246 results about "Magnetic refrigeration" patented technology

The invention belongs to the technical field of rare earth functional materials, and particularly relates to a rare earth aluminate low-temperature magnetic refrigeration material and a preparation method and application thereof.The preparation method comprises the following steps that 1, rare earth metal nitrate and aluminum nitrate are added into water to be mixed, and a mixed solution is prepared; adding ammonia water into the mixed solution to prepare a precipitate; (2) carrying out annealing treatment on the precipitate to prepare a metal oxide; and (3) calcining the metal oxide to obtain the rare earth aluminate low-temperature magnetic refrigeration material. The rare earth aluminate which has the characteristics of stable structure, low preparation cost, strong mechanical property, high magnetic density and the like and is prepared by adopting a coprecipitation method and combining a high-temperature sintering technology has more excellent magnetocaloric properties in a low-temperature region.

The invention belongs to the field of magnetic refrigeration materials, and particularly discloses a gadolinium-based molybdate magnetic refrigeration material and a preparation method and application thereof. The gadolinium-based molybdate magnetic refrigeration material comprises GdXMoO4, wherein X is F, Cl, Br or I; the magnetic phase change temperature of the gadolinium-based molybdate magnetic refrigeration material is less than 2K, and the maximum magnetic entropy change of the gadolinium-based molybdate magnetic refrigeration material is greater than or equal to 12J. Kg <-1 >. K <-1 > when the magnetic field change is 0-50kOe. The gadolinium-based molybdate magnetic refrigeration material disclosed by the invention has extremely low magnetic phase transition temperature, has relatively high magnetocaloric efficiency in a low magnetic field, is an extremely low temperature region magnetic refrigeration material with excellent performance, and has a wide application prospect in the field of extremely low temperature magnetic refrigeration.

1. The name of the design product: magnetic refrigeration three-in-one wireless charger (W105). 2. The use of the design product: the design product is a magnetic refrigeration three-in-one wireless charger, which is used to charge electronic devices such as watches, mobile phones, and Bluetooth earphones. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: unfolded state perspective view 1.

The invention discloses a robot parallel liquid cooling circulation system based on magnetic refrigeration. The robot parallel liquid cooling circulation system comprises a plurality of liquid cooling cavities, cold liquid, a magnetic refrigeration device and an air cooling device. The liquid cooling cavities are arranged at the positions of heat sources on the robot respectively and used for cooling the positions of the heat sources, and the liquid cooling cavities are arranged in parallel; the cold liquid is filled in the liquid cooling cavity channel; the magnetic refrigeration device is connected and conducted with the liquid cooling cavity channel and at least cools the cold liquid; and the air cooling device is connected and conducted with the magnetic refrigeration device to discharge heat for the magnetic refrigeration device. According to the liquid cooling circulation system, by additionally arranging the magnetic refrigeration device and the air cooling device, more efficient and lower-temperature cold liquid is provided for the robot, the lower-temperature refrigeration requirement of the robot is met, and normal work of the robot is ensured.

The invention belongs to the field of magnetic materials, and particularly discloses europium-based silicate as well as a preparation method and application thereof. The general chemical formula of the europium-based silicate is Eu2SiO4, and the europium-based silicate is subjected to secondary magnetic phase change from a paramagnetic state to a ferromagnetic state at the magnetic phase change temperature of 5.8 K; and at the temperature of 5.5 K, when the magnetic field change is 0-2T, the maximum magnetic entropy change is greater than 10J. Kg <-1 >. K <-1 >. The europium-based silicate disclosed by the invention generates paramagnetic to ferromagnetic phase change near the liquid helium temperature, is accompanied by a low-magnetic-field giant magnetothermal effect near the magnetic phase change temperature, shows large magnetic entropy change and refrigerating capacity near the liquid helium temperature, and has a wide application prospect in the field of magnetic refrigeration in a liquid helium temperature region.

The invention discloses a gadolinium boron molybdate magnetic refrigeration material with triangular magnetic resistance and a preparation method and application of the gadolinium boron molybdate magnetic refrigeration material. The chemical formula of the material is Gd2B2MoO9, the material belongs to a triclinic system, and the space group is P-1; the crystal structure has the characteristic that nearest rare earth Gd ions have magnetic resistance file; the material is prepared by a solid phase method or a sol-gel method; the magnetic phase change temperature of the material is 0.7-0.9 K, the material shows a remarkable magnetothermal effect at low temperature, the maximum isothermal magnetic entropy change values of the material are 30.0-35.0 J / kg.K and 51.0-55.0 J / kg.K respectively under the magnetic field change of 0-2T and 0-5T, and the material can be applied to low-temperature magnetic refrigeration. The gadolinium boron molybdate Gd2B2MoO9 material with triangular magnetoresistance provided by the invention has the advantages of low raw material price, simple process and lower equipment requirement, and is suitable for industrial production.

The invention provides an extremely-low-temperature magnetic refrigeration material with a pyrochlore structure, the chemical formula of the extremely-low-temperature magnetic refrigeration material is Ce2Sn2O7, the extremely-low-temperature magnetic refrigeration material belongs to a cubic system, and the space group of the extremely-low-temperature magnetic refrigeration material is Fd-3m. Compared with a traditional magnetic refrigeration material (paramagnetic salt hydrate), the novel extremely-low-temperature magnetic refrigeration material Ce2Sn2O7 of the pyrochlore structure has good magnetocaloric performance, can achieve 100 mK-level extremely-low-temperature refrigeration in the heat insulation and demagnetization actual measurement process, and meanwhile has the advantages of being compact in structure, high in stability, large in magnetic entropy density, easy to prepare and the like.

To provide a bed structure, a heat source, a magnetic refrigeration apparatus with improved performance, and a method for manufacturing the bed structure.SOLUTION: A bed structure (10) is used in a magnetic refrigeration apparatus and equipped with a plurality of particles (11). The particles (11) have a magnetocaloric effect. Flow channels (14) through which fluid passes are formed between the particles (11). The bed structure (10) has a structure in which thermal conduction between the particles (11) is suppressed. The heat source comprises an application part which applies a magnetic field to the bed structure and particles. The heat source has a plurality of kinds of particles with different magnetocaloric effects. The magnetic refrigeration apparatus is equipped with a heat source and a moving part which moves fluid performing heat exchange with the particles.SELECTED DRAWING: Figure 1

The invention discloses a robot series liquid cooling circulation system based on magnetic refrigeration. The system comprises a plurality of liquid cooling cavity channels, a magnetic refrigeration device, an air cooling device and cold liquid; the liquid cooling cavities are arranged at the positions of heat sources on the robot and used for cooling the positions of the heat sources, and at least part of the liquid cooling cavities are arranged in series; the cold liquid is filled in the liquid cooling cavity channel; the magnetic refrigeration device is connected and conducted with the liquid cooling cavity channel and at least cools the cold liquid; and the air cooling device is connected and conducted with the magnetic refrigeration device to discharge heat for the magnetic refrigeration device. According to the liquid cooling circulation system, part of the liquid cooling cavities are connected in series, so that a liquid cooling network is relatively simple, fewer liquid pumps are adopted, and the cost is low.

The invention belongs to the technical field of magnetic refrigeration, and particularly discloses a rare earth europium-based zirconate magnetic refrigeration material and a preparation method and application thereof. The general chemical formula of the rare earth europium-based zirconate magnetic refrigeration material is (Eu1-xMx) (Zr1-yNy) O3, M is any one of Ca, Sr or Ba, N is any one of Nb, Ta, Ti or Hf, x is more than or equal to 0 and less than or equal to 0.5, y is more than or equal to 0 and less than or equal to 0.5, and the magnetic phase transition temperature of the rare earth europium-based zirconate magnetic refrigeration material is less than 10K. The magnetic refrigeration material shows excellent magnetocaloric performance near the liquid helium temperature, and is expected to be applied to the liquid helium temperature zone magnetic refrigeration technology; and the preparation method is simple in process, safe and environment-friendly, and can be applied to industrial production.

The invention relates to the technical field of heat insulation and demagnetization refrigeration, in particular to a heat insulation and demagnetization refrigeration material and a preparation method and application thereof. Wherein the heat insulation and demagnetization refrigeration material is an Eu2ZnGe2OS6 crystal. The heat insulation demagnetization refrigeration material is an Eu2ZnGe2OS6 crystal and has relatively small magnetic anisotropy, and a long-range magnetic orderliness phenomenon is not observed at 1.8 K or above. Compared with an existing traditional magnetic refrigeration material, when the magnetic field is adiabatically reduced from 7T to 0T, the material shows the maximum negative magnetic entropy difference as high as 43.11 J * kg <-1 > * K <-1 >, and has a wide development prospect in adiabatic demagnetizing refrigeration application in a 2-16K temperature zone and a sub-Kelvin temperature zone.

The application provides a single magnetic field operated high-efficiency regenerative full solid-state magnetic refrigeration device, which comprises at least one refrigeration unit, and the refrigeration unit comprises parallel arranged refrigeration layers and regenerative layers, wherein the refrigeration layer comprises a plurality of refrigeration pieces which are embedded in a first heat insulation material at intervals; the regenerative layer comprises a plurality of regenerative pieces which are embedded in a second heat insulation material, wherein refrigeration piece / regenerative piece=1, and the refrigeration unit is arranged so that the refrigeration layer and the regenerative layer make reciprocating translational motion respectively during operation, and the refrigeration pieces and the regenerative pieces have heat conduction therebetween. The magnetic refrigeration device of the application can operate under a single simple continuous magnetic field, the requirement for magnets is reduced, the device is more economical and environmentally friendly, and the device uses a plurality of regenerative pieces, the plurality of regenerative pieces simultaneously perform heat conduction at two motion terminals of cold and hot ends, the regenerative efficiency is greatly improved, and thus the regenerative factor and the refrigeration power density are improved.

The invention discloses application of potassium-based rare earth fluoride in magnetic refrigeration and a magnetic refrigeration device, and belongs to the field of magnetic functional materials. The series of magnetic card materials are single-phase potassium-based gadolinium fluoride, and the chemical formula is KGdF4. The series of magnetic card materials can obtain a large magnetocaloric effect under a low driving magnetic field, and a 0-5kOe, 0-10kOe or 0-20kOe variable magnetic field is applied to the series of magnetic card materials. Under a magnetic field of 0-20 kOe, isothermal magnetic entropy changes of 29.18 J * kg <-1 > * K <-1 >, 27.92 J * kg <-1 > * K <-1 > and 31.99 J * kg <-1 > * K <-1 > are obtained at the temperature of 2K. When the cubic phase KGdF4 does not have an external magnetic field, the specific heat peak value at a low-temperature 2K position reaches 19.20 J * kg <-1 > * K <-1 >; and when the external magnetic field is increased to 2T, the low-temperature specific heat peak value reaches 72.15 J * kg <-1 > * K <-1 >.

The invention discloses a room temperature magnetic refrigeration demonstration instrument based on a magnetothermal effect and a use method thereof. A magnetizer and a magnetic field controller are electrically connected, the magnetizer is provided with a magnetic field test module, the top of the magnetizer is provided with a manual rocking handle, the middle part of the magnetizer is provided with an electromagnet magnetic field space, and the upper and lower parts of the electromagnet magnetic field space are provided with pole heads; the magnetizing time control module controls the action time of the magnetic field action module; the electromagnet magnetic field space is used for placing a magnetic refrigeration working medium; the manual rocking handle is used for fixing the magnetic refrigeration working medium; the magnetic field test module is a millteslameter, and the temperature control module is composed of a heating table and a non-metal thermal insulation layer; the temperature testing module is a temperature sensor; the adiabatic temperature change of the tested magnetic refrigeration working medium along with the application and revocation of the external magnetic field is visually displayed through a temperature sensor and a millteslameter. The demonstration instrument is low in cost, simple and convenient to operate and visual in demonstration mode, and the design pays attention to safety and environmental friendliness.

1. The name of the product of this design: Magnetic Refrigeration Three-in-One Wireless Charger (MP13). 2. Purpose of this design product: charging mobile phones, electronic watches and other electronic products. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the design points: Stereoscopic diagram 1.

1. The name of the product of this design: Magnetic Refrigeration Wireless Power Bank (MP11‑MP14). 2. Purpose of this design product: charging mobile phones, electronic watches and other electronic products. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the key points of the design: Design 1 Stereoscopic drawing 1. 5. Designate Design 1 as the base design.

The invention discloses a La-Fe-Si-based magnetic refrigeration composite material based on an FHP technology and a preparation method thereof.The preparation method comprises the following steps that a La-Fe-Si-based magnetic refrigeration material with the particle size smaller than or equal to 100 microns is used as main phase particles, 0-5 wt% of pure Fe powder is added to serve as an adhesive, and pre-compaction is conducted after sufficient mixing; the particle size of the Fe powder is less than or equal to 20 microns; and the pre-compacted raw material powder is placed in an FHP rapid hot pressing sintering furnace, the vacuum degree lower than 10 <-3 > Pa is kept, high-temperature rapid hot pressing sintering forming is carried out under the continuous pressure of 10-100 MPa, secondary diffusion heat treatment is carried out in the protective atmosphere after cooling, and the La-Fe-Si-based magnetic refrigeration composite material is prepared. The FH P process is adopted, the high-temperature decomposition phenomenon of the 1: 13 phase is effectively inhibited, the pure Fe powder serves as a reaction type adhesive, the magnetocaloric performance and the mechanical performance of the block are further improved, and the comprehensive performance of the material is comprehensively improved.

The present invention discloses a method for preparing a rare earth-based multivalent manganese oxide low-temperature magnetic refrigeration material by a molten salt method, which relates to the technical field of magnetic functional materials. The steps are as follows: Weigh manganese dioxide powder and rare earth oxide powder according to the stoichiometric ratio of the rare earth-based multivalent manganese oxide, mix them with sodium chloride, and grind to obtain a mixed powder; sinter the mixed powder at a high temperature and cool it to room temperature with the furnace to obtain a sintered powder; wash the sintered powder with water to remove sodium chloride and dry it to obtain the product. The process of the present invention is simple and low in cost. The prepared rare earth-based multivalent manganese oxide has a large magnetocaloric effect near the liquid helium temperature range. Among them, the REMn2O5-type rare earth-based multivalent manganese oxide has an isothermal magnetic entropy change of up to 12.61 J kg ‑1 K ‑1 , and the relative cooling power RCP is up to 338 J kg ‑1 . It can be used as a low-temperature magnetic refrigeration material in low-temperature engineering, aerospace, medical devices and other fields.

The invention relates to the technical field of cooling systems, and provides a ship cooling system capable of being quickly regulated and controlled, which comprises a heat exchanger and a regenerator, the regenerator is connected with the heat exchanger, the regenerator is arranged on the upstream of the heat exchanger, a cooling medium flows through the regenerator and then enters the heat exchanger, and the regenerator cools the cooling medium according to the magnetic refrigeration principle or the phase change refrigeration principle. According to the ship cooling system capable of being adjusted and controlled rapidly, the cold accumulator is arranged on the upstream of the heat exchanger, the temperature of the cooling medium can be further reduced, more heat of the heat exchanger can be absorbed when the cooling medium flows through the heat exchanger, and therefore the temperature of the heat exchanger is reduced, and the heat exchanger operates safely and stably; and the influence of thermal shock on the service life of the heat exchanger is avoided.

The invention discloses a method capable of reducing the refrigeration interval of rare earth fluoride, and belongs to the field of magnetic functional materials. According to the method, diamagnetic ions K < + > are added into rare earth fluoride to reduce magnetic interaction among rare earth ions, so that a magnetic phase transformation point moves to a lower-temperature region, and a lower magnetic ordered temperature and a lower refrigeration interval are obtained while large magnetic entropy change is ensured. The series of materials are LnF3 (Ln = Tb, Dy, Ho, Er, Tm) powder samples and KLn1. 4F5.2 powder samples obtained after K < + > ions are introduced. In order to explore the influence of the addition of K < + > on the magnetic ordered temperature, a 100Oe variable magnetic field is respectively applied to the series of materials. The introduction of K < + > enables the Curivus temperature of the material to be obviously reduced to 3K or below. By comparing the effects of K < + > with different contents on the overall performance of the material, the optimal ratio of K / Gd is found, and under the optimal ratio of LnF3 series samples, before and after the K < + > is introduced, the changes of theta CW values are 4.34 to 2.04 K, 5.31 to 1.76 K, 8.31 to 2.54 K, 14.74 to 1.73 K and 3.59 to 1.75 K in sequence.

The present invention relates to the field of magnetic functional materials. The present invention discloses a use of a rare earth fluoride single crystal in magnetic refrigeration, a magnetic refrigeration method and a magnetic refrigeration device. A magnetocaloric material of the series is lithium rare earth fluoride, with the chemical formula of LiREF4, wherein RE is one or more of rare earth elements gadolinium, terbium, dysprosium, holmium, erbium, thulium and ytterbium. A magnetocaloric material single crystal of the series has extremely strong magnetic anisotropy. By applying a varying magnetic field of 0-20 kOe along the easy magnetization axis direction of the magnetocaloric material, LiGdF4, LiTbF4, LiHoF4, LiDyF4, LiErF4, LiYbF4 and LiTmF4 obtained isothermal magnetic entropy changes of 50.35 J·kg−1·K−1, 21.12 J·kg−1·K−1, 24.98 J·kg−1·K−1, 24.45 J·kg−1·K−1, 21.95 J·kg−1·K−1, 14.7 J·kg−1·K−1 and 0.692 J·kg−1·K−1, respectively, at 1.8K, 4K, 4K, 1.8K, 1.8K, 1.8K, and 18K. Wherein, the thermal conductivity of LiTbF4 and LiErF4 reaches 50 W·K−1·m−1 at 25K.

The invention relates to the technical field of heat-insulating and demagnetizing refrigeration, and discloses a heat-insulating and demagnetizing refrigeration material based on a Trellis crystal lattice and a preparation method and application of the heat-insulating and demagnetizing refrigeration material. The chemical formula of the heat insulation and demagnetization refrigeration material based on the Trellis crystal lattice is Gd2GeB2O8. A magnetic test result of the Gd2GeB2O8 crystal shows that the magnetic anisotropy of the crystal material is relatively weak and tends to magnetic isotropy, and a long-range magnetic orderliness phenomenon is not observed above 1.8 K. And when adiabatic demagnetization is carried out under initial conditions that T is equal to 3K and B is equal to 7T, the material can reach the maximum negative magnetic entropy difference of 51.68 J * kg <-1 > * K <-1 >, which shows that the Gd2GeB2O8 has a better application prospect in a 3-17K temperature zone and a sub-Kelvin temperature zone.

The invention discloses a rotary magnetic refrigeration component and magnetic refrigeration equipment. In the rotary magnetic refrigeration part, a plurality of magnetic refrigeration beds of a stator assembly are the same in shape and size, are all in the shape of a regular cylinder with an arc-shaped cross section and are arranged in a ring shape in a mutual close fit mode, and a cold end port and a hot end port are formed in the peripheral face of each magnetic refrigeration bed. The plurality of magnet units of the rotor assembly are arranged at intervals along the circumferential direction, and the plurality of magnet units are the same in shape and size; each magnet unit comprises a first main magnet, a second main magnet, a first auxiliary magnet, a second auxiliary magnet, a third auxiliary magnet, a fourth auxiliary magnet, a first magnetic conductive magnetic head and a second magnetic conductive magnetic head which occupy equal angles, and the angle occupied by the first permanent magnet is equal to the angle occupied by the gap between the magnet units. The product is low in cost, low in production difficulty, high in refrigeration efficiency and compact in structure.

The application discloses a preparation method of a wide-temperature-range large-magnetic-entropy lanthanum-iron-silicon-based room-temperature magnetic refrigeration material, which uses La, Fe, Co and Si powders as raw materials, and prepares the wide-temperature-range large-magnetic-entropy lanthanum-iron-silicon-based room-temperature magnetic refrigeration material through high-energy ball milling of the raw materials under a protective atmosphere, and then through pressing and annealing heat treatment. The high-energy ball milling-annealing method for preparing the lanthanum-iron-silicon-based room-temperature magnetic refrigeration material has the advantages that the obtained lanthanum-iron-silicon-based room-temperature magnetic refrigeration material has a Curie temperature in a room-temperature range, a wide working temperature range and excellent magnetic heat performance, can provide a new idea for preparation of high-performance lanthanum-iron-silicon-based room-temperature magnetic refrigeration material, and has the advantages of simple preparation process, low cost, low requirement on reaction equipment and suitability for popularization and application.

The invention relates to the technical field of magnetic refrigeration, in particular to an outdoor unit and a magnetic heat pump air conditioner. The invention aims to solve the problem of temporary non-magnetic refrigeration air conditioner products in the prior art. In order to achieve the purpose, the outdoor unit comprises a shell provided with a first partition plate which divides the shell into an upper layer space and a lower layer space; the magnetic refrigeration unit comprises a driving mechanism, a transmission mechanism, a magnetic field assembly, a heat regenerator, a pump body and a connecting pipeline, the driving mechanism is connected with the magnetic field assembly through the transmission mechanism, the pump body is arranged to be capable of driving a heat exchange medium to flow in the connecting pipeline and the heat regenerator, and parts of the driving mechanism, the magnetic field assembly, the heat regenerator and the pump body are arranged in the upper-layer space; the rest are arranged in the lower-layer space; the outdoor heat exchanger is arranged in the upper-layer space or the lower-layer space and communicates with the heat regenerator; and the outdoor fan is arranged on one side of the outdoor heat exchanger. The invention provides a specific layout mode of the magnetic refrigeration unit, so that an outdoor unit product is compact in structure and good in operation stability.

The chemical formula of the Gd-Al-based room-temperature magnetic refrigeration material is Gd < 3-x > LaxAl < 2 >, and x is greater than or equal to 0 and less than or equal to 0.3. The invention discloses a preparation method and an application method of a Gd-Al-based room-temperature magnetic refrigeration material. According to the room-temperature magnetic refrigeration material and the preparation method thereof, the substitution atom-La atom is introduced into the Gd3Al2 alloy, the proportion of the content of Gd and La elements in the room-temperature magnetic refrigeration material is adjusted, the magnetic phase transition temperature is continuously adjustable within the temperature range of 252-275 K, and the refrigeration temperature range is greatly widened.

La(Fe,Si) has high pulverizability and does not require a large load to be turned into a powder. 13 H α The present invention provides a magnetic refrigeration material, a method for producing the same, and a magnetic refrigeration apparatus equipped with the magnetic refrigeration material. [Solution] The magnetic refrigeration material of the present invention is based on the following general formula (1) TIFF2026066207000015.tif7170[In formula (1), M represents one or more elements selected from the group consisting of Mn and Co, and A represents the element Al. x, y, a, b, c, and z are 0≦x≦0.4, 1.0 respectively.

The invention belongs to the technical field of magnetic refrigeration materials, and particularly relates to manganese pentaethylenehexamine hydrochloride and a preparation method and extremely low temperature magnetic refrigeration application thereof. The chemical formula of the extremely low temperature magnetic refrigeration material is [Mn (C10H28N6)] Cl2; the magnetic phase transition temperature of the extremely-low-temperature magnetic refrigeration material is lower than 0.4 K. The extremely-low-temperature magnetic refrigeration material has a large magnetothermal effect near 1K, and when the magnetic field change is 0-5T, the maximum magnetic entropy change is smaller than or equal to 40.8 J * kg <-1 > * K <-1 >. The extremely-low-temperature magnetic refrigeration material is rich in preparation raw materials, simple in process, free of rare earth elements, low in cost and suitable for industrial large-scale production.

This utility model discloses a permanent magnet circuit device and a rotary magnetic refrigerator. The permanent magnet circuit device includes a shaft, a stator, and a rotor; the rotor includes a housing, a first magnetic unit, and a second magnetic unit; the housing has a cylindrical structure; the housing is fitted over the stator, with a first accommodating space between them; the housing has an inner sidewall and an outer sidewall, with a second accommodating space between the inner and outer sidewalls for accommodating the first and second magnetic units; the first and second magnetic units are symmetrically arranged about the centerline of the shaft; the first magnetic unit includes n layers of magnets distributed radially along the housing, and the second magnetic unit includes n layers of magnets distributed radially along the housing, where n is a positive integer greater than or equal to 2; the n layers of magnets include a first layer and a second layer. The permanent magnet circuit device has a relatively large intermediate gap volume.

The invention discloses a rotary magnetic refrigeration component and magnetic refrigeration equipment. In the rotary magnetic refrigeration component, a plurality of inner ring magnets are the same in shape and size, each inner ring magnet is in a regular cylinder shape with an arc-shaped cross section, the inner ring magnets are arranged into a circular ring shape, and the adjacent inner ring magnets are tightly attached to each other; the outer ring magnets are the same in shape and size, each outer ring magnet is in a regular cylinder shape with an arc-shaped cross section, the outer ring magnets are arranged in a circular ring shape, and the adjacent outer ring magnets are tightly attached to each other; the multiple magnetic refrigeration beds are located between the multiple inner ring magnets and the multiple outer ring magnets, and the multiple magnetic refrigeration beds, the multiple inner ring magnets and the multiple outer ring magnets are equal in number and coaxial. The magnetization directions of the multiple inner ring magnets are alternately inward and outward in the radial direction, the magnetization directions of the multiple outer ring magnets are alternately inward and outward in the radial direction, and the plane where the joint of the adjacent inner ring magnets is located passes through the geometric center of the outer ring magnet on the outer side of the joint. And the magnetic refrigeration efficiency is high.