JPS6332721B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to metal hydride reactors.

It is known that certain metals and alloys reversibly absorb and release hydrogen. Hydrogen storage is an exothermic reaction, and hydrogen release is an endothermic reaction. Heat pumps, hydrogen storage devices, hydrogen purification devices, chemical engines, etc. that utilize the characteristics of such metal hydrides have been proposed.

In these metal hydride devices, the metal hydride undergoes a hydrogen absorption/desorption reaction in a closed container, but the reaction rate is regulated by hydrogen diffusion and heat conduction. The metal hydride expands, contracts, and becomes a fine powder due to hydrogen absorption and release, and is densely packed, making it impossible for hydrogen to flow smoothly into the metal hydride layer, and reducing the heat conduction of the metal hydride layer due to the fine powder formation. I had a problem.

In order to solve the above problems, the inventors previously installed heat transfer fins inside a tubular container and a porous tube for hydrogen diffusion in the center, as shown in Utility Application No. 56-40879. However, the porous tubes may collapse due to the expansion of the metal hydride, inhibiting hydrogen flow, and although heat transfer fins improve heat conduction, The limited amount of hydride charged and the large heat capacity of the heat transfer fins were disadvantageous for heat pumps.

The inventor of the present invention did not transfer heat between the metal hydride and the heating medium through the container wall of the filled container, but arranged a heating medium tube group consisting of a large number of flexible thin tubes in the metal hydride layer. In addition, a group of flexible tubular permeable bodies is used so that the permeable body for hydrogen flow is not crushed or is partially crushed so that hydrogen can flow through it. The idea of forming a hydrogen flow path led to the invention.

The gist of the present invention is to provide a group of heat medium tubes that are filled with a metal hydride inside a closed container and are made up of a large number of flexible thin tubes, and a large number of flexible tubes that allow hydrogen to pass through but not the metal hydride. The metal hydride reactor is characterized in that a group of hydrogen permeable bodies comprising tubular permeable bodies are positioned between each other in a metal hydride layer.

An example of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a closed container,
It has a substantially cylindrical cross section, and both ends 2 and 3 are sealed. 4 and 5 are support plates for supporting the thin tube group within the closed container 1. Reference numerals 6 and 6 denote hydrogen flow joints, which are supported by the support plate 4. 7, 7 are heat medium flow joints, which are supported by the support plate 5.

A group of 8 flexible tubular permeable bodies is provided between the hydrogen flow joints 6, 6. The transparent body 8 has a flexible tubular shape, and has an inner diameter of 2 to 2.
A porous tube having a diameter of about 20 mm and having a large number of small pores with a diameter of 1 to 5 μm in the tube wall is preferred. Examples of the material for the transparent body 8 include porous molded products of synthetic resins such as fluororesin, sintered synthetic resins, nonwoven fabrics of metal fibers or carbon fibers, and the like.

The permeable body 8 is dispersed almost uniformly within the closed container 1. The inner diameter of the tubular transparent body 8 is 2
If the inner diameter is less than 20 mm, the hydrogen flow resistance becomes large, and if the inner diameter exceeds 20 mm, the permeable body 8 tends to be crushed by the expansion and compression of the metal hydride. Transparent body 8
If the diameter of the small pores is less than 1μ, the resistance to permeation and diffusion of hydrogen will be large, and if it exceeds 5μ, fine powder metal hydride will be able to permeate.

An example of a large number of groups of 8 transparent bodies is shown in FIG.
The heat medium tube 9 group consisting of a large number of flexible thin tubes has an appearance similar to the transparent body 8 group shown in FIG. 3, but is not porous. The heat medium tubes 9 are distributed almost uniformly in the closed container 1, and the heat medium tubes 9 are positioned between the transparent bodies 8, 8. A finely powdered metal hydride 10 is filled between the 8 groups of transmitting bodies and the 9 groups of heat medium tubes. The heat medium tube 9 is flexible and preferably highly elastic, and is made of polyethylene, polypropylene, vinyl chloride resin, fluororesin, or the like. These synthetic resins have the advantage that impurities in the heat medium do not adhere to them. The elasticity of the heat medium tube 9 absorbs the expansion and contraction of the metal hydride 10, and the flexibility of the heat medium tube 9 prevents it from being destroyed by pressure caused by the expansion and contraction of the metal hydride 10. The inner diameter of the heat medium tube 9 is 2 mm or more in order to reduce the flow resistance of the heat medium, and the metal hydride 1
In order to prevent collapse due to zero expansion and contraction, the diameter is preferably 20 mm or less.

It is better for the 8 groups of hydrogen permeable bodies and the 9 groups of heat medium pipes to be thin and large in number, apart from hydrogen flow resistance and heat medium flow resistance. This is because the hydrogen diffusion rate from the hydrogen permeable body 8 to the metal hydride 10, the heating medium and the metal hydride 10
In order to increase the heat conduction speed between the hydrogen diffusion and heat conduction distances, it is better to have a small distance, and the distance between the hydrogen permeable bodies 8 and the distance between the heat medium pipes 9 and 9 are preferably 1 to 1. Made in 50mm.

FIGS. 4 and 5 show another example of the present invention.

Support plates 4,
Heat medium flow joints 7, 7 are supported on the support plate 4, respectively, and a hydrogen inlet/outlet joint 11 is further supported on the support plate 4.

The hydrogen permeable bodies 8a of the group of hydrogen permeable bodies 8a are different from the permeable bodies 8 shown in FIGS. 1 to 3 in that one end thereof is sealed. When two metal hydride reactors of the present invention are connected to transfer and exchange hydrogen to form a heat pump device, the group of hydrogen permeable bodies 8a in FIG. can be made possible.

Further, a heat insulating material layer 12 such as synthetic resin foam or asbestos is provided between the metal hydride 10 layer and the inner wall surface of the closed container 1 to insulate the metal hydride 10 and the closed container 1 from heat. By providing the heat insulating material layer 12, the heat generated by the metal hydride 10 is transferred to the closed container 1.
The heat is not transmitted to the heat medium, but is transmitted to the heat medium flowing through the group of heat medium pipes 9, thereby reducing heat loss.

The metal hydride reactor of the present invention has the above-mentioned configuration and exhibits the effects described below.

Since the distance between the heating medium and the metal hydride is shortened, heat conduction between the two becomes good, and the hydrogen absorption/desorption reaction of the metal hydride can proceed rapidly.

Since the heat medium tube group consisting of a large number of thin tubes is distributed and located in the metal hydride layer, the temperature distribution of the metal hydride layer becomes uniform, and the hydrogen absorption/desorption reaction can proceed uniformly.

Since the hydrogen permeable body group consisting of many permeable bodies is located in the metal hydride layer, hydrogen diffusion from the hydrogen permeable body to the metal hydride occurs rapidly, and the hydrogen absorption/desorption reaction rate of the metal hydride is reduced. Becomes large.

Since a large number of flexible heat medium tube groups and flexible hydrogen permeable body groups exist in the metal hydride layer, expansion and contraction of the metal hydride is absorbed.
No force is applied to the wall of the sealed container, preventing deformation and damage, and reducing the thickness of the wall of the sealed container.

As mentioned above, the sealed container does not require pressure resistance and the reaction of the metal hydride layer can be carried out uniformly, so it is possible to fill the sealed container with a large amount of metal hydride, simplifying the device structure and operation. be able to.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the metal hydride reactor of the present invention, FIG. 2 is a longitudinal sectional view cut away along the line of FIG. 1, and FIG. 3 is a plan view showing an example of a hydrogen permeable group. FIG. 4 is a longitudinal sectional view showing another example of the metal hydride reactor of the present invention, and FIG. 5 is a longitudinal sectional view taken along the line of FIG. 4. 1 is a closed container, 8 and 8a are hydrogen permeable bodies, 9 is a heating medium tube, and 10 is a metal hydride.

Claims (1)

[Claims] 1 A group of heat medium tubes filled with a metal hydride inside a closed container and consisting of a large number of flexible thin tubes, and a large number of flexible tubular permeable bodies that allow hydrogen to pass through but not the metal hydride. A metal hydride reactor, characterized in that a group of hydrogen permeable bodies consisting of the following are located between each other in a metal hydride layer.