Efficient regenerative all-solid-state magnetic refrigeration device operating in single magnetic field and application of efficient regenerative all-solid-state magnetic refrigeration device

Abstract

The invention provides an efficient heat regeneration all-solid-state magnetic refrigeration device operating in a single magnetic field, which comprises at least one refrigeration unit, the refrigeration unit comprises a refrigeration layer and a heat regeneration layer which are arranged in parallel, and the refrigeration layer comprises a plurality of refrigeration sheets embedded in a first heat insulation material at intervals; the heat regeneration layer comprises a plurality of heat regeneration pieces embedded in a second heat insulation material, the refrigeration piece is equal to the heat regeneration piece plus 1, the refrigeration layer and the heat regeneration layer are made to do reciprocating translational motion during working through the arrangement of the refrigeration unit, and heat conduction exists between the refrigeration piece and the heat regeneration piece. The magnetic refrigeration device can operate in a single simple continuous magnetic field, the requirement for a magnet is reduced, the magnetic refrigeration device is more economical and environmentally friendly, the multiple heat regeneration pieces are used, heat conduction is conducted at the two moving terminals at the cold end and the hot end at the same time, the heat regeneration efficiency is greatly improved, and therefore the heat regeneration factor and the refrigeration power density are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic refrigeration, and relates to a reciprocating all-solid-state magnetic refrigeration device and its application which realizes efficient heat recovery by utilizing a single magnetic field without the assistance of a heat regenerator. Background Art

[0002] Magnetic refrigeration technology is a technology that achieves refrigeration through the entropy change and temperature change caused by the phase change of magnetic refrigeration materials during the process of applying and demagnetizing the magnetic field. In the process of traditional gas compression refrigeration, a large amount of refrigerant Freon is needed, which destroys the ozone layer and causes the greenhouse effect; while refrigerators using magnetic refrigeration technology do not produce and use chemicals that damage the environment, so magnetic refrigeration technology is a green and environmentally friendly technology.

[0003] On the other hand, compared with gas compression refrigeration, magnetic refrigeration is more efficient and energy-saving, can be miniaturized, and has no noise pollution. These advantages make magnetic refrigeration technology one of the ideal alternative technologies to traditional gas compression refrigeration.

[0004] The regenerators used in room temperature magnetic refrigerators can be divided into three types: external regenerators, internal regenerators, and active regenerators. The magnetic material in the active regenerator cycle (AMR) is both a magnetic refrigerant and a regenerator. By reducing the heat loss in the regenerator process, it has become the most recognized magnetic refrigeration cycle with the highest energy utilization efficiency at this stage, and has been used in many refrigerator cycles. The original traditional AMR cycle was completed by fluid heat exchange. However, in order to meet the characteristics of non-conductivity or non-magnetism, the heat exchange fluid often sacrifices its high thermal conductivity, limits the heat exchange speed, and limits the actual operating frequency of the refrigeration device to below 1Hz, thereby limiting its refrigeration power density. If the operating frequency is pursued blindly, it will cause insufficient heat conduction, thereby reducing the refrigeration power density and refrigeration efficiency of the system. On the other hand, the irreversible heat loss caused by the temperature difference between the heat transfer fluid and the wall, as well as the relatively rough mechanical control device of the fluid, have a non-negligible impact on the refrigeration efficiency of the device. In addition, the corrosion problem of the heat exchange fluid on the magnet and the refrigerant also brings difficulties to the design of magnetic refrigeration devices, thereby increasing the manufacturing cost of refrigeration devices.

[0005] In order to solve a series of problems caused by the traditional AMR based on fluid heat exchange, a new all-solid-state magnetic refrigeration model that regenerates heat through a solid heat exchange medium with high thermal conductivity has attracted great attention. There are two main types of all-solid-state refrigeration models reported so far, one is an all-solid-state magnetic refrigeration model based on thermal diodes (electrically controlled thermal diodes and magnetically controlled thermal diodes), and the other is an all-solid-state refrigeration model based on high thermal conductivity materials. Among them, in order to complete heat conduction faster, the all-solid-state magnetic refrigeration model based on thermal diodes with Peltier elements (electrically controlled thermal diodes) as solid heat conduction media needs to input a larger working current into the Peltier element, thereby increasing the electrical power loss of the entire system (that is, external work), resulting in a decrease in the COP (coefficient of refrigeration) of the entire refrigeration system and a decrease in refrigeration efficiency. If you choose to reduce the working current, you can indeed reduce the electrical power loss, but at the same time you also reduce the heat conduction speed, reduce the cooling capacity, and reduce the operating frequency, which goes against the original intention of introducing thermal diodes. Therefore, the introduction of Peltier elements can increase the operating frequency and cooling power of the all-solid-state magnetic refrigeration system, but at the same time it inevitably introduces electrical power loss, which has a negative impact on the cooling efficiency. On the other hand, although the all-solid-state refrigeration model based on magnetically controlled thermal diodes can greatly improve the power density, COP and refrigeration temperature span, it is difficult to obtain magnetically controlled thermal diode materials that meet the actual application conditions. In contrast, high thermal conductivity materials do not require external power drive to achieve efficient heat conduction, and high thermal conductivity materials are convenient and easy to obtain. Therefore, all-solid-state magnetic refrigeration devices that use high thermal conductivity materials for heat recovery can not only improve the refrigeration power and efficiency of refrigeration devices, but can also be truly built and put into practical use.

[0006] The applicant proposed an all-solid-state magnetic refrigeration device in another prior application CN202210515054.6, which has not yet been made public. The core refrigeration unit of the device includes multiple magnetic refrigeration plates and a heat conductive plate. The heat conductive plate contacts each of the multiple magnetic refrigeration plates in turn to achieve heat conduction. By establishing a finite element simulation model, it is calculated that the maximum heat recovery factor of the device is approximately 3. Summary of the invention

[0007] Therefore, the purpose of the present invention is to design and develop an all-solid-state magnetic refrigeration device with high efficiency and heat recovery operating under a single magnetic field. When a single magnet is used to generate a simple continuous magnetic field, the advantages of high thermal conductivity materials and fast thermal conductivity are utilized to achieve high-frequency operation while having a simple device design and lower processing and production costs. The heat recovery factor is better than the device proposed by the inventor in the previous design CN202210515054.6.

[0008] Among them, the heat recovery factor is defined as the ratio of the temperature span of the hot and cold ends when the device reaches equilibrium (equilibrium temperature span) to the temperature change (adiabatic temperature change) when the magnetic refrigerant enters and exits the magnetic field.

[0009] The “efficient heat recovery” mentioned in the present invention means that the heat recovery efficiency of the device of the present invention is higher than that of the device proposed by the inventor in CN202210515054.6 designed previously.

[0010] The inventor of the present invention has found through long-term literature accumulation and in-depth research that materials with high thermal conductivity such as copper, silver, gold, aluminum, platinum, iron, graphene, diamond aluminum alloy or carbon nanotubes can absorb or release heat in a relatively short time, and are a type of ideal heat recovery medium; on the other hand, insulation materials such as glass fiber, asbestos, rock wool, silicate, aerogel felt, vacuum plate, etc. can effectively prevent magnetic refrigeration medium and high thermal conductivity material from exchanging heat with the outside world, thereby reducing heat loss. Therefore, the inventor combines high thermal conductivity materials as heat recovery medium with magnetic refrigeration materials and insulation materials, and realizes efficient heat recovery of all-solid-state magnetic refrigeration through reasonable device design. In addition, since the magnetic refrigeration medium, heat recovery medium, and insulation material are all solid, it is easy to design and process them into different shapes and sizes, and it is also convenient for precise control of mechanical devices. Therefore, the all-solid-state refrigeration device based on high thermal conductivity materials can realize device refrigeration of different scales (submicron-meter).

[0011] The purpose of the present invention is achieved through the following technical solutions.

[0012] The present invention provides a high-efficiency heat-recovery all-solid-state magnetic refrigeration device operating in a single magnetic field, the magnetic refrigeration device comprising at least one refrigeration unit, the refrigeration unit comprising a refrigeration layer and a heat-recovery layer arranged in parallel, wherein:

[0013] - the refrigeration layer comprises a plurality of magnetic refrigeration medium sheets (also referred to as "refrigeration medium sheets" or "refrigeration sheets" in the present invention) embedded in the first thermal insulation material at intervals;

[0014] - the heat recovery layer comprises a plurality of heat recovery medium sheets (also referred to as "heat recovery sheets" in the present invention) embedded in the second heat insulation material,

[0015] Among them, the number of magnetic refrigeration working medium sheets = the number of regenerative working medium sheets + 1, the setting of the refrigeration unit enables the refrigeration layer and the regenerative layer to perform reciprocating translational motion respectively during operation, and there is heat conduction between the magnetic refrigeration working medium sheets and the regenerative working medium sheets.

[0016] In an embodiment of the present invention, the refrigeration unit is arranged so that each of the refrigeration fins only conducts heat to two adjacent heat return fins at its relative position during the reciprocating translational motion; similarly, each of the heat return fins only conducts heat to two adjacent refrigeration fins at its relative position during the reciprocating translational motion.

[0017] In a preferred embodiment of the present invention, the size of the refrigeration layer is equal to that of the heat recovery layer; and the size of the magnetic refrigeration working medium sheet is equal to that of the heat recovery working medium sheet.

[0018] In actual use, the two ends of the magnetic refrigeration device provided by the present invention cooperate with the cold end that needs to be refrigerated and the hot end for heat dissipation respectively. The cold end and the hot end are respectively located at the two movement terminals of the reciprocating translational motion of the device, and at the two movement terminals, heat is exchanged with the two outermost ones of the multiple magnetic refrigeration working medium sheets respectively.

[0019] In order to facilitate the explanation of the refrigeration capacity of the magnetic refrigeration device of the present invention, the hot and cold ends are set as pieces of high thermal conductivity material that remain stationary and are located at the two moving ends.

[0020] According to the magnetic refrigeration device provided by the present invention, during operation, a portion of the area spanned by the reciprocating motion of the magnetic refrigeration device is placed in a simple continuous magnetic field, preferably 40% to 70% of the area spanned by the reciprocating motion of the magnetic refrigeration device is placed in the magnetic field, and more preferably 45% to 55% of the area spanned by the reciprocating motion of the magnetic refrigeration device is placed in the magnetic field; in a most preferred embodiment, half (i.e., 50%) of the area spanned by the reciprocating motion of the magnetic refrigeration device is placed in the magnetic field.

[0021] The magnetic field may be a common continuous magnetic field. In the most preferred case, the magnetic field is set so that in one terminal state of the reciprocating translational motion of the cooling layer, the plurality of cooling plates are in the magnetic field, and in another terminal state, the plurality of cooling plates are outside the magnetic field.

[0022] Figure 1 A schematic diagram of the four working states of the magnetic refrigeration device of the present invention is drawn. In the reciprocating refrigeration cycle, each of the multiple refrigeration plates of the refrigeration layer is in the magnetic field area and the non-magnetic field area, and each refrigeration plate is in contact with the cold end or the left heat recovery plate when the temperature is reduced in the non-magnetic field area, and is in contact with the hot end or the right heat recovery plate when the temperature is increased in the magnetic field area, thereby absorbing heat from the cold end or the left heat recovery plate, and transferring heat to the hot end or the right heat recovery plate, so that heat is continuously transferred from the cold end to the hot end to achieve refrigeration.

[0023] The continuous magnetic field is preferably a uniform magnetic field, and the strength of the magnetic field can be 0.1 to 60 T, preferably 0.5 to 3 T. The frequency of the reciprocating motion of the refrigeration layer and the regenerative layer can be 0.01 to 1000 Hz, preferably 1 to 20 Hz. In a preferred case, the reciprocating motion frequencies of the refrigeration layer and the regenerative layer are the same.

[0024] According to the magnetic refrigeration device provided by the present invention, the magnetic refrigeration working medium sheet can be made of any magnetocaloric material, for example, it can be selected from one or more of Gd, FeRh, LaFeSi, GdSiGe, MnAs, MnPSiGe and NiMnX, preferably Gd, Gd5(Si,Ge)4, La(Fe,Si) 13 , MnCoGe and NiMnSn.

[0025] According to the magnetic refrigeration device provided by the present invention, the heat recovery medium sheet can be composed of any high thermal conductivity material, such as copper, silver, gold, aluminum, platinum, iron, graphene, diamond aluminum alloy and carbon nanotubes, etc., preferably copper, graphene and other readily available materials.

[0026] After in-depth research, the inventors found that the thickness of the heat recovery medium sheet has a relatively obvious effect on the temperature span after multiple cycles. When the thickness of the heat recovery medium sheet is too thin, the heat carrying capacity is too small, resulting in a decrease in the heat transported in each cycle, causing the temperature span to decrease; and when the heat recovery medium sheet is too thick, the heat conduction is not complete during each heat recovery process, causing the temperature span to decrease. Therefore, the thickness of the heat recovery medium sheet is closely related to the thickness of the refrigeration medium sheet, the operating frequency and the type of material. In a preferred embodiment of the present invention, the ratio of the thickness of the heat recovery medium sheet to the thickness of the refrigeration medium sheet is 0.5 to 3:1.

[0027] According to the high-efficiency heat-recovery reciprocating all-solid-state magnetic refrigeration device provided by the present invention, the first insulation material and the second insulation material may be the same or different, and may each be independently selected from one or more of glass fiber, asbestos, rock wool, silicate, aerogel felt and vacuum panel.

[0028] According to the high-efficiency reciprocating all-solid-state magnetic refrigeration device with heat recovery provided by the present invention, the refrigeration sheet can be embedded in the first heat insulating material of the refrigeration layer or the heat recovery sheet can be embedded in the second heat insulating material of the heat recovery layer by any known method, such as bonding with epoxy resin. The refrigeration layer and the heat recovery layer can be assembled together by any known method, as long as the refrigeration layer and the heat recovery layer can independently perform translational motion, for example, the heat recovery layer and the refrigeration layer can be independently controlled by a linear stepping motor.

[0029] In a preferred embodiment of the present invention, in order to achieve optimal heat conduction between the refrigeration layer and the heat recovery layer and reduce the additional loss caused by frictional work, graphite powder or other heat conductive material powder is arranged between the refrigeration layer and the heat recovery layer. Preferably, the distance between the refrigeration layer and the heat recovery layer can be 0 to 10 nm.

[0030] In some preferred embodiments of the present invention, the size of the refrigeration fins, the size of the heat recovery fins, the size of the first insulation material between two adjacent refrigeration fins, and the size of the second insulation material between two adjacent heat recovery fins are of the same order of magnitude. In a more preferred embodiment, the size of the refrigeration fins, the size of the heat recovery fins, the size of the first insulation material between two adjacent refrigeration fins, and the size of the second insulation material between two adjacent heat recovery fins are equal.

[0031] According to the magnetic refrigeration device provided by the present invention, the magnetic refrigeration device may include a refrigeration array composed of a plurality of refrigeration units, wherein the plurality of refrigeration units are stacked up and down to form a structure in which a refrigeration layer and a heat recovery layer are overlapped and arranged. The number of refrigeration units included in the refrigeration array can be selected to be 1 to 100, for example, 2 to 100, preferably 2 to 25, according to actual refrigeration needs.

[0032] In the refrigeration array stacked up and down, the refrigeration layers and the heat recovery layers are arranged alternately, that is, the two layers adjacent to each refrigeration layer are both heat recovery layers, and the two layers adjacent to each heat recovery layer are both refrigeration layers. The number of heat recovery layers can be equal to the refrigeration layers, or one more or one less than the refrigeration layers. In addition, the number of refrigeration plates in each refrigeration layer is the same, and the number of heat recovery plates in each heat recovery layer is the same. More preferably, the heat recovery layer has one more layer than the refrigeration layer, so that each refrigeration layer is in contact with two heat recovery layers at the same time, further improving the heat recovery efficiency.

[0033] The present invention has no special restrictions on the shapes of the refrigeration layer, heat recovery layer, refrigeration fins and heat recovery fins. In a preferred embodiment, in order to facilitate manufacturing and control the heat recovery effect, the refrigeration layer and the heat recovery layer, refrigeration fins and heat recovery fins are all rectangular with the same size. Preferably, the multiple refrigeration fins are embedded in the first insulation material of the refrigeration layer at equal intervals, and the heat recovery fins are embedded in the second insulation material of the heat recovery layer at the same intervals. Among them, the refrigeration layer preferably includes 2 to 100 magnetic refrigeration working fluid sheets, more preferably 4 to 25; the number of heat recovery fins in the heat recovery layer is always 1 less than the number of refrigeration fins in the refrigeration layer.

[0034] On the other hand, the present invention also provides the application of the above-mentioned high-efficiency heat recovery reciprocating all-solid-state magnetic refrigeration device in refrigerators, air conditioners, liquefied gases and microelectronic device refrigeration.

[0035] The application includes placing the highly efficient heat-regenerating reciprocating all-solid-state magnetic refrigeration device in a common continuous magnetic field, so that the multiple refrigeration plates of the refrigeration layer are in the magnetic field in one terminal state of the reciprocating translational motion, and the multiple refrigeration plates are outside the magnetic field in another terminal state. Preferably, the intensity of the magnetic field is 0.1 to 60 T, more preferably 0.5 T to 3 T. The frequency of the reciprocating translational motion of the refrigeration layer and the heat-regenerating layer is the same, preferably 0.01 to 1000 Hz, more preferably 0.1 to 20 Hz.

[0036] In a preferred embodiment of the present invention, the application includes matching the magnetic refrigeration device with a cold end that needs to be refrigerated and a hot end that performs heat dissipation, wherein the cold end and the hot end are respectively located at two movement terminals of the reciprocating translational motion of the magnetic refrigeration device, and heat is exchanged with the two outermost ones of the plurality of magnetic refrigeration working medium sheets at the two movement terminals, respectively.

[0037] Wherein, when the cold end is located on the left and the hot end is located on the right, the application includes: starting from the hot end on the right, placing 40% to 70% of the area spanned by the reciprocating motion of the magnetic refrigeration device in the magnetic field, and operating according to the following timing:

[0038] (1) The refrigeration layer and the heat recovery layer are stationary at the cold end movement terminal, wherein each refrigeration medium sheet is in thermal contact with the heat recovery medium sheet on the left side and the cold end, respectively, and absorbs heat from the cold end and the heat recovery medium sheet on the left side;

[0039] (2) The cooling layer and the regenerative layer move toward the hot end and enter the magnetic field at the same time. The cooling layer moves faster than the regenerative layer. The cooling medium sheet enters the magnetic field after leaving the cold end and the regenerative medium sheet on the left and before contacting the regenerative medium sheet on the right and the hot end to complete the heating process.

[0040] (3) After entering the magnetic field, the cooling layer and the heat recovery layer are stationary at the hot end movement terminal, wherein each cooling medium sheet is in thermal contact with the right heat recovery sheet and the hot end, respectively, and releases heat to the hot end and the right heat recovery sheet;

[0041] (4) The cooling layer and the regenerative layer move toward the cold end and leave the magnetic field at the same time. The cooling layer moves faster than the regenerative layer. The refrigerant sheet completes the cooling process out of the magnetic field after leaving the hot end and the right regenerative sheet and before contacting the left regenerative sheet and the cold end.

[0042] (5) According to the order of (1)-(4), the above operations are switched back and forth, so as to transport heat from the cold end to the hot end to achieve refrigeration;

[0043] Alternatively, the application includes operating in the following sequence: the cooling layer and the heat recovery layer first enter the magnetic field and stop at the moving terminal described in (3). After cooling to room temperature and completing initialization, the above operations are switched back and forth in the order of (3)-(4)-(1)-(2) to transport heat from the cold end to the hot end to achieve cooling.

[0044] For simplicity, a magnetic refrigeration device having a refrigeration unit, i.e., a refrigeration layer and a heat recovery layer, is taken as an example. Figure 1 The preferred working mode and working principle of the device of the present invention are described.

[0045] 1) Before the device is operated, as shown in Figure (a), the cooling layer and the regenerative layer both stay at the moving terminal outside the magnetic field. At this time, the cooling plate on the far left of the cooling layer maintains good thermal contact with the cold end, and the other cooling plates maintain good thermal contact with the regenerative plate on the left. The multiple cooling plates and the regenerative plates are separated by insulating materials to maintain thermal insulation. During operation, the cooling layer and the regenerative layer will perform reciprocating translational motion separately in a certain time sequence.

[0046] 2) A single continuous magnetic field is applied by a common permanent magnet or an electromagnet. The magnetic field region is constant and is set on the side close to the hot end. The magnetic field region is preferably of a length that can just accommodate all the cooling plates at the same time. In one terminal state, multiple cooling plates are in the magnetic field, and in another terminal state, the cooling plates are outside the magnetic field.

[0047] 3) Since the multiple refrigeration fins of the refrigeration layer and the multiple heat recovery fins of the heat recovery layer are separated by insulating materials, there is no heat transfer between the multiple refrigeration fins and the multiple heat recovery fins, and heat transfer only exists between the refrigeration layer and the heat recovery layer and between the refrigeration layer and the cold and hot ends.

[0048] 4) The cold end and the hot end are respectively arranged at the two moving terminals of the refrigeration layer. Figure 1 Figure (a) shows the first terminal state and the first working state during the operation of the device. At this time, each cooling plate in the cooling layer maintains good thermal contact with the cold end and the left heat recovery plate in the corresponding heat recovery layer. Figure 1 Figure (b) shows the second working state of the device during operation. At this time, the cooling layer and the heat recovery layer move to the right at the same time and enter the magnetic field. The cooling layer moves faster than the heat recovery layer, so that the cooling plate in the cooling layer begins to enter the magnetic field to heat up after leaving the cold end and the heat recovery plate on the left, and completes the heating process before contacting the hot end and the heat recovery plate on the right. There is no special limitation on the specific movement process, as long as the two conditions are met: the cooling plate in the cooling layer enters the magnetic field to heat up after leaving the cold end and the heat recovery plate on the left, and completes the heating process before contacting the hot end and the heat recovery plate on the right. Figure 1Figure (c) shows another moving terminal during the operation of the device, which is also the third working state. At this time, the cooling layer and the heat recovery layer remain stationary, and each cooling plate in the cooling layer maintains good thermal contact with the hot end and the heat recovery plate on the right, respectively, transferring heat to the hot end and the heat recovery plate on the right. Figure 1 Figure (d) shows the fourth working state of the device during operation. The cooling layer and the heat recovery layer simultaneously move to the left out of the magnetic field. The cooling plate of the cooling layer goes out of the magnetic field to cool down after leaving the hot end and the heat recovery plate on the right, and completes the cooling process before contacting the cold end and the heat recovery plate on the left. There is no special limitation on the movement process, as long as the two conditions are met: the cooling plate of the cooling layer goes out of the magnetic field to cool down after leaving the hot end and the heat recovery plate on the right, and completes the cooling process before contacting the cold end and the heat recovery plate on the left. Finally, the device returns to the state of cooling again. Figure 1 In the terminal shown in Figure (a), the cooling plate absorbs heat from the cold end and the heat recovery plate on the left after cooling, and the heat is continuously transported from the cold end on the left to the hot end on the right to achieve cooling. The device can also enter the magnetic field first, cool down to room temperature to complete initialization, and then start from the third working state and operate according to the above working sequence to complete cooling.

[0049] 5) In actual use, the cold end and hot end in the device schematic diagram can be the substance to be cooled and the surrounding room temperature environment respectively. The device absorbs heat from the substance to be cooled (i.e., cools the cold end) and releases heat to the surrounding environment to achieve cooling.

[0050] 6) During the reciprocating motion of the refrigeration layer and the heat recovery layer, the heat at the cold end is transferred to the hot end through the heat recovery fins with high thermal conductivity. Since the multiple refrigeration fins in the refrigeration layer and the multiple heat recovery fins in the heat recovery layer are insulated from each other, a temperature gradient is formed between the refrigeration fins and the heat recovery fins. By increasing the number of refrigeration fins and heat recovery fins, a cascade-like effect can be achieved, thereby increasing the temperature span.

[0051] 7) Taking advantage of the high thermal conductivity of the heat recovery layer and the design of multiple heat recovery plates to simultaneously recover heat at two moving terminals, the all-solid-state magnetic refrigeration device achieves high heat recovery efficiency, thereby realizing high-frequency and high-efficiency refrigeration.

[0052] Compared with the applicant's prior patent application CN202110906753.9, the prior application requires multiple magnets to generate multiple continuous magnetic fields; while the present invention only requires one magnet, that is, under a simple continuous magnetic field, it can achieve efficient operation with a heat recovery factor greater than 1, which greatly reduces the requirements for magnets and reduces production costs.

[0053] On the other hand, compared with the applicant's prior patent application CN202210515054.6, the device proposed in the prior application has only one heat recovery plate, which makes the heat recovery efficiency low, thereby limiting the heat recovery factor and cooling power; while the present invention uses multiple heat recovery plates, and at the two moving terminals of the hot and cold ends, multiple heat recovery plates simultaneously conduct heat, which greatly improves the heat recovery efficiency, thereby improving the heat recovery factor and cooling power, and is more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0055] Figure 1 Schematic diagram of four working states of the magnetic refrigeration device of the present invention;

[0056] Figure 2 This is a schematic diagram of the mesh division model of the magnetic refrigeration device of the present invention using rectangular cooling plates and heat recovery plates for finite element simulation in an embodiment.

[0057] Figure 3 It is a temperature schematic diagram when each refrigeration plate and the cold and hot ends of the magnetic refrigeration device in the embodiment reach thermal equilibrium;

[0058] Figure 4 This is a data diagram showing the effect of Cu thickness on the heat recovery factor in the magnetic refrigeration device of the present invention;

[0059] Figure 5 This is a data graph showing the effect of Cu thickness on the temperature span after 20 cycles in the magnetic refrigeration device of the present invention;

[0060] Figure 6 A data diagram showing the effect of the operating frequency on the regenerative heat factor in the magnetic refrigeration device of the present invention;

[0061] Figure 7 This is a data diagram showing the effect of the number of Gd refrigeration chips on the heat recovery factor in the magnetic refrigeration device of the present invention;

[0062] Figure 8 This is a relationship diagram between the refrigeration power and the equilibrium temperature span in the magnetic refrigeration device of the present invention. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below in conjunction with specific embodiments. The given examples are only for illustrating the present invention, but not for limiting the scope of the present invention.

[0064] Figure 1 Figures (a) to (d) are schematic diagrams of two moving terminals and four working stages of the magnetic refrigeration device of the present invention used in the embodiment.

[0065] The magnetic refrigeration device can work under a simple continuous magnetic field generated by a single magnet, and includes a refrigeration unit, wherein the refrigeration unit includes a rectangular refrigeration layer and a rectangular heat recovery layer, wherein the rectangular refrigeration layer includes a plurality of rectangular refrigeration sheets and a heat insulating material connecting them together, and the rectangular heat recovery layer includes a plurality of rectangular heat recovery sheets and a heat insulating material connecting them together, and the number of the heat recovery sheets is one less than the number of refrigeration sheets. The rectangular refrigeration layer and the rectangular heat recovery layer can move in a certain direction in sequence. Half of the area close to the hot end of the area spanned by the reciprocating motion of the all-solid-state magnetic refrigeration device is placed in a magnetic field.

[0066] In the embodiment, finite element simulation is used to calculate the equilibrium temperature span and refrigeration efficiency of the magnetic refrigeration device designed in the present invention during operation. The specific parameters are described as follows:

[0067] 1) In the region from the cold end to the hot end (i.e., the region across which the device reciprocates), a simple continuous magnetic field generated by a single magnet is applied to the half of the region close to the hot end.

[0068] 2) Both the cooling layer and the heat recovery layer are rectangular, and the total length of the device is 0.5mm to 10000mm, preferably 5 to 200mm. The cooling plate and the heat recovery plate are of equal size, and the length and width are independently 0.1mm to 100mm, preferably 1mm to 10mm. The thickness of each layer is selected according to actual needs, and can be selected to be 0.01mm to 50mm, preferably 0.1 to 5mm.

[0069] 3) In a refrigeration array formed by stacking multiple core refrigeration units, the refrigeration layers and the heat recovery layers are arranged alternately from top to bottom. Each core refrigeration unit is composed of two layers (a refrigeration layer and a heat recovery layer). The number of core refrigeration units stacked up and down can be selected to be 1 to 100 according to actual refrigeration needs, that is, 2 to 200 layers. The preferred number of core refrigeration units stacked up and down is 2 to 25, that is, 4 to 50 layers. In order to achieve the alternating stacking setting, the number of the rectangular refrigeration layers is within the range of ±1 of the rectangular heat recovery layers. Preferably, the number of the rectangular refrigeration layers is 1 less than the number of the rectangular heat recovery layers.

[0070] 4) There are 2 to 100 refrigeration plates in the refrigeration layer, and the number of heat recovery plates in the heat recovery layer is one less than the number of refrigeration plates.

[0071] 5) Adiabatic module, which uses adiabatic boundaries instead in the simulation.

[0072] 6) The adiabatic temperature change generated when the cooling plate enters and moves out of the magnetic field is selected to be 0.1~20K.

[0073] 7) The software used for finite element simulation is the solid heat transfer module in COMSOL Multiphysics 5.6.

[0074] 8) According to the actual cooling requirements, the initial temperature of the cooling layer and the heat recovery layer is set to 0.1K~1000K.

[0075] A representative example is given below to illustrate the simulation method of the magnetic refrigeration device of the present invention:

[0076] 1) The refrigeration unit in the model is composed of a simple composite of a refrigeration layer and a heat recovery layer. The number of rectangular refrigeration plates in the refrigeration layer is set to 4, and the number of rectangular heat recovery plates in the heat recovery layer is set to 3. The length and width of the refrigeration plates and the heat recovery plates are the same, which are 5 mm and 3 mm respectively. The geometric model is as follows: Figure 1 , two motion terminals and four motion steps as follows Figure 1 The initial temperatures of the cooling layer and the regenerative layer are both set to 295K, and the hot and cold ends are located at the two moving ends of the cooling layer. When the cooling layer moves to the right end and enters the continuous magnetic field, the temperature will increase by 4K. Similarly, when the cooling layer moves to the left end and moves out of the continuous magnetic field, the temperature will decrease by 4K.

[0077] 2) Among them, heat exchange can only be carried out when the cooling plate contacts the heat recovery plate and the hot and cold ends, and the other boundaries are adiabatic boundaries. In order to describe the translational reciprocating motion of the upper cooling layer and the lower heat recovery layer, the dynamic mesh boundary conditions are defined in the model, and the upper cooling layer and the lower heat recovery layer are set to reciprocate with a period of 1s (frequency of 1Hz), a total of 100 cycles, and a total calculation time domain of 100s.

[0078] 3) This model uses tetrahedral units for free meshing. The mesh model is as follows: Figure 2 shown.

[0079] 4) This model adopts transient solution, the calculation time domain is 1s as a cycle, the time step does not exceed 0.002s, the total time is 100s, and the direct strong coupling solver is used for solution, combined with the nonlinear Newton iteration method, and the convergence factor is 0.01.

[0080] 5) Based on the finite element simulation model established above, by setting and calculating the initial parameters, with continuous cycles, the temperature difference distribution of the cooling plate, heat recovery plate and hot and cold ends in the device gradually stabilizes. In order to more clearly see the temperature change of the magnetic refrigeration device over time, the temperature change curves of the hot and cold ends and each cooling plate after stabilization are shown in Figure 3In the figure, the upper and lower horizontal lines are the hot end and the cold end respectively, and the four fluctuating curves in the middle correspond to the four cooling plates from right to left from top to bottom. The figure shows the result when the thickness of the cooling plate Gd is 1mm and the thickness of the heat recovery plate Cu is 1.4mm. The hot end temperature is stable at about 303.7K, and the cold end temperature is stable at about 287.3K. The 16.4K temperature span formed corresponds to the four cooling plates. When the adiabatic temperature of the cooling plate changes to 4K, the maximum temperature span of the device without load, and its heat recovery factor is 4.1, which is much larger than 1.

[0081] 6) Based on the finite element simulation model established above, the heat recovery factor of the device was calculated when the thermal conductive material Cu had different thicknesses of 0.7-1.9 mm. The heat recovery factor is defined as the ratio of the equilibrium temperature span to the adiabatic temperature change of the cooling plate, such as Figure 4 It can be seen that the thickness of Cu has little effect on the heat recovery factor, which is around 4, indicating that the size of the heat recovery factor of the device does not depend on the thickness of the heat recovery sheet.

[0082] 7) Based on the finite element simulation model established above, the temperature span of the hot and cold ends of the device after 20 cycles of operation was calculated when the thermal conductive material Cu had different thicknesses of 0.7-1.9 mm, as shown in Figure 2. Figure 5 As shown. It can be seen that the thickness of Cu has a relatively obvious effect on the temperature span of the device after 20 cycles. When the thickness of Cu is too thin, the ability of the Cu sheet to carry heat is too small, resulting in a decrease in the amount of heat transported in each cycle, causing the temperature span to decrease; and when Cu is too thick, the heat conduction of the Cu sheet is not complete during each heat recovery process, causing the temperature span to decrease. Therefore, when the thickness of the cooling sheet is fixed, the heat recovery sheet should have an optimal thickness, and the optimal thickness of the Cu sheet here is 1.4mm. In summary, the thickness of the heat recovery layer will not affect the heat recovery factor, but it will affect the rate of heat transfer, that is, it will affect the cooling power and cooling efficiency of the device. Therefore, in the actual cooling process, the thickness of the heat recovery layer should be selected as the optimal thickness.

[0083] 8) Based on the finite element simulation model established above, the heat recovery factor of the device at different operating frequencies was calculated, such as Figure 6 The results show that when the thickness of Cu is fixed at 1.4 mm, the heat recovery factor remains basically unchanged at different frequencies, all around 4. This indicates that the heat recovery factor of the device does not depend on the operating frequency.

[0084] In the device proposed in the prior application CN202210515054.6, there is only one copper plate for heat recovery. Because its heat recovery speed is very slow, its heat recovery factor is highly dependent on frequency. There are also 4 Gd cooling plates of the same size, and their adiabatic temperature change is also 4K. The heat recovery factor is less than 2 at 1Hz, and the maximum heat recovery factor at 0.1Hz is only 3. In contrast, the design of multiple heat recovery plates in the present invention greatly improves its heat recovery speed, making its heat recovery factor not only independent of frequency, but also reaches 4 when there are 4 cooling plates, which is significantly higher than the previous device, proving that the design of the present invention effectively improves the heat recovery efficiency.

[0085] 9) Based on the finite element simulation model established above, the heat recovery factor of the device under different numbers of cooling plates is calculated, such as Figure 7 As shown. By fixing the thickness of Cu at 1.4 mm and changing the number of Gd sheets, it can be seen that the heat recovery factor and the number of Gd sheets show a good linear relationship, and the heat recovery factor is basically equal to the number of Gd sheets. In summary, the heat recovery factor of the device only depends on the number of cooling sheets, and has nothing to do with the thickness of the heat recovery layer and the operating frequency. In order to obtain a larger heat recovery factor, the number of cooling sheets can be appropriately increased.

[0086] 10) Based on the finite element simulation model established above, the thickness of Cu is fixed to 1.4 mm, the temperature of the hot end is fixed, and a load is added to the cold end to study the cooling capacity of the device, such as Figure 8 It can be seen that there is a good linear relationship between the cooling power and the equilibrium temperature span. At an operating frequency of 1 Hz, the maximum cooling power of the device exceeds 0.06 W.

[0087] The following specifically describes the composition, thickness, number of sheets, operating frequency, and adiabatic temperature change of the refrigerant and heat recovery medium used in the refrigeration unit in each embodiment, wherein the number of magnets used is 1.

[0088] Example 1

[0089] Cooling plate: Gd, heat recovery plate: Cu

[0090] The number of rectangular cooling plates in the cooling layer: 4; the number of rectangular heat recovery plates in the heat recovery layer: 3;

[0091] Thickness: Gd(1mm) / Cu(1.4mm)

[0092] Operating frequency: 1Hz

[0093] Adiabatic temperature change during Gd entering magnetic field: 4K

[0094] Example 2

[0095] Cooling plate: Gd, heat recovery plate: Cu

[0096] The number of rectangular cooling plates in the cooling layer: 4; the number of rectangular heat recovery plates in the heat recovery layer: 3;

[0097] Thickness: Gd(1mm) / Cu(0.9mm)

[0098] Operating frequency: 1Hz

[0099] Adiabatic temperature change during Gd entering magnetic field: 4K

[0100] Example 3

[0101] Cooling plate: Gd, heat recovery plate: Cu

[0102] The number of rectangular cooling plates in the cooling layer: 6; the number of rectangular heat recovery plates in the heat recovery layer: 5;

[0103] Thickness: Gd(1mm) / Cu(1.4mm)

[0104] Operating frequency: 1Hz

[0105] Adiabatic temperature change during Gd entering magnetic field: 4K

[0106] Example 4

[0107] Cooling plate: Gd, heat recovery plate: Cu

[0108] Number of rectangular cooling plates in each cooling layer: 4; Number of rectangular heat recovery plates in each heat recovery layer: 3; Thickness is Gd (1mm) / Cu (1.4mm)

[0109] Operating frequency: 0.1Hz

[0110] Adiabatic temperature change during Gd entering magnetic field: 4K

[0111] Example 5

[0112] Cooling plate: Gd, heat recovery plate: Cu

[0113] Number of rectangular cooling plates in each cooling layer: 5; Number of rectangular heat recovery plates in each heat recovery layer: 4;

[0114] Thickness: Gd(0.5mm) / Cu(1mm)

[0115] Operating frequency: 1Hz

[0116] Adiabatic temperature change during Gd entering magnetic field: 4K

[0117] Example 6

[0118] Cooling plate: FeRh, heat recovery plate: Ag

[0119] The number of rectangular cooling plates in the cooling layer: 2; the number of rectangular heat recovery plates in the heat recovery layer: 1;

[0120] Thickness: FeRh(0.01mm) / Ag(0.02mm)

[0121] Operating frequency: 0.01Hz

[0122] Adiabatic temperature change of FeRh during entering magnetic field: 5K

[0123] Example 7

[0124] Cooling plate: LaFeSi, heat recovery plate: Au

[0125] The number of rectangular cooling plates in the cooling layer: 5; the number of rectangular heat recovery plates in the heat recovery layer: 4;

[0126] Thickness: LaFeSi(0.02mm) / Au(0.05mm)

[0127] Operating frequency: 0.02Hz

[0128] Adiabatic temperature change of LaFeSi in the process of entering magnetic field: 6K

[0129] Example 8

[0130] Cooling plate: GdSiGe, heat recovery plate: Al

[0131] The number of rectangular cooling plates in the cooling layer: 10; the number of rectangular heat recovery plates in the heat recovery layer: 9;

[0132] Thickness: GdSiGe(0.05mm) / Al(0.1mm)

[0133] Operating frequency: 0.05Hz

[0134] Adiabatic temperature change of GdSiGe during entering magnetic field: 7K

[0135] Example 9

[0136] Cooling plate: MnAs, heat recovery plate: Pt

[0137] The number of rectangular cooling plates in the cooling layer: 20; the number of rectangular heat recovery plates in the heat recovery layer: 19;

[0138] Thickness: MnAs(0.1mm) / Pt(0.2mm)

[0139] Operating frequency: 0.2Hz

[0140] Adiabatic temperature change of MnAs entering magnetic field: 8K

[0141] Example 10

[0142] Cooling plate: MnPSiGe, heat recovery plate: Fe

[0143] The number of rectangular cooling plates in the cooling layer: 50; the number of rectangular heat recovery plates in the heat recovery layer: 49;

[0144] Thickness: MnPSiGe(0.2mm) / Fe(0.5mm)

[0145] Operating frequency: 0.5Hz

[0146] Adiabatic temperature change of MnPSiGe during entering magnetic field: 7K

[0147] Embodiment 11

[0148] Refrigeration sheet: NiMnSn, heat recovery sheet: graphene

[0149] The number of rectangular cooling plates in the cooling layer: 100; the number of rectangular heat recovery plates in the heat recovery layer: 99;

[0150] Thickness: NiMnSn (0.5mm) / graphene (1mm)

[0151] Operating frequency: 2Hz

[0152] Adiabatic temperature change of NiMnSn during entering magnetic field: 6K

[0153] Example 12

[0154] Refrigeration sheet: MnAs, heat recovery sheet: diamond aluminum alloy

[0155] The number of rectangular cooling plates in the cooling layer: 13; the number of rectangular heat recovery plates in the heat recovery layer: 12;

[0156] Thickness: MnAs (50mm) / diamond aluminum alloy (40mm)

[0157] Operating frequency: 5Hz

[0158] Adiabatic temperature change of MnAs entering magnetic field: 5K

[0159] Example 13

[0160] Refrigeration plate: FeRh, heat recovery plate: Fe

[0161] The number of rectangular cooling plates in the cooling layer: 24; the number of rectangular heat recovery plates in the heat recovery layer: 23;

[0162] Thickness: FeRh(2mm) / Fe(5mm)

[0163] Operating frequency: 10Hz

[0164] Adiabatic temperature change of FeRh during entering magnetic field: 4K

[0165] Embodiment 14

[0166] Refrigeration sheet: LaFeSi, heat recovery sheet: carbon nanotube

[0167] The number of rectangular cooling plates in the cooling layer: 35; the number of rectangular heat recovery plates in the heat recovery layer: 34;

[0168] Thickness: LaFeSi (5mm) / carbon nanotube (10mm)

[0169] Operating frequency: 1000Hz

[0170] Adiabatic temperature change of LaFeSi in the process of entering magnetic field: 3K

[0171] Embodiment 15

[0172] Refrigeration sheet: Gd, heat recovery sheet: graphene

[0173] The number of rectangular cooling plates in the cooling layer: 67; the number of rectangular heat recovery plates in the heat recovery layer: 66;

[0174] Thickness: Gd(10mm) / graphene(20mm)

[0175] Operating frequency: 50Hz

[0176] Adiabatic temperature change of Gd entering magnetic field: 8K

[0177] Example 16

[0178] Refrigeration sheet: Gd, heat recovery sheet: Ag

[0179] The number of rectangular cooling plates in the cooling layer: 73; the number of rectangular heat recovery plates in the heat recovery layer: 72;

[0180] Thickness: Gd(20mm) / Ag(50mm)

[0181] Operating frequency: 100Hz

[0182] Adiabatic temperature change of Gd entering magnetic field: 7K

[0183] Embodiment 17

[0184] Cooling plate: GdSiGe, heat recovery plate: carbon nanotube

[0185] The number of rectangular cooling plates in the cooling layer: 85; the number of rectangular heat recovery plates in the heat recovery layer: 84;

[0186] Thickness: GdSiGe (0.02mm) / carbon nanotube (0.01mm)

[0187] Operating frequency: 500Hz

[0188] Adiabatic temperature change of GdSiGe during entering magnetic field: 6K

[0189] Refrigeration performance simulation results

[0190] Examples 1 to 17 all show good refrigeration effects. The following is an exemplary example of the simulation effects of Examples 1 to 4.

[0191] 1) No-load cooling temperature span

[0192] In Examples 1-3, it is assumed that the simple continuous magnetic field generated by a single magnet occupies half of the area spanned by the reciprocating motion of the device, there are three rectangular heat conduction modules and four rectangular cooling modules, and the geometric model thereof is as follows: Figure 1 As shown. The initial temperature of all refrigeration layers and heat recovery layers is set to 295K, and the cold end and the hot end are separated at the two moving terminals of the refrigeration layer. Among them, the temperature of the refrigeration module will increase by 4K when it enters the magnetic field area, and the temperature of the refrigeration module will decrease by 4K when it leaves the magnetic field area. As the refrigeration layer and the heat recovery layer reciprocate in sequence, the refrigeration plate and the heat recovery plate and the cold and hot ends are in contact at the two moving terminals for heat exchange, resulting in the temperature of each refrigeration module and the heat recovery module constantly changing. As the cycle proceeds, the temperature eventually reaches stability. The temperature difference between the hot end and the cold end when the steady state is reached is the maximum temperature span of the efficient heat recovery all-solid-state magnetic refrigeration model device under no-load conditions. Based on the finite element simulation model established above, by setting and calculating the initial parameters, with continuous cycles, the temperature distribution of the refrigerant gradually tends to be stable. In order to more clearly see the temperature changes of the cold and hot ends and each refrigeration plate when stable, the temperature change curve of Example 1 over time when stable is shown in Figure 3In the figure, the upper and lower horizontal lines are the hot end and the cold end respectively, and the four fluctuating curves in the middle correspond to the four cooling plates from right to left from top to bottom. It can be seen that the hot end temperature is stable at about 303.7K, and the cold end temperature is stable at about 287.3K. The 16.4K temperature span formed corresponds to the four cooling plates, that is, the maximum no-load temperature span of the device when the adiabatic temperature change of the cooling plate is 4K, which proves that the all-solid-state magnetic refrigeration model device designed by the present invention can form a large refrigeration temperature span under limited adiabatic temperature change. The regenerative factor is defined as the ratio of the equilibrium temperature span to the adiabatic temperature change. Here, the regenerative factor corresponding to the four cooling plates is 16.4K / 4K=4.1, which is not only much higher than 1, but also greater than the maximum regenerative factor 3 obtained at a working frequency of 0.1Hz in the prior application CN202210515054.6, proving that the design of the present invention greatly improves the regenerative efficiency of the device.

[0193] 2) Effect of heat recovery layer thickness on heat recovery factor and refrigeration capacity

[0194] In order to study the effect of the thickness of the heat recovery layer on the heat recovery factor, based on the finite element simulation model established above, the heat recovery factor of the device in Example 1 was calculated under different heat transfer layer Cu thicknesses of 0.7 to 1.9 mm. Figure 4 As shown. It can be seen that the thickness of the heat exchanger has almost no effect on the cooling factor of the device, proving that the heat exchanger factor of the device does not depend on the thickness of the heat exchanger. In order to further verify the effect of the thickness of the heat exchanger on the cooling capacity of the device, Figure 5 The effect of different Cu sheet thicknesses on the temperature difference between the hot and cold ends after 20 cycles is shown. It can be seen that when the heat recovery layer is too thin, the heat carrying capacity of the heat recovery layer is too weak, and the heat transported in each cycle is too little, which reduces the temperature difference between the hot and cold ends; and when the heat recovery layer is too thick, the heat exchange between the heat recovery layer and the cooling layer at the two terminals is incomplete, and thermal equilibrium is not reached, which reduces the heat transported in each cycle, resulting in a decrease in the temperature difference between the hot and cold ends. Therefore, the thickness of the heat recovery layer has no effect on the heat recovery factor of the device, but has a significant effect on the cooling capacity of the device.

[0195] 3) The influence of operating frequency on the heat recovery factor

[0196] In order to study the influence of the device operating frequency on the balanced temperature span, the number of refrigeration modules N established in the above embodiment 1 is S =4 (very easy to manufacture), ΔT MCE =4K (easily obtained by permanent magnets) when the thickness of the heat recovery layer Cu is set to 1.4mm and the operating frequency is changed. Figure 6 It can be seen that with the increase of the operating frequency, the regenerative factor does not change significantly and is always around 4. Therefore, it can be concluded that the regenerative factor of the device does not depend on the operating frequency.

[0197] 3) The influence of the number of refrigeration units on the heat recovery factor

[0198] In order to study the effect of the number of cooling plates on the equilibrium temperature span in the magnetic refrigeration device of the present invention, based on the above-mentioned Example 1, the thickness of the heat recovery layer is 1.4 mm, ΔT MCE =4K finite element simulation model, set the working frequency to 1Hz, change the number of cooling plates, and study the effect of the number of cooling plates on the heat recovery factor. Figure 7 It can be seen that the heat recovery factor has a good linear relationship with the number of cooling plates, and the size of the heat recovery factor is basically equal to the number of cooling plates. In summary, the heat recovery factor of the device has nothing to do with the thickness of the heat recovery layer and the operating frequency, but only depends on the number of cooling plates. In the prior application CN202210515054.6, there is only one copper plate for heat recovery, and because its heat recovery speed is very slow, its heat recovery factor is highly dependent on the frequency. There are also 4 Gd cooling plates of the same size, and their adiabatic temperature change is also 4K. The heat recovery factor is less than 2 at 1Hz, and the maximum heat recovery factor at 0.1Hz is only 3. In contrast, the design of multiple heat recovery plates in the present invention greatly improves its heat recovery speed, so that its heat recovery factor is not only independent of frequency, but also reaches 4 when there are 4 cooling plates, which is significantly higher than the prior application, proving that the design of the present invention effectively improves the heat recovery efficiency.

[0199] 4) Temperature span with load cooling

[0200] In order to study the refrigeration temperature span of the magnetic refrigeration device under load, the number of refrigeration modules N established based on the above embodiment 1 is S =4, ΔT MCE =4K, the thickness of the heat recovery layer Cu sheet is 1.4mm, the working frequency is 1Hz, the temperature of the hot end is fixed, and a load is added to the cold end to study the cooling temperature span of the device under load. Figure 8 It can be seen that as the load increases, the equilibrium temperature span decreases linearly, and the cooling power of the device exceeds 0.06W at an operating frequency of 1Hz.

Claims

1. A high-efficiency heat-recovery all-solid-state magnetic refrigeration device operating in a single magnetic field, comprising at least one refrigeration unit, wherein the refrigeration unit comprises a refrigeration layer and a heat-recovery layer arranged in parallel, wherein: - the refrigeration layer comprises a plurality of magnetic refrigeration medium sheets embedded in the first insulation material at intervals; - the heat recovery layer comprises a plurality of heat recovery medium sheets embedded in the second heat insulation material, Among them, the number of magnetic refrigeration working medium sheets = the number of regenerative working medium sheets + 1, the setting of the refrigeration unit enables the refrigeration layer and the regenerative layer to perform reciprocating translational motion respectively during operation, and there is heat conduction between the magnetic refrigeration working medium sheets and the regenerative working medium sheets.

2. The magnetic refrigeration device according to claim 1, wherein: The refrigeration unit is configured so that each of the magnetic refrigeration working fluid sheets only exchanges heat with two adjacent heat recovery working fluid sheets at relative positions during the reciprocating translational motion; and each of the heat recovery working fluid sheets only exchanges heat with two adjacent magnetic refrigeration working fluid sheets at relative positions during the reciprocating translational motion.

3. The magnetic refrigeration device according to claim 1 or 2, wherein: The size of the refrigeration layer is equal to that of the heat recovery layer; the size of the magnetic refrigeration medium sheet is equal to that of the heat recovery medium sheet.

4. The magnetic refrigeration device according to any one of claims 1 to 3, wherein: The material of the magnetic refrigeration medium sheet is one or more of Gd, FeRh, LaFeSi, GdSiGe, MnAs, MnPSiGe and NiMnX, preferably Gd, Gd5(Si,Ge)4, La(Fe,Si) 13 , MnCoGe and NiMnSn; The material of the heat recovery working fluid sheet is one or more of copper, silver, gold, aluminum, platinum, iron, graphene, carbon nanotubes and diamond aluminum alloy, preferably copper or graphene; preferably, the ratio of the thickness of the heat recovery working fluid sheet to the thickness of the refrigeration working fluid sheet is 0.5 to 3:

1. The first thermal insulation material and the second thermal insulation material are the same or different, and are each independently selected from one or more of glass fiber, asbestos, rock wool, silicate, aerogel felt and vacuum panel.

5. The magnetic refrigeration device according to any one of claims 1 to 4, wherein: The distance between the cooling layer and the heat recovery layer is 0-10 nm; preferably, graphite powder is arranged between the cooling layer and the heat recovery layer.

6. The magnetic refrigeration device according to any one of claims 1 to 5, wherein: The magnetic refrigeration device comprises a refrigeration array composed of a plurality of refrigeration units, wherein the plurality of refrigeration units are stacked up and down to form a structure in which a refrigeration layer and a heat recovery layer are overlapped and arranged; Preferably, the refrigeration array includes 2 to 100 refrigeration units, more preferably 2 to 25; preferably, the refrigeration layer includes 2 to 100 magnetic refrigeration working fluid sheets, preferably 4 to 25; the number of heat recovery working fluid sheets in the heat recovery layer is 1 less than the number of magnetic refrigeration working fluid sheets in the refrigeration layer.

7. Application of the high-efficiency heat-recovery all-solid-state magnetic refrigeration device operating in a single magnetic field according to any one of claims 1 to 6 in refrigerators, air conditioners, liquefied gases and microelectronic device refrigeration.

8. The use according to claim 7, wherein: The application includes placing the magnetic refrigeration device in a continuous magnetic field generated by a single magnet, so that in one terminal state of the reciprocating translational motion of the refrigeration layer, the multiple magnetic refrigeration working medium sheets are all within the magnetic field, and in another terminal state, the multiple magnetic refrigeration working medium sheets are all outside the magnetic field.

9. The use according to claim 7, wherein: The intensity of the magnetic field is 0.1 to 60 T, preferably 0.5 to 3 T; Preferably, the reciprocating translational motion frequencies of the refrigeration layer and the heat recovery layer are the same, preferably 0.01 to 1000 Hz, more preferably 0.1 to 20 Hz.

10. The use according to claim 8 or 9, wherein: The application includes matching the magnetic refrigeration device with a cold end that needs to be refrigerated and a hot end that performs heat dissipation, wherein the cold end and the hot end are respectively located at two movement terminals of the reciprocating translational motion of the magnetic refrigeration device, and heat is exchanged with the two outermost ones of the plurality of magnetic refrigeration working medium sheets at the two movement terminals respectively. Wherein, when the cold end is located on the left and the hot end is located on the right, the application includes: starting from the hot end on the right, placing 40% to 70% of the area spanned by the reciprocating motion of the magnetic refrigeration device in the magnetic field, and operating according to the following timing: (1) The refrigeration layer and the heat recovery layer are stationary at the cold end movement terminal, wherein each refrigeration medium sheet is in thermal contact with the heat recovery medium sheet on the left side and the cold end, respectively, and absorbs heat from the cold end and the heat recovery medium sheet on the left side; (2) The cooling layer and the regenerative layer move toward the hot end and enter the magnetic field at the same time. The cooling layer moves faster than the regenerative layer. The cooling medium sheet enters the magnetic field after leaving the cold end and the regenerative medium sheet on the left and before contacting the regenerative medium sheet on the right and the hot end to complete the heating process. (3) After entering the magnetic field, the cooling layer and the heat recovery layer are stationary at the hot end movement terminal, wherein each cooling medium sheet is in thermal contact with the right heat recovery sheet and the hot end, respectively, and releases heat to the hot end and the right heat recovery sheet; (4) The cooling layer and the regenerative layer move toward the cold end and leave the magnetic field at the same time. The cooling layer moves faster than the regenerative layer. The refrigerant sheet completes the cooling process out of the magnetic field after leaving the hot end and the right regenerative sheet and before contacting the left regenerative sheet and the cold end. (5) According to the order of (1)-(4), the above operations are switched back and forth, so as to transport heat from the cold end to the hot end to achieve refrigeration; Alternatively, the application includes operating in the following sequence: the cooling layer and the heat recovery layer first enter the magnetic field and stop at the moving terminal described in (3). After cooling to room temperature and completing initialization, the above operations are switched back and forth in the order of (3)-(4)-(1)-(2) to transport heat from the cold end to the hot end to achieve cooling.

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