JP2957515B2 - Hydrogen storage alloy container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen storage alloy container for filling a hydrogen storage alloy, and a hydrogen gas utilization system constituted by connecting a pair of containers storing the hydrogen storage alloy to each other. .

[0002]

2. Description of the Related Art In recent years, a hydrogen gas utilizing system, such as a heat pump, an air conditioner, and an actuator, which utilizes a hydrogen gas storage function of a hydrogen storage alloy and a thermal energy conversion function accompanying hydrogen absorption and release, has been developed. As shown in FIG. 3, these hydrogen gas utilization systems basically include a pair of hydrogen storage alloy containers (10) (1) filled with a hydrogen storage alloy.
0) are connected to each other by a hydrogen gas storage / discharge tube (5), and each hydrogen storage alloy container (10) is provided with a heat medium pipe (30) for heating or cooling the hydrogen storage alloy. ing.

FIG. 2 shows a specific structure of a conventional hydrogen storage alloy container (11), in which a hydrogen gas storage / discharge tube (5) is connected to a cylinder (1) having a closed structure. The inside of the cylindrical body (1) is filled with a powdery hydrogen storage alloy (2), and a heating medium pipe (30) reciprocates a plurality of times in the hydrogen storage alloy (2). The two ends thereof have a heat medium inlet (31) and a heat medium outlet (32) protruding outside from the cylindrical body (1). Also, cylindrical
Inside (1), a plurality of heat transfer fins (4) through which a heat medium pipe (30) penetrates are arranged at regular intervals in the tube axis direction. In the conventional hydrogen storage alloy container (11),
In the heat medium pipe (30), the inlet pipe part (3a) through which the heat medium flows first
And the outlet pipe section (3b) through which the heat medium flows last is located at the maximum separation position in the cylindrical body (1).

In the hydrogen storage alloy container (11), hot water is supplied from the heat medium inlet (31) to the heat medium pipe (30), whereby the hydrogen storage alloy (2) is heated, and the hydrogen storage alloy (2) is heated. )
The hydrogen inside is released. Conversely, by supplying cold water from the heat medium inlet (31) to the heat medium pipe (30), the hydrogen storage alloy
(2) is cooled, and hydrogen is absorbed in the hydrogen storage alloy (2). Therefore, as shown in FIG. 3, a pair of hydrogen storage alloy containers (11) and (11) connected to each other through a hydrogen gas storage / release pipe (5).
Of these, by heating one and simultaneously cooling the other, hydrogen gas moves from one to the other, and then, by reversing the cooling and heating, the hydrogen gas moves in the opposite direction. Here, two kinds of alloys having different equilibrium hydrogen pressures are adopted as a hydrogen storage alloy to be filled in one hydrogen storage alloy container (11) and a hydrogen storage alloy to be filled in the other hydrogen storage alloy container (11). Then, a thermal cycle is constituted by the reciprocating movement of the hydrogen gas.

[0005]

In a hydrogen gas utilization system using the above-mentioned hydrogen storage alloy container (11), the hydrogen storage alloy expands into a hydrogen storage alloy as the hydrogen storage alloy absorbs and releases hydrogen in the above-described heat cycle. Shrinkage occurs, which causes repeated stress to act on the hydrogen storage alloy container (11). In particular, the inlet (3a) of the inlet pipe (3a) of the heat medium pipe (3) to which cold water is supplied.
1) In the vicinity, since the temperature of cold water is low, the reaction speed of the hydrogen storage alloy is high, and excessive stress is generated due to local expansion of the hydrogen storage alloy due to hydrogen absorption. As a result, there is a problem that the hydrogen storage alloy container (11) is deformed and further broken.

An object of the present invention is to alleviate the repetitive stress acting on a hydrogen storage alloy container due to the absorption and release of hydrogen and to prevent deformation and breakage of the hydrogen storage alloy container.

[0007]

A hydrogen storage alloy container according to the present invention comprises a cylinder (1) to which a hydrogen gas absorption / desorption tube (5) is connected. A storage chamber for the storage alloy is formed, and a heat medium pipe (3) is provided, which is formed by directly connecting a plurality of pipe sections extending in the same direction in the storage chamber. Both ends of the heat medium pipe (3) project out of the cylinder (1) to have a heat medium inlet (31) and a heat medium outlet (32). Here, among a plurality of pipes constituting the heat medium pipe (3), the inlet pipe (3a) through which the heat medium flows first and the outlet pipe (3b) through which the heat medium flows last are adjacent to each other. doing.

Further, the hydrogen gas utilization system according to the present invention is characterized in that the hydrogen storage alloy container of the present invention is provided with a hydrogen gas storage / discharge tube.
(5) are connected to each other.

In the above hydrogen storage alloy container of the present invention,
The coolant as a heat medium flowing into the heat medium inlet (31) flows through the heat medium pipe (3) and then flows out of the heat medium outlet (32). Cool the storage alloy. Thereby, the hydrogen storage alloy absorbs hydrogen and expands. In addition, since the coolant flows through the heat medium pipe (3) while performing heat exchange with the hydrogen storage alloy that generates heat by absorbing hydrogen, the temperature of the coolant is lowest at the inlet pipe part (3a) of the heat medium pipe (3). , Outlet piping
(3b) has the highest temperature.

[0010] In the conventional hydrogen storage alloy container, the inlet pipe section (3a) and the outlet pipe section (3b) of the heating medium pipe are disposed separately, and the inlet pipe section (3a) and the outlet pipe section (3) are arranged. While heat exchange hardly takes place during 3b), in the hydrogen storage alloy container of the present invention, the inlet pipe section (3a) and the outlet pipe section (3b)
Are located adjacent to each other, sufficient heat transfer is performed between the outlet pipe section (3b) and the inlet pipe section (3a),
The temperature difference of (3a) and (3b) is reduced. As a result,
Excessive stress due to local expansion of the hydrogen storage alloy, which has conventionally occurred near the inlet (31) of the inlet pipe (3a), is suppressed.

[0011]

In the hydrogen storage alloy container and the hydrogen gas utilization system using the same according to the present invention, a heating medium pipe is provided.
With the configuration in which the inlet pipe section (3a) and the outlet pipe section (3b) of (3) are arranged close to each other, the repetitive stress acting on the hydrogen storage alloy container due to hydrogen absorption and release is reduced, and as a result,
The hydrogen storage alloy container is prevented from being deformed or broken.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows the structure of a hydrogen storage alloy container (10) according to the present invention.
1 schematically shows a hydrogen gas utilization system constituted by connecting a pair of hydrogen storage alloy containers (10) and (10) with a hydrogen gas storage / discharge tube (5).

As shown in FIG. 1, the hydrogen storage alloy container (10)
A cylinder (1) having a closed structure is provided, and a hydrogen gas absorption / desorption tube (5) is connected to the cylinder (1). The inside of the cylindrical body (1) is filled with a powdery hydrogen storage alloy (2), and a heating medium pipe (3) reciprocates a plurality of times in the hydrogen storage alloy (2). The two ends thereof have a heat medium inlet (31) and a heat medium outlet (32) protruding outside from the cylindrical body (1). Here, the heating medium pipe (3) is, as shown in the figure, an inlet pipe section (3a) through which the heating medium flows first among a plurality of pipe sections extending in parallel with each other, and is a cylindrical body (1).
After extending horizontally at the upper corner of the cylinder, it reciprocates in the cylinder (1), reaches the lower corner of the cylinder (1), and then returns to the return pipe (3).
Returning again to the upper part of the cylindrical body (1) through c), the outlet pipe (3b) through which the heat medium finally flows is adjacent to the inlet pipe (3a) and in the opposite direction to the inlet pipe (3a). Is growing. A plurality of heat transfer fins through which a heat medium pipe (3) penetrates are provided inside the cylindrical body (1).
(4) are arranged at regular intervals in the tube axis direction.

In the hydrogen storage alloy container (10), hot water is supplied from the heat medium inlet (31) to the heat medium pipe (30), whereby the hydrogen storage alloy (2) is heated, and the hydrogen storage alloy (2) is heated. )
The hydrogen inside is released from the hydrogen gas absorption / desorption tube (5). Conversely, by supplying cold water from the heat medium inlet (31) to the heat medium pipe (30), the hydrogen storage alloy (2) is cooled, and the hydrogen supplied from the hydrogen gas storage / release pipe (5) is used to store hydrogen. Absorbed in alloy (2). Therefore, as shown in FIG. 4, in a hydrogen gas utilization system in which a pair of hydrogen storage alloy containers (10) and (10) are connected to each other by a hydrogen gas storage and release tube (5), one of the hydrogen storage alloy containers (10) is used. By heating and simultaneously cooling the other hydrogen storage alloy container (10), hydrogen gas moves from one hydrogen storage alloy container (10) to the other hydrogen storage alloy container (10), and then cooling and heating are performed. By reversing, the hydrogen gas moves in the opposite direction. The hydrogen storage alloy to be filled in one hydrogen storage alloy container (10) and the hydrogen storage alloy to be filled in the other hydrogen storage alloy container (10) have different equilibrium hydrogen pressures. .

In the hydrogen storage alloy container (10), since the inlet pipe (3a) and the outlet pipe (3b) are arranged adjacent to each other, the outlet pipe (3b) and the inlet pipe (3a) are arranged adjacent to each other. ), The temperature difference between the inlet pipe section (3a) and the outlet pipe section (3b) is reduced, and local volume expansion of the hydrogen storage alloy is suppressed. As a result, the repetitive stress acting on the hydrogen storage alloy container is reduced, and the deformation and destruction of the hydrogen storage alloy container are prevented.

In order to demonstrate the effect of the hydrogen storage alloy container (10) of the present invention, the inventors have studied the heat transfer between the inlet pipe (3a) and the outlet pipe (3b) of the heat medium pipe (3). The effect of the transfer on the reaction of the hydrogen storage alloy was examined by computer simulation, and the relationship between the volume expansion of the hydrogen storage alloy and the stress acting on the cylinder (1) was examined by experiments.

Simulation In order to quantitatively grasp the reaction rate distribution in the alloy vessel that causes local volume expansion, a model divided in the flow direction of the heat medium as shown in FIG. Alloy container
(11) Between (11), a hydrogen storage alloy reaction simulation using a plurality of basic formulas shown in the following equation 1 was performed.

[0018]

(Equation 1)

Here, an empirical formula obtained by a separate experiment was used as the alloy reaction rate equation, and a PCT curve characteristic fitting model equation was adopted as the alloy characteristic equation, and the reaction characteristics were analyzed by a time difference method.

Further, in order to grasp the relationship between the structure of the hydrogen storage alloy container (10) of the present invention and the local reaction rate distribution, FIG.
A model as shown in Fig. 3 was created and two hydrogen storage alloy containers (1
Changes in the local reaction rate due to the heat transfer coefficient HA between 0 and (10) (HA = heat transfer amount Q / temperature difference ΔT) were analyzed.

FIG. 5 shows that n =
5 is a graph showing the effect of the heat transfer coefficient HA on the temporal change of the hydrogen storage amount in the cell No. 1. From this graph, when HA = 0 (corresponding to the model in FIG. 3), H
In the case of A> 0 (corresponding to the model in FIG. 4), it can be seen that the local increase in the amount of hydrogen storage is alleviated with the increase in HA. In particular, at the point where the effective hydrogen transfer amount is 0.8 wt%, the increase in the hydrogen storage amount is greatly reduced when HA is 20 (W / K), and is reduced when HA is 50 (W / K) or more. Effect is reduced.

From these results, it can be seen that the inlet pipe portion of the heat medium pipe (3)
(3a) and the outlet pipe section (3b), the heat transfer coefficient between both pipe sections is 2
It can be said that by setting the interval at about 0 (W / K) or more, local expansion of the hydrogen storage alloy can be greatly reduced.

Experiment In the experiment, a cylindrical hydrogen storage alloy container (10) having an outer diameter of 18 mm and a thickness of 1 mm was placed horizontally, and a hydrogen absorption / desorption cycle was performed. Was measured. FIG. 6 is a graph showing the stress of each cell of the hydrogen storage alloy container (10) using the heat transfer coefficient HA as a parameter. As is clear from this graph, HA =
In the case of 0 (corresponding to the model in FIG. 3), the maximum stress greatly exceeds the allowable stress of stainless steel or copper, whereas HA>
In the case of 0 (corresponding to the model in FIG. 4), the maximum stress is relaxed with an increase in HA, for example, when HA is 20 (W / W /
The maximum stress in the case of K) is lower than the allowable stress of stainless steel.

From these results, it can be seen that the inlet pipe portion of the heat medium pipe (3)
(3a) and the outlet pipe part (3b) are arranged adjacent to each other, and the heat transfer coefficient between the two pipe parts is set to about 20 (W / K) or more, so that the cylindrical body (1) is formed. It can be said that the acting stress can be remarkably reduced, and the deformation and destruction of the stainless steel or copper cylinder (1) can be prevented.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, the outlet pipe section of the heat medium pipe (3)
Not only the structure in which only (3b) is adjacent to the inlet pipe (3a),
It is also possible to adopt a structure in which a plurality of pipe sections on the outlet side are adjacent to the pipe sections on the inlet side. This makes it possible to equalize the temperature of the entire hydrogen storage alloy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hydrogen storage alloy container according to the present invention.

FIG. 2 is a cross-sectional view of a conventional hydrogen storage alloy container.

FIG. 3 is a diagram illustrating a model of a hydrogen gas utilization system using a conventional hydrogen storage alloy container.

FIG. 4 is a diagram showing a model of a hydrogen gas utilization system using the hydrogen storage alloy container of the present invention.

FIG. 5 is a graph showing a temporal change of a hydrogen storage amount using a heat transfer coefficient between an inlet pipe portion and an outlet pipe portion as a parameter.

FIG. 6 is a graph showing a distribution of stress acting on a cylindrical body using a heat transfer coefficient between an inlet pipe portion and an outlet pipe portion as a parameter.

[Explanation of symbols]

 (1) Cylindrical body (10) Hydrogen storage alloy container (11) Hydrogen storage alloy container (2) Hydrogen storage alloy (3) Heat medium pipe (31) Heat medium inlet (32) Heat medium outlet (3a) Inlet pipe ( 3b) Outlet piping (4) Heat transfer fin (5) Hydrogen gas absorption / release pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 17/12 C01B 3/00 F17C 11/00

Claims (5)

(57) [Claims] 1. A cylinder connected to a hydrogen gas absorption / desorption tube (5).
Inside (1), a storage chamber for the hydrogen storage alloy is formed, and a heat medium pipe (3) is provided, which is formed by directly connecting a plurality of pipe sections extending in the same direction in the alloy storage chamber to each other. A hydrogen storage alloy container having a heat medium inlet (31) and a heat medium outlet (32) at both ends of the heat medium pipe (3) protruding from the cylindrical body (1) to the outside; (3) Out of a plurality of pipe sections, the inlet pipe section (3a) through which the heat medium flows first and the outlet pipe section (3b) through which the heat medium flows last are adjacent to each other. Hydrogen storage alloy container. 2. The hydrogen storage alloy container according to claim 1, wherein a plurality of heat transfer fins (4) through which the plurality of pipes penetrate are arranged along the pipe axis direction in the alloy storage chamber. . 3. The hydrogen storage alloy container according to claim 1, wherein the alloy storage chamber is filled with a powdery hydrogen storage alloy. 4. The tubular body (1) is made of stainless steel, and a heat transfer coefficient between the inlet pipe section (3a) and the outlet pipe section (3b) of the heat medium pipe (3) is 20 W /. The hydrogen storage alloy container according to any one of claims 1 to 3, wherein an interval is set so as to be K or more. 5. A pair of cylinders (1) containing a hydrogen storage alloy.
(1) are connected to each other via a hydrogen gas absorption / desorption tube (5),
A storage chamber for the hydrogen storage alloy is formed inside each cylinder (1), and a plurality of pipes extending in the same direction in the alloy storage chamber are directly connected to each other by a heat medium pipe (3). ) Is installed, and both ends of the heat medium pipe (3) project from the cylinder (1) to the outside and have a heat medium inlet (31) and a heat medium outlet (32). The heat medium pipe (3) installed in the alloy storage chamber of each cylinder (1) has an inlet pipe part (3a) through which the heat medium flows first among the plurality of pipe parts, and a heat medium flows last. A hydrogen gas utilization system, wherein the outlet pipe section (3b) is adjacent to each other.