U.S. patent application number 14/870962 was filed with the patent office on 2017-03-30 for two-phase jet impingement cooling devices and electronic device assemblies incorporating the same.
This patent application is currently assigned to Toyota Motor Engineering & Manufacturing North America, Inc.. The applicant listed for this patent is Toyota Motor Engineering & Manufacturing North America, Inc.. Invention is credited to Ercan M. Dede, Shailesh N. Joshi.
Application Number | 20170094837 14/870962 |
Document ID | / |
Family ID | 58406202 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170094837 |
Kind Code |
A1 |
Joshi; Shailesh N. ; et
al. |
March 30, 2017 |
TWO-PHASE JET IMPINGEMENT COOLING DEVICES AND ELECTRONIC DEVICE
ASSEMBLIES INCORPORATING THE SAME
Abstract
Two-phase jet impingement cooling devices and electronic device
assemblies are disclosed. In one embodiment, a cooling device
includes a manifold having a fluid inlet surface, a fluid outlet
surface defining an outlet manifold, and a fluid outlet. The fluid
inlet surface includes an inlet channel fluidly coupled to a first
jet region and a second jet region each including a plurality of
jet orifices and a plurality of surface features extending from the
fluid inlet surface. A target plate is coupled to the fluid outlet
surface of the manifold that includes a target surface, a first
heat sink, and a second heat sink. A cover plate is coupled to the
fluid inlet surface of the manifold, which includes a fluid inlet
port fluidly coupled to the inlet channel of the manifold, and a
fluid outlet port fluidly coupled to the fluid outlet of the
manifold.
Inventors: |
Joshi; Shailesh N.; (Ann
Arbor, MI) ; Dede; Ercan M.; (Ann Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toyota Motor Engineering & Manufacturing North America,
Inc. |
Erlanger |
KY |
US |
|
|
Assignee: |
Toyota Motor Engineering &
Manufacturing North America, Inc.
Erlanger
KY
|
Family ID: |
58406202 |
Appl. No.: |
14/870962 |
Filed: |
September 30, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 7/20345 20130101;
H05K 7/20327 20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. A cooling device comprising: a manifold comprising a fluid inlet
surface, a fluid outlet surface defining an outlet manifold, and a
fluid outlet, wherein: the fluid outlet surface is opposite the
fluid inlet surface; the fluid inlet surface comprises an inlet
channel fluidly coupled to a first jet region and a second jet
region; the first jet region and the second jet region each
comprise a plurality of jet orifices and a plurality of surface
features extending from the fluid inlet surface; an individual
surface feature of the plurality of surface features is positioned
adjacent an individual jet orifice of the plurality of jet
orifices; the first jet region and the second jet region are
symmetrical about a line disposed in a center of the inlet channel;
and the fluid outlet is fluidly coupled to the outlet manifold; a
target plate coupled to the fluid outlet surface of the manifold,
the target plate comprising a target surface, a first heat sink at
the target surface, and a second heat sink at the target surface,
wherein the first heat sink is aligned with the first jet region of
the manifold, and the second heat sink is aligned with the second
jet region; and a cover plate coupled to the fluid inlet surface of
the manifold, the cover plate comprising a fluid inlet port fluidly
coupled to the inlet channel of the manifold, and a fluid outlet
port fluidly coupled to the fluid outlet of the manifold.
2. The cooling device of claim 1, wherein each of the plurality of
jet orifices of the first jet region and the plurality of jet
orifices of the second jet region is arranged in an array.
3. The cooling device of claim 1, wherein the first heat sink is
configured as a first array of pins and the second heat sink is
configured as a second array of pins.
4. The cooling device of claim 1, wherein the fluid inlet port has
a channel comprising a ninety degree turn.
5. The cooling device of claim 1, wherein: the outlet manifold is
defined by a plurality of walls; the fluid outlet is disposed
between a first wall and a second wall of the plurality of walls;
and the first wall and the second wall are angled outwardly away
from a central region of the outlet manifold.
6. The cooling device of claim 1, wherein the first jet region and
the second jet region are fluidly coupled to an end of the inlet
channel.
7. The cooling device of claim 1, wherein the inlet channel
comprises a ninety degree turn.
8. The cooling device of claim 1, wherein: each of the first jet
region and the second jet region is defined by a perimeter wall;
and the perimeter wall has a non-linear shape comprising a
plurality of convex regions such that each convex region is
adjacent to an individual jet orifice of the plurality of jet
orifices.
9. The cooling device of claim 1, wherein the target surface, the
first heat sink, and the second heat sink have a porous
surface.
10. A cooling device comprising: a manifold comprising a fluid
inlet surface, a fluid outlet surface defining an outlet manifold,
and a fluid outlet, wherein: the fluid inlet surface comprises an
inlet channel fluidly coupled to a jet region; the jet region
comprises a plurality of jet orifices and a plurality of surface
features extending from the fluid inlet surface; an individual
surface feature of the plurality of surface features is positioned
adjacent an individual jet orifice of the plurality of jet
orifices; and the fluid outlet is fluidly coupled to the outlet
manifold; a target plate coupled to the fluid outlet surface of the
manifold, the target plate comprising a target surface and a heat
sink at the target surface that is aligned with the jet region of
the manifold, wherein the heat sink comprises one or more walls
defining a central impingement region, and a plurality of channels
extending through the one or more walls; and a cover plate coupled
to the fluid inlet surface of the manifold, the cover plate
comprising a fluid inlet port fluidly coupled to the inlet channel
of the manifold, and a fluid outlet port fluidly coupled to the
fluid outlet of the manifold.
11. The cooling device of claim 10, wherein the plurality of
channels of the heat sink is a plurality of bores extending through
the one or more walls.
12. The cooling device of claim 10, wherein the plurality of
channels of the heat sink is a plurality of open grooves through
the one or more walls.
13. The cooling device of claim 10, wherein the target surface and
the heat sink have a porous surface.
14. The cooling device of claim 10, wherein: the jet region is
defined by a perimeter wall; and the perimeter wall has a
non-linear shape comprising a plurality of convex regions, where
each convex region is adjacent to an individual jet orifice of the
plurality of jet orifices.
15. The cooling device of claim 10, wherein: the fluid inlet
surface further comprises an additional jet region, the additional
jet region comprising an additional plurality of jet orifices and
an additional plurality of surface features extending from the
fluid inlet surface; an individual surface feature of the
additional plurality of surface features is positioned adjacent an
individual jet orifice of the additional plurality of jet orifices;
the jet region and the additional jet region are symmetrical about
a line disposed in a center of the inlet channel; and the target
plate comprises an additional heat sink at the target surface, the
additional heat sink comprising an additional one or more walls
defining an additional central impingement region, and an
additional plurality of channels through the additional one or more
walls.
16. The cooling device of claim 15, wherein the jet region and the
additional jet region are fluidly coupled to an end of the inlet
channel.
17. The cooling device of claim 15, wherein the inlet channel
comprises a ninety degree turn.
18. An electronic device assembly comprising: a manifold comprising
a fluid inlet surface, a fluid outlet surface defining an outlet
manifold, and a fluid outlet, wherein: the fluid outlet surface is
opposite the fluid inlet surface; the fluid inlet surface comprises
an inlet channel fluidly coupled to a first jet region and a second
jet region; the first jet region and the second jet region each
comprise a plurality of jet orifices and a plurality of surface
features extending from the fluid inlet surface; an individual
surface feature of the plurality of surface features is positioned
adjacent an individual jet orifice of the plurality of jet
orifices; the first jet region and the second jet region are
symmetrical about a line disposed in a center of the inlet channel;
and the fluid outlet is fluidly coupled to the outlet manifold; a
target plate coupled to the fluid outlet surface of the manifold,
the target plate comprising a heat receiving surface, a target
surface, a first heat sink at the target surface, and a second heat
sink at the target surface, wherein the first heat sink is aligned
with the first jet region of the manifold, and the second heat sink
is aligned with the second jet region; a cover plate coupled to the
fluid inlet surface of the manifold, the cover plate comprising a
fluid inlet port fluidly coupled to the inlet channel of the
manifold, and a fluid outlet port fluidly coupled to the fluid
outlet of the manifold; and a first electronic device and a second
electronic device, wherein the first electronic device and the
second electronic device are thermally coupled to the heat
receiving surface such that the first electronic device and the
second electronic device are opposite the first heat sink and the
second heat sink, respectively.
19. The electronic device assembly of claim 18, wherein: each of
the first jet region and the second jet region is defined by a
perimeter wall; and the perimeter wall has a non-linear shape
comprising a plurality of convex regions such that each convex
region is adjacent to an individual jet orifice of the plurality of
jet orifices.
20. The electronic device assembly of claim 18, wherein the inlet
channel comprises a ninety degree turn.
Description
TECHNICAL FIELD
[0001] The present specification generally relates to cooling
devices and, more particularly, to two-phase, jet impingement
cooling devices for cooling heat generating devices.
BACKGROUND
[0002] Heat generating devices, such as power semiconductor
devices, may be coupled to a heat spreader to remove heat and lower
the maximum operating temperature of the heat generating device. In
some applications, cooling fluid may be used to receive heat
generated by the heat generating device by convective thermal
transfer, and remove such heat from the heat generating device. For
example, jet impingement may be used to cool a heat generating
device by directing impingement jets of cooling fluid onto the heat
generating device or a target surface that is thermally coupled to
the heat generating device. Additionally, jet impingement may also
be combined with two-phase cooling, where the heat generating
device is cooled by the phase change of the coolant fluid from a
liquid to a vapor.
[0003] However, as the operating temperature of heat generating
devices increases, more efficient cooling devices may be needed.
Non-uniform velocity of impingement jets of cooling fluid may
provide for non-uniform cooling of the heat generating devices.
Additionally, cooling fluid that does not fully change from a
liquid to a vapor may limit the efficiency of the cooling
device.
[0004] Accordingly, a need exists for alternative cooling devices
that provide uniform fluid flow through jet orifices with low flow
resistance as well as efficient phase change of cooling fluid from
a liquid to a vapor.
SUMMARY
[0005] In one embodiment, a cooling device includes a manifold
having a fluid inlet surface, a fluid outlet surface defining an
outlet manifold, and a fluid outlet. The fluid outlet surface is
opposite the fluid inlet surface. The fluid inlet surface includes
an inlet channel fluidly coupled to a first jet region and a second
jet region. The first jet region and the second jet region each
include a plurality of jet orifices and a plurality of surface
features extending from the fluid inlet surface. An individual
surface feature of the plurality of surface features is positioned
adjacent an individual jet orifice of the plurality of jet
orifices. The first jet region and the second jet region are
symmetrical about a line disposed in a center of the inlet channel.
The fluid outlet is fluidly coupled to the outlet manifold. The
cooling device further includes a target plate coupled to the fluid
outlet surface of the manifold. The target plate includes a target
surface, a first heat sink at the target surface, and a second heat
sink at the target surface. The first heat sink is aligned with the
first jet region of the manifold, and the second heat sink is
aligned with the second jet region. The cooling device also
includes a cover plate coupled to the fluid inlet surface of the
manifold. The cover plate includes a fluid inlet port fluidly
coupled to the inlet channel of the manifold, and a fluid outlet
port fluidly coupled to the fluid outlet of the manifold.
[0006] In another embodiment, a cooling device includes a manifold
having a fluid inlet surface, a fluid outlet surface defining an
outlet manifold, and a fluid outlet. The fluid inlet surface
includes an inlet channel fluidly coupled to a jet region. The jet
region includes a plurality of jet orifices and a plurality of
surface features extending from the fluid inlet surface. An
individual surface feature of the plurality of surface features is
positioned adjacent an individual jet orifice of the plurality of
jet orifices. The fluid outlet is fluidly coupled to the outlet
manifold. The cooling device further includes target plate coupled
to the fluid outlet surface of the manifold. The target plate
includes a target surface and a heat sink at the target surface
that is aligned with the jet region of the manifold. The heat sink
includes one or more walls defining a central impingement region,
and a plurality of channels extending through the one or more
walls. The cooling device also includes a cover plate coupled to
the fluid inlet surface of the manifold. The cover plate includes a
fluid inlet port fluidly coupled to the inlet channel of the
manifold, and a fluid outlet port fluidly coupled to the fluid
outlet of the manifold.
[0007] In yet another embodiment, an electronic device assembly
includes a manifold having a fluid inlet surface, a fluid outlet
surface defining an outlet manifold, and a fluid outlet. The fluid
outlet surface is opposite the fluid inlet surface. The fluid inlet
surface includes an inlet channel fluidly coupled to a first jet
region and a second jet region. The first jet region and the second
jet region each include a plurality of jet orifices and a plurality
of surface features extending from the fluid inlet surface. An
individual surface feature of the plurality of surface features is
positioned adjacent an individual jet orifice of the plurality of
jet orifices. The first jet region and the second jet region are
symmetrical about a line disposed in a center of the inlet channel.
The fluid outlet is fluidly coupled to the outlet manifold. The
electronic device assembly further includes a target plate coupled
to the fluid outlet surface of the manifold. The target plate
includes a target surface, a first heat sink at the target surface,
and a second heat sink at the target surface. The first heat sink
is aligned with the first jet region of the manifold, and the
second heat sink is aligned with the second jet region. The
electronic device assembly also includes a cover plate coupled to
the fluid inlet surface of the manifold. The cover plate includes a
fluid inlet port fluidly coupled to the inlet channel of the
manifold, and a fluid outlet port fluidly coupled to the fluid
outlet of the manifold. The electronic device assembly further
includes a first electronic device and a second electronic device
that are thermally coupled to the heat receiving surface such that
the first electronic device and the second electronic device are
opposite the first heat sink and the second heat sink,
respectively.
[0008] These and additional features provided by the embodiments
described herein will be more fully understood in view of the
following detailed description, in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The embodiments set forth in the drawings are illustrative
and exemplary in nature and not intended to limit the subject
matter defined by the claims. The following description of the
illustrative embodiments can be understood when read in conjunction
with the following drawings, where like structure is indicated with
like reference numerals and in which:
[0010] FIG. 1 schematically depicts a perspective view of an
example cooling device according to one or more embodiments
described and illustrated herein;
[0011] FIG. 2 schematically depicts an exploded perspective view of
the example cooling device depicted in FIG. 1 according to one or
more embodiments described and illustrated herein;
[0012] FIG. 3 schematically depicts an example fluid inlet surface
of a manifold of a cooling device according to one or more
embodiments described and illustrated herein;
[0013] FIG. 4 schematically depicts an example fluid outlet surface
of a manifold of a cooling device according to one or more
embodiments described and illustrated herein;
[0014] FIG. 5A schematically depicts a top-down view of a portion
of a target plate and an example pin fin heat sink according to one
or more embodiments described and illustrated herein;
[0015] FIG. 5B schematically depicts a side elevation view of the
partial target plate and the pin-fin heat sink depicted in FIG.
5A;
[0016] FIG. 6A schematically depicts a top-down view of a portion
of a target plate and an example heat sink having open channels
according to one or more embodiments described and illustrated
herein;
[0017] FIG. 6B schematically depicts a side elevation view of the
partial target plate and the heat sink depicted in FIG. 6A;
[0018] FIG. 7A schematically depicts a top-down view of a portion
of a target plate and an example heat sink having closed channels
according to one or more embodiments described and illustrated
herein;
[0019] FIG. 7B schematically depicts a side elevation view of the
partial target plate and the heat sink depicted in FIG. 7A;
[0020] FIG. 8 graphically depicts the heat transfer coefficient
with respect to heat flux for a plurality of different heat sinks
of simulated cooling devices according to one or more embodiments
described and illustrated herein;
[0021] FIG. 9 graphically depicts a simulation of the pressure drop
with respect to heat flux within a cooling device for a plurality
of different heat sinks of simulated cooling devices according to
one or more embodiments described and illustrated herein;
[0022] FIG. 10 schematically depicts cooling fluid flow through the
fluid inlet surface of the manifold depicted in FIG. 3 according to
one or more embodiments described and illustrated herein; and
[0023] FIG. 11 schematically depicts cooling fluid flow through the
fluid outlet surface of the manifold depicted in FIG. 5 according
to one or more embodiments described and illustrated herein.
DETAILED DESCRIPTION
[0024] Referring generally to the figures, embodiments of the
present disclosure are directed to cooling devices and, more
particularly, to two-phase jet impingement cooling devices for
cooling heat generating devices. The cooling devices described
herein may be useful in cooling heat generating devices such as
power electronic devices. As an example and not a limitation, the
cooling devices described herein may be utilized to cool power
electronic devices found in inverter circuits employed by electric
or hybrid-electric vehicles. Such power electronic devices, such as
silicon carbide electronic devices, may operate at relatively high
operating temperatures (e.g., 200.degree. C. and greater). The
cooling devices described herein provide impingement jets of
cooling fluid that strike a target surface to which the heat
generating device is thermally coupled. Thermal energy is
transferred from the target surface to the cooling fluid that
impinges the target surface. The cooling fluid is heated by the
heat generating device such that it changes phase from a liquid to
a vapor, thereby further cooling the heat generating device.
[0025] The cooling devices described herein include a manifold
having an inlet surface that provides an inlet channel and two
symmetrical jet impingement regions. The two jet impingement
regions each have a plurality of jet orifices through which cooling
fluid flows as impingement jets toward a heat sink and target
surface. Each of the jet impingement regions have a perimeter wall
and a plurality of surface features that are optimized to uniformly
distribute the flow of cooling fluid across the plurality of jet
orifices with relatively low flow resistance (i.e., minimal
pressure drop). Optimized heat sink configurations that promote
phase change of the cooling fluid are also described herein. In
some embodiments, porous surfaces are provided at the target
surface and/or heat sink to further promote phase change of the
cooling fluid. The compact, multi-layer design of the cooling
devices described herein minimizes the overall height of the
cooling device and thus reduces the volume needed for efficient
high-performance cooling.
[0026] Various embodiments of cooling devices and electronic device
assemblies are described in detail herein.
[0027] Referring now to FIG. 1, an example cooling device 100 is
schematically depicted in a perspective view. The example cooling
device 100 may be included as a component in an electronic assembly
for the purpose of cooling one or more power electronic devices,
for example. However, it should be understood that the cooling
device 100 may be utilized in applications other than electronics
applications.
[0028] The cooling device depicted in FIG. 1 generally includes a
cover plate 110, a manifold 120, and a target plate 140. The cover
plate 110 is coupled to a fluid inlet surface of the manifold 120,
and the target plate 140 is coupled to a fluid outlet surface of
the manifold. In some embodiments, the cover plate 110, the
manifold 120 and the target plate 140 may be coupled together by
through holes 114 and mechanical fasteners (e.g., bolts, nuts,
screws, and the like (not shown)). However, it should be understood
that the cover plate 110, the manifold 120 and the target plate 140
may be coupled together by other means, such as by soldering,
brazing, and the like.
[0029] An upper surface 111 of the example cover plate 110 includes
an inlet port 115 and an outlet port 112 extending therefrom. In
the illustrated embodiment, the inlet port 115 includes an inlet
surface 116 having a fluid inlet passage 117 opening disposed
therein. The example fluid inlet passage 117 has a ninety-degree
turn such that cooling fluid entering the fluid inlet passage 117
exits the inlet port 115 into the manifold 120 at an angle that is
transverse to the upper surface 111 of the cover plate 110 (e.g.,
orthogonal to the upper surface 111 of the cover plate 110).
[0030] A fluid outlet passage 113 is disposed within the fluid
outlet port 112. The fluid outlet passage 113 may also have a
ninety-degree turn in some embodiments. As described in more detail
below, the fluid outlet port 112 is fluidly coupled to the fluid
outlet surface of the manifold 120.
[0031] Although not depicted in FIG. 1, the fluid inlet port 115
and the fluid outlet port 112 may include fluid couplings to
fluidly couple fluid lines for introducing and removing cooling
fluid to and from the cooling device 100.
[0032] Referring now to FIG. 2, an exploded view of the example
cooling device 100 depicted in FIG. 1 is illustrated. As stated
above, the cover plate 110 is coupled to a fluid inlet surface 121
of the manifold 120, and the target plate 140 is coupled to a fluid
outlet surface 125 (FIG. 4) of the manifold 120. The manifold 120
may include through holes 124 or other mechanical features to
assist in coupling the components together.
[0033] The manifold 120 may be fabricated from any suitable
thermally conductive material, such as, without limitation,
aluminum, copper, and thermally conductive polymers. It should be
understood that other materials may also be utilized.
[0034] Referring to both FIG. 2 and FIG. 3, the fluid inlet surface
121 of the manifold 120 defines an inlet manifold 129.
Particularly, the inlet manifold 129 of the illustrated embodiment
includes an inlet channel 122, a first jet region 123a, and a
second jet region 123b that are configured as recesses within the
fluid inlet surface 121. The example fluid inlet surface 121
further includes a gasket groove 131 around a perimeter of the
fluid inlet surface 121 operable to receive a gasket (not shown) to
seal the cover plate 110 to the fluid inlet surface 121 of the
manifold 120.
[0035] The fluid inlet channel 122 is fluidly coupled to the fluid
inlet passage 117 of the inlet port 115, and directs cooling fluid
from the inlet port 115 toward the first jet region 123a and the
second jet region 123b. In the illustrated embodiment, the fluid
inlet channel 122 includes a ninety-degree turn such that it has an
"L" shape. However, it should be understood that, in other
embodiments, the fluid inlet channel 122 may possess other shapes,
such as a straight channel with no turns, for example.
[0036] The first jet region 123a and the second jet region 123b are
each fluidly coupled to an end of the fluid inlet channel 122 such
that each receives cooling fluid from the fluid inlet channel 122.
In the illustrated embodiment, each of the first and second jet
regions 123a, 123b have a non-linear perimeter wall 128 that
provide lobe-shaped jet regions extending from the end of the fluid
inlet channel 122 and back toward an edge of the manifold 120
proximate the inlet port 115. The perimeter wall 128 also defines a
protrusion 133 that extends in a direction toward the fluid inlet
channel 122. As described in more detail below, the protrusion 133
is configured to equally distribute cooling fluid to both the first
jet region 123a and the second jet region 123b.
[0037] Each of the first jet region 123a and the second jet region
123b includes a plurality of jet orifices 127 that receives the
cooling fluid from the fluid inlet channel 122 and directs it
toward the target plate 140 as a plurality of impingement jets of
cooling fluid. In the illustrated embodiment, the plurality of jet
orifices 127 of the first jet region 123a and the second jet region
123b is configured as an array of jet orifices 127. However, it
should be understood that embodiments are not limited thereto. The
jet orifices 127 may be arranged in an arbitrary manner, for
example.
[0038] Each of the first jet region 123a and the second jet region
123b include a plurality of surface features 126 extending from the
fluid inlet surface 121. Each individual surface feature 126 is
positioned adjacent an individual jet orifice 127. The shape of the
perimeter wall 128, and the shape and placement of the individual
surface features 126, are optimized to provide for substantially
uniform flow of cooling fluid through each of the jet orifices 127.
For example, the size of surface features 126 closer to fluid inlet
channel 122 may be larger than surface features 126 located farther
away from fluid inlet channel 122 because of the greater volume of
cooling fluid near the fluid inlet channel 122 than further away.
The perimeter wall 128 has a non-linear configuration to optimize
cooling fluid flow toward the plurality of jet orifices 127.
Particularly, the perimeter wall 128 has a convex region 135
adjacent to each jet orifice 127 positioned as a perimeter jet
orifice of the plurality of jet orifices.
[0039] The shape of the perimeter wall 128 and the shape and
placement of the plurality of surface features 126 are optimized to
ensure uniform flow distribution as well as to minimize pressure
drop. Computerized methods of determining the optimized shape of
the perimeter wall 128 and plurality of surface features 126
include, but are not limited to, those described in U.S. Pat. No.
8,516,831, which is hereby incorporated by reference in its
entirety. In the illustrated embodiment, the features of the first
jet region 123a and the second jet region 123b are symmetrical
about a center line A of the fluid inlet channel 122.
[0040] Referring now to FIGS. 2 and 4, an outlet manifold 132 is
configured as a recess in the fluid outlet surface 125. The outlet
manifold 132 is defined by an outlet manifold wall 134. The
plurality of jet orifices 127 of each of the first jet region 123a
and the second jet region 123b extend fully through the manifold
120 and are positioned within the outlet manifold 132. The fluid
outlet surface 125 further includes a gasket groove 131 to receive
a gasket (not shown) for sealing the fluid outlet surface with
respect to the target plate 140,
[0041] A fluid outlet 130 extends fully through the manifold 120
and is fluidly coupled to the outlet manifold 132. Referring
briefly to FIG. 2, the fluid outlet 130 is fluidly isolated from
the fluid inlet channel 122, the first jet region 123a, and the
second jet region 123b.
[0042] The fluid outlet 130 is disposed between a first wall 134a
and a second wall 134b (each a portion of the collective outlet
manifold wall 134). In the illustrated embodiment, the first wall
134a and the second wall 134b are angled outwardly away from a
central region of the outlet manifold 132 by an angle .theta. with
respect to line B that is parallel to edge 137 of the manifold 120.
The angled first wall 134a and second wall 134b may assist in
directing cooling fluid toward the fluid outlet 130 so that it may
exit the cooling device 100 through the outlet port 112.
[0043] Referring once again to FIG. 2, the target plate 140 is
coupled to the fluid outlet surface of the manifold 120. The target
plate 140 has a target surface 141 that receives the impingent jets
of cooling fluid and a heat receiving surface 142 at which one or
more heat generating devices are coupled. The target plate 140 is
fabricated from a thermally conductive material such as, without
limitation, aluminum and copper.
[0044] The example target plate 140 depicted in FIG. 2 comprises a
first array of pin-fins 143a (i.e., a first heat sink) and a second
array of pin-fins 143b (i.e., a second heat sink) extending from
the target surface 141. When the cooling device 100 is assembled,
the first array of pins fins 143a is aligned with the plurality of
jet orifices 127 of the first jet region 123a and the second array
of pins fins 143b is aligned with the plurality of jet orifices 127
of the second jet region 123b. In this manner, impingement jets of
cooling fluid from the pluralities of jet orifices 127 impingement
the target surface 141 at the first array of pin-fins 143a and the
second array of pin-fins 143b.
[0045] Referring now to FIGS. 5A and 5B, a top view and a side view
of an array of pin-fins 143 are schematically depicted (i.e., a
pin-fin heat sink). Each pin-fin 145 is configured as a feature,
such as a pillar, that extends from the target surface 141 of the
target plate 140. The pin-fin 145 may take on any shape in
cross-section, such as rectangular, circular, elliptical, or the
like. The pin-fins 145 are separated from one another by a gap 146.
The size of the pin-fins 145 and the size of the gap 146 are not
limited by this disclosure. In embodiments, the top of the pin-fins
145 may contact the fluid outlet surface 125 of the manifold
120.
[0046] As shown in FIG. 5B, a heat generating device 150 is
thermally coupled to the heat receiving surface 142 of the target
plate 140 opposite from the array of pin-fins 143 (e.g., by
transient liquid phase bonding, brazing, solder, or the like). The
heat generating device 150 may be any component that generates
heat. As a non-limiting example, the heat generating device 150 may
be an electronic device, such as a power semiconductor device.
Power semiconductor devices may include, without limitation,
insulated-gate bi-polar transistors, metal-oxide field-effect
transistors, and bi-polar transistors. In some embodiments, the
heat generating device(s) may be silicon carbide devices, which
operate at relatively high operating temperatures (e.g., greater
than 200.degree. C.). As a further non-limiting example, the
cooling devices described herein may be implemented in an inverter
circuit in an electric or hybrid-electric vehicle to cool power
semiconductors by two-phase and jet-impingement cooling. The
combination of a cooling device 100 and one or more power
electronic devices 150 is referred to herein as an electronic
device assembly.
[0047] Heat generated by the heat generating device 150 passes
through the target plate 140 and the array of pin-fins 143, where
it is transferred to the cooling fluid as the impingement jets
strike the array of pin-fins 143. The array of pin-fins 143
increases the surface area of contact with the cooling fluid,
thereby increasing heat transfer from the target plate 140 to the
cooling fluid. At high heat fluxes, nucleate boiling occurs on the
target surface 141 and the array of pin-fins 143 creating areas of
two-phase heat transfer. In some embodiments, the target surface
141 and/or the array of pin-fins 143 has a porous surface to
enhance nucleation of the cooling fluid. The porous surfaces may be
provided by a porous coating, for example, which may be made of
copper, aluminum or any other thermally conductive materials. In
some embodiments, the porous surface is provided by chemically
etching the surfaces of the target surface 141 and/or the array of
pin-fins 143.
[0048] Embodiments described herein are not limited to pinned heat
sinks as illustrated in FIGS. 2, 5A and 5B. FIGS. 6A and 6B depict
a portion of an example target plate 140' having another example
heat sink 144. FIG. 6A is a top-down view of the example heat sink
144 on the target plate 140', while FIG. 6B is a side elevation
view of the same. The example heat sink 144 has one or more walls
145 that define a central impingement region 147. Although the
example heat sink 144 is depicted as having four walls 145
providing a square-shaped central impingement region 147,
embodiments are not limited thereto. For example, the one or more
walls may provide for a central impingement region 147 having a
circular shape, an elliptical shape, a triangular shape, or other
shape.
[0049] One or more heat generating devices 150 are thermally
coupled to a heat receiving surface 142 of the target plate 140'
opposite the one or more heat sinks 144. One or more heat sinks 144
are positioned on the target plate 140' (e.g., two heat sinks) such
that the one or more heat sinks 144 are aligned with one or more
arrays of jet orifices 127 of the manifold 120. Accordingly,
impingement jets of cooling fluid strike the central impingement
region 147. In embodiments, an upper surface 148 of the one or more
walls 145 contacts the fluid outlet surface 125 of the manifold 120
to confine the cooling fluid within the central impingement region
147 after impingement. This confinement of the cooling fluid within
the central impingement region 147 may promote the phase change of
the cooling fluid from a liquid to a vapor in response to heat flux
provided by the heat generating device.
[0050] The example heat sink 144 shown in FIGS. 6A and 6B further
includes open channels 149 positioned within the one or more walls
145. The channels 149 of the illustrated embodiment are configured
as grooves through the one or more walls 145. Cooling fluid, in
vapor and/or liquid form, efficiently exits the central impingement
region 147 through the open channels 149.
[0051] As stated above with respect to the pin-fin heat sinks 143,
the heat sink 144 depicted in FIGS. 6A and 6B may be smooth or have
a porous surface to promote nucleate boiling of the cooling fluid.
The porous surface may be provided by a coating, an etching
process, or any other process or material. It should be noted that
the heat sink 144 may be made of any thermally conductive material,
such as copper or aluminum, for example.
[0052] FIGS. 7A and 7B depict a partial view of another example
target plate 140'' comprising one or more heat sinks 144'. FIG. 7A
is a top-down view of the example heat sink 144' on the target
plate 140'', while FIG. 7B is a side elevation view of the same.
The example heat sink 144' has one or more walls 145' that define a
central impingement region 147. Although the example heat sink 144'
is depicted as having four walls 145' providing a square shaped
central impingement region 147, embodiments are not limited
thereto. For example, the one or more walls may provide for a
central impingement region 147 having a circular shape, an
elliptical shape, a triangular shape, or other shape.
[0053] As stated above with respect to FIGS. 6A and 6B, one or more
heat generating devices 150 are thermally coupled to a heat
receiving surface 142' of the target plate 140''opposite the one or
more heat sinks 144'. One or more heat sinks 144' are positioned on
the target plate 140'' (e.g., two heat sinks) such that the one or
more heat sinks 144' are aligned with one or more arrays of jet
orifices 127 of the manifold 120. Accordingly, impingement jets of
cooling fluid strike the central impingement region 147. In
embodiments, an upper surface 148' of the one or more walls 145'
contacts the fluid outlet surface 125 of the manifold 120 to
confine the cooling fluid within the central impingement region 147
after impingement. This confinement of the cooling fluid within the
central impingement region 147 may promote the phase change of the
cooling fluid from a liquid to a vapor in response to heat flux
provided by the heat generating device 150.
[0054] The example heat sink 144' shown in FIGS. 7A and 7B further
includes closed channels 149' positioned within the one or more
walls 145'. The channels 149' of the illustrated embodiment are
configured as bores (i.e., through holes) positioned through the
one or more walls 145'. Cooling fluid, in vapor and/or liquid form,
efficiently exits the central impingement region 147 through the
closed channels 149'.
[0055] As stated above with respect to the heat sink 144 depicted
in FIGS. 6A and 6B, the heat sink 144' depicted in FIGS. 7A and 7B
may be smooth or have a porous surface to promote nucleate boiling
of the cooling fluid. The porous surface may be provided by a
coating, an etching process, or any other process or material. It
should be noted that the heat sink 144' may be made of any
thermally conductive material, such as copper or aluminum, for
example.
[0056] The effect of heat flux with respect to the heat transfer
coefficient and pressure drop for three cooling devices as shown in
FIGS. 1 and 2 were evaluated by computer simulation. One simulated
cooling device included two pin-fin heat sinks 143 (see FIGS. 5A
and 5B), another simulated cooling device included two open channel
heat sinks 144 (see FIGS. 6A and 6B), and another simulated cooling
device included two closed channel heat sink 144' (see FIGS. 7A and
7B).
[0057] FIG. 8 graphically depicts the heat transfer coefficient
between the three types of heat sinks using R-245fa as the cooling
fluid. The inlet temperature of the cooling fluid was 40.degree. C.
except where noted. It is noted that the pin-fin heat sinks did not
reach critical heat flux.
[0058] FIG. 9 graphically depicts the pressure drop within the
simulated cooling devices including the three different types of
heat sinks. The cooling fluid was R-245fa. The inlet temperature of
the cooling fluid was 40.degree. C. except where noted.
[0059] Referring to FIGS. 1 and 10, operation of an example cooling
device 100 will now be described. Cooling fluid is introduced into
the cooling device 100 by way of the inlet port 115. Any suitable
cooling fluid may be utilized. Non-limiting cooling fluids include
water, refrigerants, and dielectric cooling fluids. Non-limiting
dielectric cooling fluids include R-245fa and HFE-7100. Other
cooling fluids may be utilized. The type of cooling fluid chosen
may depend on the operating temperature of the heat generating
device 150 to be cooled. The inlet temperature of the cooling fluid
may be regulated by one or more components upstream from the
cooling device 100.
[0060] Referring now to FIG. 10, the coolant fluid enters the inlet
channel 122 at the fluid inlet surface 121 of the manifold 120 as
indicated by arrow 160. The cooling fluid travels through the inlet
channel 122 as indicated by arrows 161, where it is then redirected
into the first jet region 123a and the second jet region 123b by
the protrusion 133 of the perimeter wall 128. The cooling fluid
flows through the first jet region 123a and the second jet region
123b as indicated by arrows 162a and 162b. The shape of the
perimeter wall 128 and the shape and position of the surface
features 126 optimally route the cooling fluid toward the jet
orifices 127 such that there is substantially uniform fluid flow
through each jet orifice 127 within the first and second jet
regions 123a, 123b. As used herein, the term "substantially uniform
fluid flow" means that the fluid flow is within 10% of a
theoretical calculated fluid flow for a majority of the jet
orifices 127 of the cooling device 100.
[0061] Referring now to FIGS. 2 and 11, the coolant fluid exits the
jet orifices 127 as impingement jets that strike the target plate
140 at a heat sink 143. Heat flux created by the heat generating
devices 150 coupled to the heat receiving surface 142 of the target
plate 140 heats the cooling fluid such that it changes from a
liquid to a vapor. Porous surfaces may be provided to provide
additional nucleation sites to enhance nucleate boiling of the
cooling fluid. Cooling fluid, in the form of vapor, exits the heat
sink area and flows toward the fluid outlet 130 as indicated by
arrows 163A, 163B. Walls 134a and 134b assist in directing the
vapor toward the fluid outlet 130, where it then exits the cooling
device 100 through the outlet port 112 (arrow 164).
[0062] It should now be understood that embodiments described
herein are directed to two phase jet impingement, cooling devices
for cooling heat generating devices, such as power semiconductor
devices. A symmetrical inlet manifold having two jet orifice
regions with an optimized perimeter wall and surface features
ensure substantially uniform fluid flow through each impingement
jet with minimal pressure drop. The target surface includes heat
sinks that promote phase change of the cooling fluid from a liquid
to a vapor. In embodiments, the target surface and/or the heat
sinks are porous to provide additional nucleation sites.
[0063] While particular embodiments have been illustrated and
described herein, it should be understood that various other
changes and modifications may be made without departing from the
spirit and scope of the claimed subject matter. Moreover, although
various aspects of the claimed subject matter have been described
herein, such aspects need not be utilized in combination. It is
therefore intended that the appended claims cover all such changes
and modifications that are within the scope of the claimed subject
matter.
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