JP2000111193A - Hydrogen occlusion alloy heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high heat transfer performance while reducing the weight and size by laminating a plurality of corrugated plates orthogonally, obliquely or in parallel each other through flat plates thereby forming a section to be filled with a hydrogen occlusion alloy and a channel for heat exchanging medium. SOLUTION: A heat exchanging section comprises channels for heat exchanging medium 1, 1', 1", and sections to be filled with a hydrogen occlusion alloy 2, 2'. Corrugated plates 3, 3', 3" forming the channels for heat exchanging medium are arranged orthogonally to the corrugated plates 4, 4' forming the sections to be filled with a hydrogen occlusion alloy and they are laminated through flat plates 5, 5', 5", 5"'. The corrugated plates 3, 3" on the uppermost and lowermost stages form the channels 1, 1" for heat exchanging medium, respectively, by arranging flat plates 6, 6' oppositely to the side touching the flat plates 5, 5"'. Each corrugated plate and each flat plate are jointed integrally by welding, or the like. The arrow indicates the flowing direction of heat exchanging medium. According to the structure, high heat transfer performance can be ensured while reducing the weight and size and facilitating manufacture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an efficient heat exchanger for utilizing a hydrogen storage alloy, and particularly requires an efficient heat exchange such as a heat pump, heat storage, a hydrogen vehicle, and a fuel cell. It is suitable for use in the field.

[0002]

2. Description of the Related Art Hydrogen storage alloys have a wide range of applications such as storage and transport of hydrogen, heat pumps, heat storage, purification and separation of hydrogen, and production of hydrocarbons. Many suggestions have been made.

Among the heat exchangers, a hydrogen storage alloy is filled in a cylindrical pressure-resistant tube, and a cooling medium or a heating medium is passed through the outside of the tube. A type in which a cooling medium or a heating medium is filled and a cooling medium or a heating medium is passed through a pipe is known, and the storage medium is switched between the cooling medium and the heating medium at regular time intervals to store and release hydrogen.

[0004] Incidentally, since the tube-filled type has a problem in heat transfer efficiency, a heat transfer fin or a baffle is provided outside the tube to improve the heat transfer performance of the heat exchange medium, or the inside of the tube is not provided. A heat transfer fin is provided in the hydrogen storage alloy filling layer, or a heat transfer promoting member such as a metal sponge or a metal mesh is arranged.

[0005] On the other hand, in a general cylindrical hydrogen storage alloy heat exchanger, it is necessary to reduce the thickness of the hydrogen storage alloy layer in order to improve the heat transfer. The amount of filling per bottle is reduced, and the number of tubes must be increased to compensate for this, which inevitably increases the weight. Also, when attaching heat transfer fins, it is necessary to increase the thickness to a certain extent in order to secure strength, which limits the weight reduction, and arranges heat transfer promotion members such as metal sponge and metal mesh. In such a case, it is difficult to obtain a lightweight, inexpensive material having good heat transfer performance, and it is difficult to increase the adhesion between these members and the tube wall, and thus there are many practical problems.

Further, in order to alternately store and release hydrogen, it is necessary to alternately supply a cooling medium or a heating medium to the outer vessel. However, in the conventional cylindrical heat exchanger, the body side is changed. Since it is structurally difficult to reduce the flow rate, the flow velocity decreases and the heat transfer coefficient cannot be increased. Attempts have been made to provide a baffle to improve this, but in this case, the sensible heat taken by the baffle itself increases, resulting in a decrease in thermal efficiency.

Further, since the cylindrical heat exchanger has a large residence volume on the shell side, it takes a long time to switch or exchange the cooling medium and the heating medium, and a large sensible heat loss is caused by mixing the cooling medium and the heating medium. There was also a disadvantage. For these reasons, in order to improve the heat transfer performance, the cylindrical heat exchanger had to sacrifice weight reduction, and the use range of the heat exchanger was inevitably limited.

[0008]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional cylindrical hydrogen storage alloy heat exchanger and provides a heat exchanger having a high heat transfer performance and a structure capable of reducing the size and weight. It was made for the purpose of providing.

[0009]

Means for Solving the Problems The present inventors have conducted various studies on a heat exchanger for utilizing a hydrogen storage alloy. A structure in which hydrogen storage alloy is filled in units having the same waveform direction, and a unit in a direction perpendicular, oblique or parallel to the medium passage is formed. As a result, it has been found that the heat transfer efficiency can be improved and the weight can be reduced, and the present invention has been made based on this finding.

That is, the present invention relates to a hydrogen storage alloy filled portion formed by laminating a plurality of corrugated plates via a flat plate such that adjacent corrugated plates are orthogonal, oblique or parallel to each other, and a portion adjacent to the hydrogen storage alloy filled portion. And an orthogonal, oblique or parallel heat exchange medium flow path, a hydrogen gas inlet and an exhaust port connected to the hydrogen storage alloy filling portion via a filter plate, respectively, and a heat exchange medium introduction connected to the heat exchange medium flow path An object of the present invention is to provide a hydrogen storage alloy heat exchanger, comprising: a port, a discharge port, and a hydrogen storage alloy filled in the hydrogen storage alloy filling section.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the heat exchanger of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view for explaining a main part of an orthogonal type of a heat exchanger of the present invention, wherein a heat exchange part includes heat exchange medium flow paths 1, 1 ', and 1 ".
And a hydrogen storage alloy filling section 2, 2 '. The corrugated plates 3, 3 ', 3 "forming the heat exchange medium flow path and the corrugated plates 4, 4' forming the hydrogen storage alloy filling portion are arranged so as to be orthogonal to each other, and the flat plates 5, 5 ', 5 ", 5"", and the uppermost and lowermost corrugated plates 3, 3" are placed on opposite sides of the flat plates 5 and 5 "".
The heat exchange medium channels 1, 1 "are respectively formed by disposing the flat plates 6, 6 '. Each corrugated plate and each flat plate are integrally joined by welding or the like. Arrows in the middle indicate the flow direction of the heat exchange medium.

FIG. 2 is a perspective view showing an example of the heat exchanger of the present invention in which the heat exchange section of FIG. 1 is incorporated. In this example, four heat exchange medium channels and three Side plates 9 and 9 ′ provided with a heat exchange medium inlet 7 and a heat exchange medium outlet 8 (not shown) at both ends of the heat exchange medium flow path, respectively. Filter plates 10 and 10 'are provided at both ends of the hydrogen storage alloy filling portion, respectively.
Through a hydrogen inlet 11 (not shown) and a hydrogen outlet 1
2 are provided with side plates 13, 13 '.

The material of the heat exchanger of the present invention is preferably stainless steel when strength and corrosion resistance are important, and aluminum or aluminum alloy when weight saving is important. Can also be used. Further, the numbers of the hydrogen storage alloy filling portion and the heat exchange medium flow path in the heat exchanger of the present invention are not particularly limited, and can be appropriately increased or decreased according to the purpose of use. Next, the filter plates 9, which are in contact with both ends of the hydrogen storage alloy filling section,
9 'may be any as long as it can suppress scattering of the hydrogen storage alloy powder, and is not particularly limited, but a cotton filter is suitable.

In the heat exchanger of the present invention, the hydrogen storage alloy filling portions 2, 2 ',... Are filled with the hydrogen storage alloy. The type, shape, grain size, etc. of the hydrogen storage alloy are not particularly limited. Instead, they can be appropriately selected and used according to the purpose of use. However, it is advantageous to use a fluorinated one in terms of simplification of the pressure resistance structure at the time of initial activation and stable use over a long period of time.
In order to exchange heat with the apparatus of the present invention, hydrogen gas is passed through the hydrogen storage alloy filling portion, and heat generated by hydrogen absorption is absorbed and recovered by the medium passing through the adjacent heat exchange medium flow path. Next, when the hydrogen storage alloy has finished storing hydrogen, a heating medium is passed through the adjacent heat exchange medium flow path to heat the hydrogen storage alloy to generate hydrogen, which is recovered. By repeating such an operation, cooling and heating of the medium or adsorption and desorption of hydrogen can be performed according to the purpose. When the hydrogen storage alloy filling section and the heat exchange medium flow path are provided in parallel, it is advantageous to operate the hydrogen gas flow and the heat exchange medium in countercurrent.

In the heat exchanger of the present invention, each of the hydrogen storage alloy filling portions is filled with a hydrogen storage alloy having a different characteristic, and a heat exchange medium having a different temperature is passed through a heat exchange medium flow path adjacent to the heat storage medium. In such a system in which hydrogen moves between two or more types of metal hydrides, complicated connection by piping can be omitted. Also, by measuring the pressure fluctuation on the hydrogen storage alloy side and forcibly controlling the pressure on the heat exchange medium side to be the same as the hydrogen pressure following the hydrogen pressure, the pressure applied to the flat plate can be reduced. Therefore, there is an advantage that the thickness of the flat plate can be reduced to reduce the weight.

[0016]

Next, the present invention will be described in more detail by way of examples.

EXAMPLE In the hydrogen storage alloy heat exchanger having the structure shown in FIG. 2, the height of the hydrogen storage alloy side was 30 mm, the wall thickness was 0.5 mm, and the pitch was 5 mm.
mm, a height of 5 mm on the heat exchange medium side, a thickness of 0.5 mm, a pitch of 5 mm, a corrugated plate having a heat exchange medium passage on the outermost side, and a hydrogen storage alloy filling portion provided inside the heat exchange medium passage. A five-stage laminated structure in which a heat exchange medium passage was further provided between the portions was formed. The material was all made of aluminum, the external dimensions were 90 mm in height, 150 mm in width, and 200 mm in length. The design conditions were a pressure resistance of 10 atm, a normal temperature of 100 ° C. or less, and a lanthanum-nickel-aluminum-based fluorinated hydrogen storage alloy of 7 kg was charged into the alloy filling portion, and the following experiment was performed. As a result of initial activation by pressurizing hydrogen at 7 atm while flowing cooling water at 25 ° C, the reaction between hydrogen and the fluorinated hydrogen storage alloy started 1 minute after the introduction of hydrogen, and completely completed in 10 minutes. The occlusion was completed. After that, hot water of 80 ° C. is flowed to release hydrogen, and 25
Tables 1 and 2 show the results of occlusion of hydrogen by flowing cooling water at ° C.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

The heat exchanger of the present invention has the advantages that it exhibits high heat transfer performance, can be reduced in weight and size, and can be easily manufactured. In addition, when used in a device that transfers hydrogen between different types of hydrogen storage alloys, such as a heat pump, the heat absorption part and the heat generation part are integrated by filling the filling part with hydrogen storage alloys with different characteristics, simplifying the structure. There are also advantages.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a heat exchanger of the present invention.

FIG. 2 is a perspective view of an example of the heat exchanger of the present invention.

[Explanation of symbols]

 1, 1 ', 1 "heat exchange medium flow path 2, 2' hydrogen storage alloy filling part 3, 3 ', 3", 4, 4' corrugated plate 5, 5 ', 5 ", 5"', 6, 6 ″ Flat plate 7 Heat exchange medium inlet 8 Heat exchange medium outlet 9, 9 ′, 13, 13 ′ Side plate 10, 10 ′ Filter plate 11 Hydrogen inlet 12 Hydrogen outlet

Claims (4)

[Claims] 1. A hydrogen-absorbing alloy-filled portion formed by laminating a plurality of corrugated plates via a flat plate such that adjacent corrugated plates are perpendicular to each other, obliquely or parallel to each other, and a plurality of corrugated plates adjacent to the hydrogen-absorbing alloy. Crossed or parallel heat exchange medium channels, hydrogen gas inlets and outlets connected to the hydrogen storage alloy filling section through filter plates, respectively, and heat exchange medium inlets and outlets connected to the heat exchange medium channels. And a hydrogen storage alloy filled in the hydrogen storage alloy filling section. 2. The hydrogen storage alloy heat exchanger according to claim 1, wherein an opening is provided in the corrugated plate forming the hydrogen storage alloy filling portion. 3. The hydrogen storage alloy heat exchanger according to claim 1, wherein a plurality of different hydrogen storage alloy filling portions are filled with different hydrogen storage alloys. 4. The hydrogen storage alloy heat exchanger according to claim 1, wherein the hydrogen storage alloy is a fluorinated hydrogen storage alloy.