JPH0120347B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method of operating a heat pump device,
More specifically, the present invention relates to a method of operating a heat pump device using metal hydrides.

It is known that certain metals and alloys rapidly and exothermically absorb hydrogen to form metal hydrides, and that these metal hydrides reversibly and endothermically release hydrogen. The equilibrium decomposition pressure P of such a metal hydride is generally a function of temperature, and as shown in FIG. 1, the higher the temperature T, the greater the equilibrium decomposition pressure. Therefore, for example, if a metal hydride is built into two heat exchangers connected so that hydrogen can flow between them, and one is kept at a high temperature T _H and the other at a low temperature T _L , the heat exchange on the high temperature side is The metal hydride in the vessel emits hydrogen endothermically at the equilibrium decomposition pressure P _H.
Since the equilibrium decomposition pressure of the metal hydride in the heat exchanger on the low temperature side is P _L (<P _H ), the above hydrogen moves to the heat exchanger on the low temperature side due to this difference in equilibrium decomposition pressure, and this The metal hydride in the heat exchanger absorbs hydrogen exothermically. That is, heat is transported from the heat exchanger on the high temperature side to the heat exchanger on the low temperature side.

In addition, if the two heat exchangers mentioned above are connected so that hydrogen flows through a compressor, and one heat exchanger is depressurized while the other heat exchanger is pressurized with hydrogen, the metal hydride on the depressurized side can be Hydrogen is released endothermically, and the metal hydride on the pressurized side absorbs hydrogen exothermically. That is, heat is transported from the reduced pressure side to the increased pressure side. Therefore, for example, if the pressure reduction side is set to a lower temperature T _L
The pressure side is connected to a cooling load of high temperature T _H (＞
When connected to T _L ), heat is transported from the low temperature side to the high temperature side, so it functions as a heat pump.

However, in any of the above heat transport devices or heat pump devices, heat transport stops when all the hydrogen is released from one metal hydride, so in order to continue heat transport, in the former device two Two heat exchangers must be alternately heated and cooled, and in the latter device two heat exchangers must be alternately pressurized and depressurized. That is, since heat transport is essentially a batch method, when the heat generated or absorbed by the metal hydride is extracted as output, the output is not stationary. If four or more heat exchangers are used, a phase difference is created between each heat exchanger, hydrogen is released and absorbed, and the output is taken out from each heat exchanger sequentially, it appears to be continuous. However, it requires a complicated control mechanism. Furthermore, in conventional devices, the calorific value or endothermic value of the metal hydride is consumed for heating or cooling the heat exchanger itself, or extra thermal energy is required.
They cannot avoid various disadvantages. Furthermore, since metal hydrides generally have low thermal conductivity, a tube group with fins is often used as a heat exchanger, and as a result, the heat exchanger itself has a large heat capacity and poor heat transport efficiency.

The present invention was made in order to solve the various problems described above in conventional heat pump devices, and is a heat pump that eliminates the need for heating and cooling cycles of a heat exchanger and can continuously extract stable output. The purpose is to provide instructions on how to operate the device.

A method for operating a heat pump device suitable for use as a heating device according to the present invention includes a high-pressure chamber, an intermediate-pressure chamber, and a low-pressure chamber defined by partition walls in a closed container, a first metal hydride supported thereon, and a rotating belt. A first tape is run between a high pressure chamber and an intermediate pressure chamber in a rotating belt shape, and a second metal hydride whose equilibrium decomposition pressure characteristics are in a higher temperature range than that of the first metal hydride is supported. a second tape running between the intermediate pressure chamber and the low pressure chamber, a medium temperature heating medium thermally connected to the first tape in the high pressure chamber so as to be able to exchange heat with the first tape, and a second tape running in the low pressure chamber. A low-temperature heating medium is thermally connected to the tape so as to be able to exchange heat with the third metal hydride, and a third metal hydride whose equilibrium decomposition pressure characteristics are in a higher temperature range than the second metal hydride is supported. a third tape running between the high pressure chamber and the low pressure chamber;
It has a high-temperature heating medium and a medium-temperature heating medium that are thermally connected to the third tape in the high-pressure chamber and the third tape in the low-pressure chamber so as to be able to exchange heat, respectively, and the second tape absorbs hydrogen in the low-pressure chamber, and the third tape in the low-pressure chamber absorbs hydrogen. In the pressure chamber, the second tape is heated to release hydrogen, and the first tape is cooled to absorb this hydrogen, and in the high pressure chamber, hydrogen is released from the first tape while the third tape generates heat. Hydrogen is absorbed by the third tape in a low-pressure chamber, and hydrogen is absorbed by the second tape to transport heat from the medium-temperature heat medium to the high-temperature heat medium. Another method of operating a heat pump device suitable as a cooling device according to the present invention includes a high-pressure chamber, an intermediate-pressure chamber, and a low-pressure chamber defined by partition walls in a closed container, and supporting a first metal hydride; A first tape is run between a low pressure chamber and an intermediate pressure chamber in the form of a rotating belt, and a second metal hydride whose equilibrium decomposition pressure characteristics are in a lower temperature range than that of the first metal hydride is supported, and the tape is rotated. A second tape running in the form of a belt between the intermediate pressure chamber and the high pressure chamber, an intermediate temperature heating medium thermally connected to the first tape in the low pressure chamber so as to be able to exchange heat, and a medium temperature heating medium in the high pressure chamber. A rotating belt carries a high temperature heating medium thermally connected to the second tape so as to be able to exchange heat with the second tape, and a third metal hydride whose equilibrium decomposition pressure characteristics are in a lower temperature range than that of the second metal hydride. a third tape running between the low pressure chamber and the high pressure chamber in a manner similar to that;
It has a low-temperature heating medium and a medium-temperature heating medium that are thermally connected to the third tape in the low-pressure chamber and the third tape in the high-pressure chamber, respectively, so as to be able to exchange heat, and the first tape absorbs hydrogen in the low-pressure chamber, and In the pressure chamber, the first tape is heated to release hydrogen and the second tape is cooled to absorb this hydrogen, and in the high pressure chamber, hydrogen is released from the second tape and a third tape is heated Hydrogen is absorbed into the third tape in a low-pressure chamber, and hydrogen is absorbed endothermically from the third tape, and hydrogen is absorbed into the first tape to transport heat from the low-temperature heat medium to the medium-temperature heat medium. .

The present invention will be explained below with reference to drawings showing examples.

FIG. 2 shows a basic embodiment of a heat pump device suitably used for heating in the present invention. The sealed container 1 is divided by a partition wall 2 into a high pressure chamber 3, an intermediate pressure chamber 4, and a low pressure chamber 5. Medium temperature roll 6 placed in the high pressure room and low temperature roll 7 placed in the medium pressure room
A first tape in the form of a rotating belt carrying a first metal hydride M ₁ H is wound between the partition wall and the partition wall while substantially maintaining airtightness by an appropriate sealing means provided on the partition wall. It penetrates through and is driven to travel in a fixed direction. The medium-temperature roll is thermally connected to the medium-temperature heating medium 8, and the low-temperature roll is thermally connected to the low-temperature heating medium 9 so as to be able to exchange heat. Further, as shown in FIG. 3, a second tape supporting a second metal hydride M ₂ H whose equilibrium decomposition pressure characteristics are in a higher temperature range than M ₁ H is placed on a low temperature roll 10 arranged in a low pressure chamber.
It is wound between the medium temperature roll 11 arranged in the medium pressure chamber and the medium temperature roll 11 disposed in the medium pressure chamber, penetrates the partition wall in the same manner as described above, is connected between the low pressure chamber and the medium pressure chamber, and travels back and forth. The low-temperature roll 10 is connected to the low-temperature heating medium 9, and the medium-temperature roll 11 is connected to the medium-temperature heating medium 8 so as to be able to exchange heat. That is, an intermediate pressure chamber is provided between the high pressure chamber and the low pressure chamber, and metal hydrides having different equilibrium decomposition pressure characteristics are arranged in this intermediate pressure chamber so as to be supported at different temperatures.

Furthermore, between the high temperature roll 12 placed in the high pressure chamber and the medium temperature roll 13 placed in the low pressure chamber, a third metal hydrogen whose equilibrium decomposition pressure characteristics are in a higher temperature range than M ₂ H is placed between the high temperature roll 12 placed in the high pressure chamber and the medium temperature roll 13 placed in the low pressure chamber. A third tape carrying the compound M ₃ H is driven to run, the high temperature roll 12 is connected to the high temperature heating medium 14, and the medium temperature roll 13 is connected to the medium temperature heating medium 15.
They are each thermally connected to allow heat exchange. Here, the temperature relationship of the heating medium is T _L < T _M <
T _H.

The operation of this device will be explained based on the cycle diagram shown in FIG. First, in the low-pressure chamber, M ₂ H is cooled by the low-temperature heat medium 9 at a temperature T _L , absorbs hydrogen in the state at point A, and is heated to a temperature T _M by the medium-temperature heat medium 8 in the medium-pressure chamber. At point B, hydrogen is released endothermically. This hydrogen is stored at point C in M ₁ H, which is cooled to temperature T _L by low-temperature heating medium 9, and M ₁ H is heated to temperature T _M in the high-pressure chamber, and at point D, high-pressure hydrogen is stored. emit. That is, hydrogen stored at low pressure in the low pressure chamber is exchanged between two metal hydrides in the medium pressure chamber, and released as high pressure hydrogen in the high pressure chamber.

This hydrogen released from M ₁ H is stored at point E in a high-pressure chamber at a temperature T _H selected so as to have an equilibrium decomposition pressure slightly lower than the equilibrium decomposition pressure of M ₁ H.
It is occluded by M ₃ H. The exothermic reaction heat at this time is output to the high temperature heat medium 14. The hydrogen-absorbed M ₃ H is heated and maintained at a temperature T _M by a medium-temperature heating medium in the low-pressure chamber, and endothermically releases hydrogen at point F. This hydrogen is occluded at point A of M ₂ H at temperature T _L. That is, in this device, heat is transported from a medium-temperature heat medium to a high-temperature heat medium.

As described above, according to the method of operating a heat pump device of the present invention, a third metal hydride is supported on a rotating belt-like tape, and the third metal hydride is continuously moved back and forth between a high-pressure chamber and a low-pressure chamber at different temperatures. This essentially continuous operation provides a continuous and stable heat output. For this reason, unlike conventional equipment using a heat exchanger filled with metal hydride, which requires switching the heat source to alternately heat and cool the heat exchanger, the heat source or heat medium is always kept at a constant temperature. Therefore, there is no need for a complicated heat medium circuit or a control device therefor, and the device configuration is significantly simplified.

Furthermore, according to the present invention, an intermediate pressure chamber is interposed between the high pressure chamber and the low pressure chamber in order to supply and absorb high pressure hydrogen to the third tape and to release hydrogen from the third tape. Since hydrogen is exchanged between the first and second metal hydrides having different equilibrium decomposition pressure characteristics in this medium pressure chamber, low pressure hydrogen can be increased to high pressure by utilizing a small temperature difference. .

The above device uses a high-temperature heat medium as an indoor heating load,
By using solar heat, boiler heat, various waste heat sources, etc. as the medium-temperature heat medium, and using the low-temperature heat medium as a cooler for atmospheric temperature or water temperature, it can function as a heating device.

In addition, in the above, for simplicity, all temperatures of the low-temperature heat medium are T _L and all temperatures of the medium-temperature heat medium are T _M
However, it is fair to say that there is no problem even if these are different.

Next, in the present invention, a plurality of intermediate pressure chambers may be provided in series. Generally, as shown in FIG. 4, when a number n of medium pressure chambers C ₁ , C ₂ , ..., _Co are provided in order from the high pressure chamber 3 to the low pressure chamber 5,
Metal hydride between _M1H tape and _M2H tape
_The number _{( n-}
The intermediate tape of 1) is run like a rotating belt between adjacent medium pressure chambers. Here, each metal hydride has an equilibrium decomposition pressure characteristic of M ₁ H, A ₁ ,..., A _i ,...,
A _o-1 , M ₂ H are selected in the order of high temperature range,
In the i-th medium pressure chamber C _i counting from the high pressure chamber, the A _i tape is kept at a higher temperature and the A _i-1 tape is kept at a lower temperature, and hydrogen is exchanged between the tapes. In addition, in order to reduce the number of types of heating medium, all A _i tapes in intermediate chamber C _i should be
It is sufficient to thermally connect all of the A _i-1 tapes to the medium-temperature heating medium of T _M and to the low-temperature heating medium of temperature T _L. In this way, the number of zigzag stages of hydrogen pressurization from A to D through B and C in FIG. 3 increases,
Higher pressure hydrogen can be obtained from metal hydrides M ₁ H.

Furthermore, in the present invention, tapes supporting the third metal hydride M ₃ H may be arranged in multiple stages in parallel with each other. Generally, as shown in Figure 4, several meters of tape supporting metal hydrides B ₁ , B ₂ , ..., B _n , each with different equilibrium decomposition pressure characteristics, are continuously connected to a high-pressure chamber in parallel. The i-th tape is moved back and forth in the low pressure chamber at a temperature T _Mi
It is thermally controlled to have a medium temperature of T Hi and a high temperature of T _Hi in the high pressure chamber. Here, the temperature relationships are T _Mi <T _Mi+1 , T _Hi <T _Hi+1 , and T _Mi <T _Hi , and the decomposition equilibrium pressure characteristics of each metal hydride are as follows:
B _i+1 is chosen so that it is in a higher temperature region than B _i .
For simplicity and efficient use of thermal energy, in the illustrated embodiment the first tape is connected to a medium temperature heating medium at a temperature T _M1 in a low pressure chamber, and the mth tape is connected to a medium temperature heating medium at a temperature T _Hn in a high pressure chamber. In addition to connecting to the high temperature heating medium of
The i-th (1im-1) tape in the high-pressure chamber and the (i+1)-th (1i) tape in the low-pressure chamber.
The tape support roll is thermally connected to the tape m-1) by appropriate means such as a heat pipe so that the tape can exchange heat with the tape.

The operation in this case will be explained using the cycle diagram shown in FIG. However, for the sake of simplicity, it is assumed that there is only one medium pressure chamber, and that the third tape has _B1 and _B2 tapes arranged in two stages. As mentioned above,
M ₂ H absorbs hydrogen in a low pressure chamber at a temperature T _L , and M ₁ H releases this hydrogen in a high pressure chamber at a temperature T _M. This hydrogen is exothermically occluded by B ₁ and B ₂ at temperatures T _H1 and T _H2 , respectively (points E and G). At this time, B ₁
The heat generated by B2 is transmitted to _B2 in the low-pressure chamber by a heat pipe, etc., and the heat generated by _B2 is given to the high-temperature heating medium.
B ₁ and B ₂ then enter the low pressure chamber, each at a temperature of
While being heated and maintained at T _M1 (=T _M ) and T _M2 (=T _H1 ), hydrogen is released endothermically (points F and H). This hydrogen is occluded by M ₂ H at temperature T _L (point A).

According to this device, by using M ₁ H and M 2 H arranged in series through an intermediate pressure chamber, high pressure hydrogen can be obtained by utilizing a small temperature difference, and by using M 1 H and M ₂ H arranged in parallel. A higher temperature output can be obtained from the third tape. When used as a heating device, a high temperature heat medium may be used as the heating load, solar heat, various waste heat, etc. may be used as a medium temperature heat medium as a heat source, and an air cooler or the like may be used as a low temperature heat medium.

Next, FIG. 6 shows an embodiment of a heat pump device suitable for use as a cooling device according to the present invention. As in the case of the heating device, the sealed container 1 has a high pressure chamber 3, an intermediate pressure chamber 4, and a low pressure chamber 5 which are defined by a partition wall 2, and a medium temperature roll 16 arranged in the low pressure chamber.
A first tape in the form of a rotating belt carrying the first metal hydride M ₁ H is continuously reciprocated through the partition wall between the high temperature rolls 17 arranged in the intermediate pressure chamber. The medium-temperature roll 16 is connected to a medium-temperature heating medium 18, and the high-temperature roll is connected to a high-temperature heating medium 19 for heat exchange. In addition, as shown in FIG. 7, a second tape supporting a second metal hydride M ₂ H whose equilibrium decomposition pressure characteristics are in a lower temperature range than M ₁ H is placed between a medium temperature roll 20 placed in a medium pressure chamber and a high pressure It is continuously run between it and a high temperature roll 21 arranged in the chamber. This medium temperature roll 2
0 is thermally connected to the medium-temperature heating medium 18, and the high-temperature roll 21 is thermally connected to the high-temperature heating medium 21 so as to be able to exchange heat.

Further, a third tape is run between the low temperature roll 22 placed in the high pressure chamber and the medium temperature roll placed in the high pressure chamber. In the illustrated embodiment, a third tape carrying metal hydrides D ₁ and D ₂ is run in parallel. Here, the _D1 tape is supported by a low temperature roll 22 at a temperature T _L1 in a low pressure chamber, and is supported by a medium temperature roll 22 at a temperature T _M in a high pressure chamber.
3, and this medium temperature roll has a temperature T _M
It is connected to the intermediate temperature heating medium 24 of. In parallel to the D ₁ tape, a tape supporting a metal hydride D ₂ whose equilibrium decomposition pressure characteristics are in a lower temperature range than D ₁ is placed between a low temperature roll 25 placed in a low pressure chamber and a medium temperature roll 26 placed in a high pressure chamber. The low-temperature roll 22 and the medium-temperature roll 26 run continuously, preferably the heat pipe 2
7, etc., so as to be able to exchange heat and are maintained at a temperature T _L1 , and the low temperature roll 25 is connected to a low temperature heating medium 28 at a temperature T _L2 . Here, the temperature relationship is T _L2 < T _L1 < T _M < T _H.

The operation of this device will be explained based on the cycle diagram shown in FIG. First, in the low-pressure chamber, M ₁ H exothermically absorbs hydrogen at a temperature T _M (point A), and the heat of exothermic reaction at this time is removed by the medium-temperature heating medium 18 serving as a cooler. The hydrogen-absorbed M ₁ H tape is heated to a temperature T _H in a medium pressure chamber to release hydrogen (point B), and this hydrogen is exothermically absorbed into the M ₂ H tape at a temperature T _M (point C). ). M ₂ H is heated in the high pressure chamber to a temperature T _H by the high temperature heating medium 19, and releases high pressure hydrogen (point D).

The hydrogen released by M ₂ H in the hyperbaric chamber is exothermically occluded in the D ₁ and D ₂ tapes at temperatures T _M and T _L1 , respectively (points E and F). D ₁ and D ₂ that have stored hydrogen endothermically release hydrogen in the low pressure chamber. At this time, the heating of the _D1 tape by the low temperature roll 22 is provided by a heat pipe 27 etc. from the low temperature roll 26,
The D ₂ tape is heated by receiving heat from a low temperature heat source 28 at a temperature T _L1 . Therefore, if a heat source such as solar heat, boiler heat, or various types of waste heat is used as the high-temperature heat medium 19, and an air cooler or the like is used as the medium-temperature heat source 18, 24, the cold output can be reduced from the low-temperature heat medium 28 as the cooling load. can be obtained.

Furthermore, as described above regarding a heat pump device suitable for a heating device, a device suitable for this cooling device may also be provided with a plurality of medium pressure chambers or may have a plurality of third tapes arranged in parallel. The operation will be easily understood from the above explanation.

[Brief explanation of drawings]

Fig. 1 is a graph showing general equilibrium decomposition pressure characteristics of metal hydrides, Fig. 2 is a schematic diagram showing an embodiment of a heat pump device suitably used for heating in the present invention, and Fig. 3 is a graph showing general equilibrium decomposition pressure characteristics of metal hydrides. FIG. 2 is a cycle diagram showing the operation of the device, FIG. 4 is a schematic diagram showing another embodiment, FIG. 5 is a cycle diagram showing an example of the operation of the device in FIG. FIG. 7 is a schematic diagram showing a heat pump device suitably used for cooling in the present invention, and FIG. 7 is a cycle diagram showing the operation of the device shown in FIG. 6. 1... Sealed container, 2... Partition wall, 3... High pressure chamber,
4... Medium pressure chamber, 5... Low pressure chamber, 8... Medium temperature heating medium,
9...Low temperature heat medium, 14...High temperature heat medium, 15...Medium temperature heat medium, 18...Medium temperature heat medium, 19...High temperature heat medium,
24... Medium temperature heating medium, 28... Low temperature heating medium, M ₁ H...
...first metal hydride, _M2H ...second metal hydride, _M3H ...third metal hydride.

Claims (1)

[Scope of Claims] 1. A high pressure chamber, an intermediate pressure chamber, and a low pressure chamber that are defined by partition walls in a closed container, and a first metal hydride is supported, and the high pressure chamber and the intermediate pressure chamber are arranged in a rotating belt shape. A first tape is run between a medium-pressure chamber and a low-pressure chamber in the form of a rotating belt, carrying a second metal hydride whose equilibrium decomposition pressure characteristics are in a higher temperature range than that of the first metal hydride. A second tape running between the tape, a medium-temperature heating medium thermally connected to be able to exchange heat with the first tape in the high-pressure chamber, and a second tape in the low-pressure chamber so as to be able to exchange heat. supporting a thermally connected low-temperature heating medium and a third metal hydride whose equilibrium decomposition pressure characteristics are in a higher temperature range than the second metal hydride;
A third tape that runs between the high pressure chamber and the low pressure chamber in the form of a rotating belt, and a high temperature heating medium that is thermally connected to the third tape in the high pressure chamber and the low pressure chamber so as to be able to exchange heat, respectively. A second tape absorbs hydrogen in a low-pressure chamber, and the second tape is heated in a medium-pressure chamber to release hydrogen, and the first tape is cooled to absorb hydrogen. hydrogen is released from the first tape and exothermically occluded by the third tape in the high pressure chamber, and hydrogen is endothermically released from the third tape and occluded by the second tape in the low pressure chamber. A method of operating a heat pump device, characterized in that heat is transported from a medium-temperature heat medium to a high-temperature heat medium. 2. A high-pressure chamber, an intermediate-pressure chamber, and a low-pressure chamber that are divided by partition walls in a closed container, and a second chamber that carries a first metal hydride and runs between the low-pressure chamber and the intermediate-pressure chamber in the form of a rotating belt. The second tape carries a first tape and a second metal hydride whose equilibrium decomposition pressure characteristics are in a lower temperature range than the first metal hydride, and is run between a medium pressure chamber and a high pressure chamber in the form of a rotating belt. tape, a medium-temperature heating medium thermally connected to exchange heat with the first tape in the low-pressure chamber, and a high-temperature heating medium thermally connected to exchange heat with the second tape in the high-pressure chamber. A third tape carrying a heating medium and a third metal hydride whose equilibrium decomposition pressure characteristics are in a lower temperature range than that of the second metal hydride, and is run between the low pressure chamber and the high pressure chamber in a rotating belt shape. and a low-temperature heating medium and a medium-temperature heating medium that are thermally connected to the third tape in the low-pressure chamber and the third tape in the high-pressure chamber so as to be able to exchange heat, respectively, and the first tape absorbs hydrogen in the low-pressure chamber. In a medium pressure chamber, the first tape is heated to release hydrogen and the second tape is cooled to absorb the hydrogen, and in a high pressure chamber, hydrogen is released from the second tape and transferred to the third tape. exothermically occluded,
A method for operating a heat pump device, characterized in that hydrogen is endothermically released from a third tape in a low-pressure chamber, and hydrogen is stored in the first tape to transport heat from a low-temperature heat medium to a medium-temperature heat medium.