JPH0783396A - Hydrogen storage alloy tank for hydrogen storage - Google Patents

Abstract

PURPOSE:To provide a hydrogen storage alloy tank for hydrogen storage provided with a hydrogen injection nozzle hard to generate maldistribution of a hydrogen storage alloy in the tank, in the case of hydrogen injection. CONSTITUTION:In a hydrogen storage alloy tank 1 for or hydrogen storage in which a hydrogen injection nozzle, having at least one jet hole 3 for jetting hydrogen gas, is provided in one end in a lengthwise direction of the tank, at least one jetting directional vector of hydrogen, jetted from the hydrogen injection nozzle, has a directional component orthogonal to the lengthwise direction of the tank.

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 tank for storing hydrogen having a hydrogen injection nozzle, and more particularly to an improvement of the hydrogen injection nozzle.

[0002]

2. Description of the Related Art In recent years, the demand for clean energy has further increased with the growing interest in preserving the global environment. Against this background, the importance of hydrogen as clean energy is increasing more than ever before.
By the way, since hydrogen is usually a gas and is an extremely active substance, how to properly and individually store hydrogen having such a property is an important issue in advanced utilization of hydrogen energy. For example, as a power source for space development rockets and electric vehicles, there is a tendency to utilize hydrogen fuel cells, which have high energy conversion efficiency and little influence on environmental pollution. In this case, first, how to supply hydrogen as a cell fuel The question is whether to do it. In addition, in order to use the solar energy, which is an inexhaustible resource, so-called solar power generation is performed in the desert, etc., the power is once converted to hydrogen through electrolysis of water, and the energy is stored in the form of hydrogen. When it is considered to be transported and used, the first problem is how to store and store hydrogen as in the above case. That is,
How to store hydrogen appropriately and conveniently is the key to the advanced utilization of hydrogen energy.

Recently, however, a hydrogen storage alloy capable of reversibly storing and releasing hydrogen has attracted attention, and a method of storing hydrogen by storing hydrogen in this hydrogen storage alloy is used as a hydrogen storage method. It is becoming. According to this method, individual storage of hydrogen (referred to as storage in arbitrary units) is facilitated, and it is also easy to take out hydrogen. Therefore, compared with the conventional high-pressure liquefaction storage method, hydrogen and hydrogen utilization The utilization range of the device can be greatly expanded.

[0004]

SUMMARY OF THE INVENTION The inventors of the present invention have
Based on the above situation, when reviewing the conventional hydrogen storage alloy tank for storing hydrogen by causing the hydrogen storage alloy to store hydrogen, the following problems were found. That is, in the hydrogen injection nozzle used in the conventional hydrogen storage alloy tank for storing hydrogen, since the direction of hydrogen injection is parallel to the nozzle axis direction, when injecting hydrogen, the injected hydrogen remains in the tank. It hits the hydrogen storage alloy. Therefore, as shown in FIG. 7, the hydrogen-absorbing alloy particles are pushed toward the back of the tank. In this case, however, the finer particles are pushed further toward the back, so that the hydrogen-absorbing alloy distribution in the tank is It is unevenly distributed in terms of location and granularity. Here, the hydrogen storage alloy expands exothermically when it absorbs hydrogen, but in the part where the hydrogen storage alloy is unevenly distributed and has a high density (in the tank), the temperature rises abnormally due to the effect of this exothermic expansion, and Due to the expansion, the internal pressure is abnormally increased and the tank wall is strongly pressed. The heat-expanding action applied locally in this manner causes fatigue (for example, metal fatigue) of the tank wall surface. In other words, due to repeated storage and release of hydrogen, the tank wall gradually deteriorates due to fatigue, which causes unexpected situations such as distortion and deformation of the tank, and further rupture.

Based on the above recognition, the present invention provides a hydrogen storage alloy tank for hydrogen storage, which is equipped with a hydrogen injection nozzle that is less likely to cause uneven distribution of the hydrogen storage alloy during hydrogen injection. To aim.

[0006]

To achieve the above object, the present invention according to claim 1 provides a hydrogen injection nozzle having at least one ejection hole for ejecting hydrogen gas, wherein one end in the longitudinal direction of the tank. In the hydrogen storage alloy tank for hydrogen storage provided in, at least one of ejection direction vectors of hydrogen ejected from the hydrogen injection nozzle has a directional component orthogonal to the longitudinal direction of the tank. To do.

According to a second aspect of the present invention, in the hydrogen storage alloy tank for storing hydrogen according to the first aspect, the hydrogen injection nozzle adjusts the hydrogen injection pipe and the wind direction of hydrogen ejected from the injection pipe. And a guide plate that operates. Further, according to the present invention of claim 3, in the hydrogen storage alloy tank for hydrogen storage according to claim 1, the hydrogen injection nozzle includes a cylindrical hydrogen ejection member having a plurality of hydrogen ejection holes on a peripheral side surface thereof. It is characterized by

According to a fourth aspect of the present invention, in the hydrogen storage alloy tank for hydrogen storage according to the third aspect, a plurality of hydrogen ejection holes provided on the peripheral side surface are provided in the periphery of the hydrogen storage alloy tank for hydrogen storage. It is characterized by being arranged in the direction. Furthermore, the present invention according to claim 5 is the hydrogen storage alloy tank for hydrogen storage according to claim 3, wherein a plurality of hydrogen ejection holes provided on the peripheral side surface are arranged in a longitudinal direction of the hydrogen storage alloy tank for hydrogen storage. It is characterized by being

According to the sixth aspect of the present invention, the plurality of hydrogen ejection holes arranged in the longitudinal direction are arranged so that the ejection speed or ejection amount from each ejection hole is the same, and the diameters of the holes are increased toward the tip side. Is formed to be large.

[0010]

According to the above structure, the hydrogen ejected from the hydrogen ejection nozzle provided at one end of the tank in the longitudinal direction is
Since it has a jetting direction component other than the longitudinal direction, the wind pressure that hits the hydrogen storage alloy powder is relaxed. Therefore, it is possible to alleviate the phenomenon that the hydrogen storage alloy powder scatters in the tank due to the hydrogen ejection pressure and is unevenly distributed. Therefore, hydrogen can be efficiently injected into the tank.

[0011]

Embodiments of the present invention will be described with reference to the drawings. [First Embodiment] A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of a hydrogen storage alloy tank for hydrogen storage equipped with a hydrogen injection nozzle in which eight hydrogen gas ejection holes are arranged along the longitudinal direction of a cylindrical hydrogen ejection member. In FIG. 1, 1 is a hydrogen storage alloy tank main body for hydrogen storage, 2b is a hollow rod-shaped hydrogen ejection member, 3 is a hydrogen gas ejection hole, 4 is a filter, 5 is a hydrogen gas supply pipe, and the direction of the arrow is hydrogen gas. The spouting direction of is shown. Here, the hydrogen storage alloy tank main body 1 for storing hydrogen has a length of 159 mm, a diameter of 38 mm, and a wall thickness of 2 mm, which has a hydrogen injection nozzle attachment port at one longitudinal end and the other end is closed. It is a cylindrical tank. Further, the hydrogen injection nozzle has a filter for removing dust and the like from hydrogen gas on the rear end side, and a diameter of 6.
A hollow rod-shaped hydrogen ejection member 2b having a length of 35 mm and a length of about 150 mm is attached. The hydrogen ejection member 2 is provided with eight holes substantially evenly along the longitudinal direction, and dust and the like are removed from the hydrogen gas inside each hole and the inflow of the hydrogen storage alloy is prevented. In order to do so, filters (2 μm) each having a diameter of 2.5 mm are attached. The material of the tank body and the hydrogen injection nozzle having such a shape is aluminum alloy (A5052). [Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is an example in which four hydrogen gas ejection holes are arranged in two rows along the longitudinal direction of the hydrogen ejection member. However, the method of arranging the hydrogen gas ejection holes may be appropriately determined, and for example, may be arranged in four rows and two stages, or may be arranged in a spiral shape. Further, the hole diameter may be increased as it goes in the longitudinal direction so that the hydrogen gas ejection amount or ejection velocity is the same for each ejection hole. By doing so, it is possible to effectively prevent the uneven distribution phenomenon of the hydrogen storage alloy particles caused by the ejection of hydrogen gas. The reason why the pore diameter is increased toward the tip is that the hydrogen pressure decreases toward the downstream side. [Third Embodiment] A third embodiment of the present invention will be described with reference to FIGS. In FIG. 2, 2b is a flat type hydrogen gas ejection member in which hydrogen gas ejection holes are arranged along the circumferential direction. An enlarged perspective view of the hydrogen gas ejection member 2b is shown in FIG. 4, and is a cylindrical body having a diameter of 9.5 mm and a thickness of 8 mm, and eight hydrogen gas ejection holes having a diameter of 2.5 mm are formed on the circumferential surface thereof. It is arranged. The reference numerals are the same as those in the first embodiment, and the materials for the hydrogen gas ejection member and the like are also the same as those in the first embodiment.

The hydrogen spouting member shown in the third embodiment is different from that of the first embodiment in that hydrogen is spouted in the circumferential direction, that is, in the direction orthogonal to the longitudinal direction.
Therefore, when the shape of the hydrogen storage alloy tank has a large diameter and is short in the longitudinal direction, the function and effect of the present invention are more effectively exhibited. [Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIGS. Example 4 is a system in which a guide plate is provided in front of the hydrogen gas injection pipe, and the direction of hydrogen gas ejected from the injection pipe is changed by the guide plate to form a directional component orthogonal to the tank longitudinal direction. Is an example of.

In FIG. 4, (a) shows that a disc-shaped baffle plate (guide plate) is arranged in front of the hydrogen injection pipe, and the hydrogen gas ejected from the injection pipe hits the baffle plate and is orthogonal to the longitudinal direction. It is a hydrogen ejection member configured to bend in the direction of. Further, (b) is a hydrogen ejection member in which the apex of the conical body is arranged on the injection pipe side and the side surface of the cone acts as a guide plate to guide the hydrogen gas ejected from the injection pipe in a predetermined direction. Further, (c) is a hydrogen ejection member configured such that the side surface of the conical body is formed in a curved shape (trumpet shape) so that the bending in the direction orthogonal to the longitudinal direction is larger than in the case of (b).

Although the cylindrical hydrogen jetting member is used in the first to third embodiments, it may have a conical tubular shape, a rectangular tubular shape, a triangular tubular shape, a quadrangular tubular shape, or the like. In addition, the shape of the guide plate in the fourth embodiment is not particularly limited, and a shape suitable for a desired ejection direction may be set appropriately. Further, in each of the drawings showing the above-mentioned embodiment, the hydrogen jetting members are drawn in the exposed state, but these hydrogen jetting members can be covered with a cover as long as they do not interfere with the hydrogen jetting. [Comparative Example 1] A conventional hydrogen storage alloy tank for hydrogen storage shown in Fig. 7 having a hydrogen injection nozzle having only a jet component in the longitudinal direction of the tank was produced. In the hydrogen storage alloy tank for hydrogen storage of Comparative Example 1, the material and size of the tank body and the material of the hydrogen injection nozzle were the same as those in Examples 1 to 4, and the shape and size of the hydrogen injection nozzle were the same. It is the same as the hydrogen injection tube of Example 4.

[Experiment] Example 1, Example 2, Example 3,
The tank of Comparative Example 1 was filled with 570 g of a hydrogen storage alloy powder of misch metal type (Lm, Y, Ni) having a bulk density of 4.8 g / ml. In this case, the filling rate of the hydrogen storage alloy powder in the tank inner volume is 50%.

Next, in any of the tanks of the examples, the flow velocity at the main pipe portion (hydrogen supply source side) of the hydrogen injection nozzle was 7 m.
The hydrogen gas pressure is applied so that the pressure becomes / sec, and 6
0 liter of hydrogen was injected and the uneven distribution of alloy powder in the tank was observed. (Results) The hydrogen gas injection time under the above conditions was about 15 minutes, and the situation in each example tank in this case was as follows.

In the tank of Comparative Example 1, as shown in FIG. 7, the alloy powder is deep in the tank (downstream) due to the force of gas ejection.
It was pushed to me. Further, there was finer alloy powder in the back and coarser alloy powder in the front. Furthermore, it was visually observed that the inner part of the tank expanded as hydrogen was absorbed. This expansion results in a high density filling of the hydrogen storage alloy in the inner part of the tank, so that the expansion pressure of the hydrogen storage alloy due to the storage of hydrogen gathers locally and becomes strong. It is considered that this is because the wall surface is strongly pressed.

On the other hand, in Examples 1 to 3, uneven distribution of the alloy powder was small, and expansion of the tank was not observed. In Examples 1 to 3, the ejection speed of hydrogen gas ejected from each ejection hole of the hydrogen injection nozzle was 1 m / se.
It was less than or equal to c. On the other hand, in Comparative Example 1, in order to reduce uneven distribution of the alloy powder, the hydrogen injection rate was reduced. Even if the hydrogen injection time was doubled or longer, Examples 1 to 3 were performed.
The uneven distribution of the hydrogen storage alloy powder was larger than that of the above.

[0019]

As described above, according to the present invention, when hydrogen is injected into the hydrogen storage alloy tank, the alloy powder in the tank is pushed into the depth of the tank due to the wind pressure of the injected hydrogen and is scattered. Uneven distribution can be suppressed. For this reason, the hydrogen storage alloy tank for hydrogen storage of the present invention, as in the case of the conventional hydrogen storage alloy tank for hydrogen storage, without uneven control of the hydrogen injection amount per unit time, uneven distribution of the alloy powder Hard to happen. Therefore, it is possible to shorten the hydrogen injection work and prevent the phenomenon that the hydrogen storage expansion of the hydrogen storage alloy causes metal fatigue or the like in the tank.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a hydrogen storage alloy tank for storing hydrogen according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a hydrogen storage alloy tank for hydrogen storage according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a hydrogen storage alloy tank for storing hydrogen according to a third embodiment of the present invention.

FIG. 4 is an enlarged perspective view showing a hydrogen ejection nozzle portion of a hydrogen storage alloy tank for hydrogen storage according to a third embodiment of the present invention.

FIG. 5 is an enlarged perspective view showing a hydrogen ejection nozzle portion of a hydrogen storage alloy tank for hydrogen storage according to a fourth embodiment of the present invention.

FIG. 6 is an enlarged perspective view showing a hydrogen ejection nozzle portion of a hydrogen storage alloy tank for hydrogen storage according to another embodiment of the present invention.

FIG. 7 is a schematic sectional view showing a hydrogen storage alloy tank for storing hydrogen according to a conventional example.

[Explanation of symbols]

 1 Hydrogen storage alloy tank main body for hydrogen storage 2 Hydrogen ejection member 3 Ejection hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Tsutsumi 2-18 Keihan Hondori, Moriguchi-shi Sanyo Electric Co., Ltd.

Claims (6)

[Claims] 1. A hydrogen injection nozzle having at least one injection hole for ejecting hydrogen gas is ejected from the hydrogen injection nozzle in a hydrogen storage alloy tank for hydrogen storage, which is provided at one longitudinal end of the tank. A hydrogen storage alloy tank for hydrogen storage, wherein at least one of the jetting direction vectors of hydrogen has a direction component orthogonal to the longitudinal direction of the tank. 2. The hydrogen storage hydrogen according to claim 1, wherein the hydrogen injection nozzle comprises a hydrogen injection pipe and a guide plate for adjusting a wind direction of hydrogen ejected from the hydrogen injection pipe. Storage alloy tank. 3. The hydrogen storage alloy tank for storing hydrogen according to claim 1, wherein the hydrogen injection nozzle includes a cylindrical hydrogen ejection member having a plurality of hydrogen ejection holes on a peripheral surface thereof. 4. The hydrogen storage hydrogen storage hydrogen storage tank according to claim 3, wherein the plurality of hydrogen ejection holes provided on the peripheral side surface are arranged in the circumferential direction of the hydrogen storage hydrogen storage alloy tank. Alloy tank. 5. The hydrogen storage hydrogen storage tank according to claim 3, wherein the plurality of hydrogen ejection holes provided on the peripheral side surface are arranged in the longitudinal direction of the hydrogen storage alloy tank for hydrogen storage storage. Alloy tank. 6. The plurality of hydrogen ejection holes arrayed in the longitudinal direction are formed so that the ejection holes from the ejection holes have the same ejection velocity or ejection amount and have a larger diameter toward the tip end. The hydrogen storage alloy tank for storing hydrogen according to claim 5.