Magnetic refrigeration system

Abstract

[Problem] To improve capacity in a magnetic refrigeration system that utilizes a magnetic calorific material over cases where the magnetic refrigeration system is configured from a plurality of units including the magnetic calorific material. [Solution] A magnetic refrigeration system comprises: a magnetic refrigeration material part that includes a magnetic refrigeration material through which a fluid passes; a magnetic field application circuit that applies a magnetic field to the magnetic refrigeration material part to increase the temperature thereof; an inlet header through which the fluid flows into the magnetic refrigeration material part; an outlet header through which the fluid flows out of the magnetic refrigeration material part; and a drive unit that moves the magnetic refrigeration material part relative to the magnetic field application circuit, the inlet header, and the outlet header. The inlet header includes a high-temperature-side inlet header and a low-temperature-side inlet header. The outlet header includes a high-temperature-side outlet header and a low-temperature-side outlet header. The magnetic refrigeration material part is configured from a continuous body that includes an excitation part to which a magnetic field is applied by the magnetic field application circuit and a non-excitation part to which the magnetic field is not applied. The fluid flows from the low-temperature-side inlet header to the high-temperature-side outlet header in the excitation part, and flows from the high-temperature-side inlet header to the low-temperature-side outlet header in the non-excitation part.

Description

Magnetic refrigeration system

[0001] The present disclosure relates to a magnetic refrigeration system.

[0002] Patent Document 1 describes a magnetic refrigerator including a plurality of magnetic heat exchange units including a magnetic calorimetric material through which a heat transfer fluid flows, a rotating plate provided at predetermined intervals along the circumferential direction for each of the magnetic heat exchange units, and a magnet disposed between the upper and lower surfaces of the rotating plate for applying a magnetic field to raise the temperature when the magnetic heat exchange unit passes through.

[0003] Japanese Patent Translation of PCT No. 2009-515135

[0004] A magnetic refrigeration system using an AMR (Active Magnetic Refrigeration) cycle that generates heat and cold by repeatedly exciting and demagnetizing a magnetic refrigeration material is known. In Patent Document 1, in order to realize the AMR cycle, a plurality of magnetic heat exchange units (hereinafter referred to as units) including a magnetic refrigeration material are provided in the circumferential direction of a rotating plate, and the rotation of the rotating plate repeatedly causes excitation and demagnetization of the units. When using a plurality of units, it is necessary to flow a heat transfer fluid in an excited state in which a magnetic field is applied to the entire area of the unit and in a non-excited state in which no magnetic field is applied to the unit. Therefore, a waiting time for becoming an excited state or a non-excited state occurs, and the performance of the magnetic refrigeration system deteriorates. The present disclosure aims to improve the performance in a magnetic refrigeration system using a magnetic refrigeration material as compared with a case where the system is composed of a plurality of units including the magnetic refrigeration material.

[0005] The magnetic refrigeration system of this disclosure comprises a magnetic refrigeration material section containing a magnetic refrigeration material through which a fluid passes; a magnetic field application circuit that applies a magnetic field to the magnetic refrigeration material section to raise its temperature; an inlet header through which the fluid flows into the magnetic refrigeration material section; an outlet header through which the fluid flows out of the magnetic refrigeration material section; and a drive unit that moves the magnetic refrigeration material section relative to the magnetic field application circuit, the inlet header, and the outlet header. The inlet header includes a high-temperature side inlet header and a low-temperature side inlet header, and the outlet header includes a high-temperature side outlet header and a low-temperature side outlet header. The magnetic refrigeration material section is composed of a continuum including an excitation section to which a magnetic field is applied by the magnetic field application circuit and an unexcited section to which no magnetic field is applied. The fluid flows from the low-temperature side inlet header to the high-temperature side outlet header in the excitation section and from the high-temperature side inlet header to the low-temperature side outlet header in the unexcited section. In this case, the capacity can be improved compared to a magnetic refrigeration system using a magnetic refrigeration material that is composed of multiple units including the magnetic refrigeration material. Here, the magnetic refrigeration material section has a pressure loss in the direction of fluid inflow from the inlet header that is smaller than the pressure loss in the direction perpendicular to the direction of fluid inflow from the inlet header. In this case, the fluid flow can be properly maintained. Also, the magnetic refrigeration material section has a density of the magnetic refrigeration material in the direction of fluid inflow from the inlet header that is smaller than the density of the magnetic refrigeration material in the direction perpendicular to the direction of fluid inflow from the inlet header. In this case, the fluid flow can be properly maintained. Also, the magnetic refrigeration material section has a pressure loss when the fluid flows from the high-temperature side inlet header to the low-temperature side outlet header that is smaller than the pressure loss when the fluid flows from the high-temperature side inlet header to the high-temperature side outlet header. In this case, the fluid flow from the high-temperature side inlet header to the high-temperature side outlet header can be suppressed. Also, the magnetic refrigeration material section has a distance from the center of the high-temperature side inlet header to the center of the low-temperature side outlet header that is shorter than the distance from the center of the high-temperature side inlet header to the center of the high-temperature side outlet header. In this case, it is possible to suppress the flow of fluid from the high-temperature side inlet header to the high-temperature side outlet header.Furthermore, the magnetic refrigeration material section has a pressure loss when the fluid flows from the low-temperature side inlet header to the high-temperature side outlet header that is smaller than the pressure loss when the fluid flows from the low-temperature side inlet header to the low-temperature side outlet header. In this case, the flow of fluid from the low-temperature side inlet header to the low-temperature side outlet header can be suppressed. The magnetic refrigeration material section also includes guide members that suppress the flow of fluid from the high-temperature side inlet header to the high-temperature side outlet header and the flow of fluid from the low-temperature side inlet header to the low-temperature side outlet header. In this case, the fluid flow can be properly maintained. The magnetic refrigeration material section also consists of a single container containing the magnetic refrigeration material. In this case, the fluid can be continuously supplied to the magnetic refrigeration material section. The fluid flows continuously from the high-temperature side inlet header to the low-temperature side outlet header and from the low-temperature side inlet header to the high-temperature side outlet header. In this case, the capacity can be improved compared to a magnetic refrigeration system using magnetic refrigeration material that is composed of multiple units including magnetic refrigeration material. The magnetic refrigeration material section is also disc-shaped and rotates by the drive unit. In this case, the fluid can be continuously supplied to the magnetic refrigeration material section. Furthermore, the magnetic refrigeration system of this disclosure includes covers fixed to the inlet header and the outlet header to prevent leakage of the fluid from the magnetic refrigeration material section. In this case, leakage of the fluid from the magnetic refrigeration material section can be suppressed. In addition, the magnetic refrigeration material section is made up of laminated materials with different temperature characteristics. In this case, the capacity can be improved compared to when materials with the same temperature characteristics are used. Furthermore, the inlet header and the outlet header are provided between the magnetic field application circuit and the magnetic refrigeration material section. In this case, the heat-transporting fluid can be flowed uniformly, and the capacity can be improved compared to when the system is composed of multiple units including the magnetic refrigeration material. Furthermore, the inlet header and the outlet header are provided before and after the magnetic refrigeration material section in the direction of movement relative to the magnetic field application circuit. In this case, the capacity can be improved in a magnetic refrigeration system using magnetic refrigeration material compared to when the system is composed of multiple units including the magnetic refrigeration material.Furthermore, the inlet header and outlet header are provided at one radial end and the other end of the disc-shaped magnetic refrigeration material section. In this case, the magnetic flux density can be increased, and the capacity can be improved compared to when the system is composed of multiple units including the magnetic refrigeration material.

[0006] This figure shows an example configuration of a magnetic refrigeration system according to this embodiment. This figure shows an example configuration of a heat source block according to this embodiment. This figure shows a cross-section of the heat source block shown in Figure 2, cut along the dashed line III, unfolded into a plane. This figure shows the length of the flow path in the magnetic refrigeration material section. This figure shows the relationship between the application of a magnetic field to the magnetic refrigeration material section and the flow of the heat transport fluid. (a) shows an example where a heat source block consisting of multiple units is used, as shown in Figure 6. (b) shows an example where a heat source block according to this embodiment is used. This figure shows an example configuration of a heat source block when the heat source block consists of multiple units. This figure shows an example configuration of a heat source block when four sets of magnets are installed. This figure shows an example configuration of a heat source block according to the first modification. This figure shows a cross-section of the heat source block shown in Figure 8, cut along the dashed line IX, unfolded into a plane. This figure shows the length of the flow path in the magnetic refrigeration material section. This figure shows an example configuration of a heat source block according to the second modification. This figure shows a part of the heat source block according to the second modification viewed from the top side. This figure shows a cross-section of the magnetic refrigeration material section when materials with different temperature characteristics are laminated together.

[0007] The embodiments will be described in detail below with reference to the attached drawings. <Configuration of the Magnetic Refrigeration System> Figure 1 is a diagram showing an example configuration of the magnetic refrigeration system 1 according to this embodiment. The magnetic refrigeration system 1 comprises a heat source block 10, a low-temperature side circuit 60, and a high-temperature side circuit 70. The heat source block 10 comprises a low-temperature side inlet header 11, a low-temperature side outlet header 12, a high-temperature side inlet header 13, a high-temperature side outlet header 14, and a magnet 16. The low-temperature side circuit 60 comprises a low-temperature side heat exchanger 61 and low-temperature side piping 62. The high-temperature side circuit 70 comprises a high-temperature side heat exchanger 71, high-temperature side piping 72, and a pump 73. In the magnetic refrigeration system 1, a heat-transporting fluid circulates through the heat source block 10, the low-temperature side circuit 60, and the high-temperature side circuit 70. The heat-transporting fluid is an example of a fluid.

[0008] The heat source block 10 includes a magnetic refrigeration material. The magnetic refrigeration material has a magnetic refrigeration effect in which its temperature reversibly changes when a magnetic field is applied and when the applied magnetic field is removed. The heat source block 10 has a magnetic field application circuit that applies a magnetic field to the magnetic refrigeration material. The magnetic refrigeration material is repeatedly energized and demagnetized to generate heat and cold. The heat transfer fluid exchanges heat with the magnetic refrigeration material by coming into contact with it. The heat generated in the heat source block 10 is transferred to the high-temperature side circuit 70 by the heat transfer fluid, and the cold generated in the heat source block 10 is transferred to the low-temperature side circuit 60.

[0009] The heat source block 10 includes an excitation section to which a magnetic field is applied by a magnetic field application circuit, and a non-excitation section to which no magnetic field is applied. In the excitation section, the temperature of the magnetic refrigeration material rises when a magnetic field is applied, and in the non-excitation section, the temperature decreases when the magnetic field is removed. The configuration of the heat source block 10 will be described in detail later.

[0010] Figure 1 illustrates the flow path of the heat transfer fluid. The heat transfer fluid, which flows from the low-temperature side inlet header 11 to the heat source block 10, is heated in the excitation section and flows out from the high-temperature side outlet header 14, entering the high-temperature side heat exchanger 71 via the high-temperature side piping 72. The high-temperature side heat exchanger 71 exchanges heat with the heat transfer fluid, cooling it. The cooled heat transfer fluid flows back into the heat source block 10 from the high-temperature side inlet header 13 via the high-temperature side piping 72. The heat transfer fluid that flows into the heat source block 10 is cooled in the non-excitation section and flows out from the low-temperature side outlet header 12, entering the low-temperature side heat exchanger 61 via the low-temperature side piping 62. The low-temperature side heat exchanger 61 exchanges heat with the heat transfer fluid, heating it. The heated heat transfer fluid flows back into the heat source block 10 from the low-temperature side inlet header 11 via the low-temperature side piping 62. A pump 73 provided in the high-temperature side piping 72 circulates the heat transfer fluid.

[0011] <Configuration of Heat Source Block 10> The configuration of the heat source block 10 will be explained using Figures 2 and 3. Figure 2 is a diagram showing an example of the configuration of the heat source block 10 according to this embodiment. Figure 3 is a diagram showing the cross-section of the heat source block 10 shown in Figure 2 cut along the dashed line III, unfolded into a plane. Figure 3 also shows the low-temperature side circuit 60 and the high-temperature side circuit 70 together.

[0012] The heat source block 10 comprises a magnetic refrigeration material section 15 and a magnet 16. The magnetic refrigeration material section 15 includes a magnetic refrigeration material through which a heat-transporting fluid passes. The magnet 16 applies a magnetic field to the magnetic refrigeration material section 15. The magnet 16 is an example of a magnetic field application circuit. The heat source block 10 also comprises a low-temperature side inlet header 11 and a high-temperature side inlet header 13 through which the heat-transporting fluid flows into the magnetic refrigeration material section 15. The heat source block 10 also comprises a low-temperature side outlet header 12 and a high-temperature side outlet header 14 through which the heat-transporting fluid flows out of the magnetic refrigeration material section 15. The low-temperature side inlet header 11 and the high-temperature side inlet header 13 are sometimes called inlet headers, and the low-temperature side outlet header 12 and the high-temperature side outlet header 14 are sometimes called outlet headers. The dashed line III is the arc passing through the radial center of the magnetic refrigeration material section 15, from the center of the low-temperature side inlet header 11 to the center of the adjacent low-temperature side inlet header 11, with the low-temperature side outlet header 12 in between.

[0013] Furthermore, the heat source block 10 is fixed to the inlet header and outlet header and includes a cover 17 that prevents heat transfer fluid from leaking out of the magnetic refrigeration material section 15 (see Figure 3). For simplicity, the cover 17 is not shown in Figure 2. The heat source block 10 also includes a guide member 18 that controls the flow of heat transfer fluid inside the magnetic refrigeration material section 15. The heat source block 10 also includes a sealing member 19 that prevents heat transfer fluid from leaking out of the joint between the inlet header and outlet header and the cover 17. The cover 17 is joined and fixed to the inlet header and outlet header via the sealing member 19. The sealing member 19 may also be configured to fill the gap between the magnetic refrigeration material section 15 and the cover 17. This prevents fluid from flowing from the inlet header through the gap between the magnetic refrigeration material section 15 and the cover 17 to an unsuitable outlet header, thereby suppressing a decrease in capacity.

[0014] The magnetic refrigeration material section 15 is, for example, a porous body in which magnetic refrigeration material is laminated. The magnetic refrigeration material section 15 moves relative to the magnet 16, cover 17, inlet header, and outlet header by a drive unit (not shown). Alternatively, the magnetic refrigeration material section 15 may be configured as a single container containing magnetic refrigeration material, with the container filled with magnetic refrigeration material. The container is made of a material that allows heat-transporting fluid to pass through, such as a mesh material. In the example shown in Figure 2, the magnetic refrigeration material section 15 is formed in the shape of a hollow disc, and for example, has a rotation axis (not shown) at the center of the disc. The magnetic refrigeration material section 15 is connected to the rotation axis and rotates by the drive unit.

[0015] The magnet 16 is positioned so as to sandwich the magnetic refrigeration material section 15. The magnetic refrigeration material section 15 has a portion sandwiched by the magnet 16 and a portion not sandwiched by the magnet 16. Of the magnetic refrigeration material section 15, the portion to which a magnetic field is applied by the magnet 16 is called the excited section A, and the portion to which no magnetic field is applied is called the unexcited section B (see Figure 3). In the excited section A, a magnetic field is applied to the magnetic refrigeration material section 15, and in the unexcited section B, no magnetic field is applied to the magnetic refrigeration material. As the magnetic refrigeration material section 15 moves relative to the magnet 16, the excited section A and the unexcited section B alternate.

[0016] Since the magnetic refrigeration material section 15 moves relative to the magnet 16, the energized section A and the de-energized section B do not refer to fixed parts of the magnetic refrigeration material section 15. Focusing on a specific magnetic refrigeration material within the magnetic refrigeration material section 15, when the magnetic refrigeration material moves relative to the magnet 16 and is in a part where a magnetic field is applied by the magnet 16, it becomes the energized section A. When it moves to a part where no magnetic field is applied, the magnetic refrigeration material becomes the de-energized section B.

[0017] In the example shown in Figure 2, two sets of magnets 16 are installed to sandwich the magnetic refrigeration material section 15, and the magnetic refrigeration material section 15 has two sets of continuously alternating excited sections A to which a magnetic field is applied and unexcited sections B to which no magnetic field is applied. In other words, the magnetic refrigeration material section 15 is composed of a continuum that includes excited sections A to which a magnetic field is applied and unexcited sections B to which no magnetic field is applied. Here, a continuum is a structure in which there is no space between excited sections A and unexcited sections B that is not filled with magnetic refrigeration material, and the excited sections A and unexcited sections B may be separated by a guide member 18 or the like.

[0018] <Flow path of heat-transferring fluid> The inlet header and outlet header are provided before and after the magnetic refrigeration material section 15 in the direction of movement relative to the magnet 16. As described above, the magnetic refrigeration material section 15 has energized sections A and unenerged sections B formed in a continuous alternating manner. In the example shown in Figure 3, the heat-transferring fluid flows from the top to the bottom of the paper in the energized section A, and from the bottom to the top of the paper in the unenerged section B. At this time, it is desirable that no leakage of the heat-transferring fluid occurs between the energized section A and the unenerged section B. For example, the guide member 18 has the function of suppressing leakage of the heat-transferring fluid between the energized section A and the unenerged section B.

[0019] The guide member 18 facilitates the flow of the heat-transporting fluid inside the magnetic refrigeration material section 15 in the appropriate direction. The appropriate direction is the direction of flow from the high-temperature side inlet header 13 to the low-temperature side outlet header 12 and the direction of flow from the low-temperature side inlet header 11 to the high-temperature side outlet header 14. The guide member 18 also suppresses the flow of the heat-transporting fluid inside the magnetic refrigeration material section 15 in an inappropriate direction. The inappropriate direction is the direction of flow from the high-temperature side inlet header 13 to the high-temperature side outlet header 14 and the direction of flow from the low-temperature side inlet header 11 to the low-temperature side outlet header 12.

[0020] The guide member 18 is positioned diagonally inside the magnetic refrigeration material section 15, along the direction in which the heat transfer fluid flows. In the example shown in Figure 3, the guide member 18 is positioned so that there is a gap between the upper and lower ends of the magnetic refrigeration material section 15 and the guide member 18. The positioning of the guide member 18 is not limited to this, and the magnetic refrigeration material section 15 may be partitioned by the guide member 18. Alternatively, the system may be configured without a guide member 18.

[0021] Furthermore, the magnetic refrigeration material section 15 is configured such that the pressure loss in the appropriate direction of heat transfer fluid flow is smaller than the pressure loss in the inappropriate direction. This ensures that the direction of heat transfer fluid flow differs between the continuously alternating energized section A and the unenergetic section B. This also suppresses leakage of the heat transfer fluid between the energized section A and the unenergetic section B.

[0022] To suppress leakage of the heat-transporting fluid, it is preferable that the pressure loss in the unsuitable direction of the heat-transporting fluid flow is sufficiently greater than the pressure loss in the suitable direction. Sufficiently greater means, for example, that the pressure loss differs by more than twice. For example, the magnetic refrigeration material section 15 is configured such that the pressure loss in the direction of heat-transporting fluid inflow from the inlet header is smaller than the pressure loss in the direction perpendicular to the direction of heat-transporting fluid inflow from the inlet header.

[0023] Furthermore, the system may be configured such that the pressure loss when the heat-transporting fluid flows from the high-temperature side inlet header 13 to the low-temperature side outlet header 12 is smaller than the pressure loss when the heat-transporting fluid flows from the high-temperature side inlet header 13 to the high-temperature side outlet header 14. Also, the system may be configured such that the pressure loss when the heat-transporting fluid flows from the low-temperature side inlet header 11 to the high-temperature side outlet header 14 is smaller than the pressure loss when the heat-transporting fluid flows from the low-temperature side inlet header 11 to the low-temperature side outlet header 12.

[0024] When the density of the magnetic calorific value material filling the magnetic refrigeration material section 15 is uniform, the pressure loss is proportional to (length of the flow path through which the heat-transporting fluid flows / area through which the heat-transporting fluid flows). To reduce the pressure loss in the appropriate direction through which the heat-transporting fluid flows, for example, the length of the flow path in the appropriate direction can be shortened. Alternatively, by providing a guide member 18 parallel to the appropriate direction, the area through which the fluid passes in an inappropriate direction can be reduced, thereby increasing the pressure loss in the inappropriate direction.

[0025] The following describes a case where the length of the flow path is varied in order to differ the pressure loss. In the magnetic refrigeration material section 15, the length of the flow path in the appropriate direction for the heat-transporting fluid to flow may be configured to be shorter than the length of the flow path when the fluid flows in an inappropriate direction. For example, the distance from the center of the high-temperature side inlet header 13 to the center of the low-temperature side outlet header 12 may be configured to be shorter than the distance from the center of the high-temperature side inlet header 13 to the center of the high-temperature side outlet header 14. Also, the distance from the center of the low-temperature side inlet header 11 to the center of the high-temperature side outlet header 14 may be configured to be shorter than the distance from the center of the low-temperature side inlet header 11 to the center of the low-temperature side outlet header 12. In the following, such a distance relationship may be referred to as the "appropriate distance relationship".

[0026] Figure 4 shows the length of the flow path in the magnetic refrigeration material section 15. Figure 4 is a simplified representation of the unfolded view of the heat source block 10 shown in Figure 3. The distance from the center of the low-temperature side inlet header 11 to the center of the adjacent low-temperature side inlet header 11, across the low-temperature side outlet header 12, is defined as the cycle distance d. The cycle distance d is the circumferential distance at the radial center of the magnetic refrigeration material section 15. The distance from the center of the low-temperature side inlet header 11 to the center of the low-temperature side outlet header 12 is half of the cycle distance d, which is d / 2.

[0027] In Figure 4, the inlet and outlet headers positioned on either side of the magnet 16 are designated as the low-temperature side inlet header 11A, the high-temperature side inlet header 13A, the low-temperature side outlet header 12B, and the high-temperature side outlet header 14B, respectively. Since the heat-transporting fluid flows from the inlet header to the outlet header, the length of the flow path differs depending on which part of the header the fluid flows through. In the example shown in Figure 4, the length of the flow path in the appropriate direction for the heat-transporting fluid to flow is the distance from the center of the low-temperature side inlet header 11A to the center of the high-temperature side outlet header 14B. The length of the flow path in an inappropriate direction is the distance from the center of the low-temperature side inlet header 11A to the center of the low-temperature side outlet header 12B. For example, as shown in Figure 4, the appropriate distance relationship can be achieved by shifting the position of the high-temperature side outlet header 14B from directly below the low-temperature side outlet header 12B towards the high-temperature side inlet header 13A.

[0028] Furthermore, in order to vary the pressure loss, the density of the magnetic calorific material filling the magnetic refrigeration material section 15 may be varied. From the viewpoint of pressure loss, changing the density of the magnetic calorific material is equivalent to changing the area through which the heat-transporting fluid flows. For example, the density of the magnetic refrigeration material in the direction of inflow of the heat-transporting fluid from the inlet header may be set to be smaller than the density of the magnetic refrigeration material in the direction perpendicular to the inflow direction of the heat-transporting fluid from the inlet header.

[0029] Figure 5 shows the relationship between the application of a magnetic field to the magnetic refrigeration material section 15 and the flow of the heat-transporting fluid. Figure 5(a) shows an example in which a heat source block consisting of multiple units is used, as shown in Figure 6. Figure 5(b) shows an example in which a heat source block 10 according to this embodiment is used. The horizontal axis represents time. Time progresses in alphabetical order from a to e. Figure 6 shows an example of the configuration of a heat source block when the heat source block consists of multiple units 40.

[0030] As shown in Figure 6, the heat source block according to the comparative example comprises a unit 40 and a magnet 44. The unit 40 comprises a first header 41, a second header 42, and a magnetic refrigeration material section 43. The magnetic refrigeration material section 43 is filled with magnetic refrigeration material. Hereinafter, the first header 41 and the second header 42 may be collectively referred to as the "header".

[0031] The first header 41 and the second header 42 are connected via piping to a high-temperature side heat exchanger and a low-temperature side heat exchanger, respectively (not shown). The first header 41 and the second header 42 function as an inlet header for introducing heat-transferring fluid into the magnetic refrigeration material section 43 and an outlet header for discharging heat-transferring fluid from the magnetic refrigeration material section 15, respectively. The piping has, for example, a rotary valve that can reverse the direction in which the heat-transferring fluid flows through the magnetic refrigeration material section 15. Hereinafter, the header connected to the high-temperature side heat exchanger will be referred to as the "high-temperature side," and the header connected to the low-temperature side heat exchanger will be referred to as the "low-temperature side."

[0032] As shown in Figure 6, the heat source block according to the comparative example consists of a plurality of units 40 arranged in a circle. The units 40 move relative to the magnets 44, for example, by rotation. A magnetic field is applied to the magnetic refrigeration material in the portion sandwiched between opposing magnets 44.

[0033] Using Figure 5(a), we will explain the presence or absence of a magnetic field applied to a specific unit 40 when the heat source block consists of multiple units 40, and the flow of the heat transport fluid. First, from time a to time b, the unit 40 moves to a position where it is sandwiched between the magnets 44. At this time, a magnetic field is applied to the unit 40 by the magnets 44, and the part to which the magnetic field is applied becomes energized. During this time, no heat transport fluid flows into the unit 40.

[0034] At time b, the first unit 40 moves to a position where it is entirely sandwiched between the magnets 44 and becomes energized. At this point, the heat-transferring fluid begins to flow from the low-temperature side into the magnetic refrigeration material section 43 within the first unit 40. The heat-transferring fluid that has flowed into the magnetic refrigeration material section 43 flows out from the high-temperature side. Between time b and time c, the entire first unit 40 is in a position where it is sandwiched between the magnets 44, and the flow of the heat-transferring fluid is maintained in this state.

[0035] Between time c and time d, unit 40 moves to a position where it is not sandwiched between the magnets 44. At this time, unit 40 becomes de-energized from the part where the magnetic field is not applied by the magnets 44. During this time, no heat-transporting fluid flows into unit 40.

[0036] At time d, the first unit 40 moves to a position where it is not entirely sandwiched between the magnets 44, and becomes de-energized. At this point, the heat-transferring fluid begins to flow from the high-temperature side into the magnetic refrigeration material section 43 within the first unit 40. The heat-transferring fluid that has flowed into the magnetic refrigeration material section 43 flows out from the low-temperature side. Between time d and time e, the entire first unit 40 is in a position where it is not sandwiched between the magnets 44, and the flow of the heat-transferring fluid is maintained in this state.

[0037] After time e, unit 40 moves again to a position where it is sandwiched between the magnets 44, and the operation from time a to time e is repeated. When the heat source block consists of multiple units 40 in this way, the heat transfer fluid must be flowed while the entire unit 40 is either energized or de-energized, and it is not possible to flow the heat transfer fluid continuously.

[0038] Next, using Figure 5(b), we will explain the presence or absence of magnetic field application to a specific magnetic refrigeration material and the flow of heat transport fluid when using the heat source block 10 according to this embodiment. First, from time a to time b, the magnetic refrigeration material moves to a position where it is sandwiched between the magnets 16. At this time, a magnetic field is gradually applied to the magnetic refrigeration material by the magnets 16. Between time a and time b, the magnetic refrigeration material is located between the low-temperature side inlet header 11A and the high-temperature side inlet header 13A shown in Figure 4. No heat transport fluid flows at this position, and no heat transport fluid flows into the magnetic refrigeration material.

[0039] At time b, one magnetic refrigeration material is positioned between the magnets 16 and becomes energized. At this point, a heat-transferring fluid flows through the first magnetic refrigeration material from the low-temperature side to the high-temperature side. Between time b and time c, the first magnetic refrigeration material is positioned between the magnets 16, and the flow of the heat-transferring fluid is maintained in this state. Between time c and time d, the first magnetic refrigeration material is positioned between the low-temperature side outlet header 12B and the high-temperature side outlet header 14B shown in Figure 4. During this time, the magnetic field applied to the first magnetic refrigeration material weakens. At this position, no heat-transferring fluid flows, and no heat-transferring fluid flows into the first magnetic refrigeration material.

[0040] At time d, the first magnetic refrigeration material is in a de-energized state. At this time, a heat-transferring fluid flows through the first magnetic refrigeration material from the high-temperature side to the low-temperature side. Between time d and time e, the first magnetic refrigeration material is in a position not sandwiched between the magnets 16, and the flow of the heat-transferring fluid is maintained in this state. After time e, the first magnetic refrigeration material moves again to a position sandwiched between the magnets 16, and the operation from time a to time e is repeated.

[0041] The flow of the heat-transferring fluid shown in Figure 5(b) represents the flow of the heat-transferring fluid to a specific magnetic refrigeration material. Focusing on a specific magnetic refrigeration material, a state occurs where the heat-transferring fluid does not flow, as shown from time a to time b, but the heat-transferring fluid may continuously flow in from the inlet header. In this way, when using the heat source block 10 according to this embodiment, heat exchange occurs sequentially from the smallest portion where the magnetic field is applied or removed. Therefore, as in the case where the heat source block consists of multiple units, there is no need to wait for the magnetic field of the entire unit to become uniform, and the capacity can be improved.

[0042] Furthermore, because the magnetic refrigeration material in the magnetic refrigeration material section 15 is uniform in the circumferential direction, the generation of cogging torque due to the rotation of the magnetic refrigeration material section 15 is suppressed. This makes it possible to rotate with less torque. In addition, compared to when the magnetic refrigeration material section 15 is configured as a unit, rotary valves and switching valves for switching the flow of the heat transport fluid are not required, and the generation of cavitation associated with opening and closing valves is reduced. This improves heat exchange performance.

[0043] Note that in FIG. 2, a configuration in which two sets of magnets 16 sandwiching the magnetic refrigeration material portion 15 are provided has been described, but the present invention is not limited thereto. Three or more sets of magnets 16 may be provided. FIG. 7 is a diagram showing a configuration example of the heat source block 10 when four sets of magnets 16 are provided. In the heat source block 10 shown in FIG. 7, four sets of an excited portion where a magnetic field is applied and a non-excited portion where no magnetic field is applied are formed continuously and alternately.

[0044] <First Modification Example> The heat source block 10 is not limited to that shown in FIG. 2. FIG. 8 is a diagram showing a configuration example of the heat source block 20 according to the first modification example. FIG. 9 is a diagram in which a cross-sectional view of the heat source block 20 shown in FIG. 8 cut along the two-dot chain line IX is developed into a plane. Also, in FIG. 9, the low-temperature side circuit 60 and the high-temperature side circuit 70 are shown together.

[0045] The heat source block 20 includes a magnetic refrigeration material portion 25 and a magnet 26. Further, it includes a low-temperature side inlet header 21 and a high-temperature side inlet header 23 as inlet headers, and a low-temperature side outlet header 22 and a high-temperature side outlet header 24 as outlet headers. Further, it includes a guide member 28 for controlling the flow of the heat transfer fluid and a seal member 29 for preventing leakage of the heat transfer fluid. Each component of the heat source block 20 has the same function as the heat source block 10.

[0046] The heat source block 20 according to the first modification example has a different configuration of the inlet header and the outlet header from the heat source block 10. In the heat source block 20, the inlet header and the outlet header are provided between the magnet 26 and the magnetic refrigeration material portion 25. In the example shown in FIG. 8, two sets of magnets 26 sandwiching the magnetic refrigeration material portion 25 are provided, and an excited portion A where a magnetic field is applied and a non-excited portion B where no magnetic field is applied are formed continuously and alternately in the magnetic refrigeration material portion 25 (see FIG. 9). The low-temperature side inlet header 21 and the high-temperature side outlet header 24 are configured to cover the entire excited portion A, and the low-temperature side outlet header 22 and the high-temperature side inlet header 23 are configured to cover the entire non-excited portion B.

[0047] The low-temperature side inlet header 21 is arranged with the same width as the magnet 26 and is arranged in close contact with the low-temperature side outlet header 22. The low-temperature side inlet header 21 and the low-temperature side outlet header 22 are arranged so as to cover the entire low-temperature side surface of the magnetocaloric material portion 25. The high-temperature side outlet header 24 is arranged with the same width as the magnet 26 and is arranged in close contact with the high-temperature side inlet header 23. The high-temperature side outlet header 24 and the high-temperature side inlet header 23 are arranged so as to cover the entire high-temperature side surface of the magnetocaloric material portion 25.

[0048] Regarding the flow path of the heat transfer medium in the heat source block 20 according to the first modification, it will be described with reference to FIG. 10. FIG. 10 is a diagram showing the length of the flow path in the magnetocaloric material portion. FIG. 10 is a diagram obtained by simplifying the developed view of the heat source block 20 shown in FIG. 9.

[0049] In FIG. 10, the inlet header and the outlet header arranged between a pair of magnets 26 are respectively referred to as the low-temperature side inlet header 21A and the high-temperature side outlet header 24A. The inlet header and the outlet header not sandwiched between a pair of magnets 26 are respectively referred to as the high-temperature side inlet header 23B and the low-temperature side outlet header 22B. In the excited portion A (see FIG. 9) sandwiched between the magnets 26, the heat transfer fluid flows from the low-temperature side inlet header 21A to the high-temperature side outlet header 24A. In the non-excited portion B (see FIG. 9) not sandwiched between the magnets 26, the heat transfer fluid flows from the high-temperature side inlet header 23B to the low-temperature side outlet header 22B.

[0050] The distance from the right end of the low-temperature side inlet header 21A to the left end of the low-temperature side outlet header 22B in FIG. 10 is defined as one cycle distance d. The distance from the central portion of the low-temperature side inlet header 21A to the central portion of the low-temperature side outlet header 22B is d / 2, which is half of the one cycle distance d. The magnetocaloric material portion 25 is configured such that, similar to the magnetocaloric material portion 15 of the heat source block 10, the pressure loss in the appropriate direction in which the heat transfer fluid flows is smaller than the pressure loss in the inappropriate direction. For example, the magnetocaloric material portion 25 is configured such that the length of the flow path in the appropriate direction in which the heat transfer fluid flows is shorter than the length of the flow path when flowing in the inappropriate direction.

[0051] In the example shown in Figure 10, the length of the flow path in the appropriate direction for the heat-transporting fluid is defined as the distance (L) from the center of the low-temperature side inlet header 21A to the center of the high-temperature side outlet header 24A. The length of the flow path in an inappropriate direction is defined as the distance (d / 2) from the center of the low-temperature side inlet header 21A to the center of the low-temperature side outlet header 22B. The magnetic refrigeration material section 25 is constructed such that d / 2 > L, for example, by reducing the thickness of the magnetic refrigeration material section 25.

[0052] Furthermore, the pressure loss may be varied by differences in the density of the magnetic refrigeration material and the guide members. The guide members 28 (see Figure 9) are arranged inside the magnetic refrigeration material section 25 along the direction in which the heat-transporting fluid flows. The guide members 28 are arranged radially to restrict the flow of the heat-transporting fluid in the circumferential direction of the magnetic refrigeration material section 25. This makes it easier for the heat-transporting fluid to flow in the appropriate direction.

[0053] Furthermore, the sealing member 29 (see Figure 9) may be configured to be wider than the width in which the guide member 28 is positioned. The sealing member 29 is installed between the low-temperature side inlet header 21 and the low-temperature side outlet header 22, and between the high-temperature side inlet header 23 and the high-temperature side outlet header 24. By configuring the sealing member 29 to be wider than the width in which the guide member 28 is positioned, heat transfer fluid will not flow into the magnetic refrigeration material between the guide members 28 in the area where the sealing member 29 is installed. This makes it possible to suppress leakage of heat transfer fluid between the energized section A and the unenergetic section B.

[0054] <Second Modification> Figure 11 shows an example of the configuration of the heat source block 30 according to the second modification. Figure 12 shows a part of the heat source block 30 according to the second modification as seen from above. The heat source block 30 comprises a magnetic refrigeration material section 35 and a magnet 36. It also includes a low-temperature side inlet header 31 and a high-temperature side inlet header 33 as inlet headers, and a low-temperature side outlet header 32 and a high-temperature side outlet header 34 as outlet headers. Each component of the heat source block 30 has the same function as the heat source block 10.

[0055] The heat source block 30 according to the second modification differs from the heat source block 10 in the configuration of the inlet header and outlet header. In the heat source block 30, the inlet header and outlet header are provided at one end and the other end of the disc-shaped magnetic refrigeration material section 25 in the radial direction. In the example shown in Figure 11, two sets of magnets 36 are installed to sandwich the magnetic refrigeration material section 35, and the magnetic refrigeration material section 35 is continuously and alternately formed into an excited section A to which a magnetic field is applied and a non-excited section B to which no magnetic field is applied (see Figure 12). The low-temperature side inlet header 31 is located radially outside the excited section A, and the high-temperature side outlet header 34 is located radially inside the excited section A. The low-temperature side outlet header 32 is located radially outside the non-excited section B, and the high-temperature side inlet header 33 is located radially inside the non-excited section B.

[0056] The flow path of the heat conduction medium in the heat source block 30 according to the second modification will be explained with reference to Figure 12. In the excitation section A, which is sandwiched between the magnets 36, the heat transfer fluid flows from the low-temperature side inlet header 31A to the high-temperature side outlet header 34A. In the non-excitation section B, which is not sandwiched between the magnets 36, the heat transfer fluid flows from the high-temperature side inlet header 33B to the low-temperature side outlet header 32B.

[0057] The magnetic refrigeration material section 35 is configured, similar to the magnetic refrigeration material section 15 of the heat source block 10, such that the pressure loss in the appropriate direction of heat transfer fluid flow is smaller than the pressure loss in the inappropriate direction. For example, the magnetic refrigeration material section 35 is configured such that the length of the flow path in the appropriate direction of heat transfer fluid flow is shorter than the length of the flow path when flowing in the inappropriate direction. The circumferential distance of the radial center of the magnetic refrigeration material section 35 shown in Figure 12 is the cycle distance d.

[0058] In the example shown in Figure 12, the length of the flow path in the appropriate direction for the heat-transporting fluid is defined as the distance (R) from the low-temperature side inlet header 31A to the high-temperature side outlet header 34A. The length of the flow path in an inappropriate direction is defined as d / 2, which is half the cycle distance d. The magnetic refrigeration material section 35 is constructed such that d / 2 > R, for example, by shortening the radial length (R) of the magnetic refrigeration material section 35. Furthermore, the pressure loss may be varied by differences in the density of the magnetic refrigeration material or by the guide members.

[0059] <Third Modification> The magnetic refrigeration material section 15 of the heat source block 10 may be constructed by laminating materials with different temperature characteristics. Figure 13 shows a cross-section of the magnetic refrigeration material section 15 when it is constructed by laminating materials with different temperature characteristics.

[0060] In the third modified example, the magnetic refrigeration material section 15 is constructed by stacking magnetic refrigeration materials 15A, 15B, 15C, 15D, and 15E, each having different temperature characteristics. Each magnetic refrigeration material has a different temperature at which the magnetic refrigeration effect is greatest (Curie temperature Tc). The magnetic refrigeration material section 15 is configured such that, for example, the Curie temperature Tc increases in the order of magnetic refrigeration materials 15A, 15B, 15C, 15D, and 15E. By arranging the magnetic refrigeration materials in series with respect to the direction in which the heat-transporting fluid flows, according to a predetermined temperature gradient, a high magnetic refrigeration effect can be obtained over a wide temperature range.

[0061] <Effects> The magnetic refrigeration system 1 of the present disclosure comprises a magnetic refrigeration material section 15 containing a magnetic refrigeration material through which a fluid passes; a magnet 16 that applies a magnetic field to the magnetic refrigeration material section 15 to raise its temperature; an inlet header through which the fluid flows into the magnetic refrigeration material section 15; an outlet header through which the fluid flows out of the magnetic refrigeration material section 15; and a drive unit that moves the magnetic refrigeration material section 15 relative to the magnet 16, the inlet header, and the outlet header. The inlet header includes a high-temperature side inlet header 13 and a low-temperature side inlet header 11, and the outlet header includes a high-temperature side outlet header 14 and a low-temperature side outlet header 12. The magnetic refrigeration material section 15 is composed of a continuum including an excitation section to which a magnetic field is applied by the magnet 16 and a non-excitation section to which no magnetic field is applied. The fluid flows from the low-temperature side inlet header 11 to the high-temperature side outlet header 14 in the excitation section and from the high-temperature side inlet header 13 to the low-temperature side outlet header 12 in the non-excitation section. In this case, the magnetic refrigeration system 1 using magnetic refrigeration material can have improved performance compared to a system composed of multiple units including magnetic refrigeration material. Here, the magnetic refrigeration material section 15 has a pressure loss in the direction of fluid inflow from the inlet header that is smaller than the pressure loss in the direction perpendicular to the direction of fluid inflow from the inlet header. In this case, the fluid flow can be properly maintained. Also, the magnetic refrigeration material section 15 has a density of magnetic refrigeration material in the direction of fluid inflow from the inlet header that is smaller than the density of magnetic refrigeration material in the direction perpendicular to the direction of fluid inflow from the inlet header. In this case, the fluid flow can be properly maintained. Furthermore, the magnetic refrigeration material section 15 has a pressure loss when the fluid flows from the high-temperature side inlet header 13 to the low-temperature side outlet header 12 that is smaller than the pressure loss when the fluid flows from the high-temperature side inlet header 13 to the high-temperature side outlet header 14. In this case, the fluid flow from the high-temperature side inlet header 13 to the high-temperature side outlet header 14 can be suppressed. Furthermore, in the magnetic refrigeration material section 15, the distance from the center of the high-temperature side inlet header 13 to the center of the low-temperature side outlet header 12 is shorter than the distance from the center of the high-temperature side inlet header 13 to the center of the high-temperature side outlet header 14.In this case, the flow of fluid from the high-temperature side inlet header 13 to the high-temperature side outlet header 14 can be suppressed. Furthermore, the magnetic refrigeration material section 15 has a pressure loss when the fluid flows from the low-temperature side inlet header 11 to the high-temperature side outlet header 14 that is smaller than the pressure loss when the fluid flows from the low-temperature side inlet header 11 to the low-temperature side outlet header 12. In this case, the flow of fluid from the low-temperature side inlet header 11 to the low-temperature side outlet header 12 can be suppressed. The magnetic refrigeration material section 15 also includes a guide member 18 that suppresses the flow of fluid from the high-temperature side inlet header 13 to the high-temperature side outlet header 14 and the flow of fluid from the low-temperature side inlet header 11 to the low-temperature side outlet header 12. In this case, the fluid flow can be properly maintained. Furthermore, the magnetic refrigeration material section 15 consists of a single container containing the magnetic refrigeration material. In this case, the fluid can be continuously supplied to the magnetic refrigeration material section 15. Furthermore, the fluid flows continuously from the high-temperature side inlet header 13 to the low-temperature side outlet header 12, and from the low-temperature side inlet header 11 to the high-temperature side outlet header 14. In this case, the capacity can be improved compared to a magnetic refrigeration system using magnetic refrigeration material that is composed of multiple units including magnetic refrigeration material. Also, the magnetic refrigeration material section 15 is disc-shaped and rotates by the drive unit. In this case, the fluid can be continuously supplied to the magnetic refrigeration material section 15. Furthermore, the magnetic refrigeration system of this disclosure includes a cover 17 fixed to the inlet header and the outlet header to prevent leakage of the fluid from the magnetic refrigeration material section 15. In this case, leakage of the fluid from the magnetic refrigeration material section 15 can be suppressed. Also, the magnetic refrigeration material section 15 is made up of laminated materials with different temperature characteristics. In this case, the capacity can be improved compared to a system using materials with the same temperature characteristics. Furthermore, the inlet header and the outlet header are provided between the magnet 26 and the magnetic refrigeration material section 25. In this case, the heat transfer fluid can be flowed uniformly, and the capacity can be improved compared to when the system consists of multiple units including magnetic refrigeration material.Furthermore, the inlet header and outlet header are provided in front of and behind the magnetic refrigeration material section 15 in the direction of movement relative to the magnet 16. In this case, the capacity can be improved compared to a magnetic refrigeration system using magnetic refrigeration material that is composed of multiple units including magnetic refrigeration material. Also, the inlet header and outlet header are provided at one end and the other end in the radial direction of the disc-shaped magnetic refrigeration material section 35. In this case, the magnetic flux density can be increased, and the capacity can be improved compared to a system composed of multiple units including magnetic refrigeration material.

[0062] Although embodiments have been described above, the technical scope of this disclosure is not limited to the embodiments described above. It is clear from the claims that combinations of two or more of the above embodiments, as well as various modifications or improvements to the above embodiments, are also included in the technical scope of this disclosure.

[0063] 1...Magnetic refrigeration system, 10, 20, 30...Heat source block, 15, 25, 35...Magnetic refrigeration material section, 60...Low temperature side circuit, 70...High temperature side circuit

Claims

1. A magnetic refrigeration system comprising: a magnetic refrigeration material section containing a magnetic refrigeration material through which a fluid passes; a magnetic field application circuit that applies a magnetic field to the magnetic refrigeration material section to raise its temperature; an inlet header through which the fluid flows into the magnetic refrigeration material section; an outlet header through which the fluid flows out of the magnetic refrigeration material section; and a drive unit that moves the magnetic refrigeration material section relative to the magnetic field application circuit, the inlet header, and the outlet header, wherein the inlet header includes a high-temperature side inlet header and a low-temperature side inlet header; the outlet header includes a high-temperature side outlet header and a low-temperature side outlet header; the magnetic refrigeration material section is composed of a continuum including an excitation section to which a magnetic field is applied by the magnetic field application circuit and a non-excitation section to which no magnetic field is applied; and the fluid flows from the low-temperature side inlet header to the high-temperature side outlet header in the excitation section and from the high-temperature side inlet header to the low-temperature side outlet header in the non-excitation section.

2. The magnetic refrigeration system according to claim 1, wherein the pressure loss in the direction of fluid inflow from the inlet header is smaller than the pressure loss in the direction perpendicular to the direction of fluid inflow from the inlet header.

3. The magnetic refrigeration system according to claim 1, wherein the density of the magnetic refrigeration material in the direction of fluid inflow from the inlet header is less than the density of the magnetic refrigeration material in a direction perpendicular to the direction of fluid inflow from the inlet header.

4. The magnetic refrigeration system according to claim 1, wherein the pressure loss when the fluid flows from the high-temperature side inlet header to the low-temperature side outlet header is smaller than the pressure loss when the fluid flows from the high-temperature side inlet header to the high-temperature side outlet header.

5. The magnetic refrigeration system according to claim 1, wherein the distance from the center of the high-temperature side inlet header to the center of the low-temperature side outlet header is shorter than the distance from the center of the high-temperature side inlet header to the center of the high-temperature side outlet header.

6. The magnetic refrigeration system according to claim 1, wherein the pressure loss when the fluid flows from the low-temperature side inlet header to the high-temperature side outlet header is smaller than the pressure loss when the fluid flows from the low-temperature side inlet header to the low-temperature side outlet header.

7. The magnetic refrigeration system according to claim 1, wherein the magnetic refrigeration material section comprises guide members that suppress the flow of the fluid from the high-temperature side inlet header to the high-temperature side outlet header and the flow of the fluid from the low-temperature side inlet header to the low-temperature side outlet header.

8. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the magnetic refrigeration material section comprises a single container containing the magnetic refrigeration material.

9. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the fluid flows continuously from the high-temperature side inlet header to the low-temperature side outlet header, and continuously from the low-temperature side inlet header to the high-temperature side outlet header.

10. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the magnetic refrigeration material portion is disc-shaped and rotates by the drive unit.

11. A magnetic refrigeration system according to any one of claims 1 to 7, comprising a cover fixed to the inlet header and the outlet header to prevent leakage of the fluid from the magnetic refrigeration material section.

12. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the magnetic refrigeration material portion is made up of stacked materials with different temperature characteristics.

13. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the inlet header and the outlet header are provided between the magnetic field application circuit and the magnetic refrigeration material section.

14. The magnetic refrigeration system according to any one of claims 1 to 7, wherein the inlet header and the outlet header are provided before and after the magnetic field application circuit in the direction of movement of the magnetic refrigeration material.

15. The magnetic refrigeration system according to claim 10, wherein the inlet header and the outlet header are provided at one radial end and the other end of the disc-shaped magnetic refrigeration material portion.

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