JPH06257884A - Heat utilization apparatus - Google Patents

Abstract

PURPOSE:To provide a heat utilization apparatus in which warm heat or cold can be continuously taken and sensible heat recovery rate can be set to a specific %. CONSTITUTION:A heat accumulator 19 is provided together with heat source side alloys 2a, 2b, 2c made of different hydrogen occlusion alloys or units 1a, 1b, 1c containing utilization side alloys 4a, 4b, 4c provided in vessels 3a, 3b, 3c, 5a, 5b, 5c, and a sensible heat recovering step for recovering sensible heat of the alloy 2a is conducted between a hydrogen discharging step and a hydrogen absorbing step of the alloy 2a between the unit 1a and the alloy 4a. Further, an operation cycle is so formed as to conduct a sensible heat preheating step for preheating the alloy 2a with heat recovered to the accumulator 19 between the hydrogen absorbing step and the hydrogen discharging step, the cycle is similarly formed also at the other units 1b, 1c, and phases are deviated and repeated, and hence sensible heat recovery rate can be set to 50% or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat utilization device such as a refrigerator or a heat pump using a hydrogen storage alloy.

[0002]

2. Description of the Related Art Refrigerators or heat pumps that use hydrogen storage alloys for heat utilization devices are characterized by the fact that they do not use CFCs, can operate with heat sources at relatively low temperatures, have a simple structure, and can be expected to have high efficiency. Research and development is being carried out to have it and put it to practical use.

A conventional technique will be described below with reference to FIG. FIG. 4 is a connection diagram of the refrigerator. Since the refrigerator and the heat pump have the same configuration and only the temperature relationship between the heat source fluid and the heat utilization fluid is different, the case of the refrigerator will be described here.

In FIG. 4, the refrigerator is composed of first and second units 1a and 1b, and each unit 1a and 1b is a container 3a and 3b containing heat source side alloys 2a and 2b made of a hydrogen storage alloy, and a heat source. A container 5a containing the utilization side alloys 4a, 4b made of a hydrogen storage alloy different from the side alloys 2a, 2b,
5b, and hydrogen pipes 7a and 7b for connecting the containers 3a and 3b and the containers 5a and 5b by inserting hydrogen valves 6a and 6b.

A fluid switching valve 8 for switching the flow of the heat source fluid A, the heat utilization fluid B, and the cooling fluid C to a heat exchange portion provided inside the vessels 3a, 3b, 5a, 5b.
a, 8b, 9a, 9b, 10a, 10b, 11a, 11
Pipes having b, 12a, 12b, 13a, 13b are connected. Further, a sensible heat recovery pipe 15 including a sensible heat recovery pump 14 is provided in the pipes on the heat source side alloys 2a and 2b side.

The refrigerator constructed as described above operates as follows. That is, in the connection state as shown in FIG. 4, the heat source fluid A is caused to flow into the container 3a of the first unit 1a, and the heat source side alloy 2a is heated through the heat exchange part thereof, and
The pressure of hydrogen absorbed in the heat source side alloy 2a in a is increased. Then, when the hydrogen valve 6a is opened, hydrogen flows to the container 5a side, and the utilization side alloy 4a absorbs hydrogen. The heat generation of the utilization side alloy 4a at this time is cooled by flowing the cooling fluid C into the heat exchange section of the container 5a.

Next, the hydrogen valve 6a is closed to close the fluid switching valve 1
0a and 11a are rotated counterclockwise by 90 ° in the figure, and the heat source side alloy 2a is cooled by flowing a cooling fluid C into the heat exchange section of the container 3a. Then, when the hydrogen valve 6a is opened, hydrogen flows from the utilization side alloy 4a of the container 5a toward the heat source side alloy 2a of the container 3a, and the utilization side alloy 4a absorbs heat in this process. At this time, the fluid switching valves 12a and 13a are rotated counterclockwise by 90 ° to transfer the heat-utilizing fluid B to the container 5a.
Cold heat is obtained by flowing the heat to the heat exchange section.

[0008] Such operation is similarly performed in the second unit 1.
b, the fluid switching valves 8a, 8b, 9a, 9
b, 10a, 10b, 11a, 11b, 12a, 12
By performing a cycle operation in which the first and second units 1a and 1b are alternately repeated while switching b, 13a, and 13b, cold heat can be obtained in the heat-utilizing fluid B, and it operates as a refrigerator.

Here, for example, when the heat source fluid A is hot water of 95 ° C. and the cooling fluid C is 30 ° C., when the heat source side alloy 2a absorbs hydrogen, the cooling fluid C is heated to about 30 ° C. It is cooled and heated to about 95 ° C. with the heat source fluid A in order to release hydrogen from this. Therefore, about 3
The heat source side alloy 2a cooled to 0 ° C. must be heated (preheated) to about 95 ° C.

At this time, the amount of heat for heating is such that both alloys 2a, 2b, 4a, 4b having a large heat capacity and the respective containers 3a, 3b, 5 are used.
It is only consumed as sensible heat for temperature changes of a and 5b, and is not used for extracting cold heat. That is, a part of the heat energy of the heat source fluid A is wasted, and the coefficient of performance (COP) of the refrigerator is lowered.

Therefore, in order to recover the sensible heat and improve the COP, the fluid switching valve 1 is moved from the position shown in FIG. 4 before switching the operations of the first and second units 1a and 1b.
0b, 11b clockwise, fluid switching valves 8a, 8b, 9
The a and 9b are rotated counterclockwise by 90 ° and the sensible heat recovery pump 14 is operated for a certain period of time to cause heat exchange between the heat source side alloys 2a and 2b. In this case, the sensible heat of the heat source side alloy that has finished releasing hydrogen can be used for preheating the heat source side alloy that releases hydrogen in the next cycle, so that COP can be improved.

On the other hand, the same applies to the utilization side alloy. When the cold heat is taken out, the utilization side alloy, which has been warmed up to about 30 ° C. in the process of absorbing hydrogen, must be cooled to the heat utilization temperature by the utilization fluid. If the sensible heat recovery pipe including the sensible heat recovery pump is connected to the pipes of the alloys 4a and 4b, the sensible heat can be recovered even in the use side alloy, and the COP can be further improved.

However, in the above-mentioned prior art,
While the sensible heat recovery process is being performed, the flow of the heat-utilizing fluid B is stopped and the operation of the refrigerator is interrupted, during which cold heat cannot be taken out. Furthermore, since heat is exchanged between the two alloys, in principle, each of the alloys 2a, 2
b, 4a and 4b reach only the intermediate temperature between them, and only half of the sensible heat can be recovered, so that the sensible heat recovery rate cannot theoretically exceed 50%.

Similarly, even when a heat pump is constructed, it is impossible to continuously take out heat.

[0015]

As described above, in the conventional device, it is not possible to continuously take out cold heat or hot heat because the sensible heat recovery process is interrupted, and the sensible heat recovery rate is 50%. It cannot be more than that. The present invention has been made in view of such a situation, and the purpose thereof is to be able to take out cold heat or warm heat substantially continuously, and the sensible heat recovery rate can be 50% or more. To provide a heat utilization device.

[0016]

The heat utilization device of the present invention comprises:
Equipped with a unit in which hydrogen storage alloys of different types are stored in multiple containers connected by piping with a switching valve inserted and hydrogen is sealed, and hydrogen is released from the hydrogen storage alloy on the heat source side with a heat source fluid for use The operation cycle is configured to perform a hydrogen releasing process of absorbing hydrogen by the hydrogen absorbing alloy on the side and a hydrogen absorbing process of releasing the hydrogen absorbed by the hydrogen absorbing alloy on the utilizing side and absorbing by the hydrogen absorbing alloy on the heat source side. In a heat utilization device configured to extract cold heat or warm heat by a heat utilization fluid while repeating an operation cycle,
Provide at least 3 pairs of units and a heat accumulator,
The sensible heat recovery process of recovering the sensible heat of the hydrogen storage alloy to the regenerator is performed between the hydrogen desorption process and the hydrogen absorption process, and the sensible heat is recovered by the heat regenerator between the hydrogen absorption process and the hydrogen desorption process. The operation cycle is configured to perform a sensible preheating or precooling process of preheating or precooling the hydrogen storage alloy,
And this operating cycle is characterized in that it is configured to be repeatedly performed by shifting the phase in each unit, and the heat accumulator uses the same fluid as the heat source fluid or the heat utilization fluid as the heat storage material. The heat storage device is characterized by comprising a cylindrical container having a displacer movable in the axial direction therein, and the heat storage device uses the same fluid as the heat source fluid or the heat utilization fluid as a heat storage material. It is characterized in that it is composed of a horizontally spirally wound pipe.

[0017]

In the heat utilization device configured as described above, at least three pairs of units each containing a different hydrogen storage alloy, which is a heat source side alloy or a utilization side alloy, are provided in a plurality of containers, and a heat accumulator is provided. A sensible heat recovery process of recovering the sensible heat of the hydrogen storage alloy in the regenerator is performed between the desorption process and the hydrogen absorption process, and hydrogen is recovered by the heat recovered in the regenerator between the hydrogen absorption process and the hydrogen desorption process. The operation cycle is configured to perform the sensible heat preheating or precooling process of preheating or precooling the storage alloy, and the operation cycle is repeatedly performed by shifting the phase in each unit. Therefore, for example, sensible heat is recovered in the regenerator from the heat source side alloy that has become high temperature after completing the hydrogen desorption process to a temperature close to the temperature of the heat source side alloy that has become low temperature after completing the hydrogen absorption process. Then, the heat recovered by this heat accumulator is used to preheat the heat source side alloy, which is at a low temperature prior to the hydrogen release process, to a temperature close to the hydrogen release temperature. Similarly, the utilization side alloy can be precooled. Then, each process is performed with a phase shift in units provided with at least three pairs. Therefore, cold heat or warm heat can be taken out almost continuously, and the sensible heat recovery rate can be 50% or more.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 for a refrigerator as one of heat utilization devices. FIG. 1 is a connection diagram, FIG. 2 is a diagram for explaining an operating state, and FIG. 3 is a schematic configuration diagram showing a modified example of the heat storage device. Since the refrigerator and the heat pump have the same configuration and only the temperature relationship between the heat source fluid and the heat utilization fluid is different, the case of the refrigerator will be described here.
Further, the same parts as those of the related art will be denoted by the same reference numerals and the description thereof will be omitted, and a configuration of the present invention different from the related art will be described.

In FIGS. 1 and 2, the refrigerator is constructed by providing first, second and third units 1a, 1b and 1c, and each unit 1a, 1b and 1c is a heat source side alloy made of a hydrogen storage alloy. Containers 3a, 3 containing 2a, 2b, 2c
b, 3c, heat source side alloys 2a, 2b, 2c, and use side alloys 4a, 4 made of hydrogen storage alloys having different temperature equilibrium pressure characteristics
b, 4c containing containers 5a, 5b, 5c, container 3a,
Hydrogen valve 6 is provided between 3b and 3c and containers 5a, 5b and 5c.
Hydrogen pipes 7a, 7 for inserting and connecting a, 6b, 6c
b, 7c.

Further, the containers 3a, 3b, 3c, 5a, 5b,
5c includes heat source side alloys 2a, 2 for switching the flow of a heat source fluid A, a heat utilization fluid B, and a cooling fluid C, which are the same fluid in different temperature states, in a heat exchange portion provided therein.
b, 2c side fluid switching valves 8a, 8b, 8c, 9a, 9
b, 9c, 10a, 10b, 10c, 11a, 11b,
11c and the fluid switching valves 8'a, 8'b, 8'c, 9'a, 9'b, 9'c on the side of the utilization side alloys 4a, 4b, 4c,
10'a, 10'b, 10'c, 11'a, 11'b,
A pipe having 11'c is connected.

Further, the sensible heat recovery pipe 1 including the sensible heat recovery pump 16 is provided in the pipes on the heat source side alloys 2a, 2b, 2c side.
7 is provided, and a heat storage device 19 whose flow direction is changed by a four-way valve 18 is provided. Similarly, the utilization side alloy 4a,
The sensible heat recovery pipe 17 'including the sensible heat recovery pump 16' is also provided in the pipes on the 4b and 4c sides, and the heat storage device 19 whose flow direction is changed by the four-way valve 18 'is also provided.

The heat accumulator 19 is composed of a cylindrical container 20 installed vertically, and the container 20 has a displacer 21 provided therein so as to be freely movable in the axial direction, and the top and bottom end portions thereof. Each of the nozzles 22 is provided with a nozzle 22 for taking a fluid in and out of the container 20. A seal ring 23, which is slidable in a liquid-tight manner on the inner wall surface of the container 20, is fitted around the displacer 21.

The refrigerator constructed as described above is the first one.
And the second and third units 1a, 1b, 1c sequentially repeat the cycle consisting of phases I to VI while shifting the phase. The operation will be described below centering on the operating state on the heat source side alloys 2a, 2b, 2c. In addition, the utilization side alloys 4a, 4
The operating states on the b and 4c sides operate similarly except that the temperature states of the heat source fluid A and the utilization fluid B are different. Also Phase I
In VI, heat source side alloys 2a, 2b, 2c side fluid switching valves 8a, 8b, 8c, 9a, 9b, 9c, 10a, 1
0b, 10c, 11a, 11b and 11c are in the positions shown in FIG.

First, looking at the operating state of the first unit 1a, in Phase I, the hydrogen release process (shown by the solid line in FIG. 2) is performed in the heat source side alloy 2a. That is, the heat source side alloy 2a is heated by the heat source fluid A of, for example, 95 ° C. flowing to the heat exchange section in the container 3a, the pressure of the absorbed hydrogen in the container 3a increases, and the hydrogen flows to the container 5a side. The utilization-side alloy 4a absorbs hydrogen. Use side alloy 4 at this time
The heat generated by a is cooled by, for example, flowing a cooling fluid C at 30 ° C. into the heat exchange section of the container 5a.

In the next phase II, the sensible heat recovery process (heat storage process of the regenerator) (shown by a chain line in FIG. 2) is performed in the heat source side alloy 2a. That is, the same fluid as the heat source fluid A is sent from the sensible heat recovery pump 16 to the heat exchange section in the container 3a from the inside of the regenerator 19 through the nozzle 22 at the top. At the same time, the sensible heat of the heat source side alloy 2a and the container 3a is recovered, the temperature of which rises and the accumulated heat returns to the inside from the nozzle 22 at the bottom of the heat accumulator 19.

At this time, the displacer 2 in the heat storage unit 19
1 moves upward from the bottom so as to be pushed upward by the fluid, and the fluid returning to the lower side of the displacer 21 releases hydrogen and the temperatures of the heat source side alloy 2a and the container 3a decrease. The temperature becomes lower as the sensible heat recovery process progresses, and a fluid layer (temperature stratification) is formed in the heat accumulator 19 in which the temperature becomes lower toward the bottom.

Similarly, the container 5a for the utilization side alloy 4a
A sensible heat recovery pump 16 'sends a fluid from the inside of the regenerator 19 through the nozzle 22 at the top to the heat exchange section therein. In addition, during continuous operation, alloy 4 on the user side
Pre-cooling of a is performed. Then, the fluid flowing through the container 5a returns to the inside of the heat storage device 19 from the nozzle 22 at the bottom of the heat storage device 19, and forms a fluid layer in the heat storage device 19 corresponding to the temperature change of the heat exchange section in the container 5a. .

Next, in phases III to IV, the heat source side alloy 2a
The hydrogen absorption process (shown by the broken line in FIG. 2) is carried out. That is, with the hydrogen valve 6a closed, the cooling fluid C is caused to flow through the heat exchange section in the container 3a to cool the heat source side alloy 2a, and when the pressure in the container 3a reaches a predetermined value, the hydrogen valve 6a is opened. Further, the heat source side alloy 2a is continuously cooled. As a result, hydrogen is released from the utilization side alloy 4a of the container 5a, flows toward the heat source side alloy 2a of the container 3a, and is absorbed by the heat source side alloy 2a. At this time, since the utilization side alloy 4a absorbs heat, the heat utilization fluid B is caused to flow to the heat exchange section in the container 5a,
This produces cold heat.

In the next phase V, the sensible heat preheating process (heat storage heat dissipation process) (shown by a two-dot chain line in FIG. 2) is performed in the heat source side alloy 2a. That is, the four-way valve 18 is switched so that the flow direction of the fluid in the sensible heat recovery pipe 17 is opposite to the sensible heat recovery process of Phase II. Then, the sensible heat recovery pump 16 sends the fluid storing heat from the inside of the regenerator 19 through the nozzle 22 at the bottom to the heat exchange section in the container 3a. The fluid fed at this time is a fluid that forms a temperature stratification in the heat accumulator 19 and has a lower temperature at the bottom and a higher temperature at the upper side. As the fluid from the low temperature to the high temperature is fed, the heat source side alloy 2a and the container 3a. Is preheated. At the same time, the fluid that preheats the heat source side alloy 2a and the container 3a is
Return to the inside from the nozzle 22 at the top of the.

At this time, the displacer 2 in the heat storage unit 19
1 moves downward from the top so that the fluid returns to the upper side of the displacer 21, and the temperature of the heat source side alloy 2a and the container 3a rises as the sensible heat preheating process progresses. Therefore, a fluid layer (temperature stratification) is formed in the heat accumulator 19 in which the temperature increases toward the top. Although the fluid temperature near the lower surface side of the displacer 21 in the heat storage unit 19 is high and the fluid temperature near the upper surface side is low, natural convection is blocked by the displacer 21 and fluids with different temperatures are Thermal mixing is maintained without mixing.

Similarly, in the utilization side alloy 4a, the sensible heat recovery pump 1 is provided in the heat exchange section in the container 5a which has a low temperature.
The fluid is sent from the inside of the heat accumulator 19 through the nozzle 22 at the top by 6 '. Then, the fluid that has passed through the container 5a and stored cold heat returns from the nozzle 22 at the bottom of the heat storage device 19 to the inside of the heat storage device 19, and a fluid layer corresponding to the temperature change of the heat exchange part in the container 5a is placed in the heat storage device 19. Form.

Then, in phase VI, the heat source side alloy 2a returns to the hydrogen release process, the heat source side alloy 2a is heated by the heat source fluid A, and the absorbed hydrogen flows from the container 3a to the container 5a side and the utilization side alloy 4a. Is absorbed by. And use side alloy 4
The heat generation of a is cooled by the cooling fluid C.

Then, each of the above-mentioned phases I to VI is repeatedly performed in the first unit 1a and thereafter, and in the second unit 1b and the third unit 1c, respectively, more than the first unit 1a. The same process is repeated with a delay of 4 phases and the phase, and the refrigerator is continuously operated.

As a result, the heat source side alloys 2a, 2b, 2c and the containers 3a, 3 which have reached a high temperature after the hydrogen release process are completed.
The sensible heat from b and 3c is recovered in the regenerator 19 to a temperature close to the temperature of the heat source side alloys 2a, 2b and 2c, which has become low temperature after finishing the hydrogen absorption process, and the heat recovered in the regenerator 19 is recovered. Then, it becomes possible to preheat the heat source side alloys 2a, 2b, 2c and the containers 3a, 3b, 3c which are cooled by the cooling fluid C and have a low temperature prior to the hydrogen releasing process to a temperature close to the hydrogen releasing temperature. That is, 50% or more sensible heat recovery is realized. Further, during the sensible heat recovery process, cold heat can be taken out substantially continuously. Similarly, the use side alloys 4a, 4b and 4c can be pre-cooled.

Next, a modified example of the heat storage device that can be used in the present invention will be described with reference to FIG. In FIG. 3, the heat storage unit 24 is configured by winding a long pipe 25 in a spiral shape and making the spiral axis direction vertical, and the winding diameter is larger than the winding pitch so that the spirally wound portion is substantially horizontal. Has become. Then, the sensible heat recovery pump 16 and the four-way valve 18 are inserted in series in the sensible heat recovery pipe 17 of the refrigerator.

The pipe 17 for recovering sensible heat constructed as described above
Since it is inserted inside, the fluid flowing into the heat storage unit 24 with a temperature gradient forms a temperature stratification with a temperature distribution in the pipe axis direction of the pipe 25. Further, even if the fluid flowing into and out of the heat storage unit 24 with a temperature gradient from both ends thereof comes into direct contact with the highest temperature fluid and the lowest temperature fluid in the pipe 25, Since 25 is wound almost horizontally, natural convection does not occur,
Mixing of the hot fluid and the cold fluid in direct contact is suppressed.

As a result, also in the heat storage unit 24 of this modification, the same effect as that of the heat storage unit 19 can be obtained with a simple structure.

The present invention is not limited to the above embodiment, but may be operated as a heat pump by exchanging the heat source fluid and the heat utilizing fluid, and the number of units may be three or more. The present invention can be appropriately modified and implemented without departing from the scope of the invention.

[0039]

As is apparent from the above description, according to the present invention, at least three pairs of units containing different hydrogen storage alloys are provided in a plurality of containers, and a heat accumulator is provided.
The sensible heat recovery process of recovering the sensible heat of the hydrogen storage alloy to the regenerator is performed between the hydrogen desorption process and the hydrogen absorption process, and the sensible heat is recovered by the heat regenerator between the hydrogen absorption process and the hydrogen desorption process. The operation cycle is configured to perform a sensible preheating or precooling process of preheating or precooling the hydrogen storage alloy,
Moreover, by adopting a configuration in which this operation cycle is repeatedly performed by shifting the phase in each unit, cold heat or warm heat can be taken out substantially continuously, and the sensible heat recovery rate can be 50% or more. And so on.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operating state of an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a modified example of the heat storage device in the present invention.

FIG. 4 is a connection diagram showing a conventional example.

[Explanation of symbols]

1a, 1b, 1c ... Unit 2a, 2b, 2c ... Heat source side alloy 3a, 3b, 3c, 5a, 5b, 5c ... Container 4a, 4b, 4c ... Utilization side alloy 6a, 6b, 6c ... Hydrogen valve 7a, 7b, 7c ... Hydrogen piping 8a, 8b, 8c, 9a, 9b, 9c, 10a, 10
b, 10c, 11a, 11b, 11c, 8'a, 8 '
b, 8'c, 9'a, 9'b, 9'c, 10'a, 1
0'b, 10'c, 11'a, 11'b, 11'c ... fluid switching valve 19 ... heat accumulator A ... heat source fluid B ... heat utilization fluid C ... cooling fluid

Claims (2)

[Claims] 1. A hydrogen storage alloy on a heat source side with a heat source fluid, comprising a unit in which hydrogen storage alloys of different types are respectively stored in a plurality of containers connected by a pipe in which a switching valve is inserted and hydrogen is sealed. A hydrogen release process of releasing hydrogen from the hydrogen storage alloy on the use side and a hydrogen absorption process of releasing the hydrogen absorbed by the hydrogen storage alloy on the use side to be absorbed by the hydrogen storage alloy on the heat source side. In the heat utilization device configured as described above, wherein cold heat or warm heat is taken out by the heat utilization fluid while repeating this operation cycle, at least three pairs of the units are provided and a heat accumulator is provided, and the hydrogen release process is performed. Between the hydrogen absorption process and the hydrogen absorption process, the sensible heat recovery process of recovering the sensible heat of the hydrogen storage alloy to the heat storage device is performed, and the hydrogen absorption process and the hydrogen release process are performed. The operation cycle is configured so as to perform a sensible heat preheating or precooling process of preheating or precooling the hydrogen storage alloy by the heat recovered in the regenerator between the steps, and the operation cycle is phased in each unit. A heat-utilizing device characterized in that the heat-dissipating device is arranged so as to be repeatedly operated by shifting. 2. The regenerator comprises a cylindrical container having a displacer axially movable therein as a heat storage material or the same fluid as a heat source fluid or a heat utilization fluid, or spirally wound substantially horizontally. The heat utilization device according to claim 1, wherein the heat utilization device comprises a pipe.