U.S. patent application number 13/822206 was filed with the patent office on 2013-07-11 for heat exchanger.
This patent application is currently assigned to Daikin Industries, Ltd.. The applicant listed for this patent is Akihiro Fujiwara, Takayuki Hyoudou, Ryuhei Kaji, Jihong Liu, Yoshikazu Shiraishi, Shun Yoshioka. Invention is credited to Akihiro Fujiwara, Takayuki Hyoudou, Ryuhei Kaji, Jihong Liu, Yoshikazu Shiraishi, Shun Yoshioka.
Application Number | 20130175013 13/822206 |
Document ID | / |
Family ID | 45893004 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130175013 |
Kind Code |
A1 |
Yoshioka; Shun ; et
al. |
July 11, 2013 |
HEAT EXCHANGER
Abstract
A heat exchanger includes a pair of headers extending in an
up-and-down direction to carry refrigerant, and plural flat tubes
connected to the headers at different height positions and
extending along a direction intersecting a longitudinal direction
of the headers. Each header includes a first member and a flat tube
holding member. The first member has a main flow path, and
refrigerant connection flow paths to circulate refrigerant between
the main flow path and plural refrigerant flow paths formed in the
flat tubes. The flat tube holding member holds the flat tubes. End
portions of the flat tubes are adhered to the flat tube holding
member. Intermediate flow paths interconnect the refrigerant
connection flow paths and the plural refrigerant flow paths in the
flat tubes. The intermediate flow paths are formed in at least one
of the headers and the flat tubes.
Inventors: |
Yoshioka; Shun; (Sakai-shi,
JP) ; Hyoudou; Takayuki; (Sakai-shi, JP) ;
Kaji; Ryuhei; (Sakai-shi, JP) ; Shiraishi;
Yoshikazu; (Sakai-shi, JP) ; Fujiwara; Akihiro;
(Sakai-shi, JP) ; Liu; Jihong; (Sakai-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yoshioka; Shun
Hyoudou; Takayuki
Kaji; Ryuhei
Shiraishi; Yoshikazu
Fujiwara; Akihiro
Liu; Jihong |
Sakai-shi
Sakai-shi
Sakai-shi
Sakai-shi
Sakai-shi
Sakai-shi |
|
JP
JP
JP
JP
JP
JP |
|
|
Assignee: |
Daikin Industries, Ltd.
Osaka-shi, Osaka
JP
|
Family ID: |
45893004 |
Appl. No.: |
13/822206 |
Filed: |
September 27, 2011 |
PCT Filed: |
September 27, 2011 |
PCT NO: |
PCT/JP2011/072084 |
371 Date: |
March 11, 2013 |
Current U.S.
Class: |
165/151 ;
165/165 |
Current CPC
Class: |
F28F 1/022 20130101;
F28D 1/05333 20130101; F28F 3/086 20130101; B23K 1/203 20130101;
B23K 2101/14 20180801; F28D 1/05383 20130101; F28F 9/002 20130101;
F28F 9/0224 20130101; B23K 1/0012 20130101; F28F 9/0243 20130101;
B23K 2103/10 20180801; F28F 9/0278 20130101; F28F 2275/122
20130101; F28D 2021/0068 20130101 |
Class at
Publication: |
165/151 ;
165/165 |
International
Class: |
F28D 1/053 20060101
F28D001/053; F28F 9/00 20060101 F28F009/00; F28F 3/08 20060101
F28F003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2010 |
JP |
2010-219598 |
Aug 3, 2011 |
JP |
2011-170554 |
Claims
1. A heat exchanger comprising: a pair of headers extending in an
up-and-down direction, the pair of headers being configured to
carry a refrigerant flow therein; and plural flat tubes connected
to the headers at different height positions, the plural flat tubes
extending along a direction intersecting a longitudinal direction
of the headers, each of the headers including a first member having
a main flow path extending in the up-and-down direction and
configured to carry the refrigerant flow therein, and refrigerant
connection flow paths extending from the main flow path to an end
surface in the direction intersecting the longitudinal direction in
order to circulate the refrigerant flow between the main flow path
and plural refrigerant flow paths formed in the flat tubes, and a
flat tube holding member with end portions of the flat tubes
adhered thereto, the flat tube holding member holding the flat
tubes, and intermediate flow paths interconnecting the refrigerant
connection flow paths and the plural refrigerant flow paths in the
flat tubes, the intermediate flow paths being formed in at least
one of the headers and the flat tubes.
2. The heat exchanger according to claim 1, wherein a width of the
intermediate flow paths is no more than a width of the flat
tubes.
3. The heat exchanger according to claim 1, wherein each of the
headers further includes a second member sandwiched between the
first member and the flat tube holding member, and in a case where
the intermediate flow paths are at least partially formed in the
headers, the intermediate flow paths are at least partially formed
in the second member.
4. The heat exchanger according to claim 1, wherein in a case where
L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid two-phase state flowing through the main flow path, x is
an inlet quality, the inlet quality being a ratio of a mass flow
rate of the refrigerant in a gas-phase state with respect to a
total mass flow rate of the refrigerant in a gas-liquid two-phase
state inside an inlet header of the pair of headers, the
refrigerant flows from outside into the inlet header, .rho..sub.G
is a density of the refrigerant in a gas-phase state flowing
through the main flow path, D is a distance between the uppermost
flat tube and a lowermost flat tube, and C.sub.1 and C.sub.2 are
constants, a relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1
2 D 0.5 .ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00006## holds
true, and C.sub.1=0.16 and C.sub.2=1.5.
5. The heat exchanger according to claim 1, wherein in a case where
L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid two-phase state flowing through the main flow path, x is
an inlet quality, the inlet quality being a ratio of a mass flow
rate of the refrigerant in a gas-phase state with respect to a
total mass flow rate of the refrigerant in a gas-liquid two-phase
state inside an inlet header of the pair of headers, the
refrigerant flows from outside into the inlet header, .rho..sub.G
is a density of the refrigerant in a gas-phase state flowing
through the main flow path, D is a distance between the uppermost
flat tube and a lowermost flat tube, and C.sub.1 and C.sub.2 are
constants, a relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1
2 D 0.5 .ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00007## holds
true, and C.sub.1=0.24 and C.sub.2=1.1.
6. The heat exchanger according to claim 3, further comprising a
securing member sandwiched between the flat tube holding member and
the second member, the securing member securing the end portions of
the plural flat tubes together with the flat tube holding
member.
7. The heat exchanger according to claim 3, wherein the second
member has a flat panel shape.
8. The heat exchanger according to claim 3, wherein the flat tube
holding member covers the second member, and both ends of the flat
tube holding member are in contact with and brazed to the first
member.
9. The heat exchanger according to claim 1, wherein plural holes
are formed in the that tube holding member.
10. The heat exchanger according to claim 1, wherein a length in a
direction orthogonal to a longitudinal direction of the first
member, of a main flow path forming portion forming the main flow
path, is smaller than a width of the flat tubes.
11. The heat exchanger according to claim 2, wherein each of the
headers further includes a second member sandwiched between the
first member and the flat tube holding member, and in a case where
the intermediate flow paths are at least partially formed in the
headers, the intermediate flow paths are at least partially formed
in the second member.
12. The heat exchanger according to claim 2, wherein in a case
where L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid two-phase state flowing through the main flow path, x is
an inlet quality, the inlet quality being a ratio of a mass flow
rate of the refrigerant in a gas-phase state with respect to a
total mass flow rate of the refrigerant in a gas-liquid two-phase
state inside an inlet header of the pair of headers, the
refrigerant flows from outside into the inlet header, .rho..sub.G
is a density of the refrigerant in a gas-phase state flowing
through the main flow path, D is a distance between the uppermost
flat tube and a lowermost flat tube, and C.sub.1 and C.sub.2 are
constants, a relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1
2 D 0.5 .ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00008## holds
true, and C.sub.1=0.16 and C.sub.2=1.5.
13. The heat exchanger according to claim 2, wherein in a case
where L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid-phase state flowing through the main flow path, x is an
inlet quality, the inlet quality being a ratio of a mass flow rate
of the refrigerant in a gas-phase state with respect to a total
mass flow rate of the refrigerant in a gas-liquid two-phase state
inside an inlet header of the pair of headers, the refrigerant
flows from outside into the inlet header, .rho..sub.G is a density
of the refrigerant in a gas-phase state flowing through the main
flow path, D is a distance between the uppermost flat tube and a
lowermost flat tube, and C.sub.1 and C.sub.2 are constants, a
relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1 2 D 0.5
.ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00009## holds true, and
C.sub.1=0.24 and C.sub.2=1.1.
14. The heat exchanger according to claim 3, wherein in a case
where L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid two-phase state flowing through the main flow path, x is
an inlet quality, the inlet quality being a ratio of a mass flow
rate of the refrigerant in a gas-phase state with respect to a
total mass flow rate of the refrigerant in a gas-liquid two-phase
state inside an inlet header of the pair of headers, the
refrigerant flows from outside into the inlet header, .rho..sub.G
is a density of the refrigerant in a gas-phase state flowing
through the main flow path, D is a distance between the uppermost
flat tube and a lowermost flat tube, and C.sub.1 and C.sub.2 are
constants, a relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1
2 D 0.5 .ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00010## holds
true, and C.sub.1=0.16 and C.sub.2=1.5.
15. The heat exchanger according to claim 3, wherein in a case
where L1 is a length in a direction orthogonal to a longitudinal
direction of the first member of a main flow path forming portion
forming the main flow path, .pi. is pi, g is a gravitational
acceleration, m is a circulating volume of refrigerant in a
gas-liquid two-phase state flowing through the main flow path, x is
an inlet quality, the inlet quality being a ratio of a mass flow
rate of the refrigerant in a gas-phase state with respect to a
total mass flow rate of the refrigerant in a gas-liquid two-phase
state inside an inlet header of the pair of headers, the
refrigerant flows from outside into the inlet header, .rho..sub.G
is a density of the refrigerant in a gas-phase state flowing
through the main flow path, D is a distance between the uppermost
flat tube and a lowermost flat tube, and C.sub.1 and C.sub.2 are
constants, a relationship 4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1
2 D 0.5 .ltoreq. 4 C 1 .pi. m x .rho. G g 0.5 ##EQU00011## holds
true, and C.sub.1=0.24 and C.sub.2=1.1.
16. The heat exchanger according to claim 6, wherein the second
member and the securing member have flat panel shapes.
17. The heat exchanger according to claim 6, wherein the flat tube
holding member covers one of the second member and the second
member and the securing member from outside, and both ends of the
flat tube holding member are in contact with and brazed to the
first member.
18. The heat exchanger according to claim 7, wherein the flat tube
holding member covers one of the second member and the second
member and the securing member from outside, and both ends of the
flat tube holding member are in contact with and brazed to the
first member.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat exchanger.
BACKGROUND ART
[0002] Conventionally, there has been proposed a layered heat
exchanger which, like the one described in patent citation 1 (JP-A
No. 2006-284133), is equipped with headers that extend in a
vertical direction and plural flat tubes that extend in a direction
orthogonal to the length of the headers and are inserted into the
headers, with the heat exchanger performing heat exchange between
refrigerant flowing through plural holes formed in the flat tubes
and air flowing outside the flat tubes in a width direction
(transverse direction) of the flat tubes.
SUMMARY OF INVENTION
Technical Problem
[0003] In a heat exchanger like the one described in patent
citation 1 (JP-A No. 2006-284133), improving the pressure-resistant
strength is required in a case where, for example, high-pressure
refrigerant (e.g., CO.sub.2 refrigerant) flows through it. As a
measure for improving the pressure-resistant strength of the
headers, reducing the diameter of the headers themselves is
conceivable. However, when the diameter of the headers themselves
is reduced, the width of the flat tubes is reduced in accompaniment
therewith, so there is concern that this will have an impact on the
performance of the heat exchanger. On the other hand, when the
diameter of the headers is designed to match the width of the flat
tubes, there is concern that the diameter of the headers will be
unable to be reduced, which is not preferred from the standpoint of
improving the pressure-resistant strength.
[0004] Further, in a heat exchanger of this configuration in which
the flat tubes are inserted into the inside space of the headers
through which the refrigerant mainly travels, there is concern that
the pressure loss of the refrigerant will occur inside the
headers.
[0005] Thus, the object of the present invention is to provide a
heat exchanger that can achieve both improving the
pressure-resistant strength of the headers and suppressing the
pressure loss of the refrigerant.
Solution to Problem
[0006] A heat exchanger pertaining to a first aspect of the present
invention is equipped with a pair of headers and plural flat tubes.
The headers extend in an up-and-down direction and refrigerant
flows inside them. The plural flat tubes extend in a direction
intersecting a longitudinal direction of the headers and are
connected to the headers at different height positions. Each of the
headers has a first member and a flat tube holding member. The
first member has formed therein a main flow path and refrigerant
connection flow paths. The main flow path extends in the
up-and-down direction and refrigerant flows through it. The
refrigerant connection flow paths extend from the main flow path to
an end surface in the direction in which the flat tubes are
positioned in order to circulate the refrigerant between the main
flow path and plural refrigerant flow paths formed in the flat
tubes. End portions of the flat tubes are adhered to the flat tube
holding member, and the flat tube holding member holds the flat
tubes. Additionally, intermediate flow paths that interconnect the
refrigerant connection flow paths and the plural refrigerant flow
paths in the flat tubes are formed in the headers and/or the flat
tubes.
[0007] Here, for example, when a heat exchanger is given a
configuration in which the flat tubes are inserted into the
headers, there is concern that the pressure loss of the refrigerant
will occur.
[0008] Thus, in the heat exchanger pertaining to the first aspect
of the present invention, the flat tubes are held using the flat
tube holding member that is separate from the first member having
formed therein the main flow path through which the refrigerant
flows. That is, a configuration in which the flat tubes are not
inserted into the main flow path is employed. Because of this, the
pressure loss of the refrigerant can be suppressed. Because of the
refrigerant connection flow paths and the intermediate flow paths
that are separate from the main flow path, the refrigerant flowing
through the main flow path flows to the refrigerant flow paths in
the flat tubes.
[0009] Further, when this configuration is employed, the diameter
of the main flow path does not have to match the width of the flat
tubes because the flat tubes do not have to be inserted into the
main flow path. Therefore, the diameter of the section of the main
flow path through which the refrigerant travels can be reduced and
the pressure-resistant strength can be improved.
[0010] A heat exchanger pertaining to a second aspect of the
present invention is the heat exchanger pertaining to the first
aspect of the present invention, wherein the width of the
intermediate flow paths is equal to or less than the width of the
flat tubes.
[0011] In the heat exchanger pertaining to the second aspect of the
present invention, the width of the intermediate flow paths is
equal to or less than the width of the flat tubes, so the
longitudinal direction end surfaces of the flat tubes come into
contact with the peripheries of intermediate flow path forming
portions forming the intermediate flow paths. Because of this, the
positioning of the flat tubes can be performed easily.
[0012] A heat exchanger pertaining to a third aspect of the present
invention is the heat exchanger pertaining to the first aspect or
the second aspect of the present invention, wherein each of the
headers further has a second member that is sandwiched between the
first member and the flat tube holding member. Additionally, in a
case where the intermediate flow paths are formed in the headers
and the flat tubes or the headers, the intermediate flow paths are
formed in the second member.
[0013] In the heat exchanger pertaining to the third aspect of the
present invention, both improving the pressure-resistant strength
of the headers and suppressing the pressure loss of the refrigerant
can be achieved.
[0014] A heat exchanger pertaining to a fourth aspect of the
present invention is the heat exchanger pertaining to any of the
first aspect to the third aspect of the present invention, wherein
in a case where L1 is the length, in a direction orthogonal to a
longitudinal direction of the first member, of a main flow path
forming portion forming the main flow path, .pi. is pi, g is
gravitational acceleration, m is the circulating volume of the
refrigerant in a gas-liquid two-phase state flowing through the
main flow path, x is inlet quality, which is the ratio of the mass
flow rate of the refrigerant in a gas-phase state with respect to
the total mass flow rate of the refrigerant in a gas-liquid
two-phase state inside an inlet header among the pair of headers
into which the refrigerant flows from outside, .rho..sub.G is the
density of the refrigerant in a gas-phase state flowing through the
main flow path, D is the distance between the uppermost flat tube
and the lowermost flat tube, and C.sub.1 and C.sub.2 are constants,
the relationship of
4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1 2 D 0.5 .ltoreq. 4 C 1
.pi. m x .rho. G g 0.5 ##EQU00001##
holds true. Additionally, C.sub.1=0.16 and C.sub.2=1.5.
[0015] In the heat exchanger pertaining to the fourth aspect of the
present invention, when L1 is decided in such a way that the
above-described relationship holds true, it is easy to equally
divide the refrigerant flowing through the main flow path to the
refrigerant connection flow paths. That is, it becomes easier for
the refrigerant flowing through the main flow path to flow equally
to the refrigerant flow paths in the flat tubes connected to the
refrigerant connection flow paths.
[0016] A heat exchanger pertaining to a fifth aspect of the present
invention is the heat exchanger pertaining to any of the first
aspect to the third aspect of the present invention, wherein in a
case where L1 is the length, in a direction orthogonal to a
longitudinal direction of the first member, of a main flow path
forming portion forming the main flow path, .pi. is pi, g is
gravitational acceleration, m is the circulating volume of the
refrigerant in a gas-liquid two-phase state flowing through the
main flow path, x is inlet quality, which is the ratio of the mass
flow rate of the refrigerant in a gas-phase state with respect to
the total mass flow rate of the refrigerant in a gas-liquid
two-phase state inside an inlet header among the pair of headers
into which the refrigerant flows from outside, .rho..sub.G is the
density of the refrigerant in a gas-phase state flowing through the
main flow path, D is the distance between the uppermost flat tube
and the lowermost flat tube, and C.sub.1 and C.sub.2 are constants,
the relationship of
4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1 2 D 0.5 .ltoreq. 4 C 1
.pi. m x .rho. G g 0.5 ##EQU00002##
holds true. Additionally, C.sub.1=0.24 and C.sub.2=1.1.
[0017] In the heat exchanger pertaining to the fifth aspect of the
present invention, when L1 is decided in such a way that the
above-described relationship holds true, it is easy to more equally
divide the refrigerant flowing through the main flow path to the
refrigerant connection flow paths. That is, it becomes easier for
the refrigerant flowing through the main flow path to flow more
equally to the refrigerant flow paths in the flat tubes connected
to the refrigerant connection flow paths.
[0018] A heat exchanger pertaining to a sixth aspect of the present
invention is the heat exchanger pertaining to the third aspect of
the present invention and is further equipped with a securing
member. The securing member is sandwiched between the flat tube
holding member and the second member and secures the end portions
of the plural flat tubes together with the flat tube holding
member.
[0019] In the heat exchanger pertaining to the sixth aspect of the
present invention, the flat tubes can be more stably secured.
[0020] A heat exchanger pertaining to a seventh aspect of the
present invention is the heat exchanger pertaining to the third
aspect or the sixth aspect of the present invention, wherein the
second member and the securing member have flat panel shapes.
[0021] In the heat exchanger pertaining to the seventh aspect of
the present invention, for example, in the case of securing the
flat tubes by forming holes in the securing member and putting the
flat tubes into those holes, construction is easy to execute
because the securing member with a flat panel shape enables that
the holes can be formed all at once in the securing member.
Further, likewise in the case of forming the intermediate flow
paths in the second member also, construction is easy to execute
because the holes can be formed all at once in the second
member.
[0022] A heat exchanger pertaining to an eighth aspect of the
present invention is the heat exchanger pertaining to any of the
third aspect, the sixth aspect, and the seventh aspect of the
present invention, wherein the flat tube holding member covers the
second member or the second member and the securing member from
outside, and both ends of the flat tube holding member are in
contact with and brazed to the first member.
[0023] In the heat exchanger pertaining to the eighth aspect of the
present invention, the second member and the securing member can be
easily secured by the flat tube holding member.
[0024] A heat exchanger pertaining to a ninth aspect of the present
invention is the heat exchanger pertaining to any of the first
aspect to the eighth aspect of the present invention, wherein
plural holes are formed in the flat tube holding member.
[0025] Here, for example, in the case of connecting the flat tube
holding member and the flat tubes and connecting the flat tube
holding member and the second member, a flux is applied.
Thereafter, in the case of connecting these by brazing or the like,
it is assumed that the flux will volatilize.
[0026] Thus, in the heat exchanger pertaining to the ninth aspect
of the present invention, the plural holes are formed in the flat
tube holding member. Because of this, volatilized gas can be
removed. Consequently, airtightness between connected members can
be ensured.
[0027] A heat exchanger pertaining to a tenth aspect of the present
invention is the heat exchanger pertaining to any of the first
aspect to the ninth aspect of the present invention, wherein the
length, in a direction orthogonal to a longitudinal direction of
the first member, of a main flow path forming portion forming the
main flow path is smaller than the width of the flat tubes.
[0028] In the heat exchanger pertaining to the tenth aspect of the
present invention, the length, in the direction orthogonal to the
longitudinal direction of the first member, of the main flow path
forming portion forming the main flow path can be made smaller than
the width of the flat tubes because the flat tubes do not have to
be inserted into the main flow path.
Advantageous Effects of Invention
[0029] In the heat exchanger pertaining to the first aspect of the
present invention, both improving the pressure-resistant strength
of the headers and suppressing the pressure loss of the refrigerant
can be achieved.
[0030] In the heat exchanger pertaining to the second aspect of the
present invention, the positioning of the flat tubes can be
performed easily.
[0031] In the heat exchanger pertaining to the third aspect of the
present invention, both improving the pressure-resistant strength
of the headers and suppressing the pressure loss of the refrigerant
can be achieved.
[0032] In the heat exchanger pertaining to the fourth aspect of the
present invention, it becomes easier for the refrigerant flowing
through the main flow path to flow equally to the refrigerant flow
paths in the flat tubes.
[0033] In the heat exchanger pertaining to the fifth aspect of the
present invention, it becomes easier for the refrigerant flowing
through the main flow path to flow more equally to the refrigerant
flow paths in the flat tubes.
[0034] In the heat exchanger pertaining to the sixth aspect of the
present invention, the flat tubes can be more stably secured.
[0035] In the heat exchanger pertaining to the seventh aspect of
the present invention, construction is easy to execute.
[0036] In the heat exchanger pertaining to the eighth aspect of the
present invention, the second member and the securing member can be
easily secured by the flat tube holding member.
[0037] In the heat exchanger pertaining to the ninth aspect of the
present invention, airtightness between connected members can be
ensured.
[0038] In the heat exchanger pertaining to the tenth aspect of the
present invention, the length, in the direction orthogonal to the
longitudinal direction of the first member, of the main flow path
forming portion forming the main flow path can be made smaller than
the width of the flat tubes because the flat tubes do not have to
be inserted into the main flow path.
BRIEF DESCRIPTION OF DRAWINGS
[0039] FIG. 1 is a schematic configuration diagram of a heat
exchanger (details regarding headers are not shown).
[0040] FIG. 2 is an enlarged view of section II of FIG. 1.
[0041] FIG. 3 is a plan view of a first header and flat tubes in a
case where an upper end member has been removed.
[0042] FIG. 4 is a longitudinal cross-sectional view in a case
where the first header and the flat tubes in a case where the upper
end member and a lower end member have been removed are cut along
line IV-IV shown in FIG. 3.
[0043] FIG. 5 is a longitudinal cross-sectional view in a case
where a first member is cut along line V-V shown in FIG. 3.
[0044] FIG. 6 is a schematic perspective view of part of the first
member.
[0045] FIG. 7 is a longitudinal cross-sectional view in which a
flat tube holding member is cut along a cutting line that is
parallel, in the longitudinal direction of the flat tube holding
member, to line V-V shown in FIG. 3.
[0046] FIG. 8 is a longitudinal cross-sectional view in which a
second member is cut along a cutting line that is parallel, in the
longitudinal direction of the second member, to line V-V shown in
FIG. 3.
[0047] FIG. 9 is a graph showing the relationship between constants
C.sub.1 and C.sub.2 and flow dividing ability.
[0048] FIG. 10 is a longitudinal cross-sectional view showing the
flat tube holding member pertaining to modification 1A.
[0049] FIG. 11 is a plan view, pertaining to modification 1C, of
the first header and the flat tube in a case where the upper end
member has been removed.
[0050] FIG. 12 is a side view, pertaining to modification 1C, of
the first member as seen from the side of the flat tubes.
[0051] FIG. 13 is a plan view, pertaining to modification 1D, of
the first header and the flat tubes in a case where the upper end
member has been removed.
[0052] FIG. 14 is a side view, pertaining to modification 1D, of
the first member as seen from the side of the flat tubes.
[0053] FIG. 15 is a plan view, pertaining to modification 1E, of
the first header and the flat tubes in a case where the upper end
member has been removed.
[0054] FIG. 16 is a plan view, pertaining to modification 1F, of
the first header and the flat tubes in a case where the upper end
member has been removed.
[0055] FIG. 17 is a plan view, pertaining to modification 1 G, of
the first header and the flat tubes in a case where the upper end
member has been removed.
[0056] FIG. 18 is a plan view, pertaining to a second embodiment,
of the first header and the flat tubes in a case where the upper
end member has been removed.
[0057] FIG. 19 is a longitudinal cross-sectional view, pertaining
to the second embodiment, in a case where the first header and the
flat tubes in a case where the upper end member and the lower end
member have been removed are cut along line XIX-XIX shown in FIG.
18.
[0058] FIG. 20 is a longitudinal cross-sectional view in a case
where a securing member is cut along line XX-XX shown in FIG.
18.
DESCRIPTION OF EMBODIMENTS
[0059] A heat exchanger 1 pertaining to embodiments of the present
invention will be described below with reference to the
drawings.
First Embodiment
(1) Configuration of Heat Exchanger 1
[0060] FIG. 1 is a schematic configuration diagram of the heat
exchanger 1. FIG. 2 is an enlarged view of section II of FIG.
1.
[0061] The heat exchanger 1 is a heat exchanger that uses air as a
cooling source or a heating source to condense or evaporate
refrigerant, and the heat exchanger 1 is, for example, employed as
a heat exchanger that configures a refrigerant circuit of a vapor
compression refrigeration apparatus. Here, carbon dioxide
refrigerant is used as the refrigerant circulating through the
refrigerant circuit.
[0062] As shown in FIG. 1 and FIG. 2, the heat exchanger 1 mainly
has plural flat tubes 11a to 11f, heat transfer fins 12, and a pair
of headers 13 and 14. These will be described below.
(1-1) Flat Tubes 11a to 11f
[0063] Each of the flat tubes 11a to 11f is formed by extruding a
metal member made of aluminum or an aluminum alloy, for example.
The flat tubes 11a to 11f extend long in a direction intersecting
(specifically, a direction orthogonal to) the longitudinal
direction of the later-described headers 13 and 14, and as shown in
FIG. 2, the flat tubes 11a to 11f are disposed a predetermined
interval apart from each other in the up-and-down direction in a
state in which long and wide planar portions 111 face the
up-and-down direction (the longitudinal direction of the headers 13
and 14). Plural refrigerant flow paths 112 are formed inside each
of the flat tubes 11a to 11f, and the refrigerant flows in these
refrigerant flow paths 112. Specifically, the plural refrigerant
flow paths 112 are formed side by side in the transverse direction
of the flat tubes 11a to 11f in such a way as to penetrate the flat
tubes 11a to 11f in the longitudinal direction of the flat tubes
11a to 11f.
[0064] Here, six flat tubes are disposed, but the number of the
flat tubes is not limited to this.
(1-2) Heat Transfer Fins 12
[0065] The heat transfer fins 12 are corrugated fins configured
from metal members made of aluminum or an aluminum alloy, and
formed as a result of panel-like members being folded in corrugated
shapes in their longitudinal direction. The heat transfer fins 12
are disposed in spaces sandwiched by the flat tubes 11a to 11f. The
mountain fold sections on the upper ends of the heat transfer fins
12 are joined by brazing or the like to the undersurfaces of the
planar portions 111, and the valley fold sections on the lower ends
of the heat transfer fins 12 are joined by brazing or the like to
the upper portions of the planar portions 111. Further, plural
cut-and-raised portions 12a for improving heat exchange efficiency
are cut and raised in louver shapes in the heat transfer fins 12.
The cut-and-raised portions 12a are formed in such a way that their
directions of inclination with respect to the air flow direction
are opposite between the sections on the upstream side and the
sections on the downstream side in the air flow direction (the flow
direction of air flowing in the transverse direction (width
direction) of the flat tubes 11a to 11f).
(1-3) Headers 13 and 14
[0066] As shown in FIG. 1, the headers 13 and 14 are members that
are spaced apart from each other and extend in the up-and-down
direction (specifically, the vertical direction). Flat tube-use
holes (included among these are later-described flat tube-use holes
132a to 132f (see FIG. 4) in the first header 13) for connecting
the plural flat tubes 11a to 11f to the headers 13 and 14 are
formed in the outer surfaces of the headers 13 and 14 at different
height positions (specifically, a predetermined interval apart from
each other) along the longitudinal direction of the headers 13 and
14. Additionally, both longitudinal direction end portions of each
of the flat tubes 11a to 11f extending in the direction orthogonal
to the longitudinal direction of the headers 13 and 14 are inserted
into these flat tube-use holes. The flat tube-use holes are formed
by stamping or the like.
[0067] The headers 13 and 14 have a support function of supporting
the flat tubes 11a to 11f, an inflow function of allowing the
refrigerant to flow into the flat tubes 11a to 11f (specifically,
the plural refrigerant flow paths 112 formed in the flat tubes 11a
to 11f), and a merge function of allowing the refrigerant flowing
out from the flat tubes 11a to 11f (specifically, the plural
refrigerant flow paths 112 formed in the flat tubes 11a to 11f) to
merge.
[0068] In the description below, for convenience of description,
the header on the left side in FIG. 1 will be called "the first
header 13" and the header on the right side in FIG. 1 will be
called "the second header 14". The configuration of the headers 13
and 14 is not limited to the configuration shown in FIG. 1, and a
variety of configurations can be applied.
[0069] The first header 13 is a cylindrical member that has an
outer peripheral portion in which an opening 130 is formed and an
upper end and lower end that are closed and extends in the
up-and-down direction. The opening 130 has the function of allowing
the refrigerant to flow into the first header 13 or allowing the
refrigerant to flow outside from the first header 13. Specifically,
the opening 130 becomes an inlet for the refrigerant in a case
where the heat exchanger 1 functions as an evaporator of the
refrigerant and becomes an outlet for the refrigerant in a case
where the heat exchanger 1 functions as a condenser of the
refrigerant.
[0070] The second header 14 is a tubular member that has an outer
peripheral portion in which an opening 140 is formed and an upper
end and lower end that are closed and extends in the up-and-down
direction. The opening 140 has the function of allowing the
refrigerant to flow into the second header 14 or allowing the
refrigerant to flow outside from the second header 14.
Specifically, the opening 140 becomes an inlet for the refrigerant
in a case where the heat exchanger 1 functions as a condenser of
the refrigerant and becomes an outlet for the refrigerant in a case
where the heat exchanger 1 functions as an evaporator of the
refrigerant.
[0071] The opening 130 and the opening 140 are formed by stamping
or the like. Further, pipes 151 and 152 through which the
refrigerant flows are connected to the opening 130 and the opening
140.
(2) Regarding the Specific Configuration of the Headers 13 and
14
[0072] The first header 13 and the second header 14 have the same
configuration. Therefore, in the description below, only the
configuration of the first header 13 will be described and
description of the configuration of the second header 14 will be
omitted.
[0073] FIG. 3 is a plan view of the first header 13 and the flat
tubes in a case where an upper end member has been removed. FIG. 4
is a longitudinal cross-sectional view in which the first header 13
and the flat tubes 11a to 11f in a case where the upper end member
and a lower end member have been removed are cut along line IV-IV
shown in FIG. 3. FIG. 5 is a longitudinal cross-sectional view in a
case where a first member 131 is cut along line V-V shown in FIG.
3. FIG. 6 is a schematic perspective view of part of the first
member 131. FIG. 7 is a longitudinal cross-sectional view in which
a flat tube holding member 132 is cut along a cutting line that is
parallel, in the longitudinal direction of the flat tube holding
member 132, to line V-V shown in FIG. 3. FIG. 8 is a longitudinal
cross-sectional view in which a second member 133 is cut along a
cutting line that is parallel, in the longitudinal direction of the
second member 133, to line V-V shown in FIG. 3.
[0074] As shown in FIG. 3 to FIG. 8, the first header 13 mainly has
a first member 131, a flat tube holding member 132, and a second
member 133. These members will be specifically described below.
(2-1) First Member 131
[0075] The first member 131 is a member that extends in the
vertical direction and is configured from a metal member such as
clad metal comprising an aluminum alloy with a low melting point
bonded to the surface of another aluminum alloy serving as a core.
As shown in FIG. 3 and FIG. 6, the first member 131 has a shape in
which a cylinder and a cuboid are combined. The cross section of
the first member 131 orthogonal to the longitudinal direction of
the first member 131 has a ".OMEGA." shape (a shape in which about
3/4 of a circular arc and end portions of that circular arc are
joined by a straight line and in which a quadrilateral is connected
to that straight line section).
[0076] Specifically, the first member 131 has a first portion 331a,
which extends in the vertical direction and has a transverse cross
section having a shape in which about 3/4 of a circular arc and end
portions of that circular arc are joined by a straight line, and a
second portion 331b, which extends in the vertical direction and
has a flat panel shape that is long and narrow in the width
direction.
[0077] As shown in FIG. 3, FIG. 4, and FIG. 6, a refrigerant main
flow path 131a that penetrates the first member 131 (specifically,
the first portion 331a) in the up-and-down direction (specifically,
the vertical direction) and through which the refrigerant mainly
flows is formed in the first member 131 (specifically, the first
portion 331a). The cross section (transverse cross section) of the
refrigerant main flow path 131a orthogonal to the longitudinal
direction of the refrigerant main flow path 131a has a circular
shape. A length L1 (see FIG. 3), in a direction orthogonal to the
longitudinal direction of the first member 131, of a refrigerant
main flow path forming portion 13a (see FIG. 3 and FIG. 4) forming
the refrigerant main flow path 131a is 10 mm. Further, the
thickness of the first member 131 (the distance between the inner
surface of the refrigerant main flow path forming portion 13a and
the outer surface of the first portion 331a) is preferably 3 mm to
6 mm.
[0078] Further, refrigerant connection flow paths 231a to 231f that
are in communication with refrigerant main flow path 131a, extend
to an end surface in the direction in which the flat tubes 11a to
11f are positioned (the direction orthogonal to the longitudinal
direction of the first member 131), and penetrate the first member
131 are formed in the first member 131 in order to circulate the
refrigerant with the plural refrigerant flow paths 112 formed in
the flat tubes 11a to 11f. The refrigerant connection flow paths
231a to 231f are formed a predetermined interval apart from each
other along the longitudinal direction of the first member 131. As
shown in FIG. 6, the cross sections of the refrigerant connection
flow paths 231a to 231f cut in the longitudinal direction of the
first member 131 (the vertical direction) have circular shapes. The
refrigerant connection flow paths 231a to 231f are formed by
drilling. A height H1 of the refrigerant connection flow paths 231a
to 231f (specifically, refrigerant connection flow path forming
portions 233a to 233f (see FIG. 5) forming the refrigerant
connection flow paths 231a to 231f) is larger than the thickness of
the flat tubes 11a to 11f.
(2-2) Flat Tube Holding Member 132
[0079] The flat tube holding member 132 is a member to which the
end portions of the flat tubes 11a to 11f are connected (adhered)
and which holds the flat tubes 11a to 11f. The flat tube holding
member 132 is a member that is configured from a metal member such
as clad metal and extends in the vertical direction. As shown in
FIG. 3, in a regularly assembled state, the transverse cross
section of the flat tube holding member 132 (the cross section
orthogonal to the longitudinal direction of the flat tube holding
member 132) has a "U" shape whose end portions are bent inward.
[0080] In a regularly assembled state, the flat tube holding member
132 is bent inward in such a way as to cover both width direction
end portions of the second portion 331b of the first member 131.
Additionally, the inwardly bent end portions of the flat tube
holding member 132 are positioned in recessed portion spaces S
formed by the first portion 331a and the second portion 331b of the
first member 131.
[0081] As shown in FIG. 3 and FIG. 4, plural flat tube-use holes
132a to 132f for inserting the plural flat tubes 11a to 11f and
holding the flat tubes 11a to 11f are formed in the flat tube
holding member 132. The flat tube-use holes 132a to 132f are formed
by stamping or the like. The flat tube-use holes 132a to 132f are
formed a predetermined interval apart from each other along the
longitudinal direction of the flat tube holding member 132. The
height of the flat tube-use holes 132a to 132f is formed a little
smaller than the thickness of the flat tubes 11a to 11f. Therefore,
by inserting the flat tubes 11a to 11f into the flat tube-use holes
132a to 132f, the flat tubes 11a to 11f are held.
[0082] In a state in which the flat tubes 11a to 11f are normally
attached to the flat tube holding member 132, the end surfaces of
the flat tubes 11a to 11f on the inserted sides and the end surface
of the flat tube holding member 132 on the first member 131 side
are positioned in substantially the same position.
[0083] FIG. 7 shows a longitudinal cross-sectional view of the flat
tube holding member 132 in a state in which the flat tubes 11a to
11f are normally attached to the flat tube holding member 132.
(2-3) Second Member 133
[0084] As shown in FIG. 3 and FIG. 4, the second member 133 is a
member having one end surface adhered to the first member 131
(specifically, the end surface of the second portion 331b) and
another end surface adhered to the end surface of the flat tube
holding member 132. That is, the second member 133 is sandwiched
between the first member 131 and the flat tube holding member
132.
[0085] The second member 133 is configured from a metal member such
as clad metal (clad metal with a higher melting point than that of
other members is used for the clad metal forming the second member
133) and has a long and narrow flat panel shape extending in the
vertical direction. The transverse cross section of the second
member 133 has a quadrilateral shape.
[0086] As shown in FIG. 4 and FIG. 8, intermediate flow paths 133a
to 133f that penetrate the second member 133 in a direction
orthogonal to the longitudinal direction of the second member 133
are formed in the second member 133. As shown in FIG. 8, the
intermediate flow paths 133a to 133f have longitudinal cross
sections having transversely long and narrow oval shapes. As shown
in FIG. 4 and FIG. 8, the plural intermediate flow paths 133a to
133f are formed a predetermined interval apart from each other
along the longitudinal direction of the second member 133.
Additionally, the plural intermediate flow paths 133a to 133f are
in communication with the refrigerant connection flow paths 231a to
231f formed in the first member 131 and the plural refrigerant flow
paths 112 formed in the flat tubes 11a to 11f.
[0087] That is, the second member 133 has the function of enabling
the circulation of the refrigerant between the first member 131
having formed therein a flow path (specifically, the refrigerant
main flow path 131a) through which the refrigerant mainly travels
and the plural refrigerant flow paths 112 formed in the flat tubes
11a to 11f. Specifically, the second member 133 has the function of
enabling the circulation of the refrigerant between the plural
refrigerant flow paths 112 formed in the flat tubes 11a to 11f and
the refrigerant main flow path 131a and refrigerant connection flow
paths 231a to 231f formed in the first member.
[0088] The height of the intermediate flow paths 133a to 133f
(specifically, the height of intermediate flow path forming
portions 134a to 134f forming the intermediate flow paths 133a to
133f) is larger than the thickness of the flat tubes 11a to 11f and
is larger than the height H1 of the refrigerant connection flow
paths 231a to 231f (specifically, the refrigerant connection flow
path forming portions 233a to 233f). This is to facilitate the
circulation of the refrigerant between the first header 13 and the
flat tubes 11a to 11f.
[0089] Further, a width W3 of the intermediate flow paths 133a to
133f (specifically, a width W3 of the intermediate flow path
forming portions 134a to 134f forming the intermediate flow paths
133a to 133f) is equal to or less than a width W22 of the flat
tubes 11a to 11f (see FIG. 7).
(3) Regarding Method of Manufacturing the Heat Exchanger 1
[0090] A method of manufacturing the heat exchanger 1 will be
described below. In the description below also, description of the
second header 14 will be omitted.
[0091] First, the first member 131 is formed. Specifically, a long
and narrow cylinder-shaped member having an open space
(specifically, the refrigerant main flow path 131a) inside is
formed by processing (e.g., extruding) clad metal comprising an
aluminum alloy with a low melting point bonded to the surface of
another aluminum alloy serving as a core. Then, holes
(specifically, the refrigerant connection flow paths 231a to 231f)
that penetrate the member with the cylindrical shape in a direction
orthogonal to the longitudinal direction of the member with the
cylindrical shape from the inside space are formed in the
cylinder-shaped member by drilling. The holes are formed a
predetermined interval apart from each other along the longitudinal
direction of the cylinder-shaped member. Because of this, the first
member 131 having formed therein the refrigerant main flow path
131a and the refrigerant connection flow paths 231a to 231f is
formed.
[0092] Next, the second member 133 is formed. Specifically, plural
holes (specifically, the intermediate flow paths 133a to 133f) are
formed in flat panel-shaped clad metal at a predetermined interval
apart from each other along the longitudinal direction of the flat
panel-shaped clad metal by stamping. Because of this, the second
member 133 having formed therein the intermediate flow paths 133a
to 133f is formed.
[0093] Next, holes (specifically, the flat tube-use holes 132a to
132f) for holding the flat tubes 11a to 11f are formed in flat
panel-shaped clad metal at a predetermined interval apart from each
other along the longitudinal direction of the flat panel-shaped
clad metal by stamping.
[0094] Next, the first member 131, the second member 133, the flat
panel-shaped clad metal having formed therein the holes for holding
the flat tubes 11a to 11f, and the flat tubes 11a to 11f are
assembled in such a way as to be positioned in this order.
[0095] Then, the flat panel-shaped clad metal is bent in such a way
as to cover the second member 133 from outside along the shape of
the second member 133, and both ends of the flat panel-shaped clad
metal are brought into contact with, in such a way as to cover from
outside, part of the first member 131 (specifically, the second
portion 331b) and positioned in the recessed portion spaces S.
Because of this, the flat tube holding member 132 whose transverse
cross section has a "U" shape is formed.
[0096] Then, the flat tubes 11a to 11f are inserted into the flat
tube-use holes 132a to 132f.
[0097] Then, these are joined together by brazing. Here, by using
clad metal for the flat tube holding member 132 and joining the
flat tube holding member 132 to the flat tubes 11a to 11f, leakage
of the refrigerant to the outside from the refrigerant flow paths
112 in the flat tubes 11a to 11f can be prevented.
[0098] The first member 131 is given a configuration in which its
upper and lower ends are closed by an upper end member and a lower
end member (not shown in the drawings) having the same
cross-sectional shape as that of the first member 131, and the
upper end member and the lower end member are joined to the first
member 131 by brazing.
[0099] Further, the second header 14 is joined to the other end
portions of the flat tubes 11a to 11f in the same way as the first
header 13. As described above, the heat exchanger 1 is
manufactured.
(4) Flows of the Refrigerant
[0100] The series of flows of the refrigerant in the heat exchanger
1 having the above configuration will be briefly described.
(4-1) Flow of the Refrigerant in a Case where the Heat Exchanger 1
Functions as an Evaporator
[0101] First, the refrigerant flowing toward the heat exchanger 1
from outside the first header 13 flows into the first header 13 via
the opening 130. Here, the first header 13 functions as an inlet
header into which the refrigerant flows from outside. The general
flow of the refrigerant is such that the refrigerant that has
flowed into the first header 13 travels through the refrigerant
main flow path 131a formed in the first member 131, is distributed
to the flat tubes 11f to 11a, and is substantially equally divided
to the refrigerant flow paths 112 formed in the flat tubes 11f to
11a.
[0102] More specifically, the refrigerant that has flowed into the
first header 13 travels through the refrigerant main flow path 131a
formed in the first member 131 and is substantially equally
distributed to the refrigerant connection flow paths 231f to 231a
formed in the first member 131. The refrigerant that has flowed
into the refrigerant connection flow paths 231f to 231a flows into
the intermediate flow paths 133f to 133a formed in the second
member 133. The refrigerant that has flowed into the intermediate
flow paths 133f to 133a is substantially equally divided to the
plural refrigerant flow paths 112 formed in the flat tubes 11f to
11a held in the flat tube holding member 132.
[0103] Then, the refrigerant that is equally divided to the
refrigerant flow paths 112 flows toward the second header 14. The
refrigerant that has merged inside the second header 14 flows out
to the outside of the heat exchanger 1 via the opening 140.
[0104] As described above, in a case where the heat exchanger 1
functions as an evaporator, the refrigerant flows through the
insides of the headers 13 and 14 from the lower space to the upper
space.
(4-2) Flow of the Refrigerant in a Case where the Heat Exchanger 1
Functions as a Condenser
[0105] In a case where the heat exchanger 1 functions as a
condenser, the refrigerant flowing toward the heat exchanger 1 from
outside the second header 14 flows into the second header 14 via
the opening 140. Here, the second header 14 functions as an inlet
header into which the refrigerant flows from outside.
[0106] Then, like the flow of the refrigerant in the case where the
heat exchanger 1 functions as an evaporator, the refrigerant that
has flowed into the second header 14 flows toward the first header
13. The refrigerant that has merged inside the first header 13
flows out to the outside of the heat exchanger 1 via the opening
130.
[0107] As described above, in a case where the heat exchanger 1
functions as a condenser, the refrigerant flows through the insides
of the headers 13 and 14 from the upper space to the lower
space.
[0108] Here, as shown in FIG. 3, a width W1 of the refrigerant
connection flow paths 231a to 231f (specifically, a width W1 of the
refrigerant connection flow path forming portions 233a to 233f) is
the minimum dimension necessary for the refrigerant to travel
through in order to enhance the pressure-resistant strength of the
first member 131. Therefore, the width W1 of the refrigerant
connection flow paths 231a to 231f (specifically, the refrigerant
connection flow path forming portions 233a to 233f) is smaller than
a width W2 (see FIG. 7) of the sections of the flat tubes 11a to
11f in which the refrigerant flow paths 112 are formed. Thus, here,
the width W3 of the intermediate flow paths 133a to 133f
(specifically, the intermediate flow path forming portions 134a to
134f forming the intermediate flow paths 133a to 133f) formed in
the second member 133 is equal to or greater than the width W2 of
the sections of the flat tubes 11a to 11f in which the refrigerant
flow paths 112 are formed. Because of this, the exchange of the
refrigerant between the first member 131 and the plural flat tubes
11a to 11f can be performed easily.
(5) Regarding the Refrigerant Main Flow Path 131a
[0109] The length L1 [m], in the direction orthogonal to the
longitudinal direction of the first member 131, of the refrigerant
main flow path forming portion 13a forming the refrigerant main
flow path 131a can be decided using equality 1 below.
4 C 2 .pi. m x .rho. G g 0.5 .ltoreq. L 1 2 D 0.5 .ltoreq. 4 C 1
.pi. m x .rho. G g 0.5 ( Equality 1 ) ##EQU00003##
[0110] Here, .pi. is pi. g is gravitational acceleration
[m/s.sup.2]. m is the circulating volume [kg/s] of the refrigerant
in a gas-liquid two-phase state flowing through the refrigerant
main flow path 131a. x is inlet quality, which is the ratio of the
mass flow rate of the refrigerant in a gas-phase state with respect
to the total mass flow rate of the refrigerant in a gas-liquid
two-phase state inside the first header 13 or the second header 14
functioning as the inlet header. .rho..sub.G is the density
[kg/m.sup.3] of the refrigerant in a gas-phase state flowing
through the refrigerant main flow path 131a and, in the present
embodiment, is a value decided by the evaporation temperature. D is
the distance [m] between the upper surface of the uppermost flat
tube 11a and the undersurface of the lowermost flat tube 11f (see
FIG. 4). C.sub.1 and C.sub.2 are constants.
[0111] From the above equality 1, it will be understood that the
length L1 is decided by the constants C.sub.1 and C.sub.2 and the
distance D. The distance D is a value unequivocally decided in
accordance with the type of the headers 13 and 14.
[0112] Here, the inventors of the present invention performed an
experiment and discovered the constants C.sub.1 and C.sub.2 with
which flow dividing ability becomes equal to or greater than a
predetermined ability (in the present embodiment, 90%). "Flow
dividing ability" is an ability indicating how equally the
refrigerant can be allowed to flow from the refrigerant main flow
path 131a to the refrigerant connection flow paths 231a to 231f and
therefore to the refrigerant flow paths 112 in the flat tubes 11a
to 11f; if the flow dividing ability is equal to or greater than
90%, it can be said that the flow dividing ability is high.
[0113] FIG. 9 is a graph showing the relationship between the
constants C.sub.1 and C.sub.2 and the flow dividing ability that is
the result of the experiment described above. The experiment that
led to the graph of FIG. 9 was performed under the conditions that
carbon dioxide refrigerant was used as the refrigerant, headers 13
and 14 in which D was 300 mm to 500 mm and L1 was 5 mm to 15 mm
were used, the evaporation temperature was 0.degree. C., and x was
0.2. The same results (that is, values of C.sub.1 and C.sub.2 with
which the flow dividing ability is high) are obtained even if the
experimental conditions (e.g., the evaporation temperature and the
value of x) are changed somewhat.
[0114] In this experiment, a value calculated from expression 2
below is used as a substitute value of the constants C.sub.1 and
C.sub.2 (U.sub.gs is gas speed).
U gs ( gD ) 0.5 ( Expression 2 ) ##EQU00004##
[0115] This is because the relationship of equality 4 below can be
derived when equality 1 above is divided by the gas speed U.sub.gs
defined from expression 3 below.
U gs = m x .rho. G ( .pi. L 1 2 4 ) ( Expression 3 ) C 1 .ltoreq. U
gs ( gD ) 0.5 .ltoreq. C 2 ( Expression 4 ) ##EQU00005##
[0116] Looking at the graph of FIG. 9, the value of C.sub.1 with
which the flow dividing ability becomes equal to or greater than
90% is 0.16, and the value of C.sub.2 is 1.5. Further, the value of
C.sub.1 with which the flow dividing ability becomes equal to or
greater than 95% is 0.24, and the value of C.sub.2 is 1.1.
[0117] Therefore, the value of L1 with which the flow dividing
ability is high can be decided using equality 1 and the values of
the constants C.sub.1 and C.sub.2 derived from the graph of FIG.
9.
[0118] For example, in a case where D is 500 mm, the evaporation
temperature is 7.degree. C. (.rho..sub.G decided from this
evaporation temperature becomes 122.3 kg/m.sup.3), x is 0.15, and m
is 100 kg/hr, it suffices to design L1 in such a way that L1
becomes 3.6 mm to 11.0 mm if one wants to obtain a flow dividing
ability of 90%, and it suffices to design L1 in such a way that L1
becomes 4.2 to 9.0 mm if one wants to obtain a flow dividing
ability of 95%.
(6) Characteristics
[0119] (6-1)
[0120] For example, in a case where the flat tubes are inserted
into the inside spaces of the headers through which the refrigerant
mainly travels, there is concern that the pressure loss of the
refrigerant will occur. Further, in a heat exchanger of this
configuration, when joining together the flat tubes and the
headers, it is assumed that brazing filler metal will flow into the
headers from the end portions of the flat tubes. In this case,
there is concern that the flow path through which the refrigerant
mainly travels will end up being blocked as a result of brazing
filler metal clogs or the like occurring.
[0121] Thus, in the present embodiment, the plural flat tubes 11a
to 11f are held using the flat tube holding member 132 that is
separate from the first member 131 having formed therein the
refrigerant main flow path 131a through which the refrigerant
mainly travels. Further, the intermediate flow paths 133a to 133f
for allowing the refrigerant to flow from the plural flat tubes 11a
to 11f to the refrigerant main flow path 131a and for allowing the
refrigerant from the refrigerant main flow path 131a to flow to the
flat tubes 11a to 11f are formed in the second member 133 that is
separate from the first member 131, and the refrigerant connection
flow paths 231a to 231f for allowing the refrigerant to flow from
the refrigerant main flow path 131a to the intermediate flow paths
133a to 133f are formed in the first member 131. Therefore, a
configuration in which the flat tubes 11a to 11f are not inserted
into the refrigerant main flow path 131a is employed. Because of
this, brazing filler metal clogs can be suppressed from occurring
in the refrigerant main flow path 131a through which the
refrigerant travels. Further, the pressure loss of the refrigerant
can be suppressed.
[0122] Further, by employing this configuration, the diameter of
the first header 13 and the refrigerant main flow path 131a do not
have to be formed to match the width of the flat tubes 11a to 11f.
That is, the length L1, in the direction orthogonal to the
longitudinal direction of the first member 131, of the refrigerant
main flow path forming portion 13a forming the refrigerant main
flow path 131a (that is, the inner diameter of the refrigerant main
flow path forming portion 13a) can be made smaller than the width
W22 of the flat tubes 11a to 11f. Therefore, the diameter of the
flow path through which the refrigerant mainly travels can be
reduced and the pressure-resistant strength of the first header 13
can be improved. Moreover, because the diameter of the refrigerant
main flow path 131a can be reduced, a drop in the flow speed of the
refrigerant flowing through the refrigerant main flow path 131a can
be suppressed and the flow dividing ability can be kept high.
(6-2)
[0123] In the present embodiment, the second member 133 has a flat
panel shape. Holes can be formed easily in the second member 133,
so the intermediate flow paths 133a to 133f can be formed easily.
Therefore, it is easy for a constructor to execute
construction.
(6-3)
[0124] The width W3 of the intermediate flow paths 133a to 133f
(specifically, the intermediate flow path forming portions 134a to
134f) is equal to or less than the width W22 of the flat tubes 11a
to 11f. Because of this, the longitudinal direction end surfaces of
the flat tubes 11a to 11f can be placed in contact with the second
member 133, and the positioning of the flat tubes 11a to 11f can be
performed easily. That is, the flat tubes 11a to 11f can be easily
secured in such a way that their longitudinal direction end
surfaces are positioned in substantially the same position as the
end surface of the second member 133 on the flat tube side of the
second member 133 in the thickness direction of the second member
133. Further, because of this, spaces (that is, the intermediate
flow paths 133a to 133f) can be easily formed between the first
member 131 and the flat tubes 11a to 11f.
(6-4)
[0125] In the present embodiment, the width W3 of the intermediate
flow path forming portions 134a to 134f is equal to or greater than
the width W2 of the sections of the flat tubes 11a to 11f in which
the refrigerant flow paths 112 are formed. Because of this, the
width W1 of the refrigerant connection flow paths 231a to 231f can
be set to the minimum dimension necessary for the refrigerant to
travel through, and the pressure-resistant strength of the first
header 13 improves.
(6-5)
[0126] In the present embodiment, the flat tube holding member 132
covers the second member 133 from outside, and both ends of the
flat tube holding member 132 are in contact with and joined by
brazing to the first member 131.
[0127] Here, the second member 133 can be easily secured by the
flat tube holding member 132.
[0128] Further, in the present embodiment, the inwardly bent end
portions of the flat tube holding member 132 are positioned in the
recessed portion spaces S formed by the first portion 331a and the
second portion 331b of the first member 131.
[0129] Here, because the recessed portion spaces S are formed by
the first portion 331a and the second portion 331b of the first
member 131, the securing of the flat tube holding member 132 can be
performed easily.
(6-6)
[0130] In the present embodiment, clad metal different from other
members (the flat tube holding member 132) is used for the second
member 133. Specifically, the clad metal used for the second member
133 has a higher melting point than that of the clad metal used for
other members.
[0131] This is to ensure that the brazing filler metal of the
second member 133 does not flow to the end surfaces of the flat
tubes 11a to 11f when joining together the second member 133 and
the flat tube holding member 132 because the end surfaces of the
flat tubes 11a to 11f are positioned between the second member 133
and the flat tube holding member 132. Therefore, brazing filler
metal clogs in the refrigerant flow paths 112 formed in the flat
tubes 11a to 11f can be suppressed.
(6-7)
[0132] In the present embodiment, the first member 131, the second
member 133, and the flat tube holding member 132 are configured
from clad metal, so it is not necessary to use separate brazing
filler metals when a constructor brazes these. Therefore, the
number of man-hours in the brazing work can be reduced and costs
can be suppressed.
(6-8)
[0133] In the present embodiment, the length L1, in the direction
orthogonal to the longitudinal direction of the first member 131,
of the refrigerant main flow path forming portion 13a forming the
refrigerant main flow path 131a with which the flow dividing
ability becomes higher can be easily arrived at from equality 1
above. Specifically, L1 with which the flow dividing ability
becomes higher is arrived at by deriving, from the graph shown in
FIG. 9, the values of the constants C.sub.1 and C.sub.2 with which
the flow dividing ability becomes higher.
(7) Modifications
(7-1) Modification 1A
[0134] An embodiment of the present invention has been described
above on the basis of the drawings, but the specific configurations
thereof are not limited to those in the above-described embodiment
and can be changed without departing from the gist of the
invention.
[0135] FIG. 10 is a longitudinal cross-sectional view showing the
flat tube holding member 132 pertaining to a modification.
[0136] In the above-described embodiment, only the flat tube-use
holes 132a to 132f are formed in the flat tube holding member 132,
but the present invention is not limited to this.
[0137] In addition to the flat tube-use holes 132a to 132f, plural
holes 232a to 232e may also be formed in the flat tube holding
member 132.
[0138] Here, although it is not mentioned above, when joining
together the flat tube holding member 132 and the flat tubes 11a to
11f and joining together the flat tube holding member 132 and the
second member 133, a flux is applied and thereafter these are
connected by brazing or the like. Therefore, when performing the
brazing, it is assumed that the flux will volatilize.
[0139] Therefore, by forming the plural holes 232a to 232e in the
flat tube holding member 132, it becomes easier to remove
volatilized gas, so airtightness between the flat tube holding
member 132 and the flat tubes 11a to 11f and between the flat tube
holding member 132 and the second member 133 can be ensured.
(7-2) Modification 1B
[0140] In the above-described embodiment, the second member 133 is
described as being disposed between the first member 131 and the
flat tube holding member 132, but the present invention is not
limited to this and the second member 133 does not have to be
disposed. That is, a configuration in which the end surface of the
first member 131 on the flat tube holding member side and the end
surface of the flat tube holding member 132 on the first member
side are in contact with each other may also be employed.
[0141] In modifications 1C to 1G below, employable configurations
of the headers 13 and 14 (below, only the first header 13 is
indicated) and the flat tubes 11a to 11f in this case will be
described.
(7-3) Modification 1C
[0142] FIG. 11 is a plan view, pertaining to the present
modification 1C, of the first header 13 and the flat tubes 11a to
11f in a case where the upper end member has been removed. FIG. 12
is a side view, pertaining to the present modification 1C. of the
first member 131 as seen from the side of the flat tubes 11a to
11f.
[0143] In the heat exchanger 1 pertaining to the present
modification 1C, as shown in FIG. 11 and FIG. 12, a recessed
portion 234a that is inwardly recessed across the vertical
direction of the first member 131 is formed in the end portion of
the first member 131 on the flat tube holding member side. The
recessed portion 234a functions as the intermediate flow paths 133a
to 133f of the above-described embodiment. That is, a recessed
portion forming portion 234 forming the recessed portion 234a
corresponds to the intermediate flow path forming portions 134a to
134f of the above-described embodiment.
[0144] In the heat exchanger 1 pertaining to the present
modification 1C, even in a case where the second member 133 is not
disposed between the first member 131 and the flat tube holding
member 132, effects that are the same as those of the
above-described embodiment can be expected because the recessed
portion 234a having the function of the intermediate flow paths
133a to 133f is formed in the first member 131. Further, a width
W31 of the recessed portion forming portion 234 is, like in the
above-described embodiment, equal to or less than the width W22 of
the flat tubes 11a to 11f, so when connecting the flat tubes 11a to
11f to the headers 13 and 14, the longitudinal direction end
surfaces of the flat tubes 11a to 11f come into contact with the
first member (specifically, the periphery of the recessed portion
forming portion 234). Because of this, the positioning of the flat
tubes 11a to 11f can be performed easily.
(7-4) Modification 1D
[0145] FIG. 13 is a plan view, pertaining to the present
modification 1D, of the first header 13 and the flat tubes 11a to
11f in a case where the upper end member has been removed. FIG. 14
is a side view, pertaining to the present modification 1D, of the
first member 131 as seen from the side of the flat tubes 11a to
11f.
[0146] In the heat exchanger 1 pertaining to the present
modification 1D, as shown in FIG. 14, recessed portions 254a to
254f that are inwardly recessed are formed in the end portion of
the first member 131 on the flat tube holding member side only in
positions corresponding to the height positions of the flat tubes
11a to 11f (specifically, substantially the same height positions).
That is, in the first member 131 pertaining to the present
modification 1D, plural recessed portions 254a to 254f are formed.
The recessed portions 254a to 254f function as the intermediate
flow paths 133a to 133f of the above-described embodiment. That is,
recessed portion forming portions 244a to 244f forming the recessed
portions 254a to 254f correspond to the intermediate flow path
forming portions 134a to 134f of the above-described
embodiment.
[0147] Therefore, in the heat exchanger 1 pertaining to the present
modification 1D, even in a case where the second member 133 is not
disposed between the first member 131 and the flat tube holding
member 132, effects that are the same as those of the
above-described embodiment can be expected because the recessed
portions 254a to 254f having the function of the intermediate flow
paths 133a to 133f are formed in the first member 131. Further, a
width W32 of the recessed portion forming portions 244a to 244f is
equal to or less than the width W22 of the flat tubes 11a to 11f,
so effects that are the same as those of modification 1C are also
achieved.
(7-5) Modification 1E
[0148] FIG. 15 is a plan view, pertaining to the present
modification 1E, of the first header 13 and the flat tubes 11a to
11f in a case where the upper end member has been removed.
[0149] In the heat exchanger 1 pertaining to the present
modification 1E, as shown in FIG. 15, recessed portions that are
inwardly recessed are formed in the end portions of the flat tubes
11a to 11f on the first member side (in FIG. 15, of the recessed
portions formed in the flat tubes 11a to 11f, only a recessed
portion 265a formed in the flat tube 11a is shown). The recessed
portions function as the intermediate flow paths 133a to 133f of
the above-described embodiment. That is, recessed portion forming
portions forming the recessed portions (in FIG. 15, of the recessed
portion forming portions formed in the flat tubes 11a to 11f, only
a recessed portion forming portion 255a formed in the flat tube 11a
is shown) correspond to the intermediate flow path forming portions
134a to 134f of the above-described embodiment.
[0150] In the heat exchanger 1 pertaining to the present
modification 1E, even in a case where the second member 133 is not
disposed between the first member 131 and the flat tube holding
member 132, effects that are the same as those of the
above-described embodiment can be expected because the recessed
portions having the function of the intermediate flow paths 133a to
133f are formed in the flat tubes 11a to 11f. Further, a width W33
of the recessed portion forming portions is, like in the
above-described embodiment, equal to or less than the width W22 of
the flat tubes 11a to 11f. Therefore, when connecting the flat
tubes 11a to 11f to the headers 13 and 14, the longitudinal
direction end surfaces of the flat tubes 11a to 11f come into
contact with the first member 131. Because of this, the positioning
of the flat tubes 11a to 11f can be performed easily.
(7-6) Modification 1F
[0151] FIG. 16 is a plan view, pertaining to the present
modification 1F, of the first header 13 and the flat tubes 11a to
11f in a case where the upper end member has been removed.
[0152] In the heat exchanger 1 pertaining to the present
modification 1F, as shown in FIG. 16, both longitudinal direction
end portions of the flat tubes 11a to 11f have convex shapes as
seen in a plan view. Specifically, the flat tubes 11a to 11f have
corner portions (in FIG. 16, only a corner portion 121a of the flat
tube 11a is shown) cut squarely as seen in a plan view. The outer
surfaces of the corner portions of the flat tubes 11a to 11f are in
contact with the flat tube holding member 132 (specifically, the
outer surfaces of the corner portions of the flat tubes 11a to 11f
are in contact with the outer surface of the flat tube holding
member 132 and the inner surfaces of the sections forming the flat
tube-use holes 132a to 132f).
[0153] Further, the corner portions of the flat tubes 11a to 11f
are formed in such a way that, in a state in which the outer
surfaces of the corner portions of the flat tubes 11a to 11f are in
contact with the flat tube holding member 132, a space S1 is formed
between the flat tube holding member 132, the flat tubes 11a to
11f, and the first member 131. Additionally, this space S1
functions as the intermediate flow paths 133a to 133f of the
above-described embodiment. A longitudinal direction width W34 of
the space S1 (that is, the distance between sections 332 of the
flat tube holding member 132 that form the space S1) is smaller
than the width W22 of the flat tubes 11a to 11f.
[0154] As described above, in the heat exchanger 1 pertaining to
the present modification 1F, even in a case where the second member
133 is not disposed between the first member 131 and the flat tube
holding member 132, effects that are the same as those of the
above-described embodiment can be expected because the space S1
functions as the intermediate flow paths 133a to 133f. Further, the
positioning of the flat tubes 11a to 11f can be performed
easily.
(7-7) Modification 1G
[0155] FIG. 17 is a plan view, pertaining to the present
modification 1G of the first header 13 and the flat tubes 11a to
11f in a case where the upper end member has been removed.
[0156] In the heat exchanger 1 pertaining to the present
modification 1G, as shown in FIG. 17, convex portions 171 are
formed on both width direction end portions of both longitudinal
direction end portions of the flat tubes 11a to 11f. The outer
surfaces of the convex portions 171 opposing the flat tube holding
member 132 are in contact with the flat tube holding member 132 in
a state in which the flat tubes 11a to 11f are positioned in their
regular positions. The convex portions 171 are formed in positions
such that a space S2 is formed between the flat tube holding member
132, the flat tubes 11a to 11f, and the first member 131 in a state
in which the flat tubes 11a to 11f are positioned in their regular
positions. The space S2 functions as the intermediate flow paths
133a to 133f of the above-described embodiment. In this state, a
longitudinal direction width W35 of the space S2 is the same as the
width W22 of the flat tubes 11a to 11f.
[0157] As described above, in the heat exchanger 1 pertaining to
the present modification 1G, because of the convex portions 171,
the positioning of the flat tubes 11a to 11f can be performed
easily and effects that are the same as those of the
above-described embodiment are also achieved.
(7-8) Modification 1H
[0158] In the above-described embodiment, the length, in the
direction orthogonal to the longitudinal direction of the headers
13 and 14, of the refrigerant main flow path forming portions
forming the refrigerant main flow paths in the headers 13 and 14 is
the same from the upper ends to the lower ends of the headers 13
and 14, but the present invention is not limited to this.
[0159] For example, the length of the header through which liquid
refrigerant flows may also be made smaller than the length of the
header through which gas refrigerant flows. Because of this, a drop
in the refrigerant flow speed of the liquid refrigerant can be
suppressed and the flow dividing ability can be improved.
Second Embodiment
[0160] Next, a second embodiment will be described. In the
description below, the same reference signs will be given to
components and so forth that are the same as those in the first
embodiment and description will be omitted.
[0161] That which mainly differs in the second embodiment from the
first embodiment is that a securing member 210 for more stably
securing the flat tubes 11a to 11f is interposed between the flat
tube holding member 132 and the second member 133. Therefore, the
securing member 210 will be described below.
(1) Securing Member 210
[0162] FIG. 18 is a plan view of the first header 13 and the flat
tubes 11a to 11f in a case where the upper end member has been
removed. FIG. 19 is a longitudinal cross-sectional view in a case
where the first header 13 and the flat tubes 11a to 11f in a case
where the upper end member and the lower end member have been
removed are cut along line XIX-XIX shown in FIG. 18. FIG. 20 is a
longitudinal cross-sectional view in a case where the securing
member 210 is cut along line XX-XX shown in FIG. 18.
[0163] As shown in FIG. 18 and FIG. 19, the securing member 210 is
sandwiched between the flat tube holding member 132 and the second
member 133. Further, the securing member 210 has the role of
securing the end portions of the plural flat tubes 11a to 11f
together with the flat tube holding member 132. The securing member
210 is configured from a metal member such as clad metal and has a
long and narrow flat panel shape extending in the vertical
direction.
[0164] As shown in FIG. 20, plural flat tube securing holes 210a to
210f having long and narrow shapes in the width direction of the
securing member 210 are formed in the securing member 210 at
predetermined intervals apart from each other along the
longitudinal direction of the securing member 210. Specifically,
the flat tube securing holes 210a to 210f are formed by flat tube
securing hole forming portions 220a to 220f of the securing member
210. The flat tube securing hole forming portions 220a to 220f have
projecting portions 230a to 230f at which both height direction
edges of each of the flat tube securing hole forming portions 220a
to 220f become closer to each other. A height direction length H2
of the spaces formed by the projecting portions 230a to 230f is
smaller than the thickness of the flat tubes 11a to 11f. Because of
this, the flat tubes 11a to 11f are held. The flat tube securing
holes 210a to 210f are formed by stamping.
[0165] The method of manufacturing the heat exchanger 1 of the
second embodiment is substantially the same as that of the first
embodiment simply as a result of adding, to the process of the
method of manufacturing the heat exchanger 1 of the first
embodiment, forming the securing member 210, joining together the
second member 133 and the securing member 210, and joining together
the securing member 210 and the flat tube holding member 132.
(2) Characteristics
[0166] (2-1)
[0167] In the second embodiment, by interposing the securing member
210 between the flat tube holding member 132 and the second member
133, the flat tubes 11a to 11f can be more stably secured. Further,
by interposing the securing member 210, the sections of the flat
tubes 11a to 11f inserted into the first header 13 can be changed
in the range of the thickness of the securing member 210.
Therefore, when joining together the first header 13 and the flat
tubes 11a to 11f, inflow of the brazing filler metal from the
second member 133 into the refrigerant flow paths 112 formed in the
flat tubes 11a to 11f can be suppressed.
(2-2)
[0168] The securing member 210 has a flat panel shape as described
above. Because of this, the flat tube securing holes 210a to 210f
can be easily formed in the securing member 210. Therefore, it is
easy for a constructor to execute construction.
(2-3)
[0169] The flat tube holding member 132 in the second embodiment
covers the securing member 210 from outside in addition to the
second member 133, so not just the second member 133 but also the
securing member 210 can be easily secured.
INDUSTRIAL APPLICABILITY
[0170] The present invention is applicable to a variety of heat
exchangers configured from headers that extend in a vertical
direction and plural flat tubes that extend in a direction
orthogonal to the length of the headers and are inserted into the
headers.
REFERENCE SIGNS LIST
[0171] 1 Heat Exchanger [0172] 11a to 11f Flat Tubes [0173] 13, 14
Headers [0174] 112 Refrigerant Flow Paths in Flat Tubes [0175] 131
First Member [0176] 131a Refrigerant Main Flow Path (Main Flow
Path) [0177] 132 Flat Tube Holding Member [0178] 133 Second Member
[0179] 133a to 133f Intermediate Flow Paths [0180] 210 Securing
Member [0181] 231a to 231f Refrigerant Connection Flow Paths [0182]
W1 Width of Refrigerant Connection Flow Paths [0183] W2 Width of
Sections of Flat Tubes in Which Refrigerant Flow Paths are Formed
[0184] W3 Width of Intermediate Flow Paths
CITATION LIST
Patent Literature
[0184] [0185] Patent Citation 1: JP-A No. 2006-284133
* * * * *