RELATED APPLICATIONS
This application claims priority to Taiwan Application Serial Number 99140823, filed Nov. 25, 2010, which is herein incorporated by reference.
BACKGROUND
1. Field of Invention
The present invention relates to a solid-state hydrogen storage device.
2. Description of Related Art
Owing to the rapid consumption of traditional energies, the higher oil price, and the arise of environmental consciousness, the new energy sources are desired to be explored all over the world, and the hydrogen energy, deemed a pure energy, is paid more and more attention. The requirements of hydrogen storage system in the hydrogen energy industry are safety, larger volume, and convenience. Although the hydrogen energy has an expectable potential value, but a major drawback of using hydrogen is that there is no satisfying hydrogen storage approach. The hydrogen, like natural gases, can be stored in a large water-sealing tank under a lower pressure. The approach is adapted for large scaled gas storage, but it is rarely applied to hydrogen because the density of the hydrogen is too small. The commonest and the most direct approach to store hydrogen is high-pressure gaseous-compressed hydrogen storage, which is capable of liberating the hydrogen by adjusting the reducing valve. But, the drawback of high-pressure gaseous-compressed hydrogen storage is requiring other kinds of energy to compress gas, which is high-energy consumption. Liquid hydrogen can be a form of storing hydrogen, which can be produced by adiabatic expanding under a high pressure. The boiling point of liquid hydrogen is only 20.38 K, and the latent heat of liquid hydrogen is only 0.91 kJ/mol. Therefore, there exists a larger temperature difference between the liquid hydrogen and the environment, so that the liquid hydrogen will evaporate rapidly whenever there is a little heat permeated into the storage container of the liquid hydrogen. The biggest problem of storing liquid hydrogen is that the liquid hydrogen is hard to be preserved for a long time. Because the heat cannot be isolated perfectly, there is always a little liquid hydrogen evaporates, so as to increase the pressure in the storage container and thus loss hydrogen. There is a technology of storing and fixing hydrogen in a metal hydride, which can be formed by combining hydrogen with many kinds of metal or alloy under certain temperatures and certain pressures. The reaction has a nice performance of reversibility, and properly increasing the temperature or decreasing the pressure can cause an adverse reaction to liberate hydrogen. Some metals or alloys can be deemed excellent hydrogen storage materials because of the high performance of storing hydrogen. Although being convenient and safety, the performance of storing hydrogen of the solid-state hydrogen storage technology still has a lot to be improved.
A hydrogen storage alloy will generate heat during hydrogen absorption. The heat must be removed properly, or the speed of hydrogenation will slow down. In a worse situation, the hydrogen storage alloy may stop liberating hydrogen, and it is a serious problem to a hydrogen storage system needed to constantly provide hydrogen. Moreover, the powder of the hydrogen storage alloy will be micronized after several cycles of hydrogen absorption and desorption. The phenomenon will cause the powder of the hydrogen storage alloy to deposit at the bottom of the hydrogen storage can, and the coefficient of volume expansion of the hydrogen storage alloy is about 25% that may cause the deformation of the hydrogen storage can.
SUMMARY
In order to solve the problems of prior arts, a hydrogen storage device according to an embodiment of the invention is provided not only to adequately improve the heat conducting efficiency during hydrogen absorption/desorption of the hydrogen storage alloy, but also to divide the hydrogen storage alloy into a plurality parts so as to prevent the hydrogen storage can from being damaged by the stress concentration caused by the micronization of the hydrogen storage alloy after several cycles of hydrogen absorption/desorption. Besides, there are additionally designed hydrogen through-holes formed on the hydrogen storage can, so the reaction of hydrogen absorption/desorption can be more smooth and thus the efficiency of hydrogen absorption/desorption of the hydrogen storage can is able to be improved.
According to an embodiment of the invention, the hydrogen storage device is mainly used to store a hydrogen storage alloy. The hydrogen storage alloy of the embodiment includes a hydrogen storage can, at least one first partition, and at least one second partition. A main axis is defined on the hydrogen storage can. The first partition is installed in the hydrogen storage can and is capable of dividing the space in the hydrogen storage can into at least one compartment. The second partition is installed in the compartment and includes a plurality of sub-compartments for accommodating the hydrogen storage alloy. Wherein, the compartment is arranged along the major axis, and the sub-compartments are linearly arranged in at least one row perpendicular to the major axis.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:
FIG. 1 is an exploded view showing a hydrogen storage device according to one embodiment of the invention;
FIG. 2A is a stereoscopic view showing the lower cover and the heat-conducting bars in FIG. 1;
FIG. 2B is a top view showing the lower cover and the heat-conducting bars in FIG. 2A;
FIG. 3 is a top view showing the second partition in FIG. 1;
FIG. 4A is a stereoscopic view showing the clamp ring in FIG. 1;
FIG. 4B is a side view showing the clamp ring in FIG. 4A;
FIG. 5 is an exploded view showing a hydrogen storage device according to another embodiment of the invention; and
FIG. 6 is an exploded view showing another embodiment of the hydrogen storage device in FIG. 5.
DETAILED DESCRIPTION
Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
A hydrogen storage device according to an embodiment of the invention is provided. The embodiment of the invention is performed to divide the hydrogen storage alloy into a plurality parts so as to prevent the hydrogen storage can from being damaged by the stress concentration caused by the micronization of the hydrogen storage alloy after several cycles of hydrogen absorption/desorption. Besides, there are additionally designed hydrogen through-holes formed on the hydrogen storage can, so the reaction of hydrogen absorption/desorption can be more smooth and thus the efficiency of hydrogen absorption/desorption of the hydrogen storage can is able to be improved. The advantage and spirit of the electrical connector of the invention may be understood by the following recitations together with the appended drawings.
Please refer to FIG. 1. FIG. 1 is an exploded view showing a hydrogen storage device 1 according to one embodiment of the invention.
As shown in FIG. 1, the hydrogen storage device 1 of the embodiment includes a hydrogen storage can 10, an upper cover 12, a lower cover 14, heat-conducting bars 16, first partitions 18, second partitions 20, and first filters 22. The upper cover 12 can be detachably installed at the top of the hydrogen storage can 10, the lower cover 14 can also be detachably installed at the bottom of the hydrogen storage can 10, and the heat-conducting bars 16 can be secured to the lower cover 14.
As shown in FIG. 1, a main axis L is defined on the hydrogen storage can 10 of the embodiment. The first partitions 18 are installed in the hydrogen storage can 10. The first partitions 18 can be used to divide the space in the hydrogen storage can into a plurality of compartments. The second partitions 20 are installed in the compartments divided by the first partitions 18. The second partitions 20 can include a plurality of sub-compartments for accommodating the hydrogen storage alloy. On a practical operation, the hydrogen storage alloy will be uniformly divided into a plurality of stacks of powder and be respectively stored in the sub-compartments. Therefore, the stress concentration caused by the expansion of the powder of the hydrogen storage alloy can be reduced. Generally speaking, the inner wall of each sub-compartment 200 of the second partitions 20 is parallel to the main axis L, and each sub-compartment 200 is adjacent to at least two other sub-compartments 200. Moreover, the compartments, divided by the first partitions 18, in the hydrogen storage can 10 are arranged along the main axis L.
As shown in FIG. 1, in the hydrogen storage device 1 of the embodiment, the first filters 22, installed on the second partitions 20, are impermeable to the hydrogen storage alloy but permeable to hydrogen, so as to prevent the powder of the hydrogen storage alloy from leaving the sub-compartments 200 and allow the hydrogen liberated from the hydrogen storage alloy to pass through. FIG. 1 does not limit the quantities of the first partitions 18, the second partitions 20, and the first filters 22.
In an embodiment, the pore size of the first filters 22 can, but not limited to, be smaller than 0.02 micrometer. The pore sizes that can prevents the powder of the hydrogen storage alloy from leaking out of the sub-compartments 200 all can be applied to the first filters 22.
In an embodiment, the first partitions 18 can be second filters for fixing the first filters 22, so as to prevent the powder of the hydrogen storage alloy from leaking out of the sub-compartments 200.
Also shown in FIG. 1, each second partition 20 has a peripheral wall 200a around the sub-compartments, and the external diameter of the peripheral wall 200a is equal to the internal diameter of the hydrogen storage can 10. Therefore, the second partitions 20 can smoothly slide, rather than shake or collide, in the hydrogen storage can 10 along the main axis L, so as to prevent the wear among components that causes the basic and important function of storing hydrogen to break down.
Please refer to FIG. 2A and FIG. 2B with FIG. 1. FIG. 2A is a stereoscopic view showing the lower cover 14 and the heat-conducting bars 16 in FIG. 1. FIG. 2B is a top view showing the lower cover 14 and the heat-conducting bars 16 in FIG. 2A.
As shown in FIG. 2A and FIG. 2B, there are four heat-conducting bars 16 secured to the lower cover 14 in the hydrogen storage device 1 of the embodiment. But, the quantity of the heat-conducting bars 16 is not limited to four, and the quantity can be modified according to the limitations during designing or actual applications. The heat-conducting bars 16 can be produced by heat-conducting metals, so as to rapidly absorb heat and guide the heat away from the lower cover 14. Each of the heat-conducting bars 16 can include a substance having high heat capacity filled inside, so as to temporarily store the heat. The design can increase the efficiency of removing or absorbing heat of the hydrogen storage alloy, so as to improve the efficiency of is hydrogen absorption/desorption of the hydrogen storage alloy.
Please refer to FIG. 3 with FIG. 2A and FIG. 2B. FIG. 3 is a top view showing the second partition 20 in FIG. 1.
As shown in FIG. 3, the sub-compartments 200 of the second partitions 20 are linearly arranged in at least one row perpendicular to the major axis L. The arrangement pattern of the sub-compartments 200 can be, but not limited to, honeycomb shaped. For example, the arrangement pattern of the sub-compartments 200 can also be radial or any kind of polygon-shaped. As shown in FIG. 3, the contour of each sub-compartment 200 is hexagon-shaped, but the contour can also be triangle or quadrilateral. By means of designing the contour of each sub-compartment 200 to be polygon-shaped, the contact area between the powder of hydrogen storage alloy and the heat-dissipating material can be greatly increased, so as to improve the ability of heat absorption/removal of the hydrogen storage device 1.
As shown in FIG. 3, positioning holes 202, corresponding (not only the quantity but also the positions) to the heat-conducting bars 16 on the lower cover 14, are formed in the second partition 20. The positioning holes 202 of the second partition 20 are mainly for the heat-conducting bars 16 to pass through. The inner walls of the positioning holes 202 are parallel to the major axis, so that the heat-conducting bars 16 on the lower cover 14 are capable of inserting into the positioning holes 202 of the second partition 20 along the main axis L. Thus, the heat-conducting bars 16 can be used for conducting away the heat generated by the hydrogen storage alloy in the sub-compartments 200 around the positioning holes 202. In an embodiment, the heat-conducting bars 16 and the positioning holes 202 can be tight fit, so as to prevent the second partition 20 from moving relative to the heat-conducting bars 16.
Furthermore, as shown in FIG. 3, a first hydrogen through-hole 204 can be formed in the second partition 20 for the hydrogen liberated from the hydrogen storage alloy to pass through, so that the speed and the uniformity of hydrogen circulating from the upper part to the lower part of the hydrogen storage can 10 can be increased. FIG. 3 does not limit the quantity of the first hydrogen through-hole 204. Similarly, the inner wall of the first hydrogen through-hole 204 can be parallel to the main axis L.
In an embodiment, in order to form the positioning holes 202 and the first hydrogen through-hole 204 in the second partition 20 conveniently, a practicable approach is taking certain sub-compartments 200 as the positioning holes 202 and the first hydrogen through-hole 204.
Please refer to FIG. 4A and FIG. 4B with FIG. 1. FIG. 4A is a stereoscopic view showing the clamp ring 24 in FIG. 1. FIG. 4B is a side view showing the clamp ring 24 in FIG. 4A.
As shown in FIG. 4A and FIG. 4B, the clamp ring 24 can be used to fix the positions of the first partitions 18 and the first filters 22 in the hydrogen storage can 10 and is capable of being detachably connected to two second partitions 20. In an embodiment, the upper rim and the lower rim of the clamp ring 24 can respectively include pinholes 240 for being inserted by pins (not shown), so as to fix the first partitions 18 and the first filters 22. Moreover, the clamp ring 24 can include second hydrogen through-holes for the hydrogen liberated from the hydrogen storage alloy in the sub-compartments 200 to pass through, so that the speed and the uniformity of hydrogen circulating in the hydrogen storage can 10 can be increased. FIG. 4A and FIG. 4B do not limit the quantity of the second hydrogen through-holes 242.
Please refer to FIG. 5 with FIG. 3. FIG. 5 is an exploded view showing a hydrogen storage device 1 according to another embodiment of the invention.
As shown in FIG. 5, one difference between the hydrogen storage device 3 of the embodiment and the hydrogen storage device 1 of the foregoing embodiment is that the lower cover 14 of the hydrogen storage device 1 of the foregoing embodiment is replaced to the lower cover 34 (with no heat-conducting bar 16) of the hydrogen storage device 3 of the embodiment, and another difference between the hydrogen storage device 3 of the embodiment and the hydrogen storage device 1 of the foregoing embodiment is that the heat-conducting bars 16 of the hydrogen storage device 1 of the foregoing embodiment is replaced to the heat-conducting bars 36, of which the length is equal to that of the second partitions, of the hydrogen storage device 3 of the embodiment. Practically, the length of the heat-conducting bars 36 is equal to that of the second partition 20 in the direction of the major axis L. The design provides a larger elasticity to the hydrogen storage can 10. While different kinds of hydrogen storage alloy being packed in the hydrogen storage can 10, the requirements of heat absorption/dissipation are different. At this time, in order to achieve better effect of heat transferring, the positions of the heat-conducting bars 36 can be rearranged without redesigning the lower cover 34.
The structures and functions of other components in FIG. 5 are similar to that in FIG. 1, so they will not be explained redundantly here.
Please refer to FIG. 6. FIG. 6 is an exploded view showing another embodiment of the hydrogen storage device 3 in FIG. 5.
As shown in FIG. 6, the difference between the hydrogen storage device 5 of the embodiment and the hydrogen storage device 3 of the foregoing embodiment is that the first partitions 18 and the heat-conducting bars 36 of the foregoing embodiment are integrated in the embodiment. In other words, the first partitions 58 in the hydrogen storage device 5 of the embodiment can include a plurality of slender heat-conducting bars 580. The first partitions 58 can be installed at the inner side of the peripheral wall 200a of the second partition 20, so that the heat-conducting bars 580 of the first partitions 58 can fix the first filters 22 between the first partitions 58 and the second partition 20 respectively and conduct away the heat generated by the hydrogen storage alloy in the sub-compartments 22. The foregoing design not only makes the first filters 22 be fixed between the first partitions 58 and the second partition 20 respectively, but also improves the effect of heat transferring because that the contact area between the slender heat-conducting bars 580 and the second partition 20 increases and the distributed density of the heat-conducting bars 580 is more uniform, so as to increase the effect of hydrogen absorption/desorption of the hydrogen storage can 10.
The structures and functions of other components in FIG. 6 are similar to that in FIG. 5, so they will not be explained redundantly here.
In an embodiment, if about 25% volume expansion of the hydrogen storage alloy during hydrogen absorption is taken into account, the volume of each sub-compartment 200 ranges about 0.5 cm3 to about 5 cm3 by calculating 70% filling capacity, and each sub-compartment 200 can store about 10 g to about 20 g powder of the hydrogen storage alloy.
According to the foregoing recitations of the embodiments of the invention, it is obvious that the hydrogen storage device of the invention mainly includes following advantages.
(1) The effects of heat transferring of different kinds of hydrogen storage alloys can be effectively improved by the application and the rearrangement of position of the heat-conducting bar, so as to improve the effect of hydrogen absorption/desorption of the hydrogen storage device.
(2) The design of the second partition in polygon-shaped can prevent the hydrogen storage alloy from depositing at the bottom of the hydrogen storage can after several cycles of hydrogen absorption and desorption, so as to prevent the hydrogen storage can from being damaged by the non-uniform stress caused by the deposit phenomenon.
(3) The hydrogen storage device of the invention includes predetermined pathways for hydrogen, so it is much easier for the hydrogen storage alloy to absorb or liberate hydrogen, and the efficiency of hydrogen absorption/desorption of the hydrogen storage device can be improved.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.
Patent Application
20120132545
