WO2024052960A1

WO2024052960A1 - Magnetocalorific material bed and magnetic refrigeration device

Info

Publication number: WO2024052960A1
Application number: PCT/JP2022/033279
Authority: WO
Inventors: 俊圭鈴木; 有理子西村
Original assignee: 三菱電機株式会社
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2024-03-14

Abstract

The present invention obtains a magnetocalorific material bed in which a heat-storing member is provided to a flow path within which a plurality of types of magnetocalorific materials are provided so that the Curie temperatures thereof sequentially increase from one end toward the other end, thereby making it possible to cause the magnetocalorific materials to swiftly reach the respective Curie temperatures when a device is started up, and making it possible to improve the operation efficiency.　This magnetocalorific material bed (10) comprises: a flow path (20) through which a heat exchange fluid (9) flows in a circulatory manner between one end and the other end; a plurality of types of magnetocalorific materials (21) that are provided within the flow path (20) such that the Curie temperatures of the magnetocalorific materials (21) sequentially increase from the one end to the other end, the magnetocalorific materials (21) undergoing heat exchange with the heat exchange fluid (9); and a plurality of types of heat-storing members (22) that are provided to the flow path (20) so that the phase transition temperatures of the heat-storing members (22) sequentially increase from the one end to the other end.

Description

Magnetocaloric material beds and magnetic refrigeration equipment

The present disclosure relates to magnetocaloric material beds and magnetic refrigeration devices.

A magnetic refrigeration device is a refrigeration system that utilizes the phenomenon that when a magnetic field is applied to a magnetic body, the magnetic body generates heat, and when the magnetic field is removed, the magnetic body absorbs heat (hereinafter referred to as "magnetocaloric effect"). It is known that magnetocaloric materials used as magnetic materials in magnetic refrigeration devices exhibit the largest magnetocaloric effect near the Curie point, where the entropy change is large.

In the conventional technology, magnetocaloric materials with different characteristics filled in a magnetocaloric container are arranged in a cascade from the low temperature side to the high temperature side, thereby increasing the temperature difference between both ends and improving the cooling performance. For example, in Patent Document 1, an element is arranged so as to form a cascade in which the Curie temperature increases from a low temperature end to a high temperature end, and an element with a relatively low fluid resistance is higher than an element with a relatively high fluid resistance. A magnetocaloric effect element and a magnetocaloric cycle device located on the high temperature side are disclosed.

JP2020-077745A

The above-mentioned magnetocaloric effect element and magnetocaloric cycle device realize a magnetocaloric cycle device with high refrigerating capacity by arranging each magnetocaloric element in a cascade and operating at a temperature with a large amount of heat absorption and heat absorption. On the other hand, it takes time for each magnetocaloric element to reach its Curie temperature when starting up the device, such as at the initial stage of startup or when restarting the device.

The present disclosure has been made in order to solve the above-mentioned problems, and the magnetocaloric material quickly reaches close to the Curie temperature at the beginning of operation of the magnetic refrigeration equipment, such as at the initial startup stage or at the time of restarting, so that it can be efficiently The objective is to obtain a magnetocaloric material bed and a magnetic refrigeration device that can exhibit refrigeration capacity.

The magnetocaloric material bed according to the present disclosure has a flow path in which a heat exchange fluid flows back and forth between one end and the other end, and heat exchanges with the heat exchange fluid such that the Curie temperature increases in order from one end to the other end. A plurality of types of magnetocaloric materials are provided in the flow path, and a plurality of types of heat storage materials are provided in the flow path such that the phase transition temperature increases in order from one end to the other. A heat storage material having a phase transition temperature higher than the Curie temperature of the magnetocaloric material is provided in the flow path provided with the magnetocaloric material having a low Curie temperature, and a magnetocaloric material having a Curie temperature higher than the operating environment temperature is provided. A heat storage material having a phase transition temperature lower than the Curie temperature of the magnetocaloric material is provided in the flow path.

According to the magnetocaloric material bed of the present disclosure, a heat storage material having a phase transition temperature higher than the Curie temperature of the magnetocaloric material is provided in the channel provided with the magnetocaloric material having a Curie temperature lower than the operating environment temperature, A heat storage material whose phase transition temperature is lower than the Curie temperature of the magnetocaloric material is provided in the flow path containing the magnetocaloric material whose Curie temperature is higher than the operating environment temperature, so that each This has the effect of allowing the magnetocaloric material to quickly reach the Curie temperature and improving operational efficiency.

1 is a schematic diagram of a magnetic refrigeration device according to a first embodiment. FIG. 2 is a sectional view taken along the line AA in FIG. 1 of the magnetocaloric material bed according to the first embodiment. FIG. 2 is a sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed according to the first embodiment. FIG. 3 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material. FIG. 3 is a diagram showing a temperature change of the magnetocaloric material at the other end side of the magnetocaloric material bed according to the first embodiment. FIG. 2 is a sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed according to the first embodiment. FIG. 3 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material. FIG. 2 is a cross-sectional view of a heat storage material covered with a capsule provided in a flow path of a magnetocaloric material bed according to a first embodiment. FIG. 2 is a diagram in which a magnetocaloric material is provided so as to straddle one end side and the other end side in the channel of the magnetocaloric material bed according to the first embodiment. FIG. 3 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material. FIG. 2 is a diagram in which a magnetocaloric material is provided so as to straddle one end side and the other end side in the channel of the magnetocaloric material bed according to the first embodiment. FIG. 3 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material. FIG. 7 is a cross-sectional view of a heat storage material covered with a magnetocaloric material capsule provided in a flow path of a magnetocaloric material bed according to a second embodiment. FIG. 2 is a sectional view taken along line AA in FIG. 1 of the magnetocaloric material bed according to Embodiment 3;

Hereinafter, embodiments will be described in detail based on the drawings. Note that the embodiment described below is an example. Moreover, each embodiment can be executed in combination as appropriate.

Embodiment 1.
FIG. 1 is a schematic diagram of a magnetic refrigeration device according to a first embodiment. FIG. 2 is a sectional view taken along the line AA shown in FIG. 1 of the magnetocaloric material bed according to the first embodiment. FIG. 3 is a sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed according to the first embodiment. FIG. 4 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed and the phase transition temperature of the heat storage material according to the first embodiment. FIG. 5 is a diagram showing a temperature change of the magnetocaloric material at the other end side of the magnetocaloric material bed according to the first embodiment. FIG. 6 is a sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed according to the first embodiment. FIG. 7 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed and the phase transition temperature of the heat storage material according to the first embodiment. FIG. 8 is a sectional view of a heat storage material covered with a capsule provided in a flow path of a magnetocaloric material bed according to the first embodiment. FIG. 9 is a diagram in which the magnetocaloric material is provided so as to straddle the low temperature side and the high temperature side in the flow path of the magnetocaloric material bed according to the first embodiment. FIG. 10 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material. FIG. 11 is a diagram in which the magnetocaloric material is provided so as to straddle the low temperature side and the high temperature side in the flow path of the magnetocaloric material bed according to the first embodiment. FIG. 12 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material provided in the flow path of the magnetocaloric material bed according to the first embodiment and the phase transition temperature of the heat storage material.

As shown in FIG. 1, the magnetic refrigeration device 1 includes a low-temperature side heat exchanger 2, a high-temperature side heat exchanger 3, a fan 4, a pump 5, a magnetic field modulator 6, a water tube 7, and a magnetocaloric material bed 10. The magnetocaloric material bed 10 will be described in detail later.

Here, the magnetic refrigeration device 1 is a heat pump system that makes one of the channels 20 of the magnetocaloric material bed 10 high temperature and the other channel 20 low temperature. Therefore, the channel 20 of the magnetocaloric material bed 10 has a high temperature side that is a high temperature region and a low temperature side that is a low temperature region. Further, the position with the highest temperature on the high temperature side is defined as the high temperature end, and the position with the lowest temperature on the low temperature side is defined as the low temperature end. That is, in the flow path 20, the high temperature end and the low temperature end refer to the vicinity of the outlet when the heat exchange fluid 9 is transported from the flow path 20 to the water tube 7.

The low temperature side heat exchanger 2 is connected to the low temperature end of the flow path 20 of the magnetocaloric material bed 10 via the water pipe 7. Further, a cooled medium flow path (not shown) is connected to the low temperature side heat exchanger 2, and is supplied from the low temperature end of the flow path 20 of the magnetocaloric material bed 10 to the low temperature side heat exchanger 2 via the water pipe 7. The heated heat exchange fluid 9 exchanges heat with the medium to be cooled flowing through the medium flow path. That is, the heat exchange fluid 9 supplied to the low temperature side heat exchanger 2 exchanges heat with the medium to be cooled and absorbs heat. Note that the medium to be cooled here refers to a liquid such as water.

Here, the heat exchange fluid 9 is a fluid flowing through the flow paths 20 of the low temperature side heat exchanger 2, the high temperature side heat exchanger 3, the water tubes 7, and the magnetocaloric material bed 10, and is It reciprocates between the high temperature side heat exchanger 3 and the high temperature side heat exchanger 3. For example, water, brine, etc. may be used as the heat exchange fluid 9.

The high temperature side heat exchanger 3 is connected to the high temperature end of the flow path 20 of the magnetocaloric material bed 10 via the water pipe 7. Therefore, the low temperature side heat exchanger 2 and the high temperature side heat exchanger 3 are connected to sandwich the magnetocaloric material bed 10 via the water pipe 7. As shown in FIG. 1, the heat exchange fluid 9 is supplied to the high temperature side heat exchanger 3 from the high temperature end of the flow path 20 of the magnetocaloric material bed 10 via the water pipe 7. A fan 4 is provided for exchanging heat between the air and the air. That is, the heat exchange fluid 9 supplied to the high temperature side heat exchanger 3 exchanges heat with air to exhaust heat, and the heat exchanged air is transported by the fan 4.

Here, an example has been shown in which the heat exchange fluid 9 supplied to the low temperature side heat exchanger 2 exchanges heat with a medium to be cooled such as water, but the present invention is not limited to this. For example, when the medium to be cooled is air, the heat exchange fluid 9 supplied to the low temperature side heat exchanger 2 exchanges heat with the air, and the air with which the heat exchange has been performed is transported using the fan 4. Similarly, the heat exchange fluid 9 supplied to the high temperature side heat exchanger 3 may exchange heat with a liquid such as water. In other words, the partner with which the heat exchange fluid 9 performs heat exchange can be changed depending on the application.

The pump 5 is a reciprocating pump configured to be able to transport the heat exchange fluid 9 between the low temperature side heat exchanger 2 and the high temperature side heat exchanger 3 so as to reciprocate via the magnetocaloric material bed 10. . That is, the pump 5 transports the heat exchange fluid 9 repeatedly between the low-temperature side heat exchanger 2, the magnetocaloric material bed 10, and the high-temperature side heat exchanger 3.

Note that although FIG. 1 shows a pump 5 connected via a water pipe 7 between the low-temperature side heat exchanger 2 and the high-temperature side heat exchanger 3 on the side opposite to the magnetocaloric material bed 10, the pump The connection position of No. 5 is not limited to this. For example, a connection may be made between the magnetocaloric material bed 10 and the low temperature side heat exchanger 2 or between the magnetocaloric material bed 10 and the high temperature side heat exchanger 3 via the water pipe 7. However, in this case, due to the heat capacity of the pump 5, the temperature difference between the high-temperature end and the low-temperature end of the flow path 20 of the magnetocaloric material bed 10 becomes small. It is desirable to connect the exchanger 2 and the high temperature side heat exchanger 3 via water pipes 7.

As shown in FIG. 1, the magnetic field modulators 6 are provided facing each other so as to sandwich the entire side surface of the magnetocaloric material bed 10. Further, the magnetic field modulator 6 is configured to be able to vary the magnetic field applied to the magnetocaloric material 21 provided in the flow path 20 of the magnetocaloric material bed 10.

The magnetic field modulation device 6 may be of any type as long as it can apply and remove a magnetic field to and from the magnetocaloric material 21 provided in the channel 20 of the magnetocaloric material bed 10. For example, in the case of the magnetic field modulation device 6 using a permanent magnet, the magnetocaloric material bed 10 is fixed, and the magnetic field is varied by moving the permanent magnet closer to or away from the magnetocaloric material bed 10. Alternatively, the permanent magnet may be fixed and the magnetic field may be varied by moving the magnetocaloric material bed 10 closer to or away from the permanent magnet. However, in the case of the magnetic field modulator 6 using a permanent magnet, if the magnetic field modulator 6 is far from the magnetocaloric material bed 10, the magnetic force of the permanent magnet will weaken and a sufficient magnetic field cannot be applied. It is preferable to provide it close to the magnetic field modulator 6.

Furthermore, in the case of the magnetic field modulation device 6 using an electromagnet, it is excited by passing a current, and demagnetized by stopping it, thereby imparting fluctuations in the magnetic field to the magnetocaloric material 21. In this case, since the magnetic field can be varied by flowing or stopping the current, the magnetic field modulator 6 does not need to be installed close to the magnetocaloric material bed 10, and if the magnetic field can be applied to and removed from the magnetocaloric material 21, the magnetic field modulator 6 can be installed at any location. , the installation method does not matter.

The water pipe 7 is connected between the low temperature side heat exchanger 2 and the magnetocaloric material bed 10, between the high temperature side heat exchanger 3 and the magnetocaloric material bed 10, between the low temperature side heat exchanger 2 and the pump 5, and between the high temperature side heat exchanger 2 and the magnetocaloric material bed 10. This piping is provided between the side heat exchanger 3 and the pump 5 and transports the heat exchange fluid 9. Note that the shape of the water tube 7 is not limited to that shown in FIG. 1, and may be changed as appropriate.

The magnetocaloric material bed 10 will be explained using FIGS. 2 and 3. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is a sectional view taken along the line AA shown in FIG. 1 of a modified example of the magnetocaloric material bed 10. As shown in FIG. 2, the magnetocaloric material bed 10 includes a flow path 20 formed by the flange 12 and the bed wall 11.

The flange 12 is provided at the low temperature end and high temperature end of the flow path 20 and connects the water pipe 7 and the flow path 20. Note that although FIG. 2 shows the magnetocaloric material bed 10 to which the water pipe 7 is connected via the flange 12, this is merely an example, and the water pipe 7 and the flow path 20 may be directly connected without using the flange 12. It's okay.

The flow path 20 is formed by the bed wall 11 and is a waterway through which the heat exchange fluid 9 flows. The flow path 20 has a low temperature end at one end and a high temperature end at the other end, and the heat exchange fluid 9 supplied from the low temperature side heat exchanger 2 via the water pipe 7 flows from one end of the flow path 20 to the other end. It flows. Similarly, the heat exchange fluid 9 supplied from the high temperature side heat exchanger 3 via the water pipe 7 flows from the other end of the flow path 20 toward one end. That is, the heat exchange fluid 9 flows back and forth between one end and the other end of the flow path 20 by the pump 5 .

Additionally, a magnetocaloric material 21 that exchanges heat with the heat exchange fluid 9 is provided within the flow path 20 . The magnetocaloric material 21 is provided in the flow path 20 such that the Curie temperature thereof increases from one end of the flow path 20 to the other end. Here, the Curie temperature is the temperature at which a magnetic material loses its magnetic force.

Next, details of the magnetocaloric material 21 provided in the flow path 20 will be explained using FIG. 2. As shown in FIG. 2, four different types of

magnetocaloric materials

21a, 21b, 21c, and 21d are provided in the flow path 20. Further, the magnetocaloric material 21 is composed of a plurality of grains, and a plurality of types of magnetocaloric materials 21 each composed of a plurality of grains are provided in the channel 20. Here, the Curie temperature of the magnetocaloric material 21 is set as

magnetocaloric materials

21a, 21b, 21c, and 21d in descending order of Curie temperature.

In the channel 20 of the magnetocaloric material bed 10 in this embodiment, the magnetocaloric material 21 is provided with a magnetocaloric material 21a at one end of the channel 20, and whose Curie temperature increases toward the other end. is provided. That is, the magnetocaloric materials 21 are provided in the channel 20 in the order of

magnetocaloric materials

21a, 21b, 21c, and 21d from one end of the channel 20 to the other end.

Note that arranging the magnetocaloric material 21 having a high Curie temperature from the low-temperature end to the high-temperature end of the flow path 20 is called cascade arrangement. In this embodiment, an example was shown in which four types of

magnetocaloric materials

21a, 21b, 21c, and 21d are arranged in a cascade as shown in FIG. The number of types does not matter as long as they are provided in a cascade arrangement. However, as the number of types of magnetocaloric materials 21 provided in the flow path 20 increases, the temperature difference between one end and the other end of the flow path 20 can be increased. It can increase efficiency.

In addition, the magnetocaloric materials 21 are laid out in the flow path 20 so that adjacent magnetocaloric materials 21 of different types do not mix with each other due to the flow of the heat exchange fluid 9. However, when the heat exchange fluid 9 repeatedly reciprocates within the channel 20 for a long time, the magnetocaloric material 21 may be mixed in due to the flow of the heat exchange fluid 9. Therefore, in order to prevent the magnetocaloric materials 21 from mixing due to the flow of the heat exchange fluid 9, the mesh 13 may be provided to separate adjacent magnetocaloric materials 21 of different types.

FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed 10. As shown in FIG. 3, the magnetocaloric materials 21 arranged in a cascade in the flow path 20 are partitioned by a mesh 13 so that different types of magnetocaloric materials 21 do not mix. Note that the mesh 13 may be of any type as long as it is made of a material and has a shape that allows the heat exchange fluid 9 to pass through but does not allow the magnetocaloric material 21 to pass through. Moreover, the mesh 13 does not necessarily need to be provided in the flow path 20 when the magnetocaloric material 21 is provided in the flow path 20 without being mixed by the flow of the heat exchange fluid 9.

Furthermore, although not shown, the mesh 13 may be provided between the water pipe 7 and the flow path 20 at the low temperature end and high temperature end of the flow path 20. In this way, by providing the mesh 13 between the water pipe 7 and the flow path 20, it is possible to prevent the magnetocaloric material 21 from flowing out into the water pipe 7. Note that when the mesh 13 is provided between the water pipe 7 and the flow path 20 at the low temperature end and high temperature end of the flow path 20, for example, a spacer is provided between the flange 12 and the mesh 13 to fix the mesh 13. It is better to do this.

Here, when the magnetocaloric material 21 provided in the flow path 20 of the magnetocaloric material bed 10 is excited and the electron spins are aligned in the direction of the magnetic field, the magnetic entropy decreases and heat is emitted, thereby generating heat. On the other hand, when electron spins become disordered due to demagnetization, magnetic entropy increases and heat is absorbed. Therefore, the magnetocaloric material 21 is preferably a magnetic material that exhibits a high magnetocaloric effect at room temperature, such as a mixture of manganese, iron, phosphorus, and germanium, or a gadolinium-based material or alloy.

Next, the heat storage material 22 provided in the flow path 20 will be explained using FIGS. 2 to 7. FIG. 4 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material 21 provided in the channel 20 of the magnetocaloric material bed 10 and the phase transition temperature of the heat storage material 22 according to the first embodiment. FIG. 5 is a diagram showing a temperature change of the magnetocaloric material 21 at the other end side of the magnetocaloric material bed 10 according to the first embodiment. FIG. 6 is a sectional view taken along the line AA shown in FIG. 1 of a modification of the magnetocaloric material bed 10 according to the first embodiment. FIG. 7 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material 21 provided in the channel 20 of the magnetocaloric material bed 10 and the phase transition temperature of the heat storage material 22 according to the first embodiment.

As shown in FIGS. 2 and 3, the magnetocaloric material 21 is provided in the channel 20 of the magnetocaloric material bed 10 so that the Curie temperature increases from one end of the channel 20 to the other end. Further, a plurality of types of heat storage materials 22 are provided within the flow path 20.

The heat storage material 22 is provided in the flow path 20 such that the phase transition temperature increases in order from one end of the flow path 20 to the other end. Further, the heat storage material 22 provided on one end side has a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 provided on the one end side, and the heat storage material 22 provided on the other end side has a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 provided on the other end side. The phase transition temperature is lower than the Curie temperature of the magnetocaloric material 21. Here, the phase transition temperature is the temperature at which phase transition occurs.

This will be explained using FIGS. 2 and 4. As shown in FIG. 2, the magnetocaloric material 21 is provided with

magnetocaloric materials

21a, 21b, 21c, and 21d in order from one end of the flow path 20. The heat storage material 22 is provided with a heat storage material 22b on one end side and a heat storage material 22c on the other end side.

Further, FIG. 4 is a graph showing the relationship between the Curie temperature of the magnetocaloric material 21 and the phase transition temperature of the heat storage material 22. Here, the operating environment temperature shown in FIG. 4 refers to the temperature of the environment in which the magnetocaloric material bed 10 is installed. For example, when the magnetocaloric material bed 10 is installed outside, it refers to the temperature of the outside air, and when it is installed indoors, it refers to the indoor temperature.

As shown in FIG. 4, the heat storage material 22b provided on one end side has a phase transition temperature higher than the Curie temperature of the

magnetocaloric materials

21a and 21b provided on the one end side. On the other hand, the heat storage material 22c provided on the other end side has a phase transition temperature lower than the Curie temperature of the

magnetocaloric materials

21c and 21d provided on the other end side. Further, the phase transition temperature of the heat storage material 22, that is, the heat storage material 22c provided on the other end side of the flow path 20 is higher than the operating environment temperature, and the phase transition temperature of the heat storage material 22, that is, the heat storage material 22b provided on the one end side is higher than the operating environment temperature. Lower than the operating environment temperature. Furthermore, the phase transition temperature of the heat storage material 22c provided on the other end side of the flow path 20 is higher than the phase transition temperature of the heat storage material 22b provided on the one end side.

FIG. 5 is a diagram showing the temperature change of the magnetocaloric material 21 on the other end side of the flow path 20. The vertical axis shows temperature, and the horizontal axis shows time. Thick solid lines and dotted lines show temperature changes with heat storage material 22 in the flow path 20, and thin solid lines and dotted lines show temperature changes without heat storage material 22 in the flow path 20. In addition, K1 is the phase transition temperature, K2 is the Curie temperature, t0 is when the magnetic refrigeration system 1 is stopped, t1 is when the magnetic refrigeration system 1 is restarted, and T1 and T2 are the temperature from the time of restart until the Curie temperature is reached. refers to time. Note that the solid line shows the temperature change of the magnetocaloric material 21 when the magnetic refrigeration system 1 is restarted, and the dotted line shows the temperature change after the magnetic refrigeration system 1 is stopped without restarting.

As shown in FIG. 5, since the Curie temperature K2 of the magnetocaloric material 21 is higher than the operating environment temperature, the temperature of the magnetocaloric material 21 decreases due to heat radiation to the outside immediately after the operation is stopped. On the other hand, when the heat storage material 22 is provided in the flow path 20, heat transfers from the heat storage material 22 to the magnetocaloric material 21 after the operation is stopped. In comparison, the temperature change of the magnetocaloric material 21 is gradual. That is, the temperature change of the magnetocaloric material 21 after the magnetic refrigeration device 1 is stopped varies greatly depending on whether or not the heat storage material 22 is provided in the flow path 20, and the Curie temperature K2 of the magnetocaloric material 21 after restarting The arrival time is shorter for the magnetocaloric material 21 in which the heat storage material 22 is provided in the flow path 20 than in the magnetocaloric material 21 in which the heat storage material 22 is not provided in the flow path 20 (T2<T1) . Although the explanation is omitted, this is the same on the low temperature end side, and the magnetocaloric material 21 where the heat storage material 22 is provided in the flow path 20 is higher than the magnetocaloric material 21 where the heat storage material 22 is not provided in the flow path 20. Material 21 takes a shorter time to reach the Curie temperature after the magnetic refrigeration device 1 is restarted.

As described above, in the magnetocaloric material bed 10, the heat storage material 22 provided on one end side has a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 provided on the one end side, and the heat storage material provided on the other end side 22 is a heat storage material 22 whose phase transition temperature is lower than the Curie temperature of the magnetocaloric material 21 provided on the other end side. Changes can be made smaller. Furthermore, after the magnetic refrigeration device 1 is restarted, the temperature of the magnetocaloric material 21 can quickly reach the Curie temperature.

Further, FIG. 6 is an example of a magnetocaloric material bed 10 in which four types of

heat storage materials

22a, 22b, 22c, and 22d having different phase transition temperatures are provided in the flow path 20. As shown in FIG. 6, the heat storage materials 22 are provided in the flow path 20 in correspondence to the different types of magnetocaloric materials 21. That is, on one end side of the flow path 20, a heat storage material 22a is provided in the flow path 20 in which the magnetocaloric material 21a is provided, and a heat storage material 22b is provided in the flow path 20 in which the magnetocaloric material 21b is provided. It is being Similarly, on the other end side of the channel 20, a heat storage material 22c is provided in the channel 20 in which the magnetocaloric material 21c is provided, and a heat storage material 22d is provided in the channel 20 in which the magnetocaloric material 21d is provided. is provided. In this way, within the flow path 20, the magnetocaloric material 21 and the heat storage material 22 are arranged as a pair.

Further, FIG. 7 shows the relationship between the Curie temperature of the magnetocaloric material 21 provided in the flow path 20 and the phase transition temperature of the heat storage material 22. On one end side of the flow path 20, a heat storage material 22a having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21a is provided in the flow path 20 in which the magnetocaloric material 21a is provided, and the Curie temperature of the magnetocaloric material 21b is A heat storage material 22b having a phase transition temperature higher than the temperature is provided in the flow path 20 in which the magnetocaloric material 21b is provided. On the other hand, on the other end side of the flow path 20, a heat storage material 22c having a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21c is provided in the flow path 20 in which the magnetocaloric material 21c is provided. A heat storage material 22d having a phase transition temperature lower than the Curie temperature of the heat storage material 21d is provided in the flow path 20 in which the magnetocaloric material 21d is provided. Further, the phase transition temperature of the heat storage materials 22a and 22b provided at one end of the flow path 20 is lower than the operating environment temperature, and the phase transition temperature of the

heat storage materials

22c and 22d provided at the other end of the flow path 20 is lower than the operating environment temperature. Higher than the operating environment temperature. In this way, the heat storage material 22 is provided in the flow path 20 corresponding to each magnetocaloric material 21.

As described above, the plurality of types of heat storage materials 22 provided in the flow path 20 are arranged in the flow path 20 such that the phase transition temperature increases in order from one end to the other end corresponding to each magnetocaloric material 21. It is provided. In addition, the heat storage material 22 provided in the flow path 20 has a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 provided at one end, and the heat storage material 22 provided at one end has a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 provided at the other end. The provided heat storage material 22 has a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21 provided on the other end side. By providing the heat storage material 22 in a manner corresponding to the type of the magnetocaloric material 21 provided in the flow path 20, the magnetic refrigeration system 1 equipped with the magnetocaloric material bed 10 shown in FIG. After the refrigeration device 1 is stopped, the temperature change in the magnetocaloric material 21 can be reduced. Furthermore, after the magnetic refrigeration device 1 is restarted, the temperature of the magnetocaloric material 21 can quickly reach the Curie temperature. This improves operating efficiency and saves energy.

Here, it is preferable to use a latent heat storage material for the heat storage material 22 provided in the flow path 20. For example, saturated hydrocarbons, fatty acids such as stearic acid or palmitic acid, low melting point metals such as potassium and sodium or their alloys, sugar alcohols such as erythritol and threitol, sodium acetate trihydrate and sodium thiosulfate pentahydrate. Hydrated salts such as, molten salts such as calcium chloride or lithium chloride, clathrate hydrates such as tetrabutylammonium bromide, and water can be used. These latent heat storage materials can store a large amount of heat by absorbing and releasing large amounts of latent heat during phase transition from solid to liquid and from liquid to solid.

On the other hand, when these latent heat storage materials are used as the heat storage material 22, they become liquid at temperatures above their melting point, so if the latent heat storage materials are directly provided as the heat storage material 22 in the channel 20 of the magnetocaloric material bed 10, the temperature will rise and the temperature will increase. The heat storage material 22 will melt. After the melted heat storage material 22 moves through the flow path 20 together with the heat exchange fluid 9, the temperature decreases and solidifies, potentially clogging the water pipe 7, resulting in a decrease in refrigeration performance due to a decrease in flow rate, and a risk of failure. It becomes a factor.

Therefore, in order to prevent the heat storage material 22 from melting and moving within the flow path 20, the heat storage material 22 is preferably covered with a capsule 23 as shown in FIG. Here, the capsule 23 is made of, for example, melamine, acrylic, urethane, silica, or the like. In this way, by covering the heat storage material 22 with the capsule 23, when the heat storage material 22 melts and becomes liquid, it will not mix with the heat exchange fluid 9, so it will solidify and block the water pipe 7. prevent that.

Further, as the heat storage material 22, it is preferable to use a latent heat storage material such as vanadium oxide, which stores heat during phase transition from solid to solid. When such a latent heat storage material is provided as the heat storage material 22 in the flow path 20, the heat storage material 22 does not melt and mix with the heat exchange fluid 9, so there is no need to cover it with the capsule 23, and the amount of heat storage per volume is reduced. can be made larger.

Next, the operating principle of the magnetic refrigeration device 1 will be explained.

When the magnetocaloric material 21 provided in the channel 20 of the magnetocaloric material bed 10 is excited by the magnetic field modulation device 6, the magnetocaloric material 21 generates heat due to the magnetocaloric effect. The heat of the magnetocaloric material 21 is thermally transferred to the heat exchange fluid 9 adjacent to the magnetocaloric material 21 .

By the pump 5, the heat exchange fluid 9 in the water pipe 7, the low temperature side heat exchanger 2 and the magnetocaloric material bed 10 is transferred from the low temperature side heat exchanger 2 side to the high temperature side heat exchanger 3 via the magnetocaloric material bed 10. By being transported to the side, the heat of the magnetocaloric material 21 is carried to the hot side heat exchanger 3 by the heat exchange fluid 9. The heat exchange fluid 9 carried to the high-temperature side heat exchanger 3 is cooled by exchanging heat with air, and its temperature decreases.

Next, when the magnetocaloric material 21 provided in the flow path 20 of the magnetocaloric material bed 10 is demagnetized by the magnetic field modulation device 6, the magnetocaloric material 21 generates cold heat due to the magnetocaloric effect. The cold heat of the magnetocaloric material 21 is thermally transferred to the heat exchange fluid 9 adjacent to the magnetocaloric material 21 .

The pump 5 moves the heat exchange fluid 9 in the water pipe 7, the high temperature side heat exchanger 3 and the magnetocaloric material bed 10 from the high temperature side heat exchanger 3 side to the low temperature side heat exchanger 2 via the magnetocaloric material bed 10. By being transported to the side, the cold heat of the magnetocaloric material 21 is carried to the low temperature side heat exchanger 2 by the heat exchange fluid 9. The heat exchange fluid 9 carried to the low-temperature side heat exchanger 2 exchanges heat with the medium to be cooled flowing through the medium to be cooled channel, and its temperature increases.

In this way, by repeating the above steps, a magnetic refrigeration cycle is realized that transports cold heat to the low-temperature side heat exchanger 2 and transports warm heat to the high-temperature side heat exchanger 3.

As described above, the magnetocaloric material bed 10 shown in this embodiment includes a plurality of types of magnetocaloric materials 21 provided in the flow path 20 so that the Curie temperature increases in order from one end to the other end, and a magnetocaloric material bed 10 of the present embodiment. A plurality of types of heat storage materials 22 are provided in the flow path 20 so that the phase transition temperature becomes higher in order. In the flow path 20, a heat storage material 22 having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 is provided in the flow path 20 in which the magnetocaloric material 21 having a Curie temperature lower than the operating environment temperature is provided. A heat storage material 22 having a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21 is provided in the channel 20 in which the magnetocaloric material 21 is provided with the magnetocaloric material 21 having a Curie temperature higher than the operating environment temperature. With this configuration, each magnetocaloric material 21 can quickly reach the Curie temperature when starting up the magnetic refrigeration device 1, such as when starting up the device, such as when restarting the device, and the operating efficiency is improved.

Note that in this embodiment, regarding the magnetocaloric material 21 and heat storage material 22 provided in the flow path 20 of the magnetocaloric material bed 10, the magnetocaloric material 21 is provided in the flow path 20 in a larger amount than the heat storage material 22. A magnetocaloric material bed 10 is shown. However, the ratio of the magnetocaloric material 21 and the heat storage material 22 is not particularly limited, and may be changed as appropriate depending on the required specifications. For example, when it is required to increase the temperature difference between one end and the other end of the flow path 20, the proportion of the heat storage material 22 is decreased and the proportion of the magnetocaloric material 21 is increased. On the other hand, when the magnetic refrigeration apparatus 1 is frequently stopped and restarted, it is required that the temperature of the magnetocaloric material 21 quickly reach the Curie temperature. In such a case, the ratio occupied by the heat storage material 22 is made higher than that of the magnetocaloric material bed 10 when a large temperature difference is required. In this way, by changing the proportion of the heat storage material 22 in the flow path 20 of the magnetocaloric material bed 10 depending on the intended use, it is possible to obtain a magnetocaloric material bed 10 suitable for the required specifications.

In addition, in the present embodiment, a magnetocaloric material bed 10 in which four types of

magnetocaloric materials

21a, 21b, 21c, and 21d are provided in the flow path 20 so that the Curie temperature increases in order from one end to the other end. showed that. The magnetocaloric material bed 10 has a configuration in which two types of

magnetocaloric materials

21a and 21b are provided in the channel 20 at one end and two types are provided at the other end, that is,

magnetocaloric materials

21a and 21b are provided at one end, and

magnetocaloric materials

21c and 21d are provided at the other end. However, the magnetocaloric material bed 10 in which the magnetocaloric material 21 is provided so as to straddle one end side and the other end side will also be described.

The magnetocaloric material bed 10 in which the magnetocaloric material 21 is provided so as to straddle one end side and the other end side will be explained using FIGS. 9 to 12. FIG. 9 is a sectional view taken along the line AA shown in FIG. 1 of the magnetocaloric material bed 10 in which the magnetocaloric material 21 is provided so as to straddle one end side and the other end side. FIG. 10 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material 21 provided in the flow path 20 and the phase transition temperature of the heat storage material 22. FIG. 11 is a sectional view taken along the line AA shown in FIG. 1 of the magnetocaloric material bed 10 in which the magnetocaloric material 21 is provided so as to straddle one end side and the other end side. FIG. 12 is a diagram showing the relationship between the Curie temperature of the magnetocaloric material 21 provided in the flow path 20 and the phase transition temperature of the heat storage material 22.

As shown in FIG. 9, a magnetocaloric material 21b is provided in the flow path 20 spanning from one end side to the other end side. In this case, a heat storage material 22b is provided in the flow path 20 in which the magnetocaloric material 21b is provided. That is, as shown in FIG. 10, when the magnetocaloric material 21b whose Curie temperature is lower than the operating environment temperature is provided so as to straddle both one end side and the other end side, the magnetocaloric material 21b on the one end side A heat storage material 22b having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21b is provided in the flow path 20 in which the material 21b is provided. On the other hand, a heat storage material 22b is also provided in the channel 20 in which the magnetocaloric material 21b is provided at the other end. In other words, in the flow path 20 in which the magnetocaloric material 21 having a Curie temperature lower than the operating environment temperature is provided on both one end side and the other end side, the phase transition temperature is higher than the Curie temperature of the magnetocaloric material 21. A heat storage material 22 is provided.

As shown in FIG. 11, a magnetocaloric material 21c is provided in the flow path 20 spanning from one end side to the other end side. In this case, a heat storage material 22c is provided in the channel 20 in which the magnetocaloric material 21c is provided. That is, as shown in FIG. 12, when the magnetocaloric material 21c whose Curie temperature is lower than the operating environment temperature is provided so as to straddle both one end side and the other end side, the magnetic field at the other end side A heat storage material 22c having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21c is provided in the flow path 20 in which the caloric material 21c is provided. On the other hand, a heat storage material 22c is also provided in the channel 20 in which the magnetocaloric material 21c is provided at one end. In other words, in the channel 20 in which the magnetocaloric material 21 is provided at both one end and the other end thereof, the magnetocaloric material 21 has a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21. A heat storage material 22 is provided.

From the above, when the magnetocaloric material bed 10 has a structure in which the magnetocaloric material 21 is provided in the channel 20 so as to span both one end side and the other end side, In the channel 20 in which the magnetocaloric material 21 is provided, different types of heat storage materials 22 are not provided at one end and the other end, but the same type of heat storage materials 22 are provided.

Embodiment 2.
This embodiment will be explained using FIG. 13. FIG. 13 is a sectional view of a heat storage material covered with a magnetocaloric material capsule of a magnetocaloric material bed according to the second embodiment.

In the first embodiment, the heat storage material 22 is shown covered with a capsule 23 so that it does not melt, mix with the heat exchange fluid 9, and move within the flow path 20. In this embodiment, a magnetocaloric material bed 10a is shown in which a heat storage material 22 is covered with a magnetocaloric material capsule 24 formed of a magnetocaloric material 21 and provided in a flow path 20 of the magnetocaloric material bed 10a. The other configurations are the same as those in Embodiment 1, and the same components as in Embodiment 1 are given the same numbers and their explanations will be omitted.

The magnetocaloric material bed 10a according to the present embodiment includes a plurality of types of magnetocaloric materials 21 provided in a flow path 20 such that the Curie temperature increases in order from one end to the other end, and a phase transition from one end to the other end. A plurality of types of heat storage materials 22 are provided in the flow path 20 so that the temperature increases in sequence. In the flow path 20, a heat storage material 22 having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 is provided in the flow path 20 in which the magnetocaloric material 21 having a Curie temperature lower than the operating environment temperature is provided. A heat storage material 22 having a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21 is provided in the channel 20 in which the magnetocaloric material 21 is provided with the magnetocaloric material 21 having a Curie temperature higher than the operating environment temperature. Thereby, after the magnetic refrigeration device 1 is stopped, the temperature change of the magnetocaloric material 21 can be reduced. Furthermore, after the magnetic refrigeration device 1 is restarted, the temperature of the magnetocaloric material 21 can quickly reach the Curie temperature.

Furthermore, the heat storage material 22 according to this embodiment is covered with a magnetocaloric material capsule 24 formed of the magnetocaloric material 21, as shown in FIG. Note that the magnetocaloric material 21 that forms the magnetocaloric material capsule 24 is a magnetocaloric material 21 that is adjacent to the heat storage material 22 in the flow path 20 . For example, in the case of the heat storage material 22a shown in FIG. 6, the magnetocaloric material 21a adjacent to the heat storage material 22a is used as the magnetocaloric material 21 forming the magnetocaloric material capsule 24 that covers the heat storage material 22a.

As described above, in the magnetocaloric material bed 10a according to the present embodiment, the heat storage material 22 is covered with the magnetocaloric material capsule 24 formed of the magnetocaloric material 21, and is provided in the flow path 20 of the magnetocaloric material bed 10a. ing. With this configuration, it becomes unnecessary to use a capsule made of a material different from that of the magnetocaloric material 21, and the volume within the channel 20 of the magnetocaloric material bed 10a can be effectively utilized. Therefore, the amount of magnetocaloric material 21 can be increased, and a high magnetic refrigeration effect can be obtained.

Embodiment 3.
This embodiment will be explained using FIG. 14. FIG. 14 is a sectional view of a magnetocaloric material bed according to the third embodiment.

Embodiment 1 showed the magnetocaloric material bed 10 in which the heat storage material 22 was provided in the flow path 20 of the magnetocaloric material bed 10. In this embodiment, a magnetocaloric material bed 10b is shown in which a heat storage material 22 is provided on a bed wall 11a that forms a flow path 20a. The other configurations are the same as those in Embodiment 1, and the same configurations as in Embodiment 1 are given the same numbers and descriptions thereof will be omitted.

The magnetocaloric material bed 10b according to the present embodiment has a plurality of types of magnetocaloric materials 21 provided in the flow path 20a such that the Curie temperature increases in order from one end to the other end, and a phase transition from one end to the other end. A plurality of types of heat storage materials 22 are provided in the flow path 20a so that the temperature increases in sequence. In the flow path 20a, a heat storage material 22 having a phase transition temperature higher than the Curie temperature of the magnetocaloric material 21 is provided in the flow path 20a in which the magnetocaloric material 21 whose Curie temperature is lower than the operating environment temperature is provided. A heat storage material 22 having a phase transition temperature lower than the Curie temperature of the magnetocaloric material 21 is provided in the flow path 20a in which the magnetocaloric material 21 is provided with the magnetocaloric material 21 having a Curie temperature higher than the operating environment temperature. Thereby, after the magnetic refrigeration device 1 is stopped, the temperature change of the magnetocaloric material 21 can be reduced. Furthermore, after the magnetic refrigeration system 1 is restarted, the temperature of the magnetocaloric material 21 can quickly reach the Curie temperature.

Furthermore, as shown in FIG. 14, a heat storage material 22 is provided on the bed wall 11a of the flow path 20a. As an example, in FIG. 14, four types of

heat storage materials

22a, 22b, 22c, and 22d are arranged in the flow path 20a in the order of

heat storage materials

22a, 22b, 22c, and 22d from the low temperature end to the high temperature end. It is provided on the bed wall 11a of the bed 20a. That is, the position where the heat storage material 22 is provided differs from the magnetocaloric material bed 10 shown in Embodiment 1.

By providing the heat storage material 22 on the bed wall 11a of the flow path 20a in this manner, the heat capacity within the flow path 20a of the magnetocaloric material bed 10b can be increased. In addition, after the magnetic refrigeration system 1 is stopped, rapid temperature changes in the magnetocaloric material 21 can be suppressed, and the time required for the magnetocaloric material 21 to reach the Curie temperature when restarted can be shortened. Capacity starts up faster, operating efficiency improves, and energy is saved.

1 magnetic refrigeration device, 2 low temperature side heat exchanger, 3 high temperature side heat exchanger, 4 fan, 5 pump, 6 magnetic field modulator, 7 water tube, 9 heat exchange fluid, 10, 10a, 10b magnetocaloric material bed, 11, 11a bed wall, 12 flange, 13 mesh, 20, 20a flow path, 21 magnetocaloric material, 22 heat storage material, 23 capsule, 24 magnetocaloric material capsule

Claims

a flow path through which a heat exchange fluid flows back and forth between one end and the other end;
a plurality of types of magnetocaloric materials provided in the flow path so as to exchange heat with the heat exchange fluid so that the Curie temperature increases in order from the one end to the other end;
a plurality of types of heat storage materials provided in the flow path so that the phase transition temperature increases in order from the one end to the other end;
Equipped with
The heat storage material having a phase transition temperature higher than the Curie temperature of the magnetocaloric material is provided in the flow path in which the magnetocaloric material having the Curie temperature lower than the operating environment temperature is provided, and the operating environment temperature The heat storage material having a phase transition temperature lower than the Curie temperature of the magnetocaloric material is provided in the flow path in which the magnetocaloric material has a Curie temperature higher than that of the magnetocaloric material. Calorie material bed.
The heat storage material provided on one end side has the phase transition temperature higher than the Curie temperature of the magnetocaloric material provided on the one end side, and the heat storage material provided on the other end side has a higher phase transition temperature than the Curie temperature of the magnetocaloric material provided on the one end side. 2. The magnetocaloric material bed of claim 1, wherein the phase transition temperature is lower than the Curie temperature of the magnetocaloric material provided.
The magnetocaloric material bed according to claim 1 or 2, wherein the heat storage material is provided corresponding to each of the magnetocaloric materials.
The magnetocaloric material bed according to any one of claims 1 to 3, wherein the heat storage material is provided within the flow path.
The magnetocaloric material bed according to any one of claims 1 to 4, wherein the heat storage material is provided on a bed wall that forms the flow path.
The magnetocaloric material bed according to any one of claims 1 to 5, wherein the heat storage material is covered with a capsule.
The magnetocaloric material bed according to any one of claims 1 to 6, wherein the heat storage material is covered with a magnetocaloric material capsule formed of the magnetocaloric material.
The magnetocaloric material bed according to any one of claims 1 to 7, wherein the heat storage material is a latent heat storage material that stores heat during phase transition from solid to solid.
A bed of magnetocaloric material according to any one of claims 1 to 8,
a magnetic field modulation device configured to be able to vary the magnetic field applied to the magnetocaloric material bed having a flow path in which the magnetocaloric material is provided;
a high temperature side heat exchanger connected to the magnetocaloric material bed;
a cold side heat exchanger connected to the magnetocaloric material bed opposite the hot side heat exchanger;
a pump configured to be able to transport a heat exchange fluid back and forth between the high temperature side heat exchanger and the low temperature side heat exchanger via the magnetocaloric material bed;
A magnetic refrigeration device equipped with.