U.S. patent application number 15/120912 was filed with the patent office on 2016-12-15 for plate for use as heat exchange plate and method for manufacturing such base plate.
This patent application is currently assigned to Kaboshiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.). The applicant listed for this patent is KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). Invention is credited to Yasuyuki FUJII, Yoshio ITSUMI, Hideto OYAMA, Keitaro TAMURA.
Application Number | 20160363395 15/120912 |
Document ID | / |
Family ID | 54008860 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160363395 |
Kind Code |
A1 |
TAMURA; Keitaro ; et
al. |
December 15, 2016 |
PLATE FOR USE AS HEAT EXCHANGE PLATE AND METHOD FOR MANUFACTURING
SUCH BASE PLATE
Abstract
A plate for a heat-exchanging plate comprises a metallic flat
plate having fine irregularities formed on a surface thereof, the
metallic flat plate obtained through press-working which is
implemented as a post-process, of the flat plate. The
irregularities include a plurality of projections that are formed
at a predetermined spacing, and the plurality of projections
includes first ridges disposed at an angle +.theta. with respect to
a width direction of the plate and second ridges disposed at an
angle -.theta. with respect to the width direction of the plate,
the projections being formed into V-shapes by the first ridges and
the second ridges.
Inventors: |
TAMURA; Keitaro;
(Takasago-shi, JP) ; FUJII; Yasuyuki; (Kobe-shi,
JP) ; ITSUMI; Yoshio; (Takasago-shi, JP) ;
OYAMA; Hideto; (Takasago-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) |
Kobe-shi |
|
JP |
|
|
Assignee: |
Kaboshiki Kaisha Kobe Seiko Sho
(Kobe Steel, Ltd.)
Kobe-shi
JP
|
Family ID: |
54008860 |
Appl. No.: |
15/120912 |
Filed: |
February 19, 2015 |
PCT Filed: |
February 19, 2015 |
PCT NO: |
PCT/JP2015/054563 |
371 Date: |
August 23, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 13/04 20130101;
F28F 3/048 20130101; F28F 17/005 20130101; F28F 13/12 20130101 |
International
Class: |
F28F 13/04 20060101
F28F013/04; F28F 3/04 20060101 F28F003/04; F28F 13/12 20060101
F28F013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2014 |
JP |
2014-036890 |
Claims
1. A plate for a heat-exchanging plate, the plate comprising: a
metallic flat plate having fine irregularities formed on a surface
thereof, the metallic flat plate obtained through press-working
which is implemented as a post-process, of the flat plate, wherein
the irregularities include a plurality of projections that are
formed at a predetermined spacing; and the plurality of projections
includes first ridges disposed at an angle +.theta. with respect to
a width direction of the plate and second ridges disposed at an
angle -.theta. with respect to the width direction of the plate,
the projections being formed into V-shapes by the first ridges and
the second ridges.
2. The plate for a heat-exchanging plate according to claim 1,
wherein a groove portion is formed along a longitudinal direction
of the plate, at respective tops of the V-shapes.
3. The plate for a heat-exchanging plate according to claim 1,
wherein a height of the projections is set to be 0.02 mm or greater
and 0.1 mm or less; a width of the projections is set to be 0.08 mm
or greater and 1 mm or less; a value of .theta. is set to be
10.degree. or greater and 80.degree. or less; a width of recesses
between the projections is set to be 0.1 mm or greater and 1 mm or
less; and a pitch P.sub.1 between adjacent projections is set to be
0.2 mm or greater and 2 mm or less.
4. The plate for a heat-exchanging plate according to claim 2,
wherein a width of the groove portion is set to be 0.5 mm or
greater and 500 mm or less.
5. The plate for a heat-exchanging plate according to claim 2,
wherein the groove portion is formed in plurality, and a width
pitch P.sub.2 between adjacent groove portions is set to be 5 mm or
greater and 1000 mm or less.
6. The plate for a heat-exchanging plate according to claim 5,
wherein the irregularities of the surface of the plate are set such
that a shape parameter defined as "height (mm) of the
projections.times.width (mm) of recesses between
projections.times.[width (mm)/width pitch P.sub.2 (mm) of the
groove portions]" is 0.0025 mm.sup.2 or greater.
7. A method for producing a plate for a heat-exchanging plate, the
plate comprising a metallic flat plate having fine irregularities
formed on a surface thereof, and the metallic flat plate being
obtained through press-working which is implemented as a
post-process, of the flat plate, the method comprising: forming the
irregularities on the surface such that the irregularities include
a plurality of projections formed at a predetermined spacing; and
forming, when forming the irregularities, the plurality of
projections such that the plurality of projections includes first
ridges disposed at an angle .+-..theta. with respect to a width
direction of the plate and second ridges disposed at an angle
-.theta. with respect to the width direction of the plate, and the
projections are formed into V-shapes by the first ridges and the
second ridges.
8. The method for producing a plate for a heat-exchanging plate
according to claim 7, the method further comprising: forming a
groove portion along the longitudinal direction of the plate, at
respective tops of the V-shapes.
9. The method for producing a plate for a heat-exchanging plate
according to claim 7, wherein a height of the projections is set to
be 0.02 mm or greater and 0.1 mm or less, a width of the
projections is set to be 0.08 mm or greater and 1 mm or less; the
.theta. is set to be 10.degree. or greater and 80.degree. or less;
a width of recesses between the projections is set to be 0.1 mm or
greater and 1 mm or less; and a pitch P.sub.1 between adjacent
projections is set to be 0.2 mm or greater and 2 mm or less.
10. The method for producing a plate for a heat-exchanging plate
according to claim 8, wherein a width of the groove portion is set
to be 0.5 mm or greater and 500 mm or less.
11. The method for producing a plate for a heat-exchanging plate
according to claim 8, wherein when forming the groove portion in
plurality, a width pitch P.sub.2 between adjacent groove portions
is set to be 5 mm or greater and 1000 mm or less.
12. The method for producing a plate for a heat-exchanging plate
according to claim 11, wherein the irregularities of the surface of
the plate are designed such that a shape parameter defined as
height (mm) of the projections.times.width (mm) of recesses between
projections.times.[width (mm)/width pitch P.sub.2 (mm) of the
groove portions] is 0.0025 mm.sup.2 or greater.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plate for use as
heat-exchanging plate and to a method for producing the plate.
BACKGROUND ART
[0002] Heat-exchanging plates that are built into heat exchangers
or the like are required to exhibit high heat transfer properties.
In order to enhance heat transfer properties, it suffices to expand
the surface area of the plate through formation of micron-order
fine irregularities on the surface of the plate. For instance,
Patent Literature 1 and Patent Literature 2 disclose the following
technologies as methods for transferring micron-order fine
irregularities onto the surface of a plate.
[0003] The method for transfer onto a metal plate surface disclosed
in Patent Literature 1 involves pressing a transfer portion having
irregularities, which has been transferred to the outer peripheral
face of transfer rolls, against a metal sheet that is transported
by transport rolls. In this method, transferred portions of
irregular shape identical to those of the transfer portions of the
transfer rolls become formed on the surface of the metal sheet.
[0004] A plate of a heat-exchanging plate disclosed in Patent
Literature 2 is a plate for a heat-exchanging plate, the plate
being constituted by a titanium-made flat plate having fine
irregularities formed on the surface, and being obtained through
press working, as a post-process, of the flat plate. In this plate,
the irregularities on the surface thereof are set in such a manner
that a shape parameter defined as height (.mu.m) of
projections.times.[width (.mu.m) of recesses/pitch (.mu.m) between
adjacent projections/angle (deg) of projections] is 0.94 or
smaller.
[0005] In the technology disclosed in Patent Literature 1, the
heat-exchanging plate has enhanced heat transfer properties by
virtue of the increased surface area achieved through formation of
micron-order fine irregularities on the surface of the flat plate.
In many instances, however, plates (flat plate) having fine
irregularities formed on the surface are rarely used as they are
(i.e. with irregularities remaining thereon), as heat-exchanging
plates.
[0006] Ordinarily, a plurality of projections having a height
ranging from several mm to several cm (for instance, angular
projections referred to as "herringbone") is formed by press
working on the surface of the heat-exchanging plate. In the
technology disclosed in Patent Literature 1, therefore, the fine
irregularities formed on the surface of the plate for the
heat-exchanging plate are flattened during press working. It is
accordingly desirable to enhance the press formability of the
plate.
[0007] Therefore, Patent Literature 2 discloses a technology for
solving the issue of press formability of the above plates.
[0008] In the technology disclosed in Patent Literature 2, press
formability of the plate is enhanced by defining a shape parameter
of the irregularities that are formed on the surface of the
heat-exchanging plate. When built into a heat exchanger, the
projections formed on the plate promote turbulence and forced
convection, to thereby enhance condensation thermal transfer.
[0009] The condensation thermal transfer achieved by the
heat-exchanging plate is significantly affected by the discharge of
the generated liquid. In the uneven shape (projection shape) of the
plate formed using the technology of Patent Literature 2, however,
the effect of discharge of the generated liquid may in some
instances be weaker than expected (i.e. smaller discharge amount of
generated liquid), since the generated liquid spreads out on
account of surface tension. Heat transfer properties in a
condensation thermal transfer process are thus hard to enhance in
the plate formed using the technology of Patent Literature 2.
[0010] Further, the turbulence-promoting effect in the
heat-exchanging plate may in some instances be weaker than expected
on account of the low height and divided shape (i.e. not a shape of
contiguous projections) of the uneven shape that is formed
according to the technology of Patent Literature 2. In the uneven
shape of Patent Literature 2, moreover, the contact surface area
with a medium during condensation of a gas into liquid is small due
to the liquid film that forms in the condensation process, and thus
the effect of promoting condensation thermal transfer may be weaker
than expected.
[0011] That is, the heat-transfer performance of the
heat-exchanging plate that is built into the heat exchanger is
lowered by the liquid film that is generated when the heat
exchanger is operated. In the production of the plate for a
heat-exchanging plate, therefore, the design of the plate must
ensure that the generated liquid film is discharged with good
efficiency and that the film is thin.
CITATION LIST
Patent Literature
[0012] Patent Literature 1: Japanese Unexamined Patent Publication
No. 2006-239744
[0013] Patent Literature 2: Japanese Unexamined Patent Publication
No. 2013-76551
SUMMARY OF INVENTION
[0014] It is an object of the present invention to provide a plate
for a heat-exchanging plate of enhanced heat-transfer performance
that allows a liquid film generated during the operation of a heat
exchanger to be efficiently drained, allows forming irregularities
such that the thickness of the liquid film is reduced, and allows
enhancing heat-transfer performance without collapse of the
irregularities; and a method for producing the plate.
[0015] The plate for a heat-exchanging plate of the present
invention is a plate being constituted by a metallic flat plate
having fine irregularities formed on a surface thereof, and being
obtained through press-working, which is a post-process, of the
flat plate, wherein the irregularities include a plurality of
projections that are formed at a predetermined spacing; and the
plurality of projections includes first ridges disposed at an angle
+.theta. with respect to the width direction of the plate and
second ridges disposed at an angle -.theta. with respect to the
width direction of the plate, the projections being formed into
V-shapes by the first ridges and the second ridges.
[0016] The method for producing a plate for a heat-exchanging plate
of the present invention is a method for producing a plate being
constituted by a metallic flat plate having fine irregularities
formed on a surface thereof, and being obtained through
press-working, which is a post-process, of the flat plate, the
method including: forming the irregularities on the surface such
that the irregularities include a plurality of projections formed
at a predetermined spacing; and forming, when forming the
irregularities, the plurality of projections in such a manner that
the plurality of projections includes first ridges disposed at an
angle +.theta. with respect to the width direction of the plate and
second ridges disposed at an angle -.theta. with respect to the
width direction of the plate, and the projections are formed into
V-shapes by the first ridges and the second ridges.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a diagram illustrating schematically an uneven
shape formed on a plate for a heat-exchanging plate according to an
embodiment of the present invention.
[0018] FIG. 2 is a plan-view diagram (enlarged-view diagram of A in
FIG. 1) illustrating the shape of projections formed on the plate
according to the embodiment of the present invention.
[0019] FIG. 3 is a cross-sectional diagram of FIG. 2 along line
III-III.
[0020] FIG. 4 is a diagram for explaining the dimensions of the
uneven shape of the plate according to the embodiment of the
present invention.
[0021] FIG. 5 is a cross-sectional diagram for explaining the
dimensions of the shape of the projections formed on the plate
according to the embodiment of the present invention, being an
enlarged cross-sectional diagram of portion B in FIG. 4.
[0022] FIG. 6 is a diagram illustrating data of experiments
performed in order to derive a shape parameter.
[0023] FIG. 7 is a diagram illustrating results of a condensation
heat-transfer performance test.
[0024] FIG. 8 is a diagram illustrating a relationship between a
shape parameter of projections formed on a plate and an improvement
rate of condensation thermal transfer properties.
DESCRIPTION OF EMBODIMENTS
[0025] A plate for a heat-exchanging plate according to an
embodiment of the present invention and a method for producing the
plate will be explained next in detail with reference to
accompanying drawings.
[0026] A plate 1 for a heat-exchanging plate according to the
embodiment of the present invention is constituted by a metallic
flat plate (for instance, titanium material) having fine
irregularities formed on the surface. The plate 1 is subjected to
press working, as a post-process, to yield thereafter a
heat-exchanging plate (PHE plate). The heat-exchanging plate, which
exhibits high heat-transfer performance in a condensation thermal
transfer process, is built into a heat exchanger or the like. In
addition to the irregularities, specifically, a plurality of
projections having for instance a jagged shape generally referred
to as herringbone becomes formed on the surface of the
heat-exchanging plate through press working of the plate 1.
[0027] FIG. 1 is a diagram illustrating schematically the uneven
shape formed on the plate 1 before yielding the heat-exchanging
plate according to the embodiment of the present invention. In FIG.
1, the up-and-down direction on the paper is taken as the
longitudinal direction or length-wise direction of the plate 1, and
the left-right direction on the paper as the width direction of the
plate 1.
[0028] FIG. 2 is a plan-view diagram (enlarged-view diagram of
portion A of FIG. 1) illustrating the shape of projections 2 formed
on the plate 1. FIG. 3 is a cross-sectional diagram along line in
FIG. 2.
[0029] As illustrated in FIG. 1, irregularities are formed on the
surface 1a of the plate before yielding the heat-exchanging plate
according to the embodiment of the present invention. The
irregularities have a plurality of projections 2 that are formed at
a predetermined spacing. The spaces between the plurality of
projections 2 constitute recesses 3. The projections 2 include
first ridges 2a and second ridges 2b. The first ridges 2a are
disposed at an angle +.theta. with respect to the width direction
of the plate 1. That is, the first ridges 2a extend in a
rectilinear fashion in a direction at +.theta. with respect to the
width direction of the plate 1. The second ridges 2b are disposed
at an angle -.theta. with respect to the width direction of the
plate 1. That is, the second ridges 2b extend in a rectilinear
fashion in a direction at -.theta. with respect to the width
direction of the plate 1. The projections 2 are formed into
V-shapes by the first ridges 2a and the second ridges 2b.
[0030] In further detail, the first ridges 2a and the second ridges
2b are disposed alternately in the width direction of the plate 1.
The ridges are formed in such a manner that an extension line from
one end of each of the first ridges 2a and an extension line from
one end of the second ridges 2b intersect each other. The ridges
are formed in such a manner that an extension line from the other
end of the first ridges 2a and an extension line from the other end
of the second ridges 2b intersect each other.
[0031] Specifically, the first ridges 2a and the second ridges 2b
adjacent thereto in the projections 2 are formed to a V-shape in a
plan view, and respective tops 4 are formed at portions at which
the ends of the first ridges 2a and the ends of the second ridges
2b intersect each other. In the present embodiment, however, the
first ridges 2a and the second ridges 2b are spaced apart from each
other, since as described below a groove portion 5 is formed in the
tops 4. The groove portion 5 may be omitted. In this case, the
first ridges 2a and the second ridges 2b connect with each other,
whereby the projections 2 are formed to shapes of a repeating
plurality of V-shapes.
[0032] The plurality of first ridges 2a is disposed at equal
spacings in the longitudinal direction of the plate 1, and the
plurality of second ridges 2b is disposed likewise at equal
spacings in the longitudinal direction of the plate 1.
[0033] The term V-shape in the present embodiment denotes a shape
such as that of the cutting edges of saw teeth, in a plan view,
i.e. a shape in which ridges oriented in different directions are
disposed alternately in a continuous succession. In the plate 1,
specifically, the first ridges 2a extending in a straight line are
disposed obliquely with respect to the width direction by the angle
+.theta., while the second ridges 2b extending in a straight line
are disposed obliquely with respect to the width direction by the
angle -.theta.. That is, the leftward and downward first ridges 2a,
and the rightward and downward second ridges 2b adjacent to the
first ridges 2a are disposed alternately in the width direction of
the plate 1. The first ridges 2a are connected to other first
ridges 2a via the second ridges 2b, and the second ridges 2b are
connected to other second ridges 2b via the first ridges 2a.
[0034] The V-shaped projections 2 are formed in plurality that are
juxtaposed, in a plan view, at a predetermined spacing in the
longitudinal direction of the plate 1.
[0035] As illustrated in FIG. 3, the V-shaped projections 2 are
made up of a plurality of side walls erected in the thickness
direction of the plate 1, and top walls (top edges) that join the
respective side walls. The projections 2 in the present embodiment
have been explained as having a substantially rectangular shape in
a cross-sectional view, but the projections 2 formed on the surface
1a of the plate 1 may have for instance a substantially trapezoidal
shape or substantially angular shape, other than a substantially
rectangular shape. That is, the projections 2 may adopt any
cross-sectional shape so long as the below-described dimensions of
the projections 2 are satisfied.
[0036] Groove portions 5 are additionally formed in the plate 1
that is used in the heat-exchanging plate according to the
embodiment of the present invention. Each groove portion 5 is
formed so as to extend along the longitudinal direction of the
plate 1, at the tops 4 at which there intersect the first ridges 2a
and the second ridges 2b that make up the projections 2.
[0037] As illustrated in FIG. 2, the groove portion 5 (longitudinal
groove portion) formed in the plate is formed so as run
rectilinearly through the plurality of tops 4 which are disposed in
the length-wise direction on the plate 1. Specifically, the groove
portion 5 is formed cutting off the tops 4 of the first ridges 2a
and the second ridges 2b in the projections 2. As a result, any two
given recesses 3 positioned flanking a respective projection 2
communicate with each other via the groove portion 5. The
longitudinal groove portion 5 is set to be wider than the recesses
3 (transversal groove portion) formed between the V-shaped
projections 2 and projections 2 adjacent thereto. In FIG. 1 and
FIG. 2, the width of the longitudinal groove portions 5 has been
depicted as smaller than the width of the recesses 3, for
convenience.
[0038] In summary, the surface shape of the plate 1 for a
heat-exchanging plate according to the embodiment of the present
invention is a shape such as that of the draining grooves (tread
patterns) that are carved in the contact patch of tires used in
automobiles or the like. The transversal groove portions (recesses)
3 are formed so as to open in the width direction with respect to
the longitudinal groove portions 5 that are formed in the
longitudinal direction of the plate 1.
[0039] With the plate 1 having the uneven shape, which is formed on
the surface 1a, in a case where the plate 1 is used as a
heat-exchanging plate, flow of condensate generated in the heat
exchanger can be regulated and the condensate can be discharged
quickly in the length-wise direction of the plate 1
(heat-exchanging plate) using the longitudinal groove portions 5,
while condensation thermal transfer properties can be enhanced
through promotion of turbulence and forced convection.
[0040] The dimensions of the uneven shape on the surface of the
plate 1 according to the embodiment of the present invention
described above will be explained next in detail on the basis of
experimental results.
[0041] FIG. 4 is a diagram for explaining the dimensions of the
uneven shape formed on the plate 1. FIG. 5 is a diagram for
explaining the dimensions of the shape of the projections 2 formed
on the plate 1 (enlarged diagram of portion B in FIG. 4,
illustrating a partial cutaway cross-section of portion B). FIG. 6
is a diagram illustrating data of experiments performed in order to
derive a shape parameter. FIG. 7 is a diagram illustrating results
of a condensation heat-transfer performance test. FIG. 8 is a
diagram illustrating a relationship between a shape parameter of
the projections 2 formed on the plate 1 and an improvement rate of
condensation thermal transfer properties.
[0042] As illustrated in FIG. 4 and FIG. 5, prescribed dimensions
are set for the uneven shape of the surface of the plate 1.
[0043] Specifically, a height h of the projections 2 is set to be
0.02 mm or greater and 0.1 mm or less, and a width Wa of the
projections 2 is set to be 0.08 mm or greater and 1 mm or less. The
angle .theta. formed by the projections 2 with respect to the width
direction of the plate 1 is set to be 10.degree. or greater and
80.degree. or less. A width Wb of the recesses 3 is set to be 0.1
mm or greater and 1 mm or less.
[0044] A projection pitch P.sub.1 being the pitch between mutually
adjacent projections 2 is set to be 0.2 mm or greater and 2 mm or
less. That is, the projection pitch P.sub.1 can be regarded as a
combination of the width Wa of the projections 2 and the width Wb
of the recesses 3 (projection pitch P.sub.1=width Wa of projections
2+width Wb of recesses 3).
[0045] A width Wc of the longitudinal groove portion 5 is set to be
0.5 mm or greater and 500 mm or less. A width pitch P.sub.2 being
the pitch between mutually adjacent longitudinal groove portions 5
is set to be 5 mm or greater and 1000 mm or less.
[0046] The irregularities of the surface 1a of the plate 1 are
formed in such a manner that a shape parameter defined as "height h
(mm) of the projections 2.times.width Wb (mm) of the recesses
3.times.[width Wc (mm)/width pitch P.sub.2 (mm) of the longitudinal
groove portions 5]" is 0.0025 mm.sup.2 or greater.
[0047] An explanation follows next on the rationale behind such
dimensions of the uneven shape of the plate 1.
[0048] The inventors of the present application focused on a shape
parameter of the uneven shape "height h (mm) of the projections
2.times.width Wb (mm) of the recesses 3.times.[width Wc (mm)/width
pitch P.sub.2 (mm) of the longitudinal groove portions 5]" in order
to optimize the height h of the projections 2, the width Wa of the
projections 2, the angle .theta. of the projections 2, the width Wb
of the recesses 3, the projection pitch P.sub.1 of adjacent
projections 2, the width Wc of the longitudinal groove portions 5,
and the width pitch P.sub.2 of the adjacent longitudinal groove
portions 5, when producing the plate 1 for a heat-exchanging
plate.
[0049] To optimize the uneven shape, the inventors of the present
application produced a plurality of plates 1 having different
dimensions of the uneven shape, and examined an improvement rate on
condensation heat-transfer performance of each plate 1.
[0050] As illustrated in FIG. 6, there were produced seventeen
plates 1 of dissimilar uneven shape dimensions. In the plate 1
denoted by number 0 in FIG. 6, there is formed an uneven shape the
dimensions whereof include height h of the projections 2: 0.04 mm,
width Wa of the projections 2: 0.125 mm, width Wb of the recesses
3: 0.6 mm, projection pitch P.sub.1 of adjacent projections 2:
0.725 mm, angle .theta. of the projections 2: 45.degree., width Wc
of the longitudinal groove portions 5: 4 mm, and width pitch
P.sub.2 of adjacent longitudinal groove portions 5: 20 mm.
[0051] From the dimensions of the uneven shape, there are the
derived a parameter A (h.times.Wb) of 0.024 mm.sup.2 and a
parameter B (Wc/P.sub.2) of 0.2. In turn, a shape parameter
"(A.times.B):h.times.Wb.times.[Wc/P.sub.2]" of 0.0048 mm.sup.2 is
derived from parameters A and B.
[0052] As illustrated in FIG. 7, the plate 1 (number 0) having the
above uneven shape exhibited a heat transfer coefficient U, in a
heat exchanger, of 1044 (W/m.sup.2K). The plate 1 (number 0)
exhibited an improvement of 16% with respect to the heat transfer
coefficient U (900 (W/m.sup.2K)) of a conventional (smooth-surface)
plate (working example).
[0053] In the plate 1 denoted by number 1 in FIG. 6, there is
formed an uneven shape the dimensions whereof include height h of
the projections 2: 0.05 mm, width Wa of the projections 2: 0.1 mm,
width Wb of the recesses 3: 0.4 mm, projection pitch P.sub.1 of
adjacent projections 2: 0.5 mm, angle .theta. of the projections 2:
45.degree., width Wc of the longitudinal groove portions 5: 4 mm,
and width pitch P.sub.2 of adjacent longitudinal groove portions 5:
13.5 mm.
[0054] From the dimensions of the uneven shape, there are the
derived a parameter A (h.times.Wb) of 0.02 mm.sup.2 and a parameter
B (Wc/P.sub.2) of 0.2963. A shape parameter
"h.times.Wb.times.[Wc/P.sub.2]" of 0.0059 mm.sup.2 is derived from
parameters A and B.
[0055] The plate 1 (number 1) having the above uneven shape
exhibited an improvement of 20.6% in condensation heat-transfer
performance as compared with a conventional plate (working
example).
[0056] In the plate 1 denoted by number 2 in FIG. 6, there is
formed an uneven shape the dimensions whereof include height h of
the projections 2: 0.04 mm, width Wa of the projections 2: 0.1 mm,
width Wb of the recesses 3: 0.4 mm, projection pitch P.sub.1 of
adjacent projections 2: 0.5 mm, angle .theta. of the projections 2:
45.degree., width Wc of the longitudinal groove portions 5: 4 mm,
and width pitch P.sub.2 of adjacent longitudinal groove portions 5:
13.5 mm.
[0057] From the dimensions of the uneven shape, there are the
derived a parameter A (h.times.Wb) of 0.016 mm.sup.2 and a
parameter B (Wc/P.sub.2) of 0.2963. The shape parameter
"h.times.Wb.times.[Wc/P.sub.2]" of 0.0047 mm.sup.2 is derived from
parameters A and B.
[0058] The plate 1 (number 2) having the above uneven shape
exhibited an improvement of 10% in condensation heat-transfer
performance as compared with a conventional plate (working
example).
[0059] The plates 1 denoted by number 3 to number 13 in FIG. 6
exhibited likewise improvements of 5% or more in condensation
heat-transfer performance as compared with a conventional plate,
similarly to the plate 1 denoted by number 0 to number 2 (working
examples).
[0060] In the plate denoted by number 14 in FIG. 6, by contrast,
there is formed an uneven shape the dimensions whereof include
height h of the projections 2: 0.03 mm, width Wa of the projections
2: 0.1 mm, width Wb of the recesses 3: 0.3 mm, projection pitch
P.sub.i of adjacent projections 2: 0.4 mm, angle .theta. of the
projections 2: 45.degree., width Wc of the longitudinal groove
portions 5: 2 mm, and width pitch P.sub.2 of adjacent longitudinal
groove portions 5: 9 mm.
[0061] From the dimensions of the uneven shape, there are the
derived a parameter A (h.times.Wb) of 0.009 mm.sup.2 and a
parameter B (Wc/P.sub.2) of 0.2222. A shape parameter
"h.times.Wb.times.[Wc/P.sub.2]" of 0.002 mm.sup.2 is derived from
parameters A and B.
[0062] The plate (number 14) having the above uneven shape
exhibited merely an improvement of only 3.4% in condensation
heat-transfer performance as compared with a conventional plate
(comparative example).
[0063] As in the case of the plate denoted by number 14, the plates
denoted by number 15 and number 16 in FIG. 6 exhibited virtually no
improvement in condensation heat-transfer performance as compared
with a conventional plate (comparative examples).
[0064] As FIG. 8 reveals, the inventors of the present application
found that the shape parameter defined as "height h (mm) of the
projections 2.times.width Wb (mm) of the recesses 3.times.[width Wc
(mm)/width pitch P.sub.2 (mm) of the groove portions 5]" for
irregularities formed on the surface 1a of the plate must be 0.0025
mm.sup.2 or greater in order to improve the condensation
heat-transfer performance of the plate 1 by 5% with respect to
conventional instances.
[0065] As described above, the plate 1 for a heat-exchanging plate
according to the embodiment of the present invention allows
promoting accumulation and discharge of condensate by virtue of the
fine uneven shape, being a combination of V-shapes and longitudinal
grooves, that are formed on the surface of the plate.
[0066] By prescribing the dimensions of the projections 2, it
becomes possible to reduce the thickness of the condensate film and
increase thereby the surface area of contact with the medium during
condensation of a gas into liquid, and to form the fine uneven
shape of the surface without collapsing during press working.
[0067] That is, the plate 1 according to the embodiment of the
present invention allows producing a heat-exchanging plate the
condensation heat-transfer performance of which is far superior to
that of conventional plates.
[0068] A method for producing the plate 1 for a heat-exchanging
plate described above will be explained next.
[0069] To produce the plate 1, first, determination is made on the
material, plate thickness and external dimensions of the plate 1,
the shape of the fine irregularities that are formed on the surface
1a of the plate, as well as the dimensions of the shape, taking
into consideration the desired dimensions, plate thickness and so
forth of the heat-exchanging plate that is the final product.
[0070] When establishing the shape and shape dimensions of the fine
irregularities that are to be formed on the surface 1a of the
plate, the shape of the irregularities is prescribed to be a
V-shape, and there are prescribed the dimensions of the projections
22, the dimensions of the recesses 3, the pitch P.sub.1 of the
projections 22, the dimensions of the longitudinal groove portions
5 and the pitch P.sub.2 of the longitudinal groove portions 5 in
the V shape.
[0071] Regarding more specifically the dimensions of the
projections 2, the height h is set to lie in the range from 0.02 mm
to 0.1 mm, the width Wa is set to lie in the range from 0.08 mm to
1 mm, and the angle .theta. is set to lie in the range from
10.degree. to 80.degree.. Regarding the dimensions of the recesses
3, the width Wb is set to lie in the range from 0.1 mm to 1 mm. The
pitch P.sub.1 between projections 2 and other projections 2
adjacent thereto is set to lie in the range from 0.2 mm to 2
mm.
[0072] Regarding the dimensions of the groove portions 5, the width
Wc is set to lie in the range from 0.5 mm to 500 mm, and the width
pitch P.sub.2 between groove portions 5 and other groove portions 5
adjacent thereto is set to be 5 mm or greater and 1000 mm or
less.
[0073] The dimensions of the irregularities are set so that the
value derived from the shape parameter defined as "height h (mm) of
the projections 2.times.width Wb (mm) of the recesses
3.times.[width Wc (mm)/width pitch P.sub.2 (mm) of the groove
portions 5]" is 0.0025 mm.sup.2 or greater.
[0074] On the basis of the above items thus defined, a metallic
flat plate (for instance, titanium material) that constitutes the
plate 1 is prepared, and the plate 1 is formed to a predetermined
size. A lubricating layer formed on the surface 1a of the plate is
removed by a laser processing method, and the portion having had
the layer removed therefrom is pickled, to form thereby fine
irregularities and produce the plate 1 for a heat-exchanging
plate.
[0075] By resorting to the production method of the present
embodiment to form the irregularities, it becomes possible to form
a fine uneven shape (microscopic irregularities) being a
combination of V-shapes and longitudinal grooves on the surface,
and to produce a plate 1 of very good heat transfer properties
(very high heat transfer rate).
[0076] The embodiment disclosed herein is, in all features thereof,
exemplary in nature, and is not meant to be limiting in any
way.
[0077] The production method of the present embodiment is
appropriate for producing a plate 1 for a heat-exchanging plate in
which a flat plate made of titanium is utilized, but can also be
resorted to in order to produce a plate 1 for a heat-exchanging
plate in which a plate made of an aluminum alloy or a high-tensile
plate is utilized. That is, a plate of any material may be used in
the method for producing a plate 1 for a heat-exchanging plate of
the present embodiment, so long as the plate is made of metal.
[0078] In particular, features not explicitly described in the
embodiments disclosed herein, for instance operational conditions,
working conditions, various parameters, as well as dimensions,
weight, volume and so forth of constructions are features that do
not depart from the scope of ordinary implementation by a person
skilled in the art, and take on values that can be easily conceived
of by a normal person skilled in the art.
[0079] An outline of the above embodiment follows next.
[0080] The plate for a heat-exchanging plate of the above
embodiment is a plate being constituted by a metallic flat plate
having fine irregularities formed on a surface thereof, and being
obtained through press-working, which is a post-process, of the
flat plate, wherein the irregularities include a plurality of
projections that are formed at a predetermined spacing; and the
plurality of projections includes first ridges disposed at an angle
+.theta. with respect to the width direction of the plate and
second ridges disposed at an angle -.theta. with respect to the
width direction of the plate, the projections being formed into
V-shapes by the first ridges and the second ridges.
[0081] Preferably, a groove portion may be formed along the
longitudinal direction of the plate, at respective tops of the
V-shapes.
[0082] Preferably, the height of the projections may be set to be
0.02 mm or greater and 0.1 mm or less; the width of the projections
may be set to be 0.08 mm or greater and 1 mm or less; the value of
.theta. may be set to be 10.degree. or greater and 80.degree. or
less; the width of recesses between the projections may be set to
be 0.1 mm or greater and 1 mm or less; and the pitch P.sub.1
between adjacent projections may be set to be 0.2 mm or greater and
2 mm or less.
[0083] Preferably, the width of the groove portion may be set to be
0.5 mm or greater and 500 mm or less.
[0084] Preferably, the groove portion may be formed in plurality,
and the width pitch P.sub.2 between adjacent groove portions may be
set to be 5 mm or greater and 1000 mm or less.
[0085] Preferably, the irregularities of the surface of the plate
may be set such that a shape parameter defined as "height (mm) of
the projections.times.width (mm) of recesses between
projections.times.[width (mm)/width pitch P.sub.2 (mm) of the
groove portions]" is 0.0025 mm.sup.2 or greater.
[0086] The method for producing a plate for a heat-exchanging plate
of the present invention is a method for producing a plate being
constituted by a metallic flat plate having fine irregularities
formed on a surface thereof, and being obtained through
press-working, which is a post-process, of the flat plate, the
method including: forming the irregularities on the surface such
that the irregularities include a plurality of projections formed
at a predetermined spacing; and forming, when forming the
irregularities, the plurality of projections in such a manner that
the plurality of projections includes first ridges disposed at an
angle +.theta. with respect to the width direction of the plate and
second ridges disposed at an angle -.theta. with respect to the
width direction of the plate, and the projections are formed into
V-shapes by the first ridges and the second ridges.
[0087] Preferably, groove portions may be formed along the
longitudinal direction of the plate, at respective tops of the
V-shapes.
[0088] Preferably, the height of the projections may be set to be
0.02 mm or greater and 0.1 mm or less; the width of the projections
may be set to be 0.08 mm or greater and 1 mm or less; .theta. may
be set to be 10.degree. or greater and 80.degree. or less; the
width of recesses between the projections may be set to be 0.1 mm
or greater and 1 mm or less; and the pitch P.sub.1 between adjacent
projections may be set to be 0.2 mm or greater and 2 mm or
less.
[0089] Preferably, the width of the groove portion may be set to be
0.5 mm or greater and 500 mm or less.
[0090] When forming the groove portion in plurality, preferably, a
width pitch P.sub.2 between adjacent groove portions may be set to
be 5 mm or greater and 1000 mm or less.
[0091] Preferably, the irregularities of the surface of the plate
may be designed such that a shape parameter defined as height (mm)
of the projections.times.width (mm) of recesses between
projections.times.[width (mm)/width pitch P.sub.2 (mm) of the
groove portions] is 0.0025 mm.sup.2 or greater.
[0092] The plate for a heat-exchanging plate and the method for
producing the plate in the above embodiment allow a liquid film
generated during the operation of a heat exchanger to be
efficiently discharged, allow forming irregularities such that the
thickness of the liquid film is reduced, and allow enhancing
heat-transfer performance without collapse of the
irregularities.
* * * * *