JPS6376997A - Container for hydrogen occlusion alloy - Google Patents

Abstract

PURPOSE:To obtain improved heat exchange effectiveness and a compact construction by providing a heat exchanging member of an integral combination of a plurality of metal plates and metal corrugated sheets laminated and adhered alternately with one another including two systems of communicating portions, the heat exchanging member being filled with hydrogen occlusion alloy and having hydrogen gas inlet/outlet pipes. CONSTITUTION:Impure gas in hydrogen gas is exhausted from an A system to the outside through a hydrogen inlet/outlet pipe 7, and a communicating portion of the A system is closed at the atmospheric or a pressure slightly lower than the pressure during occlusion. Then, mixed gas containing hydrogen gas is supplied under pressure through a hydrogen inlet/outlet pipe 8 in a B system into a container body 2. The hydrogen gas in the mixed gas is selectively occluded in an alloy 4 in the B system, and heat caused by the occlusion is transmitted through metal plates 9... and metal fins 10... to the alloy 4 in the A system. In the communicating portion of the A system, the hydrogen gas occluded and stored in the alloy is ejected therefrom by the heat, resulting in provision of high purity hydrogen gas.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a hydrogen storage alloy container for refining or storing hydrogen using a hydrogen storage alloy.

"Prior art" L aN i6, T 1Nin+, s, FeT i
? , Which hydrogen storage alloy (hereinafter simply referred to as alloy)
utilizes its hydrogen storage and release properties to store and release hydrogen.
It is being used for applications such as transportation and hydrogen purification.

When an alloy is used for such purposes, it is housed in a container that is resistant to heat and has a heat exchange function.

Conventionally, in this type of container, for example, hydrogen gas was introduced,
It is known that the alloy is filled in a bottomed cylindrical metal container body that is equipped with an inlet and outlet pipe for deriving hydrogen, and a filter is installed near the inlet and outlet pipe to prevent the alloy from moving into the inlet and outlet pipe. It is being In this container, by flowing a heat medium into the jacket provided on the outside of the container body, the alloy can be cooled or heated in response to the heat generated by hydrogen absorption in the alloy or the heat absorbed by hydrogen release. It has become.

By the way, alloys generally absorb and release hydrogen several times.

It is known that if the extraction is repeated, it will turn into powder and become a fine powder with a diameter of several microns.

``Problems to be solved by the invention'' However, such containers had the following problems.

[1] Since the alloy is movably filled in the container,
When the alloy is repeatedly stored and released in a powdered state, hydrogen storage is usually performed under a pressure of 5 to 97 cm, and release is performed under normal pressure or a pressure slightly lower than the pressure at the time of storage. Therefore, when switching from release to occlusion, the powdered alloy is moved within the container body due to this pressure difference, and each time occlusion and release are repeated, the alloy powder is unevenly distributed in one location within the container body. During hydrogen storage, the volume of the alloy increases by 15 to 20% and expands, so stress is concentrated in a part of the container due to the unevenly distributed alloy, which may lead to deformation or destruction of the container.
When the alloy is unevenly distributed within the container body, the alloy becomes agglomerated, its surface area decreases, and there is also the disadvantage that the amount of hydrogen storage and the storage rate decrease.

For this reason, various measures have been taken in the past, such as inserting cushioning material into the container to prevent uneven distribution of the alloy, and making the walls of the container thicker to prevent destruction due to internal pressure. However, it was not a fundamental solution.

[2] Heat is exchanged between the alloy and the heat medium through the wall of the container body, but because the surface area of the wall of the container body involved in heat exchange is small, the heat exchange efficiency is low, and hydrogen by the alloy is A large amount of time and energy were required for storage and release.

[3] It is divided into a container body filled with alloy and a jacket through which the heat medium flows, and the heat transfer area is small.
If you try to increase the amount of alloy filled with the purpose of improving hydrogen absorption and release capacity, you will need to increase the overall volume and weight, which will also increase the volume and weight of the container per unit weight of the alloy, making it difficult to make it more compact. There were also problems such as difficulty in reducing the weight.

"Means for Solving the Problems" Therefore, in the first aspect of the present invention, the container for a hydrogen storage alloy has a heat exchanger formed of a plurality of metal plates and a plurality of corrugated metal plates in which small holes are formed. are alternately stacked and joined together to form a multi-stage structure, and the even-numbered stages and odd-numbered stages are each grouped together to form a two-system distribution section.
Are the heat exchange parts that form these circulation parts filled with hydrogen storage alloy and the heat exchange parts? -Father? By doing so, the above problem was solved.

Further, the container for hydrogen storage alloy according to the second invention of the present invention is
The heat exchange part is made into a multi-stage structure by alternately stacking a plurality of metal plates and a plurality of corrugated metal plates in which small holes are formed and joining them together, and the even-numbered and odd-numbered stages are Together, they constitute two systems of circulation sections, and one of the heat exchange sections forming these circulation sections is filled with a hydrogen storage alloy and provided with a porous hydrogen gas inlet/output pipe, and the other heat exchange section is heated. By using it for media, the above problems were solved.

"Example" Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 6 show an example of a container for a hydrogen storage alloy according to the present invention, and reference numeral 1 in the figures indicates the container for a hydrogen storage alloy. This hydrogen storage alloy container 1 is a metal pressure-resistant container, and includes a container body 2, a heat exchange part 3, and an alloy 4.
As shown in FIGS. 1 and 2, the container main body 2, which is roughly constructed from the following, is a rectangular cylindrical pressure-resistant container. Flanges 5.6 that close the respective open ends are joined to both open ends of this container body 2, and flanges 5.6 are provided at the center of each of these flanges 5.6 for introducing hydrogen into the container body Z or A hydrogen intake/exhaust pipe 7.8 for deriving hydrogen from 2 is connected.

Inside the container body 2, as shown in FIGS. 2 to 4, a multi-stage heat exchange section 3 is provided. This heat exchange section 3 has metal fins (
It is formed by stacking units in which corrugated metal plates (10) are sandwiched in multiple stages.

The metal plate 9 is a rectangular thin plate, and the thickness of the metal plate 9 is determined depending on the type of metal forming the metal plate 9, but in the case of aluminum, it is approximately 1 to 5 mm thick.
It is said to be in the range of JIM.

As shown in FIG.
. . , a hydrogen inlet/outlet pipe 12 . . . , a partition plate 13 , and a closing plate 14 .

The corrugated plate 11 is formed by forming a plurality of mutually parallel corrugations 11 on a rectangular thin plate, and the height and pitch of the corrugations are preferably in the range of about 5 to 20+ nm, respectively. A plurality of small holes 15 are formed in this corrugated plate 11, and the inside diameter of the small holes 15 is in the range of about 0°5 to 3°. The density is approximately 1 piece per 1 to 5 CI'' of the corrugated sheet 11.

A plurality of corrugated plates 11 are arranged at predetermined intervals in a direction perpendicular to the wave direction, and the gaps between these corrugated plates 11 and the metal plate 9 are filled with corrugations as shown in FIG. Hydrogen inlet and outlet pipes 12 are arranged along the direction. As shown in FIG. 6, this hydrogen inlet/outlet pipe 12 is a porous pipe in which fine pores of several micrometers are formed in its peripheral wall to allow hydrogen gas to pass through uniformly but not to allow alloy to pass through.
A disc-shaped porous filter 16 in which micropores of several μm are formed is joined to both end surfaces of this filter by welding or the like. Further, as a material for forming the hydrogen inlet/outlet pipe 12, sintered metal, ceramic, synthetic resin, etc. are preferably used in consideration of workability, heat resistance, pressure resistance, etc.

On both sides of the corrugated plates 11 and the hydrogen inlet and outlet pipes 12 that are arranged alternately, there are rectangular partition plates 13 and blocking plates 14, respectively, in a direction perpendicular to the longitudinal direction of the hydrogen inlet and outlet pipes 12. is fixed. These partition plates 13 and occlusion plates 1
4 are metal plates 9 that sandwich metal fins 10, respectively.
．． The partition plate 13 has a circular through hole 17 into which the end of the hydrogen inlet/output pipe 12 on the side to which the porous filter 16 is joined is fitted. is formed.

The metal plate 9 and the metal fin 1O having such a configuration form a unit by sandwiching the metal fin 10 between the two metal plates 9.9. and,
This unit is stacked in multiple stages so that the closing plates 14 are sequentially and alternately arranged on the flange 5 side and the flange 6 side of the container body 2 shown in Fig. 1, and are joined together by brazing welding etc. at the points where they contact each other. has been done.

The knit constitutes a so-called plate-fin type heat exchange section 3. The material for forming the heat exchange section 3 is selected from materials that have a large heat transfer coefficient in consideration of heat exchange performance and high mechanical strength in consideration of the multi-stage structure. Specifically, materials such as aluminum and stainless steel are selected. etc. are preferably used. In this example, adjacent units share the metal plate 9.

In such a heat exchange section 3, alloy 4 is filled between the metal plates 9 and the metal fins 10 of each unit. When cooled or pressurized, this alloy 4 has the following properties:
It absorbs hydrogen and becomes a metal hydride through an exothermic reaction.
On the other hand, when this metal hydride is heated or placed under reduced pressure, it releases hydrogen through an endothermic reaction, and those with particular consideration to hydrogen storage capacity and economic efficiency are selected. , L aN is , T iM n
+, a, FeTi, etc. are used. Further, the filling amount of the alloy 4 is determined as appropriate depending on the distance between the metal plate 9 and the metal fin IO and the sizes of the metal plate 9 and the metal fin 10.

As shown in FIGS. 1 to 4, in such a heat exchange section 3, partition plates [3...] of odd-numbered units are arranged on the flange 5 side of the container body 2. A flow section is formed that consists of two systems: a system and a B system in which partitions [13...] of even-numbered units are arranged on the flange 6 side.

The end of this heat exchanger 3 on the A system side and the flange 5
As shown in FIG. 4, a gap is formed between the flange 6 and the end of the heat exchange section 3 on the B system side (not shown), and a gap similar to the above is formed between the flange 6 and the end of the heat exchange section 3 on the side of the B system (not shown). A void is formed.

Next, an example of a method for purifying hydrogen gas using the hydrogen storage alloy container I having the above structure will be described.

First, in FIG. 1, a mixed gas containing hydrogen gas is supplied under pressure into the container body 2 from the hydrogen intake/discharge pipe 7 of the A system among the two flow sections. This mixed gas passes through the hydrogen inlet/output pipe 12 and the porous filter 16 on the flange 5 side.
..., introduced into the gap between the metal plates 9.9 of each unit through the fine holes in the peripheral wall of the hydrogen inlet/output pipe 12..., and further into the gap through the small holes 15 of the corrugated plate 11. I am completely satisfied. Here, the above-mentioned mixed gas is gently ejected outward in the radial direction of the hydrogen inlet/outlet pipes 12 from the fine holes of the hydrogen inlet/outlet pipes 12 .

Therefore, by introducing this mixed gas, the alloy 4 is not moved and the alloy 4 is not unevenly distributed.

Next, hydrogen gas in the mixed gas is selectively occluded in the alloy 4 filled between the metal plates 9... and the metal fins IO... of each unit. At this time, the temperature of the alloy 4 on the A system side rises due to the exothermic reaction accompanying hydrogen absorption, but it is left to cool down to room temperature.

Next, impure gas in the hydrogen gas is exhausted to the outside from the A system side through the hydrogen suction/exhaust pipe 7, and the flow section on the A system side is closed when the pressure is normal pressure or slightly lower than the pressure at the time of storage.

Next, a mixed gas containing hydrogen gas is supplied under pressure into the container body 2 from the hydrogen suction and exhaust pipe 8 of the B system. At this time, the hydrogen gas in the mixed gas is selectively occluded in the alloy 4 on the B system side, and the heat accompanying this occlusion is transferred to the A system side through the metal plate 9... and the metal fin lO... Heat is transferred to Alloy 4. In the flow section on the A system side, the hydrogen gas occluded and held from the alloy 4 is released by the heat described above, and highly pure hydrogen gas is obtained.

In this way, if hydrogen gas is absorbed and discharged at the same time in both the flow sections on the A system side and the 13th system side, the heat generated on the B system side, which stores hydrogen gas, can be used on the A system side. Hydrogen gas can be released on the system side, so hydrogen gas can be stored and released continuously. In addition, the hydrogen suction and exhaust pipe 7 on the A system side and the hydrogen suction and exhaust pipe 8 on the B system side are connected, and the hydrogen gas stored on the A system side is released to the B system side and stored in the alloy 4 on the B system side. By repeating this process, it is possible to gradually improve the purity of hydrogen gas.

Next, an example of a method for storing hydrogen gas using the above-mentioned hydrogen storage alloy container 1 will be explained. In this case, the container l is, for example, the wave II of the metal fin 10...c)! -',
4? -,kJ-/l-r8n'rknom1M,',h:
The heat transfer area #IZ, %h7*product is configured to be larger than the heat transfer area of the flow section on the B system side. After the container I is configured as described above, alloy 4 is filled in the flow section on the A system side, and heat medium is filled in the flow section on the B system side. Next, hydrogen gas is supplied under pressure into the flow section on the A system side to cause the alloy 4 to absorb hydrogen gas. The heat associated with the storage of hydrogen gas is cooled by the heat medium on the B system side. Next, during use, the alloy 4 on the A system side is heated by the heating medium on the B system side to release hydrogen gas from the alloy 4.

In the hydrogen storage alloy container 1 of this example, the following effects can be obtained.

[1] Since the heat exchange section 3 is configured with a porous hydrogen inlet/output pipe 12, it is possible to slowly introduce hydrogen gas into the heat exchange section 3 filled with alloy 1. . Therefore, since the hydrogen gas is introduced slowly, the alloy 4 is not moved by the hydrogen gas.
Therefore, uneven distribution of alloy 4 does not occur, and this alloy 4
This prevents container destruction due to uneven distribution of the alloy 4 and volumetric expansion of the alloy 4.

[2] Since the heat exchange section 3 has a multi-stage structure in which units consisting of metal plates 9 and metal fins 10 are stacked, a large heat transfer area for heat exchange can be obtained, and each Since heat exchange is performed in each stage, high heat exchange efficiency can be obtained. Therefore, hydrogen is absorbed and released quickly by the alloy 4.

In the above embodiment, as shown in FIG. 6, the hydrogen inlet/outlet pipes 12... were assumed to have fine holes formed in the entire peripheral wall thereof, but as shown in FIGS. As shown in the figure, a configuration may be adopted in which micropores are formed in a part of the peripheral wall. That is, the inlet/outlet pipe 18 shown in FIG. 7 has fine holes formed in three parts of the entire peripheral wall: both ends and the center part. By using this inlet/outlet pipe 18, hydrogen gas can be ejected from multiple locations simultaneously.

Further, the inlet/outlet tube 19 shown in FIG. 8 has fine holes formed in a band-shaped portion of the circumferential wall along the longitudinal direction of the tube 19. In this case, the hydrogen gas can be ejected in a specific direction along the longitudinal direction of the tube 19, and since the hydrogen gas is not directly applied to the alloy 4 in the heat exchange section 3, the movement of the alloy 4 is prevented. becomes possible.

Further, in the above embodiment, the heat exchange portions 3 are arranged parallel to each other.
Although the present invention has been described as having two distribution sections, the system and the B system, the configuration may be such that these two distribution sections are orthogonal to each other.

Hereinafter, the effects of this invention will be clarified by showing experimental examples.

(Experimental Example 1) An aluminum container (a) for a hydrogen storage alloy shown in FIGS. 1 to 6 was manufactured, and the heat exchange section in the container (a) was filled with l, aNis as an alloy. Two hydrogen inlet and outlet pipes were installed in each stage of the heat exchange section of this container (a).

Container (A) (Example); width 150 mm x height 150 m
m x depth 150 mm, pitch 8 mm, wave height 6.
Twenty stages of 5 mm metal fins were used. The alloy filling amount is
It was 7 to 9.

The hydrogen inlet/outlet tube was a sintered metal pipe with an inner diameter of 3 mm, and a large number of micropores of approximately 2 μπ in diameter were formed in its peripheral wall.

A conventional multi-tubular hydrogen storage alloy container (b) was manufactured and similarly filled with LaN is as an alloy.

Container (b) (comparative example); Thick metal pipe (
Inside this metal pipe, 20 thin metal pipes (inner diameter 20 mm x total length 1500 mm) were installed as thin heat medium flow tubes.

The alloy filling amount was 500 kg.

For these hydrogen storage alloy containers, the heat transfer area, container weight per unit weight of alloy, and container volume per unit weight of alloy were measured. The measurement results are shown in Table 1.

As is clear from Table 1, the container (a) has a larger heat transfer area than the conventional container (b), and can be made lighter and more compact.

(Experiment Example 2) Using the container (a) manufactured in Experiment Example 1 and the container (d) from which the hydrogen inlet/output tube was removed from this container (a), the following measurement items were measured, and the results were reported in the It is shown in Table 2.

<1> Time required to store hydrogen (storage time): When supplying hydrogen under pressure into the container, the hydrogen temperature was 40° C., and the hydrogen pressure was 10 kg/cm'.

(2) Time required to release hydrogen (release time): The temperature inside the container during hydrogen release was 60°C, and the release pressure was atmospheric pressure.

(3) Whether or not alloy nodules are generated after hydrogen absorption and release are repeated 300 times.

Table 2 As is clear from Table 2, container (a) requires less time to absorb and release hydrogen than the comparative container (d), and the alloy is less likely to move within the container. It can be seen that no baby booms occur.

"Effects of the Invention" As explained above, the hydrogen storage alloy container of the present invention has a structure in which a porous hydrogen inlet/output pipe is disposed in the heat exchange section. Hydrogen is introduced slowly, and the alloy filled in the heat exchanger is not moved due to hydrogen or the pressure difference during intake and exhaust, so the alloy is not unevenly distributed in the heat exchanger.
This prevents the container from being destroyed due to uneven distribution of the alloy and volumetric expansion when the alloy absorbs hydrogen.

Additionally, the heat exchange part of this container is a metal plate.

Since it is a multi-stage structure made by laminating metal corrugated plates alternately and joining them together, heat transfer occurs at each stage, and the heat transfer area for heat exchange is large, resulting in high heat exchange efficiency. It will be done. Therefore, heat exchange can be performed quickly with respect to the alloy filled in the heat exchange portion of this multi-stage structure, so that hydrogen gas can be stored and released quickly by this alloy.

Furthermore, since this container is a heat exchanger with two systems of circulation parts stacked alternately, if the hydrogen gas intake and exhaust timing by the alloy is performed simultaneously for each system, heat will be mutually utilized between both systems. This eliminates the need for heating and cooling the alloy, and allows continuous storage and release of hydrogen gas.

Furthermore, since the heat exchange section of this container has a multi-stage structure, the size of the heat exchange section can be reduced while maintaining high heat exchange capacity. Since the weight can be reduced,
The entire container can be made more compact and lighter.

[Brief explanation of the drawing]

1 to 6 show an example of a container for a hydrogen storage alloy according to the present invention, in which FIG. 1 is a schematic perspective view showing the structure of the entire container, and FIG. 2 shows the structure of the heat exchange section. FIG. 3 is an enlarged schematic perspective view of the main parts of the heat exchanger, FIG. 4 is an enlarged schematic sectional view of the main parts of the container, and FIG. 5 shows the structure of the corrugated metal plate. FIG. 6 is a schematic perspective view showing the structure of a hydrogen inlet/output pipe. FIGS. 7 and 8 are schematic perspective views showing other examples of hydrogen inlet and outlet pipes used in the hydrogen storage alloy container of the present invention. DESCRIPTION OF SYMBOLS 1... Container for hydrogen storage alloy, 3... Heat exchanger (heat exchange part), 4... Alloy (hydrogen storage alloy), 9... Metal plate, IO... Metal fin (metal) corrugated plate), 15
...Small hole, 12.18.19...Hydrogen inlet and outlet pipe.

Claims (2)

[Claims] (1) In a hydrogen storage alloy container in which a hydrogen storage alloy that stores and releases hydrogen gas and a heat exchange section that exchanges heat with the hydrogen storage alloy are arranged inside the pressure container,
The heat exchange section is made into a multi-stage structure by alternately stacking a plurality of metal plates and a plurality of corrugated metal plates in which small holes are formed, and then joining and integrating them. are combined to form two circulation sections, and the heat exchange sections forming these circulation sections are filled with a hydrogen storage alloy, and the heat exchange sections are provided with porous hydrogen gas inlet and outlet pipes. Container for hydrogen storage alloy. (2) A container for a hydrogen storage alloy in which a hydrogen storage alloy that stores and releases hydrogen gas and a heat exchange section that exchanges heat with the hydrogen storage alloy are disposed inside the pressure container,
The heat exchange section is made into a multi-stage structure by alternately stacking a plurality of metal plates and a plurality of corrugated metal plates in which small holes are formed, and then joining and integrating them. are combined to form two circulation sections, and one of the heat exchange sections forming these circulation sections is filled with a hydrogen storage alloy and provided with a porous hydrogen gas inlet/output pipe, and the other heat exchange section is A container for hydrogen storage alloy, characterized in that it is used as a heat medium.