A permanent magnet assembly and design method thereof, magnetic refrigeration device and magnetic refrigeration system

Abstract

The present invention belongs to the field of magnetic refrigeration technology, and specifically discloses a permanent magnet assembly and a design method thereof, a magnetic refrigeration device and a magnetic refrigeration system. The permanent magnet assembly includes a hollow outer magnet cylinder and an inner magnet cylinder arranged in the hollow outer magnet cylinder. The outer magnet cylinder and the inner magnet cylinder are concentrically arranged and each includes a plurality of magnet blocks. The inner peripheral wall of the outer magnet cylinder and the outer peripheral wall of the inner magnet cylinder are spaced to form an annular air gap. The plurality of magnet blocks of the inner magnet cylinder and the outer magnet cylinder are configured to obtain an optimal volume exergy cooling capacity. The permanent magnet assembly and the design method thereof, the magnetic refrigeration device and the magnetic refrigeration system of the present invention have the advantages of obtaining an optimal volume exergy cooling capacity and forming uniformly alternating high magnetic field regions and low magnetic field regions.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic refrigeration, and in particular to a permanent magnet assembly and a design method thereof, a magnetic refrigeration device and a magnetic refrigeration system. Background Art

[0002] According to statistics, nearly 20% of the global electricity consumption is used for refrigeration, such as refrigerators and refrigeration systems such as air conditioners. In recent years, with the rise in global temperatures and the increase in energy consumption, new green and environmentally friendly refrigeration technologies without greenhouse effects have attracted much attention, and magnetic refrigeration is increasingly considered to be one of the technologies most likely to replace compression refrigeration.

[0003] Magnetic refrigeration is a complex multidisciplinary refrigeration technology. In the field of magnetic working fluid materials, its temperature change and entropy change have reached a bottleneck that cannot be broken through in a short time; therefore, research in the two core areas of the design of other permanent magnet components and heat transfer simulation is particularly important. Among them, the design and form of the magnetic field source determine the form, system distribution and amount of cooling generated by the magnetic refrigeration device used by the permanent magnet component. However, as a conventional permanent magnet component, the magnetic field design only considers the size of the magnetic field and the volume of the air gap, and the design optimization is mainly based on structural size optimization. This makes the design of the permanent magnet component and the heat transfer simulation separated from each other, and cannot effectively guide the overall design of the permanent magnet component and the magnetic refrigeration device to which it is applied.

[0004] The existing magnetic refrigeration device is a device that uses the physical properties of magnetic working fluids for refrigeration. The technical basis of the device is the magnetocaloric effect of magnetic working fluids, that is, when a changing magnetic field is applied to the magnetic working fluid, the temperature of the magnetic working fluid will increase or decrease. When the magnetic field strength increases, the magnetic entropy of the magnetic working fluid decreases, heat is released, and the temperature increases. When the magnetic field strength decreases, the magnetic entropy of the magnetic working fluid increases, heat is absorbed, and the temperature decreases. Therefore, a magnetic refrigeration device generally needs to have: a changing magnetic field, a cold storage device for placing the magnetic working fluid, a heat transfer fluid, a cold end heat exchanger, a hot end radiator, and matching power components.

[0005] The magnetic working fluid in the cold storage device has the largest adiabatic temperature change and the strongest magnetocaloric effect at its Curie temperature. When the magnetic working fluid deviates from the Curie temperature, the magnetocaloric effect decreases. When the cold storage device is filled with only one magnetocaloric material, the temperature span of the cold storage bed is small. Therefore, in order to increase the temperature span of the cold storage device, a variety of magnetocaloric materials should be filled in the cold storage device. From the hot end to the cold end of the cold storage device, the Curie temperature of the magnetocaloric material gradually decreases.

[0006] The magnetization and demagnetization areas of the cold storage device are filled with magnetic fluid. The quality of the fluid flowing through the magnetic fluid area in the cold storage device is not the greater the better. Its quality value is related to the temperature span and operating conditions set by the magnetic refrigeration system. In addition, the pressure loss of the fluid flowing through the magnetic fluid is large, and the piston consumes a lot of power. When the length of the fluid flowing through the magnetic fluid area is longer, the pressure loss is greater, the piston consumes more power, and the energy efficiency of the fluid is lower. Therefore, when operating a magnetic refrigeration device, the appropriate magnetic fluid quality should be determined according to the temperature span and operating conditions of the magnetic refrigeration device.

[0007] As mentioned above, for the field of magnetic refrigeration, the design and heat transfer simulation of permanent magnet components are particularly important when the volume of the cold storage device is fixed, which makes it difficult to improve the quality of the magnetic medium contained and the temperature change and entropy change of the magnetic medium cannot be broken through in a short time. The traditional permanent magnet components use single-tube Halbach magnets, such as Figure 1 As shown, the magnets are evenly divided into n equal parts in the circumferential direction, and the direction of each magnet is distributed according to 2π / n.

[0008] For perfect magnetization Halbach, it means that the magnetic field direction at every point of the entire magnet satisfies:

[0009] B r =B rem cos(pφ), B φ =B rem sin(pφ), the magnetic field distribution is different when the p value is different in the perfect magnetization Halbach. Figure 2 It shows the typical different magnetic field conditions corresponding to a single-ring magnet, i.e. a magnet with only one circular ring column, when P is a positive integer and a negative integer, wherein reference numeral 10 shows a perfectly magnetized magnet; reference numeral 11 shows a magnetic field air gap, when P is a positive integer, the intermediate magnetic field is in a concentrated magnetic state, and when P is a negative integer, the intermediate magnetic field is in a non-concentrated magnetic state. The P value is an integer, and due to the periodic characteristics of sine or cosine, when P changes, the direction of the magnetic field changes accordingly, thus generating magnetic fields with different numbers of poles; wherein P=1 is a unipolar magnetic field, and P=2 is a quadrupole magnetic field.

[0010] However, since it is impossible to magnetize the magnet completely according to the above-mentioned perfect Halbach magnet in the actual processing and manufacturing of the magnet, the existing process generally divides the single-tube magnet into multiple magnet blocks for processing. However, due to the limitations of the processing technology and the structure of the single-tube magnet, the magnetic field generated by the magnet cannot obtain the optimal magnetic volume. Cooling capacity. In addition, the magnetic flux density in the high magnetic field area of ​​the magnetic field varies greatly and the lowest value in the low magnetic field area can only be reduced to about 0.5 T. In addition, the uniform multiple magnet blocks cause the overall magnet assembly to be larger in volume. Summary of the invention

[0011] Based on this, in view of the prior art, the technical problem to be solved by the present invention is to provide a method for obtaining an optimal magnetic volume. A permanent magnet assembly with high cooling capacity and a design method thereof, a magnetic refrigeration device and a magnetic refrigeration system.

[0012] To achieve the above purpose, the technical solution used in the present invention is as follows:

[0013] On the one hand, the present invention provides a permanent magnet assembly, which includes a hollow outer magnet cylinder and an inner magnet cylinder arranged in the hollow outer magnet cylinder, the outer magnet cylinder and the inner magnet cylinder are concentrically arranged and each includes a plurality of magnet blocks, the inner peripheral wall of the outer magnet cylinder and the outer peripheral wall of the inner magnet cylinder are spaced apart to form an annular air gap, and the plurality of magnet blocks of the inner magnet cylinder and the outer magnet cylinder are respectively configured to obtain an optimal volume. Cooling capacity.

[0014] In one technical solution, in order to obtain the optimal volume In the case of cooling capacity, the permanent magnet assembly includes a 2m-pole magnetic field uniformly distributed in a circumferential direction in an air gap, wherein m is a positive integer and m≥2, each magnetic field includes a low magnetic field region and a high magnetic field region, the average magnetic induction intensity of each low magnetic field region has a numerical range of 0-0.25T, and the average magnetic induction intensity of each high magnetic field region has a numerical range of 1.1-1.5T.

[0015] In one technical solution, each high magnetic field region and each low magnetic field region in the air gap has a uniform magnetic field strength.

[0016] In one technical solution, m is set to 2, and the high magnetic field regions and the low magnetic field regions are arranged alternately in sequence and there are four of them each.

[0017] In one technical solution, the inner magnet tube and the outer magnet tube are relatively divided into eight equal parts corresponding to each high magnetic field region and each low magnetic field region, and the multiple magnet blocks possessed by each equal part of the relative inner magnet tube and outer magnet tube each include multiple permanent magnets and at least one soft iron body, and the soft iron body of the inner magnet tube and the soft iron body of the outer magnet tube are arranged opposite to each other.

[0018] In one technical solution, each high magnetic field region and each low magnetic field region are circumferentially arranged at a central angle of 45°.

[0019] In one technical solution, multiple permanent magnets are all N42 NdFeB permanent magnets.

[0020] On the other hand, the present invention provides a method for designing a permanent magnet assembly, wherein the permanent magnet assembly is any of the above permanent magnet assemblies, and the method for designing the permanent magnet assembly comprises the following steps:

[0021] Providing an ideal Halbach magnetic field, which includes an inner magnet cylinder and an outer magnet cylinder designed to form a 2m-pole magnetic field, wherein m is a positive integer and m≥2;

[0022] Parameterizing the magnet structure, including setting value ranges for magnet dimensions of a first outer diameter of the inner magnet cylinder, a second outer diameter of the outer magnet cylinder, an air gap, and an overall length of the permanent magnet assembly;

[0023] Performing a parametric scan in the simulation software includes obtaining simulation results of the first outer diameter, the second outer diameter, the air gap, and the overall length of the permanent magnet assembly;

[0024] An optimization simulation is performed on a cold storage device for installation in the air gap, which includes calculating and obtaining an optimal magnet size corresponding to an optimal cooling capacity of the whole machine under a preset temperature span;

[0025] Reverse magnetic field segmentation optimization, which includes segmenting the inner magnet cylinder and the outer magnet cylinder to obtain the corresponding structures of the respective multiple magnet blocks;

[0026] Provide the first objective function: Where: Represents magnetic energy Q c Indicates cooling capacity, ΔT span Indicates temperature span, T c Indicates the cold end temperature; V mag represents the volume of the magnet;

[0027] A topology optimization algorithm is used, which includes the Q c Simulation calculation and topological optimization calculation based on the first objective function are performed to calculate the optimal unit volume magnet Refrigeration capacity and cooling capacity.

[0028] On the other hand, the present invention provides a magnetic refrigeration device, which includes any of the above permanent magnet assemblies, a cold storage assembly and a drive assembly, the cold storage assembly is annular and assembled in the air gap, and the drive assembly drives the inner magnet cylinder and the outer magnet cylinder to rotate synchronously relative to the cold storage assembly.

[0029] In one technical solution, a cold storage device assembly includes a total of 2n cold storage devices connected in sequence, wherein n is a positive integer, n≥2, and the number of cold storage devices is twice the number of magnetic fields formed by the permanent magnet assembly. Each cold storage device includes a hollow cavity with openings at both ends and an upper cover plate and a lower cover plate respectively sealing one end opening, wherein a hot inlet and a cold inlet for a heat transfer fluid to flow in are provided on the upper cover plate, and a hot outlet and a cold outlet for a heat transfer fluid to flow out are provided on the lower cover plate; a driving component includes a first gear and a second gear relatively fixedly connected to a driving shaft, a third gear and a fourth gear coaxially rotating, and a rack meshed with the second gear and the fourth gear respectively, wherein the third gear is fixedly connected to an inner magnet cylinder; the fourth gear is fixedly connected to an outer magnet cylinder, the first gear and the second gear rotate under the drive shaft, thereby driving the third gear and the fourth gear to rotate relatively fixedly coaxially, and the second gear and the fourth gear are linked to each other by meshing with the rack; the synchronously rotating inner magnet cylinder and the outer magnet cylinder enable each cold storage device arranged at intervals in the plurality of cold storage devices to be in a high magnetic field region or a low magnetic field region at the same time.

[0030] In one technical solution, the total number of cold storage devices is set to eight, the number of magnetic fields is set to four, and the magnetic refrigeration device also includes a corresponding number of first connecting tubes, second connecting tubes, third connecting tubes and fourth connecting tubes, each of which is in plurality. Each first connecting tube and each second connecting tube are respectively and sequentially connected to the hot inlet and the cold inlet of the four cold storage devices arranged at intervals, and each third connecting tube and each fourth connecting tube are respectively and sequentially connected to the hot outlet and the cold outlet of the four cold storage devices arranged at intervals.

[0031] On the other hand, the present invention provides a magnetic refrigeration system, comprising any of the above magnetic refrigeration devices that form a fluid circulation, a condenser and an evaporator that are both connected to the cold storage assembly, the condenser is located downstream of the heating heat transfer fluid flowing out of the cold storage, and the evaporator is located downstream of the cooling heat transfer fluid flowing out of the cold storage.

[0032] Compared with the prior art, the present invention has the following beneficial effects: the permanent magnet assembly adopts a double-tube magnet structure including an inner magnet tube and an outer magnet tube, and based on the optimal volume Cooling capacity is achieved by optimal division of the multiple magnet blocks of the inner and outer magnet cylinders, and in addition, the permanent magnet assembly achieves an optimal volume The cooling capacity is improved. The magnetic flux density in the high magnetic field area of ​​the magnetic field remains basically unchanged and the minimum value in the low magnetic field area can be reduced to close to 0T. In addition, the multiple magnet blocks that are optimally divided also reduce the volume of the entire permanent magnet assembly. Correspondingly, the design method of the permanent magnet assembly provides a method based on obtaining the optimal volume. A new design method for reversely designing a permanent magnet component to increase cooling capacity and the designed permanent magnet component has the above-mentioned beneficial effects. Further, the magnetic refrigeration device and the magnetic refrigeration system also obtain the above-mentioned beneficial effects due to the permanent magnet component, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings. However, the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention, wherein:

[0034] Figure 1 It is a schematic diagram of a conventional single-tube Halbach magnet in the prior art;

[0035] Figure 2 Halbach magnets with different numbers of magnetic poles in the prior art;

[0036] Figure 3 It is a front view of the permanent magnet assembly of the present invention;

[0037] Figure 4 For corresponding to Figure 3 A partial cross-sectional view of

[0038] Figure 5 is a top view of the permanent magnet assembly of the present invention;

[0039] Figure 6 It is an exploded schematic diagram of a quarter of the permanent magnet assembly of the present invention;

[0040] Figure 7 It is a cross-sectional cloud diagram of the magnetic field of the permanent magnet assembly of the present invention;

[0041] Figure 8 It is a magnetic field waveform diagram of the permanent magnet assembly of the present invention;

[0042] Fig. 9 It is a schematic flow chart of the design method of the permanent magnet assembly of the present invention;

[0043] Fig.10 A schematic diagram of magnet dimensions of an ideal Halbach permanent magnet having an ideal Halbach magnetic field provided in the design method of a permanent magnet assembly of the present invention;

[0044] Fig.11 A magnet optimization segmentation curve diagram of the design method of the permanent magnet assembly of the present invention;

[0045] Fig.12 A schematic diagram showing the simulation results of the local structure of a multi-magnet block of the design method of the permanent magnet assembly of the present invention in the form of lines and surfaces;

[0046] Fig.13 For the corresponding Fig.12 Convert the line-surface method into a block-like representation;

[0047] Fig.14 A front view of the magnetic refrigeration device of the present invention from one direction;

[0048] Fig.15 A front view of the magnetic refrigeration device of the present invention from another direction;

[0049] Fig.16 This is a front view of the magnetic refrigeration device of the present invention from another direction and omitting the permanent magnet assembly;

[0050] Fig.17 A partial cross-sectional view of a cold storage device assembly of a magnetic refrigeration device of the present invention;

[0051] The reference numerals in the figure are as follows:

[0052] 100-permanent magnet assembly; 110-external magnet cylinder; 111-soft iron housing; 120-inner magnet cylinder; 130-air gap;

[0053] 200-cold storage assembly; 210-cold storage; 211-upper cover; 211A-hot inlet; 211B-cold inlet; 212-lower cover; 212A-hot outlet; 212B-cold outlet; 213-hollow cavity;

[0054] 300-driving assembly; 310-first gear; 320-second gear; 330-third gear; 340-fourth gear; 350-rack;

[0055] 400-high magnetic field area; 500-low magnetic field area;

[0056] 600 - first connecting pipe; 700 - second connecting pipe. DETAILED DESCRIPTION

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] refer to Figures 3 to 8 The embodiment of the present invention provides a permanent magnet assembly 100, which includes a hollow outer magnet cylinder 110 and an inner magnet cylinder 120 arranged in the hollow outer magnet cylinder 110, the outer magnet cylinder 110 and the inner magnet cylinder 120 are concentrically arranged and each includes a plurality of magnet blocks, the inner peripheral wall of the outer magnet cylinder 110 and the outer peripheral wall of the inner magnet cylinder 120 are spaced apart to form an annular air gap 130, and the plurality of magnet blocks of the inner magnet cylinder 120 and the outer magnet cylinder 110 are configured to obtain an optimal volume. Compared with the conventional single-cylinder magnet structure, the permanent magnet assembly 100 of the present invention is configured as a double-cylinder magnet structure having an inner magnet cylinder 120 and an outer magnet cylinder 110, and based on obtaining the optimal volume The plurality of magnet blocks of the inner magnet cylinder 120 and the outer magnet cylinder 110 are configured according to the cooling capacity, and the plurality of magnet blocks are not divided and processed in a uniform manner.

[0061] Please refer to further Figure 4 , Figure 7 and Figure 8 In one embodiment, after obtaining the above optimal volume In the case of cooling capacity, the permanent magnet assembly includes a 2m-pole magnetic field uniformly spaced in the air gap 130 around the circumferential direction, m is a positive integer, and m≥2, each magnetic field includes a low magnetic field area and a high magnetic field area, and since the number of magnetic fields is set to an even number greater than 4, accordingly, a plurality of uniformly alternating low magnetic field areas and high magnetic field areas are compactly provided around the inner magnet cylinder 120 and the outer magnet cylinder 110 around the circumferential direction. In a broad sense, the high magnetic field and the low magnetic field are divided by the strength of the average magnetic induction intensity. The average magnetic field intensity close to 0T is the low magnetic field domain, and the average magnetic field is much greater than zero. It is generally believed that the field greater than 1T is a strong magnetic field. In the field of magnetic refrigeration, the strong magnetic field is generally 0.6T, and generally above 1T. Specifically, the numerical range of the average magnetic induction intensity of each low magnetic field area of ​​the permanent magnet assembly 100 of the present invention is 0-0.25T, and the numerical range of the average magnetic induction intensity of each high magnetic field area is 1.1-1.5T, and, Figure 8The magnetic field waveform at the center of the permanent magnet assembly 100 is shown, wherein the peak value is the maximum magnetic field intensity, the trough is the minimum magnetic field intensity, the four troughs correspond to four low magnetic field areas, and the peak and its vicinity correspond to four high magnetic field areas.

[0062] Please refer to further Figure 7 and Figure 8 In one embodiment, each high magnetic field region and each low magnetic field region in the air gap 130 has a uniform magnetic field strength. In this way, the permanent magnet assembly 100 of the present invention can provide the cold storage assembly 200 located in the air gap 130 with uniform magnetic field strength and alternating high and low magnetic field regions, so as to realize efficient heat release and heat absorption of the cold storage assembly 200.

[0063] Please refer to further Figure 4 and Figure 7 In one embodiment, m is set to 2. In this specification, m is set to 2 for detailed description. The high magnetic field areas and the low magnetic field areas are arranged alternately in sequence and there are four of them. Specifically, there are four magnetic fields evenly spaced in the air gap 130, each magnetic field forms a high magnetic field area and a low magnetic field area, and each high magnetic field area and each low magnetic field area are arranged circumferentially at a central angle of 45°. Therefore, it can also be said that the permanent magnet assembly 100 is set to an inner and outer nested double-cylinder structure. Since each magnetic field has a pair of magnetic poles including 1 N pole and 1 S pole, that is, the number of pole pairs is 1, the permanent magnet assembly 100 of the present invention generates a quadrupole magnetic field distributed alternately in the air gap 130 between the inner and outer magnet cylinders 110. The understanding of the quadrupole is similar to the definition in the field of motors: that is, the definition of the number of motor poles is the same as the meaning of the number of motor pole pairs. The number of motor poles is the number of magnetic poles of the motor. The magnetic poles are divided into N poles and S poles. Generally, the number of magnetic poles appears in pairs, such as 2-pole motors and 4-pole motors. Figure 4 The figure shows a permanent magnet assembly 100 composed of a group of magnets with different magnetization directions and a specific arrangement of multiple magnet blocks thereof, wherein arrows indicate the magnetization directions of the permanent magnets. Further, Figure 7 The figure shows the quadrupole high field strength magnetic field area and magnetic field direction distribution. Each magnet block preferably uses N42 NdFeB permanent magnets with a remanence of 1.31 T. In addition, in order to reduce the amount of magnets used and ensure that the magnetic field strength remains basically unchanged, Figure 4 The cross-hatched magnet blocks shown are preferably made of 1008# steel.

[0064] Figure 7 The central cross-sectional cloud diagram of the permanent magnet assembly 100 is shown. The permanent magnet assembly 100 can generate four high magnetic field regions 400 and four low magnetic field regions 500 in the air gap 130. Figure 7 The middle arrow points to the N pole of the magnetic field, and the magnetic field circulation direction is consistent with the direction of the arrow. The outer magnet tube 110 of the permanent magnet assembly 100 is preferably a soft iron shell 111 coated with a soft iron material.

[0065] Please refer to further Figure 4 , Figure 6 and Figure 7 In one embodiment, the inner magnet cylinder 120 and the outer magnet cylinder 110 are relatively divided into eight equal parts corresponding to each high magnetic field region and each low magnetic field region, and the multiple magnet blocks of each equal part of the inner magnet cylinder 120 and the outer magnet cylinder 110 include multiple permanent magnets and at least one soft iron body. Figure 6 In the exploded schematic diagram of 1 / 4 of the permanent magnet assembly 100 shown, it can be said that the permanent magnet assembly 100 includes four sub-permanent magnets, each of which includes a plurality of permanent magnets 112, 113, 114, 115, 116, 117, 121, 122, 123, 124 and soft iron bodies 118, 125; the boundaries of each mutually matched sub-permanent magnet are assembled by radial and axial fan-shaped blocks, and the assembly method is determined based on the principle of maximum magnetic energy product. The permanent magnets and soft iron bodies included in the multiple magnet blocks, the soft iron body of the inner magnet tube 120 and the soft iron body of the outer magnet tube 110 are arranged relative to each other.

[0066] Furthermore, compared to Figure 2 The permanent magnet assembly 100 of the present invention has a superimposed magnetic field, and the P value of the outer magnet cylinder 110 is: P 外 =2, P value of the inner magnet tube 120: P 内 =-2, by setting the permanent magnet assembly 100 to a combination of a positive integer for the P value of the outer magnet cylinder 110 and a negative integer for the P value of the inner magnet cylinder 120, the above technical effect of the permanent magnet assembly 100 is achieved.

[0067] Please refer to further Figures 9 to 13 The embodiment of the present invention also provides a design method of a permanent magnet assembly. Fig. 9 The flow of the design method of the permanent magnet assembly of the present invention is shown, wherein the permanent magnet assembly is any one of the permanent magnet assemblies 100 described above, which will not be described in detail here. The design method of the permanent magnet assembly includes the following steps:

[0068] S1: providing an ideal Halbach magnetic field, step S1 includes designing an inner magnet cylinder 120 and an outer magnet cylinder 110 to form a 2m-pole magnetic field, wherein m is a positive integer, and m≥2, and m is preferably set to 2, that is, forming a quadrupole magnetic field;

[0069] S2: Parameterize the magnet structure, see Fig.10Step S2 includes setting a value range for the magnet size of the first outer diameter R1 of the inner magnet tube 120, the second outer diameter R2 of the outer magnet tube 110, the air gap d, and the overall length L of the permanent magnet assembly. It can be understood that the overall length L of the permanent magnet assembly is equal to the axial length of the outer magnet tube 110. In addition, when the two end surfaces of the inner magnet tube 120 are flush with the two end surfaces of the outer magnet tube 110, the overall length L of the permanent magnet assembly is also equal to the axial length of the inner magnet tube 120.

[0070] S3: performing a parametric scan in a simulation software, which may be Ansys. Step S3 includes obtaining simulation results of the first outer diameter R1, the second outer diameter R2, the air gap d, and the overall length L of the permanent magnet assembly. The specific operation is to perform simulation in Ansys Maxwell, and each size parameter is stored as a text file.

[0071] S4: Optimizing and simulating the cold storage device installed in the annular air gap formed by the inner circumferential wall of the outer magnet cylinder and the outer circumferential wall of the inner magnet cylinder. The optimization simulation can be performed by combining Ansys and MATLAB. Step S4 includes calculating the optimal magnet size corresponding to the optimal cooling capacity of the whole machine under a preset temperature span, wherein the preset temperature span can be set to 15K. The optimal magnet size is calculated by using the udf of Ansys and the source code provided by MATLAB. The MATLAB program reads the above-mentioned stored text file data, and combines the cold storage device simulation program in MATLAB to obtain the optimal magnet size corresponding to the optimal cooling capacity of the whole machine under a temperature span of 15K.

[0072] S5: Reverse magnetic field segmentation optimization, step S5 includes segmenting the inner magnet tube 120 and the outer magnet tube 110 to obtain the corresponding structures of their respective multiple magnet blocks, which is implemented using the code that comes with MATLAB and adopts the idea of ​​Voronoi diagram. Specifically, the obtained optimal magnet size is brought into MATLAB for joint simulation, and the segmentation of the inner magnet tube 120 and the outer magnet tube 110 is implemented based on the reciprocity definition, that is, specifically combined with the idea of ​​Voronoi diagram or greedy algorithm to obtain the structure of their respective multiple magnet blocks.

[0073] S6: Provide a first objective function: Where: Represents magnetic energy , Q c Indicates cooling capacity, ΔT span Indicates temperature span, T c Indicates the cold end temperature; V mag represents the volume of the magnet, where the first objective function represents the unit volume of the magnet Refrigeration capacity, and adopts "magnetic energy " to express.

[0074] S7: Using the topology optimization algorithm, step S6 includes the Q c Simulation calculation and topological optimization calculation based on the first objective function are performed to calculate the optimal unit volume magnet Refrigeration capacity and refrigeration capacity, wherein the topology optimization algorithm adopts the MMA optimization algorithm. Specifically, after completing the above-mentioned reverse magnetic field segmentation optimization S5 step, the result is substituted into the above-mentioned first objective function and the MMA topology optimization algorithm is further adopted to further optimize the size of each magnet block based on the parameters of air, permanent magnet and soft iron.

[0075] In summary, in order to obtain the optimal volume Refrigeration capacity. The design method of the permanent magnet assembly of the present invention provides a first objective function, and reversely designs the magnetic field based on the first objective function, that is, to obtain the optimal magnetic field strength, the best cooling capacity and the temperature span at the minimum cost.

[0076] Please refer to further Fig.10 In one embodiment, for the first objective function, the cooling capacity Q c Through Ansys simulation calculation, it is found that the ideal Halbach design is a case of using a quadrupole double-cylinder magnet. Based on this, the parametric scanning step S3 in Ansys specifically includes parameterizing the magnet structure, specifically: the first outer diameter R1 of the inner magnet cylinder 120 is set to: 30mm-80mm, the second outer diameter R2 of the outer magnet cylinder 110 is set to: 100mm-180mm, the air gap d is set to: 20mm-30mm, and the overall length L of the permanent magnet assembly is set to: 200mm-300mm. Within the above value range of the structural parameters, the optimization operation is taken, so that the above first objective function will obtain an optimal unit volume magnet The cooling capacity is 1.08W / L, and the cooling capacity is 228W. At this time, the first outer diameter R1=80mm, the second outer diameter R2=150mm, the air gap d=24mm, and the overall length of the permanent magnet assembly L=200mm.

[0077] Please refer to further Figure 7 In one embodiment, if Figure 7 As shown, the high magnetic field region and the low magnetic field region are each formed into four. Figure 7 In the figure, with the right as the x-axis and the upward as the y-axis, the four high magnetic field regions are: -22.5°~22.5°, 67.5°~112.5°, 157.5°~202.5° and 247.5°~292.5°, that is; the remaining area is the low magnetic field area. Obviously, Figure 7 In the figure, according to the direction of the magnetic field lines indicated by the arrows, the magnetic field lines form four loops in total, located in four horizontal and vertical regions, e.g. Figure 7The above-mentioned -22.5°~22.5° region indicated by the middle arrow 101, i.e. the white region in the middle black ring, is a high field region, and its magnetic field strength is as follows: Figure 8 The average magnetic induction intensity of the peak shown, i.e. the high magnetic field area, is about 1.15T; the average magnetic induction intensity of the remaining low magnetic field areas is approximately 0T.

[0078] Please refer to further Fig. 9 , Fig.11 In one embodiment, the simulation software specifically adopts Ansys, and the reverse magnetic field segmentation optimization step includes:

[0079] Provide the second objective function: Where: n is the number of the same magnet structure of the corresponding inner magnet tube 120 and the outer magnet tube 110, S[{φ n}] is the magnetic energy product of the permanent magnet assembly 100;

[0080] Provide the integral formula: Where: B r is the magnetic induction intensity, H 2 is the magnetic field strength of the virtual magnetic field, Density function, and satisfies:

[0081]

[0082] According to the reciprocity theorem, and When the sum of the dot products of the permanent magnet assembly 100 is maximized and the magnetic energy product of the permanent magnet assembly 100 is maximized, the magnet size parameters obtained by the Ansys simulation calculation are brought into MATLAB for simulation using the above-mentioned method of combining Ansys and MATLAB. During the simulation process, the density function is obtained based on the virtual magnetic field, and then the magnetic induction intensity and the magnetic energy product are repeatedly optimized in combination with the random magnetic induction intensity until the optimal magnet block corresponding to the same magnet structure of the n inner magnet cylinders 120 and the outer magnet cylinder 110 is obtained.

[0083] In summary, for the design method of the permanent magnet assembly of the present invention, on the one hand: the value of N in the second objective function is 9, that is, the inner magnet tube 120 and the outer magnet tube 110 are divided into 9 identical magnet structures based on one-eighth of each other. N can be set according to actual needs. In the present invention, N=9 is used as an example for explanation. In addition, when N takes other numbers, they must satisfy the commonality principle, that is: based on the reciprocity theorem, on the basis of machinability, it must satisfy that the magnetic energy product of the target area, such as the high magnetic field area, is the largest. In the program iteration of the present invention, corresponding to Fig.11 , that is, the length of the straight line segment is close to the length of the curve, so that the magnetic energy product is maximized. Among them, the above-mentioned machinability refers to the Fig.12 The line-surface form shown is converted into Fig.13The block form shown in the figure, and then assemble the magnets with the same magnetization direction into one body, so that the permanent magnet assembly 100 obtains the maximum magnetic energy product, wherein According to the reciprocity theorem, to divide a magnet into N equal parts, the essence is and The dot product sum of is the largest, that is, the more even the two are, the larger the value is. Therefore, when is the horizontal axis, As the vertical axis, then the graph That is Fig.11 On the other hand, as described above, it satisfies the magnetic energy constructed by the present invention. In combination with the above two aspects, the permanent magnet assembly 100 designed by the design method of the permanent magnet assembly of the present invention satisfies the first objective function and the second objective function, namely, the magnetic energy The value of the magnetic energy product is maximum.

[0084] In summary, the present invention, based on Halbach theory, adopts the method of inversely designing the magnetic field from the objective function, and performs the optimization of the magnetic system about the linear objective lens by using the reciprocity theorem, so as to obtain the optimal magnet division.

[0085] Please refer to further Figures 14 to 17 The embodiment of the present invention further provides a magnetic refrigeration device. As for the working principle of magnetic refrigeration, it utilizes that the magnetic working fluid inside the cold storage device that stores the magnetic working fluid and can perform heat exchange will change in temperature in a changing magnetic field. The magnetic working fluid can be in different morphologies such as granular, sheet or microchannel. At the moment when the magnetic working fluid enters or exits the magnetic field, the magnetic working fluid will change in temperature due to the change in magnetic entropy of the magnetic working fluid. At the moment of entering the magnetic field, the magnetic working fluid releases heat, and at the moment of exiting the magnetic field, the magnetic working fluid absorbs heat. The greater the magnetic field gradient applied to the magnetic working fluid during entry and exit, the greater the amount of heat release and heat absorption. Taking out the cold in the magnetic working fluid is the magnetic refrigeration technology. The magnetic refrigeration device is further described below. The magnetic refrigeration device includes any of the above permanent magnet components 100, cold storage device components 200 and drive components 300. The cold storage device component 200 is annular and assembled in the air gap 130. The drive component 300 drives the inner magnet cylinder 120 and the outer magnet cylinder 110 to rotate synchronously relative to the cold storage device component 200. In this way, an external driving pump is used to drive the heat transfer fluid to flow through the magnetized cold storage assembly 200 to absorb the cold generated by the magnetic working fluid and then flow through the cold end heat exchanger. The fluid returning to room temperature then flows through the magnetized cold storage assembly 200 to absorb the heat released by the magnetic working fluid, and finally flows through the hot end radiator to release the heat back to the driving pump, thereby forming a magnetic refrigeration cycle.

[0086] Please refer to further Fig.14 , Fig.15 and Fig.17In one embodiment, the cold storage device assembly 200 includes a total of 2n cold storage devices 210 connected in sequence, wherein n is a positive integer, n≥2, and for the above m, preferably n=2m, the number of cold storage devices 210 is twice the number of magnetic fields formed by the permanent magnet assembly 100, and each cold storage device 210 includes a hollow cavity 213 with openings at both ends and an upper cover plate 211 and a lower cover plate 212 that seal one end opening respectively, a hot inlet 211A and a cold inlet 211B for the heat transfer fluid to flow in are provided on the upper cover plate 211, and a hot outlet 212A and a cold outlet 212B for the heat transfer fluid to flow out are provided on the lower cover plate 212, preferably, the connection line of the hot inlet 211A and the hot outlet 212A is arranged to cross the connection line of the cold inlet 211B and the cold outlet 212B, so that the heat exchange time of the heat transfer fluid in the cold storage device 210 can be extended, and further For example, the heating channel formed by the hot inlet 211A and the hot outlet 212A corresponds to when the magnetic working fluid in the cold storage device 210 is magnetized, the temperature of the magnetic working fluid increases, and the heat transfer fluid is introduced from the hot inlet 211A for heat exchange, thereby increasing the temperature of the heat transfer fluid; conversely, the cooling channel formed by the cold inlet 211B and the cold outlet 212B corresponds to when the magnetic working fluid in the cold storage device 210 is demagnetized, the temperature of the magnetic working fluid decreases, and the fluid is introduced from the cold inlet 211B for heat exchange, thereby decreasing the temperature of the heat transfer fluid. When the cold storage device 210 enters the magnetic field, the heating channel is flowing and the cooling channel is blocked. When the cold storage device 210 leaves the magnetic field, the cooling channel is flowing and the heating channel is blocked. That is to say, in each cold storage device 210, there is only one channel for the heat transfer fluid to flow, and the fluid flows of adjacent cold storage devices 210 are always opposite. The driving assembly 300 includes a first gear 310 and a second gear 320 relatively fixedly connected to a driving shaft, a third gear 330 and a fourth gear 340 rotating coaxially, and a rack 350 meshing with the second gear 320 and the fourth gear 340 respectively. A pulley can also be used to replace the rack 350 to achieve the same function. The third gear 330 is fixedly connected to the inner magnet cylinder 120, and the fourth gear 340 is fixedly connected to the outer magnet cylinder 110. When the driving shaft is connected to the servo motor and the driving force is provided by the servo motor, the first gear 310 and the second gear 320 are rotated by the driving shaft to drive the third gear 330 and the fourth gear 340 to rotate coaxially relatively fixedly, and the second gear 320 and the fourth gear 340 are meshed with the rack 350 to interlock with each other. It should be noted that in order to ensure that the third gear 330 and the fourth gear 340 are synchronized, that is, the rotation speed is the same, the gear ratio of the third gear 330 to the first gear 310 is equal to the gear ratio of the fourth gear 340 to the second gear 320. The synchronously rotating inner magnet cylinder 120 and outer magnet cylinder 110 enable each of the plurality of cold storage devices 210 disposed at intervals to be in a high magnetic field region or a low magnetic field region at the same time.Therefore, by setting the third gear 330 and the fourth gear 340 that rotate synchronously, it is ensured that the inner magnet tube 120 and the outer magnet tube 110 of the permanent magnet assembly 100 rotate synchronously, thereby ensuring that the magnetic field at the air gap 130 can evenly change between high and low magnetic fields, so that the magnetic working medium in the corresponding cold storage device 210 is alternately magnetized and demagnetized to cool.

[0087] Please refer to further Fig.16 In one embodiment, the total number of cold storage devices 210 is set to eight, and the number of magnetic fields is set to four, that is, the cold storage device assembly 200 is formed by eight cold storage devices 210 connected in a ring, and the magnetic refrigeration device also includes a first connecting pipe 600, a second connecting pipe 700, a third connecting pipe (not shown) and a fourth connecting pipe (not shown) of corresponding number and all of which are multiple. In this embodiment, only four of the cold storage devices 210 are used, and the connecting ends of the connecting pipes connected to the corresponding cold storage devices 210 are located between the rotating inner magnet cylinder 120 and the outer magnet cylinder 110. Therefore, the rotation of the inner magnet cylinder 120 and the outer magnet cylinder 110 will not interfere with the connecting pipes. Each first connecting tube 600 and each second connecting tube 700 are respectively connected in sequence with the hot inlet 211A and the cold inlet 211B of the four cold storage devices 210 arranged at intervals, and each third connecting tube and each fourth connecting tube are respectively connected in sequence with the hot outlet 212A and the cold outlet 212B of the four cold storage devices 210 arranged at intervals. As described above, the annular cold storage device assembly 200 of the magnetic refrigerator device of this embodiment is arranged in the high and low magnetic field areas in the air gap 130, and the high and low magnetic fields are arranged at intervals. Therefore, the two groups of four cold storage devices 210 arranged at intervals are in a magnetized or demagnetized state at the same time, and the four cold storage devices 210 in the same state can be connected to a converging pipe through four connecting tubes connected to the same type of openings, thereby For example, when four cold storage devices 210 in the same magnetization or demagnetization state enter the high magnetic field area and are in the magnetization state at the same time, the magnetic working fluid releases heat, so that the heat transfer fluid flowing through each cold storage device 210 absorbs the released heat and takes it out to the hot end radiator, so that the magnetic working fluid returns to room temperature again, preparing for further exiting the high magnetic field; and another group of four cold storage devices 210 in the same magnetization or demagnetization state are now exiting the high magnetic field and entering the low magnetic field, that is, the state is in the demagnetization state. At this time, the magnetic working fluid absorbs heat, and accordingly, the heat exchange fluid flowing through each cold storage device 210 exchanges heat with the magnetic working fluid and absorbs heat, making the temperature lower, and then flows into the cold end heat exchanger, thereby realizing the circulation and cooling function of the heat transfer fluid of the magnetic refrigeration device.

[0088] An embodiment of the present invention also provides a magnetic refrigeration system (not shown), for example, an air conditioner, which includes any of the above magnetic refrigeration devices that form a fluid cycle, a condenser and an evaporator that are both connected to the cold storage assembly 200, the condenser that performs the same function as the above hot-end radiator is located downstream of the warming heat transfer fluid flowing out of the cold storage 210, and the evaporator that performs the same function as the above cold-end heat exchanger is located downstream of the cooling heat transfer fluid flowing out of the cold storage 210. It can be seen that according to the working principle of refrigeration of the air conditioner, the magnetic refrigeration system also includes a driving pump and a control valve. The driving pump drives the heat transfer fluid to flow through the magnetized cold storage 210 to absorb the heat released by the magnetic working fluid, and then flows through the condenser. The fluid that returns to room temperature then flows through the demagnetized cold storage 210 to absorb the cold generated by the magnetic working fluid, and then flows through the evaporator to release the cold, thereby forming a magnetic refrigeration cycle. In addition, the working methods of the various components of the air conditioner are not repeated here. Since the various high magnetic field areas and low magnetic field areas of the magnetic refrigeration system move periodically under the drive of the driving component 300, there is always a group of cold storage devices 210 that realize refrigeration, thereby realizing the efficient refrigeration function of the magnetic refrigeration system.

[0089] In summary, the present invention designs magnetic field regions alternating between high magnetic fields and low magnetic fields so that when the permanent magnet assembly 100 rotates, the magnetic fluid in each corresponding cold storage device 210 can continuously pass through the high magnetic field region and the low magnetic field region in turn, thereby continuously extracting the cold from the magnetic fluid.

[0090] Unless otherwise specifically stated, the relative arrangement of the parts set forth in these embodiments does not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0091] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0092] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0093] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0094] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A permanent magnet assembly, It is characterized in that include: a hollow outer magnet cylinder; The inner magnet cylinder is arranged in the outer magnet cylinder, the outer magnet cylinder and the inner magnet cylinder are concentrically arranged and each includes a plurality of magnet blocks, the inner peripheral wall of the outer magnet cylinder and the outer peripheral wall of the inner magnet cylinder are spaced apart to form an annular air gap, and the plurality of magnet blocks of the inner magnet cylinder and the outer magnet cylinder are configured to obtain an optimal volume. Cooling capacity; 2m magnetic fields are evenly distributed in the air gap around the circumferential direction, where m is a positive integer and m≥2, and each of the magnetic fields includes a low magnetic field region and a high magnetic field region. The numerical range of the average magnetic induction intensity of each low magnetic field region is 0-0.25T, and the numerical range of the average magnetic induction intensity of each high magnetic field region is 1.1-1.5T.

2. The permanent magnet assembly according to claim 1, It is characterized in that Each high magnetic field region in the air gap and each low magnetic field region has a uniform magnetic field strength.

3. The permanent magnet assembly according to claim 1, It is characterized in that The m is set to 2, the high magnetic field regions and the low magnetic field regions are alternately arranged in sequence and there are four of them, and each of the high magnetic field regions and each of the low magnetic field regions are circumferentially arranged at a central angle of 45°.

4. The permanent magnet assembly according to claim 3, It is characterized in that The inner magnet tube and the outer magnet tube are relatively divided into eight equal parts corresponding to each of the high magnetic field regions and each of the low magnetic field regions, and the multiple magnet blocks possessed by the relative inner magnet tube and the outer magnet tube in each equal part each include multiple permanent magnets and at least one soft iron body, and the soft iron body of the inner magnet tube and the soft iron body of the outer magnet tube are arranged opposite to each other.

5. A design method for a permanent magnet assembly, It is characterized in that The permanent magnet assembly is the permanent magnet assembly according to any one of claims 1 to 4, and the design method of the permanent magnet assembly comprises the following steps: Providing an ideal Halbach magnetic field, which includes an inner magnet cylinder and an outer magnet cylinder designed to form four magnetic fields; Parameterizing the magnet structure, including setting value ranges for magnet dimensions of the first outer diameter of the inner magnet cylinder, the second outer diameter of the outer magnet cylinder, the air gap, and the length; Performing a parametric scan in Ansys, which includes obtaining simulation results of the first outer diameter, the second outer diameter, the air gap, and the length parameters; Combine Ansys and MATLAB to perform cold storage optimization simulation, which includes calculating the optimal magnet size corresponding to the best cooling capacity of the whole machine under the preset temperature span; Reverse magnetic field segmentation optimization, which includes segmenting the inner magnet cylinder and the outer magnet cylinder to obtain respective corresponding structures of a plurality of magnet blocks; Provide the first objective function: Where: Represents magnetic energy Q c Indicates cooling capacity, ΔT span Indicates temperature span, T c Indicates the cold end temperature; V mag represents the volume of the magnet; A topology optimization algorithm was used, which included the Q c Simulate and calculate and perform topological optimization operation according to the first objective function to calculate the best unit volume magnet Refrigeration capacity and cooling capacity.

6. The method for designing a permanent magnet assembly according to claim 5, It is characterized in that The step of performing parametric scanning in Ansys specifically includes: setting the value ranges of the first outer diameter, the second outer diameter, the air gap and the length to 30mm-80mm, 100mm-180mm, 20mm-30mm and 200mm-300mm respectively.

7. The method for designing a permanent magnet assembly according to claim 5, It is characterized in that The reverse magnetic field segmentation optimization step comprises: Provide the second objective function: Where: n is the number of blocks of the same magnet structure of the corresponding inner magnet tube and outer magnet tube, S[{φ n }] is the magnetic energy product of the permanent magnet assembly; Provide integral formula ∫ Ω d 3 xB r1 (x)·H 2 (x), where: B r is the magnetic induction intensity, H 2 is the magnetic field strength of the virtual magnetic field, is a density function and satisfies: According to the reciprocity theorem, and When the sum of the dot products and the magnetic energy product of the permanent magnet assembly are maximized, the magnet size parameters obtained by Ansys simulation calculation are brought into Matlab for simulation. During the simulation process, the density function is obtained according to the virtual magnetic field, and then the magnetic induction intensity and the magnetic energy product are repeatedly optimized in combination with the random magnetic induction intensity until the optimal magnet block corresponding to the same magnet structure of n inner magnet cylinders and outer magnet cylinders is obtained.

8. A magnetic refrigeration device, It is characterized in that It comprises the permanent magnet assembly, the cold storage assembly and the driving assembly as described in any one of claims 1 to 4, wherein the cold storage assembly is annular and assembled in the air gap, and the driving assembly drives the inner magnet cylinder and the outer magnet cylinder to rotate synchronously relative to the cold storage assembly.

9. The magnetic refrigeration device according to claim 8, It is characterized in that The cold storage device assembly includes a total of 2n cold storage devices connected in sequence, wherein n is a positive integer, n≥2, the number of the cold storage devices is twice the number of magnetic fields formed by the permanent magnet assembly, each of the cold storage devices includes a hollow cavity with openings at both ends and an upper cover plate and a lower cover plate respectively sealing one end of the opening, a hot inlet and a cold inlet for a heat transfer fluid to flow in are provided on the upper cover plate, and a hot outlet and a cold outlet for a heat transfer fluid to flow out are provided on the lower cover plate; The driving assembly includes a first gear and a second gear fixedly connected to a driving shaft, a third gear and a fourth gear rotating coaxially, and a rack respectively meshing with the second gear and the fourth gear, the third gear being fixedly connected to the inner magnet cylinder; the fourth gear being fixedly connected to the outer magnet cylinder, the first gear and the second gear rotating under the driving of the driving shaft thereby driving the third gear and the fourth gear to rotate coaxially relatively fixedly, and the second gear and the fourth gear being linked to each other by meshing with the rack; The synchronously rotating inner magnet cylinder and outer magnet cylinder enable each of the plurality of cold storage devices that are arranged at intervals to be in a high magnetic field region or a low magnetic field region at the same time.

10. The magnetic refrigeration device according to claim 9, It is characterized in that The total number of the cold storage devices is set to eight, the number of the magnetic fields is set to four, and the magnetic refrigeration device also includes a first connecting tube, a second connecting tube, a third connecting tube and a fourth connecting tube of corresponding number and all of which are multiple. Each first connecting tube and each second connecting tube are respectively and sequentially connected to the hot inlet and the cold inlet of the four cold storage devices arranged at intervals, and each third connecting tube and each fourth connecting tube are respectively and sequentially connected to the hot outlet and the cold outlet of the four cold storage devices arranged at intervals.

11. A magnetic refrigeration system, It is characterized in that A magnetic refrigeration device as claimed in any one of claims 8 to 10 that forms a fluid circulation, a condenser and an evaporator that are both connected to the cold storage assembly, the condenser is located downstream of the temperature-raising heat transfer fluid flowing out of the cold storage, and the evaporator is located downstream of the temperature-lowering heat transfer fluid flowing out of the cold storage.

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