U.S. patent application number 09/775073 was filed with the patent office on 2002-08-01 for metal hydride storage apparatus.
Invention is credited to Zuo, Jon.
Application Number | 20020100288 09/775073 |
Document ID | / |
Family ID | 25103238 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020100288 |
Kind Code |
A1 |
Zuo, Jon |
August 1, 2002 |
Metal hydride storage apparatus
Abstract
The present invention relates to a miniature metal hydride
thermal storage apparatus for the cooling of devices to subambient
temperatures, the apparatus composed of at least two chambers
containing distinct metal hydrides.
Inventors: |
Zuo, Jon; (Lancaster,
PA) |
Correspondence
Address: |
Samuel W. Apicelli, Esquire
DUANE, MORRIS & HECKSCHER LLP
305 North Front Street
P.O. Box 1003
Harrisburg
PA
17108-1003
US
|
Family ID: |
25103238 |
Appl. No.: |
09/775073 |
Filed: |
February 1, 2001 |
Current U.S.
Class: |
62/259.2 ;
257/E23.101; 62/480 |
Current CPC
Class: |
F17C 11/005 20130101;
Y02E 60/324 20130101; Y02E 60/32 20130101; H01L 23/36 20130101;
H01L 2924/0002 20130101; C09K 5/16 20130101; F25B 17/12 20130101;
C01B 3/0005 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
62/259.2 ;
62/480 |
International
Class: |
F25B 017/08 |
Claims
What is claimed is:
1. A miniature metal hydride thermal storage apparatus, which
provides for the cooling of devices to subambient temperatures, the
apparatus comprising at least two chambers containing distinct
metal hydrides.
2. The apparatus as recited in claim 1, wherein the devices include
laptop computers, cellular phones, other mobile electronics and
consumer products.
3. The apparatus as recited in claim 1, wherein the subambient
temperatures are no lower than -10.degree. C.
4. The apparatus as recited in claim 1, wherein the metal hydride
is selected from the group consisting of lanthanum nickel metal
alloy and magnesium nickel metal alloy.
5. The apparatus as recited in claim 1, wherein each chamber
contains a distinct metal hydride.
6. The apparatus as recited in claim 1, wherein the metal hydride
is combined with high conductance metal powders.
7. The apparatus as recited in claim 6, wherein said combination
promotes heat conduction in the porous structure.
8. The apparatus as recited in claim 1, wherein the conducting
powders are selected from the group consisting of copper, aluminum
and silicon powders.
9. The apparatus as recited in claim 8, wherein hydrogen passages
are formed in the metal hydride powder structures by mandrels.
10. The apparatus as recited in claim 1, further comprising a
miniature valve.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a miniature metal hydride
thermal storage cartridge for the cooling of devices to subambient
temperatures, the cartridge composed of two chambers containing two
different metal hydrides.
BACKGROUND OF THE INVENTION
[0002] In recent years, the storage of hydrogen as a potential fuel
or reactant has become of increasing interest and numerous systems
have been described whereby hydrogen can be stored as an
interstitial hydride or stoichiometric compound of an appropriate
metal, to be released as required, the storage systems being
reversible.
[0003] One of these systems utilizes magnesium (Mg) which can form
the hydride (MgH.sub.2) from which hydrogen can be driven in
gaseous form. A storage system based upon the reversible reaction
H.sub.2+Mg+MgH.sub.2 is thus capable of storing hydrogen from a
gaseous state upon contact of the hydrogen with the metal and of
releasing hydrogen in a gaseous form at a subsequent time and, if
desired, at a different place.
[0004] While a number of other materials have also been proposed
for the storage of hydrogen in the form of respective hydrides,
magnesium has been found to be of interest because of its
relatively low cost and light weight which allows for a theoretical
capacity of 7.6% by weight of hydrogen (based upon the weight of
metal) to be stored and regenerated.
[0005] The storage of hydrogen in the form of magnesium hydride is
described, for example, in French Pat. No. 1,529,371 and British
Pat. No. 1,171,364. The use of the Mg/MgH.sub.2 system for the
reversible storage of hydrogen on an industrial scale, however,
poses several practical problems.
[0006] For example, the magnesium should be in the form of a powder
so as to obtain the maximum specific surface area for hydrogen
absorption and hence the conversion of the Mg to MgH.sub.2 under
acceptable conditions.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a
miniature metal hydride thermal storage cartridge for the cooling
of devices, e.g., laptop computer chips, to subambient
temperatures, the cartridge composed of at least two chambers
containing different metal hydrides. The chambers may be connected
by a "miniature" valve to control the H.sub.2 flow between the
chambers. The metal hydride in each chamber may be formed into a
porous structure with multiple hydrogen (H.sub.2) channels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other objects, features and advantages of the
present invention will become apparent from a consideration of the
following detailed description presented in connection with the
accompanying drawings in which:
[0009] FIG. 1 displays a metal hydride thermal storage device in
conjunction with a set of heat sinks for subambient chip
cooling.
[0010] FIG. 2 displays a particular design of the metal hydride
thermal storage cartridge for subambient chip cooling.
[0011] FIG. 3 displays a metal hydride thermal storage cartridge
inserted into a battery charger for regeneration.
[0012] FIG. 4 displays an alternative hydride structure design.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The present invention relates to a miniature metal hydride
thermal storage cartridge for the cooling of laptop computer chips
and other mobile electronic consumer devices (e.g., cell phones,
mobile cold storage for campers) to subambient temperatures, the
cartridge composed of at least two chambers containing different
metal hydrides. FIG. 1 shows a design of a miniature metal hydride
thermal storage cartridge 10 for cooling of laptop computer chips
to subambient temperatures. The cartridge 10 includes two chambers
21 and 22 containing two different metal hydrides, lanthanum nickel
metal alloy 23 and magnesium nickel metal alloy 24, as shown in
FIG. 2. The two chambers 21 and 22 are connected by an on/off
miniature valve 25 that may be activated by the motion of inserting
the cartridges 10 or 27 into the main and supplemental heat sinks
28 and 29, as shown in FIG. 1. The chambers and valve form a
seamless, cylindrical outer surface, which provides effective
contact between the cartridges 10 and 27 and the heat sinks 28 and
29.
[0014] As shown in FIG. 2, prior to utilization of the apparatus of
the present invention, all hydrogen should be inside the chamber
that has a low-temperature metal hydride, e.g., the magnesium
nickel metal alloy chamber 21, and the valve 25 should be closed.
Upon inserting the cartridge 10 into the heat sinks 28 and 29, the
valve 25 is open, and the hydrogen begins disassociation with the
magnesium nickel metal alloy 23 and flows into the lanthanum nickel
metal alloy 24 in chamber 22. The two chambers 21 and 22 will reach
internal pressure balance when the magnesium nickel metal alloy and
lanthanum nickel metal alloy chambers 21 and 22 reach -10.degree.
C. and 70.degree. C., respectively. As a result of this process,
the cartridge 10 cools the chip 30 to subambient temperatures
(e.g., -10.degree. C.), and dissipates the heat (at, e.g.,
70.degree. C.) to ambient through the supplemental heat sink 29, as
shown in FIG. 1.
[0015] The effective time of use for a particular cartridge depends
on both the mass of the metal hydrides inside the cartridge, as
well as the cooling requirement. For instance, a chamber of 0.25
inches in diameter and 3 inches long is capable of storing
approximately 20 grams of metal hydrides and 0.4 grams of hydrogen.
Therefore, the chamber is capable of storing approximately 6,000
joules of thermal energy, assuming the metal hydride has an
enthalpy change of hydriding reaction of about 6 kcal/mole-H.sub.2.
This is equivalent to 10 watts of subambient cooling for ten
minutes. In a preferred embodiment of the present invention, a
combination of four cartridges will provide effective cooling for
an extended period of time (about 40 minutes) where "super
computing performance" is required. In this case, the total amount
of hydrogen inside the four cartridges is approximately 1.6
grams.
[0016] The cartridge 10 may be "recharged" by inserting the
lanthanum nickel metal alloy end into a hot socket 40, in order to
drive all of the hydrogen into the magnesium nickel metal alloy
chamber for furture use. This can be done along with recharging the
battery 41 in a battery charger 42, as shown in FIG. 3. An added
benefit is the cooling of the battery charger 42 by the H.sub.2
disassociation in the lanthanum nickel metal hydride chamber.
[0017] In a further preferred embodiment of the present invention,
as shown in FIG. 4, the metal hydride powders are "glued" together
and to the chamber inner walls using e.g., silicone. FIG. 4 shows a
cross section of chamber 10 containing metal hydrides 43. The
H.sub.2 passages 44 may be formed by e.g., mandrels during the
"gluing" process. In order to improve the heat conduction of the
powder matrix, an effective amount of high conductance metal (e.g.,
Cu, Si) powders may be mixed with the metal hydride powders before
being glued together. Such powders are inert in a hydrogen
environment; the powders enhance effective thermal conductivity of
the porous structure.
[0018] Thus, a preferred embodiment of the present invention
employs the use of two different metal hydrides to achieve
subambient cooling of electronic devices, e.g., laptop computers,
mobile phones and other consumer electronic equipment. The
cartridge-type thermal storage device may be recharged along with
batteries. The metal hydrides may be mixed with e.g., copper
powder, to improve thermal conductivity. In an alternative hydride
bonding design, mandrel-formed H.sub.2 passages in a packed metal
hydride powder structure may also achieve the purposes of the
present invention.
[0019] While this invention has been described with respect to
particular embodiments thereof, it is apparent that numerous other
forms and modifications of this invention will be obvious to those
skilled in the art. The appended claims and this invention
generally should be construed to cover all such obvious forms and
modifications which are within the true spirit and scope of the
present invention.
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