The present invention relates to hydrogen storage containers and, particularly, to containers for containing metallic particles capable of forming metal hydrides.
Metal hydrides, in the form of metallic particles, are used to store hydrogen in many different sizes and shaped containers. In order to facilitate the charging and discharging of the hydrogen, the metal hydride and, consequently, the container, needs to be cooled or heated. To facilitate good performance of the container (desorption rate, filling time, etc.), the inside of the container requires efficient heat exchange means to improve the charging/discharging kinetics.
Repeated absorption and desorption cycles typically result in the decrepitation of the metal hydride particles. By virtue of the decrepitation, a localized increase in packing fraction of the metallic particles is observed. Such increase in packing fraction, coupled with particle expansion during absorption, potentially creates localized stresses on the container. It is desirable to have means inside the container to absorb part of this volumetric expansion so that stress on the container is mitigated or avoided.
The present invention provides a container configured for containing metallic particles, the metallic particles capable of absorbing hydrogen such that the metallic particles expand upon the absorption of hydrogen, the container including an inner surface, comprising a liner disposed within the container such that a void space is provided between the liner and the inner surface, wherein the liner engages the inner surface to substantially prevent ingress of metallic particles, when the metallic particles are contained in the container, into the void space.
In another broad aspect, the present invention provides a container configured for containing at least metallic particles, the metallic particles capable of absorbing hydrogen such that the metallic particles expand upon the absorption of hydrogen, the container including a container space and an inner surface, comprising a liner disposed within the container space and engaging the inner surface for defining (i) a storage space configured to contain the metallic particles and (ii) a void space configured to contract as the metallic particles expand upon the absorption of hydrogen, wherein, when the metallic particles are contained in the storage space, the engagement of the liner to the inner surface limits ingress of the metallic particles into the void space from the storage space.
In a further broad aspect, the present invention provides a container configured for containing at least metallic particles and gaseous hydrogen, the metallic particles capable of absorbing hydrogen such that the metallic particles expand upon the absorption of hydrogen, the container including a container space and an inner surface, comprising a liner disposed within the container such that a void space is provided between the liner and the inner surface, wherein the liner engages the inner surface to limit ingress of metallic particles, when the metallic particles are contained in the container, into the void space.
In a further broad aspect, the present invention provides a container configured for containing at least gaseous hydrogen and metallic particles, the metallic particles capable of absorbing hydrogen such that the metallic particles expand upon the absorption of hydrogen, the container defining a container space and including an inner surface, comprising a liner disposed within the container space and engaging the inner surface for defining (i) a storage space configured to contain the metallic particles and (ii) a void space configured to contract as the metallic particles expand upon the absorption of hydrogen, wherein, when the metallic particles are contained in the storage space, the engagement of the liner to the inner surface substantially prevents ingress of the metallic particles into the void space from the storage space.
In one aspect, the present invention provides the container wherein the liner is sufficiently flexible to deform in response to the expansion of the metallic particles.
In another aspect, the present invention provides the container wherein the liner is shaped to define (i) a storage space configured to contain metallic particles and (ii) a void space configured to contract as the metallic particles expand upon the absorption of the hydrogen.
In yet another aspect, the present invention provides the container wherein the liner bears against the wall to substantially prevent or limit ingress of the metallic particles into the void space from the storage space when the storage space contains the metallic particles.
In a further aspect, the present invention provides the container wherein the liner abuts the wall to substantially prevent or limit ingress of the metallic particles into the void space from the storage space when the storage space contains the metallic particles.
In yet a further aspect, the present invention provides the container wherein the liner is urged against the wall to substantially prevent or limit ingress of the metallic particles into the void space from the storage space when the storage space contains the metallic particles.
In yet another aspect, the present invention provides the container wherein the liner is sufficiently resilient such that the liner has a tendency to reverse at least a portion of the deformation in response to discharging of hydrogen from the metallic particles.
In a further aspect, the present invention provides the container wherein the container includes a sidewall and an axis, the sidewall defining at least a portion of the inner surface and being spaced apart from and extending 360° about the axis in a plane, and wherein at least a portion of the liner is disposed between the sidewall and the axis and extends 360° about the axis in the plane.
In another aspect, the present invention provides the container wherein the at least a portion of the liner opposes the sidewall.
In yet another aspect, the present invention provides the container wherein at least a portion of the void space is disposed between the sidewall and the at least a portion of the liner.
In a further aspect, the present invention provides the container wherein each of the sidewall and the liner is substantially tubular.
In another aspect, the present invention provides the container wherein the liner includes corrugations defined by alternating ridges and grooves, each of the ridges and grooves extending transversely relative to the plane.
In yet a further aspect, the present invention provides the container wherein at least one of the ridges is configured to contact the sidewall when the metallic particles are contained in the storage space.
In another aspect, the present invention provides the container further comprising a thermally conductive structure disposed in the storage space and in contact with the liner and configured for effecting heat transfer between the metallic particles and the liner.
In another aspect, the present invention provides the container wherein the liner is stiffer than the container.
The present invention additionally provides a method of assembling a storage system for containing metallic particles capable of absorbing hydrogen to become charged with hydrogen comprising providing a container including an inlet and an inner surface defining a container space, inserting a magnetically responsive liner into the container space through the inlet, and applying a magnetic force sufficient to urge the liner against the inner surface of the container.
In another aspect, the present invention provides the method wherein the magnetic force is generated externally of the container.
In another aspect, the present invention provides the method wherein the liner being inserted into the container space has a spiral configuration, and the application of the magnetic force effects expansion of the liner from the spiral configuration.
In another aspect, the present invention provides the method further comprising the step of inserting a plurality of tubes into the container space through the inlet when the magnetic force is acting on the liner.
In another broad aspect, the present invention provides a method of assembling a container for containing metallic particles capable of absorbing hydrogen to become charged with hydrogen comprising providing a container including an inlet and an inner surface defining a container space, inserting a magnetically responsive liner into the container space through the inlet, applying a magnetic force sufficient to urge the liner against the inner surface of the container, when the magnetic force is acting on the liner, inserting a plurality of tubes into the container space through the inlet so as to urge the liner into engagement with the inner surface so as to define (i) a storage space configured to contain the metallic particles and (ii) a void space configured to contract as the metallic particles expand upon the absorption of hydrogen, and terminating the application of the magnetic force, and inserting a plurality of metallic particles into the storage space.
In this respect, in one aspect, the present invention provides the method wherein the magnetic force is generated externally of the container.
In another aspect, the present invention provides the method wherein the liner being inserted into the container space has a spiral configuration, and the application of the magnetic force effects expansion of the liner from the spiral configuration.
In yet another broad aspect, the present invention provides a method of assembling a container for containing metallic particles capable of absorbing hydrogen to become charged with hydrogen comprising providing a container including an inlet and an inner surface defining a container space, rolling a magnetically responsive liner about a mandrel so that the liner assumes a spiral configuration about the mandrel, when the liner is rolled about the mandrel, inserting the liner into the container space through the inlet, releasing the liner from the mandrel, removing the mandrel from the container space through the inlet, and applying a magnetic force sufficient to urge the liner against the inner surface of the container.
In another aspect, the present invention provides the method wherein the magnetic force is generated externally of the container.
In this respect, in one aspect, the present invention provides the method wherein the liner being inserted into the container space has a spiral configuration, and the application of the magnetic force effects expansion of the liner from the spiral configuration.
In another aspect, the present invention provides the method further comprising the step of inserting a plurality of tubes into the container space through the inlet when the magnetic force is acting on the liner.
The present invention also provides a method of assembling a container for containing metallic particles capable of absorbing hydrogen to become charged with hydrogen comprising providing a container including an inlet and an inner surface defining a container space, rolling a magnetically responsive liner about a mandrel so that the liner assumes a spiral configuration about the mandrel, when the liner is rolled about the mandrel inserting the liner into the container space through the inlet, releasing the liner from the mandrel, removing the mandrel from the container space through the inlet, applying a magnetic force sufficient to urge the liner against the inner surface of the container, when the magnetic force is acting on the liner, inserting a plurality of tubes into the container space through the inlet so as to urge the liner into engagement with the inner surface so as to define (i) a storage space configured to contain the metallic particles and (ii) a void space configured to contract as the metallic particles expand upon the absorption of hydrogen, terminating the application of the magnetic force, and inserting a plurality of metallic particles into the storage space.
In another aspect, the present invention provides the method wherein the magnetic force is generated externally of the container.
In another aspect, the present invention provides the method wherein the liner being inserted into the container space has a spiral configuration, and the application of the magnetic force effects expansion of the liner from the spiral configuration.
This invention will be better understood by reference to the following detailed description of the invention in conjunction with the following drawings, in which:
a and 4b are cross-sectional plan views of the container, taken along lines A-A and C-C, respectively, in
FIGS. 11 to 15 are schematic illustrations of a method of assembling an embodiment of the present invention;
b are cross-sectional plan views of another embodiment of the container, taken along lines A-A and C-C, respectively, in
Referring to
The interior space 20 of the container 10 receives metallic particles 12 capable of forming metal hydrides. The metallic particles 12 are in the form of a powder. An example of a suitable particle size of the powder is within the range of one micron to 3000 microns. The metallic particles 12 must be capable of absorbing hydrogen (also known as “charging”) to effect storage of hydrogen in the form of a metal hydride. Further, such metallic particles 12, after having absorbed hydrogen, (in the form of a metal hydride) must be capable of desorbing hydrogen (also known as “discharging”) upon demand from an unit operation, such as when required for use as a fuel in a fuel cell or in an internal combustion engine. Upon absorbing hydrogen, the metallic particles 12 expand, and thereby increase the volume occupied. During desorption, the metallic particles 12 contract, and thereby reduce the volume occupied. It is understood that not all of the metallic particles 12 must have necessarily absorbed hydrogen to their maximum capacity in order for the metallic particles 12 contained in the container 10 to be described as being “charged”. It is also understood that, once charged, not all of the previously absorbed hydrogen must have necessarily been desorbed in order for the metallic particles 12 contained in the container 10 to be described as being “discharged”. Charging of the metallic particles 12 with hydrogen is an exothermic process. In contrast, discharging of the absorbed hydrogen from the metallic particle 12 is an endothermic process.
Absorption of hydrogen by the metallic particles 12 refers to the association of hydrogen with the metallic particles 12. Possible mechanisms for association include: dissolution, covalent bonding, or ionic bonding. Dissolution describes the process where a hydrogen atom is incorporated in the voids of a lattice structure of a metal or intermetallic alloy. Examples of such metal hydrides include vanadium hydrides, titanium hydrides, and hydrides of vanadium-titanium alloys. An example of a covalently bonded hydride is magnesium hydride. Examples of ionically bonded hydrides are sodium hydride and potassium hydride. Complex hydrides are metal hydrides which exhibit bonding between a metalloid atom and an hydrogen atom which is characterized as being partially covalent and partially ionic. Examples include sodium alanate and lithium alanate.
The container 10 includes an inner surface 16 defining a container space 20 having a container volume. The inner surface 16 includes a first end 161, a second end 162, and a substantially tubular sidewall 163 extending between the first and second ends 161, 162 and also extending 360° about an axis 11 of the container. The first end 161 includes a rounded shoulder 169 extending from the sidewall 163 and terminating at a nozzle 24 which defines an aperture 241. The aperture 241 effects fluid communication between the container space 20 and the exterior of the container 10 (such as a downstream operation, for example, a fuel cell or internal combustion engine, so long as such unit operation is suitably fluidly coupled to the aperture 241). The aperture 241 functions as an inlet during charging, and as an outlet during discharging. Fluid communication through the aperture 241 is selectively controlled by a valve 300 coupled to the nozzle 24. The valve 300 is operable between open and closed conditions to respectively effect and seal the fluid communication. The second end 162 extends from the sidewall 163 and is closed.
A resilient liner 22 is disposed in the container 10. A void space 202 is provided between the liner and the inner surface 16 to accommodate expansion of the metallic particles 12 as is further described herein. Referring to
The liner 22 engages or abuts the inner surface 16 to define the void space 202 and limit ingress of the metallic particles 12 into the void space 202 from the storage space 201. In this respect, the liner 22 is urged into contact with (or bears against) the inner surface 16 to define the void space 202 and limit the above-described ingress into the void space 202. The first end 221 of the liner 22 bears against the second end 162 of the container, and a second end 222 of the liner 22 bears against the sidewall 163 or the shoulder 169, and thereby define the void space 202.
It is understood that the engagement or abutment of the liner 22 with the inner surface 16 does not necessarily completely prevent ingress of metallic particles 12 into the space between the liner 22 and the inner surface 16, although such ingress is prevented over discrete intervals of time. Ingress of very small quantities of the metallic particles 12 may occur as a result of the liner 22 becoming temporarily displaced from the inner surface 16, thereby providing a passage through which the metallic particles 12 can migrate into the void space 202 from the storage space 201. Relatively insignificant ingress may also occur in the case where an embodiment of the container 10 is manufactured in accordance with the method described below and illustrated in FIGS. 11 to 15. In this respect, the space between the liner 22 and the inner surface 16 may not necessarily consist entirely of the void space 202. Also, it is understood that the fraction of the space between the liner 22 and the inner surface 16 consisting of the void space 202 may become smaller in volume during use of the container 10, due to periodic ingress of the metallic particles 12. In this respect, engagement or abutment of the liner 22 with the inner surface 16 is said to substantially prevent or limit ingress of the metallic particles 12 from the storage space 201 and into the void space 202.
Because the void space 202 does not contain any metallic particles 12, the void space 202 offers relatively little resistance to any displacement of the liner 22 towards the inner surface 16 in response to forces being imparted by the metallic particles 12 on the liner 22. In this respect, the void space 202 facilitates such displacement of the liner 22 so as to, at least in part, insulate the container 10 from such forces and the mechanical stresses the container 10 would otherwise experience. Such forces can arise by virtue of expansion of the metallic particles 12 due to the charging with hydrogen. This is aggravated by a localized increase in packing density of the metallic particles 12 arising from decrepitation of the metallic particles 12 (metallic particles 12 are pulverized, resulting in size reduction of the metallic particles 12) and concentration thereof. It is further understood that, although resilient, the liner 22 must not necessarily return to its exact original condition once the metallic particles contract upon the discharging of the hydrogen.
While the metallic particles 12 are being charged (i.e. during absorption of hydrogen), the space 202 contracts in response to forces imparted by the metallic particles 12 on the liner 22. This is because the metallic particles 12 expand upon absorption of hydrogen, causing the liner 22 to deform and become displaced in closer proximity to the inner surface 16. With an increase in packing density, the available space between the metallic particles 12, for accommodating the expansion of the metallic particles 12, decreases, resulting in stress being applied to the liner 22. Such stress is at least partially relieved by (i) elastic deformation of the liner 22, and (ii) distribution of stress by the liner 22. While the metallic particles 12 are being discharged (i.e. during desorption of hydrogen), the metallic particles 12 contract in volume, thereby relieving at least some of the forces that would have been previously being imparted by the metallic particles 12 while the metallic particles 12 were in a charged state. As a result, and owing to its resiliency, the liner 22 reverses at least a portion of its deformation (that is, deformation resulting from the previous charging of the metallic particles 12) during discharging.
The liner 22 is disposed in the interior space 20 such that at least a portion of the void space 202 is disposed between the sidewall 163 and at least a portion of the liner 22. In the embodiment illustrated, the liner 22 has a substantially tubular form. In this respect, the liner 22 is disposed between the sidewall 163 and the axis 11 of the container 10 and extends 360° about the axis 11. At least a portion of the liner 22 opposes a sidewall 163. In this respect, the sidewall 163 extends 360° about the axis 11 in a plane 13 perpendicular to the axis 11, and at least a portion of the liner 22 is disposed between the sidewall 163 and the axis 11 and extends 360° about the axis 11 in the plane 13.
Referring to
Referring to
The liner 22 is constructed of spring steel (low carbon steel) SAE 1010 (having a tensile strength of 50-60 ksi, a yield strength of 30-40 ksi, a modulus of elasticity of about 29,000,000 psi, and a modulus of rigidity of about 11,000,000 psi). Owing to a combination of these features, including the corrugations 202, and geometry, the liner 22 is configured to facilitate stress distribution within the container 10 (relative to the case where there is no liner 22).
The nozzle 24 is configured for fluid coupling to a conduit for effecting delivery of hydrogen being discharged from the metallic particles 12 from within the container space 20 to a downstream operation, such as a fuel cell or an internal combustion engine. The conduit also facilitates supply of hydrogen to the container 10 to effect charging of the metallic particles 12.
Heat is imparted to and dissipated from the container 10 by contacting the container 10 with a fluid (liquid or gas, such as water or ambient air) which acts as a heat sink or heat source as required. The container 10 must be cooled to effect charging, and must be heated to effect discharging.
Referring to
The tubes 30 play a role in containing a portion of the expansion forces of the expanding metallic particles 12, thereby reducing stresses on the liner 22 and, thus, the container 10. In this respect, the tubes reduce the influence of the expanding metallic particles 12 on the container 10.
The tubes 30 also play a role in limiting the creation of differences in localized packing density of the metallic particles 12 within the storage space 201. This is because the tubes 30 function as physical barriers, limiting migration of the metallic particles.
To facilitate migration of hydrogen gas during charging and discharging, each of the tubes 30 can include a plurality of very small apertures or perforations 301. Preferably, these apertures or perforations have a maximum diameter of {fraction (1/32)}″ or smaller. Such apertures are small enough to allow the migration of the hydrogen gas, but prevent the metallic particles 12 within the tubes 30 from migrating outside of the tubes 30 and thereby exerting additional forces on adjacent materials or surfaces during expansion.
At least one of the plurality of tubes 30 can be in the form of a solid sintered filter cylinder that would provide a permeable solid to assist in the absorption and desorption of hydrogen gas while not allowing the migration of metallic particles 12. In one embodiment, the solid sintered filter cylinder comprises 316 L stainless steel.
Referring to
A method of assembling an embodiment of the container 10 will now be described. A container 10 is provided, having a length of 355 mm defined by the distance between its terminal ends identified by reference numerals 101, 102 in
Referring to
Referring to
Referring to
With the liner 22 disposed in the container space 20, magnetic forces are applied to the container 10 to effect positioning of the liner against the inner wall 16 of the container 10. In this respect, the magnetic forces attract the liner 22 towards the inner wall 16 (see
An apparatus 600 for applying the above-described magnetic forces is illustrated in
While the magnetic forces are continuing to be applied to the liner 22, the tubes 30 are inserted into the container space 20 through the nozzle 24. With the container 10 having the dimensions specified above, twenty-eight tubes 30, each having an outside diameter of 12.7 mm, a wall thickness of 0.8 mm, and a length of 263 mm, are inserted into the container space 20. Once all of the thirty-one tubes 30 are disposed in the container space 20, tubes 30 are disposed in a tightly packed configuration and are pressing liner 22 against the inner surface 16 of the container 10. As a result, the magnetic force being applied by the magnetic material 608 is no longer required to urge the liner 22 against the inner surface 16 and thereby effect its disposition against the inner wall 16 (i.e., bearing of the lips 224a, 224b against the inner wall 16). The container 10 can now be removed from within the passage 604 of the plastic tube 302.
In this condition, the lips 224a, 224b of the liner 22 engage the inner surface 16 for (i) defining a storage space 201 configured to contain the metallic particles 12 and also (ii) for defining a void space 202 configured to contract as the metallic particles 12 expand upon absorption of hydrogen, such that the engagement of the liner 22 to the inner surface 16 substantially prevents or limits ingress of the metallic particles 12 into the void space 202 from the storage space 201. At this point, an embodiment of the container 10 assembled in accordance with the just described method substantially assumes the condition illustrated in
It is understood that, by virtue of the assembly of an embodiment of the container 10 by the method above-described, the engagement of the liner 22 to the inner surface 16 substantially prevents ingress of the metallic particles into the void space 202 and does not completely prevent ingress into the void space 202. This is because, even after the tubes 30 are inserted into the container space 20 and thereby press against the liner 22, and particularly press the first and second ends 221, 222 against the inner surface 16 while simultaneously pressing portions of the liner 22 at opposite edges 225, 226 against each other to effect overlap of edges 225, 226, a very small space or spaces between the liner 22 and the inner surface 16 continue to exist and define a potential passage or passages for ingress of metallic particles 12 into the void space 202 from the storage space 201. However, where the metallic particles 12 are sufficiently large (e.g. where 77% of the metallic particles 12 have a particle size greater than 150 microns, and more particularly where 20% are within the range of 1000 to 2800 microns, 23% are within the range of 500 to 1000 microns, 34% are within the range of 150 microns, and the remainder under 150 microns), such space or spaces, defined in an embodiment of the container 10 created by the method described above, are sufficiently small so that any periodic ingress is relatively insignificant. In this respect, such ingress can also be characterized as being substantially prevented or limited.
Although the disclosure describes and illustrates preferred embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications may occur to those skilled in the art within the scope of the invention. For definition of the invention, reference is to be made to the appended claims.
Number | Date | Country | Kind |
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2,427,725 | May 2003 | CA | national |
Number | Date | Country | |
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60509256 | Oct 2003 | US | |
60501017 | Sep 2003 | US |