JPH0599074A - Hydrogen storage tank - Google Patents

Abstract

PURPOSE:To prevent a hydrogen storage tank filled with hydrogen occlusion alloys from being deformed or damaged by preventing hydrogen occlusion alloy powders from being concentrated in the lower part of the tank even if the tank is subjected to vibrations. CONSTITUTION:Mixed powders 8 which are a mixture of hydrogen occlusion alloy powders 6 and silicone resin powders 7 having elasticity are filled in a tank tube in a hydrogen storage tank. This constitution allows the silicone resin powders to absorb the expansion or contraction of the hydrogen occlusion alloy powders associated with hydrogen occlusion or emission to prevent the latter powders from being concentrated in the lower part 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 tank filled with hydrogen storage alloy powder for storing and releasing hydrogen.

[0002]

2. Description of the Related Art In recent years, as global warming has been taken up as an environmental problem, hydrogen fuel has been attracting attention as a clean alternative energy to petroleum. For example, hydrogen fuel should be used as a fuel for internal combustion engines for automobiles. Development is in progress. By the way, when hydrogen is used as a fuel, a hydrogen storage tank is an important position. One of such tanks is a hydrogen storage alloy (hereinafter, referred to as M
It is called H alloy. ) Is considered. Since the hydrogen storage tank using this MH alloy has excellent properties in terms of high hydrogen filling rate and safety, it is known to be particularly effective as a hydrogen storage tank for moving bodies such as automobiles. ..

FIG. 15 shows a tank tube in a conventional hydrogen storage tank. Tank tube 1
The double tube structure is composed of a cylindrical tube outer plate 2 and a cylindrical filter 3 concentrically provided at the center of the outer plate 2, and the inside of the filter 3 is a hydrogen flow path 4. .. The space defined by the tube outer plate 2 and the filter 3 is filled with MH alloy powder 5. In a conventional hydrogen storage tank, a plurality of such tank tubes 1 are arranged in a zigzag manner at intervals in a space surrounded by a rectangular parallelepiped tank outer plate. The space formed between 1 and the tank outer plate serves as a heat medium passage. In the hydrogen storage tank having such a configuration, the MH alloy powder 5 in the tank tube 1
The hydrogen stored therein is released by being heated by a heat medium, and the hydrogen released in this way passes through the filter 3 and is taken out from the hydrogen flow path 4 to the outside through the pipe connected to the end thereof. On the other hand, when hydrogen is stored in the MH alloy powder 5, hydrogen is fed from the high pressure cylinder through the hydrogen flow path 4 while the MH alloy powder 5 is being cooled.

Regarding the MH alloy material, for example, an agglomerate of MH alloy powder coated with a large number of fine particles of a metal such as aluminum is disclosed in, for example, JP-A-63-3109.
No. 36 is disclosed.

[0005]

However, in the case where the tank tube is simply filled with MH alloy powder as in the above-mentioned conventional hydrogen storage tank, the MH alloy powder expands and contracts due to the absorption and desorption of hydrogen. There was a problem that the tank tube was damaged or deformed. In particular,
When such a hydrogen storage tank is used by being mounted on a moving body such as an automobile, the MH alloy powder is atomized when hydrogen is released by placing the tank under vibration conditions.
The alloy powder moves and concentrates in the lower part of the tank tube as shown by the upper two-dot chain line in FIG. Then, when the MH alloy powder concentrated in the lower portion of the tank tube expands in volume when hydrogen is absorbed, pressure is applied to the lower portion of the tank tube as shown by an arrow in the figure, and the tank tube is indicated by a two-dot chain line on the lower side. There is a problem in that it deforms as shown and cracks occur depending on the case.

The one described in the above publication is intended to prevent MH alloy from being pulverized due to repeated storage and release of hydrogen, and is used by being mounted on a moving body in particular. It does not solve the above problems in the hydrogen storage tank.

The present invention has been made in view of the above problems, and in a hydrogen storage tank filled with MH alloy powder, the MH alloy powder is prevented from being unevenly distributed in the lower part of the tank, and the tank is deformed. ， The purpose is to prevent damage.

[0008]

A hydrogen storage tank according to the present invention is characterized by being filled with a mixed powder obtained by mixing a hydrogen storage alloy powder and a powder having elasticity.

[0009]

In the present invention, since the MH alloy powder is mixed with the powder having elasticity such as silicon and filled in the tank, the expansion and contraction of the MH alloy powder due to hydrogen absorption and release are elastic. Since the MH alloy powder is absorbed by the powder having the MH alloy, the MH alloy powder is uniformly held in the lower portion of the tank even when vibration is applied to the tank, and deformation and damage of the tank are prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings.

FIG. 1 is a sectional view of a tank tube in a hydrogen storage tank according to an embodiment of the present invention, FIG. 2 is a perspective view of the tank tube, and FIG. 3 is a partial front view of the hydrogen storage tank according to the embodiment. FIG. 4 is an enlarged view of part A of FIG.

In this embodiment, the tank tube 1
Is a double tube structure composed of a cylindrical tube outer plate 2 and a cylindrical filter 3 concentrically provided at the center of the tube outer plate 2, and a hydrogen flow path 4 is provided inside the filter 3. Are formed. Further, in the space defined by the tube outer plate 2 and the filter 3, the MH alloy powder (150 μm
6) and a silicon resin powder (100 μm or less) 7 are mixed, and a mixed powder 8 is filled. The mixed powder 8 is obtained by mixing the MH alloy powder 6 and the silicon resin powder 7 with an attritor, and when the mixed powder 8 is filled in the tank tube 1, the mixed powder 8 is about 1 kgf / cm ² . It is pressurized with pressure and the stopper at the end is closed in this pressurized state. Here, as the MH alloy, T
_{i 0 · 64 Zr 0 · 36} Mn 0 · 8 CrCu 0 · 2 and TiMn _{1 · 5} and F
It is preferable to use eTi or the like.

The tank tube 1 is a rectangular parallelepiped hydrogen storage tank 1 having a tank outer plate 9 as shown in FIG.
They are mounted in a zigzag pattern at intervals in a space surrounded by the above-mentioned tank outer plate 9. And each tank tube 1
The space formed between the tank tube 1 and the tank outer plate 9 serves as the heat medium flow passage 11. In the hydrogen storage tank 10 having such a configuration, the MH alloy powder 6 in the tank tube 1 is heated by the heat medium passing through the heat medium passage 11 to release the stored hydrogen, and the released hydrogen is filtered. It is taken out from the hydrogen flow path 4 through the pipe 3 through a pipe (not shown) connected to its end. on the other hand,
When hydrogen is stored in the MH alloy powder 6, hydrogen is fed from the high-pressure cylinder through the hydrogen flow path 4 and the filter 3 while the MH alloy powder 6 is being cooled.

According to this embodiment, the tank tube 1 is pressurized and filled with the mixed powder 8 obtained by mixing the MH alloy powder 6 and the silicon resin powder 7, and as shown in FIG.
Silicon resin powder 7 having elasticity between particles of alloy powder 6
Since the MH alloy powder 6 expands and contracts due to the absorption and desorption of hydrogen, the silicon resin powder 7 having elasticity is absorbed. Therefore, even when vibration is applied to the MH alloy powder 6,
The alloy powder 6 is uniformly held in the lower part of the tank tube 1 without being unevenly distributed, and therefore, the tank tube 1 can be prevented from being damaged or deformed. As a result of performing a vibration test for about 100 hours using the tank tube 1 of the present example in a state where hydrogen was not stored, it was confirmed that the mixed powder 8 inside was not unevenly distributed in the lower portion of the tank tube 1. It was Further, after this vibration test, hydrogen was introduced and occluded in the MH alloy powder 6, but the tank tube 1 was not damaged or deformed. As a comparative example, when the tank tube was filled with only the MH alloy powder at normal pressure and a vibration test was performed, it was found that voids were formed in the upper part of the outer periphery and the powder was unevenly distributed. Further, when hydrogen was subsequently introduced into the MH alloy powder to occlude it, it was observed that the lower portion of the tank tube was slightly deformed.

5 to 7 show various modifications of the tank tube of the above embodiment. Note that FIG. 5 is a cross-sectional view as seen from the side surface side, and FIGS. 6 and 7 are cross-sectional views as seen from the front surface side.

As shown in these figures, the filters 3a, 3b, 3 mounted in the tank tubes 1a, 1b, 1c are shown.
c may be bent at several points on the way to increase the passage length to increase the contact area with the mixed powder 8 (FIG. 5), or to form a groove portion whose cross-sectional shape extends radially from the central portion to the periphery. It may be formed to have a larger contact area with the mixed powder 8 (FIG. 6), or a large number may be attached to the tank tube 1c having a rectangular cross section to expand the contact area (FIG. 7). ), Etc., and can be implemented in various ways.

The problem of the concentration of MH alloy powder in the lower portion of the tank tube, which occurs when the hydrogen storage tank is mounted on a moving body such as an automobile, can be solved by the following means. That is, FIG. 8 is a cross-sectional view of a tank tube according to another embodiment of the present invention that addresses the above problems, and FIG. 9 is a perspective view of the tank tube.

In the tank tube 12 of this embodiment, the tube outer plate 13 is formed of a material (for example, Al-5082) having excellent heat conduction characteristics and capable of withstanding internal hydrogen pressure, and further, the filter 14 is provided with the tank tube 12.
The inside is shaped so as to be partitioned into four fan-shaped MH alloy powder filling regions 15 and a cross-shaped hydrogen flow path 16, and the filter 14 has the ability to separate MH alloy powder and hydrogen and has excellent thermal conductivity. Material (for example, sintered SUS-304)
It was formed in.

According to this embodiment, the filter 14 serves as a partition plate to prevent the atomized MH alloy powder from moving and concentrating in the lower portion of the tank tube 12. In addition, with such a configuration, the filter 14 causes the tank tube 1
Since it functions as a reinforcing material of No. 2, it is also advantageous for the internal pressure of hydrogen, and since the filter 14 also functions as a heat conduction promoting material between the MH alloy powder and the tube outer plate 13, Exchange of heat with the heat medium is promoted, and thereby the hydrogen storage / release reaction rate of the MH alloy powder is increased. Further, according to the above configuration, the hydrogen flow path 1
Since the surface area of 6 becomes large, there is an effect that hydrogen can be easily taken in and out.

FIG. 10 shows a modification of this embodiment. In the tank tube 17 of this example, the filter 18
Is shaped so as to partition the inside of the tank tube 17 into five fan-shaped MH alloy powder filling regions 19, and the filter 18 is made of a material excellent in hydrogen permeation characteristics (for example, SU.
S-304 fiber felt), and the filter 18 itself serves as a hydrogen flow path.

The filter 18 having such a structure does not serve as a reinforcing material in terms of strength unlike the filter 14 shown in FIGS. 8 and 9, but has a partition plate effect and a high hydrogen storage / release reaction rate. The same effects as those of the above-described embodiment are obtained with respect to the point and the fact that hydrogen can be easily taken in and out. As a result of the test, it was confirmed that the tank tube of this example was superior to that of the conventional example in terms of the presence or absence of deformation and cracking and in the hydrogen storage / release rate.

By the way, in the hydrogen engine vehicle equipped with the hydrogen storage tank as described above, the cooling water of the engine is used as a heat medium to release hydrogen from the MH alloy powder and supply it to the engine. However, in such a structure in which the cooling water is simply circulated, there is a problem that the amount of released hydrogen becomes insufficient at the time of starting or sudden acceleration, which requires a larger hydrogen flow rate than during steady running.

FIG. 11 shows an example of a control system that addresses such a problem. In this example, the engine 20
From the hydrogen storage tank (MH tank) 21 to the heat medium passage 22 in the middle, for example, a pump 2 with an emission amount of 0 to 40 L / min
3 is provided, an opening sensor 25 is provided in the throttle portion that interlocks with the accelerator 24 so that the sensor 25 detects the depression amount of the accelerator 24.
The discharge amount of the pump 23 is increased according to the depression amount of the heat medium to increase the flow rate of the heat medium, thereby increasing the flow rate of hydrogen supplied to the engine 20 through the hydrogen flow path 26.

According to such a system, for example, the heating medium temperature is 80 ° C. and the discharge amount of the pump 23 is 15 L / min.
During normal driving, approximately 400 L / min of hydrogen is consumed by the engine 2.
0 is supplied, but at the time of acceleration when the amount of depression of the accelerator 24 is maximized, the discharge amount of the pump 23 becomes 40 L / min, and about 1700 L / min of hydrogen is supplied to the engine 20, so during acceleration, etc. Engine power can be improved.

FIG. 12 shows a modification of the control system. In this example, in addition to engine cooling water, exhaust gas is circulated in the hydrogen storage tank 27 by a supply device 28, and the supply device 28 is controlled by a control unit 30 in response to a signal from an accelerator opening detection sensor 29. Configured to do so. Even with such a system, a large amount of hydrogen can be supplied to the engine 31 in a short time at the time of starting or sudden acceleration.
Can be supplied to.

FIG. 13 shows still another modification. In the case of this example, a heater heated by the battery 32 is built in the hydrogen storage tank 27 ', and the battery 32 is controlled by the control unit 30' according to a signal from the accelerator opening detection sensor 29. It is configured as follows.
With such a system, as in the above case, a large amount of hydrogen can be supplied to the engine 31 in a short time at the time of starting or sudden acceleration.

FIG. 14 shows another modification of the control system. In this example, the piping system from the hydrogen storage tank 33 to the engine is connected to the main pipeline 34 and the bypass pipeline 3.
5, and each of these pipelines 34, 35 is provided with a first valve 36 and a second valve 37, and at the upstream side of the second valve 37 in the bypass pipeline 35 for storing compressed hydrogen. The surge tank 38 and the small compressor 39 for storing the compressed hydrogen are respectively arranged in the surge tank 38, and the control unit 40 for controlling the opening and closing of the valves 36 and 37 according to the accelerator opening is provided. ing.

In this system, at the time of normal traveling, the first valve 36 is opened and the second valve 37 is closed to supply hydrogen from the main pipe 34 to the engine 41 and the small compressor 39. Upon operation, a spare hydrogen gas is stored in the surge tank 38 via the bypass line 35. When the compressed hydrogen in the surge tank 38 reaches a predetermined pressure, the operation of the small compressor 39 is stopped to stand by in preparation for the large flow rate supply. On the other hand, when hydrogen is supplied from the engine 41 at a predetermined flow rate or more, such as when the vehicle starts or suddenly accelerates, the first valve 36 is closed and the second valve 37 is closed by a signal from the control unit 40 according to the accelerator opening. Is opened to supply the compressed hydrogen stored in the surge tank 38 to the engine. Even with such a system, similarly to the above, a large amount of hydrogen can be supplied to the engine 41 in a short time at the time of starting or sudden acceleration, and the operation can be continued without impairing the power performance of the engine. it can.

[0029]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, when the expansion and contraction of MH alloy powder due to hydrogen absorption and desorption is absorbed by the elastic powder, and the hydrogen storage tank is vibrated. However, the MH alloy powder is uniformly held in the lower portion of the tank without being unevenly distributed, and the deformation and damage of the tank can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a tank tube in a hydrogen storage tank according to an embodiment of the present invention.

FIG. 2 is a perspective view of a tank tube in the hydrogen storage tank according to the embodiment.

FIG. 3 is a partial front view of the hydrogen storage tank according to the embodiment.

FIG. 4 is an enlarged view of part A of FIG.

FIG. 5 is a sectional view showing a first modification of the tank tube of the same embodiment.

FIG. 6 is a sectional view showing a second modification of the tank tube of the same embodiment.

FIG. 7 is a sectional view showing a third modification of the tank tube of the same embodiment.

FIG. 8 is a sectional view of a tank tube in a hydrogen storage tank according to another embodiment of the present invention.

FIG. 9 is a perspective view of the tank tube of the embodiment.

FIG. 10 is a cross-sectional view showing a modified example of the tank tube of the same embodiment.

FIG. 11 is a diagram showing an example of a control system for a hydrogen engine vehicle equipped with the hydrogen storage tank of the present invention.

FIG. 12 is a diagram showing a first modification of the control system.

FIG. 13 is a diagram showing a second modification of the control system.

FIG. 14 is a diagram showing a third modification of the control system.

FIG. 15 is a diagram showing a fourth modification of the control system.

[Explanation of symbols]

 1 Tank Tube 6 Hydrogen Storage (MH) Alloy Powder 7 Silicon Resin Powder 8 Mixed Powder 10 Hydrogen Storage Tank

Front Page Continuation (72) Inventor Tsutomu Shimizu No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Toru Ogasawara No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Corporation

Claims (1)

[Claims] 1. A hydrogen storage tank filled with a mixed powder obtained by mixing a hydrogen storage alloy powder and a powder having elasticity.