JP2002327898A - Hydrogen storage and supply equipment - Google Patents

Abstract

(57) [Problem] To provide a hydrogen storage / supply device having a high-performance hydrogen storage tank that can make the heat exchange efficiency on the upstream side and the downstream side uniform with respect to the flow of a heat transfer medium. SOLUTION: A hydrogen storage tank 1 that stores hydrogen by cooling a hydrogen storage alloy 1d housed in a tank and releases hydrogen by heating, and the hydrogen storage tank 1
Hydrogen provided on at least one of the outside and inside of the heat transfer medium and having a heat transfer medium flow path (external heat transfer medium passage 2) through which a heat transfer medium for transferring heat to and from the hydrogen storage alloy 1d flows. In the storage / supply device, the hydrogen storage tank 1
Heat exchange fins 1b are provided so that the heat transfer area between the hydrogen storage alloy and the heat transfer medium is larger on the downstream side in the flow direction of the heat transfer medium than on the upstream side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen storage / supply device utilizing the storage / release characteristics of a hydrogen storage alloy for supplying hydrogen to a fuel cell or the like. The present invention relates to a structure of a heat exchanger for heating and cooling a hydrogen storage alloy.

[0002]

2. Description of the Related Art A hydrogen storage alloy (hereinafter referred to as a hydrogen storage tank) is used.
It is well known from the material properties that when hydrogen is stored or released in a MH tank, an exothermic reaction occurs when hydrogen is stored, and an endothermic reaction occurs when hydrogen is released. Alternatively, the metal hydride decomposition reaction is suppressed. Conventionally, in order to improve the heat balance of the heat of reaction, JP-A-11-60201, JP-A-2000-170998,
MH as disclosed in Japanese Patent Application No. 0-120996 and the like.
It is well known to provide a passage through which a heat transfer medium flows in a tank to improve the reaction speed. Further, a method of improving the thermal conductivity by mixing a hydrogen storage alloy and a good thermal conductive binder (metal binder) is disclosed in JP-A-11-31140.
No. 0 discloses this. JP 2000-17099
No. 8 discloses a method of increasing the contact area with a fin or a corrugated plate in order to improve the thermal conductivity between the heat transfer medium (or the inner wall of the hydrogen storage container) and the hydrogen storage alloy. Further, in order to improve the supply rate of hydrogen to the hydrogen storage alloy inside the MH tank, Japanese Patent Application Laid-Open
It is well known in 000-120996 and the like to secure a hydrogen flow path inside a tank.

[0003]

However, in the case of an MH tank using a hydrogen storage alloy, the metal hydride generation heat is removed when hydrogen is absorbed, and the heat required for decomposition of the metal hydride is released when hydrogen is released. Need to be added to
In order to utilize the performance of the hydrogen storage alloy, it is desirable to cool (heat storage) or heat (release hydrogen) the hydrogen storage alloy in the MH tank as uniformly as possible. In order to facilitate the transfer of heat, it is effective to increase the surface area (heat transfer area) of the MH tank.
A conventional plate-shaped air-cooled fin 100 as shown in FIG. 5A or an annular air-cooled fin 200 as shown in FIG.
In this case, the number of man-hours for manufacturing the MH tank increases, so that the manufacturing cost is high. Further, it is difficult to reduce the thickness of the fins, so it is difficult to reduce the weight of the MH tank.

In addition, when a fin having a conventional structure is attached to a simple air-cooled MH tank and hydrogen is stored in a hydrogen storage alloy while being cooled by a refrigerant, the heat dissipation characteristic of the MH tank is as follows.
As shown in FIG. 6, since the heat exchange efficiency is high on the upstream side of the refrigerant flow (surface heat dissipation is high), and the heat exchange efficiency is low on the downstream side (surface heat dissipation is low), the entire MH tank is made uniform. It was difficult to use. When this occurs, for example, only a certain portion is preferentially cooled at the time of occlusion, and the other portions cannot sufficiently remove the heat of reaction due to the metal hydride generation reaction, thereby hindering hydrogen occlusion. Therefore, the hydrogen storage alloy cannot be used effectively. Further, the hydrogen storage alloy is pulverized by repeatedly occluding and releasing hydrogen, and when heat exchange efficiency is uneven, pulverization proceeds locally. As the pulverization progresses, (1) the pulverized hydrogen storage alloy flows out of the MH tank and, for example, closes pipes and valves provided in the hydrogen flow path and adversely affects other systems. The surface area per unit volume of the converted hydrogen storage alloy is increased, the hydrogen storage alloy easily reacts with impurities contained in a small amount in hydrogen gas, and the hydrogen storage alloy itself has a problem of deteriorating the hydrogen storage / release capability.

The present invention has been made to solve the above-mentioned problems, and has a high-performance hydrogen storage tank capable of making the heat exchange efficiency of the upstream and downstream sides uniform with respect to the flow of the heat transfer medium. It is an object to provide a hydrogen storage / supply device.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an MH tank using a hydrogen storage alloy, in which the structure of heat exchange fins is changed to an upstream side (FIG. 1) so that heat exchange with a heat transfer medium can be performed uniformly.
By changing the performance (configuration) of the heat exchanger for each flow direction of the heat transfer medium by making the fin pitch of the refrigerant inlet side coarse and the fin pitch of the downstream side dense, , MH) due to a change in heat exchange performance due to a change in the temperature of the heat transfer medium accompanying cooling or heating, making it possible to make the heat exchange efficiency of the MH tank uniform. For example, the structure of the heat exchange fin can be easily realized by using a fin bent in a bellows shape as shown in FIG.

When a refrigerant passage is provided in the MH tank, the density of the heat exchange fins is reduced on the upstream side (reducing the surface area involved in heat transfer), and the density of the heat exchange fins is increased on the downstream side (heat transfer fins). The same effect is exhibited by increasing the surface area involved in

It is also an important improvement that the heat exchange fins of the MH tank used in the present invention can easily realize an arbitrary fin pitch and fin height by using a bent thin plate.

According to a first aspect of the present invention, there is provided a hydrogen storage / supply device that cools a hydrogen storage alloy stored in a tank to store hydrogen and heats the hydrogen storage alloy to release hydrogen. A hydrogen storage / supply device provided on at least one of the outside and the inside of the storage tank and comprising a passage for a heat transfer medium flowing through a heat transfer medium for transferring heat with the hydrogen storage alloy; The storage tank is provided with heat exchange fins such that the heat transfer area is larger on the downstream side in the flow direction of the heat transfer medium than on the upstream side.

According to the first aspect of the present invention, a hydrogen storage tank that stores hydrogen by cooling a hydrogen storage alloy housed in the tank and releases hydrogen by heating, and an outside or inside of the hydrogen storage tank A hydrogen storage / supply device provided on at least one of the hydrogen storage alloys and a heat transfer medium passage through which a heat transfer medium for transferring heat is provided. By providing heat exchange fins so that the heat transfer area between the hydrogen storage alloy and the heat transfer medium is larger on the downstream side in the flow direction of the heat medium than on the upstream side, a complicated heat transfer medium passage is formed. In addition, since the entire hydrogen storage alloy can be used uniformly, the heat exchange efficiency is improved. Further, the hydrogen storage alloy is pulverized by repeating the storage and release of hydrogen, but local pulverization is suppressed by configuring as described above.

According to a second aspect of the present invention, there is provided a hydrogen storage device comprising a plurality of heat exchange layers provided with the heat exchange fins in a traveling direction of the heat transfer medium, wherein the heat transfer medium flows from an upstream side to a downstream side. 2. The hydrogen storage / supply device according to claim 1, wherein heat exchange fins of each heat exchange layer are arranged so as to generate turbulence.

According to the second aspect of the present invention, a plurality of heat exchange layers having heat exchange fins are provided in the traveling direction of the heat transfer medium, and turbulence occurs when the heat transfer medium flows from the upstream side to the downstream side. By arranging the heat exchange fins of each heat exchange layer such that the heat transfer medium is sufficiently stirred when the heat transfer medium passes through the gap between the heat exchange fins, the heat exchange efficiency is further improved.

According to a third aspect of the present invention, in the hydrogen storage device, a large number of the heat exchange fins are provided on a downstream side of an upstream side in a flow direction of the heat transfer medium. A hydrogen storage device according to item 1.

According to the third aspect of the present invention, since a number of heat exchange fins are provided on the downstream side of the upstream side in the flow direction of the heat transfer medium, the heat transfer area on the downstream side can be increased. Side heat exchange efficiency can be increased. As a result, the heat transfer performance can be improved as compared with the case where heat exchange fins of the same shape are attached at a constant fin pitch.

According to a fourth aspect of the present invention, in the hydrogen storage device, the heat exchange fins, which are higher than the heat exchange fins on the upstream side, are provided downstream of the upstream side in the flow direction of the heat transfer medium. The hydrogen storage device according to claim 1, wherein the hydrogen storage device is provided.

According to the fourth aspect of the invention, the surface area is increased by providing the heat exchange fins, which are higher in height than the heat exchange fins on the upstream side, on the downstream side of the upstream side in the flow direction of the heat transfer medium. Is possible, so that the heat transfer performance can be improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention of a hydrogen storage / supply device according to the present invention will be described with reference to the drawings. FIG. 1 shows that when the MH tank is externally cooled or heated,
It is a figure which shows the whole structure of the hydrogen storage / supply apparatus of 1st Embodiment which has the improved modulation | alteration structure fin which can cool or heat a hydrogen storage alloy uniformly in MH tank.
In the embodiment of the present invention, the amount of heat that is exchanged between the heating and the cooling is substantially the same, so that the operation and effect will be described in detail only during the cooling (when storing hydrogen). As shown in FIG. 1, the hydrogen storage / supply device according to the first embodiment includes a hydrogen storage alloy 1 accommodated in a tank having at least a hydrogen inlet 1a.
An MH tank 1 that absorbs hydrogen by cooling d and releases hydrogen by heating, and an outer surface of the MH tank 1 has a heat transfer area on the downstream side in the flow direction of the heat transfer medium that is larger than the upstream side. Heat exchange fin 1b provided to be large
And an external heat transfer medium passage 2 that is provided so as to surround the outer surface of the MH tank 1 and passes a heat transfer medium for transferring heat to and from the hydrogen storage alloy 1d. Unit is configured.

The MH tank 1 has a hydrogen storage alloy 1d inside.
Is a cylindrical pressure vessel, and a hydrogen inlet 1a is provided upstream of the flow of the heat transfer medium. The hydrogen inlet 1a is a pipe for introducing a hydrogen gas into the hydrogen storage alloy 1d from a high-pressure hydrogen source (not shown) via a filling unit. The hydrogen outlet of the MH tank 1 can also serve as the hydrogen inlet 1a, or can be provided as a separate pipe.

The heat exchange fins 1b are attached along the circumferential direction of the outer surface of the MH tank 1, and are provided so that the downstream side in the flow direction of the heat transfer medium has a larger heat transfer area than the upstream side. These are projections. The heat exchange layer 1c provided with the plurality of heat exchange fins 1b, as can be seen from FIG.
In each block of the heat exchange layer 1c, the fin density is coarse on the upstream side and dense on the downstream side with respect to the flow direction of the heat transfer medium. As a method of increasing the fin density, the heat exchange fins 1b are provided for each heat exchange layer 1c from upstream to downstream in the flow direction of the refrigerant.
There is a method of increasing the number of fins or increasing the height of the heat exchange fins 1b. These may be performed together.

A heat exchange layer 1 is provided on the outer peripheral surface of the MH tank 1.
c is provided in a plurality of blocks along the flow direction of the heat transfer medium, and the heat exchange fins 1b are provided so as not to overlap with each block of the heat exchange layer 1c. The heat exchange efficiency is further improved because the flow is suitably agitated and the turbulent state is generated when passing through.

In the present embodiment, the heat exchange fin 1b is
A wavy plate formed by bending a thin plate as shown in FIG. 1 into a bellows shape is welded or brazed along the outer periphery of the MH tank 1 to be erected. In the case of brazing, the MH tank 1 and the heat exchange fins 1b are connected to a non-corrosive flux such as KAlF ₄ , K ₃ AlF ₆ , K2AlF _5.
It is preferable to join with a flux containing a single substance of H ₂ O or a mixture thereof. in this case,
It is preferable to apply a non-corrosive flux to at least one of the MH tank 1 and the heat exchange fins 1b. In this embodiment, the material is an aluminum alloy. In this case, as the non-corrosive flux, for example, Si and a flux (KAlF ₄ + K ₃ Al
It is preferred that the mixture of F ₆ ) is previously applied to the metal surface to be joined. By bending and using the thin plate in a bellows-like manner, an arbitrary fin pitch and fin height can be easily realized. Also, compared to the conventional case where the thick heat exchange fins are welded one by one around the outer surface of the MH tank, since the heat exchange fins 1b of the present invention are thin plates, the welding work is remarkably performed. As a result, the number of steps can be reduced.

The external heat transfer medium passage 2 is provided so as to surround the outside of the MH tank 1 so that the heat transfer medium can sufficiently contact the outer surface of the MH tank 1. This is a passage through which a heat transfer medium for exchanging the heat is passed. In the present embodiment, the passage is circular, but the shape of the passage is not particularly limited as long as the heat transfer medium can sufficiently contact the outer surface of the MH tank 1.

The hydrogen storage and storage device of the present invention configured as described above
The operation of the supply device when storing hydrogen will be described. (1) A heat transfer medium (for example, cooling water of a fuel cell or a refrigerant such as outside air sent by a fan or the like) flows through an external heat transfer medium passage 2 surrounding the MH tank 1. (2) Hydrogen gas adjusted to a predetermined pressure by a filling means from a high-pressure hydrogen source (not shown) is introduced into the hydrogen storage alloy 1d through the hydrogen inlet 1a. (3) At this time, the hydrogen storage alloy 1d generates heat because the metal hydride generation reaction is an exothermic reaction. However, by providing the modulation structure fin of the present invention on the outer peripheral surface of the MH tank 1, the hydrogen storage alloy 1d moves from upstream to downstream. Thus, even if the temperature of the refrigerant rises, the hydrogen storage alloy 1d is uniformly cooled as a whole. (4) Since the hydrogen storage alloy 1d is uniformly cooled as a whole, the storage capacity of the hydrogen storage alloy 1d can be sufficiently utilized.

By providing a plurality of blocks of the heat exchange layer 1c having the plurality of heat exchange fins 1b in this manner, the heat transfer area increases stepwise from the upstream side to the downstream side of the flow of the refrigerant as the heat transfer medium. In the MH tank 1 formed so that
FIG. 2 shows the results of the refrigerant temperature and the amount of heat released from each part when hydrogen was absorbed. The vertical axis in FIG. 2 indicates the temperature (° C.) of the refrigerant and M
Surface heat release from the outer surface of the H tank 1 to the refrigerant (J / s
ec), and the horizontal axis in FIG. 2 indicates the distance from the end face to the other end face of the packed layer of the hydrogen storage alloy 1d on the side where the refrigerant is introduced into the MH tank 1 (based on the hydrogen inlet of the hydrogen storage alloy packed layer. Distance). As can be seen from FIG. 2, since the MH tank 1 is uniformly cooled, (1) the refrigerant temperature is conventionally curved (as shown in FIG. 2) as the distance from the hydrogen inlet of the hydrogen storage alloy packed bed becomes larger. In contrast, in the present invention, the temperature rises linearly. (2) In addition, the amount of heat released from the outer surface of the MH tank 1 to the refrigerant (surface heat release) conventionally has an exponential function (convex downward) as the distance from the hydrogen inlet of the hydrogen storage alloy packed layer increases. In contrast, in the present invention, the heat is radiated almost uniformly regardless of the distance from the hydrogen inlet of the hydrogen storage alloy packed layer. In this manner, even if the metal hydride generation reaction is an exothermic reaction, the entire hydrogen storage alloy 1d is uniformly cooled by the refrigerant, so that the utilization efficiency of the hydrogen storage alloy can be improved. As a result, since the entire hydrogen storage alloy can be used uniformly without forming a complicated external refrigerant passage as in the related art, the heat exchange efficiency is improved, the hydrogen storage time is reduced, and the hydrogen storage amount is reduced. Increase can be achieved.

When hydrogen is stored in the hydrogen-absorbing alloy 1d and then supplied to a fuel cell or the like, when the hydrogen is stored in the hydrogen-absorbing alloy 1d, the refrigerant used as the heat transfer medium at the time of storage is used.
Hydrogen can be released by heating the hydrogen storage alloy 1d instead of a heat transfer medium for heating d (for example, a heating medium such as cooling water or outside air heated by waste heat of a fuel cell). In this case, since the hydrogen storage alloy can be heated uniformly as in the case of hydrogen storage, the heat exchange efficiency is improved, so that the hydrogen in the hydrogen storage alloy can be used uniformly.

The hydrogen storage / supply device of the first embodiment is
A plurality of heat exchange layers 1c formed of a plurality of heat exchange fins 1b are provided on the outer periphery of the H tank 1, and the heat transfer area is stepwise for each block as going from the upstream side to the downstream side of the refrigerant flow as the heat transfer medium. This is an external cooling type hydrogen storage / supply device which is provided so as to be large in size, and which exchanges heat by flowing a refrigerant through an external heat transfer medium passage provided outside thereof. The hydrogen storage / supply device of the two embodiments described below is an internal cooling type hydrogen storage / supply device.

First, a hydrogen storage / supply device according to a second embodiment will be described with reference to the drawings. As shown in FIG. 3A, the hydrogen storage / supply device of the second embodiment stores and heats hydrogen by cooling a hydrogen storage alloy 10d housed in a tank having at least a hydrogen inlet 10a. MH tank 10 for releasing hydrogen by the
A pipe 10c serving as an internal heat transfer medium passage of a heat transfer medium penetrating in the longitudinal direction of the MH tank 10 in the tank 10
And a heat exchange fin 10b for exchanging heat with the hydrogen storage alloy 10d.

The MH tank 10 has a hydrogen storage alloy 1 therein.
This is a cylindrical pressure vessel containing Od, and a hydrogen inlet 10a is provided upstream of the flow of the heat transfer medium. The hydrogen inlet 10a is a pipe for introducing a hydrogen gas into the hydrogen storage alloy 10d from a high-pressure hydrogen source (not shown) via a filling means. The hydrogen outlet of the MH tank 10 can also serve as the hydrogen inlet 10a, or can be provided as a separate pipe.

The heat exchange fins 10b are arranged such that the heat transfer area on the downstream side in the flow direction of the heat transfer medium is larger than that on the upstream side along the circumferential direction of the outer surface of the pipe 10c serving as the internal heat transfer medium passage. Fin-shaped protrusions of the same height provided. As can be seen from FIG. 3, the plurality of heat exchange fins 10b are provided such that the fin density is high on the upstream side in the flow direction of the heat transfer medium and high on the downstream side. As a method of increasing the fin density, the fin pitch of fins of the same size attached per unit length in the longitudinal direction of the pipe 10c is changed from the upstream side to the downstream side as going from the upstream side to the downstream side in the flow direction of the refrigerant. The height of the heat exchange fins 10b may be increased as going from the upstream side to the downstream side in the flow direction of the refrigerant. These may be performed together. In the present embodiment, the shape of the heat exchange fins 10b is a disk-shaped fin, but may be a fin such as a circle, a square, a triangle, or a pin. The heat exchange fins 10b are erected by welding or brazing along the outer periphery of the pipe 10c. In the case of brazing, it can be attached in the same manner as in the hydrogen storage / supply device of the first embodiment.

By providing a large number of heat exchange fins on the downstream side in the flow direction of the heat transfer medium rather than on the upstream side,
Since the heat transfer area on the downstream side can be increased, the heat exchange efficiency on the downstream side can be increased. As a result, the overall heat transfer performance can be improved as compared with the case where heat exchange fins of the same shape are attached at a fixed fin pitch.

The pipe 10c, which is an internal heat transfer medium passage, is a circular straight pipe through which the heat transfer medium flows, and penetrates substantially the center of the MH tank 10. Hydrogen storage alloy 10d
A heat exchange fin 10b in the shape of a disk is attached to the outer surface in the circumferential direction so that heat can be sufficiently transferred.

The operation of the thus configured hydrogen storage / supply device of the second embodiment will be described. Note that, as in the case of the operation of the hydrogen storage / supply device of the first embodiment, only the operation at the time of storing hydrogen will be mainly described. (1) A heat transfer medium (for example, a coolant such as outside air sent by a cooling water of a fuel cell or a fan or the like) flows through a pipe 10c which is an internal heat transfer medium passage. (2) Hydrogen gas adjusted to a predetermined pressure by a filling means from a high-pressure hydrogen source (not shown) is introduced into the hydrogen storage alloy 10d through the hydrogen inlet 10a. (3) At this time, the hydrogen occluding alloy generates heat because the metal hydride generation reaction is an exothermic reaction. However, by providing many heat exchange fins 10b downstream from the upstream in the flow direction of the heat transfer medium, The hydrogen storage alloy 1d is uniformly cooled as a whole. (4) Since the hydrogen storage alloy 10d is uniformly cooled as a whole, the storage capacity of the hydrogen storage alloy 10d can be sufficiently utilized. By providing a large number of heat exchange fins 10b on the downstream side in the flow direction of the heat transfer medium rather than on the upstream side, the heat transfer area on the downstream side can be increased, so that the heat exchange efficiency on the downstream side is increased. can do. As a result, the heat transfer performance can be improved as compared with the case where the heat exchange fins 10b having the same shape are attached at a constant fin pitch.
Further, since the entire hydrogen storage alloy can be used uniformly, the heat exchange efficiency is improved, and the hydrogen storage time can be shortened and the hydrogen storage amount can be increased.

When hydrogen is stored in the hydrogen storage alloy 10d and then supplied to a fuel cell or the like,
The refrigerant which is a heat transfer medium used at the time of occlusion is changed to a heat transfer medium for heating the hydrogen storage alloy 10d (for example, a heat medium such as cooling water or outside air heated by waste heat of a fuel cell), and the hydrogen storage alloy is used. By heating 10d, hydrogen can be released. In this case, since the hydrogen storage alloy 10d can be uniformly heated as in the case of hydrogen storage, the heat exchange efficiency is improved, so that the hydrogen in the hydrogen storage alloy can be used uniformly.

FIG. 3B shows a hydrogen storage / supply device according to another embodiment (a modification of FIG. 3A) having the same operation and effect as the hydrogen storage / supply device of the second embodiment. Show. In this hydrogen storage / supply device, as shown in FIG. 3B, the pipe 10c which is the internal heat transfer medium passage of FIG. It shows a bent shape to allow contact. The point that many heat exchange fins are provided on the downstream side of the upstream side in the flow direction of the heat transfer medium is the same as the hydrogen storage / supply device of the second embodiment. Therefore, the heat transfer area on the downstream side can be increased, and the heat exchange efficiency on the downstream side can be increased. As a result, the heat transfer performance as a whole can be improved as compared with the case where the heat exchange fins are attached at a constant fin pitch.

Next, a hydrogen storage / supply device according to a third embodiment will be described with reference to the drawings. As shown in FIG. 4A, the hydrogen storage / supply device of the third embodiment stores hydrogen by cooling at least a hydrogen storage alloy 20d housed in a tank having a hydrogen inlet 20a, and heats the alloy. An MH tank 20 that releases hydrogen by being attached to the outer peripheral surface of a pipe 20c that is an internal heat transfer medium passage of a heat transfer medium that penetrates the MH tank 20 in the longitudinal direction of the MH tank 20; The hydrogen storage alloy 20
d and a heat exchange fin 20b for exchanging heat constitute a main part.

The MH tank 20 has a hydrogen storage alloy 2
This is a cylindrical pressure vessel containing Od, and a hydrogen inlet 20a is provided upstream of the flow of the heat transfer medium. The hydrogen inlet 20a is a pipe for introducing a hydrogen gas into the hydrogen storage alloy 20d from a high-pressure hydrogen source (not shown) via a filling means. When releasing the occluded hydrogen from the MH tank 20, the hydrogen inlet 20a can be used also as a hydrogen outlet for discharging hydrogen, or a separate pipe from the hydrogen inlet 20a may be provided. it can.

The heat exchange fins 20b are erected along the circumferential direction of the pipe 20c as the internal heat transfer medium passage so that the heat transfer area on the downstream side in the flow direction of the heat transfer medium is larger than that on the upstream side. Fin-like projections. That is, the heat exchange fins 20b are provided such that the height of the heat exchange fins 20b is higher on the downstream side than on the upstream side as going from the upstream side to the downstream side of the flow of the heat transfer medium. Further, the fin pitch is constant in the present embodiment. As can be seen from FIG. 4, the plurality of heat exchange fins 20b are provided so that the fin density is high on the upstream side in the flow direction of the refrigerant and high on the downstream side. As a method of increasing the fin density, as the heat transfer medium flows from the upstream side to the downstream side in the flow direction, the pipe 20 c
The fin pitch of the fins of the same shape attached per unit length in the longitudinal direction may be shortened from the upstream side to the downstream side as in the hydrogen storage / supply device of the second embodiment, The height of the heat exchange fins 20b may be increased from the upstream side to the downstream side in the flow direction of the medium (this embodiment). These may be performed together. In the present embodiment, the shape of the heat exchange fins 20b is a disk-shaped fin, but is circular, square, triangular,
It may be a pin-shaped fin or the like. Heat exchange fins 20b
Is erected by welding or brazing along the outer periphery of the pipe 20c. In the case of brazing, it can be mounted in the same manner as in the case of the hydrogen storage / supply device of the first embodiment.

By providing the heat exchange fins 20b such that the height of the heat exchange fins 20b becomes higher toward the downstream side than the upstream side in the flow direction of the heat transfer medium, the heat transfer area on the downstream side can be increased. Therefore, the heat exchange efficiency on the downstream side can be increased. As a result, the heat transfer performance can be improved as compared with the case where fins having the same shape are attached at a constant fin pitch.

The pipe 20 c serving as an internal heat transfer medium passage is a circular straight pipe through which the heat transfer medium flows, and penetrates substantially the center of the MH tank 20. Hydrogen storage alloy 20d
A heat exchange fin 20b in the shape of a disk is attached to the outer surface in the circumferential direction so that heat can be sufficiently transferred.

The operation of the thus configured hydrogen storage / supply device of the third embodiment will be described. As in the case of the operation of the hydrogen storage / supply device of the second embodiment, only the operation at the time of storing hydrogen will be mainly described. (1) A heat transfer medium (for example, a coolant such as outside air sent by a cooling water of a fuel cell or a fan or the like) flows through the pipe 20c serving as an internal heat transfer medium passage. (2) Hydrogen gas adjusted to a predetermined pressure by a filling means from a high-pressure hydrogen source (not shown) is introduced into the hydrogen storage alloy 20d via the hydrogen inlet 20a. (3) At this time, the hydrogen occluding alloy 20d generates heat because the metal hydride generation reaction is an exothermic reaction. However, the height of the heat exchange fins 20b increases toward the downstream side from the upstream side in the flow direction of the heat transfer medium. By preparing to be high,
The hydrogen storage alloy 20d in the MH tank 20 is uniformly cooled as a whole. (4) Since the hydrogen storage alloy 20d is uniformly cooled as a whole, the storage capacity of the hydrogen storage alloy 20d can be sufficiently utilized. By providing the heat exchange fins 20b having a higher height on the downstream side than on the upstream side in the flow direction of the heat transfer medium, it is possible to increase the heat transfer area on the downstream side.
The heat exchange efficiency on the downstream side can be increased. As a result, the heat transfer performance can be improved as compared with the case where fins having the same shape are attached at a constant fin pitch.
Further, since the entire hydrogen storage alloy can be used uniformly, the heat exchange efficiency is improved, and the hydrogen storage time can be shortened and the hydrogen storage amount can be increased.

When hydrogen is stored in the hydrogen storage alloy 20d and then supplied to a fuel cell or the like,
The refrigerant which is a heat transfer medium used at the time of storage is changed to a heat transfer medium for heating the hydrogen storage alloy 20d (for example, a heat medium such as cooling water or outside air heated by waste heat of a fuel cell) and the hydrogen storage alloy is used. By heating 20d, hydrogen can be released. In this case, since the hydrogen storage alloy 20d can be heated uniformly as in the case of hydrogen storage, the heat exchange efficiency is improved, and the hydrogen in the hydrogen storage alloy can be used uniformly.

FIG. 4B shows a hydrogen storage / supply device according to another embodiment (a modified example of FIG. 4A) having the same operation and effect as the hydrogen storage / supply device of the third embodiment. Show. In this hydrogen storage / supply device, as shown in FIG. 4B, the pipe 20c which is the internal heat transfer medium passage in FIG. It is bent so that it can make contact. It is the same as the hydrogen storage / supply device of the third embodiment in that heat exchange fins having a height higher than the upstream side are provided downstream of the upstream side in the flow direction of the heat transfer medium. Therefore, the heat transfer area on the downstream side can be increased, and the heat exchange efficiency on the downstream side can be increased. As a result, the heat transfer performance can be improved as compared with the case where heat exchange fins of the same shape are attached at a constant fin pitch.

[0043]

According to the present invention having the above configuration and operation, the following effects can be obtained. (1) According to the first aspect of the invention, a hydrogen storage tank that stores hydrogen by cooling a hydrogen storage alloy housed in the tank and releases hydrogen by heating, and an external or external part of the hydrogen storage tank. Provided on at least one of the interiors,
A hydrogen storage / supply device including the hydrogen storage alloy and a heat transfer medium passage through which a heat transfer medium for transferring heat is provided, wherein the hydrogen storage tank has a downstream side in a flow direction of the heat transfer medium. By providing heat exchange fins such that the heat transfer area between the hydrogen storage alloy and the heat transfer medium is larger than the upstream side, without forming a complicated heat transfer medium passage, the entire hydrogen storage alloy is The heat exchange efficiency is improved because it can be used uniformly. Further, the hydrogen storage alloy is pulverized by repeating the storage and release of hydrogen, but local pulverization can be suppressed by configuring as described above. (2) According to the invention of claim 2, a plurality of heat exchange layers having heat exchange fins are provided in the traveling direction of the heat transfer medium, and when the heat transfer medium flows from the upstream side to the downstream side, turbulence is generated. By arranging the heat exchange fins of each heat exchange layer so as to generate the heat, the flow is sufficiently stirred when the heat transfer medium passes through the gap between the heat exchange fins, so that the heat exchange efficiency is further improved. (3) According to the third aspect of the present invention, a large number of heat exchange fins are provided on the downstream side in the flow direction of the heat transfer medium from the upstream side, so that the heat transfer area on the downstream side can be increased. The heat exchange efficiency on the downstream side can be increased. As a result, the heat transfer performance can be improved as compared with the case where heat exchange fins having the same shape are attached at a fixed fin pitch. (4) According to the invention of claim 4, a heat exchange fin having a height higher than the heat exchange fins on the upstream side is provided on the downstream side of the upstream side in the flow direction of the heat transfer medium. Since the heat transfer performance can be increased, the heat transfer performance can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration of a hydrogen storage / supply device of a first embodiment according to the present invention.

FIG. 2 shows the relationship between the refrigerant temperature and the M at each position of the hydrogen storage alloy during hydrogen storage of the hydrogen storage / supply device of the first embodiment.
It is a figure showing the radiation characteristic from the surface of H tank.

FIG. 3 (a) A hydrogen storage and storage device according to a second embodiment of the present invention.
It is a figure showing the whole composition of a supply device. (B) A hydrogen storage / supply device according to another embodiment having the same operation and effect as the hydrogen storage / supply device according to the second embodiment.

FIG. 4 (a) shows a hydrogen storage and storage device according to a third embodiment of the present invention.
It is a figure showing the whole composition of a supply device. (B) A hydrogen storage / supply device according to another embodiment having the same operation and effects as the hydrogen storage / supply device according to the third embodiment.

FIG. 5A is a perspective view showing a structure of a fin used for cooling or heating an MH tank of a conventional hydrogen storage / supply device. (B) It is a perspective view which shows the structure of another fin used for cooling or heating of the MH tank of the conventional hydrogen storage / supply apparatus.

FIG. 6 is a diagram showing the temperature of the refrigerant at each position of the hydrogen storage alloy and the heat radiation characteristics from the surface of the MH tank when hydrogen is stored in the conventional hydrogen storage / supply device.

[Explanation of symbols]

1,10,20 MH tank (hydrogen storage tank) 1a, 10a, 20a Hydrogen inlet (hydrogen filling path) 1b, 10b, 20b Heat exchange fin 1c Heat exchange layer 10c, 20c Pipe (internal heat transfer medium passage) 1d, 10d, 20d Hydrogen storage alloy 2 External heat transfer medium passage (passage of heat transfer medium)

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takeaki Shimada 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3E072 EA10 4G040 AA17

Claims (4)

[Claims] 1. A hydrogen storage tank that stores hydrogen by cooling a hydrogen storage alloy accommodated in the tank and releases hydrogen by heating, and is provided at least one of outside and inside of the hydrogen storage tank. A hydrogen storage medium comprising: a passage for a heat transfer medium flowing through the hydrogen storage alloy and a heat transfer medium for transferring heat.
In the supply device, the hydrogen storage tank is provided with heat exchange fins such that a heat transfer area between the hydrogen storage alloy and the heat transfer medium is larger on the downstream side in the flow direction of the heat transfer medium than on the upstream side. A hydrogen storage / supply device characterized by the following. 2. A plurality of heat exchange layers having the heat exchange fins in a traveling direction of the heat transfer medium, and each of the heat exchange layers is formed so that turbulence is generated when the heat transfer medium flows from an upstream side to a downstream side. The hydrogen storage / supply device according to claim 1, wherein heat exchange fins of the heat exchange layer are arranged. 3. The hydrogen storage / supply device according to claim 1, wherein a number of the heat exchange fins are provided on a downstream side of an upstream side in a flow direction of the heat transfer medium. 4. The heat exchange fin having a height higher than an upstream heat exchange fin at a downstream side of an upstream side in a flow direction of the heat transfer medium. The hydrogen storage / supply device according to claim 2.