JP2003262391A - Hot-water supply system using hydrogen occluded alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain COP of not less than 1.0 by clearing not less than 80% of obtained heat value of heated water in regard to the heat value of combustion gas in a hot-water supply system using combustion of fuel. <P>SOLUTION: If a cold output is obtained by a two-stage cycle, the output can be obtained only in two stages during one cycle (a first, a second, a third hydrogen driving). However, in the hot-water supply system 1 adopting a heat pump using hydrogen occluded alloy, the supply hot-water output can be obtained in all stages during one cycle. A low temperature heating medium is heated by using exhaust heat of a combustion device 4 used for heating high temperature heating medium. Therefore, the discharging speed of hydrogen at the second and third hydrogen driving can be hastened, and the practical COP of the supply hot-water output can be improved. Consequently, in the hot-water supply system 1 supplying hot-water by using the combustion of the fuel, the practical COP of not less than 1.0 can be obtained. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a hydrogen storage alloy that causes a hydrogen storage alloy to repeatedly store and release hydrogen to obtain heat for tapping by utilizing an exothermic action generated during hydrogen storage. Regarding the hot water heater.

[0002]

2. Description of the Related Art A water heater using combustion of fuel (eg, gas) is known. This water heater has a burner that burns fuel, a passage that guides the combustion heat generated by the burner together with the combustion gas to an exhaust port, and a combustion heat that flows inside the passage and hot water that is discharged from the passage. And a heat exchanger for exchanging heat with water).

On the other hand, as a system using a hydrogen storage alloy, hydrogen is absorbed and released by the hydrogen storage alloy repeatedly to obtain cold heat by utilizing the endothermic action generated at the time of release of hydrogen, and at the time of storage of hydrogen. A heat pump cycle is known in which heat is generated by utilizing the generated heat generation effect.
An example of a heat pump cycle using this hydrogen storage alloy will be described using a two-stage refrigeration cycle.

The refrigerating two-stage cycle is a first encapsulation of a high temperature alloy among high temperature, medium temperature and low temperature hydrogen storage alloys (hereinafter, high, medium and low temperature alloys) having the same equilibrium hydrogen pressure but different hydrogen equilibrium temperatures. A chamber, a second chamber for enclosing the medium temperature alloy, and a third chamber for enclosing the low temperature alloy, and is configured to repeatedly perform the first hydrogen drive → second hydrogen drive → third hydrogen drive. A cold heat output is obtained in the second stage driven by the third hydrogen.

In the first hydrogen drive, the high temperature alloy in the first chamber and the heat medium for high temperature heating are heat-exchanged to release the hydrogen stored in the high temperature alloy in the first chamber and the low temperature alloy in the third chamber. And the heat storage medium for hydrogen storage are heat-exchanged to store hydrogen in the low temperature alloy in the third chamber. In the second hydrogen drive, the medium temperature alloy in the second chamber and the heat medium for hydrogen storage are heat-exchanged to store hydrogen in the medium temperature alloy in the second chamber, and the low temperature alloy in the third chamber and the heat for low temperature heating are stored. It exchanges heat with the medium to release hydrogen stored in the low temperature alloy in the third chamber. Further, the third hydrogen drive causes the high temperature alloy in the first chamber and the heat medium for hydrogen storage to exchange heat with each other so that the high temperature alloy in the first chamber stores hydrogen, and the medium temperature alloy in the second chamber and the heat for low temperature heating. It exchanges heat with the medium to release hydrogen stored in the medium temperature alloy in the second chamber.

[0006]

In recent years, in the field of electric equipment, a "vapor compression heat pump" has been developed which is advantageous in heating water by using carbon dioxide as a refrigerant and operating in a supercritical region. COP as an electric water heater for home use
It enabled 3.0 and started to appear on the market as an energy-saving device.

However, in the above-described water heater utilizing combustion of fuel, the acquired heat quantity of hot water obtained by heating water with respect to the heat quantity of combustion gas is currently 80% or more.
In addition, a condensed water heater has appeared, which recovers the heat contained in the exhaust gas discharged as condensation heat, and the amount of heat obtained from hot water has reached 95%. However, in a water heater that discharges hot water using the heat of combustion of fuel, theoretically, the upper limit is 100% (heat efficiency = COP1.0) for the amount of heat obtained from hot water.

For this reason, it is considered indispensable to adopt a heat pump type which makes the running cost low in a water heater utilizing combustion of fuel. Here, in the above-mentioned two-stage cycle of refrigeration using a hydrogen storage alloy, heat is generated in three stages of the first, second, and third hydrogen drives during one cycle of the first hydrogen drive → second hydrogen drive → third hydrogen drive. You can get the output.

In the two-stage refrigeration cycle using this hydrogen storage alloy, as described above, the cold heat output is the second during the first cycle (in the three stages of the first hydrogen drive → second hydrogen drive → third hydrogen drive). , While the third hydrogen-driven two stages are obtained, while the thermal output is obtained in the first, second, and third hydrogen-driven three stages in one cycle (three stages), it is better than the cold heat output. A COP with a higher thermal output can be expected.

However, under the present circumstances, in the first hydrogen drive, the heating medium (combustion device) is used to heat the high temperature heating heat medium for releasing the hydrogen stored in the high temperature alloy in the first chamber. The heat medium for low temperature heating, which releases hydrogen stored in the low temperature alloy in the third chamber during driving,
Since the heat medium for low-temperature heating that releases hydrogen stored in the medium temperature alloy in the second chamber in hydrogen driving also absorbs heat both indoors and outdoors, in the second and third hydrogen driving,
A large pressure difference was hard to occur, and a high COP could not be obtained.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to use a hydrogen storage alloy capable of obtaining a COP of 1.0 or more in a water heater utilizing combustion heat of fuel. In the provision of a water heater.

[0012]

The water heater using the hydrogen storage alloy of the present invention employs the following technical means in order to achieve the above object. (Means of claim 1) A water heater using a hydrogen storage alloy,
A first chamber enclosing a high temperature hydrogen storage alloy having a high hydrogen equilibrium temperature at the same equilibrium hydrogen pressure, and a second chamber enclosing a low temperature hydrogen storage alloy having a low hydrogen equilibrium temperature at the same equilibrium hydrogen pressure; The high temperature hydrogen storage alloy in the first chamber and the heat medium for high temperature heating are heat-exchanged to release the hydrogen stored in the high temperature hydrogen storage alloy in the first chamber and the low temperature hydrogen storage alloy in the second chamber. A first hydrogen drive for exchanging heat between the heat storage medium and the heat storage medium for hydrogen storage to store hydrogen in the low temperature hydrogen storage alloy in the second chamber; and a high temperature hydrogen storage alloy and the heat storage medium for hydrogen storage in the first chamber. Of the low temperature hydrogen storage alloy in the second chamber and the heat medium for low temperature heating to exchange the low temperature hydrogen storage alloy in the second chamber with the low temperature hydrogen storage alloy in the second chamber. Temperature Releases hydrogen stored in the hydrogen storage alloy. The second hydrogen drive is alternately performed, and the heat of the hydrogen storage heat medium obtained during the first hydrogen drive and the heat of the hydrogen storage heat medium obtained during the second hydrogen drive are both used. Is for tapping,
The heating medium for high temperature heating used when driving the first hydrogen is
The low-temperature heating heat medium that is provided so as to be heated by the combustion heat generated by the combustion device that burns the fuel and that is used when driving the second hydrogen is not only atmospheric heat but also the combustion heat generated by the combustion device. Among them, it is characterized in that it is provided so as to be heated by utilizing the exhaust heat after heating the heating medium for high temperature heating.

(Means for Claim 2) A water heater using a hydrogen storage alloy is a high temperature hydrogen storage alloy among high temperature, medium temperature and low temperature hydrogen storage alloys having different hydrogen equilibrium temperatures at the same equilibrium hydrogen pressure. A first chamber for enclosing, a second chamber for enclosing an intermediate temperature hydrogen storage alloy, and a third chamber for enclosing a low temperature hydrogen storage alloy are provided, and the high temperature hydrogen storage alloy and the heat medium for high temperature heating in the first chamber are provided. While exchanging heat to release hydrogen stored in the high temperature hydrogen storage alloy in the first chamber, heat exchange between the low temperature hydrogen storage alloy in the third chamber and the heat medium for hydrogen storage is performed in the third chamber. The first hydrogen drive for storing hydrogen in the low temperature hydrogen storage alloy and the medium temperature hydrogen storage alloy for the second chamber and the heat medium for hydrogen storage heat exchange to heat the medium temperature hydrogen storage alloy for the second chamber. Of the low temperature hydrogen in the third chamber. Second hydrogen drive for exchanging heat between the alloy and the heat medium for low temperature heating to release hydrogen stored in the low temperature hydrogen storage alloy in the third chamber, and high temperature hydrogen storage alloy and hydrogen storage in the first chamber By exchanging heat with a heat medium, the first
The hydrogen stored in the high temperature hydrogen storage alloy in the room is exchanged with the medium temperature hydrogen storage alloy in the second chamber and the heat medium for low temperature heating, and the hydrogen stored in the medium temperature hydrogen storage alloy in the second chamber is stored. The third hydrogen drive for releasing hydrogen is repeatedly performed, and the heat of the hydrogen storage heat medium obtained during the first hydrogen drive, the heat of the hydrogen storage heat medium obtained during the second hydrogen drive, and the third Hot water is discharged by each heat of the hydrogen storage heat medium obtained during hydrogen driving, and the high temperature heating heat medium used during the first hydrogen driving is generated by a combustion device that burns fuel. The heat medium for low-temperature heating, which is provided so as to be heated by the heat of combustion that is used for driving the second and third hydrogen, heats the heat medium for high-temperature heating of the combustion heat generated by the combustion device. It is characterized in that it is provided so as to be heated by utilizing the waste heat after.

(Means for Claim 3) In a water heater using the hydrogen storage alloy according to claim 1 or 2, the hot water discharged is heated by utilizing the combustion heat generated by the combustion device. It is characterized by having an additional heat unit.

(Means of claim 4) In the water heater using the hydrogen storage alloy according to claim 3, the additional heat unit is a heat medium for high temperature heating which is heated by the combustion heat generated by the combustion device. A liquid-liquid heat exchanger for exchanging heat with the hot water discharged is provided.

(Means of claim 5) In the water heater using the hydrogen storage alloy according to claim 3, the additional heat unit is arranged in a combustion duct of the combustion device to generate combustion heat and discharge hot water. It is characterized by including a gas-liquid heat exchanger for exchanging heat with hot water.

[0017]

(Operation and effect of the invention) (Operation and effect of claim 1) The water heater using the hydrogen storage alloy adopting the means of claim 1 is a one-stage cycle (first and second hydrogen) using the hydrogen storage alloy. In driving, a cycle for extracting cold heat output by the second hydrogen drive), and the first hydrogen drive → second hydrogen drive is repeatedly performed. In this one-stage cycle, the cold heat output is obtained by only one stage of the second hydrogen drive in one cycle (in the two stages of the first and second hydrogen drives), whereas the heat output is obtained in one cycle (two stages of the hydrogen drive). In the middle), COP having a higher thermal output than a cold output can be expected because it can be obtained by two stages of the first and second hydrogen drives. In other words, if the ideal COP of the cold heat output is 1.0, the warm heat output (hereinafter, hot water output)
Has an ideal COP of 2.0 and is excellent in energy saving.

The water heater using the hydrogen storage alloy adopting the means of claim 1 heats the heat medium for low temperature heating by using the combustion device used for heating the heat medium for high temperature heating. Is provided. Therefore, the temperature of the low-temperature heating heat medium for heating the low-temperature hydrogen storage alloy in the second chamber rises during the second hydrogen drive, and the release rate of hydrogen stored in the low-temperature hydrogen storage alloy in the second chamber is increased. Therefore, the practical COP of the hot water output can be further increased. At this time, the heat for heating the low-temperature heating heat medium uses the exhaust heat after heating the high-temperature heating heat medium, so that the temperature of the high-temperature heating heat medium is not lowered and the capability of the combustion device is not increased. That is, the COP of the hot water output can be increased regardless of the temperature of the heating medium for high temperature heating and the capacity of the combustion device.

As described above, the heat pump utilizing the hydrogen storage alloy is used, and C of the hot water output is obtained by the above two functions.
By raising OP, it becomes possible to obtain a practical COP of 1.0 or more in a water heater that uses hot water to burn hot water.

(Operation and effect of claim 2) A water heater using a hydrogen storage alloy adopting the means of claim 2 is a two-stage cycle (first, second, third hydrogen drive) using a hydrogen storage alloy. In the second) and the third hydrogen drive to take out the cold heat output), the first hydrogen drive → the second hydrogen drive →
The third hydrogen drive is repeated. In this two-step cycle,
Cold output is obtained in 2 stages of 2nd and 3rd hydrogen drive during 1 cycle (in 3 stages of 1st, 2nd and 3rd hydrogen drive), while thermal output is obtained in 1 cycle (3 stages of 3 stage). In ()), COP having a higher thermal output than a cold output can be expected because it can be obtained in three stages of the first, second and third hydrogen drives.
That is, if the ideal COP of the cold heat output is 2.0, the ideal COP of the hot heat output (hereinafter, hot water output) is 3.0, which is excellent in energy saving.

The water heater using the hydrogen storage alloy adopting the means of claim 2 heats the heat medium for low temperature heating by using the combustion device used for heating the heat medium for high temperature heating. Is provided. Therefore, a low temperature heating heat medium that heats the low temperature hydrogen storage alloy in the third chamber when driving the second hydrogen and a low temperature heating heat medium that heats the medium temperature hydrogen storage alloy in the second chamber when driving the third hydrogen are used. The temperature rises. This makes it possible to increase the release rate of hydrogen stored in the low temperature hydrogen storage alloy in the third chamber during the second hydrogen drive, and to increase the hydrogen stored in the medium temperature hydrogen storage alloy in the second chamber during the third hydrogen drive. The discharge rate can be increased, and the practical COP of the hot water output can be further increased. At this time, the heat for heating the low-temperature heating heat medium uses the exhaust heat after heating the high-temperature heating heat medium, so that the temperature of the high-temperature heating heat medium is not lowered and the capability of the combustion device is not increased. That is, the COP of the hot water output can be increased regardless of the temperature of the heating medium for high temperature heating and the capacity of the combustion device.

As described above, the heat pump utilizing the hydrogen storage alloy is used, and C of the hot water output is obtained by the above-mentioned two actions.
By increasing OP, it becomes possible to obtain a practical COP of 1.0 or more in a water heater that uses fuel combustion to discharge hot water.

(Operation and effect of claim 3) The water heater using the hydrogen storage alloy adopting the means of claim 3 is an additional heat for heating the hot water discharged by using the combustion heat generated by the combustion device. Since the unit is provided, the temperature of the hot water discharged from the water heater using the hydrogen storage alloy can be increased.

(Operation and effect of claim 4) The water heater using the hydrogen storage alloy adopting the means of claim 4 is, as an additional heat unit, a high temperature heating heat heated by the combustion heat generated by the combustion device. By using a liquid-liquid heat exchanger that exchanges heat between the medium and the hot water discharged, it is possible to raise the temperature of the hot water discharged.

(Operation and effect of claim 5) The water heater using the hydrogen storage alloy adopting the means of claim 5 is disposed as an additional heat unit in the combustion duct of the combustion device to generate heat of combustion. Willingness to exchange heat with the hot water
By using the liquid heat exchanger, it is possible to raise the temperature of the hot water discharged.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described based on two examples and modifications. [Structure of First Embodiment] In the first embodiment, a heat medium flowing in a cycle (heat medium for high temperature heating, heat medium for low temperature heating,
As a heat medium for hydrogen storage, a water heater using brine (LLC) as a boiling point raising agent mixed in water (a water heater using a hydrogen storage alloy) is shown. The water heater used (hereinafter referred to as a water heater) will be described with reference to FIGS. 1 to 4.

(Schematic Description of Water Heater 1) The schematic configuration of the water heater 1 of this embodiment will be described with reference to FIG. The water heater 1
A hot water producing unit 2 using a hydrogen storage alloy, a heat medium for high temperature heating, a heat medium for low temperature heating, a heat medium distributor 3 for switching the heat medium for hydrogen storage to supply the hot water producing unit 2, and a fuel (for example, Gas), a combustion device 4, a high temperature heating unit 5 for heating the high temperature heating heat medium to a predetermined temperature (eg, 128 ° C.), and a low temperature heating heat medium to a predetermined temperature (eg, 20 ° C.) Low temperature heating unit 6 for heating
And a tapping unit 7 for heating water (hot water) tapped by a heat medium for hydrogen storage (for example, 42 ° C.) that has absorbed heat in the tapping unit 2, and the hot water heated by the tapping unit 7 is further heated. And an additional heating unit 8 for

(Description of Hot Water Making Unit 2) Hot Water Making Unit 2
Is a refrigeration two-stage cycle that uses a hydrogen storage alloy that can output two times in one cycle if it is a cold heat output, and as shown in FIG. 2, the upper heat exchange module N1 and the middle heat It consists of an exchange module N2 and a lower heat exchange module N3, and in FIG. 1, for convenience, one of the three stages is shown.

One module is composed of a plurality of cells S and a housing 9. The cell S is, as shown in FIG.
A first chamber S1 in which a hydrogen storage alloy is enclosed, this first chamber S1
A second chamber S2 in which the hydrogen storage alloy is sealed, and a second chamber S2 in which the hydrogen storage alloy is sealed, and a second chamber S3 in which the hydrogen storage alloy is sealed and which communicates in the second chamber S2 through the hydrogen passage S4. Equipped with. The housing 9 includes first, second and third chambers S1 and S.
2, Independently for each of S3 and S3, a passage for flowing a heat medium is formed.

Hydrogen storage alloys have different hydrogen equilibrium pressures.
The seed is used, and a powder of a high temperature hydrogen storage alloy (hereinafter, high temperature alloy HM) having the highest hydrogen equilibrium temperature at the same equilibrium hydrogen pressure is enclosed in the first chamber S1, and the second chamber S2 is filled with the powder. Is a medium temperature hydrogen storage alloy (hereinafter referred to as medium temperature alloy MM) powder, and a low temperature hydrogen storage alloy (hereinafter referred to as low temperature alloy LM) having the lowest hydrogen equilibrium temperature at the same equilibrium hydrogen pressure in the third chamber S3.
The powder is encapsulated. This will be described with reference to the PT refrigeration cycle diagram of FIG. 4. The characteristics of the hydrogen storage alloy are relatively high temperature side (the left side in the drawing) and high temperature alloy HM and low temperature side (the right side in the drawing). Is the low temperature alloy LM, and the medium temperature alloy MM is between them.

(Description of Heat Medium Distributor 3) The heat medium distributor 3 is
As shown in FIG. 2, the heat medium switching supply of the heat medium distributor 3 causes each module of the hot water making unit 2 to forcibly move the hydrogen in the first chamber S1 into the third chamber S3.
The hydrogen drive α and the hydrogen that has moved into the third chamber S3 are transferred to the second chamber S3.
The second hydrogen drive β for moving to 2 and the third hydrogen drive γ for moving the hydrogen moved into the second chamber S2 to the first chamber S1 are sequentially switched.

In the first hydrogen drive α, the heat medium for high temperature heating is supplied to the first chamber S1 and the heat medium for boosting pressure (heat generated from the heat medium for high temperature heating in the heat medium distributor 3) is supplied to the second chamber S2. Medium), and the hydrogen storage heat medium is supplied to the third chamber S3. In the second hydrogen drive β, the pressurizing heat medium is supplied to the first chamber S1, the hydrogen storage heat medium is supplied to the second chamber S2, and the low temperature heating heat medium is supplied to the third chamber S3. Third
In the hydrogen-driven γ, the hydrogen storage heat medium is supplied to the first chamber S1, and the low temperature heating heat medium is supplied to the second chamber S2. The temperature of the heat medium to the third chamber S3 does not matter, and it may be provided so that nothing is supplied to the third chamber S3.

That is, by the heat medium distributor 3, the first chamber S1
Is a heating medium for high temperature heating → a heating medium for boosting → a heating medium for hydrogen storage that is sequentially switched and supplied, and a heating medium for boosting → a hydrogen storage heat medium → a heating medium for low temperature heating is supplied to the second chamber S2. Are sequentially switched and supplied, and the hydrogen storage heat medium → low temperature heating heat medium → heat medium no matter is sequentially switched and supplied to the third chamber S3.

(Description of Other Units Constituting Hot Water Heater 1) The combustion device 4 burns gas as fuel to generate heat, and heats the heat medium for high temperature heating by the generated heat,
The heat medium for low temperature heating is heated by the exhaust heat after heating the heat medium for high temperature heating. The gas burner 11 burns gas, the gas supply means 12 for supplying gas to the gas burner 11, and the gas burner 11. It is composed of a combustion fan 13 that supplies combustion air, a combustion duct 14 that guides the combustion heat obtained by the combustion of gas to the exhaust port together with the exhaust gas, and the like. A high temperature heating unit 5 (gas-liquid heat exchanger) for heating the heat medium for high temperature heating by combustion heat is arranged on the upstream side (lower side in FIG. 1) of the combustion duct 14, and the downstream side (upper side in FIG. 1) thereof. ), A low-temperature heating unit 6 (gas-liquid heat exchanger) that heats the low-temperature heating heat medium by utilizing the exhaust heat after heating the high-temperature heating heat medium is arranged.

The high temperature heating unit 5 and the heat medium distributor 3
In the heat medium circuit 21 that connects with the heat medium distributor 3, the heat medium for high temperature heating is guided from the heat medium distributor 3 to the high temperature heating unit 5, and the heat medium for high temperature heating heated by the high temperature heating unit 5 is again supplied to the heat medium distributor 3 A heat medium pump P1 for heating at high temperature is arranged. Further, in the heat medium circuit 22 that connects the low temperature heating unit 6 and the heat medium distributor 3, the heat medium for low temperature heating is introduced from the heat medium distributor 3 to the low temperature heating unit 6 and heated by the low temperature heating unit 6. The heat medium for low temperature heating is again divided into the heat medium distributor 3
A heat medium pump P2 for low temperature heating that leads to

On the other hand, the hot water unit 7 is a liquid-liquid heat exchanger that heats the water supplied from the water supply port 24 by the heat medium for hydrogen occlusion which absorbs heat during hydrogen occlusion and rises in temperature. In the heat medium circuit 23 connecting to the heat medium distributor 3, a heat medium for hydrogen storage is introduced from the heat medium distributor 3 to the hot water unit 7, and is cooled by being heat-exchanged with water in the hot water unit 7. A hydrogen storage heat medium pump P3 for guiding the heat medium to the heat medium distributor 3 again is arranged.

The additional heating unit 8 is the high temperature heating unit 5
By the heat medium for high temperature heating introduced to the
Is a liquid-liquid heat exchanger that additionally heats the hot water that has passed through, and the hot water that has passed through the additional heat unit 8 is guided to the hot water outlet 25.

(Description of Operation of Hot Water Making Unit 2) The operation of the hot water making unit 2 in the water heater 1 will be described with reference to the PT refrigeration cycle diagram of FIG. The solid line in FIG. 4 is the refrigeration cycle diagram used in the water heater 1, and the broken line in the figure is the refrigeration cycle diagram for obtaining the cold heat output (the diagram shown for reference). is there. When an operation start instruction is given to the water heater 1, the heat medium distributor 3, the combustion device 4, and the heat medium pumps P1, P2, P3 are operated by a control device (not shown).

Then, the operation of the heat medium distributor 3 causes the first
High-temperature heating heat medium → pressurizing heat medium → hydrogen storage heat medium is sequentially switched and supplied to the chamber S1, and boosting heat medium → hydrogen storage heat medium → low temperature heating heat medium is sequentially supplied to the second chamber S2. Switching supply is performed, and the hydrogen storage heat medium → low temperature heating heat medium → heat medium no matter is sequentially switched and supplied to the third chamber S3. As a result, the upper heat exchange module N1 is
Hydrogen driving β → third hydrogen driving γ is repeated, and the middle heat exchange module N2 is driven by the second hydrogen driving β → third hydrogen driving γ → first.
The hydrogen driving α is repeated, and the lower heat exchange module N3 repeats the third hydrogen driving γ → the first hydrogen driving α → the second hydrogen driving β.

In the first hydrogen drive α, the first chamber S1 is in contact with the heat medium for high temperature heating (in FIG. 4), the third chamber S3 is in contact with the heat medium for hydrogen storage (in FIG. 4), and the second chamber S2 is in contact. Touches the heat medium for boosting. When the first chamber S1 touches the heat medium for high temperature heating (shown in FIG. 4), the internal pressure of the first chamber S1 rises,
The high temperature alloy HM releases hydrogen. When the third chamber S3 touches the hydrogen storage heat medium (in FIG. 4), the third chamber S3
The internal pressure of the alloy decreases, and the low temperature alloy LM absorbs hydrogen. At this time, the hydrogen storage heat medium absorbs heat generated when the low temperature alloy LM stores hydrogen, and the temperature of the hydrogen storage heat medium rises. When the second chamber S2 comes into contact with the pressurizing heat medium, the internal pressure of the second chamber S2 rises to a pressure at which the intermediate temperature alloy MM does not store hydrogen.

In the second hydrogen drive β, the third chamber S3 comes into contact with the heat medium for low temperature heating (in FIG. 4). The second chamber S2 contacts the hydrogen storage heat medium (in FIG. 4), and the first chamber S1 contacts the boosting heat medium. When the third chamber S3 touches the heat medium for low temperature heating (shown in FIG. 4), the internal pressure of the third chamber S3 rises,
The low temperature alloy LM releases hydrogen. When the second chamber S2 comes into contact with the heat medium for hydrogen storage (see FIG. 4), the second chamber S2
The internal pressure of is decreased, and the medium temperature alloy MM absorbs hydrogen. At this time, the hydrogen storage heat medium absorbs heat generated when the medium temperature alloy MM stores hydrogen, and the temperature of the hydrogen storage heat medium rises. When the first chamber S1 comes into contact with the heating medium for pressurization, the internal pressure of the first chamber S1 rises to a pressure at which the high temperature alloy HM does not store hydrogen.

In the third hydrogen drive γ, the second chamber S2 touches the low temperature heating heat medium (in FIG. 4), the first chamber S1 touches the hydrogen storage heat medium (in FIG. 4) and the third chamber S3. Touches the water. When the second chamber S2 comes into contact with the heating medium for low temperature heating (shown in FIG. 4), the internal pressure of the second chamber S2 rises and the medium temperature alloy MM releases hydrogen. When the first chamber S1 comes into contact with the hydrogen storage heat medium (shown in FIG. 4), the internal pressure of the first chamber S1 drops, and the high temperature alloy HM stores hydrogen. At this time, the hydrogen storage heat medium absorbs heat generated when the high temperature alloy HM stores hydrogen, and the temperature of the hydrogen storage heat medium rises.

(Explanation of Operation of Water Heater 1) As described above,
The heat medium for hydrogen storage absorbs heat and the temperature of the heat medium for hydrogen storage rises in each step of the first, second, and third hydrogen driving α, β, γ. The hydrogen storage heat medium whose temperature has risen in this manner is heat-exchanged with water in the hot water unit 7 to heat the hot water to be heated to, for example, about 42 ° C. Hot water unit 7
In the additional heating unit 8, the hot water heated in (1) is heat-exchanged with the heat medium for high-temperature heating introduced to the high-temperature heating unit 5, and the hot water discharged is, for example, higher than the temperature of the hot-melting unit 2 (for example, 42 or higher). ℃ or more).

[Effects of Embodiment] Since the water heater 1 shown in the above embodiment employs the heat pump of the two-stage refrigeration cycle, one cycle (first, second, third hydrogen drive α,
The tap water output can be obtained in all stages of β, γ). That is, if cold heat output is obtained in the heat pump of the two-stage refrigeration cycle, only two stages can be obtained in one cycle, but in the present embodiment, all three outputs in one cycle.
The output for tapping is obtained in the stage. Therefore, the practical COP of the cold heat output of the two-stage refrigeration cycle is the theoretical COP.
A value of 1.0, which is half of 2.0, is a practical COP for hot water output.
Is 1.5, which is half of the theoretical COP of 3.0, and is excellent in energy saving.

Further, the combustion device 4 used for heating the heating medium for high temperature heating is used to heat the heating medium for low temperature heating. Therefore, the heat medium for low temperature heating that heats the low temperature alloy LM in the third chamber S3 during the second hydrogen drive β, and the heat medium for low temperature heating that heats the medium temperature alloy MM in the second chamber S2 during the third hydrogen drive γ. The temperature of the medium rises. This makes it possible to accelerate the release rate of hydrogen stored in the low temperature alloy LM in the third chamber S3 during the second hydrogen drive β, and to store the medium temperature alloy MM in the second chamber S2 during the third hydrogen drive γ. The release rate of hydrogen can be increased, and the COP of the hot water output can be further increased.
At this time, since the heat for heating the low-temperature heating heat medium uses the exhaust heat after heating the high-temperature heating heat medium, the temperature of the high-temperature heating heat medium is not lowered and the capacity of the combustion device 4 is not increased. . That is, the COP of the hot water output can be increased regardless of the temperature of the heating medium for high temperature heating and the capacity of the combustion device 4.

As described above, the heat pump utilizing the hydrogen storage alloy is used, and C of the hot water output is obtained by the above-mentioned two actions.
By raising OP, it becomes possible to obtain a practical COP of 1.0 or more in the water heater 1 that uses the combustion of fuel to discharge hot water.

Table 1 below shows practical COP calculation results for the water heater 1 having the above-described structure at the output No. 6 (9000 kcal / h).

[Table 1] In Table 1 above, the thermal efficiency obtained by the combustion of gas is 80%, and the loss due to the hot water making unit 2 is 40%.
3 times during the cycle (first, second, third hydrogen driven α, β,
Calculations are made assuming that the tapping output (exothermic output due to hydrogen storage) of γ three times) is obtained. For the sake of convenience, it was assumed that there was no loss of heat exchange in the hot water discharge unit 7 and the additional heat unit 8.

As shown in Table 1, when the No. 6 hot water supply capacity (No. 1 is the ability to raise 1 liter of water by 25 ° per minute) is obtained (when no additional heat is added by the additional heating unit 8). ), COP 1.7 for input energy
1 can be realized.

When a large amount of hot water is obtained by using the additional heating unit 8 together or a high amount of hot water is obtained, the obtained COP of the heating medium for high temperature heating flowing in the additional heating unit 8 is 0.8. Therefore, the COP decreases as the load of the additional heat unit 8 increases with respect to the hot water making unit 2. COP 1.0 or more can be secured until the hot water supply capacity of No. 6 of the hot water producing unit 2 becomes about 9, and the total hot water supply capacity of No. 15 reaches about 15.

[Second Embodiment] A second embodiment will be described with reference to FIG. The same reference numerals as those in the first embodiment indicate the same functional objects. The second embodiment is a modification of the first embodiment described above. The first change will be described. In the above-mentioned first embodiment, the example in which the brine mixed liquid in which the boiling point of water is raised is used as the heat medium is shown. On the other hand, the second embodiment uses water as the heat medium. When the hot water making unit 2 has 2 stages or 3
Even in the case of a stage, it is possible under a combination of high temperature, medium temperature, low temperature alloy and other conditions. By using water as the heat medium in this manner, the water can be directly used as the heat medium for storing hydrogen, and thus the water used as the heat medium for storing hydrogen is provided so as to be discharged.

The second change will be described. The additional heat unit 8 of the first embodiment described above is an example of a liquid-liquid heat exchanger that exchanges heat between the high-temperature heating heat medium that has undergone heat exchange in the hot water producing unit 2 and the hot water discharged. In contrast, this second
The additional heat unit 8 of the embodiment is arranged in the combustion duct 14 of the combustion device 4 and uses a gas-liquid heat exchanger that heats the hot water discharged by the combustion heat flowing in the combustion duct 14. . The additional heat unit 8 (gas-liquid heat exchanger) of this embodiment is provided in the combustion duct 14 so as to be arranged between the high temperature heating unit 5 and the low temperature heating unit 6.

[Modification] In the above embodiment, an example of using a two-stage cycle as an example of the hot water making unit 2 is shown, but it may be used in a one-stage cycle, or a three-stage type or more. You may use for a cycle. In the above-described embodiment, the example in which the gas is burned is shown as the burner 4 for heating the heat medium for high temperature heating, but the burner 4 for burning other fuel such as burning petroleum may be used. . In the above embodiment, only the water heater 1 that obtains hot water by utilizing the exothermic action that occurs when hydrogen is absorbed by the hydrogen absorbing alloy has been shown as an example. It is also possible to adopt a mode in which it is implemented in combination with a device for obtaining cold heat (for example, a cooling device).

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a water heater (first embodiment).

FIG. 2 is a perspective view of a hot water making unit and a heat medium distributor (first embodiment).

FIG. 3 is a schematic sectional view of a cell (first embodiment).

FIG. 4 is a PT refrigeration cycle diagram (first embodiment).

FIG. 5 is a schematic configuration diagram of a water heater (second embodiment).

[Explanation of symbols]

1 water heater 2 Hot water unit 3 Heat medium distributor 4 Combustion device 5 High temperature heating unit 6 Low temperature heating unit 7 Hot water unit 8 additional heat unit 14 Combustion duct S1 Room 1 S2 second room S3 Room 3 HM high temperature alloy (high temperature hydrogen storage alloy) MM Medium Temperature Alloy (Medium Temperature Hydrogen Storage Alloy) LM low temperature alloy (low temperature hydrogen storage alloy) α 1st hydrogen drive β Second hydrogen drive γ Third hydrogen drive

Claims (5)

[Claims] 1. A first chamber for enclosing a high temperature hydrogen storage alloy having a high hydrogen equilibrium temperature at the same equilibrium hydrogen pressure, and a second chamber enclosing a low temperature hydrogen storage alloy having a low hydrogen equilibrium temperature at the same equilibrium hydrogen pressure. A high-temperature hydrogen storage alloy in the first chamber and a heat medium for high-temperature heating are heat-exchanged to release hydrogen stored in the high-temperature hydrogen storage alloy in the first chamber, and in the second chamber. A first low temperature hydrogen storage alloy and a heat medium for hydrogen storage heat exchange to cause hydrogen to be stored in the low temperature hydrogen storage alloy in the second chamber.
While driving the hydrogen, the high temperature hydrogen storage alloy in the first chamber and the heat medium for hydrogen storage are heat-exchanged to cause the high temperature hydrogen storage alloy in the first chamber to store hydrogen, and the low temperature in the second chamber. A second method for exchanging heat between a hydrogen storage alloy and a low temperature heating heat medium to release hydrogen stored in the low temperature hydrogen storage alloy in the second chamber.
Hydrogen driving is alternately performed, and hot water is discharged by both heat of the hydrogen storage heat medium obtained during the first hydrogen drive and heat of the hydrogen storage heat medium obtained during the second hydrogen drive. In a water heater using a hydrogen storage alloy, the high-temperature heating heat medium used when driving the first hydrogen is:
The heat medium for low-temperature heating, which is provided so as to be heated by the combustion heat generated by the combustion device that burns fuel, and is used at the time of driving the second hydrogen,
In addition to atmospheric heat, among the combustion heat generated by the combustion device, a hydrogen storage alloy is used which is provided so as to be heated by using exhaust heat after heating the heating medium for high temperature heating. Water heater. 2. A first chamber for enclosing a high temperature hydrogen storage alloy among high, medium and low temperature hydrogen storage alloys having the same equilibrium hydrogen pressure but different hydrogen equilibrium temperatures, and a first chamber for enclosing a medium temperature hydrogen storage alloy. Two chambers, a third chamber for enclosing a low-temperature hydrogen storage alloy, are provided, and the high-temperature hydrogen storage alloy in the first chamber and the heat medium for high temperature heating are heat-exchanged so that the high-temperature hydrogen storage alloy in the first chamber First, the hydrogen stored therein is released, and the low temperature hydrogen storage alloy in the third chamber and the heat storage medium for hydrogen storage are heat-exchanged to store hydrogen in the low temperature hydrogen storage alloy inside the third chamber.
Hydrogen driving and heat exchange between the medium temperature hydrogen storage alloy and the heat medium for hydrogen storage in the second chamber to cause hydrogen to be stored in the medium temperature hydrogen storage alloy in the second chamber, and a low temperature in the third chamber A second method for exchanging heat between a hydrogen storage alloy and a low temperature heating heat medium to release hydrogen stored in the low temperature hydrogen storage alloy in the third chamber.
While driving the hydrogen, the high temperature hydrogen storage alloy in the first chamber and the heat medium for hydrogen storage are heat-exchanged to store hydrogen in the high temperature hydrogen storage alloy in the first chamber, and the medium temperature in the second chamber. Third, heat exchange between the hydrogen storage alloy and the heat medium for low-temperature heating to release hydrogen stored in the medium temperature hydrogen storage alloy in the second chamber
The hydrogen driving is repeated to obtain the heat of the hydrogen storage heat medium obtained during the first hydrogen drive, the heat of the hydrogen storage heat medium obtained during the second hydrogen drive, and the heat during the third hydrogen drive. In a water heater using a hydrogen storage alloy that discharges hot water with each of the heat of the heat storage medium for hydrogen storage, a high-temperature heating heat medium used when driving the first hydrogen,
The heat medium for low-temperature heating, which is provided so as to be heated by the combustion heat generated by the combustion device that burns the fuel and is used when driving the second and third hydrogens, is one of the combustion heat generated by the combustion device. A water heater using a hydrogen storage alloy, which is provided so as to be heated by using exhaust heat after heating a heating medium for high temperature heating. 3. A water heater using the hydrogen storage alloy according to claim 1 or 2, further comprising an additional heat unit for heating the hot water to be discharged by using the combustion heat generated by the combustion device. A water heater that uses a hydrogen storage alloy. 4. The water heater using the hydrogen storage alloy according to claim 3, wherein the additional heat unit is a high temperature heating heat medium heated by the combustion heat generated by the combustion device, and hot water discharged from the hot water. A water heater using a hydrogen storage alloy, comprising a liquid-liquid heat exchanger for exchanging heat between and. 5. The water heater using the hydrogen storage alloy according to claim 3, wherein the additional heat unit is arranged in a combustion duct of the combustion device to generate heat of combustion and hot water to be discharged. A water heater using a hydrogen storage alloy, comprising a gas-liquid heat exchanger for exchange.