U.S. patent application number 14/949010 was filed with the patent office on 2017-05-25 for evaporator assembly.
This patent application is currently assigned to L-3 Communications Corporation. The applicant listed for this patent is L-3 Communications Corporation. Invention is credited to John Michael RODGERS, Matthew J. SPITZNER, Richard M. WEBER.
Application Number | 20170146273 14/949010 |
Document ID | / |
Family ID | 56851359 |
Filed Date | 2017-05-25 |
United States Patent
Application |
20170146273 |
Kind Code |
A1 |
SPITZNER; Matthew J. ; et
al. |
May 25, 2017 |
Evaporator Assembly
Abstract
An evaporator apparatus comprising a liquid distribution chamber
and a vapor production chamber. The vapor production chamber
comprises a media wick that absorbs heat from a source external to
the vapor production chamber. The vapor production chamber is
configured to receive liquid coolant from the liquid distribution
chamber and to direct the received liquid coolant onto a surface of
the media wick. The media wick distributes the received liquid
coolant from the surface of the media wick throughout a body of the
media wick. The heat absorbed by the media wick vaporizes the
liquid coolant distributed throughout the body of the media wick.
The coolant vapor flows from the media wick into the vapor
production chamber.
Inventors: |
SPITZNER; Matthew J.; (Lowry
Crossing, TX) ; RODGERS; John Michael; (Farmers
Branch, TX) ; WEBER; Richard M.; (Prosper,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
L-3 Communications Corporation |
New York |
NY |
US |
|
|
Assignee: |
L-3 Communications
Corporation
New York
NY
|
Family ID: |
56851359 |
Appl. No.: |
14/949010 |
Filed: |
November 23, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 39/02 20130101;
F28D 15/04 20130101; F28D 15/0266 20130101; F25B 39/00 20130101;
F28D 15/046 20130101; F28F 13/187 20130101; H05K 7/20336 20130101;
H01L 23/4735 20130101; H01L 23/427 20130101 |
International
Class: |
F25B 39/00 20060101
F25B039/00 |
Claims
1. An evaporator apparatus comprising: a liquid distribution
chamber; and a vapor production chamber comprising a media wick
that absorbs heat from a source external to the vapor production
chamber, wherein the vapor production chamber is configured to
receive liquid coolant from the liquid distribution chamber and to
direct the received liquid coolant onto a surface of the media
wick.
2. The evaporator apparatus as set forth in claim 1, wherein the
media wick distributes the received liquid coolant from the surface
of the media wick throughout a body of the media wick.
3. The evaporator apparatus as set forth in claim 2, wherein the
heat absorbed by the media wick vaporizes the liquid coolant
distributed throughout the body of the media wick and wherein the
coolant vapor flows from the media wick back into the vapor
production chamber.
4. The evaporator apparatus as set forth in claim 1, wherein the
media wick is fused to an exterior wall of the vapor production
chamber.
5. The evaporator apparatus as set forth in claim 1, wherein the
media wick comprises sintered copper microballs.
6. The evaporator apparatus as set forth in claim 1, wherein the
media wick comprises a porous material that uses capillary action
to distribute the received liquid coolant from the surface of the
media wick throughout a body of the media wick.
7. The evaporator apparatus as set forth in claim 6, wherein the
heat absorbed by the media wick vaporizes the liquid coolant
distributed throughout the body of the media wick and wherein the
coolant vapor flows from the media wick into the vapor production
chamber.
8. The evaporator apparatus as set forth in claim 6, wherein the
media wick is fused to an exterior wall of the vapor production
chamber.
9. The evaporator apparatus as set forth in claim 6, wherein the
media wick comprises sintered copper microballs.
10. The evaporator apparatus as set forth in claim 1, further
comprising a plurality of nozzles disposed in a common wall
separating the liquid distribution chamber and the vapor production
chamber, wherein the plurality of nozzles are configured to
transport the liquid coolant from the liquid distribution chamber
into the vapor production chamber and to direct the liquid coolant
onto the surface of the media wick.
11. The evaporator apparatus as set forth in claim 1, wherein the
liquid distribution chamber receives the liquid coolant from an
external supply and is configured to maintain a pressure of the
liquid coolant above the saturation pressure of the liquid coolant
at the highest temperature at which the evaporator apparatus is
expected to operate.
Description
TECHNICAL FIELD
[0001] The present application relates generally to cooling systems
and, more specifically, to a two-phase evaporator assembly that
transports away from a surface.
BACKGROUND
[0002] Many industrial systems, mechanical apparatuses, electronic
systems, and vehicles produce large amounts of waste heat. For
example, high performance computers and servers with a large number
of similar electronic devices produce a large amount of waste heat.
It is necessary to remove this waste heat from the system in order
to prevent damage to the electronic components due to overheating
and to ensure performance.
[0003] One conventional system for removing heat is a two-phase
evaporator. Ideally, a two-phase evaporator provides a near uniform
flow of coolant over the surface of the evaporator so that similar
devices see very similar thermal impedances. Otherwise, there could
be excessive temperature differences between similar devices. Also,
the evaporator should be able to supply the coolant to the
evaporating surface regardless of the orientation of the
evaporator. The evaporator should also ensure proper coolant
distribution without "flashing" of the coolant within the
evaporator distribution system
[0004] Therefore, there is a need in the art for an improved
cooling apparatus for removing waste heat from a heat-producing
system.
SUMMARY
[0005] To address the above-discussed deficiencies of the prior
art, it is a primary object to provide a two-phase evaporator to
provide cooling to a heat-producing system. The disclosed two-phase
evaporator comprises heat load of near uniform heat flux over the
surface of the evaporator. At the same time, the disclosed
two-phase evaporator has all portions of the surface of the
evaporator at essentially the same operating temperature. The
evaporator may use coolants such as water, methanol, or a
fluorocarbon-based fluid (e.g., Fluorinert.RTM.), wherein heat is
absorbed as these coolants go through a phase change from a liquid
phase to a gas or vapor phase.
[0006] It is a primary object to provide an evaporator apparatus
comprising: 1) a liquid distribution chamber; and 2) a vapor
production chamber comprising a media wick that absorbs heat from a
source external to the vapor production chamber. The vapor
production chamber is configured to receive liquid coolant from the
liquid distribution chamber and to direct the received liquid
coolant onto a surface of the media wick.
[0007] In one embodiment of the disclosure, the media wick
distributes the received liquid coolant from the surface of the
media wick throughout a body of the media wick.
[0008] In another embodiment, the heat absorbed by the media wick
vaporizes the liquid coolant distributed throughout the body of the
media wick and wherein the coolant vapor flows from the media wick
into the vapor production chamber.
[0009] In still another embodiment, the media wick is fused to an
exterior wall of the vapor production chamber.
[0010] In yet another embodiment, the media wick comprises sintered
copper microballs.
[0011] In a further embodiment of the disclosure, the media wick
comprises a porous material that uses capillary action to
distribute the received liquid coolant from the surface of the
media wick throughout a body of the media wick.
[0012] In a still further embodiment, the evaporator apparatus
further comprises a plurality of nozzles disposed in a common wall
separating the liquid distribution chamber and the vapor production
chamber. The plurality of nozzles are configured to transport the
liquid coolant from the liquid distribution chamber into the vapor
production chamber and to direct the liquid coolant onto the
surface of the media wick.
[0013] In a yet further embodiment, the liquid distribution chamber
receives the liquid coolant from an external supply and is
configured to maintain a pressure of the liquid coolant above the
saturation pressure of the liquid coolant at the highest
temperature at which the evaporator apparatus is expected to
operate.
[0014] Before undertaking the DETAILED DESCRIPTION below, it may be
advantageous to set forth definitions of certain words and phrases
used throughout this patent document: the terms "include" and
"comprise," as well as derivatives thereof, mean inclusion without
limitation; the term "or," is inclusive, meaning and/or; the
phrases "associated with" and "associated therewith," as well as
derivatives thereof, may mean to include, be included within,
interconnect with, contain, be contained within, connect to or
with, couple to or with, be communicable with, cooperate with,
interleave, juxtapose, be proximate to, be bound to or with, have,
have a property of, or the like. Definitions for certain words and
phrases are provided throughout this patent document, those of
ordinary skill in the art should understand that in many, if not
most instances, such definitions apply to prior, as well as future
uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the present disclosure
and its advantages, reference is now made to the following
description taken in conjunction with the accompanying drawings, in
which like reference numerals represent like parts:
[0016] FIG. 1 illustrates a two-phase evaporator according to one
embodiment of the disclosure.
[0017] FIG. 2 illustrates a two-phase evaporator in greater detail
according to one embodiment of the disclosure.
DETAILED DESCRIPTION
[0018] FIGS. 1 through 2, discussed below, and the various
embodiments used to describe the principles of the present
disclosure in this patent document are by way of illustration only
and should not be construed in any way to limit the scope of the
disclosure. Those skilled in the art will understand that the
principles of the present disclosure may be implemented in any
suitably arranged evaporator assembly.
[0019] FIG. 1 illustrates two-phase evaporator 100 according to one
embodiment of the disclosure. Evaporator 100 comprises coolant
supply 110, and evaporator assembly 120. Evaporator assembly 120
comprises a liquid distribution chamber 130 and a vapor production
chamber 140. Coolant is injected under pressure from the coolant
supply 110 into liquid distribution chamber 130. During operation,
the coolant pressure into and within liquid distribution chamber
130 is greater that than the highest anticipated saturation
pressure of the coolant. Exemplary coolants may be water, methanol,
or a fluorocarbon-based fluid (e.g., Fluorinert.RTM.). At the exit
of vapor production chamber 140, the vapor stream may be condensed
using a heat exchanger and re-circulated as part of a closed-loop
system or may be vented as part of an open-loop system.
[0020] FIG. 2 illustrates two-phase evaporator assembly 120 in
greater detail according to one embodiment of the disclosure.
Evaporator assembly 120 comprises liquid distribution chamber 130
and vapor production chamber 140, as noted in FIG. 1. The walls of
liquid distribution chamber 130 form liquid distribution cavity
205. Coolant inlet 206 brings liquid coolant from coolant supply
110 into liquid distribution cavity 205. The walls of vapor
production chamber 140 form vapor production cavity 210. Vapor
outlet 211 removes vapor from vapor production cavity 210 to an
external vent (open loop system) or a condenser (closed loop
system).
[0021] Wall 250 separates the cavities of liquid distribution
chamber 130 and vapor production chamber 140. Vapor production
chamber 140 contains porous media wick 220, which is formed (e.g.,
fused) against the inner surface of exterior wall 230 of vapor
production chamber 140. The outer surface of exterior wall 230
receives the waste heat (thermal energy) that must be
eliminated.
[0022] A plurality of jetting nozzles, including exemplary nozzles
241, 242 and 243, among others, inject liquid coolant under
pressure into vapor production cavity 210 and onto inner surface
221 of media wick 220. The coolant that impinges on surface 221 is
absorbed into media wick 220 (shaded area). According to the
principals of the present disclosure, media wick 220 is a porous
and dense material that exhibits high capillary action pressure
(local spreading) that absorbs the impinged liquid coolant and
distributes the absorbed liquid coolant uniformly throughout the
body (shaded area) of media wick 220. By way of example, media wick
220 may comprise sintered copper micro-balls (or a similar device),
similar to the wick inside of a heat pipe.
[0023] In FIG. 2, the pressure of the liquid coolant that fills
liquid distribution cavity 205 is kept high to increase the boiling
point of the liquid coolant. Thus, the fluid manifold pressure is
maintained greater than the highest anticipated saturation pressure
(P.sub.saturation) of the liquid coolant so that the coolant
remains in a fluid state in liquid distribution chamber 205 and as
it is injected through exemplary nozzles 241, 242, and 243.
[0024] Jet nozzles 241, 242, and 243 are evenly distributed and
closely spaced (e.g., 1/8 inch to 3/8 inch) to ensure a uniform
distribution of liquid coolant onto surface 221 of media wick 220.
In FIG. 2, the dotted line arrows pointing from left to right
indicate sprays of liquid coolant leaving nozzles 241, nozzle 242,
and nozzle 243 and impinging on surface 221 of media wick. The
array of jet nozzles sprays coolant onto the porous media wick 220,
which captures the liquid coolant and transports it small distances
using capillary action. The dotted line curved arrows within the
body of media wick 220 indicate the internal distribution of the
liquid coolant via capillary action. Jetting streams of liquid
coolant flow through the orifices of nozzles 241, 242, 243, with
sufficient pressure drop at required flow rates to ensure an
upstream pressure that is above the worst-case saturation pressure
of the coolant.
[0025] Media wick 220 has sufficient thickness and capillary
pressure to transport the coolant with sufficient flow rate from
the jetting impact sites to all portions of the internal, porous
structure of media wick 220. The jetting spay provides wide area,
near uniform coolant distribution of liquid coolant into the lower
pressure vapor production cavity 210.
[0026] The waste heat that impinges on wall 230 enters media wick
220 and heats and vaporizes the liquid coolant as the liquid
coolant is distributed closer to outer wall 230. The vaporized
coolant is forced from media wick 220 into vapor production cavity
210. The solid line curved arrows pointing from right to left
indicate vaporized coolant leaving the body of media wick 220 and
entering vapor production cavity 210. The vaporized coolant then
exits vapor production cavity 210 via outlet 211.
[0027] The present disclosure describes an evaporator that uses an
array of multiple, jetting streams of a coolant to ensure even
distribution onto a porous, wicking media, which is fused to the
inner surface of a wall of the evaporator assembly. The wicking
media transports the coolant from liquid jet impact sites into
areas in the body of the wicking media, where waste heat from
components mounted on the opposing outer surface of the wall is
absorbed as the coolant changes from a liquid to a vapor. The
jetting streams flow through restricting orifices to ensure the
pressure of the coolant in its supply manifold is above the
saturation pressure of the coolant at the highest temperature of
the supplied coolant that will be seen in operation. This ensures
that only liquid is distributed by the array of jetting
streams.
[0028] The disclosed two-phase evaporator provides a near uniform
flow of coolant over the surface of the evaporator to minimize
excessive temperature differences between similar devices, such as
electronic processors or amplifiers. The disclosed two-phase
evaporator supplies the coolant to the evaporating surface
regardless of the orientation of the evaporator and ensures proper
coolant distribution without "flashing" of the coolant within the
distribution system of the evaporator.
[0029] Although the present disclosure has been described with an
exemplary embodiment, various changes and modifications may be
suggested to one skilled in the art. It is intended that the
present disclosure encompass such changes and modifications as fall
within the scope of the appended claims.
* * * * *