Room temperature magnetic refrigeration cycle device

Abstract

The utility model discloses a room temperature magnetic refrigeration cycle device which comprises a magnet set, magnet set driving devices, a double-layer heat regenerator and heat regenerator driving devices, the magnet set driving devices capable of driving the magnet set to reciprocate up and down are symmetrically connected to the two sides of the magnet set, and a high-magnetic-field-intensity air gap is formed in the magnet set. The double-layer heat regenerator is matched with the high-magnetic-field-intensity air gap, and the heat regenerator driving device is arranged on the left side of the double-layer heat regenerator and drives the heat regenerator to reciprocate left and right. According to the room-temperature magnetic refrigeration cycle device, heat exchange fluid is thoroughly removed from the interior of the double-layer heat regenerator, one-way self-heat regeneration independent of additional elements in the double-layer heat regenerator under a reciprocating structure is achieved, meanwhile, stepped distribution of MCM infinitesimal cell temperature between the cold end and the hot end is achieved through the space-time matching design in the double-layer heat regenerator, and the temperature of the MCM infinitesimal cell temperature between the cold end and the hot end is improved. And the refrigerating capacity is effectively improved on the premise of ensuring the temperature span.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to a room temperature magnetic refrigeration cycle device. Background Technology

[0002] Green environmental protection and energy and water conservation have become rigid requirements for the development of my country's air conditioning industry. Currently, the annual output value of my country's refrigeration and air conditioning industry exceeds 600 billion yuan, but mainstream vapor compression refrigeration technology still relies on refrigerants with fluorocarbons (HFCs) as the working fluid. HFCs pose leakage risks in production and use, and their global warming potential (GWP) is generally higher than 1000, contributing significantly to the greenhouse effect. To address this challenge, the Kigali Amendment to the Montreal Protocol, which came into effect in 2019, explicitly requires a reduction in HFC consumption. However, the development of alternative refrigerants faces multiple constraints: fluorocarbons and olefins need to balance flammability, high GWP, and toxicity; natural working fluids (such as ammonia and carbon dioxide) pose safety hazards. Against this backdrop, the development of new climate-friendly refrigeration technologies with zero GWP has become an urgent need.

[0003] Magnetic refrigeration technology, based on the magnetocaloric effect of magnetocaloric materials (MCMs), is considered an important alternative to HFCs due to its zero ground power consumption (GWP), high thermodynamic efficiency, and rapid response characteristics. Common magnetocaloric materials include gallium-based alloys and manganese-based compounds. Currently, room-temperature magnetic refrigerators based on active regenerative (AMR) cycles have entered the engineering stage, but their core drawback stems from their reliance on heat transfer mechanisms using heat exchange fluids.

[0004] (1) Material corrosion and frequency limitation: The fluid medium makes the MCM susceptible to corrosion, and the system operating frequency is limited by the fluid flow rate;

[0005] (2) Insufficient heat transfer efficiency: The complex flow path and non-ideal contact between the fluid and the MCM result in a large heat transfer temperature difference and high irreversible loss;

[0006] (3) Secondary heat exchange bottleneck: The establishment of the temperature span requires a secondary heat exchange process of “MCM→fluid→MCM”, which further aggravates energy dissipation.

[0007] The aforementioned issues indicate that improvements in the energy efficiency of AMR cycles are limited by the convective heat transfer mechanism between the fluid and the MCM. Therefore, all-solid-state magnetic refrigeration technology (replacing the fluid medium with solid-state heat transfer) has become a breakthrough direction. Existing research focuses on solid-state enhanced heat transfer structures (such as thermal switches and phase change materials) and novel cycle designs, but still faces two major bottlenecks:

[0008] (1) Reliance on external thermal control components: The regeneration process needs to be realized by thermoelectric semiconductors or kH heat pipes, which greatly increases the complexity and cost of the system;

[0009] (2) Temperature span limitation: The thermal resistance of the solid heat transfer interface makes it difficult for the actual temperature span to meet the requirements of air conditioning operation (usually >15K). Utility Model Content

[0010] The purpose of this invention is to provide a room temperature magnetic refrigeration cycle device that can completely eliminate the heat exchange fluid inside the regenerator and achieve unidirectional self-heating without relying on external components in the reciprocating structure. At the same time, through the "spatiotemporal matching" design inside the regenerator, a stepped temperature distribution of the MCM micro-cell between the hot and cold ends is achieved, which effectively improves the cooling capacity while ensuring the temperature span.

[0011] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0012] A room temperature magnetic refrigeration cycle device includes a magnet assembly, a magnet assembly drive device, a double-layer regenerator, and a regenerator drive device. The magnet assembly is symmetrically connected to both sides by the magnet assembly drive devices that can drive the magnet assembly to reciprocate up and down. A high magnetic field strength air gap is provided inside the magnet assembly. The double-layer regenerator is matched with the high magnetic field strength air gap. The regenerator drive device is located on the left side of the double-layer regenerator and drives the regenerator to reciprocate left and right.

[0013] Preferably, the magnet assembly is a linear magnet assembly, which includes an upper magnet and a lower magnet arranged symmetrically. The upper magnet and the lower magnet are each composed of five magnetic blocks with different magnetization directions, and the magnetic blocks are spliced ​​together to form a high magnetic field strength air gap.

[0014] Preferably, the double-layer regenerator includes an upper regenerator and a lower regenerator, each containing cells. The cells of the upper regenerator are entirely filled with a magnetocaloric material. A cold-end heat exchanger is placed in the leftmost cell of the lower regenerator, and a hot-end heat exchanger is placed in the rightmost cell. The remaining cells of the lower regenerator are filled with a magnetocaloric material. The left side of the upper regenerator is connected to a regenerator drive device.

[0015] Preferably, the magnetocaloric material is in the form of a rectangular block.

[0016] Preferably, an upper heat insulation sleeve is provided on the outside of the upper heat exchanger, and a lower heat insulation sleeve is provided on the outside of the lower heat exchanger. Both the upper and lower heat insulation sleeves are made of PVC material.

[0017] Preferably, it also includes a support frame, an intermediate heat transfer plate, and a heat transfer block. The intermediate heat transfer plate is disposed above the support frame and between the upper and lower regenerators. The heat transfer block is embedded inside the intermediate heat transfer plate, and the regenerator drive device is disposed above the left side of the intermediate heat transfer plate.

[0018] Preferably, the heat transfer block array arrangement corresponds to the layout of the lower regenerator cell, and the heat transfer block is made of copper.

[0019] Preferably, it also includes a base plate, with the magnet assembly drive device and support frame disposed above the base plate.

[0020] This utility model, by adopting the above-mentioned technical solution, has the following beneficial effects:

[0021] 1. This invention, through its all-solid-state magnetic refrigeration cycle architecture and dynamic gradient arrangement design of magnetocaloric material (MCM), completely eliminates the need for heat exchange fluids, achieving a revolution in heat exchange media. It uses only MCM as the refrigeration and cold storage material, fundamentally solving the three major defects of traditional AMR cycles:

[0022] 1) Eliminate corrosion and frequency bottlenecks: No fluid medium is involved, avoiding the performance degradation of MCM caused by fluid corrosion, and at the same time removing the limitation of flow rate on system operating frequency;

[0023] 2) Optimize the heat transfer path: Directly conduct heat through solid-state contact to eliminate heat transfer efficiency loss caused by disordered fluid molecule movement (experiments show that the interfacial thermal resistance is reduced by about 40%).

[0024] 3) Avoiding secondary heat exchange losses: The establishment of the temperature span depends only on a single heat transfer between MCMs, which reduces the thermodynamic irreversible loss by more than 50% compared to the traditional secondary heat exchange mode of "MCM→heat exchange fluid→MCM".

[0025] 2. This utility model achieves the synergistic benefits of reconstructing the regenerative mechanism by arranging the magnetocaloric materials in layers:

[0026] 1) Spatiotemporal matching of cooling capacity: The cooling phase of the upper MCM is synchronized with the cooling demand of the lower layer in real time, and a spontaneous heat recovery mechanism is constructed. The large temperature difference heat recovery between the fluid and the MCM in the traditional AMR cycle (ΔT>8K) is decomposed into small temperature difference step heat transfer between adjacent MCM units (ΔT<2K).

[0027] 2) Minimize entropy production: Precisely control the temperature gradient distribution of the micro-cell to make the regeneration process approach a quasi-equilibrium state, reducing the total entropy production of the system by more than 30%;

[0028] 3) Improved cooling performance: While maintaining the target temperature range (>15K), the cooling capacity per unit cycle is increased by 15%. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of this utility model;

[0030] Figure 2 A schematic diagram of the magnet assembly and its driving device;

[0031] Figure 3 This is a schematic diagram of the high magnetic field strength air gap inside the magnet assembly;

[0032] Figure 4 A schematic diagram showing the direction of magnetization of a magnet;

[0033] Figure 5 This is a schematic diagram of a double-layer regenerator structure;

[0034] Figure 6 Schematic diagram of the upper regenerator and drive unit;

[0035] Figure 7 Schematic diagram of the filling configuration of the upper regenerator;

[0036] Figure 8 This is a schematic diagram of the lower-level regenerator;

[0037] Figure 9 A schematic diagram of the filling configuration of the lower-level regenerator;

[0038] Figure 10 This is a schematic diagram of the intermediate heat transfer plate.

[0039] In the diagram: 1. Magnet assembly drive device; 2. Upper magnet; 3. Lower magnet; 4. Lower regenerator; 5. Regenerator drive device; 6. Upper regenerator; 7. Support frame; 8. Base plate; 9. High magnetic field strength air gap; 10. Magnetothermal material; 11. Upper insulation jacket; 12. Cold end heat exchanger; 13. Hot end heat exchanger; 14. Lower insulation jacket; 15. Intermediate heat transfer plate; 16. Heat transfer block. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects can be achieved even without these specific details.

[0041] Example 1

[0042] like Figure 1 As shown, a room temperature magnetic refrigeration cycle device includes a magnet assembly, a magnet assembly drive device 1, a double-layer regenerator, and a regenerator drive device 5, as shown. Figure 2 As shown, symmetrical magnet drive devices 1 are connected to both sides of the magnet assembly to drive the magnet assembly to reciprocate up and down. In specific implementations, the magnet drive device is an electric push rod, linear motor, servo motor, or cylinder that can drive the magnet assembly to reciprocate up and down. Figure 1The magnet assembly drive device is an electric push rod, which includes a motor, an output shaft, and a push rod. The output shaft of the motor drives the push rod to reciprocate up and down. The push rod is connected to both ends of the magnet assembly, and the push rod drives the magnet assembly to reciprocate up and down. The magnet assembly is provided with a high magnetic field strength air gap 9. The double-layer regenerator is matched with the high magnetic field strength air gap 9. The regenerator drive device 5 is located on the left side of the double-layer regenerator and drives the regenerator to reciprocate left and right. In specific implementation, the regenerator drive device is a linear motor or servo motor that can drive the regenerator to reciprocate left and right.

[0043] like Figure 3-4 As shown, the magnet group is a linear magnet group, which includes an upper magnet 2 and a lower magnet 3 arranged symmetrically. The upper magnet 2 and the lower magnet 3 are each composed of five magnetic blocks with different magnetization directions. The magnetic blocks are spliced ​​together to form a high magnetic field strength air gap 9.

[0044] like Figure 5-9 As shown, the double-layer regenerator includes an upper regenerator 6 and a lower regenerator 4, each containing internal cells. The cells of the upper regenerator 6 are fully filled with magnetocaloric material 10. In the double-layer regenerator structure, the upper regenerator 6 and the lower regenerator 4 are filled with magnetocaloric material and contain no fluid, thus avoiding the problem of corrosion of the magnetocaloric material. At the same time, it overcomes the limitation of the system's operating frequency, eliminates the problem of large temperature difference regeneration between the fluid and the material, reduces irreversible losses in the cycle, and improves the system efficiency.

[0045] A cold-end heat exchanger 12 is placed in the leftmost cell of the lower regenerator 4, and a hot-end heat exchanger 13 is placed in the rightmost cell of the lower regenerator 4. The remaining cells of the lower regenerator 4 are filled with a magnetothermal material 10, which is commercially available. The left side of the upper regenerator 6 is connected to the regenerator drive device 5. The magnetothermal material 10 is rectangular in shape. An upper heat insulation sleeve 11 is provided on the outside of the upper regenerator 6, and a lower heat insulation sleeve 14 is provided on the outside of the lower regenerator 4. Both the upper heat insulation sleeve 11 and the lower heat insulation sleeve 14 are made of PVC material. PVC material has a low thermal conductivity and can block heat transfer between magnetothermal materials 10 in the same layer.

[0046] This invention achieves a four-step cyclic process through the up-and-down movement of the magnet assembly and the left-and-right movement of the upper regenerator 6, including magnetization, demagnetization, heat transfer, and heat exchange. It realizes unidirectional self-heating within the regenerator without relying on external components; decomposes large temperature difference regeneration into small temperature difference regeneration between material blocks, achieving precise regeneration; forms a stepped temperature distribution of the MCM micro-cell between the hot and cold ends, increasing cooling capacity; effectively reduces cycle entropy production, and improves system efficiency.

[0047] When the upper regenerator 6 is in a magnetized state and the lower regenerator 4 is in a demagnetized state, the electric push rod extends to the right, bringing the rightmost magnetocaloric material 10 of the upper regenerator 6 into contact with the rightmost hot-end heat exchanger 13 of the lower regenerator 4 for heat dissipation. The remaining magnetocaloric material 10 in the upper regenerator 6 transfers heat to the magnetocaloric material 10 in the lower regenerator 4. When the lower regenerator 4 is in a magnetized state and the upper regenerator 6 is in a demagnetized state, the regenerator drive device 5 is activated, driving the electric push rod to shorten to the left, bringing the leftmost magnetocaloric material 10 of the upper regenerator 6 into contact with the leftmost cold-end heat exchanger 12 of the lower regenerator 4 for cooling. The remaining magnetocaloric material 10 absorbs the heat gained by the magnetocaloric material 10 in the lower regenerator 4 due to magnetization. By coordinating the movement of the magnet assembly with the movement of the regenerator, precise control of magnetization, demagnetization, and heat transfer is achieved. The spatiotemporal matching of cooling generation and cooling consumption improves the thermodynamic efficiency of the system; avoids the secondary heat exchange process of "magnetothermal material-heat exchange fluid-magnetothermal material" in the traditional AMR cycle; and also reduces irreversible losses in the heat exchange process, thereby improving the overall performance of the system.

[0048] Example 2

[0049] As shown in the figure, this embodiment is consistent with Embodiment 1 in other structures and performance parameters, except that it also includes a support frame 7, an intermediate heat transfer plate 15, and a heat transfer block 16, as follows. Figure 10 As shown, the intermediate heat transfer plate 15 is positioned above the support frame 7 and is located between the upper regenerator 6 and the lower regenerator 4. The heat transfer blocks 16 are embedded inside the intermediate heat transfer plate 15, and the regenerator drive device 5 is positioned above the left side of the intermediate heat transfer plate 15. The heat transfer blocks 16 are made of copper, and their array arrangement corresponds to the cell layout of the lower regenerator 4 to reduce the thermal resistance between the upper and lower regenerators 4. The number of heat transfer blocks 16 is consistent with the number of cells in the lower regenerator 4. The system also includes a base plate 8, with the magnet assembly drive device 1 and the support frame 7 positioned above the base plate 8.

[0050] The working principle of this room temperature magnetic refrigeration cycle device is as follows:

[0051] Start the magnet assembly drive device 1 to move the entire magnet assembly downwards, so that the upper regenerator 6 moves into the interior of the upper magnet 2 and the upper regenerator 6 is magnetized; at the same time, the lower regenerator 4 moves out of the interior of the lower magnet 3 and the lower regenerator 4 is demagnetized.

[0052] The position of the magnet assembly remains unchanged. The magnetocaloric material 10 in the upper regenerator 6 heats up due to magnetization and transfers heat to the magnetocaloric material 10 in the lower regenerator 4, which cools down due to demagnetization. At the same time, the magnetocaloric material 10 on the far right of the upper regenerator 6 transfers heat to the hot-end heat exchanger 13 for heat dissipation.

[0053] Start the magnet assembly drive device 1 to move the entire magnet assembly upward, so that the upper regenerator 6 moves out of the upper magnet 2 and is demagnetized, while the lower regenerator 4 moves into the lower magnet 3 and is magnetized; at the same time, start the regenerator drive device 5 to move the entire upper regenerator 6 to the left, so that the leftmost magnetothermal material 10 comes into contact with the cold end heat exchanger 12.

[0054] The position of the magnet assembly remains unchanged, but the direction of heat transfer is opposite to that in step (2). The magnetocaloric material 10 located in the lower regenerator 4 heats up due to magnetization and transfers heat to the magnetocaloric material 10 located in the upper regenerator 6, which cools down due to demagnetization. At the same time, the magnetocaloric material 10 located on the far left of the upper regenerator 6 comes into contact with the hot end heat exchanger 13 to absorb heat and cool down.

[0055] This novel room-temperature magnetic refrigeration cycle device achieves a four-step cycle process through the reciprocating motion of the magnet assembly and the left-right reciprocating motion of the upper regenerator 6, including magnetization, demagnetization, heat transfer, and heat exchange. This invention completely eliminates the need for heat exchange fluids, adopts an all-solid-state design, and achieves unidirectional self-heating within the double-layer regenerator in a reciprocating structure without relying on external components. Simultaneously, through the "spatiotemporal matching" design within the double-layer regenerator, it achieves a stepped temperature distribution in the MCM micro-cells between the hot and cold ends, effectively increasing the cooling capacity while ensuring temperature range.

[0056] This invention, through its innovative structural design and working principle, effectively overcomes the problems of magnetocaloric material corrosion caused by heat exchange fluid, limited system operating frequency, and low heat exchange efficiency in traditional AMR cycles. By arranging magnetocaloric materials in a layered manner, it achieves a precise heat recovery cycle design, effectively reducing cycle entropy production. It also realizes a stepped temperature distribution of the MCM micro-cell between the hot and cold ends, improving the cooling capacity while ensuring the temperature span. This provides new ideas and possibilities for the practical application of room temperature magnetic refrigeration technology.

[0057] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A room temperature magnetic refrigeration cycle device, characterized in that: It includes a magnet assembly, a magnet assembly drive device, a double-layer regenerator, and a regenerator drive device. The magnet assembly is symmetrically connected to both sides by magnet assembly drive devices that can drive the magnet assembly to reciprocate up and down. A high magnetic field strength air gap is provided inside the magnet assembly. The double-layer regenerator is matched with the high magnetic field strength air gap. The regenerator drive device is located on the left side of the double-layer regenerator and drives the regenerator to reciprocate left and right.

2. The room temperature magnetic refrigeration cycle device according to claim 1, characterized in that: The magnet assembly is a linear magnet assembly, which includes an upper magnet and a lower magnet arranged symmetrically. The upper magnet and the lower magnet are each composed of five magnetic blocks with different magnetization directions. The magnetic blocks are spliced ​​together to form a high magnetic field strength air gap.

3. The room temperature magnetic refrigeration cycle device according to claim 1 or 2, characterized in that: The double-layer regenerator includes an upper regenerator and a lower regenerator, each containing cells. The cells of the upper regenerator are entirely filled with a magnetothermal material. A cold-end heat exchanger is placed in the leftmost cell of the lower regenerator, and a hot-end heat exchanger is placed in the rightmost cell. The remaining cells of the lower regenerator are filled with a magnetothermal material. The left side of the upper regenerator is connected to a regenerator drive device.

4. The room temperature magnetic refrigeration cycle device according to claim 3, characterized in that: The magnetocaloric material is in the form of a rectangular block.

5. The room temperature magnetic refrigeration cycle device according to claim 3, characterized in that: An upper heat insulation sleeve is provided on the outside of the upper regenerator, and a lower heat insulation sleeve is provided on the outside of the lower regenerator.

6. The room temperature magnetic refrigeration cycle device according to claim 3, characterized in that: It also includes a support frame, an intermediate heat transfer plate and a heat transfer block. The intermediate heat transfer plate is located above the support frame and between the upper and lower regenerators. The heat transfer block is embedded inside the intermediate heat transfer plate. The regenerator drive device is located on the upper left side of the intermediate heat transfer plate.

7. The room temperature magnetic refrigeration cycle device according to claim 6, characterized in that: The arrangement of the heat transfer block array corresponds to the layout of the lower-level regenerator cells.

8. The room temperature magnetic refrigeration cycle device according to claim 6, characterized in that: It also includes a base plate, and the magnet assembly drive device and support frame are disposed above the base plate.

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