JPH0351987B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cooling device that utilizes an endothermic exothermic cycle between a plurality of hydrogen storage alloys. It is known that certain metal hydrides absorb and release hydrogen reversibly and generate heat and endotherm during this process. The reaction in this case is expressed by the following equation. MH(m+n)MHm+n/2H ₂ ±ΔH where M is a metal capable of occluding hydrogen, n and m are the number of hydrogen atoms to be occluded, and ΔH is the heat of reaction. Examples of such metal hydrides that can absorb hydrogen include lanthanum-nickel hydride, mitsu metal-nickel hydride, vanadium-niobium hydride, iron-titanium hydride, titanium-manganese hydride, and lanthanum-cobalt hydrogen. Examples include magnesium oxide, magnesium-copper hydride, magnesium-nickel hydride, and the like. These metal hydrides each have different temperature-hydrogen pressure equilibria, so by combining multiple of these metal hydrides, hydrogen can be exchanged reversibly between them, and the resulting heat absorption and heat generation can be utilized. , cooling and heating are proposed. FIG. 1 shows the temperature for metal hydrides A and B.
This is a graph showing the hydrogen pressure equilibrium state. Metal hydrides A and B are filled in separate heat exchangers and connected through a hydrogen pipe, and A is brought to a temperature of Tl and B to a temperature of Tm. When kept, hydrogen is released from A and absorbed by B, and A also absorbs heat Q ₁ . When hydrogen is completely absorbed by B, when the temperature of B is raised from Tm to Tk and A is raised to Tm,
This time, hydrogen is released from B, which flows to A and is absorbed. By repeating such operations, heating and cooling can be achieved synchronously. As a device utilizing such a principle, a heating and cooling device of the type shown in outline in FIG. 2 has been proposed (Japanese Patent Publication No. 19955/1983). This device connects containers A, B, C, and D, each of which has a hydrogen storage alloy sealed inside, with a pipe, and the containers A and C are equipped with a heater H and a heat radiation fan, and the containers B and D are equipped with a cooling water pipe G and a heat radiation fan. First, when the container (A) is heated via the heater (1) to increase the pressure inside the container, hydrogen is released, and at the same time, hydrogen is occluded in the container (2). In this case, the container is cooled by a cooling water pipe and a fan. When all the hydrogen in container A has been transferred to container B in this way, it is cooled in the fan, and at the same time, the hydrogen is switched to containers C and D, and the same operation is repeated. In this way, two sets of devices can be used alternately to provide cooling or heating. However, in such a device, the heat radiation and heat absorption generated by repeatedly transferring hydrogen between two containers that form a pair are simply used to create a cooling or heating state, so it is not possible to provide appropriate cooling or heating. In order to perform heating, there are restrictions on the types and combinations of hydrogen storage alloys, and it is also extremely difficult to control the operation, and there are still many problems that need to be solved before it can be put into practical use. The inventors of the present invention have conducted intensive research to overcome the problems of conventional devices and develop a cooling device using a hydrogen storage alloy that can be easily put into practical use. The present inventors have discovered that the objective can be achieved by combining heat absorption systems and making each of them switchable by a damper, and have come up with the present invention. That is, the present invention provides a series of air pipes that mutually penetrate through the heat exchanger of each container to heat or radiate heat, and several dampers are provided in this series of pipes to heat and radiate heat. The drawbacks of the above-mentioned device have been eliminated by mutually adjusting the cooling, and by using a porous metal body for the hydrogen storage alloy and combining this with a filter to achieve efficient heat exchange. An embodiment of this invention will be explained with reference to the drawings.
As shown in Figure 3, two sets of heat exchangers A, B, C, and D each containing two types of hydrogen storage alloys are connected by hydrogen pipes 1 and 2, respectively. At the same time, these heat exchangers A, B,
Air pipes 3a, 3b, 3c passing through C and D,
The air pipes 3a and 3c have their proximal ends connected to each other by pipes 4 and 5, one of which is connected to a heating air pipe 6 for supplying high-temperature air, and the other end is open to the atmosphere. Form at the ends 7,7. The air pipes 3b and 3d have their proximal ends connected by pipes 8 and 9, one of which is connected to an air pipe 10 that extends into the room to be cooled, and the other end is connected by pipes 11 and 12. On the other hand 1
1 is connected to the cooling air pipe 13, and the other is connected to the heat radiation air pipe 14. Furthermore, connect the pipes 5 and 9 with the standpipe 15,
A heat radiation air pipe 16 is connected to this. Each of the pipes 4, 5, 8, 9, 11, and 12 has a damper a ₁ , a ₂ , c ₁ , c _{2 ,} for opening and closing the flow passage near the air pipe line, respectively.
b ₁ , b ₂ , b ₃ , b ₄ , d ₁ , d ₂ , d ₃ , and d ₄ are respectively provided. In the above apparatus, heat exchangers A, B, C, and D are filled with a porous metal body and a finely powdered hydrogen storage alloy surrounding a filter tube 17 made of a porous tube such as ceramic, as shown in FIG. It has a structure in which 18 stainless steel finned tubes 18 are bundled and housed in an outer box 19. As a hydrogen storage alloy,
Any conventionally known ones can be selected and used, but the above Th=150±30℃, Tm=25±10℃, Tl=
Considering the equilibrium value at 5±10℃, the general formula MmNi _(5-x) A _(x) ...() (where Mm is Mitsushi Metal, A is Fe or Al,
x is a number from 0.1 to 1) It is preferable to use a combination of two compounds selected from the following. This compound has A
In the case of Fe, x=0.1 to 1.0, in the case of A to Al, x=
A range of 0.1 to 0.5 is particularly preferred. In this case, Mm in the general formula () is La20~50
It is preferable that the mol% is comprised of Ce2 to 40 mol% and the remainder is Pr and Nd. It is advantageous to select a hydrogen storage alloy of 50 kcal/hour or more per kg. On the other hand, as the porous metal body, an aluminum foam or a copper foam, particularly one having a porosity of 90% or more, is suitable. The filter pipe 17 is connected to the hydrogen pipes 1 and 2, and hydrogen is introduced and discharged therethrough. In addition, the heat exchanger can have any structure, such as not only a structure in which finned tubes are bundled in parallel as shown in Figure 4, but also a structure in which they are connected in series, or a structure in which parallel and series are combined. can do. Further, each of the dampers a ₁ a ₂ . . . d ₃ , d ₄ can be externally controlled by an attached electric mechanism (not shown) in the same way as a solenoid valve. The present invention has the above-mentioned configuration, and the cooling air pipe 1
3 into the required indoor room R to be cooled, and connect the cooling air pipe 10 to the indoor exhaust port R,
In addition, the heat radiation air pipes 14 and 16 are connected to the heat radiation port F by a heat radiation fan, and the high temperature air pipe 6 is connected to an appropriate blast heater H, and each heat exchanger A and C is heated via the blast heater H. The heat dissipation air from the heat dissipation fan is sent to each heat exchanger A, B, C, and D for cooling, and each damper a ₁ a ₂ ... d ₃ , d ₄ is opened and closed as shown in the table below. By alternately using each set of heat exchangers A, B, C, and D, one for cooling and the other for regeneration, continuous cooling can be achieved.

[Table] × is closed In other words, each heat exchanger is operated to the required state by switching each damper in the above order to continuously supply high-temperature air and ventilation by a heat radiation fan. The switching of each of these dampers may be done manually, but it can also be easily done automatically by program control via a timer. As explained above, the present invention allows hydrogen to flow smoothly in the exchanger, and there is no need to unnecessarily increase the pressure in the hydrogen piping system, so there is no need to consider high pressure, reducing costs. In addition, the air temperature can be freely adjusted by remote control via a damper, and the heat exchanger structure is made of a porous metal body such as aluminum foam that encapsulates fine hydrogen storage alloy particles. Since the storage alloy is housed in the finch tube through the fin, it has many advantages, such as being efficient because it does not flow even though it has a large surface area. When the device of the present invention is used for indoor cooling, the inlet temperature of the high-temperature air should be set at about 150°C ± 30°C.
The inlet temperature of the cooling air should be 15 to 35℃, and the outlet temperature should be about 10 to 15℃ lower than the inlet temperature.
It is best to design the cycle time to be about 8 to 20 minutes.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the endothermic amount and calorific value of metal hydrides, FIG. 2 is an explanatory diagram showing an example of a conventional device, and FIG. 3 is an overall explanatory diagram showing an example of the present invention. FIG. 4 is a sectional view showing the main parts of the heat exchanger. A, B, C, D... Heat exchanger, 3a, 3b, 3
c, 3d...air pipe line, 6...heated air pipe, 7...
...Open end, 10... Indoor air pipe, 13... Cooling air pipe, 14, 16... Radiation air pipe, a ₁ , a ₂ , c ₁ ,
c ₂ , b ₁ , b ₂ , b ₃ , b ₄ , d ₁ , d ₂ , d ₃ , d ₄ ... damper, 17 ... filter, 18 ... finned tube, 19 ... outer box.

Claims (1)

[Claims] 1. In a cooling device that utilizes cold air obtained by alternately heating and cooling a set of two heat exchangers each containing hydrogen storage alloys with different compositions, The structure of the exchanger is an assembly of finned tubes in which filter tubes connected to hydrogen piping are passed through a porous metal body whose pores are filled with finely powdered hydrogen storage alloy. An air pipe is provided that passes through the device, and one end of each air pipe is connected to each other, and the inflow pipes for high temperature air, radiation air, and cooling air are connected by providing dampers at each part. A cooling device characterized in that the other ends of the passages are connected to each other and exhaust pipes for heat radiation air and cooling air are connected by providing dampers at each part, and each damper can be opened and closed by remote control. 2 As a hydrogen storage alloy, the general formula MmNi _(5-x) A _(x) (where Mm is Mitsushi Metal, A is Fe or
(Al, x is a number from 0.1 to 1.0) The cooling device according to claim 1, using two kinds of compounds selected from the following. 3 Mm is La20-50 mol%, Ce is 2-40 mol%,
3. The cooling device according to claim 2, wherein the remainder is Pr and Nd. 4. The cooling device according to claim 1, wherein the porous metal body is an aluminum foam or the other is a copper foam. 5. The cooling device according to claim 1, wherein the inlet temperature of the high-temperature air is 150±30°C. 6. The cooling device according to claim 1, wherein the inlet temperature of the cooling air is 15 to 35°C, and the outlet temperature is 10 to 15°C lower than the inlet temperature.