JPS642870B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a portable heating/cooling device that utilizes the exothermic heat absorption accompanying the absorption and desorption of hydrogen in a metal hydride.

Conventionally, portable heating and cooling devices include a heat source method in which a hot source such as hot water or a cold source such as ice or dry ice is housed in an insulated box, and an electric method in which a Peltier element is placed in an insulated box. However, with the heat source method, you have to prepare a heat source every time you use it, which is cumbersome, and the temperature of heat sources such as hot water drops within a short period of time, and the temperature of cold sources such as dry ice decreases over time. It does not have stable heating and cooling ability because it is consumed. On the other hand, although electric systems can provide stable heating and cooling over long periods of time, they are useless outdoors where there is no power source.

In view of the above, the present inventors further proposed
Certain metals or alloys rapidly and exothermically absorb hydrogen to form metal hydrides, as described in Japanese Patent Application Laid-open No. 56181 and Japanese Patent Application Laid-Open No. 55-89691.
In addition, by focusing on heat storage materials and their usage that take advantage of the property of metal hydrides to reversibly and endothermically release hydrogen, and by improving these materials, there is no need to prepare a heat source for use. Furthermore, we have invented a portable heating and cooling device that does not require a power source and can be used for a long time.

The present invention provides a first container in which a plurality of tube-shaped containers filled with a first metal hydride are connected in parallel, and the first container is disposed within an insulating box so as to exchange heat with the space inside the insulating box. In a portable heating/cooling device in which a second container filled with the metal hydride of No. 2 is disposed outside the insulation box, and the two containers are connected by a communicating pipe equipped with a valve, the insulation box The present invention is characterized in that it has a temperature sensor that detects the temperature inside the heat insulating box, and the opening and closing of the valve is controlled according to the temperature inside the heat insulating box.

The present invention will be described below based on drawings showing examples.

FIG. 1 shows an embodiment of the portable heating and cooling device of the present invention, in which a heat insulating box 1 consists of a cover 2 and a main body 3 that can be opened and closed, and a first metal hydride is contained in the heat insulating box.
A first container 4 filled with M ₁ H is disposed and exchanges heat with a storage space 5 for a heated and cooled object in the main body. Note that the first container may be disposed at an appropriate position within the heat insulating box so as to be able to exchange heat with the storage space. On the other hand, a container 6 filled with a second metal hydride M ₂ H is disposed outside the heat-insulating box, for example, on the outside of the lid, the side wall of the main body, and the outer wall of the bottom surface.

The first and second containers are connected via filters 7 and 8, respectively, to a communication pipe 9, which is equipped with a valve 10. As will be explained later, the valve is opened to allow hydrogen to flow between the containers, allowing the metal hydride to absorb and release hydrogen. The filter prevents metal hydrides from being entrained during the hydrogen flow and from clogging the communication pipes and valves. For example, a porous sintered metal with a pore diameter of 10 μm or less is preferably used as the filter.

The first container is made up of a plurality of tube-shaped containers connected in parallel by a communicating pipe. Further, the second container is preferably tube-shaped, and more preferably, like the first container, it is formed from a plurality of tube-shaped containers, which are connected in parallel to a communicating pipe. be. The first and second containers are also preferably removably attached to the insulated box, and the communicating tube is preferably flexible.

A temperature sensor 11 is installed inside the insulation box or inside the first container.
The valve is opened and closed depending on the temperature detected by the temperature sensor, and the flow rate of hydrogen passing through the valve is controlled. Valve opening/closing control uses pneumatic, hydraulic,
Although auxiliary means such as electromagnetism may be used, it is preferable to convert temperature directly into pressure by utilizing expansion of materials such as metals or changes in pressure within the container, and use this pressure to open and close valves. It is convenient to use a so-called self-acting control valve.

M ₁ H and M ₂ H may have the same or different equilibrium decomposition pressure characteristics, but preferably those that are different from each other are used. It is advantageous for the equilibrium decomposition pressure to be less than 10 atm in the heating and cooling temperature range for wall fabrication and equipment use. Specifically, for example, LaNi ₅ hydride-CaNi ₅ hydride, MmNi _5-x Al _x -CaNi ₅ ,
A combination such as MmNi _5-x Al _x -LaNi ₅ (0x0.5) is used.

When the device of the present invention is used as a cooling device, as shown in FIG.
M ₁ H, which has a high equilibrium decomposition pressure at T _M , is filled in a high-pressure hydrogen atmosphere, and M ₂ H, which has a low equilibrium decomposition pressure at room temperature, is preferably filled with low-pressure hydrogen in a metallic state that has released hydrogen. Filled under atmosphere. That is, the state of M ₁ H corresponds to point B, and the state of M ₂ H corresponds to point D, respectively.

If the operating temperature of the temperature sensor is set to the required cooling temperature T _L inside the insulation box, the valve will be opened until the temperature inside the insulation box reaches the set temperature, and the first and second containers will communicate with each other. Hydrogen moves from the first vessel at high pressure to the second vessel at low pressure, and M ₁ H emits hydrogen endothermically to reach the temperature T _L and cool the inside of the insulated box. On the other hand, M ₂ H absorbs hydrogen and generates heat,
This heat is dissipated into the atmosphere through the second container wall. When the temperature inside the insulated box reaches the set temperature, a temperature sensor is activated to close the valve and the flow of hydrogen between the containers is interrupted. After this, when the temperature inside the insulation box rises above a predetermined temperature, the temperature sensor is activated again and the inside of the insulation box is cooled down to the predetermined temperature. In this way, the inside of the insulated box is maintained at a predetermined temperature as long as a hydrogen pressure difference exists between the containers.

When the device of the present invention is used as a heating device, contrary to the above, M ₁ H is filled in the second container under a high pressure hydrogen atmosphere, and M ₂ H is filled in the first container under a low pressure hydrogen atmosphere. is filled with. Until the inside of the insulated box reaches the required heating temperature, the valve is opened and the two containers are communicated, hydrogen flows from the second container to the first container, and the M ₂ H in the first container heats the hydrogen. The heat is stored inside the insulated box.

After performing the heating and cooling operation as described above,
To return the metal hydride in each container to its original state and prepare it for reuse, for example, open the valve.
By heating M ₂ H and increasing its equilibrium decomposition pressure while keeping M ₁ H at room temperature, hydrogen is released from M ₂ H, which is stored in M ₁ H, and then the valve is closed. Alternatively, while reducing the pressure of M ₂ H,
Hydrogen may be supplied to M ₁ H under pressure.

A specific example will be explained. Inner diameter 300×200×150mm,
Using an insulated box with an internal volume of 9, there is 1030g inside the insulated box.
The first container consists of multiple tube-shaped containers filled with LaNi ₅ , and 1280 g of LaNi 5 is placed outside the insulated box.
A second container filled with CaNi ₅ is arranged, and the first container is pressurized to 2 atm at a temperature of 30°C to store hydrogen up to 80% of the maximum storage capacity. , reduce the hydrogen pressure to 0.7 atm at a temperature of 30℃,
Hydrogen was released until the hydrogen storage amount reached 20% of the maximum amount.

When the temperature of the gas expansion self-operating control valve is set to 20℃ relative to the outside temperature of 30℃, and it is connected to the temperature sensor placed inside the insulation box, the temperature inside the insulation box will increase after about 15 minutes as shown in Figure 3. The temperature inside the insulated box was maintained at approximately 20°C for about 6 hours.

As described above, the portable heating/cooling device of the present invention utilizes the hydrogen absorption/desorption reaction of metal hydrides, so it can heat or cool without requiring any power source, and can maintain the required temperature inside the insulation box. Since the flow rate of hydrogen is controlled by opening and closing the valve using a sensor, the inside of the insulating box can be kept at the required temperature and can be used for a long time while being carried.Furthermore, the first container of the present invention It consists of multiple tube-shaped containers that can be filled with metal hydride in parts, so it has good pressure resistance even if the walls of each container are thin, and the device is lightweight for easy portability. This is an effective method for

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the portable heating/cooling device of the present invention, Fig. 2 is a graph showing the equilibrium decomposition pressure characteristics of metal hydride to explain its operation, and Fig. 3 is the cooling device. It is a graph which shows an example of the time-dependent change of the temperature in a heat insulating box when it is used as a heat insulating box. 1...insulation box, 4...first container, 6...second
container, 9... communication pipe, 10... valve, 11... temperature sensor.

Claims (1)

[Claims] 1 A first container formed by connecting a plurality of tubular containers filled with a first metal hydride in parallel is disposed within an insulating box so as to exchange heat with the space inside the insulating box, and a second metal hydride is filled with a first metal hydride. In a portable heating/cooling device in which a second container filled with hydride is disposed outside the insulated box and the two containers are connected by a communicating pipe equipped with a valve, the temperature inside the insulated box is 1. A portable heating/cooling device, comprising: a temperature sensor for detecting temperature, and the valve is controlled to open and close according to the temperature inside the heat insulating box.