JPH0412380B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for obtaining cold or thermal output.

It is known that certain metals and alloys absorb hydrogen exothermically to form metal hydrides, and that these metal hydrides reversibly release hydrogen.
In recent years, methods for obtaining low-temperature or high-temperature output using such characteristics of metal hydrides have been proposed.

Figure 1 shows a first metal hydride (MH1) with a low hydrogen equilibrium decomposition pressure in the operating temperature range and a second metal hydride (MH2) with a high hydrogen equilibrium decomposition pressure in the operating temperature range. A conventional method of obtaining output is shown, where the horizontal axis shows the reciprocal of the absolute temperature T, and the vertical axis shows the logarithm of the hydrogen equilibrium decomposition pressure P of metal hydride.

That is, MH1 is heated to high temperature TH by a high temperature heating medium to release hydrogen, this hydrogen is stored in MH2 maintained at medium temperature TM, and then MH1 is heated to medium temperature TH.
Cool to TM and adjust the hydrogen equilibrium decomposition pressure of MH1 to MH
By setting the temperature lower than that of MH2 and performing a cycle in which hydrogen is endothermically released from MH2 and stored in MH1, a cold output is obtained from the low-temperature heating medium connected to MH2 in a heat exchangeable manner.

Figure 2 shows a conventional method of obtaining thermal output by a so-called counterclockwise cycle, in which MH2 is heated to medium temperature TM with a medium temperature heating medium to release hydrogen, and this hydrogen is exothermically occluded in MH1. Then, by holding MH1 at a medium temperature TM and holding MH2 at a low temperature TL to release hydrogen from MH1 and storing it in MH2, the hydrogen was connected to MH1 for heat exchange during the exothermic reaction of MH1. It obtains thermal output from a high-temperature heating medium.

In terms of equipment, this method usually involves filling MH1 and MH2 into sealed containers, connecting each container to a heating medium at a predetermined temperature for heat exchange, and alternately heating each container to a predetermined temperature. At the same time, by connecting the containers with a hydrogen communication pipe with an on-off valve and opening and closing them in synchronization with the heating and cooling of each container by the heating medium, a specified amount of cold heat is generated from the specified heating medium. Or obtain thermal output.

However, such a method has a limit to the heat output that can be obtained due to the temperature of the heating medium and the pressure resistance of the container. For this reason, as shown in Fig. 3, JP-A No. 57-55985 discloses, in addition to MH1 and MH2 in Fig. 1, a third MH1 and MH2 whose hydrogen equilibrium decomposition pressure is higher than that of MH2 in the operating temperature range. A method of obtaining lower temperature cooling output using metal hydrides (MH3) is disclosed.

That is, MH1 is heated to high temperature TH to release hydrogen, which is absorbed into MH2 at medium temperature TM, and this
MH2 is heated to high temperature TH to release hydrogen, which is occluded by MH3 at medium temperature TM. Then,
MH1 is cooled to medium temperature, and MH3 is cooled to low temperature.
Hydrogen is released at TL', this hydrogen is occluded in MH1, and in this way, a cold output at a temperature TL' is obtained in a low-temperature heat medium that can exchange heat with MH3. Here, since the cycle ABDC is the same as the cycle in Figure 1, by constructing the cycle ABEFD′C using MH3, the temperature
It is possible to obtain the cooling output of TL' which is lower temperature than TL.

Similarly, as shown in Fig. 4, JP-A-57-179533 discloses, in addition to MH1 and MH2 in Fig. 2, a fourth metal hydride whose hydrogen equilibrium decomposition pressure is lower than that of MH1 in the operating temperature range. A method of obtaining higher temperature thermal output using (MH4) is disclosed. That is, MH2 is heated to medium temperature TM to release hydrogen, which is exothermically occluded in MH4 at high temperature TH', and then this MH4 is cooled to medium temperature TM, MH1 is kept at low temperature TL, and hydrogen is released from MH4. Release hydrogen and store it in MH1. Then, M.H.
1 is heated to medium temperature TM to release hydrogen, this hydrogen is occluded in MH2 of low temperature TL, this MH2 is heated to medium temperature TM, and the cycle of A'EFCDB is performed in this way, thereby generating MH4. The thermal output of high-temperature TH′ is obtained using an exothermic reaction. In this cycle, the cycle ACDB is the same as the cycle in FIG. 2, so by using MH4, a thermal output of TH', which is higher than TH, can be obtained.

Hereinafter, if the method shown in FIGS. 1 and 2 is referred to as the conventional method, and the method shown in FIGS. 3 and 4 is referred to as the improved method, in the conventional method, one metal hydride releases hydrogen. However, the process in which other metal hydrides absorb this, that is, the hydrogen transfer process, is
In contrast to 2 times per cycle, according to the improved method, there are 3 hydrogen transfer processes per cycle, and the time required for 1 cycle is 1.5 times, so the output per hour is reduced to 2/3. In addition, it requires three types of metal hydrides with different hydrogen equilibrium decomposition pressures in the operating temperature range, and furthermore, the amount of hydrogen transferred in each hydrogen transfer process must be equal.
Setting conditions is not always easy.

The present invention has been made in view of the above, and includes:
It is an object of the present invention to provide a method that can obtain cooling and heating at a temperature level equivalent to that of the above-mentioned improved method, while requiring the same time for one cycle as the conventional method.

The method for obtaining cold output according to the present invention includes a first working pair consisting of a first metal hydride with a low hydrogen equilibrium decomposition pressure and a second metal hydride with a high hydrogen equilibrium decomposition pressure in an operating temperature range; A second working pair consisting of a third metal hydride with a low decomposition pressure and a fourth metal hydride with a high hydrogen equilibrium decomposition pressure is provided, and in the first working pair, the first metal hydride is heated to a high temperature. The second metal hydride is heated to release hydrogen, the second metal hydride absorbs the hydrogen, and the second metal hydride is then endothermically released at low temperatures to absorb the hydrogen into the first metal at an intermediate temperature. While causing the hydride to perform a cycle of occluding hydrogen, in the second working pair, when hydrogen is released from the fourth metal hydride at a low temperature and this hydrogen is stored in the third metal hydride, the second The third metal hydride is cooled to a low temperature by an endothermic reaction of the metal hydride, and the fourth metal hydride is cooled to a low temperature.
It is characterized by obtaining cold output from the endothermic reaction of metal hydride.

Further, the thermal output acquisition method according to the present invention includes a first working pair consisting of a first metal hydride having a low hydrogen equilibrium decomposition pressure and a second metal hydride having a high hydrogen equilibrium decomposition pressure in the operating temperature range; A second working pair consisting of a third metal hydride with a low hydrogen equilibrium decomposition pressure and a fourth metal hydride with a high hydrogen equilibrium decomposition pressure is provided, and in the first working pair, the second metal hydride is heated to a medium temperature to release hydrogen, the hydrogen is exothermically occluded in a first metal hydride at a higher temperature, and then hydrogen is released from the first metal hydride and transferred to a second metal hydride at a lower temperature. At the same time, in the second working pair, hydrogen is released from the fourth metal hydride at high temperature, and when this hydrogen is stored in the third metal hydride, the above-mentioned The fourth metal hydride in the second working pair is heated by the exothermic reaction of the first metal hydride, and the thermal output is obtained from the exothermic reaction of the third metal hydride.

The method of the present invention will be explained below based on the drawings. FIG. 5 is a clockwise cycle diagram showing a method of obtaining cold output.

In this method, the first working pair consists of MH1, which has a low hydrogen equilibrium decomposition pressure, and MH2, which has a high hydrogen equilibrium decomposition pressure, in the operating temperature range, MH3, which has a low hydrogen equilibrium decomposition pressure, and MH4, which has a high hydrogen equilibrium decomposition pressure.
A second working pair consisting of is provided, and the first working pair uses a high temperature heat medium as a heat source, as in the conventional method, and
Cycle ABDC is carried out, and MH2 in the low temperature TL releases hydrogen, and MH2 in the medium temperature TM absorbs this hydrogen. Utilizing the endothermic reaction of MH2, MH3 in the second working pair is cooled to the low temperature TL. , M.H.
By endothermically releasing hydrogen from MH4 and occluding it in MH4, and thus performing the ABFE cycle, the temperature TL lower than the cold temperature TL obtained by the conventional method from MH4 of the second working pair is achieved. ′ is obtained.

Note that MH1 and MH2 in the first working pair
are preferably the same as MH3 and MH4, respectively, in the second working pair, but need not necessarily be the same, as long as the characteristics are similar.

FIG. 6 is a counterclockwise cycle diagram showing a method of obtaining thermal output.

In this method, the first working pair uses a medium-temperature heating medium as a heat source, as in the conventional method.
DCEF is performed, and by utilizing the exothermic reaction when MH2 of medium temperature TM releases hydrogen and MH1 of high temperature TH absorbs this hydrogen, the second working pair
MH4 is heated to a high temperature TH, and from this MH4 MH
MH of the second working pair by transferring hydrogen to 3 and thus performing the BAEF cycle.
3, a thermal output at a temperature TH' higher than the temperature TH obtained by the conventional method is obtained.

Although the case where two working pairs are used has been described above, it goes without saying that by using three or more working pairs, it is possible to obtain cold or hot heat at a lower or higher temperature.

As described above, according to the method of the present invention, the hydrogen transfer process is performed twice per cycle, and therefore,
Although the time required for one cycle is shorter than in the improved method, the temperature levels of the resulting cold and thermal outputs are the same as in the improved method.

For example, according to one experimental example, in the cycle diagram shown in FIG. 5, 10 kg of TiMn _1.5 was added to MH1 and MH3, and
When using 10 kg of MmNi ₅ (Mm represents Mitsushi Metal) in each case, cold heat at -5° C. can be obtained with an output of 500 Kcal/hour using a high-temperature heating medium at 60° C. On the other hand, according to the conventional method, it is possible to obtain a cooling output of only about +10° C., and in the case of the above-mentioned improved method, the output is 400 Kcal/hour.

Moreover, in the cycle diagram shown in FIG.
10Kg of LaCo ₅ to MH1 and MH3 each,
In addition, 10 kg of CaNi ₅ was added to MH2 and MH4 respectively.
160℃ using medium temperature heating medium of 80℃
of heat can be obtained with an output of 500Kcal/hour. On the other hand, according to the conventional method, it is possible to obtain a thermal output of only about 115℃, and in the case of the above improved method, the output is 400Kcal/
It's time.

[Brief explanation of drawings]

Fig. 1 is a cycle diagram for obtaining cold output by a clockwise cycle in the conventional method, Fig. 2 is a cycle diagram for obtaining thermal output in a counterclockwise cycle in the conventional method, and Figs. 3 and 4 are FIGS. 5 and 6 are cycle diagrams for obtaining cooling and heating outputs that are an improvement over the conventional method. FIGS. 5 and 6 are cycle diagrams for obtaining cooling and heating outputs according to the present invention.

Claims (1)

[Claims] 1. A first metal hydride with a low hydrogen equilibrium decomposition pressure in the operating temperature range and a second metal hydride with a high hydrogen equilibrium decomposition pressure.
a first working pair consisting of a metal hydride, and a second working pair consisting of a third metal hydride with a low hydrogen equilibrium decomposition pressure and a fourth metal hydride with a high hydrogen equilibrium decomposition pressure.
a working pair, and in the first working pair, a first working pair is provided.
heating a metal hydride to a high temperature to release hydrogen, and occluding this hydrogen in a second metal hydride;
Next, a cycle is performed in which hydrogen is endothermically released from the second metal hydride at a low temperature and absorbed into the first metal hydride at an intermediate temperature, and at the same time, in the second working pair, a fourth metal hydride is released from the second metal hydride. When hydrogen is released from the hydride at a low temperature and this hydrogen is stored in the third metal hydride, the third metal hydride is cooled to a low temperature by an endothermic reaction of the second metal hydride, and the third metal hydride is cooled to a low temperature. 4. A cold output acquisition method characterized by obtaining cold output from the endothermic reaction of metal hydride. 2 A first metal hydride with a low hydrogen equilibrium decomposition pressure in the operating temperature range and a second metal hydride with a high hydrogen equilibrium decomposition pressure.
a first working pair consisting of a metal hydride, and a second working pair consisting of a third metal hydride with a low hydrogen equilibrium decomposition pressure and a fourth metal hydride with a high hydrogen equilibrium decomposition pressure.
a working pair, and in the first working pair, a second working pair is provided.
metal hydride is heated to moderate temperature to release hydrogen, the hydrogen is exothermically occluded in the hot first metal hydride, and then hydrogen is released from the first metal hydride to release hydrogen. A cycle of storing hydrogen in the second metal hydride at a low temperature is performed, and in the second working pair, hydrogen is released from the fourth metal hydride at a high temperature, and this hydrogen is stored in the third metal hydride. In particular, the fourth metal hydride in the second working pair is heated by the exothermic reaction of the first metal hydride to obtain thermal output from the exothermic reaction of the third metal hydride. How to obtain thermal output.