Single magnetic field operated high efficient regenerative all-solid-state magnetic refrigeration device and application thereof

Abstract

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

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic refrigeration, and relates to a reciprocating all-solid-state magnetic refrigeration device with high-efficiency regeneration realized by using a single magnetic field without the assistance of a regenerator and application thereof. BACKGROUND

[0002] Magnetic refrigeration technology is a technology for realizing refrigeration by using the entropy change and temperature change caused by the phase change of a magnetic refrigerant material in the processes of magnetization and demagnetization. In the process of traditional gas compression refrigeration, a large amount of freon, a refrigerant that destroys ozone layer and causes greenhouse effect, needs to be used; and a magnetic refrigerator using magnetic refrigeration technology does not produce and use chemical substances that destroy the environment, so the magnetic refrigeration technology is a green and environmentally friendly technology.

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

[0004] The regenerator used in a room-temperature magnetic refrigerator can be divided into three forms: an external regenerator, an internal regenerator and an active regenerator. The magnetic material in an active magnetic regenerative (AMR) cycle is both a magnetic refrigerant and a regenerative material, and it becomes the most recognized magnetic refrigeration cycle with the highest energy utilization efficiency at the present stage by virtue of reducing the heat loss in the regeneration process, and has been applied to many refrigeration cycles. The initial traditional AMR cycle is completed by fluid heat exchange, however, in order to meet the characteristics of non-electricity conduction or non-magnetism, the heat conduction performance of the heat exchange fluid is often sacrificed, which limits the heat exchange speed and limits the working frequency of the actual refrigeration device to below 1 Hz, thereby limiting the refrigeration power density. If the working frequency is blindly pursued, the heat conduction will be insufficient, thereby reducing the refrigeration power density and the 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, and the relatively rough mechanical control device of the fluid all have a non-negligible impact on the refrigeration efficiency of the device. In addition, the corrosion problem of the heat exchange fluid to the magnet and the refrigerant also brings difficulties to the design of the magnetic refrigeration device, thereby increasing the manufacturing cost of the refrigeration device.

[0005] To solve the problems brought by traditional AMR based on fluid heat exchange, a new full solid-state magnetic refrigeration model using high thermal conductivity solid heat exchange medium for heat recovery has attracted much attention. Currently reported full solid-state refrigeration models mainly include two types: one is based on thermal diode (electrically controlled thermal diode and magnetically controlled thermal diode) full solid-state magnetic refrigeration model, and the other is based on high thermal conductivity material full solid-state refrigeration model. Among them, the full solid-state magnetic refrigeration model based on thermal diode uses Peltier element (electrically controlled thermal diode) as solid-state heat conducting medium. In order to complete heat conduction faster, a larger working current needs to be input in the Peltier element, thereby increasing the electrical power loss (i.e. external work) of the whole system, resulting in the decrease of the COP (coefficient of performance) of the whole refrigeration system and the reduction of the refrigeration efficiency. If the working current is reduced, the electrical power loss can indeed be reduced, but at the same time, the heat conduction speed is also reduced, the refrigeration capacity is decreased, and the working frequency is reduced, which is contrary to the original intention of introducing thermal diode. Therefore, the introduction of Peltier element can improve the working frequency and refrigeration power of the full solid-state magnetic refrigeration system, but at the same time, the electrical power loss is inevitably introduced, which has a negative impact on the refrigeration efficiency. On the other hand, although the full solid-state refrigeration model based on magnetically controlled thermal diode can greatly improve the power density, COP and refrigeration temperature span, it is difficult to obtain a magnetically controlled thermal diode material that meets the conditions of practical application. In contrast, high thermal conductivity materials can achieve efficient heat conduction without external power driving, and high thermal conductivity materials are easy to obtain. Therefore, the full solid-state magnetic refrigeration device using high thermal conductivity materials for heat recovery can not only improve the refrigeration power and efficiency of the refrigeration device, but also can be truly built and put into practical use.

[0006] The applicant proposes a full solid-state magnetic refrigeration device in another prior application CN202210515054.6 which has not been disclosed yet. The core refrigeration unit of the device includes a plurality of magnetic refrigeration pieces and a heat conducting piece. The heat conducting piece is in contact with each of the plurality of magnetic refrigeration pieces in turn to achieve heat conduction. The maximum heat recovery factor of the device is about 3 calculated by establishing a finite element simulation model. SUMMARY

[0007] Therefore, the purpose of the present application is to design and develop a high-efficiency heat recovery full solid-state magnetic refrigeration device operating under a single magnetic field. In the case of using a single magnet to generate a simple continuous magnetic field, the device takes advantage of the fast heat conduction of high thermal conductivity materials to achieve high-frequency operation while having a simple device design, low production cost, and a heat recovery factor superior to the device proposed in the applicant's prior application CN202210515054.6.

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

[0009] The "high-efficiency heat recovery" described in the present application refers to the heat recovery efficiency of the device of the present application being higher than that of the device proposed in CN202210515054.6 designed by the inventor.

[0010] The inventor of the present application 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, which is an ideal heat recovery working medium; on the other hand, heat insulation materials such as glass fiber, asbestos, rock wool, silicate, aerogel felt, vacuum plate can effectively prevent the magnetic refrigeration working medium and the high thermal conductivity material from exchanging heat with the outside world, thereby reducing heat loss. Therefore, the inventor combines the high thermal conductivity material as the heat recovery working medium with the magnetic refrigeration material and the heat insulation material, and realizes high-efficiency heat recovery of the all-solid-state magnetic refrigeration through reasonable device design. In addition, since the magnetic refrigeration working medium, the heat recovery working medium and the heat insulation material are all solid, they can be designed and processed into different shapes and sizes, and they are also easy to be precisely controlled by mechanical devices. Therefore, the all-solid-state refrigeration device based on high thermal conductivity material can realize refrigeration of devices of different scales (sub-micron to meter).

[0011] The purpose of the present application is achieved by the following technical solutions.

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

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

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

[0015] wherein the number of magnetic refrigeration working medium pieces = the number of heat recovery working medium pieces + 1, and the refrigeration unit is arranged so that the refrigeration layer and the heat recovery layer make reciprocating translational motion respectively when working, and the magnetic refrigeration working medium pieces and the heat recovery working medium pieces have heat conduction therebetween.

[0016] In an embodiment of the present application, the refrigeration unit is arranged so that each of the refrigeration pieces has heat conduction with only two adjacent heat recovery pieces at its opposite position in the reciprocating translational motion; similarly, each of the heat recovery pieces has heat conduction with only two adjacent refrigeration pieces at its opposite position in the reciprocating translational motion.

[0017] In a preferred embodiment of the present application, the size of the refrigeration layer is equal to the size of the regenerative layer; and the size of the magnetic refrigeration working piece is equal to the size of the regenerative working piece.

[0018] In actual use, the two ends of the magnetic refrigeration device provided by the present application are respectively matched with a cold end requiring refrigeration and a hot end requiring heat dissipation. The cold end and the hot end are respectively located at the two motion terminals of the reciprocating translation motion of the device, and at the two motion terminals, the two outermost magnetic refrigeration working pieces of the plurality of magnetic refrigeration working pieces are respectively in heat exchange with the cold end and the hot end.

[0019] In order to facilitate the illustration of the refrigeration capacity of the magnetic refrigeration device of the present application, the cold end and the hot end are set as the pieces of high-thermal-conductivity material which are stationary at the two motion terminals.

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

[0021] The magnetic field can be a common continuous magnetic field. In the most preferred case, the magnetic field is arranged such that in one terminal state of the reciprocating translation motion of the refrigeration layer, all the plurality of refrigeration pieces are in the magnetic field, and in the other terminal state, all the plurality of refrigeration pieces are out of the magnetic field.

[0022] Figure 1 A schematic diagram of the four working states of the magnetic refrigeration device of the present application is drawn. In the refrigeration cycle of the reciprocating motion, each of the plurality of refrigeration pieces of the refrigeration layer reciprocates in the magnetic field region and the non-magnetic field region, and each refrigeration piece is in contact with the cold end or the left regenerative piece when cooling in the non-magnetic field region, and is in contact with the hot end or the right regenerative piece when heating in the magnetic field region, so as to absorb heat from the cold end or the left regenerative piece, and transfer heat to the hot end or the right regenerative piece, so that heat is continuously transported from the cold end to the hot end, and refrigeration is achieved.

[0023] The continuous magnetic field is preferably a uniform magnetic field, and the strength of the magnetic field can be 0.1 to 60T, preferably 0.5T to 3T. The frequency of the reciprocating motion of the refrigeration layer and the regenerative layer can be 0.01 to 1000Hz, preferably 1 to 20Hz. In the 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 application, the magnetic refrigeration working piece can be made of any magnetic heat material, for example, 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.

[0025] According to the magnetic refrigeration device provided by the application, the regenerative working piece can be made of any high-thermal-conductivity material, for example, copper, silver, gold, aluminum, platinum, iron, graphene, diamond aluminum alloy and carbon nanotube, and the like, preferably easily available materials such as copper and graphene.

[0026] The inventor has found through in-depth research that the thickness of the regenerative working piece has a relatively obvious influence on the temperature span after multiple cycles. When the thickness of the regenerative working piece is too small, the capacity of carrying heat is too small, which leads to a decrease in the heat transported in each cycle and a decrease in the temperature span. When the thickness of the regenerative working piece is too large, the heat conduction is not complete in each regenerative process, which leads to a decrease in the temperature span. Therefore, the thickness of the regenerative working piece is closely related to the thickness of the refrigeration working piece, the working frequency and the type of material. In the preferred embodiment of the application, the ratio of the thickness of the regenerative working piece to the thickness of the refrigeration working piece is 0.5-3:1.

[0027] According to the high-efficiency regenerative reciprocating full-solid-state magnetic refrigeration device provided by the application, the first thermal insulation material and the second thermal insulation material can be the same or different, and can each be independently selected from one or more of glass fiber, asbestos, rock wool, silicate, aerogel felt and vacuum plate.

[0028] According to the high-efficiency regenerative reciprocating full-solid-state magnetic refrigeration device provided by the application, the refrigeration piece can be embedded in the first thermal insulation material of the refrigeration layer or the regenerative piece can be embedded in the second thermal insulation material of the regenerative layer by any known method, for example, using epoxy resin adhesive. The refrigeration layer and the regenerative layer can be assembled together by any known method, as long as the refrigeration layer and the regenerative layer can independently move in translation, for example, the regenerative layer and the refrigeration layer can each be controlled by a single linear stepping motor.

[0029] In the preferred embodiment of the application, in order to have the best heat conduction between the refrigeration layer and the regenerative layer and reduce the additional loss caused by the friction force work, graphite powder or other heat-conducting material powder is arranged between the refrigeration layer and the regenerative layer. Preferably, the distance between the refrigeration layer and the regenerative layer can be 0-10 nm.

[0030] In some preferred embodiments of the present application, the size of the refrigeration sheet, the size of the regenerative sheet, the size of the first thermal insulation material between two adjacent refrigeration sheets, and the size of the second thermal insulation material between two adjacent regenerative sheets are of the same order of magnitude. In more preferred embodiments, the size of the refrigeration sheet, the size of the regenerative sheet, the size of the first thermal insulation material between two adjacent refrigeration sheets, and the size of the second thermal insulation material between two adjacent regenerative sheets are equal.

[0031] According to the present application, a magnetic refrigeration device is provided, wherein the magnetic refrigeration device can comprise a refrigeration array composed of a plurality of refrigeration units, wherein the plurality of refrigeration units are stacked vertically to form a structure in which refrigeration layers and regenerative layers are arranged alternately. The number of refrigeration units included in the refrigeration array can be selected to be 1-100, such as 2-100, preferably 2-25, according to actual refrigeration requirements.

[0032] In the vertically stacked refrigeration array, the refrigeration layers and the regenerative layers are arranged alternately, i.e., two layers adjacent to each refrigeration layer are regenerative layers, and two layers adjacent to each regenerative layer are refrigeration layers. The number of regenerative layers can be equal to or 1 more or less than the number of refrigeration layers. In addition, the number of refrigeration sheets in each refrigeration layer is the same, and the number of regenerative sheets in each regenerative layer is the same. More preferably, the number of regenerative layers is 1 more than the number of refrigeration layers, so that each refrigeration layer is in contact with two regenerative layers at the same time, further improving the regenerative efficiency.

[0033] The present application does not have special restrictions on the shape of the refrigeration layer, the regenerative layer, the refrigeration sheet, and the regenerative sheet. In preferred embodiments, in order to facilitate manufacturing and control the regenerative effect, the refrigeration layer, the regenerative layer, the refrigeration sheet, and the regenerative sheet are all rectangular with the same size. Preferably, the plurality of refrigeration sheets are embedded in the first thermal insulation material of the refrigeration layer at equal intervals, and the regenerative sheets are embedded in the second thermal insulation material of the regenerative layer at equal intervals. Preferably, the refrigeration layer comprises 2-100 magnetic refrigeration working sheets, more preferably 4-25; the number of regenerative sheets in the regenerative layer is 1 less than the number of refrigeration sheets in the refrigeration layer.

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

[0035] The application includes placing the high-efficiency reciprocating full-solid-state magnetic refrigeration device in a common continuous magnetic field, so that in one terminal state of the reciprocating translational motion, all of the refrigeration pieces are in the magnetic field, and in the other terminal state, all of the refrigeration pieces are out of the magnetic field. Preferably, the strength of the magnetic field is 0.1-60T, more preferably 0.5T-3T. The reciprocating translational motion of the refrigeration layer and the regenerative layer has the same frequency, which is preferably 0.01-1000Hz, more preferably 0.1-20Hz.

[0036] In a preferred embodiment of the application, the application includes matching the magnetic refrigeration device with a cold end requiring refrigeration and a hot end requiring heat dissipation, the cold end and the hot end being located at the two motion terminals of the reciprocating translational motion of the magnetic refrigeration device, and at the two motion terminals, the two outermost magnetic refrigeration working pieces of the plurality of magnetic refrigeration working pieces respectively exchange heat with the cold end and the hot end,

[0037] When the cold end is on the left and the hot end is on the right, the application includes the following operations:

[0038] (1) The refrigeration layer and the regenerative layer are stationary at the cold end motion terminal, and each refrigeration working piece respectively exchanges heat with the left regenerative working piece and the cold end, and absorbs heat from the cold end and the left regenerative working piece;

[0039] (2) The refrigeration layer and the regenerative layer simultaneously move to the hot end and enter the magnetic field, and the moving speed of the refrigeration layer is faster than that of the regenerative layer, and the refrigeration working piece enters the magnetic field to complete the temperature rising process after leaving the cold end and the left regenerative working piece and before contacting the right regenerative working piece and the hot end;

[0040] (3) The refrigeration layer and the regenerative layer are stationary at the hot end motion terminal after entering the magnetic field, and each refrigeration working piece respectively exchanges heat with the right regenerative piece and the hot end, and releases heat to the hot end and the right regenerative piece;

[0041] (4) The refrigeration layer and the regenerative layer simultaneously move to the cold end and leave the magnetic field, and the moving speed of the refrigeration layer is faster than that of the regenerative layer, and the refrigeration working piece completes the temperature lowering process out of the magnetic field after leaving the hot end and the right regenerative piece and before contacting the left regenerative piece and the cold end;

[0042] (5) The above operations are reciprocally switched in the order of (1)-(4), so as to transport heat from the cold end to the hot end and realize refrigeration;

[0043] Alternatively, the application comprises operating in the following sequence: the refrigeration layer and the regenerative layer first enter the magnetic field, stop at the motion terminal of (3), and after initialization is completed by cooling to room temperature, reciprocatingly switch the above operation in the order of (3)-(4)-(1)-(2) to transport heat from the cold end to the hot end to achieve refrigeration.

[0044] Hereinafter, for the sake of simplicity, the magnetic refrigeration device with one refrigeration unit, i.e. one refrigeration layer and one regenerative layer, is taken as an example to combine the preferred working mode and working principle of the device. Figure 1 The preferred working mode and working principle of the device of the present application are described.

[0045] 1) In the state shown in (a) of the figure before the device is operated, the refrigeration layer and the regenerative layer are both stopped at the motion terminal outside the magnetic field, at this time the refrigeration sheet at the leftmost side of the refrigeration layer is in good thermal contact with the cold end, and the other refrigeration sheets are all in good thermal contact with the left regenerative sheet, and the multiple refrigeration sheets and the multiple regenerative sheets are separated by thermal insulation materials and kept thermally insulated. During operation, the refrigeration layer and the regenerative layer will individually reciprocate in translation according to a certain time sequence.

[0046] 2) A single continuous magnetic field is applied by a common permanent magnet or electromagnet, the magnetic field region is constant and is set near the hot end, the magnetic field region is preferably of a length that can just accommodate all the refrigeration sheets at the same time, in one terminal state, multiple refrigeration sheets are in the magnetic field, while in the other terminal state, the refrigeration sheets are all outside the magnetic field.

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

[0048] 4) The cold end and the hot end are respectively set at the two motion terminals of the refrigeration layer. Figure 1 The first terminal state during the operation of the device is also the first working state, as shown in (a) of the figure, at this time each refrigeration sheet in the refrigeration layer is in good thermal contact with the cold end and the left regenerative sheet in the corresponding regenerative layer. Figure 1 The second working state during the operation of the device is shown in (b) of the figure, at this time the refrigeration layer and the regenerative layer simultaneously move to the right into the magnetic field, the speed of the movement of the refrigeration layer is faster than that of the regenerative layer, so that the refrigeration sheets in the refrigeration layer start to warm up after leaving the cold end and the left regenerative sheet and before entering the magnetic field, and the warming up process is completed before contacting the hot end and the right regenerative sheet. The specific movement process is not particularly limited, as long as the two conditions that the refrigeration sheets in the refrigeration layer start to warm up after leaving the cold end and the left regenerative sheet and before entering the magnetic field, and the warming up process is completed before contacting the hot end and the right regenerative sheet are met. Figure 1(c) is another motion terminal of the device during operation, which is also the third working state, at this time, the refrigeration layer and the regenerative layer remain stationary, and each refrigeration sheet in the refrigeration layer maintains good thermal contact with the hot end and the regenerative sheet on the right side, respectively, to transfer heat to the hot end and the regenerative sheet on the right side. Figure 1 (d) shows the fourth working state of the device during operation, the refrigeration layer and the regenerative layer move out of the magnetic field to the left at the same time, wherein the refrigeration sheet of the refrigeration layer cools down after leaving the hot end and the regenerative sheet on the right side, and completes the cooling process before contacting the cold end and the regenerative sheet on the left side. The process of movement is not particularly limited, as long as the two conditions that the refrigeration sheet of the refrigeration layer cools down after leaving the hot end and the regenerative sheet on the right side, and completes the cooling process before contacting the cold end and the regenerative sheet on the left side are met. Finally, the device returns to the terminal shown in (a) again. Figure 1 (a) shows the terminal, the cooled refrigeration sheet absorbs heat from the cold end and the regenerative sheet on the left side, and the heat is transported from the left cold end to the right hot end in a cycle, achieving refrigeration. 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 according to the above working sequence, which can also complete refrigeration.

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

[0050] 6) During the reciprocating motion of the refrigeration layer and the regenerative layer, the heat of the cold end is transferred to the hot end through the high-thermal-conductivity regenerative sheet. Due to the mutual thermal insulation between the multiple refrigeration sheets of the refrigeration layer and the multiple regenerative sheets of the regenerative layer, a temperature gradient is formed between the refrigeration sheets and the regenerative sheets. By increasing the number of refrigeration sheets and regenerative sheets, a cascading effect can be achieved, increasing the temperature span.

[0051] 7) By utilizing the high-thermal-conductivity characteristics of the regenerative layer, the design of multiple regenerative sheets simultaneously regenerating at two motion terminals, the all-solid-state magnetic refrigeration device achieves high regenerative efficiency, thereby achieving high-frequency and high-efficiency refrigeration.

[0052] Compared with the prior patent application CN202110906753.9 of the applicant, the prior application requires multiple magnets to generate multiple continuous magnetic fields; while the present application only needs one magnet, i.e., it can achieve high-efficiency operation with a regenerative factor greater than 1 under a simple continuous magnetic field, which greatly reduces the requirements for magnets and production costs.

[0053] Compared with the prior patent application CN202210515054.6 of the applicant, the prior application has only one regenerative sheet in the device, which makes the regenerative efficiency low, thereby limiting the regenerative factor and the refrigeration power; while the present application uses multiple regenerative sheets, at the two motion terminals of the cold and hot ends, multiple regenerative sheets simultaneously conduct heat conduction, greatly improving the regenerative efficiency, thereby improving the regenerative factor and the refrigeration power, and being more practical. BRIEF DESCRIPTION OF DRAWINGS

[0054] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings, in which:

[0055] Figure 1 Fig. 1 is a schematic diagram of four working states of the magnetic refrigeration device of the present application.

[0056] Figure 2 Fig. 4 is a schematic diagram of the grid division model of the magnetic refrigeration device of the present application using rectangular refrigeration sheets and regenerative sheets for finite element simulation in the embodiment.

[0057] Figure 3 Fig. 5 is a schematic diagram of the temperatures of each refrigeration sheet and the cold and hot ends of the magnetic refrigeration device in the embodiment when thermal equilibrium is reached.

[0058] Figure 4 Fig. 6 is a data graph of the influence of Cu thickness on the regenerative factor in the magnetic refrigeration device of the present application.

[0059] Figure 5 Fig. 7 is a data graph of the influence of Cu thickness on the temperature span after 20 cycles in the magnetic refrigeration device of the present application.

[0060] Figure 6 Fig. 8 is a data graph of the influence of working frequency on the regenerative factor in the magnetic refrigeration device of the present application.

[0061] Figure 7 Fig. 9 is a data graph of the influence of the number of Gd refrigeration sheets on the regenerative factor in the magnetic refrigeration device of the present application.

[0062] Figure 8 Fig. 10 is a graph of the relationship between refrigeration power and equilibrium temperature span in the magnetic refrigeration device of the present application. DETAILED DESCRIPTION

[0063] The present application will be further described in detail below in conjunction with specific embodiments, and the embodiments given are only to illustrate the present application, not to limit the scope of the present application.

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

[0065] The magnetic refrigeration device works under a simple continuous magnetic field generated by a single magnet, comprising a refrigeration unit, which comprises a rectangular refrigeration layer and a rectangular regenerator layer, wherein the rectangular refrigeration layer comprises a plurality of rectangular refrigeration pieces and thermal insulation materials connecting them together, and the rectangular regenerator layer comprises a plurality of rectangular regenerator pieces and thermal insulation materials connecting them together, and the number of regenerator pieces is less than the number of refrigeration pieces by 1. The rectangular refrigeration layer and the rectangular regenerator layer can be moved in a certain direction in sequence. The half region of the area crossed by the reciprocating motion of the full solid-state magnetic refrigeration device near the hot end is placed in the magnetic field.

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

[0067] 1) In the area between the cold end and the hot end (i.e. the area crossed by the device reciprocating motion), a simple continuous magnetic field generated by a single magnet is applied to the half region near the hot end.

[0068] 2) The refrigeration layer and the regenerator layer are rectangular, the total length of the device is 0.5mm-10000mm, preferably 5-200mm, the size of the refrigeration pieces and the regenerator pieces is equal, the length and width are independently 0.1mm-100mm, preferably 1mm-10mm, and the thickness of each layer is selected according to actual needs, which can be selected as 0.01mm-50mm, preferably 0.1-5mm.

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

[0070] 4) The number of refrigeration pieces in the refrigeration layer is 2-100, and the number of regenerator pieces in the regenerator layer is less than the number of refrigeration pieces by 1.

[0071] 5) Thermal insulation module, replaced by thermal insulation boundary in simulation.

[0072] 6) The adiabatic temperature change when the refrigeration pieces enter and move out of the magnetic field is selected as 0.1-20K.

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

[0074] 8) According to the actual refrigeration demand, the initial temperature of the refrigeration layer and the regenerative layer is set to 0.1K-1000K.

[0075] Hereinafter, a case is representatively given to illustrate the simulation method of the magnetic refrigeration device of the present application:

[0076] 1) The refrigeration unit in the model is simply composed of one refrigeration layer and one regenerative layer, the number of rectangular refrigeration pieces in the refrigeration layer is set to 4, the number of rectangular regenerative pieces in the regenerative layer is set to 3, the length and width of the refrigeration pieces and the regenerative pieces are the same, which are 5mm and 3mm respectively, and the geometric model is as shown in Figure 1 , two movement terminals and four movement steps are as shown in the (a)-(d) of Figure 1 . The initial temperature of the refrigeration layer and the regenerative layer is set to 295K, and the cold and hot terminals are located at the two movement terminals of the refrigeration layer, wherein, when the refrigeration layer moves to the right terminal, it enters the continuous magnetic field, and the temperature will increase by 4K; similarly, when the refrigeration layer moves to the left terminal, it moves out of the continuous magnetic field, and the temperature will decrease by 4K.

[0077] 2) Among them, only the refrigeration pieces and the regenerative pieces and the cold and hot terminals can exchange heat when they are in contact, and the rest of the boundary is an adiabatic boundary. In order to describe the reciprocating motion of the upper refrigeration layer and the lower regenerative layer, the dynamic grid boundary condition is defined in the model, and the upper refrigeration layer and the lower regenerative layer are set to reciprocate at 1s as a cycle (frequency of 1Hz), a total of 100 cycles, and the total calculation time domain is 100s.

[0078] 3) The model adopts tetrahedral elements for free grid division, and the grid model is as shown in Figure 2 .

[0079] 4) The model adopts transient solution, the calculation time domain is 1s as a cycle, the time step is not more than 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, through the setting calculation of the initial parameters, the temperature difference distribution of the refrigeration pieces, the regenerative pieces and the cold and hot terminals in the device gradually tends to be stable with continuous cycles. In order to more clearly see the temperature change of the magnetic refrigeration device with time, the temperature change curve of the cold and hot terminals and each refrigeration piece after stabilization with time is shown in Figure 3In the figure, the upper and lower horizontal lines represent the hot and cold ends, respectively. 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 results when the cooling plate Gd is 1mm thick and the regenerative plate Cu is 1.4mm thick. The hot end temperature is stable at approximately 303.7K, and the cold end temperature is stable at approximately 287.3K. The resulting 16.4K temperature span corresponds to the four cooling plates. The maximum no-load temperature span of the device is achieved when the cooling plate temperature is adiabatically reduced to 4K. The regenerative factor is 4.1, far greater 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, as follows: Figure 4 As shown in the figure, it can be seen that the thickness of Cu has little effect on the heat recovery factor, which is around 4. This shows that 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 was calculated when the thermal conductive material Cu had different thicknesses of 0.7-1.9 mm. 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 heat carrying capacity of the Cu sheet is too small, resulting in a decrease in the 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 incomplete during each reheating process, causing the temperature span to decrease. Therefore, when the thickness of the cooling sheet is fixed, the reheat sheet should have an optimal thickness. Here, the optimal thickness of the Cu sheet is 1.4mm. In summary, the thickness of the reheat layer will not affect the reheat factor, but it will affect the rate of heat transport, that is, it will affect the cooling power and cooling efficiency of the device. Therefore, in the actual cooling process, the thickness of the reheat layer should be selected to be 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 Cu thickness is fixed at 1.4 mm, the regenerative factor remains essentially unchanged at different frequencies, remaining around 4. This indicates that the regenerative factor of the device is not dependent on the operating frequency.

[0084] The device in the prior application CN202210515054.6 has only one copper sheet for heat recovery, and because the heat recovery speed is very slow, the heat recovery factor is highly dependent on the frequency. Similarly, the four Gd sheets of the same size are used as the refrigeration sheet, and the adiabatic temperature change is also 4K. The heat recovery factor is less than 2 at 1Hz, and the maximum heat recovery factor is only 3 at 0.1Hz. In contrast, the design of multiple heat recovery sheets in the present application greatly improves the heat recovery speed, so that the heat recovery factor is not only independent of the frequency, but also reaches 4 with four refrigeration sheets, which is significantly higher than the previous device, proving that the design of the present application 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 refrigeration sheets is calculated, as shown in Figure 7 . The thickness of Cu is fixed at 1.4mm, and the number of Gd sheets is changed. 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 refrigeration sheets, and is independent of the thickness of the heat recovery layer and the working frequency. In order to obtain a larger heat recovery factor, the number of refrigeration sheets can be appropriately increased.

[0086] 10) Based on the finite element simulation model established above, the thickness of Cu is fixed at 1.4mm, the temperature of the hot end is fixed, and a load is applied at the cold end, so as to study the refrigeration capacity of the device, as shown in Figure 8 . It can be seen that the refrigeration power and the balanced temperature span have a good linear relationship. The maximum refrigeration power of the device is more than 0.06W at a working frequency of 1Hz.

[0087] Hereinafter, the composition, thickness, number of sheets, working frequency and adiabatic temperature change of the magnetic refrigeration working medium during the process of entering the magnetic field of the refrigeration unit used in each embodiment are specifically described. The number of magnets used is 1.

[0088] Example 1

[0089] Refrigeration sheet: Gd, heat recovery sheet: Cu

[0090] Number of rectangular refrigeration sheets in the refrigeration layer: 4; number of rectangular heat recovery sheets in the heat recovery layer: 3;

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

[0092] Operating frequency: 1Hz

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

[0094] Example 2

[0095] Refrigeration plate: Gd, heat regenerator plate: Cu

[0096] Number of rectangular refrigeration plates in the refrigeration layer: 4; number of rectangular heat regenerator plates in the heat regenerator layer: 3;

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

[0098] Operating frequency: 1 Hz

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

[0100] Example 3

[0101] Refrigeration plate: Gd, heat regenerator plate: Cu

[0102] Number of rectangular refrigeration plates in the refrigeration layer: 6; number of rectangular heat regenerator plates in the heat regenerator layer: 5;

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

[0104] Operating frequency: 1 Hz

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

[0106] Example 4

[0107] Refrigeration plate: Gd, heat regenerator plate: Cu

[0108] Number of rectangular refrigeration plates in each refrigeration layer: 4; number of rectangular heat regenerator plates in each heat regenerator layer: 3; thickness: Gd (1 mm) / Cu (1.4 mm)

[0109] Operating frequency: 0.1 Hz

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

[0111] Example 5

[0112] Refrigeration plate: Gd, heat regenerator plate: Cu

[0113] Number of rectangular refrigeration plates in each refrigeration layer: 5; number of rectangular heat regenerator plates in each heat regenerator layer: 4;

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

[0115] Operating frequency: 1 Hz

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

[0117] Example 6

[0118] Refrigeration plate: FeRh, Heat regenerator plate: Ag

[0119] Number of rectangular refrigeration plates in refrigeration layer: 2; Number of rectangular heat regenerator plates in heat regenerator layer: 1;

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

[0121] Operating frequency: 0.01 Hz

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

[0123] Example 7

[0124] Refrigeration plate: LaFeSi, Heat regenerator plate: Au

[0125] Number of rectangular refrigeration plates in refrigeration layer: 5; Number of rectangular heat regenerator plates in heat regenerator layer: 4;

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

[0127] Operating frequency: 0.02 Hz

[0128] Adiabatic temperature change during LaFeSi entering magnetic field: 6 K

[0129] Example 8

[0130] Refrigeration plate: GdSiGe, Heat regenerator plate: Al

[0131] Number of rectangular refrigeration plates in refrigeration layer: 10; Number of rectangular heat regenerator plates in heat regenerator layer: 9;

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

[0133] Operating frequency: 0.05 Hz

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

[0135] Example 9

[0136] Refrigeration plate: MnAs, Heat regenerator plate: Pt

[0137] Number of rectangular refrigeration plates in refrigeration layer: 20; Number of rectangular heat regenerator plates in heat regenerator layer: 19;

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

[0139] Operating frequency: 0.2 Hz

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

[0141] Example 10

[0142] Refrigerant: MnPSiGe, Regenerator: Fe

[0143] Number of rectangular refrigerant pieces in the refrigeration layer: 50; Number of rectangular regenerator pieces in the regenerator layer: 49;

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

[0145] Operating frequency: 0.5 Hz

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

[0147] Example 11

[0148] Refrigerant: NiMnSn, Regenerator: Graphene

[0149] Number of rectangular refrigerant pieces in the refrigeration layer: 100; Number of rectangular regenerator pieces in the regenerator layer: 99;

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

[0151] Operating frequency: 2 Hz

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

[0153] Example 12

[0154] Refrigerant: MnAs, Regenerator: Diamond Aluminum Alloy

[0155] Number of rectangular refrigerant pieces in the refrigeration layer: 13; Number of rectangular regenerator pieces in the regenerator layer: 12;

[0156] Thickness: MnAs (50 mm) / Diamond Aluminum Alloy (40 mm)

[0157] Operating frequency: 5 Hz

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

[0159] Example 13

[0160] Refrigerant: FeRh, Regenerator: Fe

[0161] Number of rectangular refrigerant pieces in the refrigeration layer: 24; Number of rectangular regenerator pieces in the regenerator layer: 23;

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

[0163] Operating frequency: 10Hz

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

[0165] Example 14

[0166] Refrigerant: LaFeSi, Regenerator: Carbon nanotube

[0167] Number of rectangular refrigerant pieces in refrigerant layer: 35; Number of rectangular regenerator pieces in regenerator layer: 34;

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

[0169] Operating frequency: 1000Hz

[0170] Adiabatic temperature change of LaFeSi during entering magnetic field: 3K

[0171] Example 15

[0172] Refrigerant: Gd, Regenerator: Graphene

[0173] Number of rectangular refrigerant pieces in refrigerant layer: 67; Number of rectangular regenerator pieces in regenerator layer: 66;

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

[0175] Operating frequency: 50Hz

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

[0177] Example 16

[0178] Refrigerant: Gd, Regenerator: Ag

[0179] Number of rectangular refrigerant pieces in refrigerant layer: 73; Number of rectangular regenerator pieces in regenerator layer: 72;

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

[0181] Operating frequency: 100Hz

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

[0183] Example 17

[0184] Refrigerant: GdSiGe, Regenerator: Carbon nanotube

[0185] Number of rectangular refrigeration pieces in refrigeration layer: 85; Number of rectangular regenerator pieces in regenerator layer: 84;

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

[0187] Operating frequency: 500Hz

[0188] Adiabatic temperature change of GdSiGe in the process of entering the magnetic field: 6K

[0189] Refrigeration performance simulation results

[0190] Examples 1-17 all show good refrigeration effect. Hereinafter, the simulation effect of Examples 1-4 is exemplarily given.

[0191] 1) No-load refrigeration temperature span

[0192] In Example 1-3, the simple continuous magnetic field generated by the set single magnet occupies half of the reciprocating motion area of the device, the rectangular heat conduction module is 3 pieces, and the rectangular refrigeration module is 4 pieces, and the geometric model is as shown in Figure 1 The initial temperature of all refrigeration layers and regenerator layers is set to 295K, and the cold end and the hot end are separated at the two motion terminals of the refrigeration layer, wherein the temperature of the refrigeration module will increase by 4K when it enters the magnetic field region, and the temperature of the refrigeration module will decrease by 4K when it leaves the magnetic field region. With the reciprocating motion of the refrigeration layer and the regenerator layer in order, the refrigeration pieces and the regenerator pieces and the cold and hot ends are in contact at the two motion terminals for heat exchange, thereby causing the temperature of each refrigeration module and regenerator module to change constantly. With the circulation, the temperature eventually 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 the high-efficiency regenerative all-solid-state magnetic refrigeration model device under no-load condition. Based on the finite element simulation model established above, through the setting of initial parameters for calculation, with the continuous circulation, the temperature distribution of the refrigeration working medium gradually tends to be stable. In order to more clearly see the temperature change of the cold and hot ends and each refrigeration piece at the stable state, the temperature change curve of Example 1 with time at the stable state is shown in Figure 3In the middle, the upper and lower horizontal lines are the hot end and the cold end respectively, and the four wavy curves from top to bottom correspond to the four cooling pieces from right to left, it can be seen that the hot end temperature is stabilized at about 303.7K, and the cold end temperature is stabilized at about 287.3K, and the formed 16.4K temperature span corresponds to the four cooling pieces, that is, the maximum temperature span of the device without load when the adiabatic temperature change of the cooling piece is 4K, thereby proving that the designed full solid-state magnetic refrigeration model device can form a large refrigeration temperature span under the condition of limited adiabatic temperature change. The regeneration factor is defined as the ratio of the equilibrium temperature span to the adiabatic temperature change, and the regeneration factor corresponding to the four cooling pieces is 16.4K / 4K=4.1, which is not only much higher than 1, but also greater than the maximum regeneration factor 3 obtained in the prior application CN202210515054.6 at a working frequency of 0.1Hz, proving that the design greatly improves the regeneration efficiency of the device.

[0193] 2) Influence of regenerator layer thickness on regeneration factor and refrigeration capacity

[0194] In order to study the influence of the thickness of the regenerator layer on the regeneration factor, based on the above established finite element simulation model, the regeneration factor of Example 1 under different thicknesses of the heat transfer layer Cu 0.7-1.9mm is calculated as shown in Figure 4 It can be seen that the thickness of the regenerator piece has little effect on the refrigeration factor of the device, proving that the regeneration factor of the device is independent of the thickness of the regenerator piece. In order to further verify the influence of the thickness of the regenerator piece on the refrigeration capacity of the device, Figure 5 the influence of different Cu piece thicknesses on the cold-hot end temperature difference after 20 cycles is shown. It can be seen that when the regenerator layer is too thin, the heat carrying capacity of the regenerator layer is too weak, and the heat transported in each cycle is too small, resulting in a decrease in the cold-hot end temperature difference; and when the regenerator layer is too thick, the heat exchange between the regenerator layer and the two terminals and the cooling layer is not complete, and the heat transported in each cycle is reduced, resulting in a decrease in the cold-hot end temperature difference. Therefore, the thickness of the regenerator layer has no effect on the regeneration factor of the device, but has a significant effect on the refrigeration capacity of the device.

[0195] 3) Influence of working frequency on regeneration factor

[0196] In order to study the influence of the working frequency of the device on the equilibrium temperature span, based on the finite element simulation model of the refrigeration module N S =4 (very easy to manufacture), ΔT MCE =4K (easily obtained by permanent magnet) of the above Example 1, the thickness of the regenerator layer Cu is set to 1.4mm, and the working frequency is changed. It can be seen from Figure 6 that as the working frequency increases, the regeneration factor does not change significantly, all around 4. Therefore, the regeneration factor of the device is independent of the size of the working frequency.

[0197] 3) Effect of the number of cold plates on the regenerative factor

[0198] To study the effect of the number of cold plates on the equilibrium temperature span in the magnetic refrigeration device of the present application, a finite element simulation model with a regenerative layer thickness of 1.4 mm, ΔT MCE = 4 K, and a working frequency of 1 Hz was established based on the above-mentioned embodiment 1, and the number of cold plates was changed to study the effect of the number of cold plates on the regenerative factor. It can be seen from Figure 7 that the regenerative factor and the number of cold plates have a good linear relationship, and the size of the regenerative factor is basically equal to the number of cold plates. In summary, the regenerative factor of the device is independent of the thickness of the regenerative layer and the working frequency, and only depends on the number of cold plates. In the prior application CN202210515054.6, there is only one copper plate for regenerative heat, and because the regenerative speed is very slow, the regenerative factor is highly dependent on the frequency. Similarly, there are 4 Gd cold plates of the same size, and the adiabatic temperature change is also 4 K. The regenerative factor at 1 Hz is less than 2, and the maximum regenerative factor at 0.1 Hz is only 3. In contrast, the design of multiple regenerative plates in the present application greatly improves the regenerative speed, making the regenerative factor not only independent of the frequency, but also reaching 4 with 4 cold plates, which is significantly higher than the prior application, proving that the design of the present application effectively improves the regenerative efficiency.

[0199] 4) Refrigeration temperature span with load

[0200] To study the refrigeration temperature span of the magnetic refrigeration device of the present application under load, a finite element simulation model with N S = 4, ΔT MCE = 4 K, and a regenerative layer Cu plate thickness of 1.4 mm and a working frequency of 1 Hz was established based on the above-mentioned embodiment 1, the temperature of the hot end was fixed, and a load was added at the cold end to study the refrigeration temperature span of the device under load. It can be seen from Figure 8 that the equilibrium temperature span decreases linearly with the increase of the load, and the refrigeration power of the device at a working frequency of 1 Hz exceeds 0.06 W.

Claims

1. A single magnetic field operated high efficiency regenerative all-solid-state magnetic refrigeration device, comprising at least one refrigeration unit, the refrigeration unit comprising a refrigeration layer and a regenerative layer arranged in parallel, wherein: the refrigeration layer comprises a plurality of magnetic refrigerant pieces embedded in a first thermal insulation material at intervals; the regenerative layer comprises a plurality of regenerative pieces embedded in a second thermal insulation material, wherein the number of magnetic refrigerant pieces = the number of regenerative pieces + 1, the refrigeration unit is arranged such that the refrigeration layer and the regenerative layer make reciprocating translational motion respectively when working, and there is heat conduction between the magnetic refrigerant pieces and the regenerative pieces; wherein each of the magnetic refrigerant pieces exchanges heat with only two adjacent regenerative pieces in its opposite position in the reciprocating translational motion; each of the regenerative pieces exchanges heat with only two adjacent magnetic refrigerant pieces in its opposite position in the reciprocating translational motion. the refrigeration layer and the regenerative layer are equal in size; the magnetic refrigerant pieces and the regenerative pieces are equal in size. The material of the magnetic refrigerant pieces is one or more of Gd, FeRh, LaFeSi, GdSiGe, MnAs, MnPSiGe and NiMnX; the material of the regenerative pieces is one or more of copper, silver, gold, aluminum, platinum, iron, graphene, carbon nanotubes and diamond aluminum alloy. The ratio of the thickness of the regenerative pieces to the thickness of the refrigeration pieces is 0.5-3:

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

2. The magnetic refrigerator device of claim 1, wherein, The distance between the refrigeration layer and the regenerative layer is 0-10 nm.

3. The magnetic refrigerator device of claim 1, wherein, Graphite powder is arranged between the refrigeration layer and the regenerative layer.

4. The magnetic refrigerator device of claim 3, wherein, The material of the magnetic refrigeration medium is Gd, Gd5(Si,Ge)4, La(Fe,Si) 13 , MnCoGe and NiMnSn; the material of the heat recovery working medium sheet is copper or graphene.

5. The magnetic refrigerator device according to any one of claims 1 to 4, 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 the refrigeration layer and the regenerative layer are arranged in an overlapping manner.

6. The magnetic refrigerator device of claim 1, wherein, The refrigeration array comprises 2-100 refrigeration units; the refrigeration layer comprises 2-100 magnetic refrigerant pieces.

7. The magnetic refrigerator device of claim 1, wherein, The refrigeration array comprises 2-25 refrigeration units; the refrigeration layer comprises 4-25 magnetic refrigerant pieces.

8. The magnetic refrigerator device of claim 1, wherein, 12.The single magnetic field operated high efficiency regenerative all-solid-state magnetic refrigeration device of any one of claims 1 to 11 is applied to refrigeration of refrigerators, air conditioners, liquefied gases and microelectronic devices.

9. The magnetic refrigerator device of claim 1, wherein, The application comprises 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, all the magnetic refrigerant pieces are in the magnetic field, and in the other terminal state, all the magnetic refrigerant pieces are outside the magnetic field.

10. The magnetic refrigerator device of claim 9, wherein, The strength of the magnetic field is 0.1-60 T.

11. The magnetic refrigerator device of claim 10, wherein, The strength of the magnetic field is 0.5 T-3 T. The frequency of the reciprocating translational motion of the refrigeration layer and the regenerative layer is the same frequency of 0.01-1000 Hz.

13. Use according to claim 12, wherein, ​ 14. The use according to claim 12, wherein, ​ 15. Use according to claim 14, wherein, ​ 16. The use according to claim 12, wherein, ​ 17. Use according to claim 16, wherein, The frequency of the reciprocating translation of the refrigeration layer and the regenerative layer is the same frequency of 0.1-20 Hz.

18. The use according to any one of claims 12 to 17, wherein, The application comprises matching the magnetic refrigeration device with a cold end requiring refrigeration and a hot end requiring heat dissipation, the cold end and the hot end being located at two movement terminals of the reciprocating translation of the magnetic refrigeration device, and at the two movement terminals, the two outermost magnetic refrigeration working substance pieces of the plurality of magnetic refrigeration working substance pieces respectively exchange heat with the cold end and the hot end, When the cold end is located at the left side and the hot end is located at the right side, the application comprises: taking the right side hot end as the starting point, placing 40%-70% of the area of the reciprocating translation of the magnetic refrigeration device in the magnetic field, and operating according to the following time sequence: (1) the refrigeration layer and the regenerative layer are stationary at the cold end movement terminal, wherein each refrigeration working substance piece respectively exchanges heat with the left side regenerative working substance piece and the cold end, and absorbs heat from the cold end and the left side regenerative working substance piece; (2) the refrigeration layer and the regenerative layer simultaneously move to the hot end and enter the magnetic field, wherein the moving speed of the refrigeration layer is faster than that of the regenerative layer, and the refrigeration working substance piece enters the magnetic field to complete the temperature rising process after leaving the cold end and the left side regenerative working substance piece and before contacting the right side regenerative working substance piece and the hot end; (3) the refrigeration layer and the regenerative layer are stationary at the hot end movement terminal after entering the magnetic field, wherein each refrigeration working substance piece respectively exchanges heat with the right side regenerative piece and the hot end, and releases heat to the hot end and the right side regenerative piece; (4) the refrigeration layer and the regenerative layer simultaneously move to the cold end and leave the magnetic field, wherein the moving speed of the refrigeration layer is faster than that of the regenerative layer, and the refrigeration working substance piece completes the temperature lowering process after leaving the hot end and the right side regenerative piece and before contacting the left side regenerative piece and the cold end; (5) the above operations are reciprocally switched according to the sequence of (1)-(4), so as to transport heat from the cold end to the hot end and realize refrigeration; Alternatively, the application comprises operating according to the following time sequence: the refrigeration layer and the regenerative layer first enter the magnetic field and stop at the movement terminal of (3), and after being cooled to room temperature to complete initialization, the above operations are reciprocally switched according to the sequence of (3)-(4)-(1)-(2), so as to transport heat from the cold end to the hot end and realize refrigeration.

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