JPS6327623B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to metal hydride devices.

It is known that certain metal alloys absorb hydrogen exothermically to form metal hydrides, and that these metal hydrides reversibly release hydrogen.
In recent years, various metal hydride devices such as heat pumps that utilize the characteristics of metal hydrides have been proposed. Conventionally, a first metal hydride MH1 and a second metal hydride having different equilibrium decomposition pressures are used.
In the case of a so-called four-cylinder metal hydride device, MH2 is filled in a closed container that can exchange heat with a heating medium, and the containers are communicated so that hydrogen can move between them to form a working pair. constitutes a metal hydride device by providing two pairs of the above working pairs.

The operation of such a metal hydride device will be explained based on the cycle diagram shown in FIG. 1, with respect to the case where the cooling output is obtained through a so-called clockwise cycle.

In the drawing, the horizontal axis shows the reciprocal of absolute temperature,
The vertical axis shows the logarithm of the equilibrium decomposition pressure of the metal hydride.
Initially, it is assumed that MH1 is in a state in which it has sufficiently absorbed hydrogen (point D), and MH2 is in a state in which it has sufficiently released hydrogen (point C). First, MH1, which has a high equilibrium decomposition pressure in the operating temperature range, is heated by a high-temperature driven heat source at temperature TH, and MH1, which has a low equilibrium decomposition pressure,
When 2 is connected to a medium-temperature heating medium of temperature TM, such as outside air, MH1 endothermically releases hydrogen (point A), and MH2 absorbs this hydrogen exothermically (B).
After the hydrogen transfer is completed, MH1 is switched to a medium-temperature heating medium and connected, and MH2 is switched to and connected to a low-temperature heating medium of temperature TL for cooling loads, such as chilled water, and MH2 endothermically releases hydrogen. (Point C), and MH1 exothermically occludes this hydrogen (Point D). Here, cold output can be obtained from the low-temperature heat medium (point C), and if necessary, the medium-temperature heat medium (point B) can be obtained.
and D) thermal output can be obtained. Once again, connect MH1 to the high temperature driving heat source and connect MH2 to the medium temperature heat transfer medium to start a new cycle.

Therefore, by causing another working pair to perform the same cycle as above with a half-cycle delay, the cooling output associated with hydrogen release from MH2 can be obtained alternately from each working pair, and can be used, for example, for cooling. Also,
Thermal output can be used, for example, for space heating or hot water supply.

However, in conventional metal hydride equipment that uses multiple pairs of the same working pairs consisting of two types of metal hydrides with different equilibrium decomposition pressures,
Since the temperature of the driving heat source is fixed in advance depending on the type of MH1 and MH2, for example, an expensive heat source such as city gas and a cheap or free heat source such as solar heat or waste heat, 2 different temperatures
Even if two or more heat sources can be used, it is necessary to use only one of the heat sources as the drive heat source depending on the preset operating temperature, and in particular, a low-cost or free heat source is used as the second heat source. If it cannot be used as a device, the coefficient of performance of the device is low;
It has poor thermoeconomic efficiency.

The present invention was made in order to solve such problems, and it is possible to efficiently utilize a plurality of heat sources at different temperatures as driving heat sources at the same time, and therefore,
The object of the present invention is to provide a metal hydride device that is highly economical in using a heat source and has a high coefficient of performance.

The first metal hydride device according to the present invention uses three types of metal hydrides that have different equilibrium decomposition pressures in the operating temperature range, and has two sealed containers filled with two types of metal hydrides that have different equilibrium decomposition pressures. They communicate with each other to form a working pair so that hydrogen can move, and at least two working pairs are provided, the first having a lower equilibrium decomposition pressure.
A metal hydride is filled into one sealed container of the first working pair, and a second metal hydride, which has the next lowest equilibrium decomposition pressure, is filled into one sealed container of the second working pair, and the equilibrium decomposition pressure is It is characterized in that the remaining closed containers of the first and second working pairs are filled with a third metal hydride having a large hydride.

EMBODIMENT OF THE INVENTION The 1st metal hydride apparatus of this invention is demonstrated based on the drawing which shows an Example below.

Figure 2 shows three types of metal hydrides, MH1, MH2, and
An example of the first metal hydride device using MH3 is shown, with MH1 having the lowest equilibrium decomposition pressure and the next lowest equilibrium decomposition pressure.
The sealed containers 1 and 3 forming a heat exchanger are filled with MH2, respectively, and MH2 with a high equilibrium decomposition pressure is
3 is filled in closed containers 2 and 4 forming a heat exchanger, and the containers 1 and 2 are connected to a communication pipe 9 so that hydrogen can be transferred, forming a first working pair. 3 and 4 are also communicated through the communication pipe 10 to form a second working pair. Each communication pipe is provided with control valves 11 and 12 such as electromagnetic valves, and each communication pipe is opened and closed according to a cycle described later.

Further, the container 1 is a first driving heat source 5 with a high temperature TH1.
and the temperature TM are connected to a medium-temperature heating medium 6 through pipes 13 and 14, respectively, in a heat exchangeable and switchable manner, and the container 3 is connected to a medium-temperature heating medium 6 with a temperature TM, which is different from the first driving heat source.
It is connected to the second drive heat source 7 of TH2 (<TH1) and the intermediate temperature heat medium 6 through pipes 15 and 16, respectively, so that heat exchange and switching is possible. On the other hand, the first
In the working pair, the container 2 filled with MH3 having a high equilibrium decomposition pressure is connected via pipes 17 and 18 to a low-temperature heat medium 8 and a medium-temperature heat medium 6, respectively, at a temperature TL in a heat exchangeable and switchable manner. In the second working pair, the container 4 filled with MH3 is also connected via lines 19 and 20 to the low-temperature heating medium 8 and the medium-temperature heating medium 6, respectively, in a heat exchangeable and switchable manner.

The connection between each container and the heat source or heating medium is switched by a control valve such as a solenoid valve (not shown). The device is a four-cylinder device with two working pairs.

The operation of the above device will be explained with reference to the cycle diagram shown in FIG. In addition, in FIG. 2, a single medium-temperature heating medium 6 is shown, and the containers 1, 2, 3, and 4 are all connected to this single medium-temperature heating medium,
The intermediate temperature heating medium does not need to be single; for example, the first
In the working pair, vessel 1 is connected to a medium temperature heating medium at temperature TM1 and vessel 2 is connected to a temperature TM2 different from TM1.
In the second working pair, vessels 3 and 4 may both be connected to a medium temperature heat medium at a temperature TM2. FIG. 3 shows a cycle diagram in which each vessel is thus connected to a respective medium temperature heating medium.

First, in the first working pair, vessel 1 is connected to a first high-temperature driving heat source to heat MH1 to temperature TH1, and vessel 2 is connected to a medium-temperature heating medium to heat MH3 to temperature TH1.
When maintained at TM2, MH1 endothermically releases hydrogen (point A), this hydrogen reaches vessel 2 via communication pipe 9, and MH3 absorbs it exothermically (point B).
At the same time, in the second working pair, the container 3 is
TM2 is connected to a medium-temperature heating medium, and the container 4 is connected to a low-temperature heating medium at a temperature TL, and hydrogen is endothermically released from MH3 (point C), which reaches the container 3 through the communication pipe 10. If the temperature is increased and MH2 is exothermically occluded (point H), cold output can be obtained in the low temperature heat medium (point C). This cold output can be used for cooling, for example. Further, the thermal output due to hydrogen storage in MH3 (point B) and the thermal output due to hydrogen storage in MH2 (point H) can be used, for example, for hot water supply, as needed.

Then, after the hydrogen transfer is completed in each working pair, in the first working pair, the vessel 1 is heated to a temperature TM1.
When connected to a medium-temperature heating medium and connecting container 2 to a low-temperature heating medium, MH3 releases hydrogen endothermically (point C) due to the pressure difference between the equilibrium decomposition pressures of MH1 and MH3 in the container. MH1 absorbs hydrogen exothermically (point D). Therefore, cold output can be obtained in the low-temperature heating medium (point C) due to heat absorption due to hydrogen release in MH3, and thermal output can be obtained in the medium-temperature heating medium (point D) due to heat generation due to hydrogen absorption in MH1. Obtainable. The cold output can be used, for example, for cooling, and the thermal output can be used, for example, for heating or hot water supply.

At the same time, in the second working pair, the container 3 is
When MH2 is heated to temperature TH2 by connecting it to a high-temperature driving heat source of MH3 is exothermically occluded (point B). If the heat generated by the hydrogen absorption of MH3 is also required, it can be obtained as thermal output in the intermediate temperature heating medium (point B).

The clockwise cycle is thus completed and a new cycle begins again by connecting each vessel to its original heat source or medium.

As described above, according to the first metal hydride device of the present invention, cold output and/or thermal output can be obtained by using two types of high-temperature heat sources having different temperatures as described above.

In addition, in the present invention, hydrogen transfer from MH1 to MH3 (A → B) is completed in the first working pair, and hydrogen transfer from MH3 to MH2 (C → H) is completed in the second working pair. When, temperature TH
Heat exchange is performed by circulating an appropriate heating medium between MH1 at temperature TM2 and MH2 at temperature TM2 through pipe 21,
Preheating MH2 to around the intermediate temperature between TH1 and TM2 is thermoeconomically advantageous because the heat supply from the drive heat source for heating MH2 to temperature TH2 in the next step can be reduced. At the same time, MH1
Since it is also possible to pre-cool the air, the efficiency of acquiring cold output is also increased. Similarly, for metal hydrides with high equilibrium decomposition pressure, MH3 at temperature TM2 and MH3 at temperature TL
It is thermoeconomically advantageous to circulate an appropriate heat medium between the MH3 and the MH3 through the pipe line 22 to perform heat exchange, and to preheat or precool each MH3 in preparation for the next step.

Also, in the first working pair, from MH3 to MH
The hydrogen transfer from MH2 to MH3 (E→D) is completed in the second working pair (C→D).
When B) is completed, heat is exchanged between MH2 at temperature TH2 and MH1 at temperature TM1, and
It is advantageous to preheat or precool the respective metal hydride by exchanging heat between MH3 at temperature TM2 and MH3 at temperature TL.

In the device temperature cycle explained above,
LaNi _4.75 Al _0.25 as MH1, as MH2
When using LaNi _4.85 Al _0.15 or LaNi _5.4 as MH3, the temperatures of the heat source and heat medium can be set approximately as follows.

Input TH1 = 100℃ (1st high temperature drive heat source) TH2 = 80℃ (2nd high temperature drive 12 heat source) Output TL1 = 10℃ (cold output) TM1 = 45℃ (thermal output) TM2 = 30℃ ( (atmospheric temperature) Therefore, it is possible to obtain a cooling output of about 10°C and a thermal output of about 45°C, and it can be suitably used in an air conditioning hot water supply system.

Next, the case where the device of the present invention is used for heating and hot water supply will be explained with reference to the cycle diagram shown in FIG.
The main parts of the device are the same as in Fig. 2, but in addition to the high-temperature drive heat source at temperature TH (reference number 7 is the same as reference number 5), there are also solar heat at temperature TL2 and temperature TL1. (<TL2), for example, two different types of low-temperature heat sources are used, including the atmosphere.
Therefore, in this apparatus for heating and hot water supply, the reference number 8 in FIG. 2 means two types of low-temperature heat sources.

In this device, MH with low equilibrium decomposition pressure
1 and MH3, which has a large equilibrium decomposition pressure, constitute the first working pair, and MH2, which has the next lowest equilibrium decomposition pressure, and MH3, which has a large equilibrium decomposition pressure, constitute the second working pair. are the same and therefore the first actuation pair constitutes a cycle of points A→B→C→D;
The second actuation pair constitutes a cycle of points E→F→G→H. According to this cycle, in the first working pair, MH1 is heated by a high temperature heat source at temperature TH, hydrogen transfer from MH1 to MH3 occurs;
The heat generated at this time (point B) can be obtained as thermal output for heating and hot water supply. MH3, which has absorbed hydrogen in this way, is then connected to a low-temperature heating medium at a temperature of TL1, while MH1, which has released hydrogen, has a temperature of TM
1, where from MH3
Hydrogen transfer to MH1 occurs, and the thermal output (point D) due to hydrogen storage in MH1 can be used for heating and hot water supply.

In the second working pair, MH2 is similarly heated by a high temperature heat source at temperature TH, resulting in hydrogen transfer from MH2 to MH3, resulting in MH3
From this, a thermal output (point F) that can be used for heating and hot water supply can be obtained. The hydrogen-absorbed MH3 is then heated by a low-temperature heat source, e.g. solar heat, at a temperature TL2, while the hydrogen-released MH2 is heated at a temperature TM1.
Cooled by a medium temperature heat source, MH3 to MH2
Hydrogen transfer occurs, and here the thermal output (point H) obtained by hydrogen storage of MH2 can be provided for heating and hot water supply.

In the above device, the same La-Ni as mentioned above is used.
When using a combination of metal hydrides, the temperatures of the heat source and heat medium can be set approximately as follows.

Input TH1 = 110℃ (high temperature heat source) TL2 = 30℃ (solar heat) TL1 = 0℃ (atmosphere) Output TM1 = 50℃ (heating and hot water supply) TM2 = 40℃ (hot water supply) Note that the cycle line in Figure 4 above In the device that operates according to the diagram, two types of low-temperature heat sources with different temperatures are used, and one of the actuating bodies is activated by one of them, making it possible to effectively utilize inexpensive thermal energy such as solar heat. It is thermoeconomically advantageous because heat can be pumped up from the atmosphere, for example.

In the conventional device, if solar heat cannot be used, hydrogen transfer from G to H becomes impossible, but with the device of the present invention, the temperature TM2 from point B, which is inferior in terms of thermal output, is Temperature at point G
By giving MH3 at , hydrogen transfer from G to H can be performed.

Next, the case of driving a counterclockwise cycle using the first metal hydride device of the present invention will be explained with reference to the cycle diagram shown in FIG. The first working pair consisting of MH1 and MH3 cycles from point A→B→C→D, the first at temperature TM1 and the second at temperature TM2.
It is driven by a medium-temperature heating medium of , giving a thermal output (point A) of temperature TH. On the other hand, the second working pair consisting of MH2 and MH3 performs a cycle from point E→F→C→H, is driven by the first intermediate temperature heating medium at temperature TM1 and the second intermediate temperature heating medium at temperature TM2, and has a thermal output at temperature TH. (Point E) is given.

This counterclockwise cycle uses, for example, two low-quality, medium-temperature driven heat sources to provide high-temperature thermal output to point A.
and can be obtained from point E.

Note that in the counterclockwise cycle, it is also possible to use a low-temperature heat source such as liquefied natural gas to extract a larger amount of cold output than a medium-temperature heat medium.

In the above device and cycle, the two working pairs are two different types of MH1 with lower equilibrium decomposition pressures.
and MH2 are each combined with MH3, which has a high equilibrium decomposition pressure, but MH3, which has a low equilibrium decomposition pressure, is combined with two different types of MH1, which have a high equilibrium decomposition pressure.
and MH2 can be combined to form two working pairs.

The second metal hydride device of the present invention uses three types of metal hydrides that have different equilibrium decomposition pressures in the operating temperature range, and has two sealed containers filled with two types of metal hydrides that have different equilibrium decomposition pressures. communicating to form a working pair so that hydrogen can move, providing at least two working pairs, and filling a closed container of one of the first working pairs with a first metal hydride having a high equilibrium decomposition pressure; A second metal hydride with the next highest equilibrium decomposition pressure is filled into one closed container of the second working pair, and a third metal hydride with the lowest equilibrium decomposition pressure is charged into the remaining one of the first and second working pairs. It is characterized by being filled in a closed container.

This device is shown in FIG.
and 4 respectively MH3, MH1, MH3 and
The structure is filled with MH2, and the connections of the heat source and heat medium are the same as in FIG.

Figure 6 shows a clockwise cycle of such a metal hydride device, with the first cycle consisting of MH1 and MH3.
The working pair performs a cycle from point A→B→C→D by the high temperature first driving heat source at temperature TH1, and the temperature
Give the cold output of TL (point C) and the thermal output of temperature TM1 (point D). The thermal output of MH1 that accompanies hydrogen transfer from MH3 to MH1 can be effectively used as needed, but it may also be released into the atmosphere at a temperature TM2 (<TM1), for example. The second working pair consisting of MH3 and MH2 performs a cycle from point E→F→G→H by means of a high temperature second driving heat source at temperature TH2, and provides a cold output at temperature TL. The thermal output (points F and H) at temperature TM2 due to hydrogen absorption of MH3 can be effectively used as necessary as described above, but it may also be released outside the system. In this way, the cold output at temperature TL is used for cooling, and the temperature TM1
(and temperature TM2) can be used for heating and hot water supply.

FIG. 7 shows a cycle diagram when two types of low-temperature driving heat sources are used in the second metal hydride apparatus of the present invention. That is, the first operating pair performs a cycle of points A→B→C→D and reaches MH3.
is the high temperature driving heat source (point A) at temperature TH and temperature TL1
are heated by the first low-temperature heat source (point C) and provide a thermal output in the medium-temperature heat transfer medium (points D and B), respectively, while the second working pair performs a cycle from points A→F→G→H. Therefore, MH3 is a high temperature drive heat source (point A)
and a second low-temperature heat source (point G) at temperature TL2, respectively, giving a thermal output in the medium-temperature heating medium (points H and F), the thermal output thus obtained being used for space heating and/or hot water supply. be able to.

In addition, in FIG. 7, as in FIG. 4, solar heat can be used at point G, and heat possessed by the atmosphere can be pumped up at point C.

The case of driving the counterclockwise cycle in this second device will be explained with reference to FIG. First, in the first working pair, when vessel 2 is connected to the first medium-temperature driving heat source to heat MH1 to temperature TM1, and vessel 1 is connected to a high-temperature heating medium to maintain MH3 at temperature TH, MH1 is Hydrogen is released endothermically (point D), and this hydrogen is exothermically occluded by MH3 (point A). On the other hand, in the second working pair, when the container 4 is connected to a low-temperature heating medium at temperature TL and the container 3 is connected to an intermediate-temperature heating medium to cause hydrogen to be released endothermically from MH3 (point F), this hydrogen is exothermically occluded by MH2 (point G).

Then, in the first working pair, when MH1 is switched to a low-temperature heating medium and connected, and MH3 is switched to and connected to a medium-temperature heating medium at a temperature of TM2, MH3 endothermically releases hydrogen (point B), and this hydrogen is occluded by MH1 (point C). On the other hand, in the second working pair,
Switch MH2 to the second medium temperature heat medium and connect it to increase the temperature.
When TM2 is heated and MH3 is switched to a high-temperature heating medium and connected, MH2 endothermically releases hydrogen (point H), and MH3 exothermically stores this hydrogen (point A). Therefore, it is possible to obtain thermal output due to hydrogen storage of MH3.

Thus, when a counterclockwise cycle is completed, a new cycle is started by connecting each vessel to the original heat source or medium. As described above, higher temperature thermal output can be obtained by using two types of medium-temperature heat sources with different temperatures.

In this counterclockwise cycle, as described above, after the hydrogen transfer between containers is completed, heat is exchanged between the high temperature container and the low temperature container to preheat the low temperature metal hydride, and also to preheat the low temperature metal hydride. It is advantageous to pre-cool the metal hydride in preparation for the next stage.

A third device of the present invention using four types of metal hydrides with different equilibrium decomposition pressures uses four types of metal hydrides with different equilibrium decomposition pressures in the operating temperature range,
Two closed containers filled with two types of metal hydrides having different equilibrium decomposition pressures are communicated so that hydrogen can move to form a working pair, and at least two of these working pairs are provided, and the one with the lowest equilibrium decomposition pressure is A first metal hydride is charged into one closed container of the first working pair, and a second metal hydride having the next lowest equilibrium decomposition pressure is charged into the second closed container.
One closed container of the working pair is filled, the third metal hydride with the highest equilibrium decomposition pressure is filled into the remaining closed container of the first or second working pair, and the fourth metal hydride with the next highest equilibrium decomposition pressure is filled. It is characterized in that the remaining closed container of the second or first working pair is filled with a metal hydride.

A cycle diagram as an example of the operation of this device is shown in FIG. The illustrated apparatus has containers 1, 2, 3 and 4 with MH1, MH3 and MH2 in FIG.
and MH4 are respectively filled, and the connections with the heat source and heat medium are the same as those shown in FIG. It will also be clear that the cycles of the first and second actuating pairs and the resulting outputs are also the same as in FIG. In addition, in Figure 9, the hydrogen transfer C'→D' is shown by the broken line arrow, but TH1, TM
2. Using four types of driving heat sources: TL and TL2,
Thermal output at the same temperature TM2 is at points B, F, H and D
It will be easy to understand what can be obtained from these four points. According to the metal hydride device of the present invention, as described above, it is possible to effectively utilize two or more drive heat sources having different temperatures at the same time to obtain thermal output and/or cold output, and therefore, the device It has a high coefficient of performance and excellent thermoeconomic efficiency.

[Brief explanation of the drawing]

FIG. 1 is a cycle diagram showing the operation of a conventional metal hydride device, FIG. 2 is a circuit diagram showing an embodiment of the metal hydride device of the present invention, and FIGS. 3 to 9
The figure is a cycle diagram showing the operation of the device of the present invention. 1, 2, 3, 4... airtight container, 5, 6, 7, 8
...Heat source or heat medium, 9,10...Communication pipe, 11,
12...Control valve, 13, 14, 15, 16, 1
7, 18, 19, 20, 21, 22... pipe line,
MH1, MH2, MH3, MH4...metal hydride.

Claims (1)

[Claims] 1. 3. Different equilibrium decomposition pressures in the operating temperature range.
Two types of metal hydrides with different equilibrium decomposition pressures were used.
Two sealed containers filled with the metal hydride of the species are communicated so that hydrogen can move to form a working pair, and at least two pairs of the working pairs are provided, and the first metal hydride having a low equilibrium decomposition pressure is used. One sealed container of the first working pair is filled, and the second
A third metal hydride having a higher equilibrium decomposition pressure is charged into the remaining closed containers of the first and second working pairs, and the first It is possible to exchange heat between the container filled with the metal hydride and the container filled with the second metal hydride, and/or between the containers filled with the third metal hydride through a heat medium conduit. A metal hydride device characterized by being connected to. 2 Different equilibrium decomposition pressures in the operating temperature range 3
Two types of metal hydrides with different equilibrium decomposition pressures were used.
Two sealed containers filled with different metal hydrides are communicated so that hydrogen can move to form a working pair, and at least two pairs of these working pairs are provided, and the first metal hydride having a large equilibrium decomposition pressure is One of the closed containers of the first working pair is filled, and the second
A third metal hydride having a lower equilibrium decomposition pressure is charged into the remaining closed containers of the first and second working pairs, and the first It is possible to exchange heat between the container filled with the metal hydride and the container filled with the second metal hydride, and/or between the containers filled with the third metal hydride through a heat medium conduit. A metal hydride device characterized by being connected to. 3 Different equilibrium decomposition pressures in the operating temperature range 4
Two types of metal hydrides with different equilibrium decomposition pressures were used.
Two sealed containers filled with the metal hydride of the species are communicated so that hydrogen can move to form a working pair, and at least two pairs of the working pairs are provided, and the first metal hydride having the lowest equilibrium decomposition pressure is provided. is charged into one sealed container of the first working pair, a second metal hydride having the next lowest equilibrium decomposition pressure is filled into one sealed container of the second working pair, and the second metal hydride having the highest equilibrium decomposition pressure is filled with Fill the remaining closed containers of the first and second working pairs with the third metal hydride, and fill the fourth metal hydride with the next highest equilibrium decomposition pressure into the remaining closed containers of the second or first working pair. At the same time, between the container filled with the first metal hydride and the container filled with the second metal hydride, and/or between the containers filled with the third metal hydride and the fourth metal hydride, 1. A metal hydride device, characterized in that the metal hydride devices are connected to each other by a heat medium conduit for heat exchange.