U.S. patent application number 11/186576 was filed with the patent office on 2006-01-26 for fluid agitating fin, method of fabricating the same and heat exchanger tube and heat exchanger or heat exchanging type gas cooling apparatus inwardly mounted with the fin.
This patent application is currently assigned to Usui Kokusai Sangyo Kaisha Limited. Invention is credited to Tadahiro Goto, Yasuaki Hashimoto.
Application Number | 20060016582 11/186576 |
Document ID | / |
Family ID | 35520167 |
Filed Date | 2006-01-26 |
United States Patent
Application |
20060016582 |
Kind Code |
A1 |
Hashimoto; Yasuaki ; et
al. |
January 26, 2006 |
Fluid agitating fin, method of fabricating the same and heat
exchanger tube and heat exchanger or heat exchanging type gas
cooling apparatus inwardly mounted with the fin
Abstract
A fluid agitating plate fin is mounted to a heat exchanger tube
to agitate a cooling fluid and to create a turbulent flow. Edges of
the plate fins are opposed to each other and the opposed butted
blade edges cross each other.
Inventors: |
Hashimoto; Yasuaki;
(Izu-shi, JP) ; Goto; Tadahiro; (Fuji-shi,
JP) |
Correspondence
Address: |
CASELLA & HESPOS
274 MADISON AVENUE
NEW YORK
NY
10016
US
|
Assignee: |
Usui Kokusai Sangyo Kaisha
Limited
Sunto-gun
JP
|
Family ID: |
35520167 |
Appl. No.: |
11/186576 |
Filed: |
July 21, 2005 |
Current U.S.
Class: |
165/109.1 |
Current CPC
Class: |
F28D 7/1684 20130101;
F28F 3/02 20130101; F02M 26/32 20160201; F28D 21/0003 20130101;
F28F 13/12 20130101; F28F 1/40 20130101 |
Class at
Publication: |
165/109.1 |
International
Class: |
F28F 13/12 20060101
F28F013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2004 |
JP |
2004-216526 |
Claims
1. A fluid agitating plate fin mounted to inside or outside of a
heat exchanger tube for making a fluid comprising a cooled medium
or a cooling medium flowing at the inside or the outside of the
heat exchanger tube bring about an agitating operation of a
turbulent flow or a vortex flow, wherein blade edges of the plate
fins are butted to be opposed to each other upward and downward and
the respective butted blade edges are mounted to the inside or the
outside of the heat exchanger tube to cross each other.
2. The fluid agitating plate fin according to claim 1, wherein a
thin plate constituting the plate material is a thin plate made of
a metal.
3. The fluid agitating plate fin according to claim 1, wherein the
fluid agitating plate fins inwardly mounted into the heat exchanger
tube to make the blade edges opposedly cross each other upward and
downward are worked respectively individually upward and
downward.
4. The fluid agitating plate fin according to claim 1, wherein the
fluid agitating plate fins inwardly mounted to the heat exchanger
tube to make the blade edges opposedly cross each other upward and
downward are respectively simultaneously worked upward and downward
at the plate material and inwardly mounted thereto by folding a
center portion of the plate material.
5. The fluid agitating plate fin according to claim 1, wherein the
fluid agitating plate fins inwardly mounted to the heat exchanger
tube by making the blade edges opposedly cross each other upward
and downward are inwardly mounted thereto by overlapping the blade
edges with a face pressure therebetween or inwardly mounted thereto
with an interval between the respective blade edges.
6. The fluid agitating plate fin according to claim 1, wherein when
portions of the plate fins for making the blade edges opposedly
cross each other upward and downward are predicted, the portions of
making the blade edges cross each other are previously formed with
bonding portions of a notch, a recess and projection or the like,
and the upward and the downward plate fins are integrally bonded by
way of the bonding portions.
7. The fluid agitating plate fin according to claim 1, wherein a
shape of the blade edge of the plate fin may be a linear shape or a
curved shape in a length direction and directions of crossing the
plate fins may stay the same or may alternately be changed.
8. The fluid agitating plate fin according to claim 1, wherein that
the heat transfer tube inwardly mounted with the plate fin is a
flat tube, a circular tube or other deformed tube.
9. The fluid agitating plate fin according to claim 1, wherein that
means for mounting the plate fin into the heat exchanger tube is
pertinently selected from soldering, welding, adhering using an
adhering agent and other bonding means.
10. A method of fabricating a fluid agitating plate fin wherein a
fluid agitating plate fin mounted to inside or outside of a heat
exchanger tube for making a fluid comprising a cooled medium or a
cooling medium flowing at the inside or the outside of the heat
exchanger tube bring about an agitating operation of a turbulent
flow or a vortex flow, wherein by forming a plurality of
predetermined notched portions at a plate material comprising a
thin plate and raising remaining notched portions of the notched
portions orthogonally to a surface of the plate material, a
plurality of plate fins are formed at the surface of the plate
material.
11. The method of fabricating a fluid agitating plate fin according
to claim 10, wherein means for forming the notched portion at the
plate material is any of a mechanical working method of pressing or
the like or a chemical working method by etching or the like or an
optical method of a laser beam or the like.
12. A heat exchanger arranged with at least one piece of a heat
exchanger tube mounted with a fluid agitating plate fin mounted to
inside or outside of the heat exchanger tube for making a fluid
comprising a cooled medium or a cooling medium flowing in the heat
exchanger tube bring about an agitating operation of a turbulent
flow or a vortex flow, wherein blade edges of the plate fins are
butted to be opposed to each other upward and downward and the
respective butted blade edges cross each other.
13. A heat exchange type gas cooling apparatus constituted by being
arranged with at least one piece or more of heat exchanger tubes
which are intersected with a flow direction of a gas flowing in a
gas pipe and in which a cooling medium flows and being mounted with
a fluid agitating plate fin contiguous to an outer periphery of the
heat exchanger tube, wherein the plate fins are mounted thereto
such that blade edges of the plate fins are butted to be opposed to
each other upward and downward and the respective butted blade
edges cross each other.
14. A heat exchanger tube constituted by being inwardly mounted
with a fluid agitating plate fin for making a fluid comprising a
cooled medium or a cooling medium flowing in a tube bring about an
agitating operation of a turbulent flow or a vortex flow, wherein
the fluid agitating plate fins are inwardly mounted thereto such
that blade edges of the plate fins are butted to be opposed to each
other upward and downward and the respective butted blade edges
cross each other.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a structure of a fin for
agitating a fluid in a heat exchanger, particularly, relates to a
fluid agitating plate fin mounted to inside or outside of a heat
exchanger tube in a heat changing type cooling apparatus and
achieving an excellent heat exchanging function by increasing
contact between a wall face of a heat exchanger tube and a fluid by
bringing about an agitating operation of a turbulent flow or a
vortex flow in the fluid comprising a cooled medium or a cooling
medium flowing inside or outside of the heat exchanger tube, a
method of fabricating the plate fin as well as a heat exchanger
tube inwardly mounted with the plate fin and a heat exchanger or a
heat exchanging type gas cooling apparatus constituted by being
arranged with at least one piece of the heat exchanger tube.
[0003] 2. Description of Related Art
[0004] In recent years, starting from an EGR cooler for
recirculating exhaust gas of an automobile, there is frequently
used a heat exchanger of various modes of fluids of liquid-liquid,
liquid-gas, gas-gas and the like of a heat exchanger for recovering
exhaust heat from exhaust gas, a fuel cooler, an oil cooler, an
intercooler and the like, and inside of a heat exchanger tube in
which the fluids flow is variously devised in order to efficiently
radiate or absorb heat held by the fluids. For example, a method of
taking out a portion of exhaust gas from an exhaust system of a
diesel engine to return again to a suction system of the engine to
be added to a mixture gas is referred to as EGR (Exhaust Gas
Recirculation), there are achieved a number of effects of
restraining generation of NOx (nitrogen oxide), reducing pump loss
or reducing loss of heat radiated to a cooling solution in
accordance with a temperature drop of combustion gas, increasing a
specific heat ratio depending on change of an amount and a
composition of a working gas, and increasing a cycle efficiency in
accordance therewith and therefore, the method is widely adopted as
an effective method for cleaning exhaust gas of the diesel engine
and improving a heat efficiency thereof.
[0005] However, when a temperature of an EGR gas rises and an
amount of the EGR gas is increased, durability of an EGR valve is
deteriorated by heat operation thereof, there is brought about a
concern of destructing the EGR valve at an early stage and
therefore, a phenomenon of deteriorating fuel cost is brought about
by reducing a charging efficiency in accordance with rise of a
suction temperature such that it is necessary to constitute a
water-cooled structure by providing a cooling system as a
preventing measure thereagainst. In order to avoid such a
situation, there is used an apparatus of cooling the EGR gas by a
cooling solution of the engine, a cold medium or cooling wind for a
car air conditioner, above all, there have been proposed a number
of EGR gas cooling apparatus of a gas-liquid heat exchanging type
for cooling the EGR gas constituting a gas by engine cooling water
and as means for promoting the heat exchanging function, various
modes of fins are inwardly mounted to a tube in which the EGR gas
flows. For example, in a heat exchanger for exchanging heat between
a gas and a liquid by arranging an outer tube for making the liquid
flow on an outer side of an inner tube for making the gas flow,
there are a double tube type heat exchanger [refer to, for example,
JP-A-11-23181 (1 to 6 pages, FIGS. 1 and 2)] in which a metal
corrugated plate is inserted into an inner tube as a fin, a double
tube type heat exchanger [refer to, for example, JP-A-2000-111277
(1 to 12 pages, FIGS. 1 to 12)] constituted by an inner tube for
making a cooled medium flow on an inner side, an outer tube
provided to surround an outer periphery of the inner tube
separately therefrom, and a heat radiating fin arranged at inside
of the inner tube and having a thermal stress alleviating function,
a double tube type heat exchanger [refer to, for example,
JP-A-2003-21478 (1 to 8 pages, FIGS. 1 to 7)] constituted by an
inner tube for making a cooled medium flow on an inner side, an
outer tube provided to surround an outer periphery of the inner
tube separately therefrom, and a cross fin arranged at inside of
the inner tube and so on.
SUMMARY OF INVENTION
[0006] In the above-described respective background arts, in cases
of the EGR gas coolers of the doubletube type disclosed in
JP-A-11-23181 (1 to 6 pages, FIGS. 1 and 2), JP-A-2000-111277 (1 to
12 pages, FIGS. 1 to 12), JP-A-2003-21478 (1 to 8 pages, FIGS. 1 to
7), although a corresponding result is expected in dividing the
flow of the gas into slender streams to increase an area of being
brought into contact with the fin by inwardly mounting the
corrugated fin or the cross fin, an inner peripheral face of an
inner face of a pipe constituting the EGR gas flow path is
frequently smooth over a total length in a length direction, heat
transfer at a vicinity of a center of the pipe becomes
insufficient, further, the gas flow flows straight along the EGR
gas pipe and therefore, there poses a problem that turbulent
formation of the gas flow becomes insufficient, a boundary layer of
a heat conducting face is not thinned sufficiently and the heat
conducting function becomes more or less deficient.
[0007] Further, in recent times, in various heat exchanger tubes
mounted not only to the EGR gas cooling apparatus but also other
cooling apparatus of a heat exchange type including the EGR gas
cooling apparatus, there have been proposed a number of fin
structures for achieving a further increase in a heat exchange
efficiency inwardly mounted to heat exchanger tubes as shown by
FIGS. 16A to 16D for making a fluid mainly comprising a cooled
medium flow bring about an agitating operation to achieve
respective initially expected results. For example, in FIG. 16A, by
providing a number of projections 30 at an inner face of a flat
heat exchanger tube 50, a cooled medium g flowing in the tube is
made to bring about a turbulent flow in accordance with an
agitating operation to increase the heat exchanging function to a
cooling medium at an outer peripheral face of the heat exchanger
tube 50. Further, in FIG. 16B, there is constructed a constitution
in which a wavy plate fin 30a is inwardly mounted to a flat heat
exchanger tube 50a, a cooled medium g flowing in the tube is
meandered, in FIG. 16C, a fin 30b in a spiral shape is inwardly
mounted to a heat exchanger tube 50b in a cylindrical shape and a
cooled medium g is swirled to bring about a vortex flow, in FIG.
16D, by integrating a baffle 30c in a flat heat exchanger tube 50c,
a cooled medium g flowing in the heat exchanger tube 50c is forced
to meander alternately to prolong a time period of staying in the
tube to thereby promote an efficient heat exchange efficiency.
Although the background arts are devised to promote an increase in
the heat exchange efficiency by forcibly bringing about a turbulent
flow or a vortex flow in the cooled medium flowing in the heat
exchanger tube by forming recesses or projections or wrinkles
directly on the inner face of the heat exchanger tube or inwardly
mounting the plate fin or the baffle in various shapes thereto,
whereas difficulties are required in working or attaching method
thereof, the sufficient function cannot be achieved to pose a
serious problem desired to improve further. It is a predetermined
object of the invention to resolve the problem to provide a fluid
agitating fin excellent in a cooling efficiency and capable of
being easily integrated to heat exchanger tubes having different
shapes despite that the fins are extremely simply worked and
despite a simple structure, a method of fabricating the fin as well
as a heat exchanger tube inwardly mounted with the fin, and a heat
exchanger or a heat exchange type gas cooling apparatus arranged
with at least one of the heat exchanger tube.
[0008] A fluid agitating plate fin according to a first aspect of
the present invention to resolve the above-described problem is
mounted to inside or outside of a heat exchanger tube for making a
fluid comprising a cooled medium or a cooling medium flowing at the
inside or the outside of the heat exchanger tube bring about an
agitating operation of a turbulent flow or a vortex flow, wherein
blade edges of the plate fins are butted to be opposed to each
other upward and downward and the respective butted blade edges are
mounted to the inside or the outside of the heat exchanger tube to
cross each other.
[0009] Further, the present invention is characterized in that the
fluid agitating plate fins inwardly mounted into the heat exchanger
tube to make the blade edges opposedly cross each other upward and
downward may be worked respectively individually upward and
downward in the fluid agitating plate fin.
[0010] Further, the present invention is characterized in that the
fluid agitating plate fins inwardly mounted to the heat exchanger
tube to make the blade edges opposedly cross each other upward and
downward may be respectively simultaneously worked upward and
downward at the plate material and inwardly mounted thereto by
folding a center portion of the plate material in the fluid
agitating plate fin.
[0011] Further, the present invention is characterized in that the
fluid agitating plate fins inwardly mounted to the heat exchanger
tube by making the blade edges opposedly cross each other upward
and downward may be inwardly mounted thereto by overlapping the
blade edges with a face pressure therebetween or inwardly mounted
thereto with an interval between the respective blade edges in the
fluid agitating plate fin.
[0012] Further, in the plate fin according to the present
invention, it is preferable that when portions of the plate fins
for making the blade edges opposedly cross each other upward and
downward are predicted, the predicted portions of making the blade
edges cross each other are previously formed with bonding portions
of a notch, a recess and projection or the like, and the upward and
the downward plate fins are integrally bonded by way of the bonding
portions.
[0013] Further, a method of fabricating a fluid agitating plate fin
according to a second aspect of the invention is characterized in a
fluid agitating plate fin mounted to inside or outside of a heat
exchanger tube for making a fluid comprising a cooled medium or a
cooling medium flowing at the inside or the outside of the heat
exchanger tube bring about an agitating operation of a turbulent
flow or a vortex flow, wherein by forming a plurality of
predetermined notched portions at a plate material comprising a
thin plate and raising remaining notched portions of the notched
portions orthogonally to a surface of the plate material, a
plurality of plate fins are formed at the surface of the plate
material.
[0014] Further, the present invention is characterized in that
means for forming the notched portion at the plate material is any
of a mechanical working method of pressing or the like or a
chemical working method by etching or the like or an optical method
of a laser beam or the like in the method of fabricating the fluid
agitating plate fin.
[0015] Further, a heat exchanger according to a third aspect of the
present invention is characterized in being arranged with at least
one piece of a heat exchanger tube mounted with a fluid agitating
plate fin mounted to inside or outside of the heat exchanger tube
for making a fluid comprising a cooled medium or a cooling medium
flowing in the heat exchanger tube bring about an agitating
operation of a turbulent flow or a vortex flow, wherein blade edges
of the plate fins are butted to be opposed to each other upward and
downward and the respective butted blade edges cross each
other.
[0016] Further, a heat exchange type gas cooling apparatus
according to a fourth aspect of the present invention is a heat
exchange type gas cooling apparatus constituted by being arranged
with at least one piece or more of heat exchanger tubes which are
intersected with a flow direction of a gas flowing in a gas pipe
and in which a cooling medium flows and being mounted with a fluid
agitating plate fin contiguous to an outer periphery of the heat
exchanger tube, wherein the plate fins are mounted thereto such
that blade edges of the plate fins are butted to be opposed to each
other upward and downward and the respective butted blade edges
cross each other.
[0017] A heat exchanger tube according to a fifth aspect of the
present invention is a heat exchanger tube constituted by being
inwardly mounted with a fluid agitating plate fin for making a
fluid comprising a cooled medium or a cooling medium flowing in a
tube bring about an agitating operation of a turbulent flow or a
vortex flow, wherein the fluid agitating plate fins are inwardly
mounted thereto such that blade edges of the plate fins are butted
to be opposed to each other upward and downward and the respective
butted blade edges cross each other.
[0018] When the fluid agitating plate fin according to the present
invention is mounted to the inside or the outside of the heat
exchanger tube in which the cooled medium or the cooling medium
flows, the blade edges of plate fins are butted to be opposed to
each other upward and downward, the respective butted blade edges
are integrated to cross each other and therefore, the fluid
comprising a gas or a liquid flowing at the inside or the outside
of the heat exchanger tube brings about the turbulent flow or the
vortex flow by complicatedly agitating flowing lines thereof, the
laminar flow is exfoliated and effective agitation is repeated.
Therefore, the fluid flowing at the inside or the outside of the
heat exchanger tube is repeatedly brought into contact with the
wall face of the heat exchanger tube, heat exchange with the
cooling medium or the cooled medium at the outer peripheral face of
the heat exchanger tube is efficiently promoted and the excellent
cooling efficiency is ensured. Further, according to the heat
exchanger of the invention arranged with at least one piece of the
heat exchanger tube according to the present invention inwardly
mounted with the plate fin, the fluid flowing in the heat exchanger
tube is repeatedly brought into contact with the wall face of the
heat exchanger tube, heat exchange to the cooling medium at the
outer peripheral face of the heat exchanger tube is efficiently
promoted and the excellent cooling efficiency is ensured. Further,
the method of fabricating the fluid agitating plate fin according
to the present invention is by extremely simple working means of
forming the plurality of plate fins at the surface of the plate
material by forming the plurality of predetermined notched portions
at the plate material comprising the thin plate and raising the
remaining notched portions of the notched portions orthogonally to
the surface of the plate material, in addition thereto, also in
integrating the plate fin to the heat exchanger tube, the plate fin
can easily be mounted inwardly not only to the flat heat exchanger
tube but also a circular tube or a deformed tube and therefore, the
plate fin can preferably be mounted as the fluid agitating plate
fin mounted to the inside or the outside of the heat exchanger tube
of not only the heat exchange type cooling apparatus but also a
heat exchanger of a cooler for a fuel, an oil cooler, an
intercooler or the like and at the same time, by the excellent heat
exchange function and by forming the core by the plate fin per se,
the plate fin contributes to solid formation of the apparatus to
enable to constitute the small-sized and light-weighted formation,
compact formation of the apparatus is realized and the apparatus
can easily be installed in a limited space.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1A is a schematic partially enlarged perspective view
for explaining a plate fin for agitating a fluid according to an
embodiment of the invention, showing a state of providing a notched
portion at a plate material of a thin plate by pressing or the
like.
[0020] FIG. 1B is a schematic partially enlarged perspective view
for explaining the plate fin for agitating a fluid according to the
embodiment of the invention and is a perspective view showing a
state of forming a plurality of the plate fins by raising the
notched portions orthogonally to a surface of the plate
material.
[0021] FIG. 2 is a front view showing a state of inserting the
plate fins provided by the embodiment into a flat heat exchanger
tube by making the plate fins opposed to each other.
[0022] FIG. 3 is a partially enlarged plane view taken along a line
A-A of FIG. 2.
[0023] FIG. 4 is a partially enlarged front view showing a state of
inserting a plate fin provided by an application example based on
the embodiment into a flat heat exchanger tube.
[0024] FIG. 5A is a partially enlarged perspective view
schematically showing a state of working a plate fin for agitating
a fluid according to other embodiment of the invention, showing a
state before being overlapped by butting blade edges thereof.
[0025] FIG. 5B is a partially enlarged perspective view
schematically showing a state of working the plate fin for
agitating a fluid according to other embodiment of the invention
and is a perspective view showing a state of overlapping the plate
fins.
[0026] FIG. 6A is a partially enlarged front view partially
exemplifying a state of butting the blade edges of the plate fins
for agitating a fluid according to an application example based on
the embodiment, showing a state in which there is a gap between the
blade edges.
[0027] FIG. 6B is a partially enlarged front view partially
exemplifying a state of butting the blade edges of the plate fins
for agitating a fluid according to an application example based on
the embodiment, showing a state in which there is not a gap between
the blade edges.
[0028] FIG. 6C is a partially enlarged front view partially
exemplifying a state of butting blade edges of plate fins for
agitating a fluid according to an application example based on the
embodiment, showing a state of fitting integrally upward and
downward by a projection provided at the blade edge.
[0029] FIG. 6D is a partially enlarged front view partially
exemplifying a state of butting the blade edges of the plate fins
for agitating a fluid according to an application example based on
the embodiment and a front view showing a state of fitting.
[0030] FIG. 7 is a partially enlarged perspective view
schematically showing still other embodiment according to the
invention.
[0031] FIG. 8 is a partially enlarged front view showing an example
of attaching a plate fin according to the invention to a heat
exchanger tube.
[0032] FIG. 9 is a partially enlarged perspective view of a plate
fin for agitating a fluid according to still other embodiment of
the invention.
[0033] FIG. 10A is a partially enlarged perspective view
schematically showing a plate fin for agitating a fluid according
to still other embodiment of the invention, forming the plate fin
in the same direction.
[0034] FIG. 10B is a partially enlarged perspective view
schematically showing a plate fin for agitating a fluid of still
other embodiment according to the invention, and a perspective view
showing a constitution formed by alternately crossing the plate
fins.
[0035] FIG. 11 is a perspective view showing a state of inwardly
mounting a plate fin for agitating a fluid of the invention to a
flat heat exchanger tube and integrating a plurality of the heat
exchanger tubes to an EGR cooler (shell and tubes type heat
exchanger).
[0036] FIG. 12A is a perspective view showing an oil cooler
inwardly mounting a plate fin for agitating a fluid of the
invention to a flat heat exchanger tube and using a single heat
exchanger tube and schematically showing a state of the single heat
exchanger tube before being integrated to a radiator bottom
jacket.
[0037] FIG. 12B is a side view showing the oil cooler inwardly
mounting the plate fin for agitating a fluid of the invention to
the flat heat exchanger tube and using the single heat exchanger
tube and schematically showing a state of forming the oil cooler by
integrating the single heat exchanger tube into the radiator bottom
jacket.
[0038] FIG. 13 is a vertical side sectional view showing a state of
mounting a plate fin for agitating a fluid to an outer peripheral
face of a flat heat exchanger tube of an EGR gas cooling apparatus
according to still other embodiment of the invention.
[0039] FIG. 14 is a horizontal front view of an EGR gas cooling
apparatus according to the embodiment.
[0040] FIG. 15 is a partially broken perspective view showing an
embodiment of integrating a plate fin according to the invention to
a plate type heat exchanger.
[0041] FIG. 16A is a schematic perspective view for explaining a
heat exchanger tube inwardly mounted with an agitating fin
structure of a prior art and is a view showing a flat heat
exchanger tube formed with a projection at a wall face of the heat
exchanger tube.
[0042] FIG. 16B is a schematic perspective view for explaining a
heat exchanger tube inwardly mounted with an agitating fin
structure of a prior art and is a view showing a state of inwardly
mounting a plate fin of a wavy type to a flat heat exchanger
tube.
[0043] FIG. 16C is a schematic perspective view for explaining a
heat exchanger tube inwardly mounted with an agitating fin
structure of a prior art and is a view showing a constitution of
inwardly mounting a strip type fin spirally at an inner peripheral
face of a circular heat exchanger tube.
[0044] FIG. 16D is a schematic perspective view for explaining a
heat exchanger tube inwardly mounted with an agitating fin
structure of a prior art and is a perspective view showing a
constitution for forming a baffle at an inner peripheral face of a
flat heat exchanger tube.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0045] Although embodiments of the invention will be explained
further in details in reference to the attached drawings as
follows, the invention is not constrained thereby. Further, a
design can freely be changed within a range of the gist of the
invention.
Embodiment 1
[0046] According to a fluid agitating plate fin 3 according to a
first embodiment of the invention, as shown by FIG. 1, thin plates
comprising austenite species stainless steel of SUS 304, SUS 316 or
the like having a thickness of about 0.1 through 0.5 mm are worked
in a rectangular shape having a predetermined dimension to provide
a plurality of plate materials, two sheets of the plate materials
are pressed to form a plurality of notched portion 2 substantially
in a channel-like shape having a predetermined dimension directions
of which alternately differ as shown by FIG. 1A. Next, remaining
notched portions of the notched portion 2 are cut to be raised to
be orthogonal to a surface of the plate member to provide a plate 1
formed with fluid agitating plate fins 3 directions of which differ
alternately at respective rows and blade edge 4 of which are
constituted by linear lines inclined to a longitudinal direction.
Thereafter, by preparing two sheets of the provided plates 1 and
butting the blade edge 4 of the plate fins 3 formed at the
respective plates 1 to be respectively opposed to each other upward
and downward to insert into a flat heat exchanger tube 5, the flat
heat exchanger tube 5 inwardly mounted with the fluid agitating
fins 3 to overlap upward and downward as shown by FIG. 2 is
finished. There are prepared a plurality of the flat heat exchanger
tubes formed by crossingly integrating the blade edges 4 of the
plate fins 3 at inside of the heat exchanger tube 5 respectively
upward and downward as shown by FIG. 3 and bringing the blade edges
into close contact with each other by extruding or pressing as
needed, the plurality of flat heat exchanger tubes are integrated
into a cooling jacket C constituting a gas flow path in an EGR gas
cooling apparatus (shell and tubes type heat exchanger) 10 as shown
by FIG. 11 to be subjected to a cooling function test, as a result,
it is confirmed that an EGR gas g at high temperature flowing in
the heat exchanger tube 5d via a bonnet D-1 is complicatedly
agitated by operation of the inwardly mounted fluid agitating plate
fins, a turbulent flow or a vortex flow is generated at a stream
line of the gas g, all of laminar flows are exfoliated, heat
exchange to the cooling jacket C at an outer periphery of the heat
exchanger tube is effectively promoted, and the EGR gas g reaching
a bonnet D-2 on an outlet side is effectively cooled to an initial
set temperature.
[0047] Although according to the fluid agitating plate fin 3 of the
embodiment, heights of the fins butted to be opposed to each other
upward and downward are formed respectively by the same height, the
invention is not restricted thereby, and it is not hampered that
the heights differ from each other as in heights h-1, h-2 of the
upward and the downward fins as shown by FIG. 4. However, in this
case, it is indispensable that a sum (h-1+h-2) of the heights of
the fins falls in a range of not exceeding an inner diameter h-3 of
a short diameter portion of the flat heat exchanger tube. Further,
although according to the embodiment, as the plate material for
forming the fin, the thin plate of the austenite species stainless
steel is adopted, it is not hampered to select the material
pertinently from other metal material so far as the material is
material having a constant mechanical strength, excellent in heat
resistance, corrosion resistance and heat conductivity and
excellent in workability. Further, although the means for forming
the notched portion 2 according to the embodiment efficiently forms
the notched portion 2 by pressing, as a method of working to form
the notched portion, the notched portion can also be machined
mechanically, further, the notched portion can be formed by etching
by chemical means in a solution corrosive for the plate material by
providing a predetermined masking or can be formed optically by
laser light ray or the like.
Embodiment 2
[0048] There is provided a fluid agitating plate fin 3a as shown by
FIG. 5B similar to embodiment 1 except that a plate material
constituted by connecting two sheets of the plate materials in
Embodiment 1 in a longitudinal direction is prepared, predetermined
notched portions are provided at plate materials on the left and on
the right of a boundary of a center folding portion 1a-3, a fluid
agitating fin 3a as shown by FIG. 5A is formed after raising
remaining notched portions of the outer notched portions,
thereafter, the plate material is folded at the center folding
portions 1a-3, and respective blade edges 4a of the fluid agitating
fins 3a formed at a plate 1 (1a-1) and a plate 2 (1a-2) are butted
to be opposed to each other, a heat exchanger tube inwardly mounted
with the plate fin 3a is finished similar to Embodiment 1 to be
subjected to a cooling test by an EGR gas cooling apparatus (shell
and tubes type heat exchanger) similar to Embodiment 1, as a
result, it is confirmed that a cooling efficiency substantially
equivalent to that of Embodiment 1 is achieved.
Embodiment 3
[0049] A fluid agitating plate fin 3b is provided similar to
Embodiment 1 except that a shape of the fluid agitating plate fin
formed to a plate material is formed by bending a shape of a blade
edge 4b in a longitudinal direction in place of the fluid agitating
plate fins 3 and 3a provided by Embodiment 1 or Embodiment 2, and
when a heat exchanger tube inwardly mounted with the fluid
agitating fin 3b is constituted by using the fin 3b and is mounted
to an EGR gas cooling apparatus to be subjected to a cooling test
similar to Embodiment 1, it is confirmed that a cooling efficiency
is further increased in comparison with that of Embodiment 1.
Embodiment 4
[0050] A fluid agitating plate fin is formed similar to Embodiment
2 except that in place of a constitution of folding to overlap the
rectangular plate material at the center folding portion 1a-3 in
the lateral width direction in Embodiment 2, a folding portion 1e-3
is provided to vertically divide a plate material 1e in a
longitudinal direction thereof as shown by FIG. 10A, and a shape of
a blade edge 4e is directed in the same direction on the left and
on the right to be subjected to a cooling test under a condition
substantially the same as that of Embodiment 2, as a result, it is
confirmed that a function equivalent to that of Embodiment 2 is
achieved. Further, a fluid agitating fin shown in FIG. 10B is an
application example of the embodiment, a fluid agitating plate fin
is formed similar to Embodiment 4 except that fins 3f on the left
side and on the right side are formed to cross alternately and is
subjected to a cooling test under the same condition, as a result,
a cooling function superior to that of the embodiment is
confirmed.
[Other Application Examples]
[0051] FIG. 6 shows constitutions exemplifying states of blade
edges of fluid agitating plate fins according to respective
embodiments of the invention, FIG. 5A shows a constitution having a
constant gap at the blade edge 4, and FIG. 5B shows a constitution
in which the blade edges 4 are butted to each other with a constant
face pressure and brought into close contact with each other
without a gap therebetween. When the same crossing portions are
predicted beforehand at blade edges illustrated in FIG. 5C and FIG.
5D, by previously providing predetermined bonding portions at the
blade edges as in a projected portion 4x and a notch 4y shown in
FIG. 5C and a projected portion 4x-1 and a notch 4y-1 shown in FIG.
5D, when the blade edges are inwardly mounted into a heat exchanger
tube or the like, the blade edges are integrated thereto integrally
upward and downward via the bonding portion. Therefore, by forming
a supporter (core) between plate fins formed by thin plates and
between a plate fin and a heat exchanger tube forming an outer
frame, rigidity (solidity) is promoted, a reinforcement member is
not needed, which contributes to small-sized and light-weighted
formation of the apparatus as a whole.
[0052] FIG. 7 shows a state of inwardly mounting a fluid agitating
plate fin 3b of the invention to a heat exchanger tube 5b
comprising a circular tube, the plate fin 3b according to the
example is inwardly mounted thereto by rounding, for example, the
plate 1 provided in Embodiment 1 to insert thereinto, by inserting
at least two sheets of the plates 1 and inwardly mounting the
plates 1 thereinto by butting the blade edges 4b of the plate fins
3b to be opposed to each other to cross each other, even in the
circular heat exchanger tube, a heat exchanging function equivalent
to that of the flat heat exchanger tube in Embodiment 1 can be
achieved.
[0053] Although means for fixedly attaching the fluid agitating
plate fins provided in the respective embodiments based on the
invention are arbitrary and not particularly restricted, for
example, as shown by FIG. 8, means for attaching the plate fins to
a flat heat exchanger tube 5c can pertinently be embodied by means
of soldering, welding and adhering by an adhering agent and the
like with respect to the bonding portions 6 and the 6-1. Further,
although in the above-described respective embodiments according to
the invention, only the EGR gas constituting a cooled medium is
exemplified as a fluid flowing in the heat exchanger tube, in other
embodiments, as shown by, for example, FIG. 13 and FIG. 14, cooling
water constituting a cooling medium can be made to flow in a heat
exchanger tube 5f and an outer side of the heat exchanger tube 5f
can also be made to constitute a flow path g of a gas constituting
a cooled medium, in this case, heat of the EGR gas brought into
contact with an outer peripheral face of the heat exchanger tube 5f
can be efficiently subjected to heat exchange by bringing about a
turbulent flow or a vortex flow in the EGR gas flowing over an
outer peripheral face of the heat exchanger tube 5f.
[0054] An oil cooler 20 is constituted by providing an oil inlet
5e-5 and an oil outlet 5e-6 as shown by FIG. 12A to, for example, a
single member 5e of a flat heat exchanger tube inwardly mounted
with the fluid agitating plate fins provided by the above-described
respective embodiments based on the invention, attaching side lids
5e-1 and 5e-2 at opening portions on both sides thereof, closing
the opening portions by calking or welding or the like and dipping
and fixing a total thereof in a radiator bottom jacket 6 as shown
by FIG. 12B by soldering. It is confirmed that oil at high
temperature constituting a cooled medium flowing from the oil inlet
5e-5 provided at the flat heat exchanger tube single member 5e is
agitated by a plurality of fluid agitating fins 3g inwardly mounted
to the flat single heat exchanger tube 5e and repeatedly brought
into contact with a wall face of the heat exchanger tube 5e by
bringing about a turbulent flow or a vortex flow, heat thereof is
effectively exchanged to cooling water C constituting a cooling
medium at an outer peripheral face of the heat exchanger tube and
when the oil flows out from the oil outlet 5e-6, the oil is cooled
substantially to an initial set temperature.
[0055] Further, although in FIG. 5 in Embodiment 2 and FIG. 10 in
Embodiment 5, directions of the notched portions are made to be
symmetric on the left and on the right of the center folding
portions 1a-3 and 1e-3, the directions may be the same and the
direction of cutting to raise the fin may be any direction.
[0056] FIG. 15 shows a state of inwardly mounting a fluid agitating
plate fin 3h to a plate type heat exchanger 40 as still other
application product based on the invention, according to the
example, the fluid agitating fin 3h according to the invention is
inwardly mounted between flat plates 40-3 partitioning a ceiling
plate 40-4 and a bottom plate 40-5 by a plural number, it is
confirmed thereby that a vortex flow or a turbulent flow is brought
about at both of a gas g constituting the cooled medium flowing
between the flat plates 40-3 and cooling water C constituting the
cooling medium, heat exchange by way of the flat plates 40-3 is
effectively promoted and an excellent cooling efficiency can be
realized, in addition thereto, it is verified that the fluid
agitating fin 3h forms a core between the ceiling plate 40-4 or the
bottom plate 40-5 and the flat plate 40-3 or between the flat
plates 40-3 to contribute to solid formation of the apparatus and
small-sized and the light-weighted formation of the heat exchanger
main body 40 is realized.
[0057] As is apparent from the above-described respective
embodiments as well as application examples thereof, the fluid
agitating plate fin according to the invention is extremely
facilitated in working the plate fin per se and the plate fin can
easily be mounted inwardly not only to the flat heat exchanger tube
but also the heat exchanger tube comprising a circular tube or
other deformed tube. Further, by mounting the heat exchanger tube
inwardly mounted with the fluid agitating plate fin provided by the
invention, the cooling apparatus of the heat exchange type starting
from the EGR gas cooling apparatus achieves an excellent cooling
efficiency despite a simple structure thereof. Therefore, since the
apparatus can be constituted by light-weighted and small-sized
formation, the apparatus can flexibly deal not only with the EGR
gas cooling apparatus for an automobile but also with a case in
which object conditions of a cooled medium and a cooling medium are
changed in viscosities or temperatures thereof as in converted into
gas-gas, gas-liquid, liquid-liquid and wide use thereof can be
expected such that the apparatus can be diverted sufficiently also
as other gas cooling apparatus, or a cooling apparatus of a liquid
of oil, fuel or the like.
* * * * *