WO2019163365A1

WO2019163365A1 - Magneto-caloric element and magnetic heat pump device

Info

Publication number: WO2019163365A1
Application number: PCT/JP2019/001749
Authority: WO
Inventors: 善民横田; 相哲 ▲裴▼; 清水　圭一; 一也茂木; 裕介山口; 龍一近藤
Original assignee: サンデンホールディングス株式会社
Priority date: 2018-02-23
Filing date: 2019-01-22
Publication date: 2019-08-29
Also published as: JP2019143938A

Abstract

[Problem] To provide: a magneto-caloric element with which heat exchange efficiency, such as refrigeration capacity, can be further improved by a simple design; and a magnetic heat pump device using the same. [Solution] This magneto-caloric element 20 for magnetic heat pumps has a plurality of magnetic bodies having different Curie temperatures and arranged sequentially along an axial direction, in the order of the Curie temperatures thereof. If the magnetic body having a lower Curie temperature among adjacent magnetic bodies is referred to as a low-side magnetic body and the magnetic body having a higher Curie temperature among the adjacent magnetic bodies is referred to as a high-side magnetic body, the intersection point P between the entropy variation curve of the material constituting the low-side magnetic body and the entropy variation curve of the material constituting the high-side magnetic body is located at a position at which the entropy variation value is higher than the half-value width 9 of the entropy variation distribution of the material constituting the low-side magnetic body.

Description

Magneto-caloric element and magnetic heat pump device

The present invention relates to a magnetocaloric element in which a plurality of magnetic bodies are arranged in cascade, and a technique related to a magnetic heat pump apparatus using the magnetocaloric element.

In the magnetic refrigeration heat pump apparatus, as described in Patent Document 1, a plurality of work chambers 2 are arranged along the circumferential direction on the outer peripheral side of a permanent magnet fixed to a rotating shaft, and each of the work chambers 2 has a magnetic heat quantity. The magnetic body 6 which comprises an element is accommodated (refer FIG. 1). In addition, in synchronization with the rotation of the permanent magnet 3, there is provided a valve for adjusting inflow / outflow of the heat conduction medium (work fluid such as water) to the magnetic body 6 in the work chamber 2.
The opening part of the axial direction edge part of each working chamber 2 is obstruct | occluded by the communicating hole plate 1 shown, for example in patent document 1 and FIG. 1, and the communicating hole to each working room 2 is made into the communicating hole plate 1 (valve plate). 1a and 1b are formed. The

communication holes

1a and 1b constitute, for example, an outflow communication hole on the outer peripheral side and an inflow communication hole on the inner peripheral side.

In FIG. 1, the case where the rotary disk 4 of a rotary valve is provided in the front side of the communicating hole plate 1 is illustrated. The rotating disk 4 rotates in synchronization with the permanent magnet 3. The rotating disk 4 is formed with slit-

shaped notches

4a and 4b extending in the circumferential direction as valve ports, and the flow of the heat transfer medium into and out of each working chamber is controlled via the

notches

4a and 4b. Done. Here, for example, of the slit-

shaped notches

4a and 4b, the outer peripheral side is for outflow, and the inner peripheral side is for inflow.
Here, the valve applied to the magnetic refrigeration heat pump apparatus to which the present invention is applied may not be a rotary valve.
In addition, for the purpose of improving the heat exchange efficiency, as described in Patent Document 2, the work chamber is filled with a plurality of types of magnetic materials stacked (arranged) in cascade (in series). ing.

Japanese Patent No. 5488580 Japanese Patent No. 5884806

In the magnetic heat pump device, the heat conduction medium is pumped to each work chamber in a form that is synchronized with the demagnetization and excitation repeated to the magnetic material in the work chamber by the permanent magnet, so that the low temperature in the demagnetization area and the excitation area Take out the high temperature.
The present invention has been made paying attention to the above points, and provides a magnetocaloric element capable of further improving the heat exchange efficiency such as refrigeration capacity by a simple design and a magnetic heat pump device using the magnetocaloric element. Objective.

In order to solve the problem, the magnetocaloric element of one aspect of the present invention is a magnetocaloric element for a magnetic heat pump device in which a plurality of magnetic bodies having different Curie temperatures are arranged in series along the axial direction, For adjacent magnetic materials, a material that constitutes a low-side magnetic material when the magnetic material having a lower Curie temperature is a low-side magnetic material and the magnetic material having a higher Curie temperature is a high-side magnetic material. The crossing position of the entropy change curve of the material and the entropy change curve of the material constituting the high-side magnetic material is a position where the entropy change value is higher than the half-value width of the entropy change distribution of the material constituting the low-side magnetic material Is the gist.

The gist of the magnetic heat pump device according to one aspect of the present invention is to employ the magnetocaloric element according to the above aspect as the magnetocaloric element to which the heat transfer medium is supplied.

According to one aspect of the present invention, when a plurality of types of magnetic bodies having different Curie temperatures are arranged in a stack, a plurality of types having different Curie temperatures are considered in consideration of the half-value width of the entropy change distribution of the material constituting each magnetic body. By arranging the magnetic bodies in series, it is possible to extract heat more efficiently with a simple configuration.
Furthermore, regarding the peak value of the distribution of the adiabatic temperature change of each material constituting the plurality of magnetic bodies, the peak value of the magnetic body having the lowest distribution value of the adiabatic temperature change and the peak value of the distribution of the adiabatic temperature change are the most. The temperature difference from the peak value of the high magnetic material is set to 18% or less of the peak value of the magnetic material having the lowest peak value of the adiabatic temperature change distribution, more preferably set so that there is no temperature difference. The plurality of magnetic bodies can be set to the same amount (equal intervals), and the magnetocaloric element can be easily manufactured.

It is a schematic exploded view explaining the structure of a magnetic refrigeration heat pump apparatus. It is sectional drawing which illustrates the arrangement | sequence of the magnetocaloric element based on this invention. It is a figure which illustrates the overlap of an entropy change curve.

Next, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
(Constitution)
The basic configuration of the magnetic refrigeration heat pump apparatus of this embodiment is the same as the conventional configuration shown in FIG. 1, but the configuration of the magnetocaloric elements 20 arranged in the circumferential direction is different.
As shown in FIG. 2, the basic configuration of the magnetic refrigeration heat pump of the present embodiment is such that a permanent magnet 3 is fixed to a rotating shaft 10 that is rotationally driven by a motor (not shown). A plurality of work chambers 2 each containing a magnetocaloric element 20 are arranged on the outer periphery of the permanent magnet 3. The plurality of work chambers 2 are arranged along the circumferential direction so as to form an annular shape concentric with the rotation shaft 10. Further, an annular yoke (not shown) is provided on the outer peripheral side of the plurality of work chambers 2.

The opening at the axial end of each work chamber 2 is closed by a communication hole plate 1, and a communication hole to each work chamber 2 is formed in the communication hole plate 1 (valve plate) (see FIG. 1). ). On the front side of the communication hole plate 1 is disposed a rotary disc 4 of a rotary valve that rotates with the rotation of the permanent magnet 3 (see FIG. 1). A slit-shaped notch extending in the circumferential direction opens as a valve port on the rotating disk 4, and the flow of heat transfer medium is controlled through the slit. For example, among the slits, the outer peripheral side is for outflow and the inner peripheral side is for inflow (see FIG. 1).
Here, as for the configuration other than the magnetocaloric element 20 described below, the configuration of a known magnetic refrigeration heat pump device may be adopted. In addition, the magnetocaloric element 20 of the present embodiment is not limited to the magnetic refrigeration heat pump apparatus, and can be applied as long as it is a magnetic heat pump apparatus using the magnetocaloric effect. The structure of the heat pump device can be applied as appropriate.

<Magnetic calorific element 20>
In each working chamber 2, a magnetocaloric element 20 is arranged along the axial direction. In the magnetocaloric element 20, the plurality of magnetic bodies M are arranged in order from the material having the low Curie temperature with respect to each working chamber 2 (in FIG. 2, the Curie temperature increases in the order from the left side to the right side in FIG. 2). It is configured to be accommodated along the direction. FIG. 2 exemplifies a case where the plurality of magnetic bodies M to be accommodated are five types, and it is assumed that the Curie temperatures of the materials of the five types of magnetic bodies M have the following relationship.
M1 <M2 <M3 <M4 <M5

As shown in FIG. 2, the five types of magnetic bodies M are sequentially accommodated in the work chamber 2 so that the lengths in the arrangement direction are equal, that is, the respective masses are equal. Are arranged in series.
As the five types of magnetic bodies M, materials having substantially equal peak values ΔTad of the distribution of adiabatic temperature change are used.
In the present embodiment, a magnetic body M made of a manganese-based material is used, and one having a peak value ΔTad of each adiabatic temperature change distribution in the vicinity of 1.6 (K) is employed.

Specifically, regarding the peak value ΔTad of the adiabatic temperature change distribution of each material constituting the plurality of magnetic bodies, the peak value of the magnetic body having the lowest peak value of the adiabatic temperature change distribution and the peak value of the adiabatic temperature change distribution are the most. The material is selected so that the temperature difference from the peak value of the magnetic material having a high value becomes 18% or less of the peak value of the magnetic material having the lowest peak value of the adiabatic temperature change distribution.
Here, examples of the magnetic material capable of setting the peak value ΔTad of each adiabatic temperature change to substantially the same value include lanthanum-based materials, lanthanum-based hydrogenated materials, and gadolinium-based materials in addition to manganese-based materials.

As a result of the inventor's confirmation, ΔTad = 1.6K ± 32% for manganese-based and lanthanum-based materials, and ΔTad = 2.9K ± 18% for lanthanum-based hydrogenated materials, the magnetic bodies M are equally spaced. It was confirmed that it was possible to arrange them in series. For this reason, the temperature difference of the peak value ΔTad is set to 18% or less. The temperature difference of the peak value ΔTad is preferably 10% or less, more preferably 5% or less.
Here, the five types of magnetic bodies M adopt the same series of materials and adjust the blending ratio to adjust the entropy change distribution and the Curie temperature while aligning the peak values ΔTad of each adiabatic temperature change distribution. It is possible.

In the present embodiment, as shown in FIG. 3, for the adjacent magnetic bodies, the magnetic body having a relatively low Curie temperature is used as the low-side magnetic body (left side in FIG. 3), and the Curie temperature is on the high side. When the magnetic body is a high-side magnetic body (right side in FIG. 3), the intersection position P between the entropy change curve of the material constituting the low-side magnetic body and the entropy change curve of the material constituting the high-side magnetic body is The entropy change value Δs is set to be higher than the half-value width 9 of the entropy change distribution of the material constituting the low-side magnetic body.
The crossing position P is not particularly problematic as long as the entropy change value is higher than the half-value width 9 of the entropy change of the material composing the low-side magnetic material, but the entropy change distribution of the material composing the low-side magnetic material is not problematic. It is preferable to cross at a position of 80% or less of the peak value. If the peak values of adjacent magnetic materials are too close, if there is no difference in the peak value ΔTad, the difference in Curie temperature between adjacent magnetic materials may be unnecessarily small.

In the setting example shown in FIG. 3, the Curie temperature is set higher from the left side to the right side, and among the adjacent magnetic bodies, the magnetic substance on the left side is at a higher temperature than the peak value in the entropy change curve of the left magnetic body. The Curie temperature of the right magnetic material relative to the left magnetic material is relatively set so that the lower temperature curve intersects the peak value in the entropy change curve of the right magnetic material at a position higher than the half-value width 9. design.
Here, FIG. 3 illustrates the case where the peak value of the entropy change distribution increases as the Curie temperature increases, but the present invention is not limited to this. A material having a relatively low peak value of the entropy change distribution of the magnetic substance in the middle may be disposed.
As described above, in this embodiment, the Curie temperature of each magnetic material M is not determined and designed first, but is designed so that the curves of the respective entropy change distributions have the above relationship, thereby providing five types of magnetic properties. The Curie temperature of the body M is specified. For this reason, the five types of magnetic bodies M are not necessarily arranged so that the Curie temperatures are increased at regular temperature intervals.

(Operation other)
Along with the rotation of the permanent magnet 3, a magnetic field is applied (excited) to the magnetic body M on the side close to the magnetic pole of the permanent magnet 3 to be heated, and the magnetic body M demagnetized away from the magnetic pole of the permanent magnet 3 has a temperature. Falls and becomes low temperature.
At this time, by setting the relationship between the entropy change distributions of the adjacent magnetic bodies as described above, the latent heat as a whole is increased, and the heat exchange efficiency is further increased between the low temperature and the high temperature by the magnetic bodies M arranged in series. However, it can be taken out as a large amount of heat. In this embodiment, it was confirmed that a high refrigeration capacity can be obtained.

Further, by aligning the peak value ΔTad of the distribution of the adiabatic temperature change of the plurality of magnetic bodies M arranged in series, the plurality of magnetic bodies are filled in equal amounts, that is, simply at equal intervals to produce the magnetocaloric element 20. it can. For this reason, compared with the structure of patent document 2, the manufacture operation | work of the magnetocaloric element 20 becomes easy, improving heat exchange efficiency.
Further, since it is not necessary to align the peak values of the entropy change distribution of each magnetic body M, it is not necessary to narrow the selection range of the magnetic material used as the magnetic body M.
In the present embodiment, a granular material is assumed as the magnetic material. However, other forms of magnetic material may be used.

Here, when the inventor confirmed, about entropy change (DELTA) s, if it is at least the following range, it has also confirmed that a performance can be ensured by equivalent filling.
Manganese material: 8.5 J / kgK ± 43%
Lanthanum material: 3.9 J / kgK ± 16%
Lanthanum hydrogenation material: 11.4J / kgK ± 29%
That is, even if a plurality of magnetic bodies are arranged in equal amounts, it is not necessary to make the peak values of the entropy change distributions of the plurality of magnetic bodies arranged in series the same value. That is, the material selection conditions do not become severe.
Here, in the above description, the case where a plurality of magnetic bodies arranged in series are equally spaced is illustrated, but there may be a slight difference in length. For example, the length difference may be 10% or less.

2 Work chamber 3 Permanent magnet 9 Half width 10 Rotating shaft 20 Magneto-caloric element M Magnetic body P Crossing position

Claims

A magnetocaloric element for a magnetic heat pump device, in which a plurality of magnetic bodies having different Curie temperatures are arranged in series along the axial direction,
For adjacent magnetic bodies, when the magnetic body on the side with a low Curie temperature is a low-side magnetic body and the magnetic body on the side with a high Curie temperature is a high-side magnetic body,
The intersection of the entropy change curve of the material composing the low-side magnetic material and the entropy change curve of the material composing the high-side magnetic material is more entropy than the half-value width of the entropy change distribution of the material composing the low-side magnetic material. A magnetocaloric element for a magnetic heat pump device, characterized in that the change value is at a high position.
The magnetocaloric element for a magnetic heat pump device according to claim 1, wherein the peak value of at least one entropy change distribution of the plurality of magnetic bodies is different from the peak value of the entropy change distribution of other magnetic bodies.
About the peak value of the distribution of the adiabatic temperature change of each material constituting the plurality of magnetic bodies, the peak value of the magnetic body having the lowest distribution value of the adiabatic temperature change and the highest peak value of the distribution of the adiabatic temperature change are the highest. 3. The magnetic heat pump according to claim 1, wherein the temperature difference from the peak value of the magnetic material is 18% or less of the peak value of the magnetic material having the lowest peak value of the adiabatic temperature change distribution. Magneto-caloric element for equipment.
4. The magnetocaloric element for a magnetic heat pump device according to claim 1, wherein the plurality of magnetic bodies arranged in series are arranged at equal intervals.
A permanent magnet rotatable around a central axis, and a plurality of magnetocaloric elements arranged in parallel in the circumferential direction and arranged in an annular shape on the outer peripheral side of the permanent magnet, each of the magnetocaloric elements being connected to the axis of the apparatus A magnetic heat pump device extending along a direction,
5. A magnetic heat pump device according to claim 1, wherein the magnetocaloric element is the magnetocaloric element according to any one of claims 1 to 4.