JP4706384B2 - Hydrogen storage device - Google Patents

Description

  The present invention relates to a hydrogen storage device.

  In recent years, fuel cells, engines, and the like using hydrogen as fuel have been developed, and at the same time, methods and devices for storing or storing hydrogen supplied to these engines, fuel cells, etc. are being developed.

Conventional hydrogen storage methods include, for example, a method in which a pressure of about 20 MPa is applied to hydrogen to store hydrogen in a high-pressure hydrogen cylinder, and a method in which hydrogen cooled to about 20 K and liquefied is stored in a liquid hydrogen cylinder. There is. Furthermore, a hydrogen storage device including a carbon material having pores and a container containing the carbon material is known (see, for example, Patent Document 1).
JP 2001-220101 A

  In the hydrogen storage device described in Patent Document 1, for example, a stainless steel tank or cylinder is used as a container for storing hydrogen. However, in a tank made of stainless steel or the like, when storing liquid hydrogen, heat from the outside cannot be sufficiently blocked, and it may be difficult to store hydrogen for a long period of time.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a hydrogen storage device capable of storing hydrogen over a long period of time.

  To achieve the above object, the hydrogen storage device of the present invention includes a heat insulating container for storing liquid hydrogen, a hydrogen adsorbing member disposed in the heat insulating container, an inner wall of the heat insulating container, and the hydrogen adsorbing member. An introduction pipe for introducing liquid hydrogen into an enclosed space (hereinafter, this space may be referred to as “liquid hydrogen storage part”), and a discharge pipe for discharging hydrogen gas generated from the liquid hydrogen from the inside of the heat insulating container. The introduction pipe, the hydrogen adsorption member, and the discharge pipe are arranged so that the hydrogen gas passes through the hydrogen adsorption member and is discharged from the heat insulating container.

  Since the hydrogen storage device of the present invention uses a heat insulating container, heat conduction from the outside to the heat insulating container can be suppressed, and vaporization of liquid hydrogen stored in the hydrogen storage device can be suppressed.

  When liquid hydrogen is introduced into the liquid hydrogen storage part through the introduction pipe, the liquid hydrogen boils by contacting the inner wall of the heat insulating container to generate hydrogen gas. This hydrogen gas is discharged from the discharge pipe after passing through the hydrogen adsorbing member. The temperature of the hydrogen gas generated by the boiling of liquid hydrogen is substantially the same as the boiling point of liquid hydrogen (20.4 K), and when this low-temperature hydrogen gas passes through the hydrogen adsorbing member, it takes heat from the hydrogen adsorbing member. It is discharged outside the insulated container. Therefore, it becomes possible to efficiently release the heat in the heat insulating container to the outside of the container.

  In the present invention, the hydrogen adsorbing member refers to a member made of a substance capable of adsorbing and holding hydrogen molecules on its surface, which is distinguished from a hydrogen storage alloy that captures and stores atomic hydrogen. It is.

  Further, when hydrogen gas passes through the hydrogen adsorbing member, a part thereof is adsorbed and held by the hydrogen adsorbing member. Since the hydrogen held in the hydrogen adsorption member is held in the device even after all the liquid hydrogen stored in the hydrogen storage device has evaporated, the hydrogen storage device of the present invention can store hydrogen for a long period of time. is there.

  The hydrogen storage device of the present invention may further include a partition member that partitions the hydrogen adsorption member and the liquid hydrogen storage unit. By providing the partition member, it is possible to suppress the direct contact between the liquid hydrogen and the hydrogen adsorption member when introducing the liquid hydrogen. For this reason, bumping of liquid hydrogen can be prevented.

  In the hydrogen storage device of the present invention, the hydrogen adsorbing member and the liquid hydrogen storage unit may be disposed in the horizontal direction in the heat insulating container. In this case, the hydrogen storage device of the present invention is provided with a partition member that partitions the hydrogen adsorption member and the liquid hydrogen storage unit. By arranging the hydrogen adsorbing member and the liquid hydrogen storage portion in the horizontal direction, the degree of freedom of the layout of the hydrogen storage device can be expanded.

  In the hydrogen storage device of the present invention, a partition wall may be provided in the hydrogen adsorbing member so that hydrogen gas meanders and passes through the hydrogen adsorbing member. By causing the hydrogen gas to meander in the hydrogen adsorbing member, the contact area between the hydrogen adsorbing member and the hydrogen gas can be increased, and the hydrogen adsorption capacity can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen storage apparatus which can store hydrogen over a long period can be provided.

  The hydrogen storage device of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is provided to the member which has the same function throughout all drawings, and the description may be abbreviate | omitted.

<First embodiment>
FIG. 1 is a diagram showing a hydrogen storage device according to a first embodiment of the present invention, FIG. 1 (A) shows a perspective view of the hydrogen storage device, and FIG. 1 (B) shows A in FIG. A cross-sectional view taken along the line -A. The hydrogen storage device according to the first embodiment includes a heat insulating container 10, and an introduction pipe 20 and a discharge pipe 30 provided on the top of the heat insulating container 10.

  As shown in FIG. 1B, the heat insulating container 10 includes a tank 12 and a heat insulating material 14 that covers the outside of the tank 12.

  As the tank 12, a SUS or stainless steel tank or the like can be used, but is not limited thereto.

  Multilayer insulation (MLI) can be used as the heat insulating material 14. The MLI is configured by alternately laminating a thin-film radiation shield material having a high reflectance and a spacer material for preventing heat conduction between the shield materials. As the shield material, a single-sided or double-sided aluminum-deposited polyester film or the like is used, and as the spacer material, glass fiber cloth, paper, nylon net, or the like is used. The MLI can reduce the amount of heat entering due to radiation to 1 / (N + 1) when N shield materials are inserted.

A hydrogen adsorbing member 40 is disposed inside the heat insulating container 10. Examples of the hydrogen adsorbent constituting the hydrogen adsorbing member 40 include activated carbon, carbon nanotubes, MOF (porous metal organic structure) such as Zn ₄ O (dimethyl 1,4-benzenedicarboxylate) _{3 and the} like. These materials are used in the form of granules, pellets, or powders of these materials packed in a bag. In the present embodiment, pellet-shaped activated carbon is used.

  The introduction pipe 20 is communicated with the liquid hydrogen reservoir 50 which is a space surrounded by the inner wall of the heat insulating container 10 and the hydrogen adsorbing member 40, and liquid hydrogen is supplied into the heat insulating container 10 without directly touching the hydrogen adsorbing member 40. It can be done.

  Each of the introduction pipe 20 and the discharge pipe 30 is provided with a valve 60. The valve 60 is covered with the heat insulating material 14, and can prevent the heat | fever approach which hydrogen gas itself becomes a heat medium.

  Next, the operation of each component when liquid hydrogen is stored in the hydrogen storage device according to the first embodiment will be described.

  When liquid hydrogen is supplied to the liquid hydrogen reservoir 50 through the introduction pipe 20, depending on the temperature of the inner wall of the tank 12, a part of the liquid hydrogen is vaporized to generate hydrogen gas near the liquid hydrogen temperature. The hydrogen gas passes through the hydrogen adsorbing member 40 and is then discharged from the heat insulating container 10 through the discharge pipe 30. When passing through the hydrogen adsorbing member 40, heat exchange occurs between the hydrogen gas and the hydrogen adsorbing member 40, cooling the hydrogen adsorbing member 40 and partially adsorbing and holding the hydrogen adsorbing member 40. Since the hydrogen gas takes heat from the hydrogen adsorbing member 40 and is discharged from the heat insulating container 10, the heat insulating container 10 can be efficiently cooled. Further, heat of adsorption is generated when hydrogen gas is adsorbed to the hydrogen adsorbing member 40, but the heat of adsorption is also discharged out of the heat insulating container 10 by the hydrogen gas discharged from the heat insulating container 10.

  As the inner wall of the tank 12 is cooled, the vaporization of liquid hydrogen is stopped, and the liquid hydrogen is stored in the liquid hydrogen storage unit 50. Since the hydrogen adsorbing member 40 made of pellet-like activated carbon has gaps between the pellets, it is possible to store in the heat insulating container 10 liquid hydrogen that is equal to or larger than the volume of the liquid hydrogen storage unit 50. After sufficient hydrogen has been adsorbed on the hydrogen adsorbing member 40, even if liquid hydrogen touches the hydrogen adsorbing member 40, no heat of adsorption is generated and no liquid hydrogen bumps.

  Moreover, pressure loss can be made small by using the hydrogen adsorption member 40 comprised with the pellet-shaped activated carbon, As a result, the filling time of liquid hydrogen can be shortened.

  When liquid hydrogen is stored after the supply of liquid hydrogen is finished, liquid hydrogen may boil due to heat entering the heat insulating container 10 from the outside, and hydrogen gas near the liquid hydrogen temperature may be further generated. Also in this case, since the hydrogen gas is discharged from the heat insulating container 10 after passing through the hydrogen adsorption member 40, the heat insulating container 10 can be efficiently cooled.

  As described above, according to the hydrogen storage device of the present invention, the hydrogen gas in the vicinity of the liquid hydrogen temperature can be effectively used for cooling the inside of the heat insulating container 10, so that the storage efficiency of liquid hydrogen can be improved. At the same time, liquid hydrogen can be stored for a long time.

  Next, a modified example of the hydrogen storage device according to the first embodiment will be described. FIG. 2: represents the sectional view on the AA line of the hydrogen storage apparatus which concerns on the 1st modification of 1st embodiment. The hydrogen adsorbing member 40 according to FIG. Thereby, the rate of heat exchange between the hydrogen gas and the hydrogen adsorbing member 40 and the adsorption rate of the hydrogen gas can be increased, and the introduction rate of liquid hydrogen can be improved.

  Instead of providing the slit 42 in the hydrogen adsorbing member 40, the pellet is arranged so that the diameter of the activated carbon (pellet) constituting the hydrogen adsorbing member 40 becomes smaller as it proceeds from the liquid hydrogen reservoir 50 side to the discharge pipe 30 side. You can also. Thereby, the same effect as the case where the slit 42 is provided in the hydrogen adsorption member 40 is acquired.

  FIG. 3: represents the sectional view on the AA line of the hydrogen storage apparatus which concerns on the 2nd modification of 1st embodiment. A partition wall 44 is provided in the hydrogen adsorption member 40 so that hydrogen gas can pass through the hydrogen adsorption member 40 in a meandering manner. Thereby, the rate of heat exchange between the hydrogen gas and the hydrogen adsorbing member 40 and the adsorption rate of the hydrogen gas can be increased, and the introduction rate of liquid hydrogen can be improved.

<Second embodiment>
FIG. 4 is a view showing a hydrogen storage device according to the second embodiment of the present invention. FIG. 4 (A) is a perspective view of the hydrogen storage device, and FIG. 4 (B) is a view of FIG. 4 (A). A sectional view taken along line BB is shown. In the hydrogen storage device according to the second embodiment, the hydrogen adsorption member 40 and the liquid hydrogen reservoir 50 are arranged in the horizontal direction. The partition member 70 partitions the hydrogen adsorbing member 40 and the liquid hydrogen storage unit 50, so that liquid hydrogen and the hydrogen adsorbing member 40 can be prevented from coming into direct contact when liquid hydrogen is supplied from the introduction pipe 20. . For this reason, bumping of liquid hydrogen due to heat of adsorption can be prevented, and the introduction speed of liquid hydrogen can be improved.

  By making the hydrogen storage device of the present invention into such an embodiment, the shape of the tank 12 can be made thin. Therefore, when the hydrogen storage device is used as, for example, a fuel tank of a fuel cell vehicle, it is advantageous in mounting.

<Third embodiment>
FIG. 5 is a view showing a hydrogen storage device according to the third embodiment of the present invention, FIG. 5 (A) is a perspective view of the hydrogen storage device, and FIG. 5 (B) is a view of FIG. 5 (A). A CC line sectional view is shown. In the hydrogen storage device according to the third embodiment, the hydrogen adsorption member 40 and the liquid hydrogen storage unit 50 are arranged in the horizontal direction.

  The liquid hydrogen reservoir 50 is provided with a cylindrical liquid hydrogen receiving tray 80. The bottom of the liquid hydrogen receiving tray 80 is in contact with the tank 12. The liquid hydrogen receiving tray 80 can be formed of a SUS material or aluminum.

  The liquid hydrogen supplied through the introduction pipe 20 is first stored in the liquid hydrogen receiving tray 80. Since the liquid hydrogen receiving tray 80 has a lower heat capacity than the tank 12, it is possible to suppress bumping of liquid hydrogen. Further, since the bottom of the liquid hydrogen receiving tray 80 and the tank 12 are in contact with each other, the liquid hydrogen receiving tray 80 can promote heat transfer from the liquid hydrogen to the tank 12.

  A porous magnetic body 90 that is a para-ortho conversion catalyst is provided in the vicinity of the discharge port of the discharge pipe 30. Hydrogen includes para-hydrogen and ortho-hydrogen based on the difference in angular momentum between spins. At normal temperature, ortho hydrogen and para hydrogen are present in a ratio of 3: 1. However, at low temperatures, para hydrogen has lower energy, and therefore all exist as para hydrogen. The para-ortho conversion is an endothermic reaction.

  The hydrogen gas that passes through the hydrogen adsorbing member 40 and is released to the outside of the heat insulating container 10 through the discharge pipe 30 is parahydrogen. By arranging the para-ortho conversion catalyst in the vicinity of the discharge port of the discharge pipe 30, para-ortho conversion, which is an endothermic reaction, occurs. Thereby, the location where the para-ortho conversion catalyst is arranged in the discharge pipe 30 is cooled, and heat can be prevented from being transmitted to the tank 12 through the discharge pipe 30.

  Specific examples of the para-ortho conversion catalyst include iron oxide and the like.

  In the hydrogen storage device according to the first to third embodiments described above, there is a gap that communicates with the discharge pipe 30. This gap is provided in order to efficiently discharge the hydrogen gas. In the present invention, this gap is not necessarily provided.

  Further, hydrogen gas may be taken out from the discharge pipe 30, or when a hydrogen take-out pipe having a smaller diameter than the discharge pipe 30 is further provided to supply liquid hydrogen (when a large amount of hydrogen gas needs to be released) ) May be discharged from the discharge pipe 30, and when using hydrogen gas (when it is necessary to release a small amount of hydrogen gas), the hydrogen gas may be taken out from the hydrogen take-out pipe.

  In the present invention, the ratio of the volume occupied by the hydrogen adsorbing member 40 and the volume occupied by the liquid hydrogen storage unit 50 in the heat insulating container 10 is appropriately determined in consideration of the purpose of use of the hydrogen storage device, etc. It is not limited.

It is a figure showing the hydrogen storage apparatus which concerns on 1st embodiment of this invention, (A) represents the perspective view of a hydrogen storage apparatus, (B) represents the sectional view on the AA line. It is an AA line sectional view of a hydrogen storage device concerning the 1st modification of a first embodiment. It is an AA line sectional view of the hydrogen storage device concerning the 2nd modification of a first embodiment. It is a figure showing the hydrogen storage apparatus which concerns on 2nd embodiment of this invention, (A) represents the perspective view of a hydrogen storage apparatus, (B) represents the BB sectional drawing. It is a figure showing the hydrogen storage apparatus which concerns on 3rd embodiment of this invention, (A) represents the perspective view of a hydrogen storage apparatus, (B) represents CC sectional view taken on the line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Thermal insulation container 12 Tank 14 Thermal insulation material 20 Introducing pipe 30 Discharge pipe 40 Hydrogen adsorption member 42 Slit 44 Partition 50 Liquid hydrogen storage part 60 Valve 70 Partition member 80 Liquid hydrogen receiving tray 90 Porous magnetic body

Claims (4)

An insulated container for storing liquid hydrogen;
A hydrogen adsorbing member disposed in the heat insulating container;
An introduction pipe for introducing liquid hydrogen into a space surrounded by the inner wall of the heat insulating container and the hydrogen adsorbing member;
A discharge pipe for discharging hydrogen gas generated from the liquid hydrogen from the inside of the heat insulating container;
And a hydrogen storage device in which the introduction pipe, the hydrogen adsorption member, and the discharge pipe are arranged so that the hydrogen gas passes through the hydrogen adsorption member and is then discharged from the heat insulating container.   The hydrogen storage device according to claim 1, further comprising a partition member that partitions the hydrogen adsorption member and the space.   The hydrogen storage device according to claim 2, wherein the hydrogen adsorption member and the space are arranged in a horizontal direction in the heat insulating container.   The hydrogen storage device according to any one of claims 1 to 3, wherein a partition wall is provided in the hydrogen adsorption member so that the hydrogen gas passes through the hydrogen adsorption member in a meandering manner.

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