U.S. patent application number 09/921926 was filed with the patent office on 2002-05-02 for heat exchanger for air compressor.
Invention is credited to Hattori, Toshio, Miura, Haruo, Naruse, Tomohiro, Takahashi, Kazuki, Taniyama, Minoru, Tsuru, Seiji.
Application Number | 20020050345 09/921926 |
Document ID | / |
Family ID | 18812668 |
Filed Date | 2002-05-02 |
United States Patent
Application |
20020050345 |
Kind Code |
A1 |
Miura, Haruo ; et
al. |
May 2, 2002 |
Heat exchanger for air compressor
Abstract
A heat exchanger used in a screw air compressor has a low
temperature chamber through which low temperature fluid flows and a
high temperature chamber through which high temperature fluid
flows. The low temperature chamber and the high temperature chamber
are separated by a partition plate. The high temperature chambers
and the low temperature chambers are alternately arranged in
layers, so that the low temperature chambers are disposed at both
ends in a layered direction. Additionally, the flowing direction of
the low temperature fluid in the low temperature chambers and the
flowing direction of the high temperature fluid in the high
temperature chambers are substantially orthogonal to each
other.
Inventors: |
Miura, Haruo; (Chiyoda,
JP) ; Takahashi, Kazuki; (Tsuchiura, JP) ;
Tsuru, Seiji; (Tsuchiura, JP) ; Taniyama, Minoru;
(Ami, JP) ; Naruse, Tomohiro; (Chiyoda, JP)
; Hattori, Toshio; (Ushiku, JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
18812668 |
Appl. No.: |
09/921926 |
Filed: |
August 6, 2001 |
Current U.S.
Class: |
165/166 ;
165/164 |
Current CPC
Class: |
F28F 2250/102 20130101;
F28F 9/00 20130101; F28D 9/0062 20130101; F28F 3/025 20130101 |
Class at
Publication: |
165/166 ;
165/164 |
International
Class: |
F28D 007/02; F28F
003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2000 |
JP |
2000-337253 |
Claims
What is claimed is:
1. A heat exchanger for an air compressor, comprising a heat
exchanger nest having a plurality of low temperature chambers
through which low temperature fluid flows and a plurality of high
temperature chambers through which high temperature fluid flows,
the low temperature chambers and the high temperature chambers
being alternately arranged in layers through a partition plate
interposed therebetween, wherein a flowing direction of the low
temperature fluid in the low temperature chambers and a flowing
direction of the high temperature fluid in the high temperature
chambers are substantially orthogonal to each other, and the both
ends of the layered heat exchanger nest are the low temperature
chambers.
2. A heat exchanger for an air compressor, comprising a heat
exchanger nest formed by alternately arranging a plurality of low
temperature chambers through which low temperature fluid flows and
a plurality of high temperature chambers through which high
temperature fluid flows in layers through a partition plate
interposed therebetween, wherein the number of the high temperature
chambers is smaller than that of the low temperature chambers by
one, and a flowing direction of the low temperature fluid in the
low temperature chambers and a flowing direction of the high
temperature fluid in the high temperature chambers are
substantially orthogonal to each other.
3. A heat exchanger according to claim 1, wherein the low
temperature fluid is cooling water and the high temperature fluid
is compressed air.
4. A screw compressor provided with a heat exchanger according to
claim 1.
5. A screw compressor provided with a heat exchanger according to
claim 2.
6. A heat exchanger according to claim 1, further comprising a
container for accommodating the heat exchanger nest, wherein the
container is provided with a container side projecting seal formed
on an inner surface of a side thereof, and the heat exchanger nest
is also provided with a nest side projecting seal formed on a side
thereof, and wherein the container side seal and the nest side seal
are coupled through a seal member which can be elastically deformed
in contact with both seals, so as to form a seal part for
partitioning the inside of the container into several portions.
7. A heat exchanger according to claim 2, further comprising a
container for accommodating the heat exchanger nest, wherein the
container is provided with a container side projecting seal formed
on an inner surface of a side thereof, and the heat exchanger nest
is also provided with a nest side projecting seal formed on a side
thereof, and wherein the container side seal and the nest side seal
are coupled through a seal member which can be elastically deformed
in contact with both seals, so as to form a seal part for
partitioning the inside of the container into several portions.
8. A heat exchanger according to claim 6, wherein the nest side
seal is provided in the vicinity of an outlet of the low
temperature fluid.
9. A heat exchanger according to claim 7, wherein the nest side
seal is provided in the vicinity of an outlet of the low
temperature fluid.
10. A heat exchanger according to claim 6, wherein the nest side
seal is provided so as to project from a bottom surface of the heat
exchanger nest, so that compressive load is loaded on the seal
member due to the mass of the heat exchanger nest.
11. A heat exchanger according to claim 7, wherein the nest side
seal is provided so as to project from a bottom surface of the heat
exchanger nest, so that compressive load is loaded on the seal
member due to the mass of the heat exchanger nest.
12. A heat exchanger according to claim 6, wherein the cross
sectional area of the seal member is larger than those of
contacting parts between the seal member and the container side
seal, and the seal member and the nest side seal.
13. A heat exchanger according to claim 7, wherein the cross
sectional area of the seal member is larger than those of
contacting parts between the seal member the container side seal
and, the seal member and the nest side seal.
14. A heat exchanger according to claim 6, wherein the seal member
includes at least one of ethylene-propylene rubber, acrylic rubber,
silicone rubber, and fluoro-rubber, as a principal component.
15. A heat exchanger according to claim 7, wherein the seal member
includes at least one of ethylene-propylene rubber, acrylic rubber,
silicone rubber, and fluoro-rubber, as a principal component.
16. A heat exchanger according to claim 6, wherein the seal member
is a gas tube seal which is constituted by forming a polymeric
material into a tube, and sealing or injecting gas therein.
17. A heat exchanger according to claim 7, wherein the seal member
is a gas tube seal which is constituted by forming a polymeric
material into a tube, and sealing or injecting gas therein.
18. A heat exchanger according to claim 6, further comprising a
clamp for pressing the heat exchanger nest to the container side
seal.
19. A heat exchanger according to claim 7, further comprising a
clamp for pressing the heat exchanger nest to the container side
seal.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a medium or small capacity
air compressor which is used as a power air source or the like for
factories, and more particularly to a heat exchanger provided in
those air compressors.
[0002] A screw-type compressor and a compact turbo compressor are
known as a medium or small capacity air compressor whose discharge
pressure is approximately 0.7 MPa in gauge pressure and whose
output power is in a class from less than 100 kW to several
hundreds kW, and are used as a power air source for factories. An
example of such an air compressor is disclosed in JP-A-8-105386 or
JP-A-2000-120585. In these specifications, a laminated type of heat
exchanger or a fin tube type of heat exchanger is used for cooling
compressed air generated by the medium or small capacity turbo
compressor.
[0003] In JP-A-8-105386, a gas cooler for cooling the compressed
gas is inserted with a predetermined gap into a cooler shell
through which the compressed gas flows while a seal part is formed
on an outer circumferential part of the gas cooler for sealing the
gap to divide the inside of the cooler shell into a high
temperature side and a low temperature side, so that the seal part
of the gas cooler has rigidity and sealability. The seal part
projects from the outer circumferential part of the gas cooler, and
is elastically contacted with an inner wall of the cooler shell.
Further, JP-A-2000-120585 discloses a pressure container provided
with a pair of rails having a recess part at one end thereof, in
which a nest accommodated in the pressure container is provided
with a roller to be fitted into the recess part after traveling on
the rail, so that reliability and maintenance efficiency of the
seal are improved.
[0004] The sealing ability is improved by way of each sealing
method described in the above prior art, however, it becomes
complicated to process the seal part because of its complicated
structure. In addition, the assembling is troublesome because the
elastic seal becomes resistant when the nest is inserted into a
casing. Further, it is also difficult to completely prevent
leakage.
BRIEF SUMMARY OF THE INVENTION
[0005] In view of disadvantages of the above prior art, an object
of the present invention is to prevent the heat exchange efficiency
from decreasing due to the leakage between a cooling apparatus nest
and a casing, by a simple structure. Another object of the present
invention is to provide a high performance heat exchanger capable
of cooling high temperature fluid. The present invention achieves
at least one of these objects.
[0006] In order to achieve the above-described object, according to
one aspect of the present-invention, there is provided a heat
exchanger for an air compressor, comprising a heat exchanger nest
having a plurality of low temperature chambers through which low
temperature fluid flows and a plurality of high temperature
chambers through which high temperature fluid flows, the low
temperature chambers and the high temperature chambers being
alternately arranged in layers through a partition plate interposed
therebetween, wherein a flowing direction of the low temperature
fluid in the low temperature chambers and a flowing direction of
the high temperature fluid in the high temperature chambers are
substantially orthogonal to each other, and the both ends of the
layered heat exchanger nest are the low temperature chambers.
[0007] According to another aspect of the present invention, there
is provided a heat exchanger for an air compressor, comprising a
heat exchanger nest formed by alternately arranging a plurality of
low temperature chambers through which low temperature fluid flows
and a plurality of high temperature chambers through which high
temperature fluid flows in layers through a partition plate
interposed therebetween, wherein the number of the high temperature
chambers is smaller than that of the low temperature chambers by
one, and a flowing direction of the low temperature fluid in the
low temperature chambers and a flowing direction of the high
temperature fluid in the high temperature chambers are
substantially orthogonal to each other.
[0008] In these respect, features, it is desirable that the low
temperature fluid is cooling water and the high temperature fluid
is compressed air. Further, the hear exchanger for an air
compressor having these features may be provided in a screw
compressor.
[0009] In the above-described aspects, it is desirable that the
heat exchanger further comprises a container for accommodating the
heat exchanger nest, in which the container is provided with a
container side projecting seal formed on an inner surface of a side
thereof, and the heat exchanger nest is also provided with a nest
side projecting seal formed on a side thereof, wherein the
container side seal and the nest side seal are coupled through a
seal member which can be elastically deformed in contact with both
seals, so as to form a seal part for partitioning the inside of the
container into several portions.
[0010] Preferably, the nest side seal may be provided in the
vicinity of an outlet of the low temperature fluid; the nest side
seal may be provided so as to project from a bottom surface of the
heat exchanger nest, so that compressive load is loaded on the seal
member due to the mass of the heat exchanger nest; the cross
sectional area of the seal member may be larger than those of
contacting parts between the seal member and the container side
seal, and the seal member and the nest side seal; the seal member
may include at least one of ethylene-propylene rubber, acrylic
rubber, silicone rubber, and fluoro-rubber, as a principal
component; the seal member may be a gas tube seal which is
constituted by forming a polymeric material into a tube, and
sealing or injecting gas therein; and a clamp may be provided for
pressing the heat exchanger nest to the container side seal.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0011] FIGS. 1-4 are a front view, a plane view, and a side view of
an embodiment of a screw compressor having a heat exchanger
according to the present invention, and a cross sectional view of a
casing of the screw compressor, respectively;
[0012] FIG. 5 is another cross sectional view of the casing shown
in FIG. 4;
[0013] FIG. 6 is a plane view of one embodiment of a heat exchanger
according to the present invention, and
[0014] FIG. 7 is a side view thereof;
[0015] FIGS. 8 and 9 are cross sectional views of another
embodiment of the heat exchanger according to the present
invention, and FIG. 10 is a front view of the heat exchanger shown
in FIG. 9;
[0016] FIG. 11 is a three-side view of another embodiment of a seal
member according to the present invention;
[0017] FIGS. 12A, 12B, and 13 are cross sectional views of
variations of a seal member according to the present invention;
[0018] FIG. 14 is a view for explaining flow of air which flows in
the heat exchanger according to the present invention;
[0019] FIG. 15 is a view for explaining details of water chambers
and gas chambers according to the present invention;
[0020] FIGS. 16-19 are a plane view, a side view, and an A-A cross
sectional view of the heat exchanger used in a preliminary test,
and a view for explaining a state where an outer gas chamber is
closed using the A-A cross sectional view, respectively; and
[0021] FIG. 20 is a view for explaining cooling performance in the
preliminary test.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Now, some embodiments of the present invention will be
described referring to the drawings. At first, findings based on
preliminary tests related to the present invention will be
described. In a heat exchanger according to the present invention,
there are formed flow passages which are separated by a partition
plate and orthogonal to each other, through which two different
kinds of working fluids flow respectively. When the working fluids
flow through the orthogonal flow passages respectively, the heat is
transferred from a high temperature chamber on a high temperature
side to a low temperature chamber on a low temperature side through
the partition plate. This allows the fluid on the high temperature
side to be cooled. The high temperature chamber and the low
temperature chamber make a pair, and a plurality of pairs are
stacked in multiple layers to form a heat exchanger, referred to as
a nest. Examples of such heat exchangers are described in Heat
Transfer Engineering Data Book (forth Edition), published by the
Japan Society of Mechanical Engineers, p. 261. According to this
publication, this type of heat exchanger is classified as a compact
heat exchanger. In the compact heat exchanger, since a heat
transfer coefficient on the high temperature chamber side is small
when using cooling water as a fluid for the low temperature chamber
and using compressed air as a fluid for the high temperature
chamber, a corrugated fin is employed or a slit referred to as a
louver is provided in the corrugated fins to increase heat transfer
area and to improve the heat transfer coefficient. In view of this
advantage regarding the miniaturization, it is readily thought of
to apply the compact heat exchanger to a compressor. However, since
the difference between the heat transfer coefficients is large in
the heat exchanger for the air compressor as described above, it is
not possible to achieve sufficient performance by simply applying
the compact heat exchanger to the air compressor. Thus, according
to the present invention, there is used a nest in which the number
of high temperature chambers is larger than that of low temperature
chambers as described below in detail, in consideration of the
property of a compact heat exchanger and the economy.
[0023] A nest having five lines of high temperature chambers and
four lines of low temperature chambers was fabricated so as to make
the number of the high temperature chambers larger than that of the
low temperature chambers, and then its cooling ability was
measured, however, desired cooling ability (heat passing
coefficient) can not be obtained. Then, temperature distribution of
the fluid in the high temperature chambers (hereinafter, referred
to as gas chambers) disposed at both ends, and gas outlet
temperature of the gas chambers disposed between the low
temperature chambers (hereinafter, referred to as water chambers)
at the middle of the nest were measured. The result will be
described referring to FIGS. 16 to 20. FIGS. 16 and 17 are a plane
view and a side view of a corrugated fin type heat exchanger nest
designed as a cooler for an air compressor, respectively.
[0024] The total number of the gas chambers 51 is five, and that of
the water chambers 52 is four, so that the gas chambers 51 is
disposed at both ends. The heat passing amounts on a water side and
a air side are balanced by increasing the heat transfer area on the
air side of which the thermal conductivity is lower than that of
water. A gas flow direction 58 in FIG. 17 is from top to bottom,
while the cooling water 59 enters from a lower part of a front side
tube plate 53, and changes its direction at a rear side water
chamber case 54 to exit from an upper part of the front side tube
plate 53. Accordingly, the two kinds of working fluids are
separated by the partition plate 55 and orthogonal to each other.
Heat is transferred from the high temperature side to the low
temperature side through the partition plate 55. The high
temperature fluid flows from top to bottom, while the cooling water
enters from the lower part of the front side tube plate 53 so as to
be orthogonal to the flow of the high temperature fluid, then
changes its direction at the rear side water chamber case 54, and
flows out from the upper part of the front side tube plate.
Corrugated fins are provided in the gas chamber so as to increase
the heat transfer area by the fins. The heat transfer area is
increased by the fins, so that the lower thermal conductivity as
compared with water is compensated.
[0025] Although not shown, a heat exchanger for an air compressor
is formed by enclosing and attaching the nest used in this
embodiment to a casing. In this case, a gap formed between the nest
and the casing is sealed with seal plates 56, 57 at a part around a
nest inlet. By using this heat exchanger, a cooling ability test
for high temperature compressed air was performed. FIG. 18 is a
sectional view taken along a line A-A in FIGS. 16 and 17, and is a
sectional view at a position of 1/4 of the nest length. FIG. 18
also shows measuring positions of gas temperature. The high
temperature air flowing from the top flows toward the bottom while
the air is cooled in the gas chamber 51. The gap between the nest
and a casing wall 65 is sealed with the seal plate 56. It was found
that a small amount of air leaks from the gap and flows to the nest
outlet side while the air maintains high temperature. Temperature
sensors 61 were provided at the outlets of the gas chambers
disposed at both ends and the gas chambers disposed in the middle
in order to measure the gas temperatures. The temperature sensor 60
was provided to measure the temperature at the inlets. FIG. 19
shows a cross section when the inlets of the gas chambers disposed
at both ends of the nest shown in FIGS. 16, 17 are closed by closed
plates 62. FIG. 19 is a cross sectional view taken along the line
A-A in FIGS. 16 and 17. Temperature sensors were placed on three
lines in the middle to measure the outlet temperatures of the gas
chambers.
[0026] FIG. 20 shows results of the temperature measurement in
these two cases. With respect to symbols shown in FIG. 20, the
first number thereof denotes the test order, and the next number
denotes a position of the gas chamber at which the measurement is
performed, while the last character designates a cross sectional
position. For example, in the case of "1-3A", the first number "1"
is the test number corresponding to the case where five gas lines
and four water chambers are provided, the "3" denotes the third
line of the gas chambers, and the "A" denotes a A-A cross sectional
position. When the first number is "2", this indicates a test
result of the case where the gas chambers disposed at both ends are
closed. As apparent from this drawing, the outlet temperatures of
the gas chambers disposed at both ends are significantly high as
compared with the outlet temperatures of the gas chambers disposed
in the middle. Also, even if the gas chambers disposed at both ends
are closed, the outlet temperatures of the gas chambers disposed in
the middle are little changed. In both tests, of course, the
quantities of heat at the inlets are the same. Accordingly, there
was obtained a test result that the cooling ability is higher in
the case that the gas chambers disposed at both ends are absent,
even if the heat transfer area reduces to be 3/5. This means that,
in the outside gas chambers, the gap between the casing and the
nest becomes wide. The casing is heated by the high temperature
fluid because the heat exchanger according to this embodiment
encloses the nest in the casing. Further, since there is the
leakage of the high temperature fluid, the heat is input from the
outside into the fluid in the gas chambers disposed at both ends of
the nest, thereby the cooling performance is reduced, as
estimated.
[0027] Some embodiments of the present invention based on the
above-described findings will be described referring to FIGS. 1 to
15. FIGS. 1 to 3 are a plane view, a top view, and a side view of a
two-stage screw compressor provided with a heat exchanger according
to the present invention respectively, and in these drawings, a
cover constituting a package is eliminated. FIGS. 4 and 5 are cross
sectional views showing the structure of a casing part in which a
heat exchanger is enclosed.
[0028] The screw compressor according to this embodiment is a
two-stage compressor including a low pressure stage (a first stage)
compressor and a high pressure stage (a second stage) compressor.
Fluid to be treated is air, and a discharge pressure is in order of
approximately 0.7 to 1.0 MPa in gauge pressure. This compressor is
used as a general industrial factory air source, for example. The
configuration of the compressor will be described below in detail.
The low pressure stage compressor 2 and the high pressure stage
compressor 3 are mounted on a speed-up gears casing 5, and a rotor
which is provided in each stage compressor is rotated by a motor 4.
Each air passage for first stage suction, first stage discharge,
second stage suction, and second stage discharge is formed by
dividing the inside of the speed-up gears casing 5 with partition
walls. The high temperature air pressurized in each stage
compressor passes through respective passages, and cooled in an
intercooler and an aftercooler described below. Cooling water is
supplied to these coolers through a cooling water piping 21. The
cooling water is, at first, guided to a water chamber cover 20,
then guided to the nest, thereafter discharged from an outlet
piping 22. The screw compressor has an oil pump 15, an oil cooler
16, a suction filter 11, a volume control valve 10, and other
accessories.
[0029] FIG. 4 shows an inlet part of the intercooler and a state of
the cooler enclosed and attached. In FIG. 4, a compressing stage is
eliminated. The high temperature air pressurized in the first stage
compressor enters into an intercooler chamber 33 through a passage
36 in the casing. FIG. 5 shows an outlet part of the intercooler
and an inlet part into the aftercooler. In FIG. 5, the compressing
stage is also eliminated. The air cooled in the intercooler is
taken into the two-stage compressor through the passage 37. The
high temperature air pressurized in the two-stage compressor flows
into an aftercooler chamber 34 through a passage 38 in the casing.
In this embodiment, a gap formed between the casing and the cooler
nest is sealed around an upper inlet.
[0030] FIGS. 6 and 7 show the nest structure. FIG. 6 is a plane
view of the nest seen from a direction in which the gas flows into
the nest. FIG. 7 is a side view of FIG. 6. In this embodiment, the
high temperature fluid flows from top to bottom, while the cooling
water enters from a lower part so as to be orthogonal to the flow
of the high temperature fluid, and flows out from an upper part.
The nest according to this embodiment has four lines of gas
chambers 41 and five lines of water chambers 42. The chambers are
arranged so that the water chambers 42 are at both ends thereof. On
the other hand, each gas chamber 41 is provided with the water
chambers at both sides. In FIG. 7, the gas 48 flows from top to
bottom, while the cooling water 49 enters from a lower part of the
front side tube plate 43, then changes its direction at a rear side
water chamber case 44, thereafter flows out from an upper part of
the front side tube plate. The two kinds of working fluids flow
while being separated by the partition plate 45 and orthogonal to
each other. Heat is transferred from a high temperature chamber
side to a low temperature chamber side through the partition plate.
Corrugated fins are formed in the gas chamber. The gap between the
nest and the casing is sealed with seal plates 46 and 47 around the
nest inlet. Additionally, a part around the nest outlet may be
sealed also.
[0031] FIG. 8 shows a B-B sectional view of the cooler nest shown
in FIGS. 6 and 7. The water chambers 42 are placed at both ends
thereof and each gas chamber 41 is sandwiched between the water
chambers. By using the cooler nest according to the embodiment, the
high temperature fluid is sufficiently cooled because it passes
through the gas chambers sandwiched between the water chambers.
Additionally, although it is difficult to achieve complete sealing
by sealing the gap between the casing and the nest with the seal
plate 46, a small amount of leaked high temperature fluid does not
heat the fluid flowing in the gas chambers, and alternately the
high temperature fluid is cooled by the cooling water flowing
around the high temperature fluid, so that the leaked gas is also
efficiently cooled.
[0032] Another embodiment of the present invention will be
described referring to FIGS. 9 to 15. This embodiment describes the
case where an intercooler and an aftercooler are individually
constituted, but of course, a plurality of heat exchangers may be
integrated as is the case with the above-described embodiment. A
corrugated-fin-type heat exchanger nest 31 is enclosed in a
container 30 constituting the aftercooler or the intercooler. On
the bottom parts of both, right and left sides of the heat
exchanger nest 31, there are provided fixing members 88 having a
U-shape in its cross section. On both of right and left inner wall
surfaces of the container 30, which correspond to the fixing
members 88, projections 72 are formed.
[0033] By putting a seal member 71 on an upper surface of the
projection 72 and holding the seal member 71 in a groove 87 formed
by the fixing member 88, a space inside of the container 30 is
divided to a space through which the high temperature air 48 flows,
and a space through which the low temperature air 50 cooled by the
heat exchange in the heat exchanger nest 31 flows. In this case,
the heat exchanger nest 31 and the seal member 71 are hermetically
held by closely contacting an inner wall surface 75 of the fixing
member 88 with an outer surface 74 of the seal member 71. The seal
member 71 is a sufficient elastically deformable material such as
rubber. Additionally, with respect to the shape of the seal member
71, a cutout part is formed on the fixing member 88 side, and the
projection side 72 is made to be a taper shape, in consideration of
the adherability with the projection 72 and the fixing member
88.
[0034] In this embodiment constructed so, heat degradation of the
seal member 71 formed from rubber or the like can be reduced
because the seal member 71 is placed on the low temperature air 50
side. Since the seal member 71 is placed under the heat exchanger
nest 31, the seal member 71 is compressively deformed by the weight
of the heat exchanger nest 31, so that the surface pressure can be
securely applied to the seal surface.
[0035] The seal member 71 is an elastically deformable materiel
such as rubber, so that the securely sealing can be performed
without generating any gap even if a surface of the projection 72
of the container 30 is very uneven like a casting surface.
Additionally, the inner wall surface 75 of the fixing member 88 and
an outer surface 26 of the seal member 71 are closely contacted, so
that the occurrence of gaps, which may occur when the heat
exchanger nest 31 is fixed, can be prevented.
[0036] Then, thickness h (see FIG. 9) of the seal member 71 is set
such that a surface 73 of the seal member 71 abutted to the
projection 72 is lower than a bottom surface 8 of the fixing member
88 and a tube plate 89, which bottom surface 8 is a lowest surface
of the heat exchanger nest 31. This allows the seal member 71 to be
compressively deformed by the weight of the heat exchanger nest 31
when the heat exchanger nest 31 is placed in the container 30.
Further, since the surface 73 of the seal member 71 abutted to the
projection 72 and the outer surface 74 of the seal member 71
abutted to the fixing member 88 have smaller cross sectional areas
than the cross sectional area of the seal member 71, so that the
rigidity in the contact surface of the seal member 71 can be small.
Accordingly, it is possible to contact the outer surface 74 of the
seal member 71 to the inner wall surface 75 of the fixing member
88, easily.
[0037] By the way, the inlet air temperature of the heat exchanger
such as an intercooler or an aftercooler used in the screw
compressor reaches to not less than approximately 200 degrees
Celsius, at pressure of approximately 0.1 MPa. The desirable seal
materials for using under such a high temperature are
ethylene-propylene rubber, acrylic rubber, silicone rubber,
fluororubber, and the other material having high heat
resistance.
[0038] A variation of the embodiment shown in FIG. 9 is shown in
FIG. 11. FIG. 11 is a three-side view showing a front view, a top
view, and a side sectional view together. A gas tube seal 76 is
formed by forming a polymeric material having high heat resistance
and high elasticity into a tube shape and by sealing or injecting
gas such as air therein. By using a tube-shaped seal, the
elastically deforming amount can be increased. Particularly, a gas
filling port 77 and the piping for filling the gas from outside of
the container 30 to the gas filling port 77 are provided, so that
reliable sealing can be obtained by only filling the gas in the gas
tube seal 76 and by pressuring the gas, after the heat exchanger
nest 31 is fixed to the container 30. When the heat exchanger nest
31 is removed from the container 30, the heat exchanger nest 31 can
be readily removed from the container 30 only by degassing the tube
76. The preferable materials for the tube is polyacetal,
fluororesin, or the other material having high heat resistance and
elasticity.
[0039] Another variation of the present invention is shown in FIGS.
12A and 12B. In FIG. 12A, the weight of the heat exchanger nest 31
is loaded on the seal member 71a placed on the projection 72
through a clasp 78 provided on the bottom part of the heat
exchanger nest 31. Then, the clasp 78 and the projection 72 are
clamped by using a latch 79. Another clamping way is that, as shown
in FIG. 12B, the seal member 71a is sandwiched between the heat
exchanger fixing plate 80 and the projection 72 provided on the
lowest part of the side of the heat exchanger nest 31, and the bolt
33 which penetrates through the projection 72 and the seal member
71a is screwed to the heat exchanger fixing plate 80. In case of
using either of these ways, the secure sealing can be performed by
elastically deforming the seal member. Additionally, by fixing the
seal member to the heat exchanger nest with the adhesive, the
leakage of the gas between the heat exchanger nest and the seal
member can be more securely prevented.
[0040] Still further variation of the present invention is shown in
FIG. 13. A thin plate 92 is mounted on the bottom surface of the
heat exchanger nest 31 so as to extend in a transverse direction of
the heat exchanger nest 31, and a groove plate 91 having a U-shape
in cross section is mounted to the existing portion with a bolt 90.
Then, the seal member 71 is held in the groove 87 of the groove
plate 91. According to this variation, even if the fixing bolt 90
is loosed and dropped during operation of the heat exchanger, it
can be prevented that the dropped bolt 90 flows to the gas flow
passage, because the receiving surface 93 is formed in the seal
member 71.
[0041] FIGS. 14 and 15 show a partly sectional perspective views of
a heat exchanger using the seal members 71 and 71a shown in the
above-described embodiments and variations. In FIG. 15, a bottom
surface is shown on the left side of the figure, and a right side
surface is shown on the lower side of the figure, for convenient of
the description. The high temperature air 48 discharged from the
compressor or the like is suctioned from the suction port 28, and
performs the heat exchange with the cooling water in the heat
exchanger nest 31 to become low temperature air 50, then the air is
discharged from a discharging port 29 to the outside. On the side
of the outlet and inlet port of the cooling water, a water chamber
63 is provided. The heat exchanger nest 31 has the water chambers
(lines) and the gas chambers (lines) as described in detail in
above-described embodiments, and they have the corrugated fins 26,
27. In FIG. 15, tube plates 27 are placed between the chambers, and
an outer bar 29 is provided on the tube plate side.
[0042] According to the embodiments and variations described above,
the heat exchanger nest can be readily removed from the container
of the heat exchanger, and the sealing can be securely preformed,
so that the reliable and efficient heat exchanger can be obtained.
Additionally, cleaning and checking can be performed only by
removing the cover, so that the maintenance ability is improved.
Further, by decreasing the temperature of the working fluid at the
outlet of the heat exchanger, the compressor power is reduced,
which can contribute to the energy saving.
[0043] As described above in detail, in the compact type heat
exchanger according to the present invention, the number of low
temperature chambers is larger than that of the high temperature
chambers by one chamber (one line), and the low temperature
chambers are disposed at both ends, so that the compact heat
exchanger having excellent cooling performance can be obtained.
Further, the sealing ability inside the heat exchanger can be
improved.
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