U.S. patent application number 12/442815 was filed with the patent office on 2010-03-25 for heat exchanging element.
This patent application is currently assigned to Panasonic Corporation. Invention is credited to Takuya Murayama, Makoto Sugiyama.
Application Number | 20100071887 12/442815 |
Document ID | / |
Family ID | 39229915 |
Filed Date | 2010-03-25 |
United States Patent
Application |
20100071887 |
Kind Code |
A1 |
Sugiyama; Makoto ; et
al. |
March 25, 2010 |
HEAT EXCHANGING ELEMENT
Abstract
A lamination type heat exchanging element for use in heat
exchange type ventilators and other air conditioning devices
eliminates drift in the air passages while maintaining its
structural strength, thereby providing high heat exchange
efficiency. The heat exchanging element also prevents airflow
leakage due to peeling between heat exchanger plates and other
components. To achieve this, rectification portions are provided
which eliminate drift in the air passages due to different
ventilation resistances of the flow channels caused by their
different flow channel lengths generated by flow channel division
portions, thereby forming a predetermined flow velocity
distribution in the counterflow regions.
Inventors: |
Sugiyama; Makoto; (Aichi,
JP) ; Murayama; Takuya; (Aichi, JP) |
Correspondence
Address: |
RATNERPRESTIA
P.O. BOX 980
VALLEY FORGE
PA
19482
US
|
Assignee: |
Panasonic Corporation
Osaka
JP
|
Family ID: |
39229915 |
Appl. No.: |
12/442815 |
Filed: |
August 20, 2007 |
PCT Filed: |
August 20, 2007 |
PCT NO: |
PCT/JP2007/066085 |
371 Date: |
March 25, 2009 |
Current U.S.
Class: |
165/166 |
Current CPC
Class: |
Y02B 30/56 20130101;
F24F 12/006 20130101; F28F 3/048 20130101; F28D 9/0037 20130101;
F28F 13/06 20130101; F28F 2250/108 20130101; Y02B 30/563 20130101;
F28F 2240/00 20130101 |
Class at
Publication: |
165/166 |
International
Class: |
F28F 3/08 20060101
F28F003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2006 |
JP |
2006 264050 |
Mar 13, 2007 |
JP |
2007 063183 |
Claims
1. A heat exchanging element for performing heat exchange by
circulating a primary airflow and a secondary airflow through
corresponding air passages alternately formed between a plurality
of heat exchanger plates laminated on each other with a
predetermined spacing, the heat exchanging element comprising:
counterflow regions in which the primary airflow and the secondary
airflow flow opposite to each other with the heat exchanger plates
therebetween; shield portions for preventing airflow leakage from
regions other than inlet ports and outlet ports of the primary
airflow and the secondary airflow in the air passages; flow channel
division portions for dividing each of the air passages into a
plurality of flow channels, the flow channels divided by the flow
channel division portions having different flow channel lengths
from each other; and rectification portions arranged in the air
passages, the rectification portions providing a predetermined flow
velocity distribution of the primary airflow and the secondary
airflow circulating through the counterflow regions in the flow
channels divided by the flow channel division portions.
2. The heat exchanging element of claim 1, wherein the
rectification portions are located in the air passages other than
the counterflow regions.
3. The heat exchanging element of claim 1, wherein the
rectification portions are ventilation resistance members shaped to
increase ventilation resistances of flow channels other than the
longest flow channel having the longest flow channel length of all
the flow channels divided by the flow channel division
portions.
4. The heat exchanging element of claim 3, wherein the
rectification portions are partially or wholly located in inlet
ports of the flow channels other than the longest flow channel so
that an opening area of each of the inlet ports of the flow
channels other than the longest flow channel can be smaller than an
opening area of an inlet port of the longest flow channel.
5. The heat exchanging element of claim 3, wherein the
rectification portions are partially or wholly located in outlet
ports of the flow channels other than the longest flow channel so
that an opening area of each of the outlet ports of the flow
channels other than the longest flow channel can be smaller than an
opening area of an outlet port of the longest flow channel.
6. The heat exchanging element of claim 3, wherein the
rectification portions are partially or wholly located in inlet
ports and outlet ports of the flow channels other than the longest
flow channel so that an opening area of each of the inlet ports and
an opening area of each of the outlet ports of the flow channels
other than the longest flow channel can be smaller than an opening
area of an inlet port and an opening area of an outlet port,
respectively, of the longest flow channel.
7. The heat exchanging element of claim 1, wherein the
rectification portions are shaped to decrease ventilation
resistances of flow channels having flow channel lengths longer
than an average flow channel length of the flow channels divided by
the flow channel division portions and to increase ventilation
resistances of flow channels having flow channel lengths shorter
than the average flow channel length.
8. The heat exchanging element of claim 7, wherein the
rectification portions are partially or wholly located in the inlet
ports of the flow channels so that an opening area of each of the
inlet ports of the flow channels having longer flow channel lengths
than the average flow channel length can be larger than an average
opening area of the inlet ports, and that an opening area of each
of the inlet ports of the flow channels having shorter flow channel
lengths than the average flow channel length can be smaller than
the average opening area of the inlet ports.
9. The heat exchanging element of claim 7, wherein the
rectification portions are partially or wholly located in the
outlet ports of the flow channels so that an opening area of each
of the outlet ports of the flow channels having longer flow channel
lengths than the average flow channel length can be larger than an
average opening area of the outlet ports, and that an opening area
of each of the outlet ports of the flow channels having shorter
flow channel lengths than the average flow channel length can be
smaller than the average opening area of the outlet ports.
10. The heat exchanging element of claim 7, wherein the
rectification portions are partially or wholly located in the inlet
ports and the outlet ports of the flow channels so that an opening
area of each of the inlet ports and an opening area of each of the
outlet ports of the flow channels having longer flow channel
lengths than the average flow channel length can be larger than an
average opening area of the inlet ports and an average opening area
of the outlet ports, respectively, and that an opening area of each
of the inlet ports and an opening area of each of the outlet ports
of the flow channels having shorter flow channel lengths than the
average flow channel length can be smaller than the average opening
area of the inlet ports and the average opening area of the outlet
ports, respectively.
11. The heat exchanging element of claim 1, wherein the flow
channel division portions are partially integrated with the
rectification portions, and the rectification portions are formed
by bending parts of the flow channel division portions in such a
manner that an opening area of flow channels having longer flow
channel lengths than an average flow channel length of the flow
channels divided by the flow channel division portions can be
larger than an average opening area, and that an opening area of
flow channels having shorter flow channel lengths than the average
flow channel length can be smaller than the average opening
area.
12. The heat exchanging element of claim 1, wherein the
rectification portions that increase ventilation resistances of the
flow channels divided by the flow channel division portions are
integrally formed with the flow channel division portions, the
rectification portions being formed as projections on surfaces of
the flow channel division portions that are in contact with the
flow channels.
13. The heat exchanging element of claim 1, wherein the
rectification portions that increase ventilation resistances of the
flow channels divided by the flow channel division portions are
integrally formed with the shield portions, the rectification
portions being formed as projections on some or all surfaces of the
shield portions that are in contact with opening sections of the
flow channels.
14. The heat exchanging element of claim 12, wherein the
projections are high on an opening side and low on an inner
side.
15. The heat exchanging element of claim 1, wherein the
rectification portions that increase ventilation resistances of the
flow channels divided by the flow channel division portions are
formed as projections on the heat exchanger plates.
16. The heat exchanging element of claim 15, wherein the
projections are formed between one side surface of the heat
exchanger plates and a reverse side of the flow channel division
portions.
17. The heat exchanging element of claim 1, wherein the heat
exchanger plates are integrally molded with resin frames using an
injection molding process so as to form a plurality of unit
elements, the heat exchanger plates being made of paper or resin
and having heat conductivity, moisture permeability, and a gas
shielding property, the resin frames being made of synthetic resin
and forming the air passages including the shield portions, the
flow channel division portions, and the rectification portions, and
the plurality of unit elements being laminated on each other.
18. The heat exchanging element of claim 1, wherein the heat
exchanger plates made of thermoplastic resin are each provided with
an uneven surface structure so as to form the shield portions, the
flow channel division portions, and the rectification portions
thereon so as to form the unit elements, the unit elements being
laminated on each other.
19. The heat exchanging element of claim 1, wherein the primary
airflow and the secondary airflow circulating the flow channels
divided by the flow channel division portions are subjected to heat
exchange in order of being at a right angle or an oblique angle to
each other, being opposite to each other, and being at a right
angle or an oblique angle to each other with the heat exchanger
plates therebetween.
20. The heat exchanging element of claim 1, wherein the heat
exchanging element has a rectangular picture plane in a lamination
direction, inlet ports of the primary airflow on a short side,
inlet ports of the secondary airflow on the other short side, and
outlet ports of the primary airflow and outlet ports of the
secondary airflow on a long side.
21. The heat exchanging element of claim 13, wherein the
projections are high on an opening side and low on an inner side.
Description
TECHNICAL FIELD
[0001] The present invention relates to a lamination type heat
exchanging element for use in heat exchange type ventilation fans
for domestic use, in heat exchange type ventilators for buildings
and other structures, and in other air conditioning devices.
BACKGROUND ART
[0002] A conventional heat exchanging element is described as
follows with reference to FIGS. 12A and 12B. FIG. 12A is a
schematic perspective view of a conventional heat exchanger. FIG.
12B is a partial sectional view of the conventional heat
exchanger.
[0003] As shown in FIG. 12A, conventional heat exchanger 101
includes pairs of plates 102, each pair being opposite to and
predeterminedly spaced from each other. Between each pair of plates
102 is arranged planer fin 104 having a corrugated cross section so
as to form parallel flow channels 103. Adjacent pairs of plates 102
are spaced by spacers 105 for guiding primary airflow "M" and
secondary airflow "N". Heat exchanger 101 further includes space
portions 106 on the downstream side of parallel flow channels 103
formed by fins 104. Fins 104 and spacers 105 are glued to plates
102.
[0004] Heat exchanger 101 includes inlet ports for receiving
primary and secondary airflows "M" and "N" on opposite sides
thereof, and outlet ports for discharging the airflows "M" and "N"
on a side perpendicular to the sides of the inlet ports. The side
opposite to the side of the outlet ports is closed. As shown in
FIG. 12B, fins 104 are formed at increasingly smaller pitch "P"
from one side (the left side in FIG. 12B) to the other (the right
side in FIG. 12B) on which the outlet ports are formed. This causes
a change in the cross sectional area of parallel flow channels 103,
thereby improving the heat exchange efficiency of heat exchanger
101.
[0005] In conventional heat exchanger 101, space portions 106
formed on the downstream side of parallel flow channels 103 cause
drift inside them because of the absence of components to control
airflow. In addition, space portions 106 are too low-strength to
maintain the spacing between adjacent plates 102 because of the
absence of components to maintain the spacing. This causes primary
and secondary airflows "M" and "N" circulating through heat
exchanger 101 to drift, thereby decreasing the heat exchange
efficiency. Thus, there is a demand for improving both strength and
heat exchange efficiency.
[0006] In order to reduce the cross sectional area of regions of
parallel flow channels 103 that are close to the side on which the
outlet ports are formed, the number of junctions between plates 102
and fins 104 is made larger than necessary to maintain the
structure of parallel flow channels 103. These junctions cause a
decrease in the effective area of the heat exchanger plates.
Moreover, the adhesive used to join plates 102 and fins 104
protrudes from the junctions, thereby significantly reducing the
effective area of plates 102, and hence, the heat exchange
efficiency. Thus, there is a demand for improving the heat exchange
efficiency.
[0007] In the case where parallel flow channels 103 are formed by
arranging independent components on plates 102 instead of fins 104,
the width of the flow channel having the largest pitch "P" of
parallel flow channels 103 cannot be made larger than the largest
pitch "P" with which to maintain the structure of parallel flow
channels 103. Furthermore, the design with increasingly smaller
pitch "P" causes the number of parallel flow channels 103 to be
larger than necessary to maintain the structure of parallel flow
channels 103, thereby significantly reducing the effective area of
plates 102, and hence the heat exchange efficiency. Thus, there is
a demand for improving the heat exchange efficiency.
[0008] Since fins 104 and spacers 105 are inserted into between
plates 102 and glued thereto, the distance between the top and
bottom of the corrugation of fins 104 and the thickness of spacers
105 should be highly uniform. However, in the actual production
process, it is difficult to make them uniform because fins 104 have
uneven pitch "P". Fins 104 having a large distance between the top
and bottom of the corrugation are crushed when glued to plates 102,
while fins 104 having a small distance cannot be properly glued to
plates 102. This makes it impossible to achieve the designed pitch
"P". Furthermore, the poor precision in the thickness direction
causes the heat exchanger plates to bend, and the difference in
height of pairs of plates 102 causes drift in the heat exchanging
element, thereby reducing the heat exchange efficiency. Thus, there
is a demand for improving the heat exchange efficiency.
[0009] Heat exchanger 101 includes low-strength space portions 106
and parallel flow channels 103 formed with pitch "P" increasingly
decreasing from one side to the other on which the outlet ports are
formed. As a result, heat exchanger 101 is subjected to variations
in strength and hence deformation. The deformation can cause
peeling between plates 102 and fins 104 or between plates 102 and
spacers 105, thereby increasing airflow leakage. Thus, there is a
demand for preventing airflow leakage.
[0010] Patent Document 1: Japanese Patent Examined Publication No.
S60-238689
SUMMARY OF THE INVENTION
[0011] In view of the conventional problems, it is an object of the
present invention to provide a heat exchanging element that
eliminates drift in air passages while maintaining its structural
strength, thereby providing high heat exchange efficiency and that
also prevents airflow leakage due to peeling between the heat
exchanger plates and other components.
[0012] The heat exchanging element according to the present
invention performs heat exchange by circulating a primary airflow
and a secondary airflow through their corresponding air passages
alternately formed between a plurality of heat exchanger plates
laminated on each other with a predetermined spacing. The heat
exchanging element includes counterflow regions in which the
primary airflow and the secondary airflow flow opposite to each
other with the heat exchanger plates therebetween. The heat
exchanging element further includes shield portions for preventing
airflow leakage from regions other than the inlet and outlet ports
of the primary and secondary airflows in the air passages; flow
channel division portions for dividing each of the air passages
into a plurality of flow channels, the flow channels divided by the
flow channel division portions having different flow channel
lengths from each other; and rectification portions arranged in the
air passages, the rectification portions providing a predetermined
flow velocity distribution of the primary and secondary airflows
circulating through the counterflow regions in the flow channels
divided by the flow channel division portions.
[0013] Thus, the present invention provides a heat exchanging
element that eliminates drift in the air passages while maintaining
its structural strength, thereby providing high heat exchange
efficiency, and that also prevents airflow leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic perspective view of a heat exchanging
element according to a first embodiment of the present
invention.
[0015] FIG. 2A is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction X
of FIG. 1.
[0016] FIG. 2B is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction Y
of FIG. 1.
[0017] FIG. 3 is a schematic production flowchart of the heat
exchanging element according to the first embodiment of the present
invention.
[0018] FIG. 4 is a schematic perspective view of a heat exchanging
element according to a second embodiment of the present
invention.
[0019] FIG. 5A is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction X
of FIG. 4.
[0020] FIG. 5B is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction Y
of FIG. 4.
[0021] FIG. 6 is a schematic perspective view of a heat exchanging
element according to a third embodiment of the present
invention.
[0022] FIG. 7 is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction X
of FIG. 6.
[0023] FIG. 8 is a schematic production flowchart of the heat
exchanging element according to the third embodiment of the present
invention.
[0024] FIG. 9 is a schematic perspective view of a heat exchanging
element according to a fourth embodiment of the present
invention.
[0025] FIG. 10A is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction X
of FIG. 9.
[0026] FIG. 10B is an enlarged schematic perspective view of one
unit element as a component of the heat exchanging element seen in
the direction X of FIG. 9.
[0027] FIG. 10C is an enlarged schematic perspective view of the
unit element taken along line A-A of FIG. 10B.
[0028] FIG. 11 is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction Y
of FIG. 9.
[0029] FIG. 12A is a schematic perspective view of a conventional
heat exchanger.
[0030] FIG. 12B is a partial sectional view of the conventional
heat exchanger.
REFERENCE MARKS IN THE DRAWINGS
[0031] 1a, 1b, 1c, 1d heat exchanging element [0032] 2a, 2b, 2c,
2d, 2e, 2f resin frame [0033] 3a, 3b, 3c, 3d heat exchanger plate
[0034] 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h unit element [0035] 5A, 5B,
5C, 5D, 5E, 5F, 5G, 5H air passage [0036] 6a, 6b, 6c, 6d, 6e, 6f,
6g, 6h shield portion [0037] 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h flow
channel division portion [0038] 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h
rectification portion [0039] 9a, 9b, 9c, 9d, 9e, 9f engagement
projection [0040] 10a, 10b, 10c, 10d, 10e, 10f engagement recess
[0041] 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h inlet port [0042]
12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h outlet port [0043] 13a, 13b,
13c, 13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q,
13r, 13s, 13t, 13u, 13v, 13w, 13x, 13y, 13z flow channel [0044]
14a, 14b, 14c, 14d counterflow region [0045] 15a, 15b cutting step
[0046] 16a, 16b molding step [0047] 17a, 17b laminating step [0048]
18a, 18b bonding step [0049] 19a, 19b spaced projection
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] A heat exchanging element according to the present invention
performs heat exchange by circulating a primary airflow and a
secondary airflow through their corresponding air passages
alternately formed between a plurality of heat exchanger plates
laminated on each other with a predetermined spacing, the heat
exchanging element including: counterflow regions in which the
primary and secondary airflows flow opposite to each other with the
heat exchanger plates therebetween; shield portions for preventing
airflow leakage from regions other than the inlet and outlet ports
of the primary and secondary airflows in the air passages; flow
channel division portions for dividing each of the air passages
into a plurality of flow channels, the flow channels divided by the
flow channel division portions having different flow channel
lengths from each other; and rectification portions arranged in the
air passages, the rectification portions providing a predetermined
flow velocity distribution of the primary and secondary airflows
circulating through the counterflow regions in the flow channels
divided by the flow channel division portions.
[0051] The heat exchanging element has less drift in the air
passages because the air passages are each divided into a plurality
of flow channels by the flow channel division portions. The
different flow channel lengths of the flow channels divided by the
flow channel division portions result in their different
ventilation resistances, thereby causing drift in the air passages.
The drift, however, is eliminated by providing the rectification
portions in the air passages so as to change the ventilation
resistances of the flow channels and to form a predetermined flow
velocity distribution in the counterflow regions. This results in
providing high heat exchange efficiency while maintaining the
structural strength of the heat exchanging element. The flow
channel division portions play a role in maintaining both the
spacing between the heat exchanger plates and the strength of the
heat exchanging element, so that the spacing between the heat
exchanger plates can be kept uniform. This prevents drift due to
uneven spacing between the heat exchanger plates, which have a low
structural strength, thereby providing high heat exchange
efficiency while maintaining the structural strength of the heat
exchanging element.
[0052] In the heat exchanging element, the rectification portions
may be located somewhere in the air passages other than the
counterflow regions.
[0053] Thus locating the rectification portions somewhere in the
air passages other than the counterflow regions having the greatest
effect on the heat exchange efficiency of the heat exchanging
element can change the ventilation resistances of the flow channels
divided by the flow channel division portions while reducing the
effect on the heat exchange efficiency. This eliminates drift in
the air passages due to different ventilation resistances of the
flow channels caused by their different flow channel lengths
generated by the flow channel division portions, thereby forming a
predetermined flow velocity distribution in the counterflow
regions. This results in providing high heat exchange
efficiency.
[0054] In the heat exchanging element, the rectification portions
may be ventilation resistance members shaped to increase
ventilation resistances of the flow channels other than the longest
flow channel having the longest flow channel length of all the flow
channels divided by the flow channel division portions.
[0055] The longest flow channel has a higher ventilation resistance
than the other flow channels. Therefore, the flow channels other
than the longest flow channel are provided with the rectification
portions, which are the ventilation resistance members to increase
their ventilation resistances. This eliminates drift in the air
passages due to different ventilation resistances of the flow
channels caused by their different flow channel lengths, thereby
forming a predetermined flow velocity distribution in the
counterflow regions. This results in providing high heat exchange
efficiency.
[0056] In the heat exchanging element, the rectification portions
may be partially or wholly located in the inlet ports of the flow
channels other than the longest flow channel so that the opening
area of each of the inlet ports of the flow channels other than the
longest flow channel can be smaller than the opening area of the
inlet port of the longest flow channel.
[0057] The longest flow channel has a higher ventilation resistance
than the other flow channels. Therefore, the flow channels other
than the longest flow channel are provided in their inlet ports
with the rectification portions so as to reduce the opening area of
each of the inlet ports including the rectification portions,
thereby increasing their ventilation resistances. This eliminates
drift in the air passages due to different ventilation resistances
of the flow channels caused by their different flow channel
lengths, thereby forming a predetermined flow velocity distribution
in the counterflow regions. This results in providing high heat
exchange efficiency.
[0058] In the heat exchanging element, the rectification portions
may be partially or wholly located in the outlet ports of the flow
channels other than the longest flow channel so that the opening
area of each of the outlet ports of the flow channels other than
the longest flow channel can be smaller than the opening area of
the outlet port of the longest flow channel.
[0059] The longest flow channel has a higher ventilation resistance
than the other flow channels. Therefore, the flow channels other
than the longest flow channel are provided in their outlet ports
with the rectification portions so as to reduce the opening area of
each of the outlet ports including the rectification portions,
thereby increasing their ventilation resistances. This eliminates
drift in the air passages due to different ventilation resistances
of the flow channels caused by their different flow channel
lengths, thereby forming a predetermined flow velocity distribution
in the counterflow regions. This results in providing high heat
exchange efficiency.
[0060] In the heat exchanging element, the rectification portions
may be partially or wholly located in the inlet and outlet ports of
the flow channels other than the longest flow channel so that the
opening area of each of the inlet ports and the opening area of
each of the outlet ports of the flow channels other than the
longest flow channel can be smaller than the opening area of the
inlet port and the opening area of the outlet port, respectively,
of the longest flow channel.
[0061] The longest flow channel has a higher ventilation resistance
than the other flow channels. Therefore, the flow channels other
than the longest flow channel are provided in their inlet and
outlet ports with the rectification portions so as to reduce the
opening area of each of the inlet ports and the opening area of
each of the outlet ports including the rectification portions,
thereby increasing their ventilation resistances. This eliminates
drift in the air passages due to different ventilation resistances
of the flow channels caused by their different flow channel
lengths, thereby forming a predetermined flow velocity distribution
in the counterflow regions. This results in providing high heat
exchange efficiency.
[0062] In the heat exchanging element, the rectification portions
may be shaped to decrease ventilation resistances of the flow
channels having flow channel lengths longer than an average flow
channel length of the flow channels divided by the flow channel
division portions and to increase ventilation resistances of the
flow channels having flow channel lengths shorter than the average
flow channel length.
[0063] Thus, the rectification portions are provided so as to
decrease ventilation resistances of the flow channels having flow
channel lengths longer than the average flow channel length, and to
increase ventilation resistances of the flow channels having flow
channel lengths shorter than the average flow channel length. This
increases the flow velocities of the flow channels having flow
channel lengths longer than the average flow channel length and
decreases the flow velocities of the flow channels having flow
channel lengths shorter than the average flow channel length. This
eliminates drift in the air passages due to different ventilation
resistances of the flow channels caused by their different flow
channel lengths generated by the flow channel division portions,
thereby forming a predetermined flow velocity distribution in the
counterflow regions. This results in providing high heat exchange
efficiency.
[0064] In the heat exchanging element, the rectification portions
may be partially or wholly located in the inlet ports of the flow
channels so that the opening area of each of the inlet ports of the
flow channels having longer flow channel lengths than the average
flow channel length can be larger than the average opening area of
the inlet ports, and that the opening area of each of the inlet
ports of the flow channels having shorter flow channel lengths than
the average flow channel length can be smaller than the average
opening area of the inlet ports.
[0065] The flow channels having flow channel lengths longer than
the average flow channel length relatively have large ventilation
resistances and low flow velocities. The flow channels having flow
channel lengths shorter than the average flow channel length
relatively have small ventilation resistances and high flow
velocities. However, the provision of the rectification portions in
the inlet ports allows the opening area of each of the inlet ports
of the flow channels having flow channel lengths longer than the
average flow channel length to be larger than the average opening
area of the inlet ports, thereby decreasing their ventilation
resistances. The provision of the rectification portions in the
inlet ports also allows the opening area of each of the inlet ports
of the flow channels having flow channel lengths shorter than the
average flow channel length to be smaller than the average opening
area of the inlet ports, thereby increasing their ventilation
resistances. This eliminates drift in the air passages due to
different ventilation resistances of the flow channels caused by
their different flow channel lengths generated by the flow channel
division portions, thereby forming a predetermined flow velocity
distribution in the counterflow regions. This results in providing
high heat exchange efficiency.
[0066] In the heat exchanging element, the rectification portions
may be partially or wholly located in the outlet ports of the flow
channels so that the opening area of each of the outlet ports of
the flow channels having longer flow channel lengths than the
average flow channel length can be larger than the average opening
area of the outlet ports, and that the opening area of each of the
outlet ports of the flow channels having shorter flow channel
lengths than the average flow channel length can be smaller than
the average opening area of the outlet ports.
[0067] The flow channels having flow channel lengths longer than
the average flow channel length relatively have large ventilation
resistances and low flow velocities. The flow channels having flow
channel lengths shorter than the average flow channel length
relatively have small ventilation resistances and high flow
velocities. However, the provision of the rectification portions in
the outlet ports allows the opening area of each of the outlet
ports of the flow channels having flow channel lengths longer than
the average flow channel length to be larger than the average
opening area of the outlet ports, thereby decreasing their
ventilation resistance. The provision of the rectification portions
in the outlet ports also allows the opening area of each of the
outlet ports of the flow channels having flow channel lengths
shorter than the average flow channel length to be smaller than the
average opening area of the outlet ports, thereby increasing their
ventilation resistance. This eliminates drift in the air passages
due to different ventilation resistances of the flow channels
caused by their different flow channel lengths generated by the
flow channel division portions, thereby forming a predetermined
flow velocity distribution in the counterflow regions. This results
in providing high heat exchange efficiency.
[0068] In the heat exchanging element, the rectification portions
may be partially or wholly located in the inlet and outlet ports of
the flow channels so that the opening area of each of the inlet
ports and the opening area of each of the outlet ports of the flow
channels having longer flow channel lengths than the average flow
channel length can be larger than the average opening area of the
inlet ports and the average opening area of the outlet ports,
respectively, and that the opening area of each of the inlet ports
and the opening area of each of the outlet ports of the flow
channels having shorter flow channel lengths than the average flow
channel length can be smaller than the average opening area of the
inlet ports and the average opening area of the outlet ports,
respectively.
[0069] The flow channels having flow channel lengths longer than
the average flow channel length relatively have large ventilation
resistances and low flow velocities. The flow channels having flow
channel lengths shorter than the average flow channel length
relatively have small ventilation resistances and high flow
velocities. However, the provision of the rectification portions in
the inlet and outlet ports allows the opening area of each of the
inlet ports and the opening area of each of the outlet ports of the
flow channels having flow channel lengths longer than the average
flow channel length to be larger than the average opening area of
the inlet ports and the average opening area of the outlet ports,
respectively, thereby decreasing their ventilation resistances. The
provision of the rectification portions in the inlet and outlet
ports also allows the opening area of each of the inlet ports and
the opening area of each of the outlet ports of the flow channels
having flow channel lengths shorter than the average flow channel
length to be smaller than the average opening area of the inlet
ports and the average opening area of the outlet ports,
respectively, thereby increasing their ventilation resistances.
This eliminates drift in the air passages due to different
ventilation resistances of the flow channels caused by their
different flow channel lengths generated by the flow channel
division portions, thereby forming a predetermined flow velocity
distribution in the counterflow regions. This results in providing
high heat exchange efficiency.
[0070] In the heat exchanging element, the flow channel division
portions may be partially integrated with the rectification
portions, and the rectification portions may be formed by bending
parts of the flow channel division portions in such a manner that
the opening area of flow channels having longer flow channel
lengths than the average flow channel length of the flow channels
divided by the flow channel division portions can be larger than
the average opening area, and that the opening area of flow
channels having shorter flow channel lengths than the average flow
channel length can be smaller than the average opening area.
[0071] The flow channels having flow channel lengths longer than
the average flow channel length relatively have large ventilation
resistances and low flow velocities. The flow channels having flow
channel lengths shorter than the average flow channel length
relatively have small ventilation resistances and high flow
velocities. However, the opening area of the flow channels having
flow channel lengths longer than the average flow channel length
can be larger than the average opening area so as to decrease their
ventilation resistances, thereby increasing the flow velocities.
The opening area of the flow channels having flow channel lengths
shorter than the average flow channel length can be smaller than
the average opening area so as to increase their ventilation
resistances, thereby decreasing the flow velocities. The
rectification portions, which are formed by bending parts of the
flow channel division portions, hardly decrease the effective area
of the heat exchanger plates or do not decrease the total opening
area of the inlet ports or the outlet ports. This eliminates drift
in the air passages due to different ventilation resistances of the
flow channels caused by their different flow channel lengths
generated by the flow channel division portions, thereby forming a
predetermined flow velocity distribution in the counterflow
regions. This results in providing high heat exchange
efficiency.
[0072] In the heat exchanging element, the rectification portions
that increase ventilation resistances of the flow channels divided
by the flow channel division portions may be integrally formed with
the flow channel division portions, the rectification portions
being formed as projections on the surfaces of the flow channel
division portions that are in contact with the flow channels.
[0073] Thus forming the projections as the rectification portion on
the surfaces of the flow channel division portions that are in
contact with the flow channels makes it possible to determine the
ventilation resistance of each flow channel freely. This eliminates
drift in the air passages due to different ventilation resistances
of the flow channels caused by their different flow channel lengths
generated by the flow channel division portions, thereby forming a
predetermined flow velocity distribution in the counterflow
regions. Furthermore, the projections eliminate drift in each flow
channel, thereby providing high heat exchange efficiency.
[0074] In the heat exchanging element, the rectification portions
that increase ventilation resistances of the flow channels divided
by the flow channel division portions may be integrally formed with
the shield portions, the rectification portions being formed as
projections on some or all surfaces of the shield portions that are
in contact with the opening sections of the flow channels.
[0075] Thus forming the projections on the surfaces of the shield
portions that are in contact with the opening sections makes it
possible to determine the ventilation resistance of each flow
channel freely. This eliminates drift in the air passages due to
different ventilation resistances of the flow channels caused by
their different flow channel lengths generated by the flow channel
division portions, thereby forming a predetermined flow velocity
distribution in the counterflow regions. Furthermore, the
projections eliminate drift in each flow channel, thereby providing
high heat exchange efficiency.
[0076] In the heat exchanging element, the projections may be high
on the opening side and low on the inner side.
[0077] Making the projections high on the opening side and low on
the inner side can eliminate drift in the air passages while
minimizing airflow disorder due to abrupt expansion or contraction
of the flow channels, thereby forming a predetermined flow velocity
distribution in the counterflow regions. Furthermore, the
projections eliminate drift in each flow channel, thereby providing
high heat exchange efficiency.
[0078] In the heat exchanging element, the rectification portions
that increase ventilation resistances of the flow channels divided
by the flow channel division portions may be formed as projections
on the heat exchanger plates.
[0079] Thus forming the projections on the heat exchanger plates
makes it possible to determine the ventilation resistance of each
flow channel freely. This eliminates drift in the air passages due
to different ventilation resistances of the flow channels caused by
their different flow channel lengths generated by the flow channel
division portions, thereby forming a predetermined flow velocity
distribution in the counterflow regions. Furthermore, the
projections eliminate drift in each flow channel, thereby providing
high heat exchange efficiency.
[0080] In the heat exchanging element, the projections may be
formed between one side surface of the heat exchanger plates and a
reverse side of the flow channel division portions.
[0081] Thus forming the projections between one side surface of the
heat exchanger plates and a reverse side of the flow channel
division portions makes it possible to determine the ventilation
resistance of each flow channel freely without decreasing the
effective area of the heat exchanger plates. This eliminates drift
in the air passages due to different ventilation resistances of the
flow channels caused by their different flow channel lengths
generated by the flow channel division portions, thereby forming a
predetermined flow velocity distribution in the counterflow
regions. Furthermore, the projections eliminate drift in each flow
channel, thereby providing high heat exchange efficiency.
[0082] In the heat exchanging element, the heat exchanger plates
may be integrally molded with resin frames using an injection
molding process so as to form a plurality of unit elements, the
heat exchanger plates being made of paper or resin and having heat
conductivity, moisture permeability, and a gas shielding property,
the resin frames being made of synthetic resin and forming the air
passages including the shield portions, the flow channel division
portions, and the rectification portions, and the plurality of unit
elements being laminated on each other.
[0083] Each of the heat exchanger plates is inserted into an
injection mold for molding resin frames, and molten resin is
injected into the mold so that resin frames are integrally molded
with the heat exchanger plate. This improves the joint strength
between the heat exchanger plate and the resin frames each having
the shield portions, the flow channel division portions, and the
rectification portions. As a result, this prevents airflow leakage
due to peeling between the heat exchanger plate and the resin
frames. The use of the injection molding process to integrally mold
the shield portions, the flow channel division portions, and the
rectification portions provides high-precision spacing between the
heat exchanger plates in the thickness direction. This enables the
heat exchanging element to maintain its strength, thus preventing
bending of the heat exchanger plates, which may be caused if the
precision in the thickness direction is low while the unit elements
are alternately laminated, and also preventing drift in the air
passages which may be caused when the unit elements do not have a
uniform height. This results in providing high heat exchange
efficiency.
[0084] In the heat exchanging element, the heat exchanger plates
made of thermoplastic resin may be each provided with an uneven
surface structure so as to form the unit elements, the unit
elements being laminated on each other.
[0085] The unit elements are formed by providing an uneven surface
structure on the heat exchanger plates of thermoplastic resin by
vacuum forming or the like. The heat exchanger plates, the shield
portions, the flow channel division portions, and the rectification
portions are all made of the same material. This prevents peeling
between the heat exchanger plates and other components, and hence,
airflow leakage due to peeling. The integral molding of the shield
portions, the flow channel division portions, and the rectification
portions provides high-precision spacing between the heat exchanger
plates in the thickness direction. This enables the heat exchanging
element to maintain its strength, thus preventing bending of the
heat exchanger plates, which may be caused if the precision in the
thickness direction is low while the unit elements are alternately
laminated, and also preventing drift in the air passages which may
be caused when the unit elements do not have a uniform height. This
results in providing high heat exchange efficiency.
[0086] In the heat exchanging element, the primary airflow and the
secondary airflow circulating the flow channels divided by the flow
channel division portions may be subjected to heat exchange in
order of being at a right angle or an oblique angle to each other,
being opposite to each other, and being at a right angle or an
oblique angle to each other with the heat exchanger plates
therebetween.
[0087] The presence of the regions in which the primary airflow and
the secondary airflow flow opposite to each other with the heat
exchanger plates therebetween provides high heat exchange
efficiency.
[0088] In the heat exchanging element, the heat exchanging element
may have a rectangular picture plane in the lamination direction,
the inlet ports of the primary airflow on the short side, the inlet
ports of the secondary airflow on the other short side, and the
outlet ports of the primary airflow and the outlet ports of the
secondary airflow on the long side.
[0089] The primary airflow is drawn in from the short side and
drawn out from a portion of the long side. The secondary airflow is
drawn in from the short side opposite to the side on which the
inlet ports of the primary airflow are formed, and is drawn out
from a portion of the long side on which the outlet ports of the
primary airflow are formed. The rectangular picture plane of the
heat exchanging element in the lamination direction allows the
primary and secondary airflows to flow opposite to each other in
long regions with the heat exchanger plates therebetween, thereby
providing high heat exchange efficiency.
[0090] The embodiments of the present invention will be described
as follows with reference to drawings.
First Embodiment
[0091] FIG. 1 is a schematic perspective view of a heat exchanging
element according to a first embodiment of the present invention.
FIG. 2A is a schematic perspective view of one unit element as a
component of the heat exchanging element seen in a direction X of
FIG. 1. FIG. 2B is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction Y
of FIG. 1. FIG. 3 is a schematic production flowchart of the heat
exchanging element.
[0092] As shown in FIGS. 1, 2A, and 2B, heat exchanging element 1a
includes unit elements 4a and unit elements 4b alternately
laminated on each other. Each unit element 4a includes heat
exchanger plate 3a integrally molded with resin frame 2a. Each unit
element 4b includes heat exchanger plate 3a integrally molded with
resin frame 2b. Each heat exchanger plate 3a includes air passage
5A on its top surface and air passage 5B on its bottom surface.
Heat exchanging element 1a circulates primary airflow "A" through
air passage 5A, and secondary airflow "B" through air passage 5B,
thereby enabling heat exchange between primary and secondary
airflows "A" and "B" via heat exchanger plates 3a.
[0093] Unit elements 4a are each formed by integrally molding heat
exchanger plate 3a with resin frame 2a including shield portions
6a, flow channel division portions 7a, rectification portions 8a,
engagement projections 9a, and engagement recesses 10a. Unit
elements 4b are each formed by integrally molding heat exchanger
plate 3a with resin frame 2b including shield portions 6b, flow
channel division portions 7b, rectification portions 8b, engagement
projections 9b, and engagement recesses 10b. Unit elements 4a and
4b have a picture plane with a long side of 145 mm and a short side
of 65 mm in the lamination direction.
[0094] The alternate lamination of unit elements 4a and unit
elements 4b enables heat exchanging element 1a to have inlet ports
11a and outlet ports 12a of primary airflow "A" and inlet ports 11b
and outlet ports 12b of secondary airflow "B". Air passage 5A is
divided into three flow channels 13a, 13b, and 13c by flow channel
division portions 7a. Air passage 5B is divided into three flow
channels 13d, 13e, and 13f by flow channel division portions
7b.
[0095] Shield portions 6a and 6b are arranged on the top and bottom
surfaces, respectively, of heat exchanger plate 3a so as to form
the outer frames excluding inlet ports 11a, 11b and outlet ports
12a, 12b. The linear portions of shield portions 6a and 6b have a
width of 4 mm and a height of 0.75 mm.
[0096] Flow channel division portions 7a and 7b, which have a width
of 1.5 mm and a height of 0.75 mm, are arranged on the top and
bottom surfaces, respectively, of heat exchanger plate 3a so as to
fit each other when unit elements 4a and 4b are laminated.
Rectification portions 8a, which have a width of 1.5 mm and a
height of 0.75 mm, are integrally formed with flow channel division
portions 7a by bending flow channel division portions 7a in the
vicinity of inlet ports 11a, 11b and outlet ports 12a, 12b.
Rectification portions 8b, which have a width of 1.5 mm and a
height of 0.75 mm, are integrally formed with flow channel division
portions 7b by bending flow channel division portions 7b in the
vicinity of inlet ports 11a, 11b and outlet ports 12a, 12b. As a
result, rectification portions 8a and 8b are conformed to each
other when unit elements 4a and 4b are laminated.
[0097] Rectification portions 8a and 8b are formed by bending flow
channel division portions 7a and 7b in the following conditions.
The opening area of each of inlet and outlet ports 11a, 12a of flow
channel 13a, and the opening area of each of inlet and outlet ports
11b, 12b of flow channel 13d which have a flow channel length
longer than the average flow channel length are made larger than
the average opening area. The opening area of each of inlet and
outlet ports 11a, 12a of flow channels 13b, 13c and the opening
area of each of inlet and outlet ports 11b, 12b of flow channels
13e, 13f which have flow channel lengths shorter than the average
flow channel length are made smaller than the average opening
area.
[0098] The "flow channel length" in the present specification
indicates the center-line length of each flow channel. The flow
channel lengths in the present embodiment are as follows: flow
channels 13a and 13d: 182 mm, flow channels 13b and 13e: 142 mm,
and flow channels 13c and 13f: 105 mm. The average flow channel
length is 143 mm. The "opening area" in the present specification
indicates the area of the inlet or outlet port of one flow channel.
The "total opening area" indicates the sum of the opening areas of
the inlet ports or outlet ports of the flow channels of one unit
element. The "average opening area" indicates an area obtained by
dividing the total opening area by the number of flow channels. The
opening areas in the present embodiment are as follows: inlet ports
11a and 11b respectively of flow channel 13a and 13d: 40.5
mm.sup.2; outlet ports 12a and 12b respectively of flow channels
13a and 13d: 36 mm.sup.2; inlet ports 11a and 11b respectively of
flow channels 13b and 13e: 24 mm.sup.2; outlet ports 12a and 12b
respectively of flow channels 13b and 13e: 25.5 mm.sup.2; inlet
ports 11a and 11b respectively of flow channels 13c and 13f: 16.5
mm.sup.2; and outlet ports 12a and 12b respectively of flow
channels 13c and 13f: 19.5 mm.sup.2. The total opening area of
inlet ports 11a, 11b and the total opening area of outlet ports
12a, 12b are both 81 mm.sup.2. The average opening area of inlet
ports 11a, 11b, and the average opening area of outlet ports 12a,
12b are both 27 mm.sup.2.
[0099] Engagement projections 9a and 9b, which have a width of 1.5
mm and a height of 0.4 mm, are arranged on shield portions 6a and
6b, respectively formed on the top surface of each heat exchanger
plate 3a. Engagement recesses 10a and 10b, which have a width of
1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6a
and 6b, respectively formed on the bottom surface of each heat
exchanger plate 3a. When unit elements 4a and 4b are alternately
laminated, engagement projections 9a and engagement recesses 10b
are engaged with each other, and engagement projections 9b and
engagement recesses 10a are engaged with each other.
[0100] Heat exchanging element 1a is a counter flow type in which
primary and secondary airflows "A" and "B" flow at a right angle or
an oblique angle to each other with heat exchanger plates 3a
therebetween in the vicinity of inlet ports 11a, 11b and outlet
ports 12a, 12b, and flow opposite to each other with heat exchanger
plates 3a therebetween in the center. The regions in which primary
and secondary airflows "A" and "B" flow opposite to each other with
heat exchanger plates 3a therebetween are referred to as
counterflow regions 14a. In counterflow regions 14a, flow channels
13a-13f have a width of 18 mm.
[0101] Resin frames 2a and 2b are formed of a thermoplastic resin
such as polystyrene (ABS, AS, or PS) or polyolefin (PP or PE). Heat
exchanger plates 3a are cut into a rectangular shape having a long
side of 143 mm and a short side of 63 mm. The thickness is 0.2 to
0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3a
can be made of Japanese paper, flame retardant paper, or
specially-treated paper having heat conductivity, moisture
permeability, and a gas shielding property, or can be a
moisture-permeable film or a resin sheet or film having only heat
conductivity such as polyester, polystyrene (ABS, AS, or PS), or
polyolefin (PP or PE).
[0102] As shown in FIG. 3, the production process of heat
exchanging element 1a includes cutting step 15a, molding step 16a,
laminating step 17a, and bonding step 18a performed in this order.
Cutting step 15a cuts heat exchanger plates 3a into shape. Molding
step 16a integrally molds heat exchanger plate 3a with resin frame
2a so as to form unit element 4a, and also integrally molds heat
exchanger plate 3a with resin frame 2b so as to form unit element
4b. Laminating step 17a alternately laminates unit elements 4a and
unit elements 4b on each other. Bonding step 18a bonds unit
elements 4a and 4b thus laminated.
[0103] Cutting step 15a of the present embodiment cuts each heat
exchanger plate 3a into a rectangular shape having a long side of
143 mm and a short side of 63 mm.
[0104] Molding step 16a inserts heat exchanger plate 3a into an
injection mold, injects molten resin into the mold, and solidifies
the molten resin so as to form resin frames 2a and 2b. Resin frame
2a is joined to heat exchanger plate 3a, and resin frame 2b is
joined to heat exchanger plate 3a so as to form unit elements 4a
and 4b.
[0105] Laminating step 17a laminates unit elements 4a and unit
elements 4b alternately on each other so that engagement
projections 9a are engaged with engagement recesses 10b, and
engagement projections 9b are engaged with engagement recesses
10a.
[0106] Bonding step 18a melts the four corners of unit elements 4a
and 4b thus laminated, and parts of the edges of the regions where
inlet ports 11a, 11b or outlet ports 12a, 12b are not formed.
Bonding step 18a then solidifies the molten resin so as to join
unit elements 4a and 4b thus laminated. The resin can be melted by
ultrasonic welding.
[0107] With the above structure, heat exchanging element 1a allows
primary and secondary airflows "A" and "B" to circulate through
their corresponding air passages arranged alternately to prevent
airflows "A" and "B" from being mixed with each other. Primary and
secondary airflows "A" and "B" flow at a right angle or an oblique
angle to each other with heat exchanger plates 3a therebetween in
the vicinity of inlet ports 11a, 11b and outlet ports 12a, 12b, and
flow opposite to each other with heat exchanger plates 3a
therebetween in the center, that is, counterflow regions 14a.
Primary airflow "A" is drawn in from the short side and drawn out
from a portion of the long side. Secondary airflow "B" is drawn in
from the short side opposite to the side on which inlet ports 11a
of primary airflow "A" are formed, and is drawn out from a portion
of the long side on which outlet ports 12a of primary airflow "A"
are formed. The rectangular picture plane of heat exchanging
element 1a in the lamination direction allows primary and secondary
airflows "A" and "B" to flow opposite to each other in large
counterflow regions 14a with heat exchanger plates 3a therebetween,
thereby providing high heat exchange efficiency.
[0108] Shield portions 6a, 6b, flow channel division portions 7a,
7b, and rectification portions 8a, 8b play a role in maintaining
both the spacing between heat exchanger plates 3a and the strength
of heat exchanging element 1a, so that the spacing between heat
exchanger plates 3a can be kept uniform. This prevents drift due to
uneven spacing between heat exchanger plates 3a, which may be
caused when the structural strength is low. As a result, high heat
exchange efficiency can be provided while maintaining the
structural strength.
[0109] Air passages 5A and 5B are divided into flow channels
13a-13c and 13d-13f, respectively, by flow channel division
portions 7a and 7b so as to reduce the drift in air passages 5A and
5B. Flow channels 13a-13c and 13d-13f divided by flow channel
division portions 7a and 7b, respectively, have different flow
channel lengths, and hence, different ventilation resistances,
thereby causing drift. The drift, however, is eliminated by
providing rectification portions 8a and 8b in air passages 5A and
5B so as to change the ventilation resistances of flow channels
13a-13f. Furthermore, a predetermined flow velocity distribution is
formed in counterflow regions 14a so as to provide high heat
exchange efficiency. The "predetermined flow velocity distribution"
indicates approximately uniform flow velocities of flow channels
13a-13f in counterflow regions 14a. However, the flow velocity
distribution differs depending on the design condition of the heat
exchange type ventilation fan, and is properly changed depending on
the trade off between the size of heat exchanging element 1a and
the required ventilation resistance. Therefore, the flow velocity
distribution may be designed so that the flow channel having the
longest flow length has the highest velocity, instead of that all
flow channels have approximately uniform velocities.
[0110] In air passages 5A and 5B, rectification portions 8a and 8b
are located somewhere other than counterflow regions 14a having the
greatest effect on the heat exchange efficiency of heat exchanging
element 1a. This eliminates drift in air passages 5A and 5B due to
different ventilation resistances of flow channels 13a-13f caused
by their different flow channel lengths generated by flow channel
division portions 7a and 7b, thereby forming a predetermined flow
velocity distribution in counterflow regions 14a. This results in
providing high heat exchange efficiency.
[0111] Flow channels 13a and 13d having a flow channel length
longer than the average flow channel length relatively have a large
ventilation resistance and a low flow velocity. Flow channels 13b,
13c, 13e, and 13f having flow channel lengths shorter than the
average flow channel length relatively have small ventilation
resistances and high flow velocities. However, the provision of
rectification portions 8a and 8b in inlet ports 11a, 11b and outlet
ports 12a, 12b allows the opening area of inlet ports 11a, 11b and
the opening area of outlet ports 12a, 12b of flow channels 13a and
13d having a flow channel length longer than the average flow
channel length to be larger than the average opening area. This
decreases the ventilation resistance of flow channels 13a and 13d,
thereby increasing the flow velocity. The provision of
rectification portions 8a and 8b also allows the opening area of
inlet ports 11a, 11b and the opening area of outlet ports 12a, 12b
of flow channels 13b, 13c, 13e, and 13f having flow channel lengths
shorter than the average flow channel length to be made smaller
than the average opening area. This increases the ventilation
resistances of flow channels 13b, 13c, 13e, and 13f, thereby
decreasing the flow velocities. Rectification portions 8a and 8b,
which are formed by bending parts of flow channel division portions
7a and 7b, hardly decrease the effective area of heat exchanger
plates 3a or do not decrease the total opening area of inlet ports
11a, 11b or outlet ports 12a, 12b. This eliminate drift in air
passages 5A and 5B due to different ventilation resistances of flow
channels 13a-13f caused by their different lengths generated by
flow channel division portions 7a and 7b so as to form a
predetermined flow velocity distribution in counterflow regions
14a. This results in providing high heat exchange efficiency.
[0112] Rectification portions 8a and 8b are arranged in inlet ports
11a, 11b and outlet ports 12a, 12b in the present embodiment.
However, these portions 8a and 8b may alternatively be arranged in
either inlet ports 11a and 11b or outlet ports 12a and 12b so as to
obtain the same action and effect by changing the size of the
opening areas.
[0113] As described above, heat exchanger plate 3a is inserted into
an injection mold for molding resin frames 2a and 2b, and molten
resin is injected into the mold and solidified to form resin frames
2a and 2b. Resin frame 2a is joined to heat exchanger plate 3a, and
resin frame 2b is joined to heat exchanger plate 3a. As a result,
resin frames 2a and 2b are integrally molded with heat exchanger
plates 3a. This improves the joint strength between heat exchanger
plate 3a and resin frame 2a having shield portions 6a, flow channel
division portions 7a, and rectification portions 8a, and also
between heat exchanger plate 3a and resin frame 2b having shield
portions 6b, flow channel division portions 7b, and rectification
portions 8b. As a result, this prevents airflow leakage due to
peeling between heat exchanger plate 3a and resin frames 2a,
2b.
[0114] The use of the injection molding process to integrally mold
shield portions 6a, flow channel division portions 7a, and
rectification portions 8a and to integrally mold shield portions
6b, flow channel division portions 7b, rectification portions 8b
provides high-precision spacing between heat exchanger plates 3a in
the thickness direction. This enables heat exchanging element 1a to
maintain its strength, thus preventing bending of heat exchanger
plates 3a, which may be caused if the precision in the thickness
direction is low while unit elements 4a and 4b are alternately
laminated, and also preventing drift in air passages 5A and 5B
which may be caused when unit elements 4a and 4b do not have a
uniform height. This results in providing high heat exchange
efficiency.
[0115] In the present embodiment, specific dimensions are given for
resin frames 2a and 2b, heat exchanger plates 3a, unit elements 4a
and 4b, shield portions 6a and 6b, flow channel division portions
7a and 7b, rectification portions 8a and 8b, engagement projections
9a and 9b, engagement recesses 10a and 10b, inlet ports 11a and
11b, outlet ports 12a and 12b, and flow channels 13a-13f. These
dimensions, however, are not limited to those of the present
embodiment, and can be properly determined depending on the
required performance of heat exchanging element 1a so as to obtain
the action and effect equivalent to those of the present
embodiment.
Second Embodiment
[0116] FIG. 4 is a schematic perspective view of a heat exchanging
element according to a second embodiment of the present invention.
FIG. 5A is a schematic perspective view of one unit element as a
component of the heat exchanging element seen in a direction X of
FIG. 4. FIG. 5B is a schematic perspective view of one unit element
as a component of the heat exchanging element seen in a direction Y
of FIG. 4. Like components are labeled with like reference numerals
with respect to the first embodiment, and these components are not
described again in detail.
[0117] As shown in FIGS. 4, 5A, and 5B, heat exchanging element 1b
according to the second embodiment includes unit elements 4c and
unit elements 4d alternately laminated on each other. Each unit
element 4c includes heat exchanger plate 3b integrally molded with
resin frame 2c. Each unit element 4d includes heat exchanger plate
3b integrally molded with resin frame 2d. Each heat exchanger plate
3b includes air passage 5C on its top surface and air passage 5D on
its bottom surface. Heat exchanging element 1b circulates primary
airflow "A" through air passage 5C, and secondary airflow "B"
through air passage 5D, thereby enabling heat exchange between
primary and secondary airflows "A" and "B" via heat exchanger
plates 3b.
[0118] Unit elements 4c are each formed by integrally molding heat
exchanger plate 3b with resin frame 2c including shield portions
6c, flow channel division portions 7c, rectification portions 8c,
engagement projections 9c, and engagement recesses 10c. Unit
elements 4d are each formed by integrally molding heat exchanger
plate 3b with resin frame 2d including shield portions 6d, flow
channel division portions 7d, rectification portions 8d, engagement
projections 9d, and engagement recesses 10d.
[0119] Unit elements 4c and 4d have a picture plane with a long
side of 145 mm and a short side of 65 mm in the lamination
direction. The alternate lamination of unit elements 4c and unit
elements 4d enables heat exchanging element 1b to have inlet ports
11c and outlet ports 12c of primary airflow "A", and inlet ports
11d and outlet ports 12d of secondary airflow "B". Air passage 5C
is divided into three flow channels 13g, 13h, and 13i by flow
channel division portions 7c. Air passage 5D is divided into three
flow channels 13j, 13k, and 13m by flow channel division portions
7d.
[0120] Shield portions 6c and 6d are arranged on the top and bottom
surfaces, respectively of heat exchanger plate 3b so as to form the
outer frames excluding inlet ports 11c, 11d and outlet ports 12c,
12d. The linear portions of shield portions 6c and 6d have a width
of 4 mm and a height of 0.75 mm. Flow channel division portions 7c
and 7d, which have a width of 1.5 mm and a height of 0.75 mm are
arranged on the top and bottom surfaces, respectively, of heat
exchanger plate 3b so as to fit each other when unit elements 4a
and 4b are laminated.
[0121] Rectification portions 8c are integrally formed with flow
channel division portions 7c in the vicinity of inlet ports 11c,
11d and outlet ports 12c, 12d so as to form projections projecting
into flow channels 13h, 13i, 13k, and 13m. Some of the projections
project 3 mm into flow channels 13h, 13k, and some of the
projections project 5 mm into flow channels 13i, 13m from flow
channel division portions 7c.
[0122] The other projections are formed in counterflow regions 14b
in such a manner as to project 2 mm into flow channels 13i, 13m
from shield portions 6c.
[0123] Rectification portions 8d are integrally formed with flow
channel division portions 7d in the vicinity of inlet ports 11c,
11d and outlet ports 12c, 12d so as to form projections projecting
into flow channels 13h, 13i, 13k, and 13m. Some of the projections
project 3 mm into flow channels 13h, 13k, and some of the
projections project 5 mm into flow channels 13i, 13m from flow
channel division portions 7d.
[0124] The other projections are formed in counterflow regions 14b
in such a manner as to project 2 mm into flow channels 13i, 13m
from shield portions 6d. Rectification portions 8c and 8d fit each
other when unit elements 4c and 4d are alternately laminated.
[0125] Rectification portions 8c and 8d are formed in the following
conditions. The opening area of each of inlet and outlet ports 11c,
12c of flow channel 13g and the opening area of each of inlet and
outlet ports 11d, 12d of flow channel 13j which have a flow channel
length longer than the average flow channel length are made larger
than the average opening area. The opening area of each of inlet
and outlet ports 11c, 12c of flow channels 13h, 13i and the opening
area of each of inlet and outlet ports 11d, 12d of flow channels
13k, 13m which have flow channel lengths shorter than the average
flow channel length are made smaller than the average opening
area.
[0126] The flow channel lengths in the present embodiments are as
follows: flow channels 13g and 13j: 174 mm; flow channels 13h and
13k: 136 mm; and flow channels 13i and 13m: 104 mm. The average
flow channel length is 138 mm. The opening areas in the present
embodiment are as follows: inlet and outlet ports 11c, 12c of flow
channel 13g and inlet and outlet ports 11d, 12d of flow channel
13j: 27 mm.sup.2; inlet and outlet ports 11c, 12c of flow channel
13h and inlet and outlet ports 11d, 12d of flow channel 13k: 16.5
mm.sup.2; and inlet and outlet ports 11c, 12c of flow channel 13i
and inlet and outlet ports 11d, 12d of flow channel 13m: 12
mm.sup.2. The total opening area of inlet ports 11c, 11d and the
total opening area of outlet ports 12c, 12d are both 55.5 mm.sup.2.
The average opening area of inlet ports 11c, 11d and the average
opening area of outlet ports 12c, 12d are both 18.5 mm.sup.2.
[0127] Engagement projections 9c and 9d, which have a width of 1.5
mm and a height of 0.4 mm, are arranged on shield portions 6c and
6d, respectively formed on the top surface of each heat exchanger
plate 3b. Engagement recesses 10c and 10d, which have a width of
1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6c
and 6d, respectively formed on the bottom surface of each heat
exchanger plate 3b. When unit elements 4c and 4d are alternately
laminated, engagement projections 9c and engagement recesses 10d
are engaged with each other, and engagement projections 9d and
engagement recesses 10c are engaged with each other.
[0128] Heat exchanging element 1b is a counter flow type in which
primary and secondary airflows "A" and "B" flow at a right angle or
an oblique angle to each other with heat exchanger plates 3b
therebetween in the vicinity of inlet ports 11c, 11d and outlet
ports 12c, 12d, and flow opposite to each other with heat exchanger
plates 3b therebetween in the center. The regions in which primary
and secondary airflows "A" and "B" flow opposite to each other with
heat exchanger plates 3b therebetween are counterflow regions 14b.
In counterflow regions 14b, flow channels 13g, 13h, 13i, 13j, 13k,
and 13m, which are divided by shield portions 6c, 6d and flow
channel division portions 7c, 7d, have a width of 18 mm.
[0129] Resin frames 2c and 2d are formed of a thermoplastic resin
such as polystyrene (ABS, AS, or PS), or polyolefin (PP or PE).
Heat exchanger plates 3b are cut into a rectangular shape having a
long side of 143 mm and a short side of 63 mm. The thickness is 0.2
to 0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3b
can be made of Japanese paper, flame retardant paper, or
specially-treated paper having heat conductivity, moisture
permeability, and a gas shielding property, or can be a
moisture-permeable film or a resin sheet or film having only heat
conductivity such as polyester, polystyrene (ABS, AS, or PS) or
polyolefin (PP or PE).
[0130] Heat exchanging element 1b according to the present
embodiment has the same production process as heat exchanging
element 1a of the first embodiment, and it is described with
reference to FIG. 3. The production process of heat exchanging
element 1b includes cutting step 15a, molding step 16a, laminating
step 17a, and bonding step 18a performed in this order. Cutting
step 15a cuts heat exchanger plates 3b into shape. Molding step 16a
integrally molds heat exchanger plate 3b with resin frame 2c so as
to form unit element 4c, and also integrally molds heat exchanger
plate 3b with resin frame 2d so as to form unit element 4d.
Laminating step 17a alternately laminates unit elements 4c and unit
elements 4d on each other. Bonding step 18a bonds laminated unit
elements 4c and 4d.
[0131] Cutting step 15a of the present embodiment cuts each heat
exchanger plate 3b into a rectangular shape having a long side of
143 mm and a short side of 63 mm.
[0132] Molding step 16a inserts heat exchanger plate 3b into an
injection mold, injects molten resin into the mold, and solidifies
the molten resin so as to form resin frames 2c and 2d. Resin frame
2c is joined to heat exchanger plate 3b, and resin frame 2d is
joined to heat exchanger plate 3b so as to form unit elements 4c
and 4d.
[0133] Laminating step 17a laminates unit elements 4c and unit
elements 4d alternately on each other so that engagement
projections 9c are engaged with engagement recesses 10d, and
engagement projections 9d are engaged with engagement recesses
10c.
[0134] Bonding step 18a melts the four corners of unit elements 4c
and 4d thus laminated, and parts of the edges of the regions where
inlet ports 11c, 11d or outlet ports 12c, 12d are not formed.
Bonding step 18a then solidifies the molten resin so as to join
unit elements 4c and 4d thus laminated. The resin can be melted by
ultrasonic welding.
[0135] With the above structure, heat exchanging element 1b allows
primary and secondary airflows "A" and "B" to circulate through
their corresponding air passages arranged alternately to prevent
airflows "A" and "B" from being mixed with each other, thereby
enabling heat exchange between primary and secondary airflows "A"
and "B" via heat exchanger plates 3b.
[0136] Besides rectification portions 8c and 8d, like components
are labeled with like reference numerals with respect to the first
embodiment, and these components are not described again in
detail.
[0137] Air passage 5C includes flow channels 13g, 13h, and 13i, and
flow channel 13g has the longest flow channel length. Air passage
5D includes flow channels 13j, 13k, and 13m, and flow channel 13j
has the longest flow channel length. Flow channels 13g and 13j
having the longest flow channel length have a higher ventilation
resistance than the other flow channels 13h, 13i, 13k, and 13m. To
increase the ventilation resistances of flow channels 13h, 13i,
13k, and 13m, flow channel division portions 7c and 7d are provided
with projections as ventilation resistance members projecting into
flow channels 13h, 13i, 13k, and 13m in inlet and outlet ports 11c,
12c of flow channels 13h, 13i and in inlet and outlet ports 11d,
12d of flow channels 13k, 13m. These projections function as
rectification portions 8c and 8d to reduce the opening area of each
of inlet and outlet ports 11c, 12c of flow channels 13h, 13i and
the opening area of each of inlet and outlet ports 11d, 12d of flow
channels 13k, 13m including rectification portions 8c and 8d,
thereby increasing the ventilation resistances. This eliminates
drift in air passages 5C and 5D due to different ventilation
resistances of flow channels 13g, 13h, 13i, 13j, 13k, and 13m
caused by their different flow channel lengths generated by flow
channel division portions 7c and 7d, thereby forming a
predetermined flow velocity distribution in counterflow regions
14b. This results in providing high heat exchange efficiency.
[0138] Furthermore, (not illustrated) arranging some of
rectification portions 8c and 8d as the projections in counterflow
regions 14d eliminates drift in flow channels 13i and 13m and
increases the ventilation resistances of flow channels 13i and 13m.
This eliminates drift in air passages 5C and 5D due to different
ventilation resistances of flow channels 13g, 13h, 13i, 13j, 13k,
and 13m caused by their different flow channel lengths generated by
flow channel division portions 7c and 7d. This results in providing
high heat exchange efficiency.
[0139] Rectification portions 8c and 8d are arranged in inlet ports
11c, 11d, outlet ports 12c, 12d, and counterflow regions 14b in the
present embodiment. However, these portions 8c and 8d may
alternatively be arranged in either inlet ports 11c and 11d or
outlet ports 12c and 12d and counterflow regions 14b, or in either
inlet ports 11c and 11d or outlet ports 12c and 12d so as to obtain
the same action and effect by changing the size of the opening
areas.
[0140] In the present embodiment, specific dimensions are given for
resin frames 2c and 2d, heat exchanger plates 3b, unit elements 4c
and 4d, shield portions 6c and 6d, flow channel division portions
7c and 7d, rectification portions 8c and 8d, engagement projections
9c and 9d, engagement recesses 10c and 10d, inlet ports 11c and
11d, outlet ports 12c and 12d, and flow channels 13g, 13h, 13i,
13j, 13k, and 13m. These dimensions, however, are not limited to
those of the present embodiment, and can be properly determined
depending on the required performance of heat exchanging element 1b
so as to obtain the action and effect equivalent to those of the
present embodiment.
Third Embodiment
[0141] FIG. 6 is a schematic perspective view of a heat exchanging
element according to a third embodiment of the present invention.
FIG. 7 is a schematic perspective view of one unit element as a
component of the heat exchanging element seen in a direction X of
FIG. 6. FIG. 8 is a schematic production flowchart of the heat
exchanging element. Like components are labeled with like reference
numerals with respect to the first and second embodiments, and
these components are not described again in detail.
[0142] As shown in FIGS. 6 and 7, heat exchanging element 1c
includes unit elements 4e and unit elements 4f alternately
laminated on each other. Each unit element 4e includes shield
portions 6e, flow channel division portions 7e, rectification
portions 8e, and spaced projections 19a, which are formed by
providing an uneven surface structure on heat exchanger plate 3c.
Each unit element 4f includes shield portions 6f, flow channel
division portions 7f, rectification portions 8f, and spaced
projections 19b, which are formed by providing an uneven surface
structure on heat exchanger plate 3c. Each heat exchanger plate 3c
includes air passage 5E on its top surface and air passage 5F on
its bottom surface. Heat exchanging element 1c circulates primary
airflow "A" through air passage 5E, and secondary airflow "B"
through air passage 5F, thereby enabling heat exchange between
primary and secondary airflows "A" and "B" via heat exchanger
plates 3c.
[0143] Unit elements 4e and 4f have a picture plane having a long
side of 145 mm and a short side of 65 mm in the lamination
direction after bonded. Unit elements 4e and 4f are formed by
vacuum forming a polystyrene sheet having a thickness of, for
example, 0.2 mm.
[0144] The alternate lamination of unit elements 4e and unit
elements 4f enables heat exchanging element 1c to have inlet ports
11e and outlet ports 12e of primary airflow "A" and inlet ports 11f
and outlet ports 12f of secondary airflow "B". Air passage 5E is
divided into three flow channels 13n, 13p, and 13q by flow channel
division portions 7e. Air passage 5F is divided into three flow
channels 13r, 13s, and 13t.
[0145] Shield portions 6e and 6f are arranged to form the outer
frames excluding inlet ports 11e, 11f and outlet port 12e, 12f. The
linear portions of shield portions 6e and 6f have a width of 4 mm
and a height of 1.5 mm from heat exchanger plate 3c.
[0146] Flow channel division portions 7e and 7f are arranged to
have a width of 1.5 mm and a height of 1.5 mm from heat exchanger
plate 3c.
[0147] Rectification portions 8e are integrally formed with flow
channel division portions 7e by bending flow channel division
portions 7e in the vicinity of inlet and outlet ports 11e, 12e so
as to have a width of 1.5 mm and a height of 1.5 mm from heat
exchanger plate 3c. Rectification portions 8f are integrally formed
with flow channel division portions 7f by bending flow channel
division portions 7f in the vicinity of inlet and outlet ports 11f,
12f so as to have a width of 1.5 mm and a height of 1.5 mm from
heat exchanger plate 3c.
[0148] Rectification portions 8e and 8f are formed by bending flow
channel division portions 7e and 7f in the following conditions.
The opening area of each of inlet and outlet ports 11e, 12e of flow
channel 13n and the opening area of each of inlet and outlet ports
11f, 12f of flow channel 13r which have a flow channel length
longer than the average flow channel length are made larger than
the average opening area. The opening area of each of inlet and
outlet ports 11e, 12e of flow channels 13p, 13q and the opening
area of each of inlet and outlet ports 11f, 12f of flow channels
13s, 13t which have flow channel lengths shorter than the average
flow channel length are made smaller than the average opening
area.
[0149] The flow channel lengths in the present embodiment are as
follows: flow channels 13n and 13r: 182 mm; flow channels 13p and
13s: 142 mm; and flow channels 13q and 13t: 105 mm. The average
flow channel length is 143 mm. The opening areas in the present
invention are as follows: inlet ports 11e and 11f respectively of
flow channels 13n and 13r: 39 mm.sup.2; outlet ports 12e and 12f
respectively of flow channels 13n and 13r: 34.5 mm.sup.2; inlet
ports 11e and 11f respectively of flow channels 13p and 13s: 22.5
mm.sup.2; outlet ports 12e and 12f respectively of flow channel 13p
and 13s: 24 mm.sup.2; inlet ports 11e and 11f respectively of flow
channels 13q and 13t: 15 mm.sup.2, and outlet ports 12e and 12f
respectively of flow channels 13q and 13t: 18 mm.sup.2. The total
opening area of inlet ports 11e, 11f and the total opening area of
outlet ports 12e, 12f are both 76.5 mm.sup.2. The average opening
area of inlet ports 11e, 11f and the average opening area of outlet
port 12e, 12f are both 25.5 mm.sup.2.
[0150] Spaced projections 19a, 19b, which are arranged on shield
portions 6e, 6f, flow channel division portions 7e, 7f, and
rectification portions 8e, 8f, respectively, play a role in
maintaining the spacing between heat exchanger plates 3c when unit
elements 4e and 4f are alternately laminated.
[0151] Heat exchanging element 1c is a counter flow type in which
primary and secondary airflows "A" and "B" flow at a right angle or
an oblique angle to each other with heat exchanger plates 3c
therebetween in the vicinity of inlet ports 11e, 11f and outlet
ports 12e, 12f, and flow opposite to each other with heat exchanger
plates 3c therebetween in the center. The regions in which primary
and secondary airflows "A" and "B" flow opposite to each other with
heat exchanger plates 3c therebetween are referred to as
counterflow regions 14c. In counterflow regions 14c, flow channels
13n, 13p, 13q, 13r, 13s, and 13t have a width of 18 mm.
[0152] Heat exchanger plates 3c are formed of resin sheets or films
of polyester, polystyrene (ABS, AS, or PS), or polyolefin (PP or
PE). The thickness is preferably 0.2 to 0.1 mm, and is 0.2 mm in
the present embodiment.
[0153] As shown in FIG. 8, the production process of heat
exchanging element 1c includes cutting step 15b, molding step 16b,
laminating step 17b, and bonding step 18b performed in this order.
Cutting step 15b cuts heat exchanger plates 3c into shape. Molding
step 16b forms an uneven surface structure on heat exchanger plates
3c by a forming method such as vacuum forming, and then cuts
unnecessary parts off so as to form unit elements 4e and 4f.
Laminating step 17b alternately laminates unit elements 4e and unit
elements 4f on each other. Bonding step 18b bonds unit elements 4e
and 4f thus laminated.
[0154] Molding step 16b forms the uneven surface structure by
processing heat exchanger plate 3c of a polystyrene sheet or the
like by vacuum forming, and cuts off parts unnecessary to form heat
exchanging element 1c so as to form unit elements 4e and 4f.
Besides vacuum forming, heat exchanger plate 3c may be formed by
air-pressure forming, pressing or the like.
[0155] Bonding step 18b melts the edges of laminated unit elements
4e and 4f, and solidifies the molten resin so as to join unit
elements 4e and 4f thus laminated.
[0156] With the above structure, heat exchanging element 1c allows
primary and secondary airflows "A" and "B" to circulate through
their corresponding air passages arranged alternately to prevent
airflows "A" and "B" from being mixed with each other, thereby
enabling heat exchange between primary and secondary airflows "A"
and "B" via heat exchanger plates 3c.
[0157] Like components are labeled with like reference numerals
with respect to the first embodiment, and these components are not
described again in detail.
[0158] Unit elements 4e and 4f are formed by providing the uneven
surface structure on heat exchanger plates 3c, which are formed of
a thermoplastic resin such as polystyrene by vacuum forming or the
like. Heat exchanger plates 3c, shield portions 6e, 6f, flow
channel division portions 7e, 7f, rectification portions 8e, 8f,
and spaced projections 19a, 19b are all made of the same material.
This prevents peeling between heat exchanger plates 3c and other
components, and hence, airflow leakage due to peeling. The integral
molding of shield portions 6e, flow channel division portions 7e,
rectification portions 8e, and spaced projections 19a; and the
integral molding of shield portions 6f, flow channel division
portions 7f, rectification portions 8f, and spaced projections 19b
provide high-precision spacing between heat exchanger plates 3c in
the thickness direction when unit elements 4e and 4f are laminated
on each other. This enables the heat exchanging element to maintain
its strength, thus preventing bending of heat exchanger plates 3c,
which may be caused if the precision in the thickness direction is
low while unit elements 4e and 4f are alternately laminated, and
also preventing drift in air passages 5E and 5F which may be caused
when unit elements 4e and 4f do not have a uniform height. This
results in providing high heat exchange efficiency.
[0159] In the present embodiment, specific dimensions are given for
heat exchanger plates 3c, unit elements 4e and 4f, shield portions
6e and 6f, flow channel division portions 7e and 7f, rectification
portions 8e and 8f, inlet ports 11e and 11f, outlet ports 12e and
12f, flow channels 13n, 13p, 13q, 13r, 13s, and 13t, and spaced
projections 19a and 19b. These dimensions, however, are not limited
to those of the present embodiment, and can be properly determined
depending on the required performance of heat exchanging element 1c
so as to obtain the action and effect equivalent to those of the
present embodiment.
Fourth Embodiment
[0160] FIG. 9 is a schematic perspective view of a heat exchanging
element according to a fourth embodiment of the present invention.
FIG. 10A is a schematic perspective view of one unit element as a
component of the heat exchanging element seen in a direction X of
FIG. 9. FIG. 10B is an enlarged schematic perspective view of one
unit element as a component of the heat exchanging element seen in
the direction X of FIG. 9. FIG. 10C is an enlarged schematic
perspective view of the unit element taken along line A-A of FIG.
10B. FIG. 11 is a schematic perspective view of one unit element as
a component of the heat exchanging element seen in a direction Y of
FIG. 9. Like components are labeled with like reference numerals
with respect to the first to third embodiments, and these
components are not described again in detail.
[0161] As shown in FIGS. 9, 10A, 10B, 10C, and 11, heat exchanging
element 1d includes unit elements 4g and unit elements 4h
alternately laminated on each other. Each unit element 4g includes
heat exchanger plate 3d integrally molded with resin frame 2e. Each
unit element 4h includes heat exchanger plate 3d integrally molded
with resin frame 2f. Each heat exchanger plate 3d includes air
passage 5G on its top surface and air passage 5H on its bottom
surface. Heat exchanging element 1d circulates primary airflow "A"
through air passage 5G, and secondary airflow "B" through air
passage 5H, thereby enabling heat exchange between primary and
secondary airflows "A" and "B" via heat exchanger plates 3d.
[0162] Unit elements 4g are each formed by integrally molding heat
exchanger plate 3d with resin frame 2e including shield portions
6g, flow channel division portions 7g, rectification portions 8g,
engagement projections 9e, and engagement recesses 10e. Unit
elements 4h are each formed by integrally molding heat exchanger
plate 3d with resin frame 2f including shield portions 6h, flow
channel division portions 7h, rectification portions 8h, engagement
projections 9f, and engagement recesses 10f. Unit elements 4g and
4h have a picture plane having a long side of 145 mm and a short
side of 65 mm in the lamination direction.
[0163] The alternate lamination of unit elements 4g and unit
elements 4h enables heat exchanging element 1d to have inlet ports
11g and outlet ports 12g of primary airflow "A" and inlet ports 11h
and outlet ports 12h of secondary airflow "B". Air passage 5G is
divided into three flow channels 13u, 13v, and 13w by flow channel
division portions 7g. Air passage 5H is divided into three flow
channels 13x, 13y, and 13z by flow channel division portions
7h.
[0164] Shield portions 6g and 6h are arranged on the top and bottom
surfaces, respectively, of heat exchanger plate 3d so as to form
the outer frames excluding inlet ports 11g, 11h and outlet ports
12g, 12h. The linear portions of shield portions 6g and 6h have a
width of 4 mm and a height of 0.75 mm.
[0165] Flow channel division portions 7g and 7h, which have a width
of 1.5 mm and a height of 0.75 mm, are arranged on the top and
bottom surfaces, respectively, of heat exchanger plate 3d so as to
fit each other when unit elements 4g and 4h are laminated.
Rectification portions 8g include portions that are integrated with
shield portions 6g in the vicinity of inlet ports 11g, 11h and
outlet ports 12g, 12h, and portions that are formed between one
side surface of heat exchanger plate 3d and the reverse side of
flow channel division portions 7g.
[0166] Of rectification portions 8g, the portions that are
integrated with shield portions 6g in the vicinity of inlet ports
11g, 11h and outlet ports 12g, 12h form projections projecting into
flow channels 13v, 13w, 13y, and 13z. The projections projecting
into flow channels 13v and 13y are inclined with respect to shield
portions 6g by 0.3 mm on the opening side and by 0 mm on the inner
side. The projections projecting into flow channels 13w and 13z are
inclined with respect to shield portions 6g by 0.15 mm on the
opening side and by 0 mm on the inner side.
[0167] Of rectification portions 8g, the portions that are formed
between the flow-channel (13v, 13w, 13y, or 13z) side surface of
heat exchanger plate 3d and the reverse side of flow channel
division portions 7g form projections projecting 0.15 mm. The
"opening side" indicates the side of inlet port 11g or 11h or the
side of outlet ports 12g or 12h as seen from inside heat exchanging
element 1d. The "inner side" indicates inside heat exchanging
element 1d as seen from inlet port 11g or 11h or outlet ports 12g
and 12h.
[0168] Rectification portions 8h include portions that are
integrated with shield portions 6h in the vicinity of inlet ports
11g, 11h and outlet ports 12g, 12h, and portions that are formed
between one side surface of heat exchanger plate 3d and the reverse
side of flow channel division portions 7h. Of rectification
portions 8h, the portions that are integrated with shield portions
6h in the vicinity of inlet ports 11g, 11h and outlet ports 12g,
12h form projections projecting into flow channels 13v, 13w, 13y,
and 13z. The projections projecting into flow channels 13v and 13y
are inclined with respect to shield portions 6h by 0.3 mm on the
opening side and by 0 mm on the inner side. The projections
projecting into flow channels 13w and 13z are inclined with respect
to shield portions 6h by 0.15 mm on the opening side and by 0 mm on
the inner side. Of rectification portions 8h, the portions that are
formed between the flow-channel (13v, 13w, 13y, or 13z) side
surface of heat exchanger plate 3d and the reverse side of flow
channel division portions 7h form projections projecting 0.15
mm.
[0169] Rectification portions 8g and 8h are formed in the following
conditions. The opening area of each of inlet and outlet ports 11g,
12g of flow channels 13v, 13w and the opening area of each of inlet
and outlet ports 11h, 12h of flow channels 13y, 13z are made
smaller than the opening area of each of inlet and outlet ports
11g, 12g of flow channel 13u and the opening area of each of inlet
and outlet ports 11h, 12h of flow channel 13x which have the
longest flow channel length. The flow channel lengths in the
present embodiment are as follows: flow channels 13u and 13x: 180
mm; flow channels 13v and 13y: 140 mm; and flow channels 13w and
13z: 104 mm. The average flow channel length is 141.3 mm. The
opening areas in the present embodiment are as follows: inlet and
outlet ports 11g, 12g of flow channel 13u and inlet and outlet
ports 11h, 12h of flow channel 13x: 27 mm.sup.2; inlet and outlet
ports 11g, 12g of flow channel 13v and inlet and outlet ports 11h,
12h of flow channel 13y: 21.6 mm.sup.2; and inlet and outlet ports
11g, 12g of flow channel 13w and inlet and outlet ports 11h, 12h of
flow channel 13z: 16.2 mm.sup.2.
[0170] Engagement projections 9e and 9f, which have a width of 1.5
mm and a height of 0.4 mm, are arranged on shield portions 6g and
6h, respectively formed on the top surface of each heat exchanger
plate 3d. Engagement recesses 10e and 10f, which have a width of
1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6g
and 6h, respectively formed on the bottom surface of each heat
exchanger plate 3d. When unit elements 4g and 4h are alternately
laminated, engagement projections 9e and engagement recesses 10f
are engaged with each other, and engagement projections 9f and
engagement recesses 10e are engaged with each other.
[0171] Heat exchanging element 1d is a counter flow type in which
primary and secondary airflows "A" and "B" flow at a right angle or
an oblique angle to each other with heat exchanger plates 3d
therebetween in the vicinity of inlet ports 11g, 11h and outlet
ports 12g, 12h, and flow opposite to each other with heat exchanger
plates 3d therebetween in the center. The regions in which primary
and secondary airflows "A" and "B" flow opposite to each other with
heat exchanger plates 3d therebetween are referred to as
counterflow regions 14d. In counterflow regions 14d, flow channels
13u, 13v, 13w, 13x, 13y, and 13z, which are divided by shield
portions 6g, 6h and flow channel division portions 7g, 7h, have a
width of 18 mm.
[0172] Resin frames 2e and 2f are formed of a thermoplastic resin
such as polystyrene (ABS, AS, or PS) or polyolefin (PP or PE). Heat
exchanger plates 3d are cut into a rectangular shape having a long
side of 143 mm and a short side of 63 mm. The thickness is 0.2 to
0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3d
can be made of Japanese paper, flame retardant paper, or
specially-treated paper having heat conductivity, moisture
permeability, and a gas shielding property, or can be a
moisture-permeable film or a resin sheet or film having only heat
conductivity such as polyester, polystyrene (ABS, AS, or PS), or
polyolefin (PP or PE).
[0173] Heat exchanging element 1d according to the present
embodiment has the same production process as heat exchanging
element 1a of the first embodiment, and it is described with
reference to FIG. 3. The production process of heat exchanging
element 1d includes cutting step 15a, molding step 16a, laminating
step 17a, and bonding step 18a performed in this order. Cutting
step 15a cuts heat exchanger plates 3d into shape. Molding step 16a
integrally molds heat exchanger plate 3d with resin frame 2e so as
to form unit element 4g, and also integrally molds heat exchanger
plate 3d with resin frame 2f so as to form unit element 4h.
Laminating step 17a alternately laminates unit elements 4g and unit
elements 4h on each other. Bonding step 18a bonds laminated unit
elements 4g and 4h.
[0174] Cutting step 15a of the present embodiment cuts each heat
exchanger plate 3d into a rectangular shape having a long side of
143 mm and a short side of 63 mm.
[0175] Molding step 16a inserts heat exchanger plate 3d into an
injection mold, injects molten resin into the mold, and solidifies
the molten resin so as to form resin frames 2e and 2f. Resin frame
2e is joined to heat exchanger plate 3d, and resin frame 2f is
joined to heat exchanger plate 3d so as to form unit elements 4g
and 4h.
[0176] Laminating step 17a laminates unit elements 4g and unit
elements 4h alternately on each other so that engagement
projections 9e are engaged with engagement recesses 10f, and
engagement projections 9f are engaged with engagement recesses
10e.
[0177] Bonding step 18a melts the four corners of unit elements 4g
and 4h thus laminated, and parts of the edges of the regions where
inlet ports 11g, 11h or outlet ports 12g, 12h are not formed.
Bonding step 18a then solidifies the molten resin so as to join
unit elements 4g and 4h thus laminated. The resin can be melted by
ultrasonic welding.
[0178] With the above structure, heat exchanging element 1d allows
primary and secondary airflows "A" and "B" to circulate through
their corresponding air passages arranged alternately to prevent
airflows "A" and "B" from being mixed with each other, thereby
enabling heat exchange between primary and secondary airflows "A"
and "B" via heat exchanger plates 3d.
[0179] Besides rectification portions 8g and 8h, like components
are labeled with like reference numerals with respect to the first
embodiment, and these components are not described again in
detail.
[0180] Air passage 5G includes flow channels 13u, 13v, and 13w, and
flow channel 13u has the longest flow channel length. Air passage
5H includes flow channels 13x, 13y, and 13z, and flow channel 13x
has the longest flow channel length. If rectification portions 8g
and 8h are not provided, flow channels 13u and 13x having the
longest flow channel length have a higher ventilation resistance
than the other flow channels 13v, 13w, 13y, and 13z. To increase
the ventilation resistances of flow channels 13v, 13w, 13y, and
13z, shield portions 6g and 6h are provided with projections as
ventilation resistance members projecting into flow channels 13v,
13w, 13y, and 13z in inlet and outlet ports 11g, 12g of flow
channels 13v, 13w and in inlet and outlet ports 11h, 12h of flow
channels 13y, 13z. These projections function as rectification
portions 8g and 8h to reduce the opening area of each of inlet and
outlet ports 11g, 12g of flow channels 13v, 13w and the opening
area of each of inlet and outlet ports 11h, 12h of flow channels
13y, 13z including rectification portions 8g and 8h, thereby
increasing the ventilation resistances.
[0181] This eliminates drift in air passages 5G and 5H due to
different ventilation resistances of flow channels 13u, 13v, 13w,
13x, 13y, and 13z caused by their different flow channel lengths
generated by flow channel division portions 7g and 7h, thereby
forming a predetermined flow velocity distribution in counterflow
regions 14d. This results in providing high heat exchange
efficiency. As described above, the portions that are formed
between the flow-channel (13v, 13w, 13y, or 13z) side surface of
heat exchanger plate 3d and the reverse side of flow channel
division portions 7g, 7h form projections as ventilation resistance
members, which function as rectification portions 8g, 8h. This
increases the ventilation resistances of flow channels 13v, 13w,
13y, and 13z including rectification portions 8g and 8h. As a
result, this eliminates drift in air passages 5G and 5H due to
different ventilation resistances of flow channels 13u, 13v, 13w,
13x, 13y, and 13z caused by their different flow channel lengths
generated by flow channel division portions 7g and 7h, thereby
forming a predetermined flow velocity distribution in counterflow
regions 14d. This results in providing high heat exchange
efficiency. Rectification portions 8g and 8h are arranged in inlet
ports 11g and 11h, outlet ports 12g and 12h, and in some portions
between one side surface of heat exchanger plate 3d and the reverse
side of flow channel division portions 7g or 7h in the present
embodiment. However, these portions 8g and 8h may alternatively be
arranged in either inlet ports 11g and 11h or outlet ports 12g and
12h, and in some portions between one side surface of heat
exchanger plate 3d and the reverse side of flow channel division
portions 7g or 7h; only in inlet ports 11g, 11h and outlet port
12g, 12h; or only in some portions between one side surface of heat
exchanger plate 3d and the reverse side of flow channel division
portions 7g or 7h. In all of these cases, the same action and
effect can be obtained by changing the size of the opening
areas.
[0182] In the present embodiment, specific dimensions are given for
resin frames 2e and 2f, heat exchanger plates 3d, unit elements 4g
and 4h, shield portions 6g and 6h, flow channel division portions
7g and 7h, rectification portions 8g and 8h, engagement projections
9e and 9f, engagement recesses 10e and 10f, inlet ports 11g and
11h, outlet ports 12g and 12h, and flow channels 13u, 13v, 13w,
13x, 13y, and 13z. These dimensions, however, are not limited to
those of the present embodiment, and can be properly determined
depending on the required performance of heat exchanging element 1d
so as to obtain the action and effect equivalent to those of the
present embodiment.
INDUSTRIAL APPLICABILITY
[0183] The lamination type heat exchanging element of the present
invention, which is for use in heat exchange type ventilation fans
for domestic use, in heat exchange type ventilators for buildings
or other structures, and in other air conditioning devices,
provides high industrial applicability.
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