U.S. patent application number 10/563599 was filed with the patent office on 2006-09-28 for heat exchanger.
This patent application is currently assigned to Showa Denko K.K.. Invention is credited to Naohisa Higashiyama, Sumitaka Watanabe, Shinobu Yamauchi.
Application Number | 20060213651 10/563599 |
Document ID | / |
Family ID | 33568735 |
Filed Date | 2006-09-28 |
United States Patent
Application |
20060213651 |
Kind Code |
A1 |
Higashiyama; Naohisa ; et
al. |
September 28, 2006 |
Heat exchanger
Abstract
A heat exchanger includes a refrigerant inlet-outlet tank, a
refrigerant turn tank, and tube groups in the form of at least two
rows arranged between the two tanks, and each including a plurality
of heat exchange tubes. The refrigerant inlet-outlet tank has its
interior divided into a refrigerant inlet header chamber and a
refrigerant outlet header chamber. The refrigerant turn tank has
its interior divided by a divided flow control plate into a
refrigerant inflow header chamber and a refrigerant outflow header
chamber. The divided flow control plate has refrigerant dam
portions at respective opposite end portions thereof, and a
refrigerant passing portion provided between the dam portions and
having one or at least two refrigerant passing holes. The heat
exchanger exhibits improved heat exchange performance when used as
an evaporator.
Inventors: |
Higashiyama; Naohisa;
(Tochigi, JP) ; Watanabe; Sumitaka; (Tochigi,
JP) ; Yamauchi; Shinobu; (Tochigi, JP) |
Correspondence
Address: |
C. IRVIN MCCLELLAND;OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Showa Denko K.K.
Tokyo
JP
105-8518
|
Family ID: |
33568735 |
Appl. No.: |
10/563599 |
Filed: |
July 8, 2004 |
PCT Filed: |
July 8, 2004 |
PCT NO: |
PCT/JP04/10069 |
371 Date: |
January 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60486897 |
Jul 15, 2003 |
|
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60486898 |
Jul 15, 2003 |
|
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Current U.S.
Class: |
165/174 ;
165/153; 165/173; 165/176 |
Current CPC
Class: |
F28F 9/0278 20130101;
F28F 9/0202 20130101; F28F 9/0224 20130101; F28D 1/05391 20130101;
F28D 2021/0085 20130101; F28F 9/0214 20130101 |
Class at
Publication: |
165/174 ;
165/176; 165/153; 165/173 |
International
Class: |
F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2003 |
JP |
2003-272043 |
Jul 8, 2003 |
JP |
2003-272057 |
Claims
1. A heat exchanger comprising a refrigerant inlet-outlet tank and
a refrigerant turn tank arranged as spaced apart from each other,
and a plurality of tube groups in the form of rows arranged at a
spacing in the direction of flow of air through the heat exchanger
between the tanks and each comprising a plurality of heat exchange
tubes arranged in parallel at a spacing longitudinally of the
tanks, the heat exchange tubes of each tube group having opposite
ends joined to the respective tanks, the refrigerant inlet-outlet
tank having interior divided by a partition wall into a refrigerant
inlet header chamber and a refrigerant outlet header chamber
arranged in the direction of flow of air, each of the two header
chambers being in communication with the heat exchange tubes of the
tube group of at least one row, a refrigerant flowing into the
inlet header chamber of the refrigerant inlet-outlet tank being
flowable through the corresponding heat exchange tubes into the
refrigerant turn tank, where the refrigerant changes its course to
flow into the outlet header chamber of the refrigerant inlet-outlet
tank through the corresponding heat exchange tubes, the refrigerant
turn tank being provide with a uniformalizing member for making
uniform divided flows of the refrigerant from the inlet header
chamber into the heat exchange tubes communicating with the inlet
header chamber.
2. A heat exchanger according to claim 1 wherein the uniformalizing
member comprises a divided flow control plate dividing the interior
of the refrigerant turn tank into two spaces arranged in the
direction of flow of air, the two spaces being in communication
with each other, the heat exchange tubes in communication with the
inlet header chamber communicating with one of the spaces of the
refrigerant turn tank, the heat exchange tubes in communication
with the outlet header chamber communicating with the other space
of the refrigerant turn tank.
3. A heat exchanger according to claim 2 wherein the divided flow
control plate has one or at least two refrigerant passing holes
formed therein, and the two spaces are held in communication
through the refrigerant passing holes.
4. A heat exchanger according to claim 3 wherein the refrigerant
flows through the refrigerant passing holes in the divided flow
control plate in counter current relation with the flow of air.
5. A heat exchanger according to claim 3 wherein the divided flow
control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the combined area of all
the refrigerant passing holes formed in the refrigerant passing
portion being 130 to 510 mm.sup.2.
6. A heat exchanger according to claim 3 wherein the divided flow
control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the heat exchanger being
20 to 75% in opening ratio which is the ratio of the number of
refrigerant passing holes formed in the refrigerant passing portion
to the number of heat exchange tubes of each tube group.
7. A heat exchanger according to claim 3 wherein the divided flow
control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the combined area of all
the refrigerant passing holes formed in the refrigerant passing
portion being 130 to 510 mm.sup.2, the heat exchanger being 20 to
75% in opening ratio which is the ratio of the number of
refrigerant passing holes formed in the refrigerant passing portion
to the number of heat exchange tubes of each tube group.
8. A heat exchanger according to claim 2 wherein the refrigerant
turn tank comprises a first member of aluminum having the heat
exchange tubes joined thereto, and a second member of an aluminum
extrudate brazed to the first member at a portion thereof opposite
to the heat exchange tubes, and the divided flow control plate is
integral with the second member.
9. A heat exchanger according to claim 1 wherein the outlet header
chamber of the refrigerant inlet-outlet tank has interior divided
by a partition plate into a first space communicating with the
corresponding heat exchange tubes and a second space for the
refrigerant to flow out therefrom, the two spaces being in
communication with each other.
10. A heat exchanger according to claim 9 wherein the partition
plate has one or at least two refrigerant passing holes formed
therein, and the two spaces are held in communication through the
refrigerant passing holes.
11. A heat exchanger according to claim 9 wherein the refrigerant
inlet-outlet tank comprises a first member of aluminum having the
heat exchange tubes joined thereto, and a second member of an
aluminum extrudate brazed to the first member at a portion thereof
opposite to the heat exchange tubes, and the partition wall and the
partition plate are integral with the second member.
12. A heat exchanger according to claim 9 wherein the refrigerant
inlet-outlet tank is provided at one end thereof with a refrigerant
inlet communicating with the inlet header chamber and a refrigerant
outlet communicating with the second space of the outlet header
chamber.
13. A heat exchanger according to claim 1 wherein each tube group
comprises at least seven heat exchange tubes.
14. A refrigeration cycle comprising a compressor, a condenser and
an evaporator, the evaporator being a heat exchanger according to
claim 1.
15. A vehicle having installed therein a refrigeration cycle
according to claim 14 as an air conditioner.
16. A heat exchanger comprising a refrigerant inlet-outlet tank and
a refrigerant turn tank arranged as spaced apart from each other,
and a plurality of tube groups in the form of rows arranged at a
spacing in the direction of flow of air through the heat exchanger
between the tanks and each comprising a plurality of heat exchange
tubes arranged in parallel at a spacing longitudinally of the
tanks, the heat exchange tubes of each tube group having opposite
ends joined to the respective tanks, the refrigerant inlet-outlet
tank having interior divided by a partition wall into a refrigerant
inlet header chamber and a refrigerant outlet header chamber
arranged in the direction of flow of air, each of the two header
chambers being in communication with the heat exchange tubes of the
tube group of at least one row, a refrigerant flowing into the
inlet header chamber of the refrigerant inlet-outlet tank being
flowable through the corresponding heat exchange tubes into the
refrigerant turn tank, where the refrigerant changes its course to
flow into the outlet header chamber of the refrigerant inlet-outlet
tank through the corresponding heat exchange tubes, the inlet
header chamber of the refrigerant inlet-outlet tank having interior
divided by a flow dividing resistance plate into a first space
communicating with the corresponding heat exchange tubes and a
second space for the refrigerant to flow in, the flow dividing
resistance plate having one refrigerant passing hole formed
therein.
17. A heat exchanger according to claim 16 wherein the refrigerant
passing hole is formed at a longitudinal midportion of the flow
dividing resistance plate.
18. A heat exchanger according to claim 16 wherein the refrigerant
passing hole is positioned between a pair of heat exchange tubes
adjacent to each other longitudinally of the refrigerant
inlet-outlet tank and included among the heat exchange tubes in
communication with the inlet header chamber of the refrigerant
inlet-outlet tank.
19. A heat exchanger according to claim 16 wherein the refrigerant
passing hole has an area larger than the combined cross sectional
area of refrigerant channels in one heat exchange tube.
20. A heat exchanger according to claim 16 wherein the refrigerant
passing hole is circular and has a diameter of 3 to 8 mm.
21. A heat exchanger according to claim 16 wherein the refrigerant
inlet-outlet tank has a wall portion to which the heat exchange
tubes communicating with the first space are joined and which has a
flow dividing member inwardly projecting from a part thereof
corresponding to the refrigerant passing hole for causing the
refrigerant to dividedly flow longitudinally of the inlet header
chamber upon flowing through the refrigerant passing hole.
22. A heat exchanger according to claim 21 wherein the flow
dividing member is a ridge projecting toward the resistance plate
in the form of an angle and extending widthwise of the inlet header
chamber.
23. A heat exchanger according to claim 16 wherein the outlet
header chamber of the refrigerant inlet-outlet tank has interior
divided by a partition plate into a first space communicating with
the corresponding heat exchange tubes and a second space for the
refrigerant to flow out therefrom, and a refrigerant passing hole
is formed in the partition plate.
24. A heat exchanger according to claim 23 wherein the refrigerant
inlet-outlet tank comprises a first member of aluminum having the
heat exchange tubes joined thereto, and a second member of an
aluminum extrudate brazed to the first member at a portion thereof
opposite to the heat exchange tubes, and the partition wall, the
flow dividing resistance plate and the partition plate are integral
with the second member.
25. A heat exchanger according to claim 16 wherein the refrigerant
inlet-outlet tank is provided at one end thereof with a refrigerant
inlet communicating with the second space of the inlet header
chamber and a refrigerant outlet communicating with the outlet
header chamber.
26. A heat exchanger according to claim 16 wherein the refrigerant
turn tank has interior divided by a divided flow control plate into
a first space in communication with the heat exchange tubes
communicating with the first space of the inlet header chamber of
the refrigerant inlet-outlet tank and a second space communicating
with the heat exchange tubes communicating with the outlet header
chamber of the refrigerant inlet-outlet tank, and the divided flow
control plate has a refrigerant dam portion at a position
corresponding to the refrigerant passing hole in the flow dividing
resistance plate with respect to the longitudinal direction of the
two tanks, the divided flow control plate being provided with a
refrigerant passing portion having a refrigerant passing hole at a
position other than the dam portion.
27. A heat exchanger according to claim 26 wherein the refrigerant
dam portion of the divided flow control plate has a length of at
least 28 mm.
28. A heat exchanger according to claim 26 which is 20 to 90% in
opening ratio which is the ratio of the number of refrigerant
passing holes formed in the divided flow control plate to the
number of heat exchange tubes in each tube group.
29. A heat exchanger according to claim 26 wherein the refrigerant
turn tank comprises a first member of aluminum having the heat
exchange tubes joined thereto, and a second member of an aluminum
extrudate brazed to the first member at a portion thereof opposite
to the heat exchange tubes, and the divided flow control plate is
integral with the second member.
30. A refrigeration cycle comprising a compressor, a condenser and
an evaporator, the evaporator being a heat exchanger according to
claim 16.
31. A vehicle having installed therein a refrigeration cycle
according to claim 30 as an air conditioner.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is an application filed under 35 U.S.C.
.sctn.111(a) claiming the benefit pursuant to 35 U.S.C.
.sctn.119(e) (1) of the filing dates of Provisional Applications
No. 60/486, 897 and No. 60/486,898 both filed Jul. 15, 2003
pursuant to 35 U.S.C. .sctn.111(b).
TECHNICAL FIELD
[0002] The present invention relates to heat exchangers, and more
particularly to heat exchangers suitable for use as the evaporators
of motor vehicle air conditioners which are refrigeration cycles to
be installed in motor vehicles.
[0003] The term "aluminum" as used herein and in the appended
claims includes aluminum alloys in addition to pure aluminum.
BACKGROUND ART
[0004] Heretofore in wide use as motor vehicle evaporators are
those of the so-called stacked plate type which comprise a
plurality of flat hollow bodies arranged in parallel and each
composed of a pair of dishlike plates facing toward each other and
brazed to each other along peripheral edges thereof, and a louvered
corrugated fin disposed between and brazed to each adjacent pair of
flat hollow bodies. In recent years, however, it has been demanded
to provide evaporators further reduced in size and weight and
exhibiting higher performance.
[0005] To meet such a demand, the present applicant has already
proposed evaporators which comprise a refrigerant inlet-outlet tank
and a refrigerant turn tank arranged as spaced apart from each
other, and a plurality of tube groups arranged in two rows as
spaced apart in the direction of passage of air through the
evaporator between the tanks and each comprising a plurality of
heat exchange tubes arranged in parallel at a spacing
longitudinally of the tanks, the heat exchange tubes of each tube
group having opposite ends joined to the respective tanks, the
refrigerant inlet-outlet tank having its interior divided by a
partition wall into a refrigerant inlet header chamber and a
refrigerant outlet header chamber arranged in the direction of
passage of air, the two header chambers being in communication with
the heat exchange tubes of the respective two tube groups, a
refrigerant flowing into the inlet header chamber of the
refrigerant inlet-outlet tank being flowable through the
corresponding heat exchange tubes into the refrigerant turn tank,
where the refrigerant changes its course to flow into the outlet
header chamber of the refrigerant inlet-outlet tank through the
corresponding heat exchange tubes, the outlet header chamber having
its interior divided into a first space in communication with the
corresponding heat exchange tubes and a second space for the
refrigerant to flow out therefrom, by a partition plate having
refrigerant passing holes (see the publication of JP-A No.
2003-75024). With this evaporator, the partition plate having the
refrigerant passing holes and provided inside the outlet header
chamber functions to permit the refrigerant to flow through the
heat exchange tubes of the two tube groups in uniform quantities,
thereby enabling the evaporator to exhibit improved heat exchange
performance.
[0006] However, extended research conducted by the present
inventors has revealed that the evaporator disclosed in the above
publication still remains to be improved in making the refrigerant
to flow through the heat exchange tubes of the tube groups in
uniform quantities and in heat exchange performance.
[0007] An object of the present-invention is to overcome the above
problem and to provide a heat exchanger which is outstanding in
heat exchange performance.
DISCLOSURE OF THE INVENTION
[0008] To fulfill the above object, the present invention comprises
the following modes.
[0009] 1) A heat exchanger comprising a refrigerant inlet-outlet
tank and a refrigerant turn tank arranged as spaced apart from each
other, and a plurality of tube groups in the form of rows arranged
at a spacing in the direction of flow of air through the heat
exchanger between the tanks and each comprising a plurality of heat
exchange tubes arranged in parallel at a spacing longitudinally of
the tanks, the heat exchange tubes of each tube group having
opposite ends joined to the respective tanks, the refrigerant
inlet-outlet tank having interior divided by a partition wall into
a refrigerant inlet header chamber and a refrigerant outlet- header
chamber arranged in the direction of flow of air, each of the two
header chambers being in communication with the heat exchange tubes
of the tube group of at least one row, a refrigerant flowing into
the inlet header chamber of the refrigerant inlet-outlet tank being
flowable through the corresponding heat exchange tubes into the
refrigerant turn tank, where the refrigerant changes its course to
flow into the outlet header chamber of the refrigerant inlet-outlet
tank through the corresponding heat exchange tubes,
[0010] the refrigerant turn tank being provide with a
uniformalizing member for making uniform divided flows of the
refrigerant from the inlet header chamber into the heat exchange
tubes communicating with the inlet header chamber.
[0011] 2) A heat exchanger described in par. 1) wherein the
uniformalizing member comprises a divided flow control plate
dividing the interior of the refrigerant turn tank into two spaces
arranged in the direction of flow of air, the two spaces being in
communication with each other, the heat exchange tubes in
communication with the inlet header chamber communicating with one
of the spaces of the refrigerant turn tank, the heat exchange tubes
in communication with the outlet header chamber communicating with
the other space of the refrigerant turn tank.
[0012] 3) A heat exchanger described in par. 2) wherein the divided
flow control plate has one or at least two refrigerant passing
holes formed therein, and the two spaces are held in communication
through the refrigerant passing holes
[0013] 4) A heat exchanger described in par. 3) wherein the
refrigerant flows through the refrigerant passing holes in the
divided flow control plate in counter current relation with the
flow of air.
[0014] 5) A heat exchanger described in par. 3) wherein the divided
flow control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the combined area of all
the refrigerant passing holes formed in the refrigerant passing
portion being 130 to 510 mm.sup.2.
[0015] 6) A heat exchanger described in par. 3) wherein the divided
flow control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the heat exchanger being
20 to 75% in opening ratio which is the ratio of the number of
refrigerant passing holes formed in the refrigerant passing portion
to the number of heat exchange tubes of each tube group.
[0016] 7) A heat exchanger described in par. 3) wherein the divided
flow control plate has two refrigerant dam portions at respective
opposite end portions thereof and is provided between the two
refrigerant dam portions with a refrigerant passing portion having
one or at least two refrigerant passing holes, the length of each
of the refrigerant dam portions being at least 15% of the entire
length of the divided flow control plate, the combined area of all
the refrigerant passing holes formed in the refrigerant passing
portion being 130 to 510 mm.sup.2, the heat exchanger being 20 to
75% in opening ratio which is the ratio of the number of
refrigerant passing holes formed in the refrigerant passing portion
to the number of heat exchange tubes of each tube group.
[0017] 8) A heat exchanger described in par. 2) wherein the
refrigerant turn tank comprises a first member of aluminum having
the heat exchange tubes joined thereto, and a second member of an
aluminum extrudate brazed to the first member at a portion thereof
opposite to the heat exchange tubes, and the divided flow control
plate is integral with the second member.
[0018] 9) A heat exchanger described in par. 1) wherein the outlet
header chamber of the refrigerant inlet-outlet tank has interior
divided by a partition plate into a first space communicating with
the corresponding heat exchange tubes and a second space for the
refrigerant to flow out therefrom, the two spaces being in
communication with each other.
[0019] 10) A heat exchanger described in par. 9) wherein the
partition plate has one or at least two refrigerant passing holes
formed therein, and the two spaces are held in communication
through the refrigerant passing holes.
[0020] 11) A heat exchanger described in par. 9) wherein the
refrigerant inlet-outlet tank comprises a first member of aluminum
having the heat exchange tubes joined thereto, and a second member
of an aluminum extrudate brazed to the first member at a portion
thereof opposite to the heat exchange tubes, and the partition wall
and the partition plate are integral with the second member.
[0021] 12) A heat exchanger described in par. 9) wherein the
refrigerant inlet-outlet tank is provided at one end thereof with a
refrigerant inlet communicating with the inlet header chamber and a
refrigerant outlet communicating with the second space of the
outlet header chamber.
[0022] 13) A heat exchanger described in par. 1) wherein each tube
group comprises at least seven heat exchange tubes. 14) A
refrigeration cycle comprising a compressor, a condenser and an
evaporator, the evaporator being a heat exchanger described in any
one of par. 1) to 13).
[0023] 15) A vehicle having installed therein a refrigeration cycle
described in par. 14) as an air conditioner. 16) A heat exchanger
comprising a refrigerant inlet-outlet tank and a refrigerant turn
tank arranged as spaced apart from each other, and a plurality of
tube groups in the form of rows arranged at a spacing in the
direction of flow of air through the heat exchanger between the
tanks and each comprising a plurality of heat exchange tubes
arranged in parallel at a spacing longitudinally of the tanks, the
heat exchange tubes of each tube group having opposite ends joined
to the respective tanks, the refrigerant inlet-outlet tank having
interior divided by a partition wall into a refrigerant inlet
header chamber and a refrigerant outlet header chamber arranged in
the direction of flow of air, each of the two header chambers being
in communication with the heat exchange tubes of the tube group of
at least one row, a refrigerant flowing into the inlet header
chamber of the refrigerant inlet-outlet tank being flowable through
the corresponding heat exchange tubes into the refrigerant turn
tank, where the refrigerant changes its course to flow into the
outlet header chamber of the refrigerant inlet-outlet tank through
the corresponding heat exchange tubes,
[0024] the inlet header chamber of the refrigerant inlet-outlet
tank having interior divided by a flow dividing resistance plate
into a first space communicating with the corresponding heat
exchange tubes and a second space for the refrigerant to flow in,
the flow dividing resistance plate having one refrigerant passing
hole formed therein.
[0025] 17) A heat exchanger described in par. 16) wherein the
refrigerant passing hole is formed at a longitudinal midportion of
the flow dividing resistance plate.
[0026] 18) A heat exchanger described in par. 16) wherein the
refrigerant passing hole is positioned between a pair of heat
exchange tubes adjacent to each other longitudinally of the
refrigerant inlet-outlet tank and included among the heat exchange
tubes in communication with the inlet header chamber of the
refrigerant inlet-outlet tank.
[0027] 19) A heat exchanger described in par. 16) wherein the
refrigerant passing hole has an area larger than the combined cross
sectional area of refrigerant channels in one heat exchange
tube.
[0028] 20) A heat exchanger described in par. 16) wherein the
refrigerant passing hole is circular and has a diameter of 3 to 8
mm.
[0029] 21) A heat exchanger described in par. 16) wherein the
refrigerant inlet-outlet tank has a wall portion to which the heat
exchange tubes communicating with the first space are joined and
which has a flow dividing member inwardly projecting from a part
thereof corresponding to the refrigerant passing hole for causing
the refrigerant to dividedly flow longitudinally of the inlet
header chamber upon flowing through the refrigerant passing
hole.
[0030] 22) A heat exchanger described in par. 21) wherein the flow
dividing member is a ridge projecting toward the resistance plate
in the form of an angle and extending widthwise of the inlet header
chamber.
[0031] 23) A heat exchanger described in par. 16) wherein the
outlet header chamber of the refrigerant inlet-outlet tank has
interior divided by a partition plate into a first space
communicating with the corresponding heat exchange tubes and a
second space for the refrigerant to flow out therefrom, and a
refrigerant passing hole is formed in the partition plate.
[0032] 24) A heat exchanger described in par. 23) wherein the
refrigerant inlet-outlet tank comprises a first member of aluminum
having the heat exchange tubes joined thereto, and a second member
of an aluminum extrudate brazed to the first member at a portion
thereof opposite to the heat exchange tubes, and the partition
wall, the flow dividing resistance plate and the partition plate
are integral with the second member.
[0033] 25) A heat exchanger described in par. 16) wherein the
refrigerant inlet-outlet tank is provided at one end thereof with a
refrigerant inlet communicating with the second space of the inlet
header chamber and a refrigerant outlet communicating with the
outlet header chamber.
[0034] 26) A heat exchanger described in par. 16) wherein the
refrigerant turn tank has interior divided by a divided flow
control plate into a first space in communication with the heat
exchange tubes communicating with the first space of the inlet
header chamber of the refrigerant inlet-outlet tank and a second
space communicating with the heat exchange tubes communicating with
the outlet header chamber of the refrigerant inlet-outlet tank, and
the divided flow control plate has a refrigerant dam portion at a
position corresponding to the refrigerant passing hole in the flow
dividing resistance plate with respect to the longitudinal
direction of the two tanks, the divided flow control plate being
provided with a refrigerant passing portion having a refrigerant
passing hole at a position other than the dam portion.
[0035] 27) A heat exchanger described in par. 26) wherein the
refrigerant dam portion of the divided flow control plate has a
length of at least 28 mm.
[0036] 28) A heat exchanger described in par. 26) which is 20 to
90% in opening ratio which is the ratio of the number of
refrigerant passing holes formed in the divided flow control plate
to the number of heat exchange tubes in each tube group.
[0037] 29) A heat exchanger described in par. 26) wherein the
refrigerant turn tank comprises a first member of aluminum having
the heat exchange tubes joined thereto, and a second member of an
aluminum extrudate brazed to the first member at a portion thereof
opposite to the heat exchange tubes, and the divided flow control
plate is integral with the second member.
[0038] 30) A refrigeration cycle comprising a compressor, a
condenser and an evaporator, the evaporator being a heat exchanger
described in any one of par. 16) to 29). 31) A vehicle having
installed therein a refrigeration cycle described in par. 30) as an
air conditioner.
[0039] With the heat exchangers described in par. 1) to 4), the
divided flow uniformalizing member acts to cause therefrigerant to
flow through the heat exchange tubes connected to the inlet header
chamber of the inlet-outlet tank in uniform quantities, i.e.,
uniform rates, enabling the heat exchanger to exhibit improved heat
exchange performance.
[0040] With the heat exchangers described in par. 5) to 7), the
refrigerant can be passed through the heat exchange tubes connected
to the inlet header chamber of the refrigerant inlet-outlet tank in
uniform quantities, permitting the heat exchanger to achieve an
improved heat exchange efficiency.
[0041] In the case of the heat exchanger described in par. 8), the
divided flow control plate of the refrigerant turn tank is formed
integrally with the second member of aluminum extrudate. The
control plate can therefore be provided inside the refrigerant turn
tank by a simple procedure.
[0042] With the heat exchangers described in par. 9) and 10), the
partition plate functions to cause the refrigerant to flow through
the heat exchange tubes connected to the inlet header chamber of
the refrigerant inlet-outlet tank in uniform quantities and through
the heat exchange tubes connected to the outlet header chamber of
the inlet-outlet tank also in uniform quantities, consequently
enabling the heat exchanger to exhibit further improved heat
exchange performance.
[0043] Since the partition wall and partition plate of the
refrigerant inlet-outlet tank are formed integrally with the second
member in the heat exchanger described in par. 11), the partition
wall and partition plate can be provided inside the inlet-outlet
tank by a simple procedure.
[0044] In the case where the refrigerant inlet-outlet tank is
provided at one end thereof with a refrigerant inlet communicating
with the inlet header chamber and a refrigerant outlet
communicating with the second space of the outlet header chamber as
in the heat exchanger described in par. 12), the refrigerant flows
through the heat exchange tubes of the tube groups markedly
unevenly, whereas even in this case, the refrigerant flow through
the heat exchange tubes can be made uniform when the heat exchanger
has the feature described in any one of par. 1) to 7), 9) and
10).
[0045] In the case where each tube group comprises at least seven
heat exchange tubes as in the heat exchanger described in par. 13),
the refrigerant flows through the heat exchange tubes of the tube
groups markedly unevenly, whereas even in this case, the
refrigerant flow through the heat exchange tubes can be made
uniform if the heat exchanger has the feature described in any one
of par. 1) to 7), 9) and 10).
[0046] With the heat exchanger described in par. 16), the
refrigerant is admitted into the second space of the inlet header
chamber of the refrigerant inlet-outlet tank, flows through the
single refrigerant passing hole in the flow dividing resistance
plate into the first space, from which the refrigerant dividedly
flows through all the heat exchange tubes communicating with the
inlet header chamber. Because the resistance plate has only one
refrigerant passing hole formed therein, the refrigerant gently
flows from the second space into the first space to spread over the
entire area of the first space and flow into all the heat exchange
tubes. Accordingly, the refrigerant is allowed to flow through the
heat exchange tubes communicating with the inlet header chamber of
the inlet-outlet tank in uniform quantities, enabling the heat
exchanger to exhibit improved heat exchange performance.
[0047] With the heat exchangers described in par. 17) to 20), the
heat exchange tubes communicating with the inlet header chamber of
the refrigerant inlet-outlet tank are made further uniform in the
quantities of refrigerant flowing therethrough, permitting the heat
exchanger to achieve an improved heat exchange efficiency.
[0048] The heat exchangers described in par. 21) and 22) are so
adapted that the refrigerant flowing through the refrigerant
passing hole of the flow dividing resistance plate can be made to
spread over the entire area of the first space of the inlet header
chamber with a high efficiency. The heat exchange tubes
communicating with the inlet header chamber of the refrigerant
inlet-outlet tank are therefore made uniform to a greater extent in
the quantities of refrigerant flowing therethrough, permitting the
heat exchanger to achieve an improved heat exchange efficiency.
[0049] With the heat exchanger described in par. 23), the
refrigerant changes its course inside the refrigerant turn tank,
flows into the first space of the outlet header chamber of the
refrigerant inlet-outlet tank, flows through the refrigerant
passing holes of the partition plate into the second space. The
resistance offered by the partition plate to the flow of
refrigerant serves to further uniformalize the divided flows from
the first space of the inlet header chamber into the heat exchange
tubes communicating therewith, also uniformalizing the divided
flows from the refrigerant turn tank into the heat exchange tube
communicating therewith. Consequently, the refrigerant is made to
flow through the heat exchange tubes of all the tube groups in
uniform quantities for the heat exchange to exhibit improved heat
exchange performance.
[0050] With the heat exchanger described in par. 24), the partition
wall, flow dividing resistance plate and partition plate are formed
integrally with the second member. This facilitates the procedure
for providing the partition wall, flow diving resistance plate and
partition plate inside the refrigerant inlet-outlet tank.
[0051] When the refrigerant inlet-outlet tank is provided at one
end thereof with a refrigerant inlet communicating with the inlet
header chamber and a refrigerant outlet communicating with the
outlet header chamber as in the heat exchanger described in par.
25), the refrigerant flows through the heat exchange tubes of the
tube groups markedly unevenly, whereas even in this case, the
refrigerant flow through the heat exchange tubes can be made
uniform if the heat exchanger has the feature described in any one
of par. 16) to 23).
[0052] The heat exchangers described in par. 26) to 28) have a
refrigerant dam portion which offers resistance to the refrigerant
flowing from the first space of the inlet header chamber of the
refrigerant inlet-outlet tank into the first space of the
refrigerant turn tank via the corresponding heat exchange tubes.
The heat exchange tubes communicating with the inlet header chamber
of the inlet-outlet tank are therefore made uniform to a greater
extent in the quantities of refrigerant flowing therethrough.
[0053] In the heat exchanger described in par. 29), the divided
flow control plate of the refrigerant turn tank is formed
integrally with the second member of aluminum extrudate.
Accordingly, the control plate can be provided inside the turn tank
by a facilitated procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 is a perspective view showing the overall
construction of a first embodiment of evaporator according to the
invention. FIG. 2 is a view in vertical section partly broken away
and showing the evaporator of FIG. 1 as it is seen from behind.
FIG. 3 is a view in section taken along the line A-A in FIG. 2.
FIG. 4 is an enlarged view in section taken along the line B-B in
FIG. 2 and partly broken away. FIG. 5 is an enlarged view in
section taken along the line C-C in FIG. 2 and partly broken away.
FIG. 6 is an exploded perspective view of a refrigerant
inlet-outlet tank of the evaporator of FIG. 1. FIG. 7 is an
exploded perspective view of a refrigerant turn tank of the
evaporator of FIG. 1. FIG. 8 is a diagram showing how a refrigerant
flows through the evaporator of FIG. 1. FIG. 9 is a view
corresponding to FIG. 8 and showing a second embodiment of
evaporator according to the invention. FIG. 10 is a view
corresponding to FIG. 8 and showing a third embodiment of
evaporator according to the invention. FIG. 11 is a view
corresponding to FIG. 8 and showing a fourth embodiment of
evaporator according to the invention. FIG. 12 is a view
corresponding to FIG. 8 and showing a fifth embodiment of
evaporator according to the invention. FIG. 13 is a view
corresponding to FIG. 2 and showing a sixth embodiment of
evaporator according to the invention. FIG. 14 is a view in
horizontal section of a refrigerant inlet-outlet tank showing a
seventh embodiment of evaporator according to the invention. FIG.
15 is an enlarged view in section taken along the line D-D in FIG.
14 and partly broken away. FIG. 16 is an exploded perspective view
of a refrigerant inlet-outlet tank of the evaporator of the seventh
embodiment. FIG. 17 is an exploded perspective view of a
refrigerant turn tank of the evaporator of the seventh embodiment.
FIG. 18 is a diagram showing how a refrigerant flows through the
evaporator of the seventh embodiment. FIG. 19 is a diagram
corresponding to FIG. 18 and showing an eighth embodiment of
evaporator according to the invention. FIG. 20 is an enlarged
fragmentary view in vertical section showing a ninth embodiment of
evaporator according to the invention.
BEST MODE OF CARRYING OUT THE INVENTION
[0055] Embodiments of the present invention will be described below
with reference to the drawings. These embodiments are evaporators
according to the invention.
[0056] In the following description, the upper, lower, left- and
right-hand sides of FIGS. 1, 2 and 13 will be referred to
respectively as the "upper," "lower," "left" and "right," the
downstream side of the flow of air through an air passing clearance
between each adjacent pair of heat exchange tubes (i.e., the
direction indicated by the arrow X in FIG. 1, and the right-hand
side of FIGS. 4, 5 and 15) will be referred to as "front," and the
opposite side as "rear." Further throughout all the drawings, like
parts will be designated by like reference numerals and will not be
described repeatedly.
[0057] FIGS. 1 to 5 show the overall construction of an evaporator
as a first embodiment of the invention, FIGS. 6 and 7 show the
construction of main portions, and FIG. 8 shows how a refrigerant
flows through the evaporator of the first embodiment.
[0058] With reference to FIGS. 1 to 3, the evaporator 1 comprises a
refrigerant inlet-outlet aluminum tank 2 and a refrigerant turn
aluminum tank 3 which are arranged as spaced apart vertically, tube
groups 5 in the form of a plurality of rows, i.e., two rows in the
present embodiment, as spaced forwardly or rearwardly of the
evaporator between the two tanks 2, 3 and each comprising a
plurality of heat exchange aluminum tubes 4, i.e., at least seven
heat exchange aluminum tubes 4, arranged in parallel at a spacing
leftwardly or rightwardly, i.e., laterally, of the evaporator,
corrugated aluminum fins 6 arranged respectively in air passing
clearances between adjacent pairs of heat exchange tubes 4 of each
tube group 5 and also outside the heat exchange tubes 4 at the left
and right opposite ends of each tube group 5 and each brazed to the
heat exchange tube 4 adjacent thereto, and an aluminum side plate 7
disposed outside the corrugated fin 6 at each of the left and right
ends.
[0059] With reference to FIGS. 4 to 6, the refrigerant inlet-outlet
tank 2 comprises a platelike first member 8 made of aluminum
brazing sheet having a brazing material layer at least over the
outer surface (lower surface) thereof and having the heat exchange
tubes 4 joined thereto, a second member 9 of bare aluminum
extrudate and covering the upper side of the first member 8, and
aluminum caps 11, 12 closing respective left and right end
openings. The tank 2 comprises a refrigerant inlet header chamber
13 positioned on the front side and a refrigerant outlet header
chamber 14 positioned on the rear side.
[0060] The first member 8 has at each of the front and rear side
portions thereof a curved portion 15 in the form of a circular arc
of small curvature in cross section and bulging downward at its
midportion. The curved portion 15 has a plurality of tube insertion
slits 16 elongated forward or rearward and arranged at a spacing in
the lateral direction. Each corresponding pair of slits 16 in the
front and rear curved portions 15 are in the same position with
respect to the lateral direction. The front edge of the front
curved portion 15 and the rear edge of the rear curved portion 15
are integrally provided with respective upstanding walls 17
extending over the entire length of the member 8. The first member
8 includes between the two curved portions 15 a flat portion 18
having a plurality of through holes 19 arranged at a spacing in the
lateral direction.
[0061] The second member 9 is generally m-shaped in cross section
and opened downward and comprises front and rear two walls 21, 22
extending laterally, a partition wall 23 provided in the midportion
between the two walls 21, 22 and extending laterally to divide the
interior of the refrigerant inlet-outlet tank 2 into front and rear
two spaces, and two generally circular-arc connecting walls 24
bulging upward and integrally connecting the partition wall 23 to
the respective front and rear walls 21, 22 at their upper ends. The
rear wall 22 and the partition wall 23 are integrally
interconnected at their lower ends by a partition plate 25 over the
entire length of the member 9. Alternatively, a plate separate from
the rear wall 22 and the partition wall 23 may be secured to these
walls 22, 23 as the plate 25. The partition plate 25 has laterally
elongated refrigerant passing holes 26, 26A formed therein at a
rear portion thereof other than the left and right end portions of
the plate and arranged at a spacing laterally thereof. The
refrigerant passing hole 26A in the lateral midportion of the plate
25 has a length smaller than the spacing between adjacent heat
exchange tubes 4 of the rear tube group 5, and is formed between
the adjacent two heat exchange tubes 4 in the lateral middle of the
rear tube group 5. The other refrigerant passing holes 26 have a
larger length than the hole 26A. The partition plate 25 is provided
at a rear edge portion of its lower surface with a downwardly
projecting ridge 25a integral therewith and extending over the
entire length thereof. The front wall 21 is integrally provided at
the lower edge of its inner surface with a ridge 21a projecting
downward. The partition wall 23 has a lower end projecting downward
beyond the lower ends of the ridges 21a, 25a and integrally
provided with a plurality of projections 23a fitted into the
through holes 19 of the first member 8, these projections 23a
projecting downward from the lower edge of the wall 23 and arranged
at a spacing in the lateral direction. The projections 23a are
formed by cutting away specified portions of the partition wall
23.
[0062] The caps 11, 12 are made from a bare material as by press
work, forging or cutting, each have a recess facing laterally
inward for the corresponding ends of the first and second members
8, 9 to fit in. The right cap 12 has a refrigerant inflow opening
12a in communication with the refrigerant inlet header chamber 13,
and a refrigerant outflow opening 12b communicating with the upper
portion of the refrigerant outlet header chamber 14 above the
partition plate 25. Brazed to the right cap 12 is a refrigerant
inlet-outlet aluminum member 27 having a refrigerant inlet 27a
communicating with the refrigerant inflow opening 12a and a
refrigerant outlet 27b communicating with the refrigerant outflow
opening 12b.
[0063] The two members 8, 9 are brazed to each other utilizing the
brazing material layer of the first member 8, with the projections
23a of the second member 9 inserted in the respective holes 19 of
the first member 8 in crimping engagement and with the upstanding
walls 17 of the first member 8 engaged with the ridges 21a, 25a of
the second member 9. The refrigerant inlet-outlet tank 2 is formed
by brazing the two caps 11, 12 to the first and second members 8, 9
using a brazing material sheet. The portion of the tank 2 forwardly
of the partition wall 23 of the second member 9 serves as the
refrigerant inlet header chamber 13, and the portion thereof
rearward from the partition wall 23 as the refrigerant outlet
header chamber 14. Furthermore, the refrigerant outlet header
chamber 14 is divided into upper and lower two spaces 14a, 14b by
the partition plate 25, and these spaces 14a, 14b are in
communication through the refrigerant passing holes 26, 26A. The
lower space 14b is a first space in communication with the heat
exchange tubes 4 of the rear tube group 5, and the upper space 14a
a second space via which the refrigerant flows out of the
evaporator. The refrigerant outflow opening 12b of the right cap 12
is in communication with the upper space 14a of the refrigerant
outlet header chamber 14.
[0064] With reference to FIGS. 4, 5 and 7, the refrigerant turn
tank 3 comprises a platelike first member 28 made of aluminum
brazing sheet having a brazing material layer at least over the
outer surface (upper surface) thereof and having the heat exchange
tubes 4 joined thereto, a second member 29 made of bare aluminum
extrudate and covering the lower side of the first member 28, and
aluminum caps 31 for closing left and right opposite end openings.
The tank 3 comprises a refrigerant inflow header chamber 32 as a
space positioned on the front side and a refrigerant outflow header
chamber 33 as a space positioned on the rear side.
[0065] The refrigerant turn tank 3 has a top surface 3a, front and
rear opposite side surfaces 3b and a bottom surface 3c. The top
surface 3a of the refrigerant turn tank 3 is circular-arc in cross
section in its entirety such that the midportion thereof with
respect to the forward or rearward direction is the highest portion
34 which is gradually lowered toward the front and rear sides. The
tank 3 is provided in its front an rear opposite side portions with
grooves 35 extending from the front and rear opposite sides of the
highest portion 35 of the top surface 3a to the front and rear
opposite side surfaces 3b, respectively, and arranged laterally at
a spacing. Each groove 35 has a flat bottom face. Each groove 35
has a first portion 35a existing on the top surface 3a of the tank
3 and having the same depth over the entire length of this portion.
Opposite side faces defining the first portion 35a of the groove 35
are inclined upwardly outward away from each other laterally of the
tank 3, and the width of the first portion 35a of the groove 35
gradually increases from the bottom of the groove toward the
opening thereof. Further in the longitudinal section of each groove
35, the bottom face of the first portion 35a is shaped in the form
of a circular arc extending from the highest portion (34) side of
the tank top surface 3a forwardly or rearwardly outward as curved
downward.
[0066] The groove 35 has a second portion 35b existing at the
junction 3d of the top surface 3a of the refrigerant turn tank 3
and the front or rear side surface 3b thereof and having a bottom
face which is inclined downward forwardly or rearwardly outward.
The bottom face of the second portion 35b extends from the end of
the bottom face of the first portion 35a. Each groove 35 has a
third portion 29c existing on the front or rear side surface 3b of
the tank 3 and having a vertical bottom face. The groove third
portion 35c has the same width from the bottom of the groove 35 to
the opening thereof.
[0067] The first member 28 has a circular-arc cross section bulging
upward at its midportion with respect to the forward or rearward
direction and is provided with a depending wall 28a formed at each
of the front and rear side edges thereof integrally therewith and
extending over the entire length of the member 28. The upper
surface of the first member 28 serves as the top surface 3a of the
refrigerant turn tank 3, and the outer surface of the depending
wall 28a as the front or rear side surface 3b of the tank 3. The
grooves 35 are formed in each of the front and rear side portions
of the first member 28 and extend from the highest portion 34 in
the midportion of the member 28 with respect to the forward or
rearward direction to the lower end of the depending wall 28a. In
each of the front and rear side portions of the first member 28
other than the highest portion 34 in the midportion thereof, tube
insertion slits 36 elongated in the forward or rearward direction
are formed between respective adjacent pairs of grooves 35. Each
corresponding pair of front and rear tube insertion slits 36 are in
the same position with respect to the lateral direction. The first
member 28 has a plurality of through holes 37 formed in the highest
portion 34 in the midportion thereof and arranged laterally at a
spacing. The depending walls 28a, grooves 35, tube insertions slits
36 and through holes 37 of the first member 28 are formed at the
same time by making the member 28 from an aluminum brazing sheet by
press work.
[0068] The second member 29 is generally w-shaped in cross section
and opened upward, and comprises front and rear two walls 38, 39
curved upwardly outwardly forward and rearward, respectively, and
extending laterally, a vertical partition wall 41 dividing the
interior of the refrigerant turn tank 3 into front and rear two
spaces, and two connecting walls 42 integrally connecting the
partition wall 41 to the respective front and rear walls 38, 39 at
their lower ends. The outer surfaces of the connecting walls 42
provide the bottom surface 3c of the tank 3, and the outer surfaces
of the front and rear walls 38, 39 each provide a junction 3e of
the bottom surface 3c and the front or rear side surface 3b . The
front and rear walls 38, 39 have respective ridges 38a, 39a each
projecting upward from the inner edge of the upper end thereof and
extending over the entire length of the wall.
[0069] The partition wall 41 has an upper end projecting upward
beyond the upper ends of the front and rear walls 38, 39, and is
provided with a plurality of projections 41a projecting upward from
the upper edge of the wall 41 integrally therewith, arranged
laterally at a spacing and to be fitted into the respective through
holes 37 in the first member 28. The partition wall 41 is provided,
at a portion thereof slightly leftwardly of its midportion, with
refrigerant passing cutouts 41b formed in the upper edge thereof
between respective adjacent pairs of projections 41a. The
projections 41a and the cutouts 41b are formed by cutting away
specified portions of the partition wall 41.
[0070] The caps 31 are made from a bare material as by press work,
forging or cutting, and each have a recess facing laterally inward
for the corresponding ends of the first and second members 28, 29
to fit in.
[0071] The first and second members 28, 29 are brazed to each other
utilizing the brazing material layer of the first member 28, with
the projections 41a of the second member 29 inserted through the
respective holes 37 in crimping engagement and with the depending
walls 28a of the first member 28 engaged with the ridges 38a, 39a
of the second member 29. The two caps 31 are further brazed to the
first and second members 28, 29 using a brazing material sheet,
whereby the refrigerant turn tank 3 is formed. The upper-end
openings of the cutouts 41b in the partition wall 41 of the second
member 29 are closed with the first member 28, whereby refrigerant
passing holes 43 are formed. The refrigerant passing holes 43,
which are formed by closing the upper-end openings of the cutouts
41b in the partition wall 41 with the first member 28, can
alternatively be through holes formed in the partition wall 41. The
partition wall 41 of the second member 29 serves as a divided flow
control plate 44 which has the refrigerant passing holes 43 and
which functions as a uniformalizing member dividing the refrigerant
turn tank 3 into the refrigerant inflow header chamber 32 on the
front side and the refrigerant outflow header chamber 33 on the
rear side for causing the refrigerant to flow as uniformly
divided.
[0072] The divided flow control plate 44 is provided at its left
and right opposite end portions with respective refrigerant dam
portions 45A, 45B having no refrigerant passing holes 43 and each
extending from the corresponding end of the plate 44 over a
predetermined length. Between the dam portions 45A, 45B, the plate
44 has a refrigerant passing portion 46 provided with one or at
least two refrigerant passing holes 43, i.e., at least two
refrigerant passing holes 43 in this embodiment. The dam portion
45B at the right has a length which is greater than that of the dam
portion 45A at the left and approximately one-half of the entire
length of the control plate 44. It is desired that the length of
each of the dam portions 45A, 45B be at least 15% of the entire
length of the control plate 44, and that the combined area of all
the refrigerant passing holes 43 formed in the refrigerant passing
portion 46 be 130 to 510 mm.sup.2. Preferably, the length of each
of the refrigerant dam portions 45A, 45B is limited to not greater
than 78% of the entire length of the control plate 44 if largest.
The ratio of the number of refrigerant passing holes 43 in the
refrigerant passing portion 46 to the number of heat exchange tubes
4 of each tube group 5, i.e., the opening ratio, is preferably 20
to 75%. If the length of each dam portion 45A or 45B is less than
15% of the entire length of the divided flow control plate 44, it
is likely that all the heat exchange tubes 4 of each tube group
will not be fully uniform in the amount of flow of the refrigerant
therethrough. Further if the combined area of all the refrigerant
passing holes 43 in the refrigerant passing portion 46 is less than
130 mm.sup.2, greatly increased channel resistance will be offered
to result in adversely affected performance, whereas if the
combined area is in excess of 510 mm.sup.2, there is the likelihood
that the control plate 44 will be unable to serve the divided flow
control function. If the opening ratio, i.e., the ratio of the
number of refrigerant passing holes 43 in the refrigerant passing
portion 46 to the number of heat exchange tubes 4 of each tube
group 5, is less than 20%, greatly increased channel resistance
will be encountered to entail adversely affected performance. If
the ratio is over 75%, it is likely that no divided flow control
function will be available.
[0073] The heat exchange tubes 4 providing the front and rear tube
groups 5 are each made of a bare material in the form of an
aluminum extrudate. Each tube 4 is flat, has a large width in the
forward or rearward direction and is provided in its interior with
a plurality of refrigerant channels 4a extending longitudinally of
the tube and arranged in parallel. The tube 4 has front and rear
opposite end walls which are each in the form of an outwardly
bulging circular arc. Each corresponding pair of heat exchange tube
4 of the front tube group 5 and heat exchange tube 4 of the rear
tube group 5 are in the same position with respect to the lateral
direction. Each heat exchange tube 4 has its upper end inserted
into the tube insertion slit 16 of the first member 8 of the
inlet-outlet tank 2 and brazed to the first member 8 utilizing the
brazing material layer of the member 8, and has its lower end
inserted into the tube insertion slit 36 of the first member 28 of
the turn tank 3 and brazed to the first member 28 utilizing the
brazing material layer of the member 28.
[0074] Preferably, the heat exchange tube 4 is 0.75 to 1.5 mm in
height, i.e., in thickness in the lateral direction, 12 to 18 mm in
width in the forward or rearward direction, 0.175 to 0.275 mm in
the wall thickness of the peripheral wall thereof, 0.175 to 0.275
mm in the thickness of partition walls separating refrigerant
channels 4a from one another, 0.5 to 3.0 mm in the pitch of
partition walls, and 0.35 to 0.75 mm in the radius of curvature of
the outer surfaces of the front and rear opposite end walls.
[0075] In place of the heat exchange tube 4 of aluminum extrudate,
an electric resistance welded tube of aluminum may be used which
has a plurality of refrigerant channels formed therein by inserting
inner fins into the tube. Also usable is a tube which is made from
a plate prepared from an aluminum brazing sheet having an aluminum
brazing material layer on opposite sides thereof by rolling work
and which comprises two flat wall forming portions joined by a
connecting portion, a side wall forming portion formed on each flat
wall forming portion integrally therewith and projecting from one
side edge thereof opposite to the connecting portion, and a
plurality of partition forming portions projecting from each
flatwall forming portion integrally therewith and arranged at a
spacing widthwise thereof, by bending the plate into the shape of a
hairpin at the connecting portion and brazing the side wall forming
portions to each other in butting relation to form partition walls
by the partition forming portions. The corrugated fins to be used
in this case are those made from a bare material.
[0076] The corrugated fin 6 is made from an aluminum brazing sheet
having a brazing material layer on opposite sides thereof by
shaping the sheet into a wavy form. Louvers 6a are formed as
arranged in parallel in the forward or rearward direction in the
portions of the wavy sheet which connect crest portions thereof to
furrow portions thereof. The corrugated fins 6 are used in common
for the front and rear tube groups 5. The width of the fin 6 in the
forward or rearward direction is approximately equal to the
distance from the front edge of the heat exchange tube 4 in the
front tube group 5 to the rear edge of the corresponding heat
exchange tube 4 in the rear tube group 5. It is desired that the
corrugated fin 6 be 7.0 mm to 10.0 mm in fin height, i.e., the
straight distance from the crest portion to the furrow portion, and
1.3 to 1.8 mm in fin pitch, i.e., the pitch of connecting
portions.
[0077] The evaporator 1 is fabricated by tacking the components
together in combination and collectively brazing the tacked
assembly.
[0078] Along with a compressor, a condenser and pressure reduction
means, the evaporator 1 constitutes a refrigeration cycle, which is
installed in vehicles, for example, in motor vehicles for use as an
air conditioner.
[0079] With reference to FIG. 8 showing the evaporator 1 described,
a two-layer refrigerant of vapor-liquid mixture phase flowing
through a compressor, condenser and pressure reduction means enters
the refrigerant inlet header chamber 13 of the refrigerant
inlet-outlet tank 2 via the refrigerant inlet 27a of the
refrigerant inlet-outlet member 27 and the refrigerant inflow
opening 12a of the right cap 12.
[0080] The refrigerant admitted into the inlet header chamber 13
tends to readily flow into the heat exchange tubes 4 closer to the
left and right opposite ends of the front tube group 5, whereas
since the divided flow control plate 44 of the refrigerant turn
tank 3 has the refrigerant dam portions 45A, 45B at its opposite
ends, these dam portions offer resistance to the refrigerant to be
passed through the heat exchange tubes 4 closer to the left and
right ends, permitting the refrigerant to flow as uniformly divided
into the tubes 4, flow down the refrigerant channels 4a therein and
ingress into the refrigerant inflow header chamber 32 of the
refrigerant turn tank 3.
[0081] The refrigerant then flows into the refrigerant outflow
header chamber 33 through the refrigerant passing holes 43 of the
refrigerant passing portion 46, dividedly moves into the
refrigerant channels 4a of all the heat exchange tubes 4 of the
rear tube group 5, changes its course and passes upward through the
channels 4a into the lower space 14b of the refrigerant outlet
header chamber 14 of the refrigerant inlet-outlet tank 2. The
partition plate 25 provided in the outlet header chamber 14 gives
resistance to the flow of refrigerant, consequently enabling the
refrigerant to flow as uniformly divided from the outflow header
chamber 33 into the tubes 4 of the rear tube group 5 and also to
flow from the inlet header chamber 13 into the tubes 4 of the front
tube group 5. As a result, the refrigerant flows through the heat
exchange tubes 4 of the two tube groups in uniform quantities.
[0082] Subsequently, the refrigerant flows through the refrigerant
passing holes 26, 26A of the partition plate 25 into the upper
space 14a of the outlet header chamber 14 and flows out of the
evaporator via the refrigerant outflow opening 12b of the cap 12
and the outlet 27b of the refrigerant inlet-outlet member 27. While
flowing through the refrigerant channels 4a of the heat exchange
tubes 4 of the front tube group 5 and the refrigerant channels 4a
of the heat exchange tubes 4 of the rear tube group 5, the
refrigerant is subjected to heat exchange with air flowing through
the air passing clearances in the direction of arrow X shown in
FIG. 1 and flows out of the evaporator in a vapor phase.
[0083] At this time, water condensate is produced on the surfaces
of the corrugated fins 6, and the condensate flows down the top
surface 3a of the turn tank 3. The condensate flowing down the tank
top surface 3a enters the first portions 35a of the grooves 35 by
virtue of a capillary effect, flows through the grooves 35 and
falls off the lower ends of the groove third portions 35c to below
the turn tank 3. This prevents a large quantity of condensate from
collecting between the top surface 3a of the turn tank 3 and the
lower ends of the corrugated fins 6, consequently preventing the
condensate from freezing due to the collection of large quantity of
the condensate, whereby inefficient performance of the evaporator 1
is precluded.
[0084] According to the first embodiment, the divided flow control
plate 44 has the refrigerant passing holes 43 and divides the
refrigerant turn tank 3 into the refrigerant inflow header chamber
32 on the front side and the refrigerant outflow header chamber 33
on the rear side to serve as a uniformalizing member for causing
the refrigerant to flow as uniformly divided through the heat
exchange tubes 4 of the front tube group 5 in communication with
the inlet header chamber 13. However, this construction is not
limitative but can be modified suitably.
[0085] FIG. 9 shows a second embodiment of evaporator according to
the invention.
[0086] In the case of the embodiment shown in FIG. 9, the divided
flow control plate 44 within the refrigerant turn tank 3 has a
refrigerant passing portion 46 at the lateral midportion thereof,
and refrigerant dam portions 45A, 45B provided respectively on the
left and right sides of this portion 46 and approximately equal in
length. This embodiment is the same as the first embodiment with
respect to the ratio of the length of each of the dam portions 45A,
45B to the entire length of the control plate 44, the combined area
of all the refrigerant passing holes 43 formed in the refrigerant
passing portion 46, and the opening ratio which is the ratio of the
number of refrigerant passing holes 43 formed in the refrigerant
passing portion 46 to the number of heat exchange tubes 4 in each
tube group 5. The partition plate 25 of the refrigerant
inlet-outlet tank 2 has a plurality of laterally elongated
refrigerant passing holes 50 arranged laterally at a spacing and
formed at the portions thereof corresponding to the respective dam
portions 45A, 45B of the divided flow control plate 44. All the
refrigerant passing holes 50 are equal in length. The second
embodiment is the same as the first with the exception of these
features.
[0087] The second embodiment is also so adapted that the
refrigerant flowing through the evaporator flows through the heat
exchange tubes 4 of each tube group in uniform quantities.
[0088] FIG. 10 shows a third embodiment of evaporator according to
the invention.
[0089] In the case of the embodiment shown in FIG. 10, the divided
flow control plate 44 within the refrigerant turn tank 3 has a
refrigerant passing portion 46 slightly longer than in the first
embodiment and positioned leftwardly of the lateral midportion
thereof, and refrigerant dam portions 45A, 45B provided
respectively on the left and right sides of this portion 46. The
dam portion 45B at the right has a length greater than that of the
dam portion 45A at the left and approximately one-half of the
entire length of the control plate 44. This -embodiment is the same
as the first embodiment with respect to the ratio of the length of
each of the dam portions 45A, 45B to the entire length of the
control plate 44, the combined area of all the refrigerant passing
holes 43 formed in the refrigerant passing portion 46, and the
opening ratio which is the ratio of the number of refrigerant
passing holes 43 formed in the refrigerant passing portion 46 to
the number of heat exchange tubes 4 in each tube group 5. The
partition plate 25 of the refrigerant inlet-outlet tank 2 has one
laterally elongated refrigerant passing hole 51 formed at the
portion thereof corresponding to the left dam portion 45A of the
control plate 44, and a plurality of laterally elongated
refrigerant passing holes 51 arranged laterally at a spacing and
formed at the portion thereof corresponding to the right dam
portion 45B. All the refrigerant passing holes 51 are equal in
length. The third embodiment is the same as the first with the
exception of these features.
[0090] The third embodiment is also so adapted that the refrigerant
flowing through the evaporator flows through the heat exchange
tubes 4 of each tube group in uniform quantities.
[0091] FIG. 11 shows a fourth embodiment of evaporator according to
the invention.
[0092] In the case of the embodiment shown in FIG. 11, the divided
flow control plate 44 within the refrigerant turn tank 3 has an
auxiliary refrigerant passing hole 60 formed in at least one of the
two refrigerant dam portions 45A, 45B, i.e., in each of these dam
portions 45A, 45B according to the present embodiment. The fourth
embodiment is the same as the first with the exception of this
feature. Also in the second and third embodiments, an auxiliary
refrigerant passing hole may be formed in at least one of the two
dam portions 45A, 45B.
[0093] The fourth embodiment is also so adapted that the
refrigerant flowing through the evaporator flows through the heat
exchange tubes 4 of each tube group in uniform quantities.
[0094] FIG. 12 shows a fifth embodiment of evaporator according to
the invention.
[0095] In the case of the embodiment shown in FIG. 12, an
evaporator 61 has a refrigerant inlet-outlet tank 32 and a
refrigerant turn tank 3 which are made to extend rightward over a
larger distance than is the case with the first embodiment.
Provided between these extensions 2A, 3A are tube groups 5 in the
form of front and rear two rows and each comprising a plurality of
heat exchange tubes arranged in parallel at a spacing in the
lateral direction. The front and rear tube groups 5 have their heat
exchange tubes 4 joined at the tube upper ends to the respective
front and rear opposite side portions of the extensions 2A of the
tank 2 and at the tube lower ends to the respective front and rear
opposite side portions of the extensions 3A of the tank 3.
[0096] The outlet header chamber 14 of the refrigerant inlet-outlet
tank 2 has no partition plate. The extension 2A of the tank 2 has
right-end openings which are closed with a cap (not shown) having
no refrigerant inflow opening and no refrigerant outflow opening.
The two header chambers 32, 33 of the refrigerant turn tank 3 are
separated from the extensions 32A, 33A of these chambers 32, 33 by
a partition plate 62. The extension 3A of the tank 3 has right-end
openings which are closed with a cap (not shown) having a
refrigerant inflow opening and a refrigerant outflow opening.
Brazed to this cap is a refrigerant inlet-outlet member (not shown)
having a refrigerant inlet in communication with the inflow opening
and a refrigerant outlet in communication with the outflow opening.
The fifth embodiment is the same as the first with the exception of
these features. The first to fourth embodiments can also be given
the same construction as the fifth embodiment.
[0097] A two-layer refrigerant of vapor-liquid mixture phase
flowing through a compressor, condenser and pressure reduction
means enters the evaporator 61, more specifically, the extension
32A of the refrigerant inflow header chamber 32 of the refrigerant
turn tank 3 via the refrigerant inlet of the refrigerant
inlet-outlet member and the refrigerant inflow opening of the right
cap.
[0098] The refrigerant admitted into the extension 32A flows upward
through the refrigerant channels 4a of heat exchange tubes 4 of the
front tube group 5 joined to the extension 3A, flows into the
refrigerant inlet header chamber 13 and flows leftward through this
chamber 13. As in the case of the first embodiment, the refrigerant
thereafter flows as uniformly divided into the heat exchange tubes
4 of the front tube group 5, flows down the refrigerant channels 4a
therein and ingresses into the refrigerant inflow header chamber 32
of the refrigerant turn tank 3.
[0099] The refrigerant then flows into the refrigerant outflow
header chamber 33 through the refrigerant passing holes 43 of the
refrigerant passing portion 46, dividedly moves into the
refrigerant channels 4a of all the heat exchange tubes 4 of the
rear tube group 5, changes its course and passes upward through the
channels 4a into the refrigerant outlet header chamber 14 of the
refrigerant inlet-outlet tank 2. Subsequently, the refrigerant
flows rightward through the outlet header chamber 14, enters the
channels 4a of heat exchange tubes 4 of the rear tube group 5
joined to the extension 2A, flows down the channels 4a into the
extension 33A of the outflow header chamber 33 of the turn tank 3
and flows out of the evaporator through the refrigerant outflow
opening of the cap and the outlet of the inlet-outlet member.
[0100] The fifth embodiment is also so adapted that the refrigerant
flowing through the evaporator flows through the heat exchange
tubes 4 of each tube group in uniform quantities.
[0101] FIG. 13 shows a sixth embodiment of evaporator according to
the invention.
[0102] In the case of the embodiment shown in FIG. 13, the
refrigerant passing holes 43 formed in the divided flow control
plate 44 are positioned as shifted from heat exchange tubes 4.
Stated more specifically, each refrigerant passing hole 43 is
positioned between a pair of adjacent heat exchange tubes 4. With
the exception of this feature, the sixth embodiment is the same as
the first. Incidentally, the second to fifth embodiments can be
made to have the same construction as the sixth embodiment.
[0103] FIGS. 14 to 18 show a seventh embodiment of evaporator
according to the invention.
[0104] In the case of the embodiment shown in FIGS. 14 to 18, the
front wall 21 and the partition wall 23 of the second member 9 of
the refrigerant inlet-outlet tank 2 are connected together at their
lower ends by a flow dividing resistance plate 70 over the entire
length of the tank. The resistance plate 70 has one refrigerant
passing circular hole 71 formed at the midportion thereof with
respect to the lateral direction. Alternatively, the resistance
plate 70 may be a plate separate from the front wall 21 and the
partition wall 23 and fixed to the front wall 21, rear wall 22 and
partition wall 23. The refrigerant inlet header chamber 13 is
divided by the resistance plate 70 into upper and lower two spaces
13a, 13b, which are held in communication with each other through
the circular hole 71. The lower space 13b is a first space which is
in communication with the heat exchange tubes 4 of the front tube
group 5, and the upper space 13a is a second space for the
refrigerant to flow in. The refrigerant inflow opening 12a of the
right cap 12 is in communication with the upper space 13a of the
inlet header chamber 13.
[0105] The refrigerant passing circular hole 71 of the flow
dividing resistance plate 70 is positioned between the two heat
exchange tubes 4 in the lateral center of the front tube group 5.
The circular hole 71 has a lateral size (diameter) which is smaller
than the spacing between the two tubes 4. Preferably, the hole 71
is 3 to 8 mm in diameter. If the hole 71 is less than 3 mm in
diameter, increased channel resistance will be offered to the
refrigerant to burden the air conditioner system with an increased
load, while the flow of refrigerant produces a greater noise due to
an increased flow velocity. If the diameter of the hole 71 is in
excess of 8 mm, an increased quantity of refrigerant flows through
the midportion, further entailing the likelihood that the
refrigerant will encounter difficulty in spreading over the entire
area of lower space 13b to be described below of the inlet header
chamber 13. The refrigerant passing circular hole 71 has an area
greater than the combined cross sectional area of refrigerant
channels of one heat exchange tube 4. The refrigerant passing hole
to be formed in the flow dividing resistance plate 70 is not
limited to the circular shape but may have a suitably altered
shape, such as an elliptical form (not limited to a mathematically
defined elliptical form but including forms which are nearly
elliptical). Even when the refrigerant passing hole has a shape
other than the circular, the hole should have the above-mentioned
area and is so sized as to be positioned between the two heat
exchange tubes in the lateral midportion of the tube group 5.
[0106] With reference to FIG. 17, the divided flow control plate 44
of the refrigerant turn tank 3 has a refrigerant dam portion 72
having no refrigerant passing holes and formed at the longitudinal
midportion thereof, i.e., at a position corresponding to the
refrigerant passing circular hole 71 of the flow dividing
resistance plate 70 of the inlet-outlet tank 2. The control plate
44 also has a refrigerant passing portion 73 formed on each of the
left and right sides of the dam portion 72 and having one or at
least two refrigerant passing holes 43, i.e, at least two holes 43
in the present embodiment. Preferably, the dam portion 72 has a
length-of at least 28 mm in the lateral direction. If the length is
less than 28 mm, it is likely that an increased amount of
refrigerant will flow through the midportion. Further preferably,
the ratio of the number of refrigerant passing holes 43 in each
refrigerant passing portion 73 to the number of heat exchange tubes
4 of each tube group 5, i.e., the opening ratio, is 20 to 90%. If
this ratio is less than 20%, increased channel resistance will be
offered to the refrigerant, possibly resulting in impaired
performance. When the ratio is in excess of 90%, it is likely that
no divided flow control function will be available.
[0107] The seventh embodiment is the same as the first with the
exception of the above features.
[0108] With reference to FIG. 18 showing the evaporator 1 of the
seventh embodiment, a two-layer refrigerant of vapor-liquid mixture
phase flowing through a compressor, condenser and pressure
reduction means enters the upper space 13a of the refrigerant inlet
header chamber 13 of the refrigerant inlet-outlet tank 2 via the
refrigerant inlet 27a of the refrigerant inlet-outlet member 27 and
the refrigerant inflow opening 12a of the right cap 12, flows into
the lower space 13b through the single circular hole 71 in the flow
dividing resistance plate 70 and further flows from the lower space
13b dividedly into the refrigerant channels 4a of all the heat
exchange tubes 4 of the front tube group 5. Since the resistance
plate 70 has the single refrigerant passing circular hole 71 only
formed therein, the refrigerant gently flows into the lower space
13b, spreads over the entire area of this space 13b to flow into
the refrigerant channels 4a of all the heat exchange tubes 4. This
permits the refrigerant to flow through these tube 4 in uniform
quantities.
[0109] The refrigerant flowing into the channels 4a of all the heat
exchange tubes 4 flows down the channels 4a into the refrigerant
inflow header chamber 32 of the refrigerant turn tank 3. The
refrigerant admitted into the chamber 32 flows leftwardly and
righwardly outward by virtue of the function of the dam portion 72
and flows into the refrigerant outflow header chamber 33 through
the holes 43 of the refrigerant passing portions 73. The resistance
offered by the dam portion 73 to the flow of refrigerant inhibits
the refrigerant from flowing out of the lower space 13b of the
header chamber 13 only into the channels 4a of the heat exchange
tubes 4 of the front tube group 5 which tubes are positioned in the
vicinity of the circular holes 71, while promoting the flow of
refrigerant into the channels 4a of the other heat exchange tubes.
Thus, the refrigerant is made to flow through the heat exchange
tubes 4 of the front tube group 5 in uniform quantities.
[0110] The refrigerant flowing into the outflow header chamber 33
dividedly flows into the refrigerant channels 4a of all the heat
exchange tubes 4 of the rear tube group 5, changes its course and
passes upward through the channels 4a into the lower space 14b of
the refrigerant outlet header chamber 14 of the refrigerant
inlet-outlet tank 2. The partition plate 25 in chamber 14 gives
resistance to the flow of refrigerant, consequently enabling the
refrigerant to flow as uniformly divided from the outflow header
chamber 33 into the tubes 4 of the rear tube group 5 and also to
flow from the lower space 13b of the inlet header chamber 13 into
the heat exchange tubes 4 of the front tube group 5. As a result,
the refrigerant flows through the heat exchange tubes 4 of the two
tube groups in uniform quantities.
[0111] Subsequently, the refrigerant flows through the refrigerant
passing holes 26, 26A of the partition plate 25 into the upper
space 14a of the outlet header chamber 14 and flows out of the
evaporator via the refrigerant outflow opening 12b of the cap 12
and the outlet 27b of the refrigerant inlet-outlet member 27. While
flowing through the refrigerant channels 4a of the heat exchange
tubes 4 of the front tube group 5 and the refrigerant channels 4a
of the heat exchange tubes 4 of the rear tube group 5, the
refrigerant is subjected to heat exchange with air flowing through
the air passing clearances in the direction of arrow X shown in
FIG. 1 and flows out of the evaporator in a vapor phase.
[0112] FIG. 19 shows an eighth embodiment of evaporator according
to the invention.
[0113] In the case of the embodiment shown in FIG. 19, the
partition plate 25 of the refrigerant inlet-outlet tank 2 has a
plurality of laterally elongated refrigerant passing holes 26
arranged at a spacing in the lateral direction and formed at each
of the portions thereof corresponding to the respective refrigerant
passing portions 73 of the divided flow control plate 44. All the
refrigerant passing holes 26 are equal in length. The eighth
embodiment is the same as the seventh with the exception of this
feature.
[0114] The eighth embodiment is also so adapted that the
refrigerant flowing through the evaporator flows through the heat
exchange tubes 4 of each tube group in uniform quantities.
[0115] FIG. 20 shows a ninth embodiment of evaporator according to
the invention.
[0116] In the case of the embodiment shown in FIG. 20, the first
member 8 of the refrigerant inlet-outlet tank 2 has an upwardly
projecting ridge 75 in the form of an angle in cross section,
extending forward or rearward and positioned at the lateral
midportion thereof immediately below the center, with respect to
the lateral direction, of the refrigerant passing circular hole 7
1. The ridge 75 is formed by upwardly bending the first member 8
into a projecting ridge. In the forward or rearward direction, the
length of the ridge 75 is preferably at least equal to the diameter
(size in the forward or rearward direction) of the circular hole
71. The ridge 75 is a flow dividing member by which the refrigerant
flowing from the upper space 13a of the inlet header chamber 13
into the lower space 13b thereof through the circular hole 71 is
divided leftward and rightward within the space 13b. Incidentally,
the ridge 75 is formed simultaneously when the first member 8 is
made from an aluminum brazing sheet by press work. The ridge may be
formed by fixing a separate member to the upper surface of the
first member 8 instead of bending the first member 8 upward.
[0117] The ninth embodiment is the same as the seventh with the
exception of the above feature.
[0118] In all the foregoing embodiments, one tube group 5 is
provided between the front portions, as well as the rear portions,
of the two tanks 2, 3, but this construction is not limitative; one
or at least two tube groups 5 may be provided between the front
portions, as well as the rear portions, of the tanks 2, 3. Further
in all the foregoing embodiments, the highest portion 34 is
positioned at the midportion, with respect to the forward or
rearward direction, of the refrigerant turn tank 3, whereas this
arrangement is not limitative; the highest portion may be located
away from such midportion of the tank 3. One or at least two tube
groups are provided at each of the front and rear sides of the
highest portion also in this case. Although the refrigerant
inlet-outlet tank 2 is positioned above the refrigerant turn tank 3
which is at a lower level according to all the foregoing
embodiments, the evaporator may be used conversely with the turn
tank 3 positioned above the inlet-outlet tank 2.
INDUSTRIAL APPLICABILITY
[0119] The heat exchanger of the present invention is suitable for
use as an evaporator for motor vehicle air conditioners and is
adapted to exhibit improved heat exchange performance.
* * * * *