JPH0159202B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a metal hydride container suitable for storing and extracting heat using a metal hydride.

(b) Prior art Certain metals or alloys react reversibly with hydrogen, and attempts are currently being made to utilize the heat of reaction generated at this time for heat storage, etc. Various proposals for chemical containers have been made.

However, conventional metal hydride containers of this type have a configuration in which heat exchange is performed between the metal hydride and the heating medium via a heat pipe, which increases sensible heat loss and The disadvantage is that the heat transfer resistance between the heat transfer medium and the heat medium increases, and the heat transfer rate decreases.

Therefore, in order to eliminate such drawbacks of the prior art, the applicant provided a heat medium pipe through which a heat medium flows through a pressure vessel with a hydrogen inlet/output pipe, and a heat insulating material that allows hydrogen to pass through the inside of the pressure vessel. cover the surroundings,
A cylindrical tube having filters at both ends that allows hydrogen to pass through but not metal hydride is provided on the heat medium tube,
We have proposed a metal hydride container in which a plurality of fins are arranged along the tube axis between the cylindrical tube and the heat medium tube to divide the interior, and metal hydride is stored in each space. (See Japanese Patent Application No. 59-197775 (Japanese Unexamined Patent Publication No. 61-76887)). According to this container configuration, heat transfer loss and sensible heat loss are significantly reduced, and a metal hydride container with extremely high thermal efficiency can now be obtained. However, in the above-mentioned metal hydride container, if even a small amount of moisture or organic components are mixed into the heat insulating material that coats the inner surface of the pressure-resistant container, the metal hydride will be poisoned and the heat storage and extraction capacity will be reduced. There was a problem that the performance decreased. for example,
La in the activated LaNi ₅ alloy reacted violently with water, forming oxides or hydroxides on the alloy surface, which significantly inhibited hydrogenation and dehydrogenation of the alloy.

(C) Problems to be Solved by the Invention The present invention solves the above problems and further improves the container structure previously proposed by the applicant, so that the ability to store and extract heat is stable over a long period of time. Moreover, it is an object of the present invention to provide a metal hydride container with good heat exchange efficiency and less sensible heat loss to the pressure-resistant container.

(d) Means for Solving the Problems The metal hydride container of the present invention is capable of eliminating moisture and organic components mixed into the insulation material during molding and storage by subjecting the insulation material that covers the heat exchanger to heat treatment in advance. In addition to removing the heat-insulating material, the surface of the heat-insulating material is coated with a coating having excellent heat-insulating properties.

(E) Effect Since water and organic components that cause poisoning are removed in advance from the insulation provided inside the container, the metal hydride is not poisoned and its heat storage and extraction ability is stable over a long period of time. will be maintained. In addition, since the surface of the insulation material is coated with a film that does not allow hydrogen to pass through, almost no hydrogen flows into the insulation material, and hydrogen convection within the insulation material reduces the transmission between the heat exchanger and the pressure vessel. Heat is suppressed and high heat exchange efficiency is obtained.

(F) Embodiments Below, embodiments shown in the drawings will be described in detail.

FIG. 1 shows a configuration diagram of a metal hydride container according to an embodiment of the present invention, and a is a side view thereof;
b is a front sectional view, and c is a side sectional view. In these figures, reference numeral 1 denotes a pressure-resistant container, which has a hydrogen inlet/output conduit 1a for introducing and removing hydrogen, and a flange portion 1b for airtightly enclosing a heat insulating material and a heat exchanger, which will be described later, inside the container. A heat medium pipe 3 is disposed that passes through the pressure vessel 1 in an airtight manner, into which the heat medium 2 flows. A cylindrical tube 4 is coaxially disposed in a portion of the heat medium tube 3 that exists inside the pressure vessel. Both ends of this cylindrical tube, excluding the heat medium tube 3, are closed with filters 5a and 5b that allow hydrogen to pass through but not metal hydride fine powder. The mesh size of the filters 5a, 5b is preferably about several microns. Furthermore, between the cylindrical tube 4 and the heat medium 2, as shown in FIG. is divided into multiple areas. Further, metal hydride 7 is stored in each of these areas.

Between the cylindrical tube 4 and the outer pressure vessel 1, there is a heat insulating material 9 such as glass wool whose surface is coated with a heat insulating film 8 that does not allow hydrogen to pass through. The heat insulating materials 10a and 10b that are not present are filled.

FIG. 2 shows the heat insulating material 9 coated with the heat insulating film 8, in which a is a side sectional view and b is a sectional perspective view taken along the line B-B'. The heat insulating material 9 is heat-treated before being installed in the pressure container 1 to remove moisture and organic components that may cause poisoning by the metal hydride 7 mixed into the heat insulating material during molding or storage. The heat treatment temperature at this time is preferably about 500 to 1000° C. when an inorganic fiber material heat insulating material whose main components are alumina and silica, such as Kao Wool (trade name), is used as the heat insulating material 9. At this temperature, moisture and organic components can be removed without changing the quality of the material. Furthermore, the heat-treated insulation material 9 is immersed in a fluorine-based resin such as trifluoroethylene or a liquid curing agent whose main component is silicic acid anhydride, and then heat-treated to aerate hydrogen into the surface of the insulation material 9. It is possible to form a heat-insulating film 8 that does not have any heat-insulating properties.

As will be clear from the description below, the portion surrounded by the cylindrical tube 4 constitutes a heat exchanger, and this heat exchanger can be easily constructed as shown in FIGS. 3 to 5. That is, the perspective view of FIG. 3a,
As shown in the front view of b, first, for example, 4
The heat transfer pipe 3 to which the fins 6 are attached is integrally formed by extrusion molding of aluminum alloy or the like. Similarly, as shown in the perspective view of FIG. 4a and the front view of FIG. 4b, a cylindrical tube 4 with, for example, four fins 6 attached inside the tube is integrally formed by extrusion molding of an aluminum alloy. The heat medium tube 3 and cylindrical tube 4 thus formed are combined as shown in FIG. 5 to constitute a metal hydride storage area. At this time, in order to firmly fix each fin 6 between the heat medium pipe 3 and the cylindrical pipe 4, the inner surface of the cylindrical pipe 4 has a fin fitting groove 4a.
It is good to set up Furthermore, a filter 5 is attached to both ends of the cylindrical tube 4 except for the heat medium tube 3 portion, and a metal hydride is installed inside the cylindrical tube 4, that is, in each area between the heat medium tube 3 and the cylindrical tube 4 partitioned by the fins 6. 7 to form a heat exchanger.

Furthermore, the periphery of the heat exchanger portion configured in this manner is covered with heat insulating materials 9, 10a, and 10b to form the pressure vessel 1.
A metal hydride container is constructed by housing the metal hydride inside and airtightly sealing the inside of the container with the flange portion 1b with the heat medium tubes 3 protruding from both ends of the container.

With the above configuration, the heat of the heat medium 2 flowing through the heat medium pipe 3 is transferred to the metal hydride 7 via the fins 6 during heat storage. Hydrogen is released from the metal hydride 7 by this heat, and the released hydrogen is further passed through the filter 5.
At this time, hydrogen discharged from the filter 5a side passes through the insulation material 10a, and hydrogen discharged from the filter 5b side passes through the insulation material 10b from the gap between the coating 8 and the cylindrical pipe 4. The filter 11 installed in the hydrogen inlet/output pipe 1a
The hydrogen gas is led out of the container and stored in a hydrogen cylinder (not shown).

On the other hand, during heat dissipation, hydrogen is introduced into the pressure vessel 1 from a cylinder (not shown) through the filter 11 of the hydrogen inlet/output pipe 1a. The hydrogen is introduced into the cylindrical tube 4 from the heat insulating material 10a through the filter 5a or through the gap between the coating 8 and the cylindrical tube 4 through the heat insulating material 10b and the filter 5b. The heat generated when this hydrogen is absorbed by the metal hydride 7 is transmitted from the fins 6 to the heat medium 2 flowing in the heat medium pipe 3, and taken out to the outside for use.

Therefore, according to the above configuration, the inside and outside of the cylindrical tube 4 are communicated through the filters 5a and 5b, and as a result, the pressure resistance of the cylindrical tube 4 is not required, so that the thickness of the material of the heat exchanger portion can be minimized. It can be made thinner. As a result, the number of fins 6 provided between the heat medium pipe 3 and the cylindrical pipe 4 can be increased, and the contact area with the fins 6 can be increased without reducing the volume of the metal hydride 7. Thereby, the heat transfer rate between the metal hydride 7 and the heat medium 2 can be greatly improved. Also,
As a result of direct heat exchange between the metal hydride 7 and the heating medium 2 without going through a heat pipe as in the past, heat transfer resistance and sensible heat loss are reduced compared to the past, and the heat transfer rate and heat exchange efficiency are improved. Greatly improved.

In addition, since the periphery of the cylindrical portion of the heat exchanger is covered with a heat insulating material 9 coated with a heat insulating coating 8, the cylindrical tube 4, which is the outer wall of the heat exchanger, and the pressure vessel 1
As well as heat conduction between the inner wall and the heat insulating material 9, since hydrogen does not flow inside the heat insulating material 9, sensible heat loss of reaction heat due to convective heat transfer of hydrogen from the cylindrical tube 4 to the pressure vessel 1 is significantly suppressed. Ru. Furthermore, insulation materials 9, 10
By completely removing moisture and organic components from a and 10b by heat treatment before storing them in the pressure-resistant container 1, there is no risk of poisoning of the metal hydride 7, and the ability to store and extract heat can be maintained for a long time. A metal hydride container that is stable and has good heat exchange efficiency can be obtained.

Incidentally, the heat insulating materials 10a and 10b may also be provided with a heat insulating coating on their surfaces, and the hydrogen may be taken in and out from the filters 5a and 5b into and out of the cylindrical tube 4 through a gap between the coating 8 and the cylindrical tube 4.

Furthermore, the hydrogen inlet/outlet conduit 1a may also be provided on the lid side.

Further, as the material for the pressure vessel 1, it is preferable to use stainless steel (for example, SUS304, SUS316, etc.), which has a low risk of embrittlement even in a high-pressure hydrogen atmosphere.

In addition, the portion of the heat transfer pipe 3 disposed in the cylindrical tube 4 is constructed using a material with good thermal conductivity, while the portion disposed outside the cylindrical tube 4 is constructed using a material with low thermal conductivity. , heat loss from the contact portion between the heat medium pipe 3 and the pressure vessel 1 to the pressure vessel 1 can be further reduced.

(G) Effects of the Invention As described above, according to the present invention, the wall thickness of the heat exchanger portion can be reduced, so the number of fins inside the heat exchanger can be increased without reducing the amount of metal hydride. This makes it possible to increase the contact area between the metal hydride and the fins. Moreover, the heat exchange between the metal hydride and the heating medium is
This is done directly without going through a heat pipe like in the past, reducing sensible heat loss and greatly improving heat exchange efficiency.

In addition, the organic components and moisture in the insulation material that cause metal hydride poisoning are removed by heat treatment in advance, and the coating on the surface of the insulation material transfers the reaction heat due to convective heat transfer of hydrogen from the heat exchanger to the pressure vessel. Since sensible heat loss is suppressed, a metal hydride container with stable heat storage and extraction ability over a long period of time and good heat exchange efficiency can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a metal hydride container according to an embodiment of the present invention, in which a is a side view and b is a side view of the container.
A' is a sectional view, c is a side sectional view, FIG. 2 is an explanatory view of the heat insulating material in FIG. FIG. 4 is an explanatory diagram of a heat medium tube constituting the heat exchanger of FIG. 1, where a is a perspective view thereof, b is a front view thereof, and FIG. a is its perspective view,
b is a front view thereof, and FIG. 5 is a front view of the heat exchanger main body portion constructed by combining FIGS. 3 and 4. 1... Pressure resistant container, 2... Heat medium, 3... Heat medium pipe,
4... Cylindrical tube, 5a, 5b, 11... Filter,
6...Fine, 7...Metal hydride, 8...Coating, 9, 10a, 10b...Insulating material.

Claims (1)

[Scope of Claims] 1. A cylindrical pipe is arranged coaxially with a heat medium pipe through which a heat medium flows, and a plurality of fins are arranged along the axial direction between the cylindrical pipe and the heat medium pipe. Divide into areas and store metal hydride in each area,
Both ends of the cylindrical tube, excluding the heat medium tube, are closed with filters that allow hydrogen to pass through to form a heat exchanger section, and this heat exchanger section is a heat insulating material made of an inorganic material that has been heat-treated to remove moisture and organic components. 1. A metal hydride container, characterized in that the metal hydride container is housed in a pressure-resistant container with a hydrogen inlet/output conduit via the pressure-resistant container, and is sealed with the heating medium tubes airtightly protruding from both ends of the pressure-resistant container. 2. The metal hydride according to claim 1, wherein the surface of the heat insulating material is coated with a heat insulating film to prevent heat transfer from the heat exchanger to the pressure vessel due to hydrogen convection. container.