U.S. patent application number 11/853132 was filed with the patent office on 2008-07-03 for ventilating apparatus, heat exchange apparatus, heat exchange element, and rib therefor.
Invention is credited to Han Lim Choi, Sung Won Han, Woo Ram LEE.
Application Number | 20080156469 11/853132 |
Document ID | / |
Family ID | 39149183 |
Filed Date | 2008-07-03 |
United States Patent
Application |
20080156469 |
Kind Code |
A1 |
LEE; Woo Ram ; et
al. |
July 3, 2008 |
VENTILATING APPARATUS, HEAT EXCHANGE APPARATUS, HEAT EXCHANGE
ELEMENT, AND RIB THEREFOR
Abstract
A ventilating apparatus, a heat exchange apparatus, a heat
exchange element, and a rib therefor are provided. The heat
exchange element includes a plurality of heat exchange sheets which
are multi-stacked, and a plurality of ribs arranged between the
heat exchange sheets to form ducts with the heat exchange sheets.
Each of the plurality of ribs includes an irregular structural
surface including an uneven portion. The uneven portion may include
a recess portion, a protrusion portion, or a combination of a
recess portion and a protrusion portion, which generates a
turbulent flow in a heat exchange gas flowing through the duct.
Such heat exchange element having such a rib may minimize duct
resistance by suppressing a laminar flow and growth of a boundary
layer in airflow of outdoor and indoor air passing through a heat
exchanger, and may further increase heat exchange efficiency
because the heat exchange gas may be introduced/exhausted smoothly
at a low flow velocity.
Inventors: |
LEE; Woo Ram; (Seoul,
KR) ; Han; Sung Won; (Seoul, KR) ; Choi; Han
Lim; (Bucheon-si, KR) |
Correspondence
Address: |
KED & ASSOCIATES, LLP
P.O. Box 221200
Chantilly
VA
20153-1200
US
|
Family ID: |
39149183 |
Appl. No.: |
11/853132 |
Filed: |
September 11, 2007 |
Current U.S.
Class: |
165/166 |
Current CPC
Class: |
F28F 3/048 20130101;
F28F 13/185 20130101; F28D 9/0062 20130101; F28F 2250/108 20130101;
F28F 13/12 20130101 |
Class at
Publication: |
165/166 |
International
Class: |
F28F 3/12 20060101
F28F003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2006 |
KR |
10-2006-0135574 |
Claims
1. A rib for a heat exchange element configured to guide a flow of
heat exchange gas, comprising: at least one first surface that
contacts a heat exchange sheet; and at least one second surface
that contacts the heat exchange gas, wherein the at least one
second surface includes an irregular structural surface having an
uneven portion.
2. The rib according to claim 1, wherein the uneven portion
includes a recess portion, a protrusion portion, or a combination
of a recess portion and a protrusion portion provided on the at
least one second surface.
3. The rib according to claim 1, wherein a mean height of the at
least one second surface corresponds to a value that minimizes
pressure drop of the heat exchange gas.
4. The rib according to claim 1, wherein a mean height of the at
least one second surface corresponds to a value that minimizes
velocity drop of the heat exchange gas.
5. The rib according to claim 1, wherein a mean height of the at
least one second surface is constant in a straight section of the
rib.
6. A heat exchange element comprising the rib of claim 1.
7. A heat exchange apparatus comprising the heat exchange element
of claim 6.
8. A ventilation apparatus comprising the heat exchange apparatus
of claim 7.
9. A heat exchange element, comprising: a plurality of heat
exchange sheets which are multi-stacked; and a plurality of ribs
arranged between the heat exchange sheets to form ducts with the
heat exchange sheets, wherein each of the plurality of ribs
comprises an irregular structural surface including an uneven
portion.
10. The heat exchange element according to claim 9, wherein the
uneven portion includes a recess portion, a protrusion portion, or
a combination of a recess portion and a protrusion portion, which
generates a turbulent flow in a heat exchange gas flowing through
the duct.
11. The heat exchange element according to claim 9, wherein a mean
height of the irregular structural surface corresponds to a value
that minimizes internal pressure drop of the heat exchange gas.
12. The heat exchange element according to claim 9, wherein a mean
height of the irregular structural surface corresponds to a value
that minimizes internal flow velocity drop of the heat exchange
gas.
13. The heat exchange element according to claim 9, wherein a mean
height of the irregular structural surface is constant in a
straight section of the rib.
14. A heat exchange apparatus comprising the heat exchange element
of claim 9.
15. A ventilation apparatus comprising the heat exchange apparatus
of claim 14.
Description
[0001] This application claims priority to Korean Application No.
10-2006-0135574, filed in Korea on Dec. 27, 2006, which is hereby
incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field
[0003] A ventilating apparatus, a heat exchange apparatus, a heat
exchange element, and a rib therefor are disclosed herein.
[0004] 2. Background
[0005] Ventilating apparatus and heat exchange apparatus are known.
However, they suffer from various disadvantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments will be described in detail with reference to
the following drawings in which like reference numerals refer to
like elements, and wherein:
[0007] FIG. 1 is a perspective view of internal structure of a
ventilating apparatus according to an embodiment;
[0008] FIG. 2 is a sectional view illustrating introduction/exhaust
of outdoor air in the ventilating apparatus of FIG. 1;
[0009] FIG. 3 is a sectional view illustrating introduction/exhaust
of indoor air in the ventilating apparatus of FIG. 1;
[0010] FIG. 4 is an exploded perspective view of heat exchange
elements having ribs without irregular structural surfaces;
[0011] FIGS. 5 and 6 are sectional views of a velocity distribution
of heat exchange gas in the heat exchange element of FIG. 4;
[0012] FIG. 7 is a sectional view of heat exchange elements having
ribs with irregular structural surfaces according to an
embodiment;
[0013] FIG. 8 is a sectional view of a rib with an irregular
surface structure in the form of an uneven portion having irregular
shapes and random arrangement of an uneven portion according to an
embodiment; and
[0014] FIG. 9 is a perspective view of a heat exchange element
having ribs with irregular structural surfaces according to an
embodiment.
DETAILED DESCRIPTION
[0015] In general, a ventilating apparatus, which is an air
conditioning apparatus used for ventilating an enclosed space, for
example, a room, functions to heat exchange incoming outdoor air
with outgoing indoor air before the outdoor air is introduced
indoors. In other words, the ventilating apparatus is a kind of air
conditioning apparatus that ventilates a room, such that an indoor
temperature does not decrease or increase abruptly even though the
outdoor air is introduced during ventilation.
[0016] A ventilating apparatus that performs both a heat-exchange
function and a moisture-exchange function between incoming air and
outgoing air is configured with a plurality of ducts that are
arranged to cross one another or arranged in parallel. The outdoor
air and the indoor air, which will be heat exchanged with each
other, flow in different directions through each of adjacent
ducts.
[0017] An important performance factor in a related art ventilating
apparatus is to maintain the temperature and humidity of air at an
inlet portion to be almost equal to the temperature and humidity of
air at an outlet portion by heat exchanging and moisture exchanging
the indoor air with the outdoor air. To accomplish this, components
of the heat exchanger constituting each of the ducts must have
maximum heat transfer efficiency and moisture permeability, and
each of the ducts must be arranged small and compact as possible to
contact air over the broadest surface area.
[0018] In addition to the above, it is necessary to minimize noise
and power consumption in introducing fresh outdoor air and
exhausting indoor air for ventilation. To minimize noise and power
consumption, the conduit resistance of an internal heat exchange
duct must be low. However, it is undesirable to reduce the size of
a duct without limit and increase a length and density of a duct
infinitely in order to realize the above conditions.
[0019] Therefore, to satisfy the incompatible conditions disclosed
above at the same time, a variety of shapes and materials of ducts
have been developed. One heat exchange duct includes heat exchange
sheets and ribs that maintain the multi-stacked arrangement of the
heat exchange sheets. Main heat exchange is performed through heat
transfer and moisture permeation between the heat exchange sheets.
The heat exchange sheet may be made of thin paper, and thus, the
heat exchange sheet may sag if it absorbs moisture.
[0020] Further, the ribs may be attached to the heat exchange sheet
in molten resin form and then cured to thereby constitute ducts
with the heat exchange sheet. The ribs may be provided on both
sides of the heat exchange sheet, and thus different gases (these
gases may be outdoor air and indoor air typically, but there is no
particular limitation) flow in such a way that they cross each
other or flow in an opposite direction (for example, in parallel
and opposite directions to each other). In such a case, there may
occur a case where pressure or flow velocity is not uniform in each
duct or even in the same duct depending on specific positions.
[0021] FIG. 1 is a perspective view of internal structure of a
ventilating apparatus according to an embodiment FIG. 2 is a
sectional view illustrating introduction/exhaust of outdoor air in
the ventilating apparatus of FIG. 1. FIG. 3 is a sectional view
illustrating introduction/exhaust of indoor air in the ventilating
apparatus of FIG. 1. Referring to FIG. 1, the ventilating apparatus
10 may include a case 11 forming an external shape, a heat
exchanger 20 received in the case 11, an intake fan 16, shown in
FIG. 2, configured to introduce outdoor air, and an exhaust fan 17,
as shown in FIG. 3 configured to introduce indoor air. The heat
exchanger 20 may heat exchange incoming outdoor air and outgoing
indoor air with each other.
[0022] More specifically, an intake air inlet 12 that introduces
outdoor air and an exhaust air outlet 15 that exhausts indoor air
to the outside may be provided at one side of the case 11. At the
other side of the case 11, an intake air outlet 13 that discharges
the introduced outdoor air to the indoor space, and an exhaust air
inlet 14 that introduces the indoor air may be provided.
[0023] An intake passage may be provided between the intake air
inlet 12 and the intake air outlet 13 in the form of a duct. The
heat exchanger 20 may be positioned in a middle portion of the
intake passage or duct. An exhaust passage may also provided
between the exhaust air inlet 14 and the exhaust air outlet 15 in
the form of a duct. Likewise, the heat exchanger 20 may be
positioned in a middle portion of the exhaust passage or duct. The
outdoor air introduced through the intake air inlet 12 and the
indoor air introduced through the exhaust air inlet 14 may be heat
exchanged with each other without being mixed, while passing
through the heat exchanger 20.
[0024] As set for the above, FIG. 2 is a sectional view
illustrating the introduction/exhaust of outdoor air in the
ventilating apparatus of FIG. 1, while FIG. 3 is a sectional view
illustrating the introduction/exhaust of indoor air in the
ventilating apparatus of FIG. 1. Referring to FIG. 2, the intake
fan 16 may be mounted inside the duct at a side of the intake air
outlet 13 to introduce the outdoor air. The outdoor air may be
introduced through the intake air inlet 12 by operation of the
intake fan 16, and then may be heat exchanged with the indoor air
while passing through the heat exchanger 20.
[0025] Referring to FIG. 3, the exhaust fan 17 may be mounted
inside the duct at a side of the exhaust air outlet 15 to introduce
the indoor air. The indoor air is introduced through the exhaust
inlet 14 by the operation of the exhaust fan 17, and the indoor air
is then heat exchanged with the outdoor air while passing through
the heat exchanger 20.
[0026] The heat exchanger 20 may include a plurality of stacked
heat exchange plates. The heat exchange plates may be configured
such that guide ribs are disposed between heat exchange sheets. The
combination structure of the heat exchange sheet and the guide rib
may constitute a duct that guides the introduced indoor air or
outdoor air. The duct through which the indoor air flows and the
duct through which the outdoor air flows may be cross-arranged at
left and right sides of the heat exchange sheet, respectively.
Therefore, the outdoor air and the indoor air may be only heat
exchanged with each other without being mixed, while they pass
through the heat exchanger 20.
[0027] FIG. 4 is an exploded perspective view of a heat exchange
element. Referring to FIG. 4, the heat exchange element may be in
the shape of a hexagonal plane as a unit element. In more detail,
an intake heat exchange element 21 and an exhaust heat exchange
element 22, which both may have hexagonal shapes, may be
alternately stacked. The intake passage and the exhaust passage are
provided between the intake heat exchange element 21 and the
exhaust heat exchange element 22.
[0028] More specifically, the intake heat exchange element 21 may
include a heat exchange sheet 211, which may be made of a thin
paper material, introduction guide ribs 212, which may be disposed
on one side of the heat exchange sheet 211 such that they are
spaced apart by predetermined distances, and a frame 213 provided
at an edge portion of the heat exchange sheet 211 to maintain the
shape of the intake heat exchange element 21. The introduction
guide ribs 212 may be divided into three sections, for example, an
outdoor air intake section, an intermediate section and an outdoor
air exhaust section. The outdoor air intake section and the outdoor
air exhaust section may be disposed on both edges of the
intermediate section, respectively. The introduction guide rib 212
of the outdoor air intake section and the outdoor air exhaust
section may be bent such that it is inclined at a predetermined
angle with respect to the introduction guide rib 212 of the
intermediate section.
[0029] That is, the introduction guide rib 212 may be configured
with an intake portion 212a, a straight portion 212b, and an
exhaust portion 212c. The straight portion 212b may extend from the
intake portion 212a such that it is inclined at a predetermined
angle with respect to the intake portion 212a. The exhaust portion
212c may further extend from an end of the straight portion 212b
such that it is inclined at a predetermined angle with respect to
the straight portion 212b.
[0030] Similar to the intake heat exchange element 21, the exhaust
heat exchange element 22 may include a heat exchange sheet 221,
exhaust guide ribs 222, which may be disposed on attached to one
side of the heat exchange sheet 21 such that they are spaced apart
by predetermined distance, and a frame 223. The exhaust guide rib
222 may also be configured with an intake portion 222a, a straight
portion 222b and an exhaust portion 222c. However, it is noted that
the intake portion 222a and the exhaust portion 222c of the exhaust
guide rib 222 may be respectively inclined in directions symmetric
to the intake portion 212a and the exhaust portion 212c of the
introduction guide rib 212.
[0031] As illustrated in FIGS. 2 and 3, the intake portion 212a of
the introduction guide rib 212 may be inclined such that it crosses
the intake portion 222a of the exhaust guide rib 222. Of course,
the exhaust portions 212c and 222c may be inclined such that they
cross each other in the same manner. The intake portion of the
intake heat exchange element 21 and the intake portion of the
exhaust heat exchange element 22 may cross each other, or the
exhaust portion of the intake heat exchange element 21 and the
exhaust portion of the exhaust heat exchange element 22 may cross
each other.
[0032] The intermediate sections of the introduction and exhaust
guide ribs 212 and 222, in which heat exchange operation may be
effectively performed, may be arranged in parallel, but incoming
air and outgoing air flow in opposite directions to each other,
respectively, which makes it possible to increase heat exchange
efficiency as much as possible.
[0033] That is, the outdoor air and the indoor air may be heat
exchanged with each other substantially more or the most in the
section where they pass through the straight portions 212b and 222b
than in any other section. The heat is sufficiently exchanged
between the incoming air and the outgoing air as a length of the
straight portion increases. However, this inevitably leads to a
decrease of flow velocity of air.
[0034] FIGS. 5 and 6 are sectional views of a velocity distribution
of heat exchange gas in the heat exchange element of FIG. 4.
Referring to FIGS. 5 and 6, the introduction guide rib 212 and an
exhaust guide rib 222 may be provided such that they are stacked.
Outdoor air is introduced along the introduction guide rib 212, and
indoor air is introduced along an exhaust guide rib 222. Assuming
that ribs have the shape of a quadratic prism, four surfaces of the
quadratic prism may be divided into a pair of first surfaces
contacting the heat exchange sheet, and a pair of second surfaces
contacting the heat exchange gas directly. When the heat exchange
gas flow is a laminat flow, a velocity distribution 240 of the heat
exchange gas in each duct formed by the ribs may be represented as
a parabolic profile because gas velocity is the highest at a center
of the duct, progressively decreases far from the center, and
becomes approximately 0 on the surface of the ribs.
[0035] FIG. 7 is a sectional view of heat exchange elements having
ribs with irregular structural surfaces according to an embodiment.
As shown in FIG. 7, the heat exchange elements are multi-stacked in
a thickness direction. More specifically, FIG. 7 is a sectional
view taken along line I-I' of FIG. 5 in case that the heat exchange
elements of FIG. 5 are triply multi-stacked. The ribs of FIG. 7
each have an irregular structural surface in the form of uneven
portion 30 is provided on a surface of the ribs of FIG. 5 to
increase surface roughness. FIG. 8 is a sectional view of a rib
according to an embodiment with an irregular structural surface in
the form of an uneven portion having irregular shapes arranged
along a surface of the ribs 212 or 222.
[0036] Referring to FIGS. 7 and 8, the uneven portion 30, which may
be arranged regularly or irregularly on side surfaces (these may be
defined as "second surfaces") of the guide rib 212 and 222 of the
heat exchange element 20 according to the embodiment, is in contact
with the heat exchange gas. In addition, top and bottom surface of
the guide rib 212 and 222 (these may be defined as "first
surfaces") contact the heat exchange sheet.
[0037] More specifically, the uneven portion 30 may be provided
with a protrusion 31 which may protrude a predetermined distance
from the surface of the rib, and a recess 32 which may be recessed
a predetermined depth from the surface of the ribs. The protrusion
31 and the recess 32 may have various shapes, such as a circle, a
polygon, or other shape. The irregular arrangement and irregular
shape of the uneven portion 30 may be more effective for inducing a
turbulent flow. Further, a turbulent flow may be rapidly formed by
forming the protrusion 31 and the recess 32 in various sizes and
depths. Alternatively, a turbulent flow may be formed by forming a
scratch or scratches on the surface of the guide rib.
[0038] FIG. 9 is a perspective view of a heat exchange element
having ribs with irregular structural surfaces according to an
embodiment. Here, a velocity distribution 250 of heat exchange
gases flowing through each duct of the heat exchange element shows
a turbulent flow type distribution in which the velocity
distribution has a relatively flat profile around the center of the
duct and a thickness of a boundary layer is thin, unlike the
parabolic profile of FIG. 6. According to a heat exchange element
having the above configuration, it may be possible to minimize duct
resistance by suppressing a laminar flow and growth of a boundary
layer in airflow of outdoor and indoor air passing through a heat
exchanger. Therefore, heat exchange may be performed even with low
flow velocity and pressure because the pressure loss in the duct
may be minimized. Further, since the heat exchange gas may be
introduced/exhausted smoothly at a flow velocity as low as
possible, the heat exchange efficiency may be increased as
well.
[0039] Embodiments disclosed herein provide a heat exchanger for a
ventilating apparatus that may increase heat exchange efficiency
and reduce pressure loss by changing airflow of outdoor and indoor
air passing through a heat exchange element from a laminar flow to
a turbulent flow.
[0040] In a heat exchanger for a ventilating apparatus, ribs
coupled to a heat exchange sheet generally have smooth surfaces.
This smooth surface may have no adverse effect if the flow velocity
of the heat exchange gas is high enough. However, in the case that
the flow velocity of gas passing through the heat exchanger is low,
the smooth surface may cause a boundary layer to grow excessively
generating a laminar flow. When the heat exchange gas flow is a
laminar flow inside the heat exchanger, pressure loss is likely to
increase at an exhaust end because the flow velocity of the gas
decreases. Therefore, the heat exchange gas must be introduced at a
predetermined pressure and velocity higher than an appropriate flow
velocity range through an intake end for good heat exchange
ultimately, which leads to the decrease of heat exchange
efficiency.
[0041] Embodiments disclosed herein also provide a heat exchanger
for a ventilating apparatus that may increase heat exchange
efficiency by minimizing pressure loss, and thus, securing an
appropriate flow velocity of heat exchange gas even under a limited
supply pressure because outdoor air and indoor air passing through
the heat exchanger may flow in turbulent flow type as much as
possible. In one embodiment, a rib of a heat exchange element
defining a heat exchange gas and guiding a flow of the heat
exchange gas may include at least one first surface contacting a
heat exchange sheet, and at least one second surface contacting the
heat exchange gas. The second surface may be a structural surface
where a recess portion, a protrusion portion, or a combination of
the recess portion and the protrusion portion may be provided.
[0042] Further, the structural surface may correspond to a surface
with increased surface roughness on the second surface. The surface
roughness may be adjusted to a predetermined value that minimizes
pressure drop and velocity drop of the heat exchange gas, which is
possible by controlling a mean height of the structural
surface.
[0043] Also, the mean height of the structural surface may be
constant for inducing regular and smooth gas flow in a counter flow
section of the heat exchange gas, for example, in a section where
the rib has a straight shape. A protrusion portion or a recess
portion of the structural surface may act as a turbulent flow
generating portion to reduce a thickness of a boundary layer of gas
in the duct from an aspect of overall view rather than its specific
shape.
[0044] In another embodiment, a heat exchange element is provided
that includes a plurality of heat exchange sheets which are
multi-stacked, and a plurality of ribs arranged between the heat
exchange sheets to constitute ducts with the heat exchange sheets.
The ribs may include a structural surface including a recess
portion, a protrusion portion, or a combination of the recess
portion and the protrusion portion, which generates a turbulent
flow in a heat exchange gas flowing through the duct. The
structural surface may correspond to a surface increasing surface
roughness of the second surface. Further, a mean height of the
structural surface may correspond to a value that minimizes
internal pressure drop of the heat exchange gas. Alternatively, a
mean height of the structural surface may correspond to a value
that minimizes internal flow velocity drop of the heat exchange
gas.
[0045] With such a heat exchanger in which the heat exchange
elements in the shape of a duct having the above rib structure are
repeatedly stacked, it may be possible to make gases flow smoothly
at a flow velocity as low as possible for increasing the heat
exchange efficiency.
[0046] Any reference in this specification to "one embodiment," "an
embodiment," "example embodiment," etc., means that a particular
feature, structure, or characteristic described in connection with
the embodiment is included in at least one embodiment of the
invention. The appearances of such phrases in various places in the
specification are not necessarily all referring to the same
embodiment. Further, when a particular feature, structure, or
characteristic is described in connection with any embodiment, it
is submitted that it is within the purview of one skilled in the
art to effect such feature, structure, or characteristic in
connection with other ones of the embodiments.
[0047] Although embodiments have been described with reference to a
number of illustrative embodiments thereof, it should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the spirit and scope
of the principles of this disclosure. More particularly, various
variations and modifications ate possible in the component parts
and/or arrangements of the subject combination arrangement within
the scope of the disclosure, the drawings and the appended claims.
In addition to variations and modifications in the component parts
and/or arrangements, alternative uses will also be apparent to
those skilled in the art.
* * * * *