U.S. patent application number 13/003719 was filed with the patent office on 2011-05-19 for heat transfer tube for heat exchanger, heat exchanger, refrigerating cycle apparatus, and air conditioner.
Invention is credited to Akira Ishibashi, Sangmu Lee, Takuya Matsuda.
Application Number | 20110113820 13/003719 |
Document ID | / |
Family ID | 41663734 |
Filed Date | 2011-05-19 |
United States Patent
Application |
20110113820 |
Kind Code |
A1 |
Lee; Sangmu ; et
al. |
May 19, 2011 |
HEAT TRANSFER TUBE FOR HEAT EXCHANGER, HEAT EXCHANGER,
REFRIGERATING CYCLE APPARATUS, AND AIR CONDITIONER
Abstract
To obtain a heat transfer tube for a heat exchanger or the like
which can obtain predetermined heat transfer performance without
increasing in-tube pressure loss. High ridges 22A having 10 to 20
rows with a predetermined height and low ridges 22B with a height
lower than the high ridges 22A having 2 to 6 rows between the high
ridges 22A and the high ridges 22A are provided on an inner face
helically with respect to a tube axial direction.
Inventors: |
Lee; Sangmu; (Tokyo, JP)
; Ishibashi; Akira; (Tokyo, JP) ; Matsuda;
Takuya; (Tokyo, JP) |
Family ID: |
41663734 |
Appl. No.: |
13/003719 |
Filed: |
August 5, 2009 |
PCT Filed: |
August 5, 2009 |
PCT NO: |
PCT/JP2009/063859 |
371 Date: |
January 11, 2011 |
Current U.S.
Class: |
62/498 ;
165/181 |
Current CPC
Class: |
F25B 13/00 20130101;
F28F 1/422 20130101; F28D 2021/007 20130101; F28F 1/42 20130101;
F28F 13/187 20130101; F25B 39/022 20130101; F25B 2500/01 20130101;
F28F 1/40 20130101; F25B 2309/06 20130101; F28F 1/32 20130101; F28F
2275/125 20130101; F28D 1/0477 20130101; F25B 39/00 20130101; F28D
2021/0071 20130101 |
Class at
Publication: |
62/498 ;
165/181 |
International
Class: |
F25B 23/00 20060101
F25B023/00; F28F 1/24 20060101 F28F001/24 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 8, 2008 |
JP |
2008-205073 |
Claims
1. A heat transfer tube for a heat exchanger, wherein high ridges
formed with a predetermined height in ten to twenty rows and low
ridges formed with a height lower than said high ridges in two to
six rows between said high ridge and said high ridge are provided
on an inner face of the tube, spirally with respect to a tube axial
direction.
2. The heat transfer tube for the heat exchanger of claim 1,
wherein a difference in height between said high ridges and said
low ridges is 0.04 mm or more.
3. A heat exchanger, wherein a plurality of fins for expanding an
area for heat exchange and the heat transfer tube of claim 1 are
joined by pressurizing and performing tube expansion from an inner
face side of said heat transfer tube.
4. The heat exchanger of claim 3, wherein heights in said high
ridges after tube expansion of said heat transfer tube are 0.10 to
0.26 mm.
5. The heat exchanger of claim 3, wherein a width of a distal end
portion of said high ridge after tube expansion of said heat
transfer tube is 0.035 to 0.05 mm and a width of a distal end
portion of said low ridge is 0.03 to 0.035 mm.
6. The heat exchanger of claim 3, wherein an apex angle of said
high ridge is formed to be 15 to 30 degrees and an apex angle of
said low ridge to be 5 to 15 degrees.
7. A refrigerating cycle apparatus constituting a refrigerant
circuit in which a compressor for compressing a refrigerant, a
condenser for condensing said refrigerant by heat exchange,
expanding means for decompressing the condensed refrigerant, and an
evaporator for evaporating said decompressed refrigerant by heat
exchange are connected by piping for circulating said refrigerant,
wherein the heat exchanger of claim 3 is said condenser and/or
evaporator.
8. The refrigerating cycle apparatus of claim 7, wherein as said
refrigerant, any of an HC single refrigerant, a mixed refrigerant
containing the HC, R32, R410A, R407C, tetrafluoropropene, or carbon
dioxide is used.
9. An air conditioner, wherein cooling/heating of a target space is
performed by the refrigerating cycle apparatus of claim 7.
10. A heat exchanger, wherein a plurality of fins for expanding an
area for heat exchange and the heat transfer tube of claim 2 are
joined by pressurizing and performing tube expansion from an inner
face side of said heat transfer tube.
11. The heat exchanger of claim 4, wherein a width of a distal end
portion of said high ridge after tube expansion of said heat
transfer tube is 0.035 to 0.05 mm and a width of a distal end
portion of said low ridge is 0.03 to 0.035 mm.
12. The heat exchanger of claim 4, wherein an apex angle of said
high ridge is formed to be 15 to 30 degrees and an apex angle of
said low ridge to be 5 to 15 degrees.
13. The heat exchanger of claim 5, wherein an apex angle of said
high ridge is formed to be 15 to 30 degrees and an apex angle of
said low ridge to be 5 to 15 degrees.
14. A refrigerating cycle apparatus constituting a refrigerant
circuit in which a compressor for compressing a refrigerant, a
condenser for condensing said refrigerant by heat exchange,
expanding means for decompressing the condensed refrigerant, and an
evaporator for evaporating said decompressed refrigerant by heat
exchange are connected by piping for circulating said refrigerant,
wherein the heat exchanger of claim 4 is said condenser and/or
evaporator.
15. A refrigerating cycle apparatus constituting a refrigerant
circuit in which a compressor for compressing a refrigerant, a
condenser for condensing said refrigerant by heat exchange,
expanding means for decompressing the condensed refrigerant, and an
evaporator for evaporating said decompressed refrigerant by heat
exchange are connected by piping for circulating said refrigerant,
wherein the heat exchanger of claim 5 is said condenser and/or
evaporator.
16. A refrigerating cycle apparatus constituting a refrigerant
circuit in which a compressor for compressing a refrigerant, a
condenser for condensing said refrigerant by heat exchange,
expanding means for decompressing the condensed refrigerant, and an
evaporator for evaporating said decompressed refrigerant by heat
exchange are connected by piping for circulating said refrigerant,
wherein the heat exchanger of claim 6 is said condenser and/or
evaporator.
17. An air conditioner, wherein cooling/heating of a target space
is performed by the refrigerating cycle apparatus of claim 8.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat transfer tube or the
like for a heat exchanger in which a groove is provided in an inner
face of the tube.
BACKGROUND ART
[0002] In a heat exchanger used for a refrigerating apparatus, an
air conditioner, a heat pump and the like in general, a heat
transfer tube in which a groove is formed in an inner face is
arranged with respect to a plurality of fins aligned with a
predetermined interval so as to penetrate a through hole provided
in each fin. The heat transfer tube becomes a part of a refrigerant
circuit in a refrigerating cycle apparatus, and a refrigerant
(fluid) flows through inside the tube.
[0003] The groove in the inner face of the tube is processed so
that a tube axial direction and a groove extending direction form a
predetermined angle. Here, the tube inner face has recesses and
ridges by forming the groove. A space in a recess portion is
referred to as a groove portion, while a ridge portion formed by
side walls of the adjacent grooves is referred to as a ridge
portion.
[0004] The refrigerant flowing through the above heat transfer tube
changes its phase (condensation or evaporation) through heat
exchange with air outside the heat transfer tube or the like. In
order to perform this phase change efficiently, heat transfer
performance of the heat transfer tube has been improved by increase
in a surface area inside the tube, fluid agitation effect by the
groove portion, liquid film holding effect between the groove
portions through a capillary action of the groove portion and the
like (See Patent Document 1, for example).
PRIOR ART DOCUMENT
Patent Document
[0005] [Patent Document 1] Japanese Unexamined Patent Application
Publication No. 60-142195 (page 2, FIG. 1)
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0006] The above prior-art heat transfer tube uses a metal such as
copper or copper alloy as a material in general. In the manufacture
of a heat exchanger, a mechanical tube expanding method has been
practiced in which a tube expanding ball is pushed into a tube so
as to expand the heat transfer tube from the inside so as to bring
the fin and the heat transfer tube into close contact and join
them. However, at this time, the ridge portion is crushed by the
tube expanding ball, pressure loss in the tube is increased, and
heat transfer performance in the tube is lowered, which are
problems.
[0007] The present invention was made in order to solve the above
problems and has an object to provide a heat transfer tube which
can obtain predetermined heat transfer performance without
increasing an in-tube pressure loss, a heat exchanger using the
heat transfer tube, a refrigerating cycle apparatus using the heat
exchanger and the like.
Means for Solving the Problems
[0008] A heat transfer tube for a heat exchanger according to the
present invention has high ridges formed with a predetermined
height in ten to twenty rows and low ridges with a height lower
than the high ridges in two to six rows between the high ridge and
the high ridge, spirally with respect to a tube axial direction on
an inner face of the tube.
ADVANTAGES
[0009] According to the heat transfer tube of the present
invention, since the ridge portion in the groove in the tube inner
face of the heat transfer tube is constituted by high ridges and
low ridges, when the tube is expanded by a mechanical tube
expanding method, the tube expanding ball is brought into contact
with the high ridges, their top portions are crushed by about 0.04
mm and becomes flat and their ridge heights are lowered, but since
the heights of the low ridges are lower than those of the high
ridges by 0.04 mm or more, the low ridges are not deformed and the
in-tube heat transfer performance can be improved without
increasing the pressure loss as compared with a prior-art heat
transfer tube. Also, if the heat transfer tube is expanded, an
outer face of the heat transfer tube is processed into a polygonal
shape, which can suppress spring back in the heat transfer tube to
improve adhesion between the heat transfer tube and the fin, which
is excellent in efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1(a) and (b) are diagrams illustrating a heat
exchanger 1 according to Embodiment 1 of the present invention.
[0011] FIGS. 2(a) and (b) are diagrams illustrating a shape of a
tube inner face of a heat transfer tube 20 according to Embodiment
1.
[0012] FIG. 3 is a diagram illustrating a state of tube expansion
by a mechanical tube expanding method.
[0013] FIG. 4 is a graph illustrating a relationship between the
number of rows of a high ridge 22A and a heat exchange rate.
[0014] FIG. 5 is a diagram illustrating a shape of a tube inner
face of a heat transfer tube 20 according to Embodiment 2.
[0015] FIG. 6 is a graph illustrating a relationship between a
difference between a groove portion 21 and a ridge portion 22 and a
heat exchange rate after tube expansion.
[0016] FIG. 7 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 3.
[0017] FIG. 8 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 4.
[0018] FIG. 9 is a graph illustrating a relationship between an
apex angle .alpha. of the high ridge 22A and a heat exchange
rate.
[0019] FIG. 10 is a configuration diagram of an air conditioner
according to Embodiment 5 of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
[0020] FIG. 1 is a diagram illustrating a heat exchanger 1
according to Embodiment 1 of the present invention. In FIG. 1, the
heat exchanger 1 is a fin tube heat exchanger widely used as an
evaporator and a condenser of a refrigerating apparatus, an air
conditioner and the like. FIG. 1(a) is a perspective view when the
heat exchanger 1 is cut in a vertical direction, while FIG. 1(b)
illustrates a part of a section.
[0021] The heat exchanger 1 is configured by a plurality of fins 10
for the heat exchanger and heat transfer tubes 20. The heat
transfer tubes 20 are provided with respect to the fins 10 arranged
in plural with a predetermined interval so as to penetrate through
holes provided in each fin 10. The heat transfer tube 20 becomes a
part of a refrigerant circuit in a refrigerating cycle apparatus,
and a refrigerant flows through the inside of the tube. By
transmitting heat of the refrigerant flowing through the inside of
the heat transfer tube 20 and air flowing outside through the fins
10, a heat transfer area to become a contact face with air is
expanded, and heat exchange between the refrigerant and the air can
be performed efficiently.
[0022] FIG. 2 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 1. FIG. 2
expands a portion of A in FIG. 1. FIG. 2(a) illustrates a state
before tube expansion, while FIG. 2(b) illustrates a state after
the tube expansion. The tube inner face of the heat transfer tube
20 of this embodiment has a groove portion 21 and a ridge portion
22 by forming grooves. The ridge portion 21 is constituted by two
types of ridge portions: a high ridge 22A and a low ridge 22B.
Here, a height of the low ridge 22B is lower than that of the high
ridge 22A by 0.04 mm or more. However, if a difference between the
high ridge 22A and the low ridge 22B is too large (if the low ridge
22B is too low), there is a possibility that the heat transfer
performance is lowered such as a decrease in a surface area inside
the tube or the like, and the difference is assumed to be close to
0.04 mm in this embodiment.
[0023] FIG. 3 is a diagram illustrating a state of tube expansion
by a mechanical tube expanding method. In the heat exchanger 1 in
this embodiment, first, a center part in the longitudinal direction
is bent into a hair pin shape with a predetermined bending pitch to
manufacture a plurality of hair pin tubes to become the heat
transfer tubes 20. After the hair pin tube is passed through a
through hole of the fin 10, the hair pin tube is expanded by the
mechanical tube expanding method, and the heat transfer tube 20 is
brought into close contact with the fin 10 and joined. The
mechanical tube expanding method is a method in which a rod 31
having a tube expanding ball 30 with a diameter slightly larger
than an inner diameter of the heat transfer tube 20 at a tip is
passed through the inside of the heat transfer tube 20 to expand an
outer diameter of the heat transfer tube 20 and bring it into close
contact with the fin 10.
[0024] When the tube is expanded by the mechanical tube expanding
method, through a contact with the tube expanding ball 30, a ridge
top portion of the high ridge 22A is crushed to become flat, and
the ridge height is lowered. On the other hand, since a ridge top
portion of the low ridge 22B is lower than a height of the high
ridge 22A to be crushed by 0.04 mm or more, no deformation occurs.
Since a pressure is applied to the portion of the high ridge 22A in
order to expand the tube instead of applied to all the ridge
portions in the tube to insert the tube expanding ball 30 as
before, the outer face of the heat transfer tube is processed into
a polygonal shape. Therefore, spring back of the heat transfer tube
can be suppressed. As a result, adhesion between the heat transfer
tube and the fin is improved, and efficiency in heat exchange can
be improved.
[0025] FIG. 4 is a graph illustrating a relationship between the
number of rows of the high ridges 22A and a heat exchange rate. In
FIG. 2, the high ridges 22A and the low ridges 22B are shown
alternately for explanation in this embodiment, but in actuality,
on the inner face of the heat transfer tube 20, ten to twenty rows
of high ridges 22A are spirally formed in succession in the axial
direction. Then, moreover, two to six rows of low ridges 22B are
formed between the high ridge 22A and the high ridge 22A.
[0026] As described above, in the heat exchanger 1, ten to twenty
rows of the high ridges 22A of the heat transfer tube 20 is set
because when the tube is expanded, the tube expanding ball 30 is
brought into contact with the high ridge 22A, its top portion is
crushed by about 0.04 mm and becomes flat, and the height of the
ridge is lowered, but if the number of rows of the high ridges 22A
of the heat transfer tube 20 is smaller than 10, the ridge top
portion of the low ridge 22B is also crushed to become flat, and
the in-tube heat transfer performance is lowered. Also, if the
number of rows of the high ridges is set at not less than 20, the
number of rows of the low ridges 22B is decreased, and the in-tube
heat transfer performance is lowered.
[0027] As described above, according to the heat exchanger 1 of
Embodiment 1, the ridge portion 22 of the tube inner face of the
heat transfer tube 20 is constituted by two types of ridge
portions, that is, the high ridges 22A having a predetermined
height and the low ridge ridges 22B lower than the high ridge 22A
by 0.04 mm or more, the high ridges 22A are provided in ten to
twenty rows on the tube inner face, and the low ridges 22B are
provided in two to six rows between the adjacent high ridge 22A and
the high ridge 22A, so that heat transfer performance in the heat
transfer tube 20 can be improved. Also, since the tube expanding
ball 30 expands the tube in contact only with the high ridges 22A,
the outer face of the heat transfer tube 20 is processed into a
polygonal shape, spring back of the heat transfer tube is
suppressed, and close contact between the heat transfer tube and
the fin can be achieved. Also, a heat exchange rate (ratio of heat
quantities before and after passing through the heat transfer tube)
can be increased, and energy saving can be promoted. Also, while
decrease and high efficiency of the refrigerant in the refrigerant
circuit are maintained, size reduction can be promoted.
Embodiment 2
[0028] FIG. 5 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 2. A
configuration of the heat exchanger 1 is the same as Embodiment 1.
In FIG. 5, the same reference numerals are given to portions
performing the same or corresponding roles as those of Embodiment 1
(the same applies to the embodiments below). In this embodiment, a
difference H between the groove portion 21 and the ridge portion 22
after tube expansion will be described.
[0029] FIG. 6 is a graph illustrating a relationship between a
difference between the groove portion 21 and the ridge portion 22
and the heat exchange rate after tube expansion. In the heat
transfer tube 20, the larger the difference H between the groove
portion 21 and the ridge portion 22 after the tube expansion is,
the larger the heat transfer rate becomes such that a surface area
in the tube is increased or the like. However, if the difference H
between the groove portion 21 and the ridge portion 22 becomes 0.26
mm or more, an increase amount of pressure loss becomes larger than
an increase amount of the heat transfer rate, so that the heat
exchange rate is lowered. On the other hand, if the difference H
between the groove portion 21 and the ridge portion 22 is less than
0.1 mm, the heat transfer rate is not improved. From the above, in
the heat transfer tube 20, the high ridge 22A and the low ridge 22B
are formed so that the difference H between the groove portion 21
and the ridge portion 22 after the tube expansion is 0.1 to 0.26
mm.
[0030] As described above, according to the heat exchanger 1 of
Embodiment 2, since the high ridge 22A and the low ridge 22B are
formed so that the difference H between the groove portion 21 and
the ridge portion 22 after the tube expansion is 0.1 to 0.26 mm,
the heat transfer performance in the heat transfer tube 20 can be
improved.
Embodiment 3
[0031] FIG. 7 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 3. In
Embodiment 3, in the heat exchanger 1, a distal end width W1 of a
ridge top portion of the high ridge 22A is set in a range of 0.035
to 0.05 mm and a distal end width W2 of the low ridge 22B is set in
a range of 0.03 to 0.035 mm in the heat transfer tube 20 after the
tube expansion.
[0032] Regarding the distal end width W1 of the high ridge 22A, if
it is set so that the distal end width W1 after the tube expansion
becomes 0.035 mm or less, when the tube is expanded using the tube
expanding ball 30, an upper part of the ridge top is crushed, and
pressure by insertion is weakened. Thus, the tube expansion of the
heat transfer tube 20 is insufficient, adhesion between the heat
transfer tube 20 and the fin 10 is deteriorated, and drop in the
heat transfer rate becomes remarkable. Also, if the distal end
width W1 is made to be 0.05 mm or more, a sectional area is
decreased in the groove portion 21, and a liquid film of the
refrigerant becomes thick and the heat transfer rate is greatly
lowered.
[0033] On the other hand, by setting the distal end width W2 of the
low ridge 22B at 0.03 to 0.035 mm, a skirt width of the ridge is
also narrowly formed, and by thinly forming as a whole, a heat
transfer area is increased, and an in-tube heat transfer rate is
increased.
[0034] As described above, according to the heat exchanger 1 of
Embodiment 3, since the high ridges 22A and the low ridges 22B are
formed so that the distal end width W1 of the ridge top portion of
the high ridge 22A is in a range of 0.035 to 0.05 mm and the distal
end width W2 of the low ridge 22B in a range of 0.03 to 0.035 mm,
the heat transfer performance in the heat transfer tube 20 can be
improved.
Embodiment 4
[0035] FIG. 8 is a diagram illustrating a shape of a tube inner
face of the heat transfer tube 20 according to Embodiment 4 of the
present invention. In Embodiment 4, in the heat exchanger 1, an
apex angle .alpha. of the high ridge 22A is set at 15 to 30 degrees
and the apex angle .beta. of the low ridge 22B is set at 5 to 15
degrees in the heat transfer tube 20.
[0036] FIG. 9 is a graph illustrating a relationship between the
apex angle .alpha. of the high ridge 22A and a heat exchange rate.
Basically, the smaller the apex angle in the ridge portion 22 is,
the larger the heat transfer area is increased in the heat transfer
tube 20 as a whole, and the heat transfer rate is increased.
However, if the apex angle .alpha. of the high ridge 22A is smaller
than 15 degrees, workability at manufacture of the heat exchanger 1
is greatly lowered, and the heat exchange rate is lowered in the
end. On the other hand, if the apex angle .alpha. is larger than 30
degrees, a sectional area at the groove portion 21 is decreased,
the liquid film of the refrigerant overflows the groove portion 21,
and even the ridge top portion is covered by the liquid film. Thus,
the heat transfer rate is lowered.
[0037] On the other hand, by setting the apex angle .beta. of the
low ridge 22B at 5 to 15 degrees, the skirt width of the ridge is
narrowly formed, and by thinly forming as a whole, the heat
transfer area is increased, and the in-tube heat transfer rate is
increased.
[0038] As described above, according to the heat exchanger 1 of
Embodiment 4, since the high ridges 22A and the low ridges 22B are
formed so that the apex angle .alpha. of the high ridge 22A is set
at 15 to 30 degrees and the apex angle .beta. of the low ridge 22B
is set at 5 to 15 degrees, heat transfer performance in the heat
transfer tube 20 can be improved.
Embodiment 5
[0039] FIG. 10 is a configuration diagram of an air conditioner
according to Embodiment 5 of the present invention. In this
embodiment, an air conditioner will be described as an example of a
refrigerating cycle apparatus. The air conditioner in FIG. 10 is
provided with a heat-source side unit (outdoor unit) 100 and a
load-side unit (indoor unit) 200, and they are connected by a
refrigerant piping so as to constitute a refrigerant circuit and
circulate a refrigerant. In the refrigerant piping, piping through
which a gas-phase refrigerant (gas refrigerant) flows is gas piping
300, and piping through which a liquid refrigerant (liquid
refrigerant. It might be a gas-liquid two-phase refrigerant) flows
is liquid piping 400. Here, as the refrigerant, an HC single
refrigerant or a mixed refrigerant containing the HC refrigerant,
R32, R410A, R407C, tetrafluoropropene (2,3,3,3-tetrafluoropropene,
for example), carbon dioxide and the like are supposed to be
used.
[0040] The heat-source side unit 100 in this embodiment is
constituted by each device (means) of a compressor 101, an oil
separator 102, a four-way valve 103, a heat-source side heat
exchanger 104, a heat-source side fan 105, an accumulator 106, a
heat-source side throttle device (expansion valve) 107, an
inter-refrigerant heat exchanger 108, a bypass throttle device 109,
and a heat-source side controller 111.
[0041] The compressor 101 has an electric motor 6 described in the
above embodiment and intakes the refrigerant and compresses the
refrigerant to turn it into a high-temperature and high-pressure
gas state and flow it to the refrigerant piping. Regarding
operation control of the compressor 101, by providing a master-side
inverter circuit 2, a slave-side inverter circuit 3 and the like
described in the above-mentioned embodiment in the compressor 101
and by changing an operation frequency arbitrarily, for example, a
capacity (amount of the refrigerant to be fed out per unit time) of
the compressor 101 can be finely changed.
[0042] Also, the oil separator 102 separates a lubricant discharged
from the compressor 101 while being mixed in the refrigerant. The
separated lubricant is returned to the compressor 101. The four-way
valve 103 switches a flow of the refrigerant depending on a cooling
operation and a heating operation on the basis of an instruction
from the heat-source side controller 111. Also, the heat-source
side heat exchanger 104 is constituted using the heat exchanger 1
described in the embodiments 1 to 4 to perform heat exchange
between the refrigerant and air (outside air). For example, the
heat exchanger functions as an evaporator in a heating operation
and performs heat exchange between a low-pressure refrigerant
flowing in through the heat-source side throttle device 107 and the
air to evaporate and gasify the refrigerant. Also, it functions as
a condenser in a cooling operation and performs heat exchange
between a refrigerant flowing in from the four-way valve 103 side
and compressed in the compressor 101 and the air to condense and
liquefy the refrigerant. In the heat-source side heat exchanger
104, a heat-source side fan 105 is provided in order to perform
heat exchange between the refrigerant and the air efficiently. The
heat-source side fan 105 may also have an inverter circuit (not
shown) to arbitrarily change the operation frequency of a fan motor
and to finely change a rotation speed of the fan.
[0043] The inter-refrigerant heat exchanger 108 performs heat
exchange between the refrigerant flowing through a major flow
passage in the refrigerant circuit and the refrigerant branched
from the flow passage and whose flow rate is adjusted by the bypass
throttle device 109 (expansion valve). Particularly when there is a
need to overcool the refrigerant in the cooling operation, the heat
exchanger overcools the refrigerant and supplies it to the
load-side unit 200. The inter-refrigerant heat exchanger 108 is
also constituted using the heat exchanger 1 described in the
embodiments 1 to 4.
[0044] A liquid flowing through the bypass throttle device 109 is
returned to the accumulator 106 through the bypass piping 107. The
accumulator 106 is means for accumulating an excessive liquid
refrigerant, for example. The heat-source side controller 111 is
constituted by a microcomputer or the like. The controller can
perform a wired or wireless communication with a load-side
controller 204 and controls operations of the entire air
conditioner by controlling each means relating to the air
conditioner such as operation frequency control or the like of the
compressor 101 by inverter circuit control on the basis of data
relating to detection of various detecting means (sensors) in the
air conditioner, for example.
[0045] On the other hand, the load-side unit 200 is constituted by
a load-side heat exchanger 201, a load-side throttle device
(expansion valve) 202, a load-side fan 203, and a load-side
controller 204. The load-side heat exchanger 201 is also
constituted using the heat exchanger 1 described in the embodiments
1 to 4 to perform heat exchange between the refrigerant and air in
a space to be air-conditioned. For example, the heat exchanger
functions as a condenser in the heating operation, performs heat
exchange between the refrigerant flowing in from the gas piping 300
and the air, condenses and liquefies the refrigerant (or turns it
into gas-liquid two-phase), and flows it out to the liquid piping
400 side. On the other hand, in the cooling operation, the heat
exchanger functions as an evaporator, performs heat exchange
between the refrigerant brought into a low-pressure state by the
load-side throttle device 202 and the air, makes the refrigerant
get rid of heat in the air to evaporate and gasify, and flows it
out to the gas piping 300 side. Also, in the load-side unit 200,
the load-side fan 203 for adjusting flow of air for heat exchange
is provided. An operation speed of the load-side fan 203 is
determined by a user setting, for example. The load-side throttle
device 202 is provided in order to adjust a pressure of the
refrigerant in the load-side heat exchanger 201 by changing an
opening degree.
[0046] Also, the load-side controller 204 is constituted by a
microcomputer or the like and is capable of performing a wired or
wireless communication with the heat-source side controller 111,
for example. On the basis of an instruction from the heat-source
side controller 111 and an instruction from a resident or the like,
the controller controls each device (means) of the load-side unit
200 so that the inside of a room becomes a predetermined
temperature, for example. Also, the controller transmits a signal
including data relating to detection by detecting means provided in
the load-side unit 200.
[0047] Next, an operation of the air conditioner will be described.
At first, a basic refrigerant circulation in the refrigerant
circuit during the cooling operation will be described. A
high-temperature and high-pressure gas refrigerant discharged from
the compressor 101 by a driving operation of the compressor 101 is
condensed while passing through the heat-source side heat exchanger
104 from the four-way valve 103 and flows out of the heat-source
side unit 100 as a liquid refrigerant. The refrigerant flowing into
the load-side unit 200 through the liquid piping 400 is
pressure-adjusted by the opening-degree adjustment of the load-side
throttle device 202, and a low-temperature and low-pressure liquid
refrigerant passes through the load-side heat exchanger 201,
evaporates and flows out. Then, the refrigerant passes through the
gas piping 300 and flows into the heat-source side unit 100 and is
sucked into the compressor 101 through the four-way valve 103 and
the accumulator 106, pressurized again and discharged, which makes
circulation.
[0048] Also, a basic refrigerant circulation in the refrigerant
circuit in the heating operation will be described. The
high-temperature and high-pressure refrigerant discharged from the
compressor 101 by the driving operation of the compressor 101 flows
from the four-way valve 103 into the load-side unit 200 through the
gas piping 300. In the load-side unit 200, the refrigerant is
pressure-adjusted by the opening-degree of the load-side throttle
device 202, being condensed while passing through the load-side
heat exchanger 201, and becomes an intermediate-pressure liquid or
a gas-liquid two-phase refrigerant to flow out of the load-side
unit 200. The refrigerant flowing into the heat-source side unit
100 through the liquid piping 400 is pressure-adjusted by the
opening-degree of the heat-source side throttle device 107, being
evaporated while passing through the heat-source side heat
exchanger 104, becomes a gas refrigerant and sucked into the
compressor 101 through the four-way valve 103 and the accumulator
106 to be circulated by being pressurized and discharged as
described above.
[0049] As described above, according to the air conditioner of
Embodiment 5, since the heat exchanger 1 of Embodiments 1 to 4
having a high heat exchange rate is used as an evaporator and a
condenser for the heat-source side heat exchanger 104 and the
inter-refrigerant heat exchanger 108 of the heat-source side unit
100 and the load-side heat exchanger 201 of the load-side unit 200,
a COP (Coefficient of Performance: energy consumption efficiency)
or the like can be improved, and energy saving or the like can be
promoted.
Example
[0050] An example will be described below in comparison with a
comparative example that departs from the scope of the present
invention. As shown in Table 1, heat exchangers 20 with an outer
diameter of 7 mm, a bottom thickness of the groove 21 of 0.25 mm, a
lead angle of 30 degrees, and the number of high ridge rows of 10
and 20 (Example 1 and Example 2) are produced. Also, as comparative
examples, heat exchangers with the outer diameter of 7 mm, the
bottom thickness of the grove 21 of 0.25 mm, and the number of high
ridge rows of 5 and 30 are produced (Comparative Example 1 and
Comparative Example 2).
TABLE-US-00001 TABLE 1 Row number Outer Bottom (high Heat diameter
thickness Lead ridges) exchange (mm) (mm) angle (--) rate
Comparative 7 0.25 30 degrees 5 99 Example 1 Example 1 7 0.25 30
degrees 10 101.3 Example 2 7 0.25 30 degrees 20 101 Comparative 7
0.25 30 degrees 30 99.5 Example 2
[0051] As obvious from Table 1, the heat exchangers 1 in Example 1
and Example 2 both have a higher heat exchange rate than the heat
exchangers in Comparative Example 1 and Comparative Example 2, and
the in-tube heat transfer performance is improved.
[0052] Next, as shown in Table 2, the heat exchangers 1 with an
outer diameter of 7 mm, a bottom thickness of the groove 21 of 0.25
mm, a lead angle of 30 degrees, and groove depths after tube
expansion of 0.10 mm and 0.26 mm (Example 3 and Example 4) are
produced. Also, as comparative examples, heat exchangers with the
outer diameter of 7 mm, the bottom thickness of the groove 21 of
0.25 mm, the lead angle of 30 degrees, and groove depths after tube
expansion of 0.05 mm and 0.3 mm, respectively, are produced
(Comparative Example 3 and Comparative Example 4).
TABLE-US-00002 TABLE 2 Groove depth after Outer Bottom tube Heat
diameter thickness Lead expansion exchange (mm) (mm) angle (mm)
rate Comparative 7 0.25 30 degrees 0.05 99 Example 3 Example 3 7
0.25 30 degrees 0.1 101.5 Example 4 7 0.25 30 degrees 0.26 101.2
Comparative 7 0.25 30 degrees 0.3 99.4 Example 4
[0053] As obvious from Table 2, the heat exchangers 1 of Example 3
and Example 4 both have a higher heat exchange rate than the heat
exchangers of Comparative Example 3 and Comparative Example 4, and
the in-tube heat transfer performance is improved.
[0054] Next, as shown in Table 3, the heat exchangers with an outer
diameter of 7 mm, a bottom thickness of the groove 21 of 0.25 mm, a
lead angle of 30 degrees, and ridge-portion distal end widths of
high ridges of 0.035 mm, 0.4 mm and 0.5 mm (Example 5, Example 6,
and Example 7) are produced. Also, as comparative examples, heat
exchangers with the outer diameter of 7 mm, the bottom thickness of
the groove 21 of 0.25 mm, the lead angle of 30 degrees, and
ridge-portion distal end widths of the high ridges of 0.025 mm and
0.6 mm, are produced (Comparative Example 5 and Comparative Example
6).
TABLE-US-00003 TABLE 3 Ridge- portion Outer Bottom distal end Heat
diameter thickness Lead width exchange (mm) (mm) angle (mm) rate
Comparative 7 0.25 30 degrees 0.025 99.2 Example 5 Example 5 7 0.25
30 degrees 0.035 101.2 Example 6 7 0.25 30 degrees 0.04 101.8
Example 7 7 0.25 30 degrees 0.05 101 Comparative 7 0.25 30 degrees
0.06 98 Example 6
[0055] As obvious from Table 3, all the heat exchangers 1 in
Example 5, Example 6, and Example 7 have a higher heat exchange
rate than the heat exchangers in Comparative Example 5 and
Comparative Example 6, and the in-tube heat transfer performance is
improved.
[0056] Next, as shown in Table 4, the heat exchangers 1 with an
outer diameter of 7 mm, a bottom thickness of the groove 21 of 0.25
mm, a lead angle of 30 degrees, and apex angles of 15 degrees and
30 degrees (Example 8 and Example 9) are produced from aluminum.
Also, as comparative examples, heat exchangers with the outer
diameter of 7 mm, the bottom thickness of 0.25 mm, the lead angle
of 30 degrees, and apex angles of 10 degrees and 40 degrees are
produced (Comparative Example 7 and Comparative Example 8).
TABLE-US-00004 TABLE 4 Outer Bottom Apex Heat diameter thickness
Lead angle exchange (mm) (mm) angle (degrees) rate Comparative 7
0.25 30 degrees 10 99 Example 7 Example 8 7 0.25 30 degrees 15 101
Example 9 7 0.25 30 degrees 30 101.3 Comparative 7 0.25 30 degrees
40 99.3 Example 8
[0057] As obvious from Table 4, the heat exchangers 1 of Example 8
and Example 9 both have a higher heat exchange rate than the heat
exchangers in Comparative Example 7 and Comparative Example 8, and
the in-tube heat transfer performance is improved.
INDUSTRIAL APPLICABILITY
[0058] In the above-described embodiment 5, regarding the heat
exchanger according to the present invention, an application to an
air conditioner is described. The present invention is not limited
to these apparatuses but can be applied to other refrigerating
cycle apparatus such as a refrigerating apparatus and a heat pump
having a heat exchanger constituting a refrigerant circuit and to
become an evaporator and a condenser.
REFERENCE NUMERALS
[0059] 1: heat exchanger [0060] 10: fin [0061] 20: heat transfer
tube [0062] 21: groove portion [0063] 22: ridge portion [0064] 22A:
high ridge [0065] 22B: low ridge [0066] 30: tube expansion ball
[0067] 31: rod [0068] 100: heat-source side unit [0069] 101:
compressor [0070] 102: oil separator [0071] 103: four-way valve
[0072] 104: heat-source side heat exchanger [0073] 105: heat-source
side fan [0074] 106: accumulator [0075] 107: heat-source side
throttle device [0076] 108: inter-refrigerant heat exchanger [0077]
109: bypass throttle device [0078] 110: heat-source side controller
[0079] 200: load-side unit [0080] 201: load-side heat exchanger
[0081] 202: load-side throttle device [0082] 203: load-side fan
[0083] 204: load-side controller [0084] 300: gas piping [0085] 400:
liquid piping [0086] .alpha.: apex angle [0087] H: difference
between groove portion 21 and ridge portion 22 after tube expansion
[0088] W1: distal end width of ridge top portion of high ridge 22A
[0089] W2: distal end width of ridge top portion of low ridge
22B
* * * * *