U.S. patent application number 11/151244 was filed with the patent office on 2006-03-16 for evaporator using micro-channel tubes.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Hong Gi Cho, Keum Nam Cho, Seong Ho Kil, Jeung Hoon Kim, Hyoung Mo Koo, Jai Kwon Lee, Baek Youn.
Application Number | 20060054310 11/151244 |
Document ID | / |
Family ID | 36605263 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060054310 |
Kind Code |
A1 |
Kim; Jeung Hoon ; et
al. |
March 16, 2006 |
Evaporator using micro-channel tubes
Abstract
An evaporator utilizes micro-channel tubes, and more
particularly, has a structure of a heat exchanger using
micro-channel tubes, which is applied to an evaporator of a
household air conditioner. The evaporator, using micro-channel
tubes, includes a plurality of heat exchanging units, each heat
exchanging unit including a plurality of the micro-channel tubes
installed between a pair of headers, and an integral header to
transmit refrigerant between the neighboring heat exchanging
units.
Inventors: |
Kim; Jeung Hoon; (Suwon-si,
KR) ; Cho; Hong Gi; (Suwon-si, KR) ; Kil;
Seong Ho; (Seongnam-si, KR) ; Cho; Keum Nam;
(Gwacheon-si, KR) ; Youn; Baek; (Suwon-si, KR)
; Koo; Hyoung Mo; (Anyang-si, KR) ; Lee; Jai
Kwon; (Suwon-si, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700
1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
36605263 |
Appl. No.: |
11/151244 |
Filed: |
June 14, 2005 |
Current U.S.
Class: |
165/110 ;
165/176 |
Current CPC
Class: |
F28D 1/05391 20130101;
F28F 9/0275 20130101; F28F 17/005 20130101; F28F 9/0204 20130101;
F25B 39/02 20130101 |
Class at
Publication: |
165/110 ;
165/176 |
International
Class: |
F28B 1/00 20060101
F28B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 15, 2004 |
KR |
2004-73993 |
Claims
1. A heat exchanging device comprising: a combining header; a
plurality of singular headers arranged horizontally in parallel
with and below the combining header; and micro-channel tubes
extending from the combining header to each singular header,
wherein the combining header transmits refrigerant from one
singular header to another singular header via the
micro-channels.
2. The heat exchanging unit according to claim 1, wherein the
combining header and the singular headers are each laid
approximately perpendicular with respect to the micro-channel
tubes.
3. The heat exchanging unit according to claim 1, wherein the
combining header is divided into a first header unit and a second
header unit, and includes a partition having openings for
communicating the refrigerant between the first header unit and the
second header unit.
4. The heat exchanging unit according to claim 3, wherein the first
and second header units are each associated with a plurality of
micro-channel tubes, and each of the first and second header units
is divided by a plurality of separators, forming the micro-channel
tubes associated with the first and second header units
respectively into a plurality of channel groups.
5. The heat exchanging unit according to claim 4, further
comprising: a plurality of heat exchanger units are defined, each
by the micro-channel tubes extending from the combining header to
one of the singular headers; connections connecting the channel
groups of one heat exchanging unit to channel groups of a
neighboring heat exchanging unit; and a plurality of refrigerant
circuits that are formed by the connections between the channel
groups.
6. The heat exchanging unit according to claim 5, wherein
refrigerant flows from upstream micro-channel tubes to downstream
micro-channel tubes, and wherein downstream micro-channel tubes
have a cross-sectional area greater than or equal to that of
upstream micro-channel tubes.
7. The heat exchanging unit according to claim 5, wherein
neighboring refrigerant circuits have flow directions that are
opposite to each other.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2004-73993, filed Sep. 15, 2004, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a heat exchanger using
micro-channel tubes, and more particularly to a structure of a heat
exchanger using micro-channel tubes, which is applied to an
evaporator of a household air conditioner.
[0004] 2. Description of the Related Art
[0005] Generally, a heat exchanger using micro-channel tubes is a
heat exchanger, in which refrigerant flows along a plurality of
tubes having a diameter of less than several mm. Such a heat
exchanger is widely used by a condenser of a vehicle air
conditioner.
[0006] Korean Patent Publication No. 1996-0009342 discloses a
structure of a heat exchanger using micro-channel tubes.
Hereinafter, with reference to FIG. 1, the heat exchanger using
micro-channel tubes will be described.
[0007] The heat exchanger using the micro-channel tubes comprises a
plurality of tubes 1 laid in a horizontal direction. The tubes 1
are vertically arranged, and corrugated pins 2 are interposed
between the tubes 1. Headers 3 and 4 for distributing refrigerant
into the tubes 1 or for collecting the refrigerant from the tubes 1
are placed at both ends of the tubes 1. The headers 3 and 4 are
made of an aluminum rod member having a circular cross-section, and
placed perpendicularly at both ends of the tubes 1. The tubes 1
communicate with the headers 3 and 4, and separators 10 and 11 for
dividing the tubes 1 into several channel groups A, B, and C are
installed in the headers 3 and 4.
[0008] The plural tubes 1 are divided into an inlet-side channel
group A, through which the refrigerant enters to the evaporator, an
outlet-side channel group C, through which the refrigerant is
discharged from the evaporator, and an intermediate channel group
B.
[0009] With reference to FIG. 2, the overall flow of the
refrigerant in the heat exchanger is described. The refrigerant
flows along all of the tubes 1 of each of the channel groups A, B,
and C in one direction, and then flows along the tubes 1 of the
next groups B and C. That is, the refrigerant, having entered into
the tubes 1 through a refrigerant inlet 6, is uniformly distributed
into all of the tubes 1 of the inlet-side channel group A, and
flows toward the upper portion of the right header 4 above the
separator 11. In the upper portion of the right header 4 above the
separator 11, the inlet-side channel group A and the intermediate
channel group B communicate with each other, the entered
refrigerant flows toward the intermediate channel group B and is
transmitted to the lower portion of the left header 3 below the
separator 10. Then, the refrigerant, having been transmitted to the
left header 3 through the intermediate channel group B, enters into
the lower portion of the right header 4 below the separator 11
through the outlet-side channel group C, and is discharged to the
outside through a refrigerant outlet 8.
[0010] Here, non-described reference numerals 7 and 9 represent
caps for closing the ends of the headers 3 and 4, and non-described
reference numerals 13 and 14 represent side plates placed on the
outer surfaces of the outermost corrugated pins 2.
[0011] In the above-described heat exchanger using micro-channel
tubes, the refrigerant in a gaseous state, having entered into the
heat exchanger through the refrigerant inlet 6, flows in each of
the tubes 1 from the inlet-side channel group A to the outlet-side
channel group C, exchanges heat with air in the tubes 1 to be
condensed to a liquid state, and the refrigerant in the liquid
state is discharged to the outside through the refrigerant outlet
8.
[0012] The heat exchanger using micro-channel tubes is called
various names, i.e., an aluminum heat exchanger due to the material
thereof, a flat tube-type heat exchanger due to the shape of the
tubes thereof, and a PFC (parallel flow condenser) due to the flow
of the refrigerant.
[0013] The heat exchanger using micro-channel tubes is advantageous
in that it has heat transfer efficiency higher than that of a pin
tube-type heat exchanger, and is miniaturized. However, the heat
exchanger using micro-channel tubes cannot be used as an evaporator
of a household air conditioner due to several problems, as
follows.
[0014] Since the evaporator exchanges heat with air of a high
temperature rather than air of the temperature thereof, moisture in
air is condensed and condensation of water occurs on the surface of
the evaporator. In the conventional heat exchanger using
micro-channel tubes, which comprises the tubes laid in the
horizontal direction, the condensed water formed on the surface of
the heat exchanger is gathered in hollow portions of the corrugated
pins between the tubes, thus decreasing heat exchanging
efficiency.
[0015] While the flow rate of air around the vehicle condenser is
comparatively rapid, such as 3.about.4 m/s, the flow rate of air
around the evaporator of the household air conditioner is
comparatively slow, such as 0.5.about.1.5 m/s, thus reducing a heat
transfer rate per unit hour. Accordingly, the conventional heat
exchanger using micro-channel tubes requires a large heat transfer
area.
[0016] While the flow of the refrigerant, flowing in the heat
exchanger, from the entrance of the refrigerant into the upper
portion of one header to the discharge of the refrigerant from the
lower portion of the other header, has an S shape, the refrigerant,
flowing in the condenser, is condensed from a gaseous state to a
liquid state, thus naturally having an S-shaped flow. As shown in
FIG. 2, the number of the tubes 1 of the outlet-side channel group
C is smaller than the number of the tubes of the inlet-side channel
group A due to the phase change of the refrigerant, thus minimizing
pressure loss in the heat exchanger. However, since the refrigerant
flowing in the evaporator is vaporized from the liquid state to the
gaseous state, it is difficult to apply the channel structure of
the condenser to the evaporator.
[0017] In spite of the above problems, several methods have been
proposed for applying the heat exchanger using micro-channel tubes
to an evaporator of a household air conditioner.
[0018] Korean Patent Laid-open No. 2003-0063980 discloses a heat
exchanger, in which headers are erected horizontally and
micro-channel tubes are laid perpendicularly between the headers.
Drain holes and line grooves for facilitating the discharge of
condensed water are formed in the heat exchanger. Korean Patent
Laid-open Nos. 2004-0017447, 2004-0017449, 2004-0017920, and
2004-0019628 disclose structures of heat exchangers for
facilitating the discharge of condensed water under the condition
that headers and micro-channel tubes are disposed in the same
manner as that of the preceding Patent.
[0019] As disclosed by the above Patents, an evaporator, in which
the headers are erected horizontally and the micro-channel tubes
are laid perpendicularly between the headers, may discharge a
sufficient quantity of the condensed water, but has disadvantages,
such as a small heat transfer area and a difficulty in achieving
uniform flow of the refrigerant.
[0020] Since the refrigerant at an inlet of the evaporator is in a
two-phase state, the refrigerant, which enters into the header of
the evaporator, cannot be uniformly distributed to the respective
tubes due to the difference of speeds of flow between the gaseous
phase and the liquid phase. Particularly, the transmission of the
refrigerant from one channel group to another channel group is
performed in one header, thus accelerating the above problems.
SUMMARY OF THE INVENTION
[0021] Therefore, in an aspect of the invention an evaporator of a
household air conditioner uses compact micro-channel tubes having a
high heat transfer efficiency.
[0022] In another aspect of the present invention, an evaporator of
a household air conditioner uses micro-channel tubes, from which
condensed water is easily discharged, and into which refrigerant is
uniformly distributed.
[0023] In accordance with one aspect of the invention, an
evaporator, uses micro-channel tubes, and comprises a plurality of
heat exchanging units, each heat exchanging unit including a
plurality of the micro-channel tubes installed between a pair of
non-integral headers, and an integral header for transmitting
refrigerant between the neighboring heat exchanging units.
[0024] The headers of each of the heat exchanging units may be laid
horizontally, and the micro-channel tubes may be erected
vertically.
[0025] The integral header may be divided into a header unit for
one heat exchanging unit and a header unit for the other heat
exchanging unit, and include a partition having openings for
communicating the refrigerant between the two header units.
[0026] Each of the headers may be divided by a plurality of
separators so that the micro-channel tubes of each of the heat
exchanging units form a plurality of channel groups.
[0027] The channel groups of one heat exchanging unit may be
connected to the channel groups of the neighboring heat exchanging
unit; and a plurality of refrigerant circuits may be formed by the
connection between the channel groups of the heat exchanging
units.
[0028] The cross-sectional areas of flow channels of a downstream
channel group may be greater than or equal to those of flow
channels of an upstream channel group.
[0029] The flow directions of the neighboring refrigerant circuits
may be opposite to each other.
[0030] In accordance with another aspect of the invention, an
evaporator, uses micro-channel tubes, and comprises a first heat
exchanging unit including a plurality of the micro-channel tubes
installed between a pair of upper and lower headers laid
horizontally, and a second heat exchanging unit, installed adjacent
to the first heat exchanging unit, including a plurality of the
micro-channel tubes installed between a pair of upper and lower
headers laid horizontally, wherein the upper header of the first
heat exchanging unit and the upper header of the second heat
exchanging unit are formed integrally with each other, thus
producing one integral upper header, and wherein the lower header
of the first heat exchanging unit and the lower header of the
second heat exchanging unit are non-integral headers.
[0031] The integral upper header may include a base, to which the
micro-channel tubes of the first and second heat exchanging units
are bonded, a cover forming a closed space together with the base,
and a partition, to divide the closed space, formed by the base and
the cover, into a first upper header unit for the first heat
exchanging unit and a second upper header unit for the second heat
exchanging unit, and including openings for communicating
refrigerant between the first and second upper header units.
[0032] Each of the integral upper header and the lower headers of
the first and second heat exchanging units may be divided by a
plurality of separators so that the micro-channel tubes of each of
the first and second heat exchanging units form a plurality of
channel groups.
[0033] One channel group of one heat exchanging unit may be
connected to the one channel group of the neighboring heat
exchanging unit; and a plurality of refrigerant circuits may be
formed by the connection between the channel groups of the heat
exchanging units.
[0034] The cross-sectional areas of flow channels of a channel
group located at an inlet of each of the refrigerant circuits,
through which the refrigerant enters into the evaporator, may be
smaller than or equal to the cross-sectional areas of flow channels
of a channel group located at an outlet of the refrigerant circuit,
through which the refrigerant is discharged to the outside.
[0035] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments, taken in conjunction with
the accompanying drawings of which:
[0037] FIG. 1 is a front view of a conventional heat exchanger
using micro-channel tubes;
[0038] FIG. 2 is a schematic view illustrating the flow of
refrigerant in the heat exchanger of FIG. 1;
[0039] FIG. 3 is an exploded perspective view of an evaporator
using micro-channel tubes in accordance with a preferred embodiment
of the present invention;
[0040] FIG. 4 is an exploded perspective view of an upper header of
the evaporator of FIG. 3;
[0041] FIG. 5 is a perspective view of a lower header of the
evaporator of FIG. 3;
[0042] FIG. 6 is a plan view illustrating the flow of refrigerant
in the upper header of the evaporator of FIG. 3;
[0043] FIG. 7 is a top view of the evaporator of FIG. 3;
[0044] FIG. 8 is a schematic view illustrating the flow of
refrigerant in the evaporator of FIG. 3;
[0045] FIGS. 9a and 9b are plan views illustrating the flow of
refrigerant in upper headers of evaporators in accordance with
other embodiments of the present invention; and
[0046] FIGS. 10a , 10b, and 10c are front views illustrating
structures of a partition of the upper header of the evaporator
using micro-channel tubes in accordance with a preferred embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Reference will now be made in detail to the embodiments of
the present invention, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to the
like elements throughout. The embodiments are described below to
explain the present invention by referring to the figures.
[0048] As shown in FIG. 3, an evaporator using micro-channel tubes
in accordance with a preferred embodiment of the present invention
comprises two heat exchanging units 20 and 30, each of which
includes a plurality of micro-channel tubes 43 vertically erected
between a pair of headers laid horizontally. Hereinafter, the heat
exchanging unit, which is placed at the front position, is referred
to as a first heat exchanging unit 20, and the heat exchanging
unit, which is placed at the rear position, is referred to as a
second heat exchanging unit 30.
[0049] An integral upper header 50 is placed on the upper surfaces
of the first heat exchanging unit 20 and the second heat exchanging
unit 30, thus transmitting refrigerant between the first and second
heat exchanging units 20 and 30.
[0050] As shown in FIG. 4, the upper header 50 includes a base 53
provided with a plurality of longitudinal holes 58 formed
therethrough perpendicularly to the longitudinal direction of the
base 53, a cover 54 having an arc-shaped cross section placed above
the upper surface of the base 53 for forming a closed space
together with the base 53, a partition 55 for dividing the space
formed by the base 53 and the cover 54, in the longitudinal
direction of the base 53, into a first upper header unit 51 forming
a part of the first heat exchanging unit 20 and a second upper
header unit 52 forming a part of the second heat exchanging unit
30, and separators 57 for dividing each of the first upper header
unit 51 and the second upper header unit 52 into plural portions.
Openings 56 for transmitting refrigerant between the first and
second heat exchanging units 20 and 30 therethrough are formed
through the partition 55.
[0051] A plurality of micro-channel tubes (hereinafter, abbreviated
to `tubes`) 43, which are erected vertically, are connected to the
lower part of the upper header 50. Upper ends of the tubes 43 are
bonded to the upper header 50 under the condition that designated
lengths of the upper ends of the tubes 43 are inserted into the
longitudinal holes 58. The insides of the tubes 43 are divided into
plural portions so as to form fine channels. Since the
cross-sections of the tubes 43 are similar to the structure of a
harmonica, the tubes 43 are referred to as harmonica tubes.
[0052] Corrugated pins 44 are intercalated between the
micro-channel tubes 43. Preferably, louvers 44a are formed on the
corrugated pins 44 for facilitating heat transfer.
[0053] Generally, when the evaporator is installed, the surface of
the evaporator is perpendicular to the flow direction of air. As
shown in FIG. 4, water condensed on the surface of the evaporator
flows down along the surfaces of the tubes 43, which are erected
vertically, by its own weight. Water condensed on the corrugated
pins 44 flows down by the gradient of the corrugated pins 44, and
then flows down along the surfaces of the tubes 43 or flows down
again along the corrugated pins 44 at contacts between the
corrugated pins 44 and the tubes 43.
[0054] A first lower header 22 is placed below the tubes 43 of the
first heat exchanging unit 20, and a second lower header 32 is
placed below the tubes 43 of the second heat exchanging unit
30.
[0055] As shown in FIG. 5, the first lower header 22 is made of an
aluminum pipe having a circular cross-section. Since the inside of
the first lower header 22 is divided into plural portions by a
plurality of separators 23, it is possible to cut off the flow of
the refrigerant between the neighboring portions of the inside of
the first lower header 22. A plurality of longitudinal holes 24 are
formed through the upper surface of the first lower header 22 such
that the longitudinal holes 24 are perpendicular to the
longitudinal direction of the first lower header 22, and the lower
ends of the tubes 43 are bonded to the first lower header 22 under
the condition that designated lengths of the lower ends of the
tubes 43 are inserted into the longitudinal holes 43. The second
lower header 32 has the same structure as that of the first lower
header 22.
[0056] Inlet pipes 45, for inhaling the refrigerant, having passed
through an expansion valve (not shown) of the conventional
refrigerating cycle, into the evaporator, and outlet pipes 46, for
discharging the refrigerant, having vaporized by the evaporator, to
the outside of the evaporator, are connected to the lower parts of
the first lower header 22 and the second lower header 32. The
refrigerants discharged from the outlet pipes 46 are gathered in a
collecting manifold 47 connected to the lower ends of the outlet
pipes 46, and transmitted to a compressor (not shown) (with
reference to FIG. 7).
[0057] Hereinafter, with reference to FIG. 8, the flow of the
refrigerant in the evaporator using the micro-channel tubes with
reference to the above embodiment of the present invention will be
described.
[0058] An upper portion of FIG. 8 illustrates the flow of the
refrigerant in the second heat exchanging unit 30, a lower portion
of FIG. 8 illustrates the flow of the refrigerant in the first heat
exchanging unit 20, and a middle portion of FIG. 8 illustrates the
flow of the refrigerant in the upper header 50.
[0059] As described above, the inside of each of the upper header
50 and the first and second lower headers 22 and 32 is divided into
several portions by a plurality of the corresponding separators 57,
23, or 33. In the evaporator in this embodiment, the inside of each
of the upper header 50 and the first and second lower headers 22
and 32 is divided into four portions, and the four portions have
different sizes so as to form the flow of the refrigerant as shown
in FIG. 8.
[0060] In FIG. 8, a left portion 32a of the second lower header 32
and a left portion 52a of the second upper header unit 52 have the
same size, and the tubes 43, which are installed between the left
portion 32a of the second lower header 32 and the left portion 52a
of the second upper header unit 52, form one channel group G1. The
remaining portions 32b, 32c, and 32d of the second lower header 32
and the corresponding remaining portions of 52b, 52c, and 52d of
the second upper header unit 52 respectively have the same sizes,
so as to form channel groups G2, G3, and G4. In the same manner as
the second lower header 32 and the second upper header unit 52, the
first upper header unit 51 is divided into four portions 51a, 51b,
51c, and 51d, and the first lower header 22 is divided into four
portions 22a, 22b, 22c, and 22d, so as to form channel groups G5,
G6, G7, and G8 in order.
[0061] The number of the tubes 43 of any one of the channel groups
G1, G3, G6, and G8 is smaller than that of the tubes 43 of any one
of the channel groups G2, G4, G5, and G7. The above difference of
numbers of the tubes 43 among the channel groups G1, G2, G3, G4,
G5, G6, G7, and G8 reduces the decrease in the pressure of the
refrigerant in the evaporator in consideration of the expanded
volume of the refrigerant when the refrigerant is vaporized in the
evaporator.
[0062] The inlet pipe 45 is connected to the portion 32a of the
second lower header 32 connected to the channel group G1. The
refrigerant, having entered into the second lower header 32 through
the inlet pipe 45, is distributed at the portion 32a into the tubes
43 of the channel group G1. The divided parts of the refrigerant
flowing along the tubes 43 of the channel group G1 are collected at
the portion 52a of the second upper header unit 52, and the
collected refrigerant is transmitted to the portion 51a of the
first upper header unit 51 through the opening 56 of the partition
51. The refrigerant is divided again into the tubes 43 of the
channel group G5 and transmitted to the portion 22a of the first
lower header 22. The refrigerant at the portion 22a of the first
lower header 22 is discharged to the outside through the outlet
pipe 46 connected to the portion 22a.
[0063] When the refrigerant passes through the channel groups G1
and G5, the refrigerant is vaporized by exchanging heat with
peripheral air. The channel group G1, through which the refrigerant
enters to the evaporator, is an inlet-side channel group, and the
channel group G5, through which the refrigerant is discharged from
the evaporator, is an outlet-side channel group. The route of the
refrigerant from one inlet pipe 45 to the opposite outlet pipe 46
is referred to as a refrigerant circuit. In the same manner as the
channel groups G1 and G5, the channel groups G3, G6, and G8 are
inlet-side channel groups, and the channel groups G2, G4, and G7
are outlet-side channel groups, thus forming three refrigerant
circuits. Accordingly, a total of four refrigerant circuits is
formed in the evaporator, and the flow directions of the
refrigerant of the neighboring refrigerant circuits are opposite to
each other. The flow directions are designed in consideration of
the difference of the numbers of the tubes 43 among the channel
groups G1, G2, G3, G4, G5, G6, G7, and G8.
[0064] As described above, the number of the tubes 43 of any one of
the channel groups G1, G3, G6, and G8 is smaller than that of the
tubes 43 of any one of the channel groups G2, G4, G5, and G7. The
above difference of numbers of the tubes 43 among the channel
groups G1, G2, G3, G4, G5, G6, G7, and G8 denotes that the cross
sectional areas of flow channels of the outlet-side channel groups
G2, G4, G5, and G7 are greater than those of the flow channels of
the inlet-side channel groups G1, G3, G6, and G8. Since the
evaporator receives the refrigerant in a liquid state and
discharges the refrigerant in a gaseous state, the evaporator
generally has the above-described structure to reduce the decrease
of the pressure in the evaporator.
[0065] When the refrigerant is transmitted from one channel group
to the next channel group in a conventional evaporator, since the
refrigerant flows in the header and is distributed into the tubes
43, it is difficult to uniformly distribute the refrigerant. In the
evaporator in accordance with this embodiment, since the
refrigerant is transmitted through the opening 56 formed through
the partition 55 of the upper header 50, the refrigerant may be
uniformly distributed (with reference to FIG. 6).
[0066] FIGS. 9a and 9b illustrate internal structures of integral
upper headers of evaporators in accordance with other embodiments
of the present invention. In the same manner as the evaporator in
accordance with the preceding embodiment, each of the evaporators
in accordance with other embodiments comprises two heat exchanging
units. However, each of the evaporators has a refrigerant channel
structure differing from that of the evaporator of the preceding
embodiment. The evaporator of the embodiment shown in FIG. 9a has a
total of three refrigerant circuits. Each of a first upper header
unit 61 and a second upper header unit 62 of an upper header 60 is
divided into three portions by two separators 63. In the same
manner as that of the evaporator of the preceding embodiment, the
cross sectional areas of the flow channels of outlet-side channel
groups are greater than the cross sectional areas of the flow
channels of the inlet-side channel groups. The transmission of the
refrigerant between the heat exchanging units is achieved through
openings of a partition 64 of the upper header 60, and the flow
directions of the refrigerant of the neighboring refrigerant
circuits are opposite to each other, as shown by the arrows. The
evaporator of the embodiment shown in FIG. 9b has a total of two
refrigerant circuits. Each of a first upper header unit 71 and a
second upper header unit 72 of an upper header 70 is divided into
two portions by one separator 73, the cross sectional areas of the
flow channels of outlet-side channel groups are greater than those
of the flow channels of inlet-side channel groups, and the flow
directions of the refrigerant of the neighboring refrigerant
circuits are opposite to each other, as shown by the arrows.
[0067] FIGS. 10a, 10b, and 10c illustrate various modifications of
shapes, sizes, and positions of openings formed through the
partition of the upper header. A partition 81 as shown in FIG. 10a
includes circular-shaped openings 82, a partition 83 as shown in
FIG. 10b includes an opening 84 formed through the upper part
thereof, and a partition 85 as shown in FIG. 10c includes an
opening 86 formed through the whole part thereof.
[0068] The headers, the tubes, and the corrugated pins of the above
evaporator using micro-channel tubes are made of aluminum material,
and manufactured by a furnace brazing process.
[0069] As apparent from the above description, the present
invention provides an evaporator using micro-channel tubes, which
has a small size and a high efficiency, thus being capable of
miniaturizing a household air conditioner.
[0070] The evaporator of the present invention comprises a
plurality of heat exchanging units, thus having a sufficient heat
transfer area.
[0071] The evaporator of the present invention uniformly
distributes refrigerant in the installed direction thereof and the
upper header to transmit the refrigerant between the heat
exchanging units.
[0072] The evaporator of the present invention easily discharges
condensed water by the installed direction thereof.
[0073] Although a few embodiments of the present invention have
been shown and described, it would be appreciated by those skilled
in the art that changes may be made in these embodiments without
departing from the principles and spirit of the invention, the
scope of which is defined in the claims and their equivalents.
* * * * *