A reciprocating all-solid-state magnetic refrigeration device and its application

Abstract

The present invention provides a reciprocating all-solid-state magnetic refrigeration device, which includes at least one refrigeration unit. The refrigeration unit includes a refrigeration layer and a heat conduction layer arranged in parallel. The refrigeration layer includes a plurality of magnetic refrigeration working medium sheets embedded in a first heat insulating material at intervals, and the heat conduction layer includes a plurality of heat conduction working medium sheets embedded in a second heat insulating material at intervals. There is heat conduction between the magnetic refrigeration working medium sheets and the heat conduction working medium sheets, and the refrigeration layer and the heat conduction layer can perform reverse reciprocating translational motion. The regenerative process of the magnetic refrigeration device is realized by direct heat exchange between two adjacent refrigeration layers and heat conduction layers. Since there is no external regenerative module, irreversible regenerative losses are eliminated, thereby improving the cooling power density.

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 without the assistance of a regenerator and its application. Background Art

[0002] Magnetic refrigeration technology is a technology that realizes refrigeration through the entropy change and temperature change caused by the phase change of magnetic refrigeration materials during the processes of applying and removing a magnetic field. In the process of traditional gas compression refrigeration, a large amount of Freon refrigerant that damages the ozone layer and causes the greenhouse effect is required; while the refrigerators using magnetic refrigeration technology do not generate and utilize environmentally harmful chemical substances, 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, has no noise pollution, and can be miniaturized. 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 forms: external regenerator, internal regenerator, and active regenerator. The magnetic material in the active magnetic regenerative cycle (AMR) is both a magnetic working medium and a regenerative material. By reducing the heat loss during the regeneration process, it has become the magnetic refrigeration cycle mode with the highest energy utilization efficiency recognized at present, and has been applied to many refrigerator cycles successively. The initial traditional AMR cycle was completed through fluid heat exchange. However, in order to meet the characteristics of non-conductivity or non-magnetism, the heat transfer fluid often sacrifices its high thermal conductivity, which limits the heat exchange speed and restricts the operating frequency of the device to about 1 Hz. If the operating frequency is blindly increased, it will cause insufficient heat conduction, thereby reducing the refrigeration capacity 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 of the device, as well as the relatively rough mechanical control device of the fluid, have an inestimable impact on the refrigeration efficiency of the device. In addition, the corrosion problem of the heat transfer fluid to the magnet and the refrigeration working medium also brings difficulties to the design of the magnetic refrigeration device, thereby increasing the manufacturing cost of the refrigeration device.

[0005] To solve a series of problems brought by traditional AMR based on fluid heat exchange, a new type of all-solid-state magnetic refrigeration model with regenerative heat using a solid heat transfer medium with high thermal conductivity has received great attention. Currently, the reported all-solid-state refrigeration models are mainly of two types. One is the all-solid-state magnetic refrigeration model based on thermal diodes (electrically controlled thermal diodes and magnetically controlled thermal diodes), and the other is the all-solid-state refrigeration model based on materials with high thermal conductivity. Among them, for the all-solid-state magnetic refrigeration model using a Peltier element (electrically controlled thermal diode) as the solid heat conduction medium based on a thermal diode, in order to complete heat conduction faster, a relatively large working current needs to be input into the Peltier element, which increases the electric power loss (i.e., external work) of the entire system, resulting in a reduction in the COP (coefficient of performance) of the entire refrigeration system and a decrease in refrigeration efficiency. If the working current is reduced, it can indeed reduce the electric power loss, but at the same time, it also reduces the heat conduction speed, reduces the refrigeration capacity, and reduces the working frequency, which violates the original intention of introducing the thermal diode. Therefore, introducing a Peltier element can increase the working frequency and refrigeration power of the all-solid-state magnetic refrigeration system, but at the same time, it inevitably introduces electric power loss, which has a negative impact on the refrigeration efficiency. On the other hand, although the all-solid-state refrigeration model based on magnetically controlled thermal diodes can achieve significant improvements in specific power density, COP, and refrigeration temperature span, it is difficult to obtain magnetically controlled thermal diode materials that meet the actual application conditions. Therefore, the restriction of the heat transfer medium greatly hinders the research, application, and development of the all-solid-state magnetic refrigeration model. Summary of the Invention

[0006] Therefore, the objective of the present invention is to develop an all-solid-state magnetic refrigeration device that breaks through the restriction of traditional heat transfer media, adopts a new type of regenerative heat and refrigeration method, and realizes low regenerative heat loss and high energy utilization efficiency at high-frequency operation.

[0007] The inventors of the present invention have 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 ideal heat conduction media. On the other hand, insulating materials such as glass fiber, asbestos, rock wool, silicate, aerogel felt, and vacuum panel can effectively prevent irrelevant heat exchange between the magnetic refrigeration working medium, heat conduction medium, and the outside world, thereby reducing heat loss. Therefore, the inventors combined materials with high thermal conductivity as the heat conduction medium with magnetic refrigeration materials and insulating materials, and achieved all-solid-state magnetic refrigeration with high refrigeration efficiency through reasonable device design. In addition, since the magnetic refrigeration working medium, heat conduction medium, and insulating material are all solid, it is convenient to design and process them into different shapes and sizes, and it is also convenient for mechanical devices to perform relatively precise control. Therefore, the all-solid-state refrigeration device based on high thermal conductivity materials can achieve device refrigeration at different scales (sub-micron - meter).

[0008] The object of the present invention is achieved by the following technical solutions.

[0009] The present invention provides a reciprocating all-solid-state magnetic refrigeration device, which includes at least one refrigeration unit. The refrigeration unit includes a refrigeration layer and a heat conduction layer arranged in parallel. The refrigeration layer includes a plurality of magnetic refrigeration working medium sheets (also referred to as "refrigeration sheets" in the present invention) embedded at intervals in a first heat insulating material, and the heat conduction layer includes a plurality of heat conduction working medium sheets (also referred to as "heat conduction sheets" in the present invention) embedded at intervals in a second heat insulating material. Among them, the arrangement of the refrigeration unit enables the refrigeration layer and the heat conduction layer to perform reverse reciprocating translational motion, and there is heat conduction between the magnetic refrigeration working medium sheet and the heat conduction working medium sheet.

[0010] Wherein the "reverse" means that the moving directions of the refrigeration layer and the heat conduction layer are opposite.

[0011] In a preferred embodiment of the present invention, the arrangement of the refrigeration unit enables at least one of the plurality of magnetic refrigeration working medium sheets to conduct heat with at least two heat conduction working medium sheets among the plurality of heat conduction working medium sheets in sequence during the reciprocating translational motion.

[0012] In a more preferred embodiment of the present invention, the arrangement of the refrigeration unit enables each magnetic refrigeration working medium sheet among the plurality of magnetic refrigeration working medium sheets to conduct heat with two adjacent heat conduction working medium sheets among the plurality of heat conduction working medium sheets in sequence during the reciprocating translational motion.

[0013] According to the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, the heat conduction layer includes a cold-end heat conduction working medium sheet and a hot-end heat conduction working medium sheet respectively close to two moving terminals (both ends along the moving direction) of the heat conduction layer.

[0014] According to the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, during operation, a part of the magnetic refrigeration device is placed in a magnetic field. Preferably, 40% - 70% of the projected area of the magnetic refrigeration device is placed in the magnetic field, and more preferably, 45% - 55% of the projected area of the magnetic refrigeration device is placed in the magnetic field; in a most preferred embodiment, half (i.e., 50%) of the projected area of the magnetic refrigeration device is placed in the magnetic field.

[0015] Among them, the magnetic field is a discontinuous segmented magnetic field, such that in one terminal state of the reciprocating translational motion of the refrigeration layer, the multiple magnetocaloric working substance sheets are all within the magnetic field, while in the other terminal state, the multiple magnetocaloric working substance sheets are all outside the magnetic field. Through the reciprocating translational motion, each of the multiple magnetocaloric working substance sheets in the refrigeration layer reciprocates between the magnetic field region and the non-magnetic field region, and each magnetocaloric working substance sheet reciprocally conducts heat with two adjacent heat-conducting working substance sheets among the multiple heat-conducting working substance sheets of the heat-conducting layer, thereby forming a cold-end heat-conducting working substance sheet and a hot-end heat-conducting working substance sheet at both ends of the heat-conducting layer.

[0016] Among them, the magnetic field is preferably a uniform magnetic field, and the intensity of the magnetic field can be 0.1 - 60 T, preferably 0.5 T - 2 T. The frequency of the reciprocating motion of the refrigeration layer can be 0.01 - 1000 Hz, preferably 1 - 20 Hz, and the frequency of the reciprocating motion of the heat-conducting layer can be 0.01 - 1000 Hz, preferably 1 - 20 Hz. The reciprocating motion frequencies of the refrigeration layer and the heat-conducting layer are the same.

[0017] For the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, among them, the magnetocaloric working substance sheet can be composed of any magnetocaloric material, for example, it can be selected from one or more of Gd, FeRh, LaFeSi, GdSiGe, MnAs, MnPSiGe, and NiMnX, preferably one or more of Gd, Gd5(Si,Ge)4, La(Fe,Si) 13 、MnCoGe, and NiMnSn.

[0018] For the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, among them, the heat-conducting working substance sheet can be composed of any heat-conducting material, such as copper, silver, gold, aluminum, platinum, iron, graphene, diamond aluminum alloy, and carbon nanotubes, etc., preferably inexpensive and easily available materials such as copper and graphene.

[0019] For the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, among them, the first thermal insulation material and the second thermal insulation material can be the same or different, and can be independently selected from one or more of fiberglass, asbestos, rock wool, silicate, aerogel felt, and vacuum panel.

[0020] For the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, among them, any known method can be used to embed the magnetocaloric working substance sheet in the first thermal insulation material of the refrigeration layer or to embed the heat-conducting working substance sheet in the second thermal insulation material of the heat-conducting layer, such as bonding with epoxy resin glue. Any known method can be used to assemble one or more refrigeration layers and one or more heat-conducting layers together, as long as the refrigeration layer and the heat-conducting layer can independently translate in opposite directions, for example, each heat-conducting layer or each refrigeration layer can be controlled by a linear stepper motor separately.

[0021] In a preferred embodiment of the present invention, in order to achieve optimal heat conduction between the refrigeration layer and the heat conduction layer and reduce the additional loss caused by frictional work, graphite powder or other heat-conducting material powder is provided between the refrigeration layer and the heat conduction layer. Preferably, the distance between the refrigeration layer and the heat conduction layer can be 0 to 10 nm.

[0022] In some preferred embodiments of the present invention, the sizes of the magnetic refrigeration working medium sheets, the heat conduction working medium sheets, the first heat insulation material located between two adjacent magnetic refrigeration working medium sheets, and the second heat insulation material located between two adjacent heat conduction working medium sheets are of the same order of magnitude.

[0023] According to the reciprocating all-solid-state magnetic refrigeration device provided by the present invention, the number of the refrigeration units can be selected from 1 to 100 according to actual refrigeration requirements, preferably 2 to 25.

[0024] The present invention does not particularly limit the shapes of the refrigeration layer, the heat conduction layer, the magnetic refrigeration working medium sheets, and the heat conduction working medium sheets. In a preferred embodiment, for the convenience of manufacturing and controlling the heat transfer effect, the refrigeration layer, the heat conduction layer, the magnetic refrigeration working medium sheets, and the heat conduction working medium sheets are all rectangular. Preferably, the multiple magnetic refrigeration working medium sheets are equally spaced and embedded in the first heat insulation material of the refrigeration layer, and the multiple heat conduction working medium sheets are equally spaced and embedded in the second heat insulation material of the heat conduction layer. Among them, the refrigeration layer preferably includes 2 to 100 magnetic refrigeration working medium sheets, more preferably 4 to 25; the heat conduction layer preferably includes 2 to 100 heat conduction working medium sheets, more preferably 4 to 25. In a preferred embodiment of the present invention, the number of magnetic refrigeration working medium sheets included in the refrigeration layer is one less than the number of heat conduction working medium sheets included in the heat conduction layer.

[0025] On the other hand, the present invention also provides an application of the above-mentioned reciprocating all-solid-state magnetic refrigeration device in refrigerators, air conditioners, liquefied gases, and microelectronic device refrigeration.

[0026] The application includes placing the reciprocating all-solid-state magnetic refrigeration device in a discontinuous segmented magnetic field, such 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. Preferably, the intensity of the magnetic field is 0.1 to 60 T, more preferably 0.5 T to 2 T. Among them, the reciprocating translational motion frequencies of the refrigeration layer and the heat conduction layer are the same, preferably 0.01 to 1000 Hz, more preferably 1 to 20 Hz.

[0027] For simplicity, taking the reciprocating all-solid-state magnetic refrigeration device with one refrigeration layer and one heat conduction layer as an example, in combination with Figure 1 andFigure 2 Describe the preferred working mode of the device of the present invention.

[0028] 1) Before the all-solid-state magnetic refrigeration device operates, the refrigeration layer and the heat conduction layer stay at the movement terminals in opposite directions respectively. At each movement terminal, each refrigeration chip of the refrigeration layer is in direct or indirect contact (ensuring the best heat conduction) with two corresponding heat conduction chips in the heat conduction layer, and between multiple refrigeration chips and between multiple heat conduction chips are separated by heat insulation materials to maintain heat insulation. During operation, the refrigeration layer and the heat conduction layer will perform reverse reciprocating translational motion.

[0029] 2) Apply a magnetic field through a common permanent magnet or an electromagnet. The magnetic field region is constantly stationary and is set in sections. Preferably, the distance between every two sections is twice the length of the refrigeration chip. In one terminal state, multiple refrigeration chips are in the magnetic field, while in the other terminal state, the refrigeration chips are outside the magnetic field.

[0030] 3) Since multiple refrigeration chips of the refrigeration layer and multiple heat conduction chips of the heat conduction layer are separated by heat insulation materials, there is no heat transfer between the multiple refrigeration chips and the multiple heat conduction chips. Heat transfer only exists between the refrigeration layer and the heat conduction layer.

[0031] 4) The cold end and the hot end are respectively set at the two movement terminals of the heat conduction layer. Figure 1 As shown, the cold end is set on the left and the hot end is set on the right. Since the refrigeration layer and the heat conduction layer move in reverse, when the refrigeration layer reaches the left end, the heat conduction layer reaches the right end, and vice versa. This can ensure that each refrigeration chip will contact two heat conduction chips in one cycle. When the refrigeration chip reaches the left end, the refrigeration chip exits the magnetic field and the temperature decreases. At this time, the heat conduction layer moves to the right end, and the left heat conduction chip contacts the refrigeration chip, and heat is conducted from the left heat conduction chip to the refrigeration chip. At the next moment, the refrigeration layer moves to the right end and enters the magnetic field, the temperature rises, the heat conduction layer moves to the left end, and at this time, the right heat conduction chip contacts the refrigeration chip, and heat is conducted from the refrigeration chip to the right heat conduction chip. At the same time, when the heat conduction layer moves to the left end, the leftmost heat conduction chip contacts the cold end, and heat is conducted from the cold end to the leftmost heat conduction chip; similarly, when the heat conduction layer moves to the right end, the rightmost heat conduction chip contacts the hot end, and heat is conducted from the rightmost heat conduction chip to the hot end. Thus, heat is transported from the cold end to the hot end to achieve refrigeration.

[0032] 5) The hot end and the cold end are in contact with the outside through a heat conduction medium connected under the high heat conduction material to exchange heat, absorb heat from the cold source (i.e., refrigerate the cold end) and release the heat of the hot end to the surrounding environment.

[0033] 6) During the reverse reciprocating motion of the heat conductive layer, the heat at the cold end is transferred to the hot end through the heat conductive sheet. Under no-load conditions, since multiple cooling sheets in a single layer and multiple heat conductive sheets are insulated from each other, the temperature span can be widened by separate cascade cooling sheets and heat conductive sheets.

[0034] 7) By utilizing the high thermal conductivity of the heat-conducting layer, rapid heat recovery is achieved and the heat exchange efficiency is improved, thereby realizing efficient all-solid-state magnetic refrigeration under high-frequency working conditions.

[0035] Specifically, the working principle of the all-solid-state magnetic refrigeration device of the present invention is as follows:

[0036] During the operation of the device, the cooling layer and the heat conducting layer move back and forth in opposite directions, with two terminals in the process of movement. At each terminal, each cooling layer has a heat conducting layer in contact with it accordingly. The cold end and the hot end are respectively placed at the two moving terminals of the heat conducting layer, and they only contact the heat conducting layer when they move near the terminals. Because it is a reverse movement, when the cooling layer moves to the left end, the heat conducting layer moves to the right end; when the cooling layer moves to the right end, the heat conducting layer moves to the left end: this ensures that each cooling plate contacts two heat conducting plates during the entire movement, that is, it contacts two different heat conducting plates at the two terminals.

[0037] When the cooling layer moves to the right, it enters the magnetic field and the temperature rises. At this time, the heat conducting plate moves to the left, and the cooling plate contacts the heat conducting plate on the right. Heat is transferred from the cooling plate to the heat conducting plate on the right. At the same time, the heat conducting plate at the far left contacts the cold end, and heat is transferred from the cold end to the heat conducting plate at the far left.

[0038] When the cooling layer moves to the left end, the cooling layer goes out of the magnetic field area and the temperature drops. At this time, the heat conducting plate moves to the right end, the cooling plate contacts the heat conducting plate on the left, and the heat is transferred from the heat conducting plate on the left to the cooling plate. At the same time, the heat conducting plate at the far right contacts the hot end, and the heat is transferred from the heat conducting plate at the far right to the hot end.

[0039] Although the heat conducting sheet itself does not produce any thermal effect, the heat is continuously transferred from the left heat conducting sheet to the right heat conducting sheet through the reverse movement of the heat conducting layer and the cooling layer, so that the heat is continuously transferred from the cold end to the hot end in the entire device to achieve cooling. Since there is no cascade design for heat exchange between multiple cooling sheets on the same layer and between multiple heat conducting sheets on the same layer, although the adiabatic temperature change of each cooling sheet is very limited, a very considerable temperature span can be achieved.

[0040] Through the introduction of the cascade module design, the temperature span between the cold source and the heat source is broadened, that is, the refrigeration temperature span is broadened. Although the adiabatic temperature change of magnetocaloric materials can reach 20K, usually a relatively high magnetic field is required, which brings great difficulties to the design and cost of magnetocaloric devices. The device designed in the present invention can enable the magnetocaloric working medium to provide a larger refrigeration temperature span under a limited adiabatic temperature change, so it has important significance. At the same time, the introduction of the heat conduction layer avoids the use of a regenerator, simplifies the device design, and due to the high thermal conductivity of the heat conduction layer, the heat regeneration rate is accelerated, the heat regeneration loss is reduced, and the requirements for high-frequency operation are met.

[0041] Compared with the prior art, the advantages of the present invention are as follows: For the first time, a fully solid-state reciprocating magnetocaloric device without an external regenerator and simply composed of a magnetocaloric working medium and a high-thermal-conductivity material is proposed. Its core components are composed of two types of functional layers: a refrigeration layer composed of a magnetocaloric working medium and an adiabatic material, and a heat conduction layer composed of a high-thermal-conductivity material and an adiabatic material. The refrigeration layer and the heat conduction layer are alternately arranged from top to bottom to form a fully solid-state refrigeration model, and the refrigeration layer and the heat conduction layer move in reverse parallel to achieve heat regeneration and refrigeration. Its heat regeneration process is realized by direct heat exchange between two adjacent refrigeration layers and heat conduction layers. Since there is no external heat regeneration module, the irreversible heat regeneration loss is eliminated, thereby providing a high cooling power density for the device. At the same time, taking advantage of the high thermal conductivity of the high-thermal-conductivity material, heat is quickly exchanged between the refrigeration layer and the heat conduction layer, enabling the refrigeration device to operate at high frequencies while having excellent cooling power density. At the same time, the unique heat regeneration process of the device makes the refrigeration temperature span much larger than the adiabatic temperature change of single-element magnetocaloric materials (when the number of single-layer refrigeration chips Ns = 4, the heat regeneration coefficient r = 4), providing a feasible means for developing high-performance magnetocaloric devices using existing magnetocaloric materials. By adjusting the lengths of the rectangular refrigeration layer and the heat conduction layer and the number of alternating layers, devices with different scales can be realized for refrigeration, that is, the fully solid-state magnetocaloric device designed in the present invention can be applied to refrigeration on a large scale such as refrigerators and air conditioners, and can also be applied to the refrigeration of micro-nano scale devices to solve the heat dissipation problem when micro-nano devices such as chips work. The fully solid-state magnetocaloric device provided by the present invention is a brand-new fully solid-state refrigeration device using a high-thermal-conductivity material as the heat conduction medium. Due to its wide temperature span and high refrigeration efficiency, this model device has potential application value in refrigeration such as refrigerators, air conditioners, liquefied gases, and microelectronic devices. Description of the Drawings

[0042] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings, where:

[0043] Figure 1 It is a schematic diagram of the working mode of the reciprocating fully solid-state magnetocaloric device of the present invention;

[0044] Figure 2Schematic diagram of two moving terminals of the reciprocating all-solid-state magnetic refrigeration device of the present invention;

[0045] Figure 3 Schematic diagram of the mesh division model of the all-solid-state magnetic refrigeration device using rectangular refrigeration sheets and heat conduction sheets in the finite element simulation in the embodiment;

[0046] Figure 4 Schematic diagram of the temperature when each refrigeration module and the cold and hot end modules reach equilibrium in the embodiment;

[0047] Figure 5 Data graph of the influence of Cu thickness on the equilibrium temperature span and the relaxation time to reach equilibrium;

[0048] Figure 6 Data graph of the influence of adiabatic temperature change on the equilibrium temperature span;

[0049] Figure 7 Data graph of the influence of the number of refrigeration sheets on the equilibrium temperature span;

[0050] Figure 8 Data graph of the influence of frequency on the equilibrium temperature span and the relaxation time to reach equilibrium;

[0051] Figure 9 Data graph of the refrigeration capacity of the reciprocating all-solid-state magnetic refrigeration device in the embodiment. Detailed implementation manners

[0052] The present invention will be further described in detail below in conjunction with the specific implementation manners. The provided embodiments are only for clarifying the present invention and not for limiting the scope of the present invention.

[0053] Figure 1 Schematic diagram of the working mode of the reciprocating all-solid-state magnetic refrigeration device of the present invention adopted in the embodiment. Figure 2 Schematic diagram of two moving terminals of the reciprocating all-solid-state magnetic refrigeration device of the present invention adopted in the embodiment.

[0054] The all-solid-state magnetic refrigeration device includes one or more rectangular refrigeration layers and one or more rectangular heat conduction layers that are alternately stacked. The rectangular refrigeration layer includes a plurality of rectangular refrigeration sheets and the adiabatic material connecting them together. The rectangular heat conduction layer includes a plurality of rectangular heat conduction sheets and the adiabatic heat material connecting them together. The rectangular refrigeration layer and the rectangular heat conduction layer can translate in opposite directions. Half of the projected area of the all-solid-state magnetic refrigeration device is placed in the magnetic field. If it is other irregular planar shapes, the rectangle can be changed into the corresponding shape.

[0055] In the embodiment, finite element simulation is used to calculate the refrigeration temperature span and refrigeration efficiency during the operation of the all-solid-state magnetic refrigeration device designed in the present invention. The specific parameter descriptions are as follows:

[0056] 1) Both the refrigeration layer and the heat conduction layer are rectangular. The total length of the device is 0.5 mm to 10,000 mm, preferably 5 to 200 mm. The refrigeration chips and heat conduction chips in it have the same length and width, which is 0.1 mm to 100 mm, preferably 1 mm to 10 mm. The thickness of each layer can be selected according to actual needs and can be selected as 0.01 mm to 50 mm, preferably 0.1 to 5 mm.

[0057] 2) The refrigeration layer and the heat conduction layer are alternately arranged from top to bottom. Each refrigeration unit is composed of two layers (one refrigeration layer and one heat conduction layer). The number of refrigeration units stacked up and down can be selected as 1 to 100 according to actual refrigeration needs, that is, 2 to 200 layers. The preferred number of refrigeration units stacked up and down is 2 to 25, that is, 4 to 50 layers. In order to achieve the alternate stacking setting, the number of rectangular refrigeration layers is within the range of ±1 of the rectangular heat conduction layer. Preferably, the number of rectangular refrigeration layers is equal to the number of rectangular heat conduction layers.

[0058] 3) In each layer of the refrigeration layer and the heat conduction layer, the number of refrigeration modules is one less than that of the regenerative modules, preferably 4 to 20, and the number of blocks can reach 100 according to actual needs.

[0059] 4) The adiabatic module is replaced by an adiabatic boundary in the simulation.

[0060] 5) The adiabatic temperature change generated when the refrigeration working medium enters and exits the magnetic field is 0.1 to 20 K.

[0061] 6) The software used for the finite element simulation is the solid heat transfer module in COMSOL Multiphysics 5.3.A.

[0062] 7) According to different actual refrigeration needs, the initial temperatures of the refrigeration layer and the heat conduction layer are set to 0.1 K to 1000 K.

[0063] Hereinafter, a representative case is given to illustrate the simulation method of the "all-solid-state magnetic refrigeration device" of the present invention:

[0064] 1) In the model, a refrigeration unit is simply composed of one layer of refrigeration working medium and one layer of high thermal conductivity material. It is set that there are 4 rectangular refrigeration chip modules in each layer and 5 rectangular heat conduction chip modules in each layer. Its geometric model is as Figure 1 , and two moving terminals (hot and cold end heat sources) and the magnetic field are as Figure 2As shown. The initial temperatures of all the refrigeration layers and heat conduction layers are set to 295K. The cold source and heat source are located at the two moving terminals of the heat conduction layer. Among them, when the refrigeration module moves to the right end, that is, in state 2, it enters the magnetic field and the temperature will increase by 3K; similarly, when the refrigeration module moves to the left end, that is, in state 1, it moves out of the magnetic field and the temperature will decrease by 3K. With the reverse movement of the refrigeration layer and the heat conduction layer, each refrigeration chip contacts the heat conduction chip on the right when it moves to the right end (state 2) and transfers heat to the heat conduction chip on the right; each refrigeration chip contacts the heat conduction chip on the left when it moves to the left end (state 1), and heat is transferred from the heat conduction chip on the left to the right, and heat continuously transfers from the cold end on the left to the hot end on the right. As the cycle progresses, the temperature finally reaches a stable state. The temperature difference between the hot end and the cold end at the steady state is the maximum temperature span of this all-solid-state magnetic refrigeration model device under no-load conditions.

[0065] 2) Among them, heat exchange can only occur when the refrigeration chip contacts the heat conduction chip and when the heat conduction chip contacts the cold and hot ends, and the rest of the boundaries are adiabatic boundaries. In order to describe the translational reciprocating motion of the upper magnetic refrigeration medium and the lower heat conduction medium, a dynamic mesh boundary condition is defined in the model, and it is set that the upper magnetic refrigeration medium and the lower heat conduction medium perform reciprocating motion with a period of 0.1s (frequency of 10Hz), and a total of 90 cycles are carried out, and the total calculation time domain is 9s.

[0066] 3) This model uses tetrahedral elements for adaptive free mesh generation, and the mesh model is as Figure 3 shown.

[0067] 4) This model uses transient solution. The calculation time domain has a cycle period of 0.1s, the time step size does not exceed 0.0003s, the total time is 9s, and a direct strong coupling solver is used for solution, combined with the nonlinear Newton iteration method, and the convergence factor is 0.01.

[0068] 5) Based on the above-established finite element simulation model, through the setting calculation of the initial parameters, as the cycle progresses, the temperature difference distribution of the refrigeration working medium gradually tends to be stable. In order to more clearly see the change of the temperature of this all-solid-state magnetic refrigeration device with time, the change curves of the temperatures of the hot and cold ends and each refrigeration chip after stabilization with time are shown in Figure 4 Among them, the top and bottom horizontal lines are the hot end and the cold end respectively, and the four fluctuating curves from top to bottom in the middle correspond to the 4 refrigeration chips from right to left. It can be seen from this that the hot end temperature stabilizes at about 301.5K, the cold end temperature stabilizes at about 289.5K, and the formed 12K temperature span corresponds to 4 refrigeration chips, and the no-load maximum temperature span of the device when the adiabatic temperature change of the refrigeration chip is 3K.

[0069] 6) Based on the established finite element simulation model above, the maximum temperature span of the device and the relaxation time to reach equilibrium were calculated under different thicknesses of the high thermal conductivity material Cu, which were 0.04 - 0.2 mm, as Figure 5 shown. It can be seen that the change in the thickness of Cu basically does not affect the maximum temperature span at equilibrium, but it will affect the relaxation time to reach equilibrium. When the thickness of copper is very thin, the heat-carrying capacity of Cu is very low, which leads to a longer time required for the formation of the equilibrium temperature span; similarly, when copper is relatively thick, due to the higher movement frequency, the heat regeneration process is incomplete, resulting in a longer time required for the formation of the equilibrium temperature span. Therefore, there is an optimal thickness, which is 0.08 mm here, to make the relaxation time for the formation of the equilibrium temperature span the shortest.

[0070] 7) Based on the established finite element simulation model above, the influence of the adiabatic temperature changes ΔTMCE generated under different magnetic fields, which were 6K, 5K, 4K, 3K, and 2K respectively, on the maximum refrigeration temperature span was calculated as Figure 6 shown, and the influence of different numbers of refrigeration chips, which were NS = 2, 3, 4, 5, and 6 respectively, on the maximum refrigeration temperature span was also calculated, as Figure 7 shown. From the above two figures, a very simple and intuitive rule can be summarized that at equilibrium, that is, the maximum refrigeration temperature span is equal to the number of refrigeration chips multiplied by the adiabatic temperature change.

[0071] 8) Based on the established finite element simulation model above, the equilibrium temperature span and relaxation time of the device were calculated at different operating frequencies, as Figure 8 shown. It can be seen that the frequency below 50 Hz has no influence on the equilibrium temperature span of the device, but the relaxation time decreases with the increase of the frequency. When the frequency is higher than 50 Hz, reaching 1000 Hz or even 10000 Hz, it may have a certain influence on the equilibrium temperature span of the device due to the too short heat exchange time, and this was not calculated completely here.

[0072] 9) In order to study the refrigeration efficiency of the all-solid-state magnetic refrigeration model device designed in this paper, based on the finite element simulation model when the number of refrigeration modules N S = 4, by changing the boundary conditions, that is, giving a heating power to the cold end and making the hot end an infinite heat source fixed at 295K, the data as Figure 9 shown were calculated. It can be seen that there is a corresponding equilibrium temperature span for a refrigeration power, and the maximum power of this device can reach 4 mW. In order to increase the power, on the one hand, the operating frequency can be increased, on the other hand, the area of the refrigeration block can be increased, or multiple layers of refrigeration units can be stacked.

[0073] The composition of the refrigeration working medium and heat conduction medium, the operating frequency, and the size of the all-solid-state refrigeration device model obtained in each embodiment are specifically described below.

[0074] Example 1

[0075] Thermoelectric cooler: Gd, heat sink: Cu

[0076] Number of rectangular thermoelectric coolers in each cooling layer: 4; Number of rectangular heat sinks in each heat transfer layer: 5. The length and width of the thermoelectric cooler and the heat sink are the same: 1 mm; The thickness is Gd(0.2 mm) / Cu(0.1 mm)

[0077] Total length of a thermoelectric cooling unit model: 15 mm

[0078] Operating frequency: 10 Hz

[0079] Adiabatic temperature change generated during the Gd sheet entering the magnetic field: 3 K

[0080] Example 2

[0081] Thermoelectric cooler: Gd, heat sink: Cu

[0082] Number of rectangular thermoelectric coolers in each cooling layer: 4; Number of rectangular heat sinks in each heat transfer layer: 5. The length and width of the thermoelectric cooler and the heat sink are the same: 1 mm; The thickness is Gd(0.2 mm) / Cu(0.1 mm)

[0083] Operating frequency: 1 Hz

[0084] Adiabatic temperature change generated during entering the magnetic field: 5 K

[0085] Total length of a thermoelectric cooling unit model: 15 mm

[0086] Example 3

[0087] Thermoelectric cooler: Gd, heat sink: Cu

[0088] Number of rectangular thermoelectric coolers in each cooling layer: 4; Number of rectangular heat sinks in each heat transfer layer: 5. The length and width of the thermoelectric cooler and the heat sink are the same: 5 mm; The thickness is Gd(0.2 mm) / Cu(0.1 mm)

[0089] Operating frequency: 100 Hz

[0090] Adiabatic temperature change during entering the magnetic field: 6 K

[0091] Total length of a thermoelectric cooling unit model: 75 mm

[0092] Example 4

[0093] Thermoelectric cooler: Gd5(Si,Ge)4, heat sink: Ag

[0094] Number of rectangular refrigeration sheets in each refrigeration layer: 10; Number of rectangular heat conduction sheets in each heat transfer layer: 11. The length and width of the refrigeration working medium sheet and the heat conduction working medium sheet are the same: 2 mm; Thickness: Gd5(Si,Ge)4(2 mm) / Ag(1 mm)

[0095] Operating frequency: 0.1 Hz

[0096] Adiabatic temperature change during the process of entering the magnetic field: 5 K

[0097] Total length of a refrigeration unit model: 85 mm

[0098] Example 5

[0099] Refrigeration sheet: La(Fe,Si) 13 , Heat conduction sheet: Au

[0100] Number of rectangular refrigeration sheets in each refrigeration layer: 7; Number of rectangular heat conduction sheets in each heat transfer layer: 8. The length and width of the refrigeration sheet and the heat conduction sheet are the same: 3 mm; Thickness: La(Fe,Si) 13 (5 mm) / Au(2 mm)

[0101] Operating frequency: 0.1 Hz

[0102] Adiabatic temperature change during the process of entering the magnetic field: 5 K

[0103] Total length of a refrigeration unit model: 90 mm

[0104] Example 6

[0105] Refrigeration sheet: MnCoGe, Heat conduction sheet: Al

[0106] Number of rectangular refrigeration sheets in each refrigeration layer: 18; Number of rectangular heat conduction sheets in each heat transfer layer: 19. The length and width of the refrigeration sheet and the heat conduction sheet are the same: 1 mm; Thickness: MnCoGe(3 mm) / Al(0.5 mm)

[0107] Operating frequency: 20 Hz

[0108] Adiabatic temperature change during the process of entering the magnetic field: 5 K

[0109] Total length of a refrigeration unit model: 75 mm

[0110] Example 7

[0111] Refrigeration sheet: NiMnSn, Heat conduction sheet: Pt

[0112] Number of rectangular cooling fins in each cooling layer: 15; Number of rectangular heat-conducting fins in each heat-transfer layer: 16. The length and width of the cooling fins and heat-conducting fins are the same: 0.1 mm; The thickness is MnCoGe(0.1 mm) / Al(0.1 mm)

[0113] Operating frequency: 50 Hz

[0114] Adiabatic temperature change during the process of entering the magnetic field: 3 K

[0115] Total length of a cooling unit model: 6.5 mm

[0116] Example 8

[0117] Cooling fin: NiMnSn, Heat-conducting fin: Pt

[0118] Number of rectangular cooling fins in each cooling layer: 15; Number of rectangular heat-conducting fins in each heat-transfer layer: 16. The length and width of the cooling fins and heat-conducting fins are the same: 0.1 mm; The thickness is MnCoGe(0.1 mm) / Pt(0.1 mm)

[0119] Operating frequency: 50 Hz

[0120] Adiabatic temperature change during the process of entering the magnetic field: 3 K

[0121] Total length of a cooling unit model: 6.5 mm

[0122] Example 9

[0123] Cooling fin: NiMnSn, Heat-conducting fin: Fe

[0124] Number of rectangular cooling fins in each cooling layer: 4; Number of rectangular heat-conducting fins in each heat-transfer layer: 5. The length and width of the cooling fins and heat-conducting fins are the same: 10 mm; The thickness is MnCoGe(5 mm) / Fe(0.5 mm)

[0125] Operating frequency: 50 Hz

[0126] Adiabatic temperature change during the process of entering the magnetic field: 3 K

[0127] Total length of a cooling unit model: 170 mm

[0128] Example 10

[0129] Cooling fin: NiMnSn, Heat-conducting fin: Carbon nanotube

[0130] Number of rectangular cooling fins in each cooling layer: 8; Number of rectangular heat-conducting fins in each heat-transfer layer: 9. The length and width of the cooling fins and heat-conducting fins are the same: 3 mm; The thickness is MnCoGe(5 mm) / Carbon nanotube(0.5 mm)

[0131] Operating frequency: 3 Hz

[0132] Adiabatic temperature change during the process of entering the magnetic field: 4 K

[0133] The total length of a refrigeration unit model is: 100 mm

[0134] Example 11

[0135] Refrigerating sheet: Gd, heat conducting sheet: graphene

[0136] The number of rectangular refrigerating sheets in each refrigeration layer: 8; the number of rectangular heat conducting sheets in each heat transfer layer: 9. The length and width of the refrigerating sheet and the heat conducting sheet are the same: 3 mm; the thickness is Gd(1 mm) / graphene(3 mm)

[0137] Operating frequency: 15 Hz

[0138] Adiabatic temperature change during the process of entering the magnetic field: 8 K

[0139] The total length of a refrigeration unit model is: 100 mm

[0140] Example 12

[0141] Refrigerating sheet: Gd, heat conducting sheet: graphene

[0142] The number of rectangular refrigerating sheets in each refrigeration layer: 8; the number of rectangular heat conducting sheets in each heat transfer layer: 9. The length and width of the refrigerating sheet and the heat conducting sheet are the same: 3 mm; the thickness is Gd(1 mm) / graphene(3 mm)

[0143] Operating frequency: 15 Hz

[0144] Adiabatic temperature change during the process of entering the magnetic field: 8 K

[0145] The total length of a refrigeration unit model is: 100 mm

[0146] Example 13

[0147] Refrigerating sheet: Gd, heat conducting sheet: graphene

[0148] The number of rectangular refrigerating sheets in each refrigeration layer: 8; the number of rectangular heat conducting sheets in each heat transfer layer: 9. The length of the refrigerating sheet and the heat conducting sheet is the same: 3 mm; the width of the refrigerating sheet and the heat conducting sheet is the same: 5 mm; the thickness is Gd(1 mm) / graphene(3 mm)

[0149] Operating frequency: 15 Hz

[0150] Adiabatic temperature change during the process of entering the magnetic field: 8 K

[0151] The total length of a refrigeration unit model is: 100 mm

[0152] Example 14

[0153] Thermoelectric cooler: MnCoGe, heat sink: Al

[0154] Number of rectangular thermoelectric coolers in each cooling layer: 18; Number of rectangular heat sinks in each heat transfer layer: 19. The length of the thermoelectric cooler and the heat sink is the same: 1 mm; The width of the thermoelectric cooler and the heat sink is the same: 3 mm; Thickness: MnCoGe(3 mm) / Al(0.5 mm)

[0155] Operating frequency: 20 Hz

[0156] Adiabatic temperature change during the process of entering the magnetic field: 5 K

[0157] Total length of a refrigeration unit model: 75 mm

[0158] Example 15

[0159] Thermoelectric cooler: Gd, heat sink: Cu

[0160] Number of rectangular thermoelectric coolers in each cooling layer: 4; Number of rectangular heat sinks in each heat transfer layer: 5. The length of the thermoelectric cooler and the heat sink is the same: 3 mm; The width of the thermoelectric cooler and the heat sink is the same: 1 mm; Thickness: Gd(0.2 mm) / Cu(0.1 mm)

[0161] Operating frequency: 7 Hz

[0162] Adiabatic temperature change generated during the process of entering the magnetic field: 5 K

[0163] Total length of a refrigeration unit model: 47 mm

[0164] Example 16

[0165] Thermoelectric cooler: Gd, heat sink: Cu

[0166] Number of rectangular thermoelectric coolers in each cooling layer: 4; Number of rectangular heat sinks in each heat transfer layer: 5. The length of the thermoelectric cooler and the heat sink is the same: 3 mm; The width of the thermoelectric cooler and the heat sink is the same: 1 mm; Thickness: Gd(1.5 mm) / Cu(0.1 mm)

[0167] Operating frequency: 13 Hz

[0168] Adiabatic temperature change generated during the process of entering the magnetic field: 5 K

[0169] Total length of a refrigeration unit model: 47 mm

[0170] Example 17

[0171] Thermoelectric cooler: Gd, heat sink: diamond aluminum alloy

[0172] Number of rectangular thermoelectric coolers in each cooling layer: 8; Number of rectangular heat sinks in each heat transfer layer: 9. The length of the thermoelectric cooler and the heat sink is the same: 3 mm; The width of the thermoelectric cooler and the heat sink is the same: 5 mm; Thickness is Gd(1 mm) / diamond aluminum alloy(3 mm)

[0173] Operating frequency: 15 Hz

[0174] Adiabatic temperature change during the process of entering the magnetic field: 3 K

[0175] Total length of a refrigeration unit model: 100 mm

[0176] Refrigeration performance simulation results

[0177] Examples 1-17 all showed good refrigeration effects. Hereinafter, the simulation effects of Example 1 are exemplarily given.

[0178] 1) Refrigeration temperature span without load

[0179] The model of Example 1 uses tetrahedral elements for adaptive free mesh generation. The mesh model is as Figure 3 shown. Only the lower surface of the cooling layer and the upper surface of the heat conduction layer can conduct heat, and the rest of the boundaries are adiabatic boundaries. In order to describe the reverse reciprocating motion of the cooling layer and the heat conduction layer, a dynamic mesh boundary condition is defined in the model. It is set that the cooling layer and the heat conduction layer reciprocate with a period of 0.1 s (frequency of 10 Hz), and a total of 90 cycles are performed. The total calculation time domain is 9 s. Transient solution is adopted, the calculation time domain is one cycle period of 0.1 s, the maximum time step is 0.0003 s, the total time is 9 s, and a direct strong coupling solver is used to solve, combined with the nonlinear Newton iteration method, and the convergence factor is 0.01. For the solution of the refrigeration temperature span of the device under no-load conditions.

[0180] In Example 1, the numbers of rectangular refrigeration modules and regenerative modules are set to 4 and 5 respectively. Its geometric model is as Figure 1As shown. The initial temperatures of all refrigeration layers and heat conduction layers are set to 295K. The cold end and the hot end are separated at the two moving terminals of the heat conduction layer. Among them, the temperature of the refrigeration module will increase by 3K when it enters the magnetic field region, and the temperature of the refrigeration module will decrease by 3K when it leaves the magnetic field region. With the reverse reciprocating movement of the refrigeration layer and the heat conduction layer, the heat transfer material of the refrigeration module comes into contact with the heat regenerator module for heat exchange, resulting in continuous temperature changes of each refrigeration module and heat regenerator module. As the cycle progresses, the temperature finally reaches stability. The temperature difference between the hot end and the cold end at steady state is the maximum temperature span of this all-solid-state magnetic refrigeration model device under no-load conditions. Based on the established finite element simulation model above, through the setting and calculation of initial parameters, as the cycle continues, the temperature distribution of the refrigeration working medium gradually tends to be stable. To more clearly see the temperature changes at the hot and cold ends and each refrigeration module at stability, the temperature-time change curve at stability is shown in Figure 4 where the top and bottom horizontal lines are the hot end and the cold end respectively, and the four fluctuating curves in the middle from top to bottom correspond to 4 cooling fins from right to left. It can be seen that the hot end temperature stabilizes at about 301.5K, the cold end temperature stabilizes at about 289.5K, and the formed 12K temperature span corresponds to 4 cooling fins. The maximum no-load temperature span of the device when the adiabatic temperature change of the cooling fin is 3K, thus proving that the all-solid-state magnetic refrigeration model device designed in this paper can form a large refrigeration temperature span under the condition of limited adiabatic temperature change.

[0181] 2) Influence of the thickness of the heat conduction layer on the temperature span and relaxation time

[0182] To study the influence of the thickness of the heat conduction layer on the temperature span and relaxation time, based on the established finite element simulation model above, the maximum temperature span of this device and the relaxation time at equilibrium were calculated under different thicknesses of the heat transfer layer Cu from 0.04 to 0.2mm as Figure 5 shown. It can be seen that the change in the thickness of Cu basically does not affect the maximum temperature span at equilibrium, but it will affect the relaxation time at equilibrium. When the thickness of copper is very thin, the heat-carrying capacity of Cu is very low, which leads to a longer time required to form the equilibrium temperature span; similarly, when copper is relatively thick, due to the relatively high movement frequency, the heat regeneration process is incomplete, resulting in a longer time required to form the equilibrium temperature span. Therefore, when the thickness of the Gd layer is 0.2mm, the optimal thickness of the Cu layer we obtained is 0.08mm, and the relaxation time to form the equilibrium temperature span is the shortest at this time.

[0183] 3) Influence of adiabatic temperature change and the number of refrigeration modules on the temperature span

[0184] To study the influence of the adiabatic temperature change of the refrigeration working medium and the number of modules on the refrigeration temperature span of the entire refrigeration system under no-load conditions, based on the established finite element simulation model above, the adiabatic temperature change ΔT generated under different magnetic fields was calculatedMCE The effects of 6K, 5K, 4K, 3K, and 2K on the maximum refrigeration temperature span are as Figure 6 shown, as well as the effects of different numbers of refrigeration chips, NS = 2, 3, 4, 5, and 6, on the maximum refrigeration temperature span, as Figure 7 shown. From the above two figures, a very simple and intuitive rule can be summarized. At equilibrium, the maximum refrigeration temperature span is equal to the number of refrigeration chips multiplied by the adiabatic temperature change. The regenerative factor r = ΔT span / ΔT MCE can also be calculated from the figure. In fact, r is an important parameter for measuring the regenerative performance of a refrigeration device. For N S = 4, r = 4, which is much larger than the reported 2 - 2.4 in the literature. The significant improvement of r for this device is of great significance for the development of practical magnetic refrigeration devices. This is because, although the adiabatic temperature change of magnetic refrigeration materials reported in the literature in the past few decades can reach 20K, usually a relatively high magnetic field is required, which brings great difficulties to the design and cost of magnetic refrigeration devices. Therefore, it is of great significance to design a device configuration that can provide a larger ΔT MCE under a limited ΔT span , which is particularly attractive.

[0185] 4) Effects of working frequency on temperature span and relaxation time

[0186] To study the effects of the frequency of the all - solid - state refrigeration model device designed in the present invention on the temperature span and relaxation time, based on the finite - element simulation model established above, the equilibrium temperature span and relaxation time of the device at different working frequencies were calculated, as Figure 8 shown. It can be seen that frequencies below 50Hz have no effect on the equilibrium temperature span of the device, but the relaxation time decreases as the frequency increases. When the frequency is higher than 50Hz, reaching 1000Hz or even 10000Hz, it may have a certain impact on the equilibrium temperature span of the device due to the too - short heat - exchange time, and the calculation here is not complete.

[0187] 5) Refrigeration capacity

[0188] To study the refrigeration capacity of the all - solid - state magnetic refrigeration model device designed in this paper, based on the finite - element simulation model with the number of refrigeration modules N S = 4 (very easy to manufacture) and ΔT MCE = 3K (easily obtained through permanent magnets), by changing the boundary conditions, that is, giving a heating power to the cold end and making the hot end an infinite heat source fixed at 295K, the results as shown in Figure 9The data shown. It can be seen that a refrigeration power corresponds to a balanced temperature span, and the maximum power of this device can reach 4 mW. To increase the power, on the one hand, the operating frequency can be increased, on the other hand, the area of the refrigeration block can be increased, or multiple layers of refrigeration units can be stacked.

[0189] The present invention proposes a fully solid-state magnetic refrigeration device composed of a combination of a magnetic refrigeration working medium and a high-thermal-conductivity material without an external regenerator. Its core components are a refrigeration layer composed of magnetic refrigeration working media connected by adiabatic materials and a heat-conducting layer composed of high-thermal-conductivity materials connected by adiabatic materials, which are composed of two layers. They are arranged alternately from top to bottom, and the refrigeration layer and the heat-conducting layer move reciprocally in opposite directions in parallel to achieve heat regeneration and refrigeration. Its heat regeneration process is realized by the direct heat exchange between the refrigeration module and the heat regeneration module in two adjacent refrigeration layers and heat-conducting layers. Since there is no external heat regeneration module, irreversible heat loss is eliminated, thereby providing a high cooling power density for this device. At the same time, taking advantage of the high thermal conductivity of the high-thermal-conductivity material, heat can be quickly exchanged between the refrigeration layer and the heat-conducting layer, enabling the refrigeration device to have excellent cooling power density at high operating frequencies. In addition, the unique heat regeneration process of this device makes its refrigeration temperature span much larger than the adiabatic temperature change of single-element magnetic refrigeration materials (when the number of magnetic thermal blocks in a single layer N S = 4, the heat regeneration coefficient r = 4), providing a feasible and effective new way for developing high-performance magnetic refrigerators using existing magnetic refrigeration materials.

Claims

1. A reciprocating all-solid-state magnetic refrigeration device, which comprises: At least one refrigeration unit, the refrigeration unit including a refrigeration layer and a heat conduction layer arranged in parallel, wherein the refrigeration layer includes a plurality of magnetic refrigeration working medium sheets spacedly embedded in a first heat insulation material, and the heat conduction layer includes a plurality of heat conduction working medium sheets spacedly embedded in a second heat insulation material, wherein the arrangement of the refrigeration unit enables the refrigeration layer and the heat conduction layer to perform reverse reciprocating translational motion, and there is heat conduction between the magnetic refrigeration working medium sheets and the heat conduction working medium sheets; and A device for providing a discontinuous segmented magnetic field, the discontinuous segmented magnetic field enabling all of the plurality of magnetic refrigeration working medium sheets to be within the magnetic field in one terminal state of the reciprocating translational motion of the refrigeration layer, and enabling all of the plurality of magnetic refrigeration working medium sheets to be outside the magnetic field in another terminal state; wherein the reverse reciprocating translational motion of the refrigeration layer and the heat conduction layer has the same frequency; Wherein the heat conduction layer includes a cold-end heat conduction working medium sheet and a hot-end heat conduction working medium sheet respectively close to two motion terminals of the heat conduction layer.

2. The reciprocating all-solid-state magnetic refrigeration device according to claim 1, wherein, The arrangement of the refrigeration unit enables each of the plurality of magnetic refrigeration working medium sheets to sequentially conduct heat with two adjacent heat conduction working medium sheets among the plurality of heat conduction working medium sheets during the reciprocating translational motion.

3. The reciprocating all-solid-state magnetic refrigeration device according to claim 1, wherein, The material of the magnetic refrigeration working medium sheet is one or more of Gd, FeRh, LaFeSi, GdSiGe, MnAs, MnPSiGe, and NiMnX; the material of the heat conduction working medium sheet is one or more of copper, silver, gold, aluminum, platinum, iron, graphene, carbon nanotubes, and diamond aluminum alloy.

4. The reciprocating all-solid-state magnetic refrigeration device according to claim 1, wherein, The first heat insulation material and the second heat insulation material are the same or different, and are each independently selected from one or more of fiberglass, asbestos, rock wool, silicate, aerogel felt, and vacuum panel.

5. The reciprocating all-solid-state magnetic refrigeration device according to claim 3, wherein, The material of the magnetocaloric refrigerant sheet is one or more of Gd, Gd5(Si, Ge)4, La(Fe, Si) 13 , MnCoGe, and NiMnSn.

6. The reciprocating all-solid-state magnetic refrigeration device according to claim 3, wherein, The material of the heat conduction working medium sheet is copper or graphene.

7. The reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 6, wherein, The distance between the refrigeration layer and the heat conduction layer is 0 to 10 nm.

8. The reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 6, wherein, Graphite powder is provided between the refrigeration layer and the heat conduction layer.

9. The reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 6, wherein, The magnetic refrigeration device includes 1 to 100 of the refrigeration units.

10. The reciprocating all-solid-state magnetic refrigeration device according to claim 9, wherein, The magnetic refrigeration device includes 2 to 25 of the refrigeration units.

11. The reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 6, wherein, The refrigeration layer includes 2 to 100 magnetic refrigeration working medium sheets; the heat conduction layer includes 2 to 100 heat conduction working medium sheets.

12. The reciprocating all-solid-state magnetic refrigeration device according to claim 11, wherein, The refrigeration layer includes 4 to 25 magnetic refrigeration working medium sheets; the heat conduction layer includes 4 to 25 heat conduction working medium sheets.

13. The reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 6, wherein, The number of magnetic refrigeration working medium sheets included in the refrigeration layer is one less than the number of heat conduction working medium sheets included in the heat conduction layer.

14. Application of the reciprocating all-solid-state magnetic refrigeration device according to any one of claims 1 to 13 in refrigerators, air conditioners, liquefied gases, and microelectronic device refrigeration.

15. The application according to claim 14, wherein the application includes placing the reciprocating all-solid-state magnetic refrigeration device in a discontinuous segmented magnetic field, such that in one terminal state of the reciprocating translational motion, all of the plurality of magnetic refrigeration working fluid sheets are within the magnetic field, and in another terminal state, all of the plurality of magnetic refrigeration working fluid sheets are outside the magnetic field; wherein, The reverse reciprocating translational motion of the refrigeration layer and the heat conduction layer has the same frequency.

16. The application according to claim 15, wherein, The intensity of the magnetic field is 0.1 to 60 T.

17. The application according to claim 16, wherein, The intensity of the magnetic field is 0.5 T to 2 T.

18. The application according to claim 15, wherein The frequency of the reciprocating translational motion is 0.01 to 1000 Hz.

19. The application according to claim 18, wherein, The frequency of the reciprocating translational motion is 1 to 20 Hz.

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