2

AU2017226110B2 - Heat exchanger and air conditioner

Info

Publication number: AU2017226110B2
Application number: AU2017226110A
Authority: AU
Inventors: Yasutaka Aoki; Yohei Katsurayama; Masayuki Sakai; Hideaki Tatenoi
Original assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2016-02-29
Filing date: 2017-02-17
Publication date: 2020-04-16
Anticipated expiration: 2037-02-17
Also published as: AU2017226110A1; WO2017150219A1; EP3382316A1; EP3382316A4; EP3382316B1; JP6611335B2; JP2017155990A; CN108474633A

Abstract

Provided is a heat exchanger which is equipped with first heat transfer tubes (21), a first header (52), second heat transfer tubes (23), a second header (53), and a plurality of communication paths (61, 71) that each have one end connected to the first header (52) and the other end connected to the second header (53) so as to allow communication between the first header (52) and the second header (53). The height positions where said ends of the communication paths (61, 71) are connected to the first header (52) are the same as each other. The height positions where the other ends of the communication paths (61, 71) are connected to the second header (53) are different from each other.

Description

DESCRIPTION

Title of Invention

HEAT EXCHANGER AND AIR CONDITIONER

Technical Field

[0001]

The present invention relates to a heat exchanger

and an air conditioner.

This application claims priority from Japanese

Patent Application No. 2016-038328 filed on February 29,

2016; the contents of which are incorporated herein by

reference.

Background Art

[0002]

A reference herein to a patent document or any

other matter identified as prior art, is not to be taken

as an admission that the document or other matter was

known or that the information it contains was part of the

common general knowledge as at the priority date of any

of the claims.

[0002a]

Where any or all of the terms "comprise",

"comprises", "comprised" or "comprising" are used in this

specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

[0002b]

A heat exchanger, in which a plurality of heat

transfer tubes extending in a horizontal direction are

disposed at intervals in a vertical direction and a fin is

provided on an outer surface of each heat transfer tube,

is known as a heat exchanger of an air conditioner. Both

ends of the plurality of heat transfer tubes are connected

to a pair of headers extending in the vertical direction,

respectively. Such a heat exchanger is configured such

that a refrigerant, which is introduced into one header

and is circulated in the other header via the heat

transfer tubes, turns back at the other header to return

to one header again via the heat transfer tubes, in order

to secure a flow passage length for the refrigerant.

[00031

The inside of the header at a turnback side is

partitioned into a plurality of regions with a partition

plate partitioning the inside of the header in the

vertical direction. Accordingly, a refrigerant introduced

in one region of the header via the heat transfer tubes

returns to one header on an entrance side via the plurality of heat transfer tubes connected to the other region after being introduced into the other region of the header via a connection pipe.

For example, a heat exchanger having the connection

pipe connected to a lower portion of each region of a

header, into which a refrigerant that has turned back is

introduced, is disclosed in PTL 1.

Citation List

Patent Literature

[00041

[PTL 1] Japanese Patent No. 5071597

Summary of Invention

[0005]

However, in a case where the heat exchanger is used

as an evaporator, not the entire refrigerant, which is

introduced into one region of the header via heat transfer

tubes, evaporates, and the refrigerant is in a state of a

gas-liquid two phase refrigerant, in which a liquid phase

refrigerant and a gas phase refrigerant are mixed. In a

case where such a gas-liquid two phase refrigerant is

introduced in a lower portion of the other region of the

header via the connection pipe, a liquid phase refrigerant

with a high density is unlikely to reach upper heat

transfer tubes. For this reason, a refrigerant flowing in

the upper heat transfer tubes is a liquid phase refrigerant having a lower flow rate. As a consequence, there is a problem that the heat exchanger does not show a desired performance.

[00061

It is desirable to provide a heat exchanger which

can suppress a performance decrease and an air conditioner

in which the heat exchanger is used.

[00071

In order to solve the problems, the invention adopts

the following means.

According to a first aspect of the invention, there

is provided a heat exchanger comprising a plurality of

first heat transfer tubes that extend in a horizontal

- 3a - direction to allow a refrigerant to circulate therein, and are arranged at intervals in a vertical direction, a first header part that has a cylindrical shape extending in the vertical direction and is connected to one end of each of the first heat transfer tubes in a communicating state, a plurality of second heat transfer tubes that extend in the horizontal direction to allow the refrigerant to circulate therein, and are arranged at intervals in the vertical direction, a second header part that has a cylindrical shape extending in the vertical direction and is connected to one end of each of the second heat transfer tubes in a communicating state, and a plurality of communication paths each of which has one end connected to the first header part and the other end connected to the second header part so as to allow the first header part to communicate with the second header part. A connection point of one end of each of one end of the communication paths to the first header part is at a height position which is the same for each of the communication paths, and a connection point of the other end of each of the communication paths to the second header part is at a height position different for each of the communication paths.

[0008]

In such a heat exchanger, the refrigerant introduced in the first header part via the first heat transfer tubes is introduced into the communication paths connected to the same vertical position of the first header part.

Herein, a liquid phase is likely to stay in a lower

portion of the first header part and a gas phase is likely

to stay in an upper portion of the first header part due

to a density difference between a gas and a liquid in the

refrigerant. For this reason, a difference in the gas

liquid ratios of refrigerants occurs in the vertical

direction in the first header part.

In the heat exchanger of the invention, the

plurality of communication paths connected to the second

header part are connected to the same vertical position in

the first header part. Therefore, refrigerants with

almost the same gas-liquid ratio are introduced into each

communication path. For this reason, the uniformization

of flow rates of refrigerants for the plurality of

respective communication paths can be achieved. Since the

connection points of the plurality of communication paths

to the second header part are at vertical positions

different from each other, refrigerants with almost the

same gas-liquid ratio are introduced from the plurality of

height positions in the second header part into the second

header part. Accordingly, since the refrigerants are

mixed in the second header part in the vertical direction, a gas-liquid ratio of the refrigerant over the entire area in the second header part in the vertical direction can be homogenized. Accordingly, the uniformization of mass flow rates of refrigerants introduced into the respective second heat transfer tubes can be achieved.

[0009]

The heat exchanger may further include a

partitioning plate that partitions a space in the second

header part into upper and lower regions vertically

separated from each other between connection points of the

communication paths to the second header part, which are

vertically adjacent to each other, and has a

communication-hole formed vertically therethrough.

[0010]

In a case where there is no partitioning plate, a

liquid phase with a high density is likely to go downwards

and a gas phase with a low density is likely to go upwards

in the second header part. Therefore, a difference in the

mass flow rate in the vertical direction occurs in the

second header part as a whole in some cases. On the

contrary, a refrigerant is allowed to circulate through

the respective regions and a refrigerant is likely to stay

in each region at the same time by dividing the inside of

the second header part into small regions with the

partitioning plate having the communication-hole.

Therefore, a density difference of a refrigerant in the

second header part as a whole in the vertical direction

can be reduced.

[0011]

In the heat exchanger, the connection points having

the height positions different from each other of the

plurality of communication paths may be present in the

respective regions partitioned with the partitioning plate.

[00121

Accordingly, a density difference of a refrigerant

in each region can be further reduced since the

refrigerant in each region is caused to be mixed.

[0013]

The heat exchanger may further include a connection

pipe that has a main pipe portion, of which one end is

connected to the first header part and in which a

plurality of split flow passages arranged in the

horizontal direction are formed, and branch pipe portions,

which branch off into a plurality of portions from the

other end side of the main pipe portion, in which branch

flow passages are formed so as to communicate with the

split flow passages, and each of which is connected to the

second header part. Each of the communication paths may

be a flow passage formed by each of the split flow

passages and each of the branch flow passages.

[00141

Consequently, construction is easy compared to a

case where each communication path is configured of a

separate individual connection pipe since there is one

construction point to the first header part in the case of

the branch connection pipe.

[0015]

The heat exchanger may further include a header that

has a header body which has a cylindrical shape extending

in the vertical direction and a main partition plate which

partitions an inside of the header body into upper and

lower parts. The first header part may be a portion below

the main partition plate in the header, and the second

header part may be a portion above the main partition

plate in the header.

[0016]

The heat exchanger having the first header part and

the second header part can be easily configured by forming

the first header part and the second header part with the

main partition plate in one header part.

[0017]

According to a second aspect of the invention, there

is provided an air conditioner including any one of the

heat exchangers described above.

[0018]

Accordingly, a decrease in a heat exchange

performance caused by inhomogeneous distribution of the

refrigerant is suppressed, and thus the air conditioner

with a high efficiency can be provided.

Advantageous Effects of Invention

[0019]

The heat exchanger and the air conditioner of the

invention can achieve the suppression of an efficiency

decrease.

Brief Description of Drawings

[0020]

Fig. 1 is an overall configuration view of an air

conditioner according to a first embodiment of the

invention.

Fig. 2 is a longitudinal sectional view of a heat

exchanger according to the first embodiment of the

invention.

Fig. 3 is a perspective view of the heat exchanger

according to the first embodiment of the invention.

Fig. 4 is a side view of a turnback side header and

a branch connection pipe of a heat exchanger according to

a second embodiment of the invention.

Fig. 5A is a view illustrating a sectional shape of

a flow passage of a main pipe portion in the branch

connection pipe of the heat exchanger according to the second embodiment of the invention.

Fig. 5B is a view illustrating the sectional shape

of the flow passage of the main pipe portion in the branch

connection pipe of the heat exchanger according to the

second embodiment of the invention.

Fig. 6 is a side view of a turnback side header and

a connection pipe of a heat exchanger according to a third

embodiment of the invention.

Fig. 7 is a side view of a turnback side header and

a connection pipe of a heat exchanger according to a

fourth embodiment of the invention.

Fig. 8 is a side view of a turnback side header and

a connection pipe of a heat exchanger according to a fifth

embodiment of the invention.

Description of Embodiments

[0021]

Hereinafter, an air conditioner including a heat

exchanger according to a first embodiment of the invention

will be described with reference to Figs. 1 to 3.

As illustrated in Fig. 1, an air conditioner 1

includes a compressor 2, an indoor heat exchanger 3 (heat

exchanger 10), an expansion valve 4, an outdoor heat

exchanger 5 (heat exchanger 10), a four-way valve 6, and a

pipe 7 that connects the configuration elements together,

and a refrigerant circuit formed of the configuration elements is configured.

[00221

The compressor 2 compresses a refrigerant and

supplies the compressed refrigerant to the refrigerant

circuit.

The indoor heat exchanger 3 performs heat exchange

between the refrigerant and indoor air. The indoor heat

exchanger 3 is used as an evaporator to absorb heat from

the inside during cooling operation, and is used as a

condenser to radiate heat to the inside during heating

operation.

The expansion valve 4 reduces a pressure by

expanding the high-pressure refrigerant liquefied by the

condenser exchanging heat.

The outdoor heat exchanger 5 performs heat exchange

between the refrigerant and outdoor air. The outdoor heat

exchanger is used as a condenser to radiate heat to the

outside during cooling operation and is used as an

evaporator to absorb heat from the outside during heating

operation.

The four-way valve 6 switches between directions

where a refrigerant circulates during heating operation

and during cooling operation. Consequently, a refrigerant

circulates in the compressor 2, the outdoor heat exchanger

5, the expansion valve 4, and the indoor heat exchanger 3 in this order during cooling operation. On the other hand, a refrigerant circulates in the compressor 2, the indoor heat exchanger 3, the expansion valve 4, and the outdoor heat exchanger 5 in this order during heating operation.

[0023]

Next, the heat exchangers 10 which are used as the

indoor heat exchanger 3 and the outdoor heat exchanger 5

will be described with reference to Figs. 2 and 3.

The heat exchangers 10 each include a plurality of

heat transfer tubes 20, a plurality of fins 28, a pair of

headers 30, a first connection pipe 60, and a second

connection pipe 70.

[0024]

The heat transfer tubes 20 are tubular members

linearly extending in a horizontal direction, and flow

passages through which a refrigerant circulates are formed

therein. The plurality of heat transfer tubes 20 are

arranged at intervals in a vertical direction, and are

disposed so as to be parallel to each other.

In the embodiment, the heat transfer tubes 20 each

have a flat tubular shape, and the plurality of flow

passages arranged in the horizontal direction orthogonal

to an extending direction of the heat transfer tubes 20

are formed inside the heat transfer tubes 20. The

plurality of flow passages are arranged so as to be parallel to each other. Consequently, a sectional shape orthogonal to the extending direction of the heat transfer tubes 20 is a flat shape of which a longitudinal direction is the horizontal direction orthogonal to the extending direction of the heat transfer tubes 20.

[0025]

The fins 28 each are disposed between the heat

transfer tubes 20 arranged as described above, and extend

in a so-called corrugated shape so as to be alternately in

contact with the vertically nearby heat transfer tubes 20

as facing the extending direction of each of the heat

transfer tubes 20 in the embodiment. Without being

limited thereto, the shapes of the fins 28 may be any

shape insofar as the fins are provided so as to protrude

from outer peripheral surfaces of the heat transfer tubes

20.

[0026]

At both ends of the plurality of heat transfer tubes

20, the pair of headers 30 is provided such that the heat

transfer tubes 20 are sandwiched therebetween. One of the

pair of headers 30 is set as an entrance side header 40,

which is an entrance of a refrigerant from the outside

into the heat exchanger 10, and the other one is set as a

turnback side header 50 for a refrigerant to turn back in

the heat exchanger 10.

[00271

The entrance side header 40 is a cylindrical member

extending in the vertical direction. An upper end and a

lower end of the entrance side header are closed and the

inside of the entrance side header is partitioned into two

upper and lower regions with a partition plate 41. The

lower region partitioned with the partition plate 41 is

set as a lower entry region 42 and the upper region is set

as an upper entry region 43. The lower entry region 42

and the upper entry region 43 are in a state of not

communicating with each other in the entrance side header

40. The lower entry region 42 and the upper entry region

43 each are connected to the pipe 7 configuring the

refrigerant circuit.

Herein, out of the plurality of heat transfer tubes

20, the heat transfer tubes 20 connected to the lower

entry region 42 in a communicating state are set as first

heat transfer tubes 21, and the heat transfer tubes 20

connected to the upper entry region 43 in a communicating

state are set as second heat transfer tubes 23.

[0028]

The turnback side header 50 includes a header body

51 and a main partition plate 58.

The header body 51 is a cylindrical member extending

in the vertical direction, and an upper end and a lower end of the header body are closed. The main partition plate 58 is provided in the header body 51, and partitions a space in the header body 51 into two upper and lower regions. A portion below the main partition plate 58 of the header body 51 is set as a first header part 52, and a portion above the main partition plate 58 of the header body 51 is set as a second header part 53. That is, in the embodiment, the first header part 52 and the second header part 53 each of which has a space therein are formed in the turnback side header 50 by the inside of the header body 51 being partitioned with the main partition plate 58. In other words, the turnback side header 50 is configured with the first header part 52 and the second header part 53.

[0029]

The plurality of first heat transfer tubes 21 each

are connected to the first header part 52 so as to be in a

communicating state with the inside of the first header

part 52. That is, the heat transfer tubes 20 connected to

the first header part 52 are set as the first heat

transfer tubes 21.

The plurality of second heat transfer tubes 23 each

are connected to the second header part 53 so as to be in

a communicating state with the inside of the second header

part 53. That is, the heat transfer tubes 20 connected to the second header part 53 are set as the second heat transfer tubes 23.

[0030]

The first connection pipe 60 is a tubular member in

which a flow passage is formed. One end of the first

connection pipe is connected to the first header part 52

in a communicating state with the inside of the first

header part 52, and the other end is connected to the

second header part 53 in a communicating state with the

inside of the second header part 53. More specifically,

one end of the first connection pipe 60 is connected to an

upper portion of the first header part 52. In addition,

the other end of the first connection pipe 60 is connected

to a lower portion of the second header part 53. In the

embodiment, the flow passage in the first connection pipe

is set as a first communication path 61 (communication

path) that connects the first header part 52 and the

second header part 53 together.

[0031]

The second connection pipe 70 is a tubular member in

which a flow passage is formed. One end of the second

connection pipe is connected to the first header part 52

in a communicating state with the inside of the first

header part 52 as in the first connection pipe 60. On the

other hand, the other end of the second connection pipe 70 is connected to the second header part in a communicating state with the inside of the second header part 53. More specifically, one end of the second connection pipe 70 is connected to the upper portion of the first header part 52.

In addition, the other end of the second connection pipe

is connected to an upper portion of the second header

part 53. In the embodiment, the flow passage in the

second connection pipe 70 is set as a second communication

path 71 (communication path) that connects the first

header part 52 and the second header part 53 together.

[00321

Herein, a connection point of the first connection

pipe 60 to the first header part 52 and a connection point

of the second connection pipe 70 to the first header part

52 are at the same vertical position, in the embodiment.

That is, the connection point of the first connection pipe

to the first header part 52 is disposed so as to be

adjacent to or to be spaced apart from the connection

point of the second connection pipe 70 to the first header

part 52 in the horizontal direction, and has the same

vertical position as the connection point of the second

connection pipe to the first header part.

"The same vertical position" is not limited to a

case where the vertical position of a center of the

connection point of the first connection pipe 60 to the first header part 52 and the vertical position of a center of the connection point of the second connection pipe 70 to the first header part 52 are the same, and it is sufficient that at least a part of the connection point of the first connection pipe 60 to the first header part 52 and a part of the connection point of the second connection pipe 70 to the first header part 52 overlap each other in the vertical direction.

[0033]

In the embodiment, the connection point of the

second connection pipe 70 to the second header part 53 is

provided above the connection point of the first

connection pipe 60 to the second header part 53, that is,

the connection point of the first connection pipe 60 to

the second header part 53 and the connection point of the

second connection pipe 70 to the second header part 53 are

at vertical positions different from each other.

[0034]

Next, operation and effects in a case where the heat

exchanger 10 is used as an evaporator will be described.

In a case where the heat exchanger 10 is the indoor heat

exchanger 3, the heat exchanger is used as an evaporator

during cooling operation of the air conditioner 1, and in

a case where the heat exchanger is the outdoor heat

exchanger 5, the heat exchanger is used as an evaporator during heating operation of the air conditioner 1.

[0035]

When the heat exchanger 10 is used as an evaporator,

a gas-liquid two phase refrigerant having a high liquid

phase content is supplied from the pipe 7 to the lower

entry region 42 of the entrance side header 40 illustrated

in Fig. 2. The refrigerant is divided and supplied to the

plurality of first heat transfer tubes 21 in the lower

entry region 42, and exchanges heat with the external

atmosphere of the first heat transfer tubes 21 in the

process of circulating in the first heat transfer tubes 21,

thereby causing evaporation. Consequently, the

refrigerant supplied from the first heat transfer tubes 21

into the first header part 52 of the turnback side header

becomes a gas-liquid two phase refrigerant, in which

the proportion of a liquid phase has dropped, by some of

the refrigerant changing from the liquid phase to a gas

phase.

[0036]

Out of gas-liquid two phase refrigerants supplied

into the first header part 52, a refrigerant with a high

liquid phase content and a high density gathers at the

lower portion of the first header part 52 due to gravity,

and a refrigerant with a high gas phase content and a low

density gathers at the upper portion of the first header part 52. That is, in the first header part 52, the gas liquid ratio (density) of a refrigerant differs according to a vertical position. Herein, if the connection point of the first connection pipe 60 to the first header part

52 and the connection point of the second connection pipe

to the first header part 52 are different from each

other in the vertical direction, the gas-liquid ratios of

refrigerants introduced into the first connection pipe 60

and the second connection pipe 70 are different from each

other. As a consequence, as a result of a refrigerant

with a high density being introduced into one of the first

connection pipe 60 and the second connection pipe 70,

which is connected to a lower part of the first header

part 52, the mass flow rate of the refrigerant becomes

higher. In addition, as a result of a refrigerant with a

low density being introduced into one of the first

connection pipe 60 and the second connection pipe 70,

which is connected to an upper part of the first header

part 52, the mass flow rate of the refrigerant becomes

lower.

[00371

On the contrary, in the embodiment, the connection

point of the first connection pipe 60 to the first header

part 52 and the connection point of the second connection

pipe 70 to the first header part 52 are at the same vertical position. For this reason, refrigerants having almost the same gas-liquid ratio are introduced into the first connection pipe 60 and the second connection pipe 70 respectively. As a consequence, the gas-liquid ratios of the refrigerants introduced into the vertical positions of the second header part 53 different from each other via the first connection pipe 60 and the second connection pipe 70 respectively are almost the same. That is, the uniformization of the mass flow rates of refrigerants circulating in the first connection pipe 60 and the second connection pipe 70 is achieved.

[0038]

In the embodiment, refrigerants having almost the

same gas-liquid ratio are introduced into the second

header part 53 from a plurality of height positions of the

second header part 53. Accordingly, since the

refrigerants are mixed in the second header part 53 in the

vertical direction, a gas-liquid ratio of the refrigerant

over the entire area in the second header part 53 in the

vertical direction can be homogenized. Accordingly, the

uniformization of mass flow rates of refrigerants

introduced into the respective second heat transfer tubes

23 can be achieved.

[0039]

After then, a refrigerant introduced in the second header part 53 via the first connection pipe 60 or the second connection pipe 70 is diverted to the plurality of second heat transfer tubes 23 connected thereto and circulates in the second heat transfer tubes 23. Then, the refrigerant again causes evaporation by exchanging heat with the external atmosphere of the second heat transfer tubes 23 in the process of circulating in the second heat transfer tubes 23. Consequently, in the second heat transfer tubes 23, the remaining liquid phase in the refrigerant changes to the gas phase and the refrigerant in a gas phase state is supplied to the upper entry region 43 of the entrance side header 40. Then, the refrigerant is introduced from the upper entry region 43 to the pipe 7, thereby circulating in the refrigerant circuit.

[0040]

As described above, in the heat exchanger 10 of the

invention, the first communication path 61 of the first

connection pipe 60 and the second communication path 71 of

the second connection pipe 70, each of which is connected

to one of the second header part 53, are connected to the

first header part 52 at the same vertical position.

Therefore, refrigerants with almost the same gas phase

liquid phase ratio are introduced into respective

communication paths 102. For this reason, the uniformization of flow rates of refrigerants for the plurality of respective communication paths 102 can be achieved. Refrigerants introduced in the second header part 53 via the first connection pipe 60 and the second connection pipe 70 are caused to be mixed in the second header part 53 in the vertical direction. Accordingly, the homogenization of a gas-liquid ratio in the second header part 53 can be further achieved. As a consequence, for example, in a case where the heat exchanger 10 is used as an air conditioner, a cooling performance and a heating performance are not impaired.

[0041]

Next, a heat exchanger 80 according to a second

embodiment of the invention will be described with

reference to Fig. 4, Fig. 5A, and Fig. 5B. In the second

embodiment, the same configuration elements as the first

embodiment will be assigned with the same reference signs

as the first embodiment, and the detailed description

thereof will be omitted.

As illustrated in Fig. 4, the heat exchanger 80 of

the second embodiment is different from the heat exchanger

of the first embodiment in that one branch connection pipe

81 is included instead of the first connection pipe 60 and

the second connection pipe 70 of the first embodiment.

[00421

The branch connection pipe 81 has a main pipe

portion 82 and a plurality of (two, in the embodiment)

branch pipe portions 85.

One end of the main pipe portion 82 is connected to

the first header part 52. In the first header part 52,

two split flow passages 83, which are formed by splitting

the inside of the first header part 52 in the horizontal

direction into two regions, are formed as illustrated in

Fig. 5A and Fig. 5B. The split flow passages 83 are

arranged in the horizontal direction so as to extend from

one end to the other end of the main pipe portion 82. As

illustrated in Fig. 5A, the main pipe portion 82 may have

a structure in which the two split flow passages 83 are

formed by providing a split wall portion 84 in the middle

of a circular section of the flow passage in the

horizontal direction. In addition, as illustrated in Fig.

5B, the main pipe portion may have a structure in which

the split flow passages 83 obtained by linearly cutting

out a part of the circular section of the flow passage are

provided so as to be arranged side by side via the split

wall portion 84 configuring the linear portion.

[0043]

The two branch pipe portions 85 are provided so as

to branch off into a plurality of portions from the other

end side of the main pipe portion 82. One branch pipe portion of the two branch pipe portions 85 is connected to the lower portion of the second header part 53. The other branch pipe portion of the two branch pipe portions 85 is connected to the upper portion of the second header part

53. In addition, branch flow passages 86, which are flow

passages inside the respective branch pipe portions 85,

communicate with the split flow passages 83 in the main

pipe portion 82 in a one-to-one relationship. Accordingly,

out of the two split flow passages 83 of the main pipe

portion 82, one split flow passage 83 is in a

communicating state with the lower portion of the second

header part 53 via one branch flow passage 86, that is,

the first communication path 61 that allows the first

header part 52 to communicate with the lower portion of

the second header part 53 by means of one split flow

passage 83 and one branch flow passage 86 is formed. In

addition, the other split flow passage 83 is in a

communicating state with the inside of the upper portion

of the second header part 53 via the other branch flow

passage 86, that is, the second communication path 71 that

allows the first header part 52 to communicate with the

upper portion of the second header part 53 by means of the

other split flow passage 83 and the other branch flow

passage 86 is formed.

[00441

In such a heat exchanger 80 of the second embodiment,

the two split flow passages 83 in the main pipe portion 82

of the branch connection pipe 81 are arranged in the

horizontal direction side by side. Therefore,

refrigerants with almost the same density are introduced

into the two split flow passages 83. Then, the

refrigerants are introduced into the lower portion and the

upper portion of the second header part 53 via the

respective branch flow passages 86. Thus, the

homogenization of mass flow rates of refrigerants

introduced into the second header part 53 can be achieved

as in the first embodiment.

[0045]

In addition, since there is only one connection

point to the first header part 52, construction can be

performed more easily compared to a case where the first

connection pipe 60 and the second connection pipe 70 are

separately provided as in the first embodiment.

Although one of the two branch pipe portions 85 is

connected to the lower portion of the second header part

53 and the other one is connected to the upper portion of

the second header part 53 in the embodiment, it is

sufficient that the connection points of the two branch

pipe portions 85 to the second header part 53 are

different from each other in the vertical direction.

[0046]

Next, a heat exchanger 90 according to a third

embodiment of the invention will be described with

reference to Fig. 6. In the third embodiment, the same

configuration elements as the first embodiment will be

assigned with the same reference signs as the first

embodiment, and the detailed description thereof will be

omitted.

As illustrated in Fig. 6, the heat exchanger 90 of

the third embodiment is different from the first

embodiment in that a partitioning plate 91 is further

included in the second header part 53.

[0047]

The partitioning plate 91 is provided at a vertical

position between the first connection pipe 60 and the

second connection pipe 70 in the second header part 53,

and partitions the inside of the second header part 53

into two upper and lower regions. A lower region, out of

the two regions, is set as a second header lower region 93.

The other end of the first connection pipe 60 is connected

to the second header lower region 93 in a communicating

state. In addition, an upper region, out of the two

regions, is set as a second header upper region 94. The

other end of the second connection pipe 70 is connected to

the second header upper region 94 in a communicating state.

[0048]

The partitioning plate 91 has a communication-hole

92 formed in the vertical direction. The communication

hole 92 allows the second header lower region 93 and the

second header upper region 94, which are partitioned with

the partitioning plate 91, to be in a communicating state.

A position at which the communication-hole 92 is formed

may be the middle of the partitioning plate 91 in the

horizontal direction, or may be a position off the middle.

[0049]

In a case where there is no partitioning plate 91, a

liquid phase with a high density is likely to go downwards

and a gas phase with a low density is likely to go upwards

in the second header part 53. Therefore, a difference in

the mass flow rate in the vertical direction occurs in the

second header part 53 as a whole. On the contrary, in the

embodiment, refrigerants are allowed to circulate through

the respective regions and a refrigerant of each region is

likely to stay in each region at the same time by dividing

the inside of the second header part 53 into small regions

with the partitioning plate 91 having the communication

hole 92. That is, the movement of the gas phase content

of a refrigerant from the second header lower region 93 to

the second header upper region 94 is inhibited by the

partitioning plate 91. On the other hand, the movement of the liquid phase content of a refrigerant from the second header upper region 94 to the second header lower region

93 is inhibited by the partitioning plate 91. As a

consequence, a tendency in which the liquid phase is

likely to stay in the lower portion and the gas phase is

likely to stay in the upper portion in the second header

part 53 as a whole can be suppressed. Accordingly, a

density difference of a refrigerant in the second header

part 53 as a whole in the vertical direction can be

reduced.

[0050]

Next, a heat exchanger 100 according to a fourth

embodiment of the invention will be described with

reference to Fig. 7. In the fourth embodiment, the same

configuration elements as the first and third embodiments

will be assigned with the same reference signs as the

embodiments, and the detailed description thereof will be

omitted.

As illustrated in Fig. 7, the heat exchanger 100 of

the embodiment has two partitioning plates 91 provided in

the second header part 53. That is, the partitioning

plates 91 are provided at intervals in the vertical

direction, and accordingly a region in the second header

part 53 is partitioned into three regions in the vertical

direction. The same communication-holes 92 as in the third embodiment are formed in the partitioning plates 91.

[0051]

Three connection pipes 101 that connect the first

header part 52 and the three regions in the second header

part 53 together respectively are provided in the

embodiment. A flow passage in each of the connection

pipes 101 is set as each of the communication paths 102

allowing the first header part 52 to communicate with the

second header part 53.

The connection points of the three connection pipes

101 to the first header part 52 are at the same vertical

position, as in the first embodiment. The other end of

the first connection pipe 101, out of the three connection

pipes 101, is connected to the lowermost region, out of

the three regions in the second header part 53. The other

end of the second connection pipe 101, out of the three

connection pipes 101, is connected to the middle region,

out of the three regions in the second header part 53.

The other end of the third connection pipe 101, out of the

three connection pipes 101, is connected to the uppermost

region, out of the three regions in the second header part

53.

[00521

In the embodiment, since the inside of the second

header part 53 is divided into the three regions by the partitioning plate 91, a deviation in the density of a refrigerant in the second header part 53 can be suppressed more than the third embodiment.

The inside of the second header part 53 may be

partitioned into four or more regions and four or more

connection pipes 101 may be provided according to the

number of the partitioned regions. A density difference

of a refrigerant in the second header part 53 as a whole

can be further reduced by subdividing the inside of the

second header part 53.

[0053]

Next, a heat exchanger 110 according to a fifth

embodiment of the invention will be described with

reference to Fig. 8. In the fifth embodiment, the same

configuration elements as the first and third embodiments

will be assigned with the same reference signs as the

first embodiment, and the detailed description thereof

will be omitted.

[0054]

As illustrated in Fig. 8, the heat exchanger 110 of

the embodiment has one partitioning plate 91 provided in

the second header part 53, as in the third embodiment.

Accordingly, the inside of second header part 53 is

partitioned into two regions in the vertical direction.

The same communication-hole 92 as in the third embodiment is formed in the partitioning plate 91.

[0055]

Six connection pipes 101 that connect the first

header part 52 and the second header part 53 together are

provided in the embodiment. The communication paths 102

are formed in the connection pipes 101, and the connection

points of all the communication paths to the first header

part 52 are at the same vertical position.

In addition, the other end of each of three

connection pipes 101, out of the six connection pipes 101,

is connected to the second header lower region 93. The

connection points of the three connection pipes 101 to the

second header lower region 93 are at vertical positions

different from each other.

The other end of each of remaining three connection

pipes 101, out of the six connection pipes 101, is

connected to the second header upper region 94. The

connection points of the three connection pipes 101 to the

second header upper region 94 are at vertical positions

different from each other.

[0056]

In the heat exchanger 110 of the embodiment having

the configuration described above, a refrigerant is

introduced into the second header lower region 93 and the

second header upper region 94 in the second header part 53 from the vertical positions different from each other.

Accordingly, the mixing of a refrigerant in the second

header lower region 93 and the second header upper region

94 can be further caused.

Although an example in which one partitioning plate

91 is provided is described in the embodiment, the inside

of the second header part 53 may be partitioned into three

or more regions with two or more partitioning plates 91.

In addition, the other end of each of four or more

connection pipes 101, without being limited to only three,

may be connected to each region in the second header part

53.

[0057]

Although the embodiments of the invention are

described, the invention is not limited thereto, and can

be modified as appropriate without departing from the

technical scope of the invention.

Reference Signs List

[0058]

1 air conditioner

2 compressor

3 indoor heat exchanger

4 expansion valve

5 outdoor heat exchanger

6 four-way valve

7 pipe

heat exchanger

heat transfer tube

21 first heat transfer tube

23 second heat transfer tube

28 fin

header

entrance side header

41 partition plate

42 lower entry region

43 upper entry region

turnback side header

51 header body

52 first header part

53 second header part

58 main partition plate

first connection pipe

61 first communication path

second connection pipe

71 second communication path

heat exchanger

81 branch connection pipe

82 main pipe portion

83 split flow passage

84 split wall portion heat exchanger

91 partitioning plate

92 communication-hole

93 second header lower region

94 second header upper region

100 heat exchanger

101 connection pipe

102 communication path

110 heat exchanger

Claims

Claims

[Claim 1]

A heat exchanger comprising:

a plurality of first heat transfer tubes that extend

in a horizontal direction to allow a refrigerant to

circulate therein, and are arranged at intervals in a

vertical direction;

a first header part that has a cylindrical shape

extending in the vertical direction and is connected to

one end of each of the first heat transfer tubes in a

communicating state;

a plurality of second heat transfer tubes that

extend in the horizontal direction to allow the

refrigerant to circulate therein, and are arranged at

intervals in the vertical direction;

a second header part that has a cylindrical shape

extending in the vertical direction and is connected to

one end of each of the second heat transfer tubes in a

communicating state; and

a plurality of communication paths each of which has

one end connected to the first header part and the other

end connected to the second header part so as to allow the

first header part to communicate with the second header

part, wherein a connection point of one end of each of the communication paths to the first header part is at a height position which is the same for each of the communication paths, and a connection point of the other end of each of the communication paths to the second header part is at a height position different for each of the communication paths.
[Claim 2]

The heat exchanger according to Claim 1, further

comprising:

a partitioning plate that partitions a space in the

second header part into upper and lower regions vertically

separated from each other between connection points of the

communication paths to the second header part, which are

vertically adjacent to each other, and has a

communication-hole formed vertically therethrough.
[Claim 3]

The heat exchanger according to Claim 2,

wherein the connection points having the height

positions different from each other of the plurality of

communication paths are present in the respective regions

partitioned with the partitioning plate.
[Claim 4]

The heat exchanger according to any one of Claims 1 to 3, further comprising: a connection pipe that has a main pipe portion, of which one end is connected to the first header part and in which a plurality of split flow passages arranged in the horizontal direction are formed, and branch pipe portions, which branch off into a plurality of portions from the other end side of the main pipe portion, in which branch flow passages are formed so as to communicate with the split flow passages, and each of which is connected to the second header part, wherein each of the communication paths is a flow passage formed by each of the split flow passages and each of the branch flow passages.
[Claim 5]

The heat exchanger according to any one of Claims 1

to 4, further comprising:

a header that has a header body which has a

cylindrical shape extending in the vertical direction and

a main partition plate which partitions an inside of the

header body into upper and lower parts,

wherein the first header part is a portion below the

main partition plate in the header, and

the second header part is a portion above the main

partition plate in the header.
[Claim 6]

An air conditioner comprising the heat exchanger

according to any one of Claims 1 to 5.