U.S. patent application number 11/812254 was filed with the patent office on 2007-10-18 for cooling device for electronic apparatus.
This patent application is currently assigned to ABB OY. Invention is credited to Matti Kauranen, Mika Sares, Mika Silvennoinen.
Application Number | 20070242429 11/812254 |
Document ID | / |
Family ID | 34112680 |
Filed Date | 2007-10-18 |
United States Patent
Application |
20070242429 |
Kind Code |
A1 |
Kauranen; Matti ; et
al. |
October 18, 2007 |
Cooling device for electronic apparatus
Abstract
The present invention relates to a cooling device for an
electronic apparatus comprising: a cooling element to be connected
to an electronic component for receiving the heat load generated by
the electronic component, an inlet port, an outlet port and a fan
for bringing air to flow from the inlet port via the cooling
element to the outlet port to cool the cooling element by means of
the air flow. In order to achieve a simple device improving the
reliability the cooling device comprises at least one return
channel, through which some of the air flowing from the cooling
element towards the outlet port is conducted to an electronic space
to cool the electronic space, and that a forepart of the return
channel is arranged in a place where the air flow from the cooling
element towards the outlet port is colder than the air flowing from
the cooling element on average.
Inventors: |
Kauranen; Matti; (Espoo,
FI) ; Silvennoinen; Mika; (Espoo, FI) ; Sares;
Mika; (Roykka, FI) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
ABB OY
Helsinki
FI
|
Family ID: |
34112680 |
Appl. No.: |
11/812254 |
Filed: |
June 15, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11335271 |
Jan 20, 2006 |
|
|
|
11812254 |
Jun 15, 2007 |
|
|
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Current U.S.
Class: |
361/692 |
Current CPC
Class: |
H05K 7/20154
20130101 |
Class at
Publication: |
361/692 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2005 |
FI |
20055029 |
Claims
1. A cooling device for an electronic apparatus, the cooling device
comprising: a cooling element to be connected to an electronic
component for receiving a heat load generated by the electronic
component, an inlet opening, an outlet opening and a fan for
bringing air to flow from the inlet opening via the cooling element
to the outlet opening for cooling the cooling element with the air
flow, and at least one return channel, through which some of the
air flowing from the cooling element towards the outlet opening is
conducted to an electronic space to cool the electronic space, and
wherein a forepart of the return channel is arranged in a place,
where the air flowing from the cooling element towards the outlet
port is colder than the air flowing from the cooling element on
average.
2. A cooling device as claimed in claim 1, wherein the return
channel continues from the electronic space to the inlet opening in
order to conduct the air conducted to the electronic space to the
inlet opening.
3. A cooling device as claimed in claim 1, wherein a control
element is arranged in connection with the forepart of the return
channel, the control element directing some of the air flowing from
the cooling element to the outlet port to the return channel.
4. A cooling device as claimed in claim 3, wherein the control
element is arranged to delimit an area from a flow area of the
cooling element, the area being located as far as possible from an
electronic component or the electronic components connected to the
cooling element.
5. A cooling device as claimed in claim 1, wherein the fan is
arranged in the flow direction before the cooling element to blow
air to the cooling element and to suck air from the inlet port.
6. A cooling device as claimed in claim 1, wherein the cooling
element comprises plate-like cooling fins arranged in parallel and
at a distance from one another and air flowing therebetween.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional Application of Application
Ser. No. 11/335,271, filed Jan. 20, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to a cooling device for an
electronic apparatus that enables to provide simple and efficient
cooling for an electronic component fastened to a cooling element
and in an electronic space of the electronic apparatus. The
invention also relates to a cooling method.
DESCRIPTION OF THE PRIOR ART
[0003] A solution is previously known, in which cooling is carried
out in electronic apparatuses such that the power electronic
component is fastened to a cooling element, through which an air
flow is arranged by means of a fan. Thus the heat load received
from the power electronic component of the cooling element is
transferred through the cooling element to the air flowing out from
the electronic apparatus. Since the electronic apparatus is also
provided with an electronic space, which includes other components
requiring cooling, the known solution employs another fan, and the
air flow provided by means thereof is directed through the
electronic space in order to achieve adequate cooling in the
electronic space.
[0004] A disadvantage with the solution mentioned above is that it
requires two fans in order to ensure adequate cooling. Another
disadvantage is that cold air is brought from outside the device to
the electronic space that may be damp. Bringing such air to the
electronic space increases significantly the risk of corrosion and
the risk of malfunctions caused by corrosion.
[0005] Solutions are also previously known in which the same air
flow provided with a single fan is employed to cool a cooling
element connected to the power electronic component and the
electronic space. Then the air flowing from outside the device
through the inlet port is at first conducted through the electronic
space, and thereafter through the cooling element to the outlet
port. Consequently the need for two separate fans is avoided.
However, what remains a problem is still the fact that the cold air
flowing from outside the device may cause corrosion in the
electronic space.
BRIEF DESCRIPTION OF THE INVENTION
[0006] It is an object of the present invention to solve the
problem described above and to provide a cooling solution to be
used that is simple and improves the reliability of the device in
the long run. This object is achieved with a cooling device
according to the accompanying independent claim 1 and with a method
according to the accompanying independent claim 7.
[0007] In the invention some of the air that flows through the
cooling element is separated to be circulated through the
electronic space. Thus conducting cold and possibly damp air to the
electronic space is avoided. An adequate cooling in the electronic
space is achieved by separating air from the air flow flowing
towards the outlet port from the cooling element, the separated air
being colder than the air flowing from the cooling element on
average. The temperature of the separated air flow is therefore
lower than the temperature of the air passing through the cooler on
average. Conducting air that is too hot to the electronic space is
thus avoided.
[0008] In a preferred embodiment of the invention a return channel
that is used to bring air to the electronic space continues from
the electronic space to the inlet port of the device. This
preferred embodiment provides such an advantage that the flow of
air flowing through the electronic space becomes more efficient,
since the lower pressure prevailing at the inlet port provides a
suction effect assisting the flow of air.
[0009] The preferred embodiments of the cooling device and the
cooling method according to the invention are disclosed in the
accompanying dependent claims 2 to 6 and 8 to 9.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the following the invention will be explained in greater
detail by way of example with reference to the accompanying
drawings, in which:
[0011] FIGS. 1 and 2 illustrate a first preferred embodiment of the
invention,
[0012] FIGS. 3 to 5 illustrate a second preferred embodiment of the
invention, and
[0013] FIGS. 6 to 8 illustrate alternative designs of the forepart
of a return channel.
DESCRIPTION OF EMBODIMENTS
[0014] FIGS. 1 and 2 illustrate a first preferred embodiment of the
invention. FIG. 1 shows a cooling element 1. It is assumed in the
example case shown in the Figures that the cooling element is
formed of parallel plate-like cooling fins, between which air is
able to flow.
[0015] An electronic component 2 is connected to the surface of the
cooling element 1, the number of the electronic components in the
case shown in FIGS. 1 and 2 is two. The heat load generated by the
electronic components is thus transferred through the cooling
element to the flow of air flowing through the cooling element. In
FIG. 1 reference numeral 3 indicates areas of a flow area of the
cooling element that are located furthest from the electronic
components. When air flows through the cooling element 1 some of
the air flow that is discharged from the cooling element 1 is
colder in the areas 3, which are located furthest from the
electronic components 2.
[0016] FIG. 2 illustrates the cooling element 1 shown in FIG. 1
when it is mounted in an electronic apparatus 4, which may for
instance be a frequency converter. For clarity, the electronic
apparatus is shown in FIG. 2 without an upper cover. A fan 5 (which
may in practice be encased) sucks air from outside the apparatus 4
through an inlet port 6. The air flow created passes through the
cooling element to the outlet port 7, from where it is discharged
outside the apparatus 4. The cooling element 1 and the air flowing
therethrough therefore cools the electronic components 2 connected
to the cooling element.
[0017] Since other components requiring cooling may also be located
in the electronic space 8 of the apparatus 4 than only electronic
components 2, a return channel 10 is arranged in the apparatus 4 in
accordance with the invention that allows conducting some of the
flow of air flowing from the cooling element 1 towards the outlet
port 7 to the electronic space 8 in order to cool this. In the case
shown in FIG. 2 a control element 9 is arranged at the forepart of
the return channel, the control element being located in the air
flow flowing from the cooling element 1 to the outlet port 7. The
control element is arranged in a place, where the air flow from the
cooling element 1 towards the outlet port 7 is colder than the air
flow from the cooling element on average. In practice such air
flows from areas 3 shown in FIG. 1.
[0018] In the case of FIG. 2 the electronic space 8 itself forms a
part of the return channel, in other words the surrounding walls
that delimit the space through which the air conducted to the
electronic space flows. The rear wall of the electronic space is
provided with openings 11, through which the air flow conducted to
the electronic space can be discharged from the electronic space.
The openings 11 are preferably formed so that they conduct the air
discharged from the electronic space to the inlet port 6. In
addition, a case is preferably arranged around the fan, into which
case the openings 11 lead. Such a solution allows improving the
flow through the electronic space, since the low pressure at the
inlet port 6 generates a suction to the electronic space through
the openings 11.
[0019] FIGS. 3 to 5 illustrate a second preferred embodiment of the
invention. FIG. 3 shows an exploded view, FIG. 4 shows a rear view
and FIG. 5 shows a front view of the electronic apparatus 4'. The
embodiment shown in FIGS. 3 to 5 corresponds to a great extent with
the embodiment shown in FIGS. 1 to 2, and therefore it will be
described in the following primarily by presenting the differences
between the embodiments.
[0020] In the embodiment shown in FIGS. 3 to 5 electronic
components 2 are fastened to the cooling element on two opposite
sides. The heat load generated by the electronic components 2 can
thus be transferred through the cooling element to the flow of air
flowing through the cooling element. For practical reasons the air
flow conducted to the electronic space that is used to cool the
other components located in the electronic space, is in this
embodiment taken from the upper and lower edges of the cooling
element (indicated in more detail in FIGS. 6 to 8). Covers 12' and
13' of the device delimit the electronic space, which covers
further delimit the return channel inside them. The air conducted
to the electronic space is discharged from the electronic space
through the openings 11 to the vicinity of the inlet port of a fan
5'.
[0021] FIGS. 6 to 8 illustrate alternative designs of the forepart
of the return channel. The solutions shown in FIGS. 6 to 8 can be
utilized for instance in connection with the embodiment shown in
FIGS. 3 to 5.
[0022] In the case shown in FIG. 6 a control element 9' that covers
a part of the flow area of the cooling element is formed at the
lower edge by means of the frames in the electronic apparatus. The
control element 9' thus separates some of the flow of air flowing
from the cooling element and conducts the separated air flow to the
return channel. The control element 9' is arranged such that it is
located in a place where air flows that is colder than the air
flowing from the cooling element on average.
[0023] In FIG. 7 a control element 9'' is formed from the upper
edge of a plate bent downwards into the air flow. The plate directs
some of the air flowing from the cooling element to the return
channel. The control element 9'' is arranged such that it is
located in a place where air flows that is colder than the air
flowing from the cooling element on average.
[0024] In the case illustrated in FIG. 8 a separate control element
is not used. In contrast an opening 14 forming the forepart of the
return channel is arranged in a place where air flows that is
colder than the air flowing from the cooling element on average. In
order for a sufficient amount of air to flow into the return
channel it is preferable that the return channel ends at the inlet
port in this embodiment so that a suction can be created in the
electronic space as described previously.
[0025] Embodiments have above been described with reference to the
Figures, in which the control element that is used to direct some
of the flow of air flowing from the cooler to the outlet port to
the return channel is in relation to the cooler formed of a
separate part. However, it is possible in accordance with the
invention that the control element is completely or partly formed
of a cooling element. Thus the design of the cooling element is
such that air from the air flow passing therethrough is directed
from a desired point to the return channel.
[0026] It is to be understood that the description and the Figures
associated therewith are merely intended to illustrate the present
invention. Various variations and modifications of the invention
will be apparent to those skilled in the art without deviating from
the scope of the invention.
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