JP2006029396A - Hydrogen storage vessel and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen storage vessel and a hydrogen storage device having high heat conductivity and gas flowability, and having a simple structure of light weight. <P>SOLUTION: This hydrogen storage vessel comprises a honeycomb structure 2 composed of porous metal having communication holes, a hydrogen storage bodies 3 filled in cavities of the honeycomb structure 2, a storage container 4 for storing the honeycomb structure and the hydrogen storage bodies 3, and a heating part 9 for indirectly heating the hydrogen storage bodies 3 from an outer side of the storage container 4, or indirectly heating the hydrogen storage bodies 3 by heating the honeycomb structure. As the honeycomb structure 2 is composed of the porous metal, the permeability of a hydrogen gas can be improved while keeping high heat conductivity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydrogen storage container and a hydrogen storage device including a hydrogen storage body that absorbs and releases hydrogen.

2. Description of the Related Art Conventionally, hydrogen storage containers that store and release hydrogen by heating a hydrogen storage body such as a hydrogen storage alloy filled in the container from the outside of the container are known. The hydrogen storage body is a powder that can occlude or release hydrogen when activated by being heated above a certain temperature. On the other hand, a hydrogen storage tank has been proposed in which a heat medium pipe and a fin portion extending from the heat medium pipe are fitted in a container in order to improve the heat conductivity to the hydrogen storage body (for example, Patent Documents). 1). In such a storage tank, the hydrogen storage metal is stored in a space defined by the outer cylinder member, the heat medium pipe, and the fin, and the heat medium flows through the heat medium pipe inside the container, and passes through the fin from the heat medium pipe. Heat is transferred to the hydrogen storage metal.
Japanese Patent Laid-Open No. 6-281997

  However, a general hydrogen storage body is powder, and heat conductivity is poor even when heated from outside the container, and it is difficult to uniformly heat the hydrogen storage body in the container. In particular, the larger the capacity of the container, the more difficult it is to uniformly heat the hydrogen storage body.

  On the other hand, like a container exemplified in Patent Document 1, a heat medium pipe is provided inside a hydrogen storage container, a heat solvent is allowed to flow in the heat medium pipe, and the heat conduction fins connected to the heat medium pipe are provided. There is a method of spreading heat, but in this case, the structure inside the container becomes complicated. When the pipe has a spiral or complicated U-shaped tube structure, the thermal conductivity is improved, but the inside of the container becomes more complicated, and the powder of the hydrogen storage body cannot be efficiently filled. Moreover, when the heat medium pipe and the heat conducting fin connected to the heat medium pipe are provided, the weight of the entire container increases.

  In addition, in the hydrogen storage container, it is necessary to ensure gas flowability because hydrogen is stored in the hydrogen storage body and hydrogen is released from the hydrogen storage body. If provided, the gas flow is hindered.

  An object of the present invention is to provide a hydrogen storage container and a hydrogen storage device that have high thermal conductivity, good gas flow, simple structure, and light weight.

  In order to achieve the above object, a hydrogen storage container according to the present invention includes a honeycomb structure made of a porous metal having communication holes, a hydrogen storage body filled in a void of the honeycomb structure, and the honeycomb. A container containing the structure and the hydrogen storage body, and indirectly heating the hydrogen storage body from outside the container, or indirectly heating the honeycomb structure by heating the honeycomb structure And a heating unit.

  Thus, the honeycomb structure of the hydrogen storage body of the present invention is made of metal. Thereby, the thermal conductivity of the honeycomb structure can be improved, and the hydrogen storage body filled in the cells of the honeycomb structure can be heated uniformly. In addition, since the hydrogen storage body is partitioned and partitioned in a honeycomb structure, heat can easily be efficiently transmitted to the entire hydrogen storage body filled in the honeycomb cells. The metal constituting the honeycomb structure is porous having communication holes. Thereby, the air permeability of hydrogen gas can be improved while maintaining high thermal conductivity.

  Moreover, it can be set as a simple structure compared with the structure of the internal heating which passes a heat-medium pipe | tube inside a container. In addition, since the heating method is not internal heating using a heat medium pipe or the like, there is no inconvenience that the medium leaks when subjected to some impact.

  In addition, it is preferable that the hydrogen storage container further includes a covering portion having a communication hole having a diameter smaller than an average hole diameter of the honeycomb structure on a surface of the honeycomb structure. Thereby, the flowability of gas can be improved while preventing powder particles of the hydrogen storage body from entering the surface of the honeycomb structure and causing clogging.

  Moreover, it is suitable for the hydrogen storage container that the outer shape is formed in a substantially polygonal column. Thereby, a plurality of hydrogen storage containers can be arranged and used as an aggregate, and a hydrogen storage device can be produced according to the required capacity. Moreover, since the external shape is a polygonal column, it can be filled densely. In addition, the production cost can be reduced by mass production as a unit.

  Further, the hydrogen storage device of the present invention is a hydrogen storage device including a plurality of the hydrogen storage containers according to any one of the above, and a temperature control unit that uniformly controls the temperature of the heating unit of each of the hydrogen storage containers And a flow path forming part for forming a flow path for circulating hydrogen in each of the hydrogen storage containers. As a result, a plurality of hydrogen storage containers can be collectively assembled and controlled as a hydrogen storage device, and a large volume of hydrogen can be taken in and out efficiently. In addition, it is possible to manufacture an efficient hydrogen storage device at low cost compared to manufacturing a large-capacity hydrogen storage device.

  According to the hydrogen storage container of the present invention, since the honeycomb structure is made of metal, the thermal conductivity of the honeycomb structure is improved, and the hydrogen storage body filled in the cells of the honeycomb structure is heated uniformly. Can do. In addition, since the hydrogen storage body is partitioned and partitioned in a honeycomb structure, heat can easily be efficiently transmitted to the entire hydrogen storage body filled in the honeycomb cells. Further, since the metal constituting the honeycomb structure is porous having communication holes, it is possible to improve the hydrogen gas permeability while maintaining high thermal conductivity. Moreover, it can be set as a simple structure compared with the structure of the internal heating which passes a heat-medium pipe | tube inside a container. In addition, since the heating method is not internal heating using a heat medium pipe or the like, there is no inconvenience that the medium leaks when subjected to some impact.

  In addition, according to the hydrogen storage container of the present invention, gas flowability can be improved while preventing powder particles of the hydrogen storage body from entering the surface of the honeycomb structure and causing clogging. In addition, according to the hydrogen storage container of the present invention, a plurality of hydrogen storage containers can be arranged and used as an aggregate, and a hydrogen storage device can be produced according to the required capacity. Moreover, since the external shape is a polygonal column, it can be filled densely. In addition, the production cost can be reduced by mass production as a unit.

  Moreover, according to the hydrogen storage device according to the present invention, a plurality of hydrogen storage containers can be collectively assembled and controlled as a hydrogen storage device, and a large capacity of hydrogen can be taken in and out efficiently. In addition, it is possible to manufacture an efficient hydrogen storage device at low cost compared to manufacturing a large-capacity hydrogen storage device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

[Embodiment 1]
FIG. 1 is a cross-sectional view of the hydrogen storage container 1. As shown in FIG. 1, the hydrogen storage container 1 includes a honeycomb structure 2, a hydrogen storage body 3, a container 4, a gas flow port 6, a valve 7, a gas flow tube 8, a heater 9, and a heat insulating material 10. Yes. The hydrogen storage container 1 is inserted with a thermocouple (not shown) for measuring the internal temperature. A general temperature controller using a CPU can be connected to the thermocouple. FIG. 2 is a cross-sectional view of the hydrogen storage container 1 with a cross section taken along a plane perpendicular to the direction A in FIG.

  The honeycomb structure 2 includes a partition part 2a and a lid part 2b. As shown in FIG. 2, the partition 2 a has a lattice shape with a constant cross section perpendicular to the direction A in FIG. 1, and is fitted in the container 4. The cross-sectional shape of the cells of the honeycomb, that is, the voids, is not limited to a square lattice, and may be a polygon such as a triangle, a pentagon, or a hexagon. The dimension and shape of the partition part 2a are determined in consideration of necessary strength, thermal conductivity, air permeability, and the like. The thickness of the wall is preferably 1 mm to 10 mm in consideration of the demand for air permeability and weight reduction. The lid 2 b functions as a filter that passes hydrogen between the gas flow pipe 8 and the hydrogen storage body 3 while holding the hydrogen storage body 3. In addition, although the cover part 2b is provided in the both sides of the partition part 2a in FIG. 1, if only one channel is provided, it is sufficient to provide one on the channel side. In some cases, the hydrogen storage body 3 can be held without the lid 2b.

  The lid portion 2b of the honeycomb structure 2 is formed in a plate shape and seals both ends of the partition portion 2a extending in the A direction. The honeycomb structure 2 is formed of a porous metal having communication holes. Since it is made of metal, the thermal conductivity of the honeycomb structure 2 is improved, and the hydrogen storage body filled in the cells of the honeycomb structure can be heated uniformly. In addition, since the hydrogen storage body is partitioned and partitioned in a honeycomb structure, heat can be efficiently transmitted to the entire hydrogen storage body 3 filled in the honeycomb cells.

  Further, since the metal constituting the honeycomb structure 2 is porous having communication holes, it is possible to improve the hydrogen gas permeability while maintaining high thermal conductivity. The hole diameter of the communication hole is preferably about 10 μm or less, and more preferably 5 μm or less. When the pore diameter is 10 μm or more, the powder particles of the hydrogen storage body 3 easily enter the communication hole and become clogged, which may hinder the smooth flow of hydrogen gas. Moreover, in order to ensure sufficient strength and air permeability, the porosity is preferably 30% to 70%.

The metal constituting the honeycomb structure 2 is not limited as long as it is a metal, and may be two or more kinds of alloys. Examining specific materials, the thermal conductivity of copper is 403 W / m · K, the thermal conductivity of aluminum is 236 W / m · K, and copper and aluminum have high thermal conductivity. The density of aluminum is 2.70 × 10 ⁻³ kg / m ³ , the density of magnesium is 1.74 × 10 ⁻³ kg / m ³ , and aluminum and magnesium are low in density. In view of these excellent characteristics, a metal containing copper, aluminum, or magnesium as a main component is particularly preferable. Furthermore, since the density of copper is as high as 8.96 × 10 ⁻³ kg / m ³ , while the thermal conductivity of magnesium is as low as 157 W / m · K, considering the balance between thermal conductivity and density, Particularly preferred is a metal mainly composed of aluminum.

A hydrogen storage body 3 is filled in the gap of the partition 2a. As a material of the hydrogen storage body 3, La-Ni-based hydrogen storage alloy such as Ti-Cr-V system, a metal hydride such as MgH _2, alanate material such as NaAlH _4, lithium - nitrogen based or lithium - boron system Materials and powder hydrogen storage materials of carbon materials such as carbon nanotubes are used.

  The container 4 accommodates the honeycomb structure 2 and the hydrogen storage body 3 and has an airtight structure. For the container 4, for example, a material and a shape that can withstand a pressure of up to 10 MPa are selected. The material and shape of the container 4 are not particularly limited as long as the material and shape can withstand the pressure when the hydrogen storage body 3 stores hydrogen. Thereby, even if it is a case where the pressure rise by rapid discharge | release is accompanied at the time of hydrogen discharge | release, it is sufficient as intensity | strength of a container and can maintain safety | security. In addition, since the container 4 is heated by a heater, a container with little deformation or alteration is used even when the temperature rises and falls about 300 ° C. repeatedly. In FIG. 2, the outer shape of the container 4 is a quadrangular column with rounded corners. However, for example, when the container 4 is mounted on an automobile, it may have a shape matched to the rear seat in order to eliminate useless space.

  Further, the container 4 may be provided with a safety valve (not shown) set to open at a constant pressure of less than 10 MPa. Such a safety valve may be provided if necessary, but may not be provided. The container 4 may be provided with an entrance / exit mechanism such as an openable / closable entrance / exit through which the hydrogen storage body 3 can be taken in / out. In that case, it is good also as a mechanism in which the hydrogen storage body 3 can be taken in and out of the container 4 by a cartridge type.

  The gas flow port 6 is fixed so that a gas flow tube 8 having a valve 7 communicates with the inside of the container 4. As a heating unit, an electrothermal heater 9 is provided outside the container 4. Thereby, it can be set as a simple structure compared with the structure of the internal heating which passes the inside of a container so that a heat-medium pipe | tube contacts a hydrogen storage body. In addition, since the heating method is not internal heating using a heat medium pipe or the like, there is no inconvenience that the medium leaks when subjected to some impact. A power source (not shown) is connected to the heater 9. The heating unit includes not only a member that heats the hydrogen storage body 3 indirectly from the outside of the container through the container 4 as described above, but also a member for heat conduction connected to the heater 9 in the container 4. In which the hydrogen storage body 3 is indirectly heated by heating the honeycomb structure 2. The heater 9 has a function capable of being heated to a temperature of 80 ° C. or higher, and is preferably capable of being heated to 300 ° C. In order to efficiently store and release hydrogen, the temperature is adjusted to 100 ° C. to 300 ° C. according to the characteristics of the hydrogen storage material used.

  Since the heater 9 is provided in this manner, when the hydrogen storage body 3 is heated by the heater 9, the function of occluding or releasing hydrogen of the hydrogen storage body 3 is activated, so that the hydrogen Occlusion and release can be performed.

  Next, the manufacturing method of the hydrogen storage container 1 is demonstrated. Here, a method for producing a sintered metal will be described as an example. First, a metal powder having an appropriate particle size is prepared so that the communication hole is about 5 μm or less. The method for producing the metal powder is not particularly limited, but for example, it can be produced by mechanical pulverization, electrolysis, reduction, spraying, or the like. In particular, the spray method is suitable not only because it is excellent in mass productivity and economy, but also because the particles become spherical and the ventilation resistance of the produced porous metal is low. Since the pore size is about 15% of the powder particles to be used, metal particles having a particle size of about 40 μm or more are filtered through a mesh.

  Next, the metal powder and the binder are weighed and mixed. A binder having a viscosity suitable for extrusion molding is used. Examples of the binder include organic substances such as methylcellulose, but are not particularly limited as long as an appropriate viscosity can be obtained. The mixture is extruded by an extruder using a honeycomb forming die to obtain a honeycomb-shaped green molded body. A molded product is obtained in the same manner for the plate shape.

  After the green molded body is dried and degreased, sintering is performed in a temperature range of 80% to 95% of the melting point of the metal to be sintered. Degreasing and sintering are performed in an inert gas atmosphere or a reducing gas atmosphere. The sintered porous metal body is shaped, processed and washed according to the shape of the container 4. Thus, the porous metal partition 2a and the lid 2b are obtained.

  The obtained partition portion 2a is fitted into the container 4, and the porous metal lid portion 2b obtained in the same manner is fixed to one end portion of the partition portion 2a. Next, the hydrogen storage body 3 is filled in the gap of the partition 2a, and the other lid 2b is fixed to the other end. Although omitted in FIG. 1, the accommodating portion 4 has an open / close structure in which the honeycomb structure 2 can be inserted and closed in an airtight manner. Next, the honeycomb structure 2 is inserted, a heater is provided to cover the outer side surface of the accommodating portion 4 filled with the hydrogen storage body 3, and the outside is further covered with a heat insulating material 10.

  In the above manufacturing method, the porous metal is produced by the method of producing the sintered metal, but the method of producing the foam metal may be used.

  Next, the operation of the hydrogen storage container 1 will be described. When hydrogen gas is stored in the hydrogen storage container 1, the hydrogen storage body 3 is first heated by the heater 9 and maintained at a temperature at which the hydrogen storage function is sufficiently exhibited. Heat is uniformly transmitted to the hydrogen storage body 3 by the honeycomb structure 2. A compressor (not shown) connected to the gas flow pipe 8 pumps hydrogen gas into the container 4 and stores it in the hydrogen storage body 3 through the communication holes of the honeycomb structure 2. On the other hand, when hydrogen gas is released from the hydrogen storage container 1, first, the hydrogen storage body 3 is heated by the heater 9 via the honeycomb structure 2 and sufficiently maintained at a temperature at which the hydrogen releasing function is exhibited. . Hydrogen gas is released from the hydrogen storage body 3 by heating, and the hydrogen gas is sent to the gas flow pipe 8 through the honeycomb structure 2.

  The hydrogen storage container 1 can be used for a hydrogen supply device mounted on a fuel cell vehicle, a buffer tank for a stationary fuel cell, and a storage container system for a hydrogen station. It can be applied to all hydrogen storage devices.

  In particular, when the hydrogen storage container is mounted on a moving body such as a fuel cell vehicle, a fuel cell vehicle that is light and efficient in storing fuel can be realized. The mobile body on which the hydrogen storage container is mounted is not limited to a fuel cell vehicle, and may be a hydrogen engine vehicle. The mobile body includes vehicles such as automobiles and motorcycles, ships, and airplanes. The above embodiment is an illustration, Comprising: This invention is not limited to these embodiment.

[Embodiment 2]
The honeycomb structure 2 of Embodiment 1 has an average pore diameter of about 5 μm to prevent clogging due to particles of the hydrogen storage body 3, but the average pore diameter of the honeycomb structure 20 is increased as shown in FIG. In addition, you may provide the coating | coated part 21 which has a small diameter communicating hole in the surface. Thereby, the flowability of gas can be improved while preventing the powder particles of the hydrogen storage body 3 from entering the surface of the honeycomb structure and causing clogging.

  Manufacture of the honeycomb structure 2 having such a multilayer structure is performed by adding a process of providing the covering portion 21 of the honeycomb structure to the manufacturing method of the first embodiment. For example, after drying the green molded body of the honeycomb, the surface of the molded body is coated with a solution obtained by adding vinyl chloride to a phenol resin solvent by means such as coating, degreased and sintered. By adding such a process, a carbon layer having small pores of 5 μm or less can be provided on the surface of the honeycomb structure. Instead of vinyl chloride, an easily decomposable material such as styrene foam may be added. Alternatively, a metal powder fine enough to prevent clogging of the hydrogen storage body into the sintered body may be mixed with the organic solvent, and the mixture may be coated on the molded body by means such as coating.

  In addition, the surface of the honeycomb structure 20 after sintering may be coated with a metal or ceramic to provide a covering portion. For example, the coating is performed by wash coating. That is, first, a metal granule of a material that can be fused or reacted below the melting point of aluminum or metal to adhere to the honeycomb body is used, a slurry is prepared using an organic solvent or water, and the honeycomb body is completely immersed. . Thereafter, excess slurry is removed with an air cleaner and compressed air, and after drying, heat treatment is performed at a predetermined temperature. At this time, a metal powder having an appropriate particle size is used so that a layer as the covering portion 21 having a smaller pore diameter than the inside of the honeycomb structure 20 is produced.

  Further, when metal aluminum is used, when the degreasing and sintering are finally performed, the honeycomb structure 20 is formed in an inert atmosphere such as Ar, and then nitrogen is allowed to flow while controlling the temperature. A crystal of aluminum nitride may be intentionally deposited on the surface of the body 20 to control the surface pore size to be small.

[Embodiment 3]
In Embodiment 1, the heater 9 is provided only on the outside of the container 4, but the honeycomb structure 2 may be directly heated by the rod heater 25. As shown in FIG. 4, a rod heater 25 is provided in direct contact with the honeycomb structure 2 in the container. Thereby, since the heater with good heat conductive water is added, the hydrogen storage body 3 can be heated efficiently.

[Embodiment 4]
In Embodiment 1, although the case where the hydrogen storage container 1 was used independently was demonstrated, you may gather the hydrogen storage container according to a required capacity | capacitance using the several hydrogen storage container 30. FIG. As shown in FIG. 5, the hydrogen storage container 30 includes a honeycomb structure 31, a hydrogen storage body 32, a container 33 and a heater 34. In addition, a thermocouple (not shown) is inserted into the hydrogen storage container 30 for measuring the internal temperature. A general temperature controller using a CPU can be connected to the thermocouple. As shown in FIG. 6, the hydrogen storage container 30 in this case is preferably a polygonal column such as a substantially quadrangular prism, a pentagonal column, or a hexagonal column, or an outer shape. Thereby, the several hydrogen storage container 30 can be put in order and used as an aggregate | assembly, and a hydrogen storage apparatus can be produced according to a required capacity | capacitance. In addition, the production cost can be reduced by mass production as a unit. In particular, a triangular prism, a quadrangular prism, and a hexagonal prism are suitable for mass production because they can fill a space with the same shape.

  As shown in FIG. 5, when a plurality of hydrogen storage containers 30 are used, the heat insulating material may be omitted from the hydrogen storage container as one unit. Thereby, if the hydrogen storage container 30 is used in close contact, the efficiency of heat conduction can be increased. The dimensions of the hydrogen storage container 30 are, for example, 30 cm × 30 cm × 150 cm, and a plurality of these are combined to form an integrated hydrogen storage container. As a result, it is possible to design a large mobile body or industrial hydrogen storage container according to the required capacity or constrained shape, and an efficient hydrogen storage assembly can be configured.

  As shown in FIG. 7, a plurality of hydrogen storage containers 30 may be collectively used as the hydrogen storage device 40. The hydrogen storage device 40 includes an assembled hydrogen storage container 30 and a heat insulating material 41 covering the outside thereof, and each hydrogen storage container 30 is connected to a connecting pipe 44 through a valve 42 and a gas flow pipe 43. The gas flow pipe 43 and the connecting pipe 44 form a flow path as a flow path forming portion. Further, the hydrogen storage device 40 is provided with a temperature control unit (not shown) that performs unified temperature control of the heating unit of each hydrogen storage container. In FIG. 7, a general temperature controller using a CPU can be used as the temperature control unit of the hydrogen storage device 40. The temperature inside the storage container is measured by a thermocouple inserted inside. In addition, a collective flow path is secured for taking hydrogen into and out of each hydrogen storage container. In order to make a flow path, each hydrogen storage container 30 is accommodated in a single large container, for example. In this way, a hydrogen storage device in which a plurality of hydrogen storage containers are combined can be configured. As a result, a plurality of hydrogen storage containers 30 can be collectively assembled and controlled as a hydrogen storage device, and a large capacity of hydrogen can be taken in and out efficiently. In addition, it is possible to manufacture an efficient hydrogen storage device at low cost compared to manufacturing a large-capacity hydrogen storage device.

It is sectional drawing which shows 1st Embodiment of the hydrogen storage container which concerns on this invention. It is sectional drawing which shows 1st Embodiment of the hydrogen storage container which concerns on this invention. It is sectional drawing of the honeycomb structure which provided the coating | coated part on the surface. It is sectional drawing which shows 3rd Embodiment of the hydrogen storage container which concerns on this invention. It is sectional drawing of the hydrogen storage container used collectively. It is a schematic perspective view of the hydrogen storage container used collectively. It is a schematic perspective view of a hydrogen storage device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen storage container 2 Honeycomb structure 2a Partition part 2b Cover part 3 Hydrogen storage body 4 Container 9 Heater (heating part)
DESCRIPTION OF SYMBOLS 10 Heat insulating material 20 Honeycomb structure 21 Covering part 30 Hydrogen storage container 31 Honeycomb structure 32 Hydrogen storage body 33 Container 34 Heater 40 Hydrogen storage apparatus 41 Heat insulating material

Claims (4)

A honeycomb structure composed of a porous metal having communication holes;
A hydrogen storage body filled in the voids of the honeycomb structure;
A container for housing the honeycomb structure and the hydrogen storage body;
A hydrogen storage comprising: a heating unit that indirectly heats the hydrogen storage body from outside the container or indirectly heats the hydrogen storage body by heating the honeycomb structure. container.   The hydrogen storage container according to claim 1, further comprising a covering portion having a communication hole having a diameter smaller than an average hole diameter of the honeycomb structure on a surface of the honeycomb structure.   The hydrogen storage container according to claim 1 or 2, wherein the outer shape is formed in a substantially polygonal column. A hydrogen storage device comprising a plurality of hydrogen storage containers according to any one of claims 1 to 3,
A temperature control unit for uniformly controlling the temperature of the heating unit of each hydrogen storage container;
A hydrogen storage device, comprising: a flow path forming unit that forms a flow path for flowing hydrogen through each of the hydrogen storage containers.

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