Active cooling structure, Stirling cryocooler and refrigerating system

Abstract

The invention relates to the technical field of Stirling refrigeration, and discloses an active cooling structure, a Stirling cryocooler and a refrigeration system.The active cooling structure comprises a cooling medium source, a heat exchange body and a driving device, the heat exchange body is provided with an input end and an output end, a flow channel is formed in the heat exchange body, and the heat exchange body is attached to the outer wall of the hot end of the Stirling cryocooler; the driving device is used for actively conveying the cooling medium into the flow channel, forced convection heat exchange between the cooling medium and the hot end is achieved, and therefore the temperature of the hot end is reduced, and the refrigeration limit performance of the cold end is improved. The Stirling cryocooler based on the structure has better thermal stability and low-temperature output capacity. Furthermore, the invention further provides a refrigerating system, the temperature of the hot end of the Stirling cryocooler is reduced through the first refrigerating module, then the lower refrigerating temperature is achieved, and the refrigerating system is suitable for various application scenes.

Description

Technical Field

[0001] This application relates to the field of Stirling refrigeration technology, and further to an active cooling structure, a Stirling refrigerator, and a refrigeration system. Background Technology

[0002] In existing Stirling refrigerators, the hot end typically uses natural heat dissipation or structural heat exchange for cooling. However, under low-temperature conditions or high loads, the heat dissipation capacity of the hot end is often insufficient. Since the hot end continuously bears the exothermic effect of the compressed working fluid, if the heat cannot be dissipated in a timely and effective manner, the temperature of the hot end will rise, leading to a decrease in regenerative efficiency. This can even have a reverse effect on the heat exchange state of the cold end, making it difficult to further reduce the cooling temperature of the cold end, ultimately limiting the overall cooling performance of the system. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this application is to provide an active cooling structure, a Stirling refrigerator, and a refrigeration system that can effectively maintain the low-temperature stability of the hot end and improve the cooling efficiency and system stability of the entire Stirling cycle.

[0004] To achieve the above objectives, this application provides an active cooling structure, comprising:

[0005] Cooling medium source;

[0006] A heat exchanger body has at least one input end and at least one output end; it has a flow channel inside, and both the input end and the output end are connected to the flow channel. The heat exchanger body is at least partially attached to the outer wall of the hot end of the Stirling refrigerator so that the cooling medium can flow through the flow channel across the surface of the hot end of the Stirling refrigerator.

[0007] A driving device is connected to a cooling medium source and a heat exchanger body. It is used to actively deliver cooling medium to the flow channel, so that the hot end of the Stirling refrigerator and the heat exchanger body can perform forced convection heat exchange, thereby reducing the cooling temperature limit of the cold end of the Stirling refrigerator.

[0008] In some embodiments, the heat exchanger body includes a main body and a shell disposed outside the main body, with the flow channel defined between the outer side of the main body and the inner side of the shell. The input end and the output end are both disposed in the shell. When the cooling medium flows through the flow channel, the cooling medium flows along at least a portion of the contour trajectory of the main body.

[0009] In some embodiments, the heat exchange body further includes at least one partition portion, which is arranged in an annular, quasi-annular, or arc-shaped profile along the circumference of the body portion, and the partition portion is fixed to the side wall of the body portion near the shell in a vertical or inclined manner, so that the flow channel is divided into at least two branch channels by the partition portion; in the working state, the cooling medium input to the heat exchange body can flow along the multiple branch channels.

[0010] In some embodiments, the number of partitions is greater than or equal to two, and each pair of adjacent partitions together form a branch channel; and the partitions are arranged at preset intervals along the thickness direction of the main body, the preset intervals corresponding to the width of the corresponding branch channel;

[0011] And / or, the partitions are all made of thermally conductive materials, so as to form, together with the main body, the heat exchange structure between the active cooling structure and the hot end of the Stirling refrigerator.

[0012] In some embodiments, the main body portion has a recessed portion at a position corresponding to the input terminal;

[0013] The recessed portion is connected to the flow channel and is used to guide the cooling medium to be pre-distributed or have its flow rate buffered before entering the flow channel.

[0014] In some embodiments, a flow divider baffle is provided in the recess to divide the cooling medium so that the cooling medium is distributed to at least two branches of the flow channel.

[0015] In some embodiments, the number of input terminals and the number of output terminals are both one, and the input terminals and the output terminals are respectively disposed at relative radial positions of the heat exchange body and are symmetrically arranged along the diameter direction of the heat exchange body.

[0016] In some embodiments, the heat exchanger body is a sleeve-shaped structure, and the inner peripheral wall of the heat exchanger body is fitted to the outer wall of the hot end of the Stirling refrigerator.

[0017] Another aspect of this application also provides a Stirling refrigerator, comprising:

[0018] The cold end is used to absorb external heat to achieve a cooling effect.

[0019] The hot end is thermally connected to the cold end and is used to release heat to the outside.

[0020] The compression chamber and expansion chamber are used to compress and expand the working medium, respectively. The hot end is thermally coupled to the compression chamber, and the cold end is thermally coupled to the expansion chamber, thereby forming a closed thermodynamic working circuit in the Stirling refrigerator.

[0021] A regenerator, located between the cold end and the hot end, is used to recover and reuse heat from the reciprocating working medium.

[0022] The active cooling structure in any of the above embodiments is disposed at the hot end and is used to actively cool the hot end.

[0023] Another aspect of this application also provides a refrigeration system, comprising:

[0024] The first refrigeration module has a cold end, which is used to output cooling capacity;

[0025] The second refrigeration module adopts the Stirling refrigerator as described in the previous embodiment, and the hot end of the Stirling refrigerator is provided with an active cooling structure.

[0026] The intermediate heat exchange module thermally couples the cold end of the first refrigeration module and the active cooling structure of the second refrigeration module, so that the first refrigeration module and the second refrigeration module form a composite refrigeration system. The first refrigeration module continuously or intermittently reduces the hot end temperature of the Stirling refrigerator to achieve a lower refrigeration temperature.

[0027] Compared with the prior art, the active cooling structure, Stirling refrigerator, and refrigeration system provided in this application have at least the following beneficial effects:

[0028] The heat exchanger body has internal channels for the cooling medium, and in conjunction with a drive device, the cooling medium is actively transported to the heat exchange area at the hot end of the Stirling refrigerator, achieving forced convection heat transfer between the hot end and the medium within the channels. Compared to passive cooling methods, this structure can quickly remove heat accumulated at the hot end, improving the heat dissipation efficiency at the hot end and thus significantly reducing the minimum cooling temperature at the cold end of the Stirling refrigerator. Attached Figure Description

[0029] The preferred embodiments will now be described in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of this application.

[0030] Figure 1 This is a schematic diagram of the active cooling structure applied to a Stirling refrigerator in one embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the active cooling structure in one embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the main body in one embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the structure of a refrigeration system in one embodiment of this application.

[0034] Reference numerals: 1. Active cooling structure; 10. Heat exchanger body; 100. Flow channel; 101. Input end; 102. Output end; 11. Main body; 12. Shell; 13. Partition; 130. Branch channel; 14. Recess; 15. Diverter baffle; 21. Cold end; 22. Hot end; 23. Compression chamber; 24. Expansion chamber; 25. Regenerator; 26. Linear motor; 27. Power piston; 28. Gas distribution piston; 29. ​​Vibration absorber; 31. First refrigeration module; 32. Second refrigeration module; 33. Intermediate heat exchange module. Detailed Implementation

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0036] To keep the drawings concise, each drawing only schematically shows the parts relevant to the application; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one."

[0037] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Existing Stirling refrigerators generally employ natural convection, metal radiation, or passive cooling structures to dissipate heat at the hot end. While these structures can maintain a certain thermal balance in conventional temperature ranges, they are prone to localized heat accumulation at the hot end due to the continuous absorption of large amounts of heat released by the compressed gas in applications such as deep cryogenics, continuous operation, or rapid start-up.

[0041] When the hot-end temperature cannot be effectively controlled, several cascading problems will occur: First, the temperature difference between the hot end and the regenerator decreases, reducing regeneration efficiency; second, the thermal pathway for reverse heat transfer from the hot end to the cold end strengthens, leading to a decrease in the cold-end cooling capacity; finally, the overall thermodynamic efficiency of the system decreases, making it difficult to maintain the cold-end temperature at extremely low levels, and even causing temperature fluctuations, affecting the stable operation of the equipment. Therefore, whether the heat dissipation capacity of the hot end is sufficient directly determines whether the cold end has the potential to break through the cooling limit temperature, and is one of the core bottlenecks affecting the performance of Stirling refrigerators.

[0042] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0043] In one embodiment, refer to the appendix to the specification. Figure 1 The present application describes an active cooling structure that can establish a controllable cooling loop and achieve active heat exchange in the hot end region 22 of the Stirling refrigerator, thereby effectively improving the thermal management capability of the Stirling refrigeration system.

[0044] Reference manual attached Figures 1 to 3 The present application provides an active cooling structure for cooling the hot end 22 of a Stirling refrigerator. The structure mainly includes a cooling medium source, a heat exchange body 10 and a driving device. The cooling medium source is used to provide a cooling medium, which can be a liquid or gaseous medium, and is supplied to the heat exchange body 10 through an external storage tank, a cooling unit or other constant temperature equipment.

[0045] Importantly, the heat exchanger body 10, as the direct structure for cooling the hot end 22, has an internal flow channel 100 for the flow of the cooling medium, and at least part of the outer surface of the heat exchanger body 10 is arranged in close contact with the outer wall of the hot end 22 of the Stirling refrigerator. The heat exchanger body 10 has at least one input end 101 and at least one output end 102, which are respectively connected to the flow channel 100, thereby forming a complete cooling path.

[0046] During operation, the cooling medium flows in from the inlet 101, flows through the internal flow channel 100 within the heat exchange body 10, and then approaches the surface area of ​​the hot end 22 for heat exchange. Finally, it flows out from the outlet 102, completing one cooling cycle. This structure ensures that the cooling medium has a clear flow path within the heat exchange body 10 and forms a stable heat conduction interface with the surface of the hot end 22, thereby guaranteeing efficiency and directionality during the heat exchange process.

[0047] The drive device is located between the cooling medium source and the heat exchange body 10. It is used to transport the cooling medium from the cooling medium source to the interior of the heat exchange body 10 and maintain the continuous flow of the medium in the heat exchange path. Generally, a common pump-type fluid transfer mechanism can be used.

[0048] Understandably, the active driving action of this drive device enables the cooling medium to form a continuous flow within the closed channel, enhancing the heat exchange efficiency between it and the hot end 22. During the operation of the Stirling refrigerator, the hot end 22 continuously absorbs heat from the high-temperature working fluid in the compression chamber 23. If this heat is not released in time, it will cause the temperature of the hot end 22 to rise, thereby affecting the maintenance of the temperature difference at the cold end 21 and reducing the depth of cooling.

[0049] In this embodiment, the cooling medium that is actively driven to circulate can quickly and effectively remove the heat accumulated at the hot end 22, maintain the temperature of the hot end 22 at a relatively stable low level, and provide good thermal field conditions for the cold end 21 to maintain a low temperature.

[0050] It should be noted that the spatial arrangement of the input terminal 101 and the output terminal 102 in this embodiment can be optimized and adjusted according to the overall configuration of the structure to adapt to the space and fluid requirements in different refrigeration application scenarios.

[0051] Based on the above, optionally, in one implementation, the heat exchanger body 10 can be designed as a split structure to facilitate the external integration of the active cooling function of the hot end 22 without altering the existing Stirling refrigerator body structure. Specifically, the heat exchanger body 10 can be composed of two or more split components. These components, in their assembled state, can be arranged around the outer periphery of the hot end 22 of the Stirling refrigerator, forming a closed, fitted structure, thereby achieving a circumferential, fixed coverage of the outer wall of the hot end 22. The connection method for each split component can be bolt connection, clamp connection, positioning slot insertion, or other detachable fixing structures to facilitate subsequent installation, replacement, or maintenance operations.

[0052] Each component can be equipped with at least one fluid channel, which is connected to the corresponding input end 101 and output end 102 respectively. This allows the split heat exchanger body 10 to not only have good on-site installation convenience and structural compatibility, but also to achieve a tight thermal coupling relationship with the hot end 22 without interfering with the structure of the original refrigeration system core components.

[0053] This split-type setup is particularly suitable for existing or in-use Stirling chiller systems. By installing the heat exchanger body 10 later, the active cooling function can be quickly integrated into the original system, significantly improving system operating efficiency and cooling capacity. At the same time, it avoids structural modifications to the main unit, further expanding the applicability of the active cooling structure 1 at the hot end 22. It provides an effective structural implementation path for the universal active cooling retrofit of various types of Stirling chillers.

[0054] In one embodiment, based on the content of the above embodiments, such as Figure 2 As shown, the heat exchange body 10 includes a main body 11 and a shell 12 disposed outside the main body 11. The main body 11 is a structure that fits into the outer wall of the hot end 22 of the Stirling refrigerator and has a contour structure formed along the outer surface of the hot end 22. The shell 12 is disposed outside the main body 11.

[0055] The main body 11 and the housing 12 are arranged opposite to each other, forming an annular or near-annular intermediate cavity between them. This intermediate cavity constitutes a flow channel 100 for the flow of cooling medium. Specifically, the flow channel 100 is defined between the outer surface of the main body 11 and the inner surface of the housing 12, and is arranged around the outer contour of the main body 11, thereby achieving a spatial structure of enveloping / surrounding cooling of the hot end 22 of the Stirling refrigerator. Referring to the accompanying drawings, the input end 101 and the output end 102 are respectively provided on the housing 12 and are both connected to the flow channel 100. After the cooling medium enters from the input end 101, it flows along the flow channel 100 between the housing 12 and the main body 11, and finally exits from the output end 102.

[0056] In the actual heat exchange process, the cooling medium will flow in an annular or near-annular manner along at least part of the outer contour of the main body 11 within the closed channel enclosed by the shell 12 and the main body 11. This ensures that the cooling medium is always close to the outer wall of the hot end 22 of the Stirling refrigerator in the flow path, forming a highly efficient and stable forced heat exchange interface. This not only ensures the integrity of the cooling path but also increases the thermal coupling area. Furthermore, the shape of the main body 11 can be adjusted according to the specific contour of the hot end 22.

[0057] Understandably, in this embodiment, by placing the flow channel 100 in the interlayer space between the main body 11 and the shell 12, both the uniform distribution of the heat exchange fluid in the circumferential region of the hot end 22 is ensured, and the flow channel 100 is avoided from causing structural interference to the hot end 22 body. At the same time, placing the input end 101 and the output end 102 together on the outside of the shell 12 helps to realize the modular arrangement of the cooling pipes and the assembly and production process of the structure.

[0058] Furthermore, the flow channel 100 can be arranged continuously around the main body 11 in a spatial structure, or it can be combined with the distribution of heat intensity at the hot end 22 to form a partitioned or variable cross-section structure in local areas to control the flow rate distribution of the cooling medium. For example, the flow channel 100 section corresponding to the high heat flux density region of the hot end 22 can be locally widened or the flow resistance reduced to enhance the residence time of the cooling medium in the region and increase the contact area, while in other regions a constant cross-section or slow flow design is adopted, thereby achieving on-demand cooling and overall balance.

[0059] In one embodiment, the heat exchange body 10 is a sleeve-shaped structure that extends along the axial direction and forms a hollow structure, which can cover the outer peripheral area of ​​the hot end 22 from the outside, so as to realize the continuous fit arrangement of the heat exchange body 10 and the hot end 22 in the circumferential direction.

[0060] Specifically, the inner peripheral wall of the heat exchange body 10 and the outer wall of the hot end 22 are thermally bonded together. The bonding structure can be achieved by direct bonding or by setting a thermally conductive pad or a highly thermally conductive colloid material on the contact surface between the two, so that the heat exchange body 10 can be tightly attached to the surface of the hot end 22 to form an efficient heat transfer path and ensure the continuity of the heat exchange process and the heat transfer rate.

[0061] Based on the above embodiments, in some cases, the sleeve-shaped heat exchange body 10 in this embodiment includes an inner layer structure and an outer layer structure, that is, it includes a main body 11 located on the inner side and a shell 12 disposed on the outer side of the main body 11, and an annular interlayer space is formed between the two, thereby forming a flow channel 100 for the cooling medium.

[0062] Understandably, the main body 11, as the inner layer of the sleeve-like structure, has its inner surface attached to the outer wall of the hot end 22 of the Stirling refrigerator, forming the main heat exchange path; the shell 12, as the outer layer structure, has a gap between its inner surface and the main body 11, and is connected to the input end 101 and the output end 102 respectively, thus forming a complete cooling circuit. After the cooling medium flows into the sandwich-type flow channel 100, it will be guided to flow along the outer contour of the main body 11 to exchange heat and cool the hot end 22 of the Stirling refrigerator.

[0063] This embodiment maximizes heat dissipation through the sleeve structure's enveloping design; and the housing 12 and the main body 11 can be sealed by brazing or similar connection methods to achieve the sealing and guiding of the cooling passage through a double-layer structure.

[0064] In one embodiment, the heat exchange body 10 further includes at least one partition 13 for structurally separating the internal flow channels 100, thereby optimizing the flow path of the cooling medium and improving the overall heat exchange efficiency, and avoiding the problem of stagnation of the cooling medium in a large cross-sectional space.

[0065] The partition portion 13 extends circumferentially along the main body portion 11, forming an annular, quasi-annular, or arc-shaped contour structure, and is fixed vertically or inclined to the side wall of the main body portion 11 near the housing 12. The partition portion 13 can be a single piece or a multi-piece structure, which, after installation or molding, spans the internal space of the flow channel 100 in a radial or near-radial direction, so that the flow channel 100, which originally surrounds the outer surface of the main body portion 11, is locally physically divided into two or more interconnected but defined branch channels 130.

[0066] In actual operation, after the cooling medium from the input end 101 enters the heat exchange body 10, it can be diverted and guided along multiple branch channels 130 defined by the partition 13 in the flow channel 100. Different fluid branches can re-merge at the tail of the partition 13 or the end of the path, thereby achieving synchronous coverage and heat exchange of multiple areas on the surface of the hot end 22.

[0067] In addition, the partition 13 is preferably made of a material with good thermal conductivity, such as a metal heat sink, a high thermal conductivity alloy sheet or a surface-treated metal foil, etc. In some cases, its structure can refer to the finned form commonly used in heat sinks.

[0068] By integrating this type of partition 13 into the flow channel 100, it not only serves to divert the flow but also enables it to form a heat exchange structure between the active cooling structure 1 and the hot end 22 of the Stirling refrigerator together with the main body 11. During the process of the cooling medium entering the heat exchange body 10 from the input end 101 and flowing along the internal flow channel 100, the cooling medium will have a heat transfer effect with the surface of the partition 13. Since the thermal path between the partition 13 and the main body 11 is continuous and the partition 13 itself has thermal conductivity, the cooling capacity of the cooling medium can be further conducted to the main body 11 through the partition 13, thereby improving the heat exchange efficiency between the main body 11 and the hot end 22.

[0069] In one embodiment, based on the above embodiments, please refer to the appendix to the specification. Figure 3 The number of partition portions 13 is greater than or equal to two, and they are arranged in a manner along the thickness direction of the main body portion 11. That is, multiple partition portions 13 extend outward from the side wall of the main body portion 11 facing the housing 12, and are spaced apart from each other in the thickness direction at a predetermined interval.

[0070] A branch channel 130 is defined between every two adjacent partitions 13, thereby further dividing the entire flow channel 100 between the housing 12 and the main body 11 into multiple parallel channel structures with equal or unequal spacing. The preset interval can be designed according to the cooling requirements, thereby determining the effective width of each branch channel 130, so that after the cooling medium enters the heat exchange body 10, it can be naturally diverted into multiple channels to flow synchronously, and complete the heat exchange process with the surface of the hot end 22 during the process of passing through each channel.

[0071] Understandably, by setting the partition 13 at a preset interval along the thickness direction, it is possible not only to effectively organize the flow path of the cooling medium and enhance the spatial distribution uniformity of the cooling process, but also to structurally avoid uneven flow velocity and stagnation caused by excessively large local cross-sections during the flow of the medium.

[0072] Compared to the form without multiple partitions 13, this structure significantly increases the total heat exchange area of ​​the cooling medium per unit time by constructing multiple parallel flow channels within a limited interlayer space, thereby achieving a high-throughput, low-temperature-difference forced convection heat exchange effect while ensuring controllable flow resistance.

[0073] Meanwhile, multiple branch channels 130 can be set around the hot end 22 in different directions, making the heat exchange capacity of the hot end 22 more balanced in all directions, reducing the temperature rise fluctuation of the hot end 22 caused by local heat accumulation, further optimizing the spatial flow and heat transfer path design of the cooling medium in the heat exchange body 10, and providing strong support for the stable operation of the Stirling refrigerator hot end 22 under high heat load.

[0074] Of course, based on the above embodiments, some partitions 13 may also be provided with a flow guiding structure, with the front end of the flow guiding structure facing the flow direction of the cooling medium, forming a flow guiding effect, thereby enabling the cooling medium to preferentially flow into a specific branch channel 130.

[0075] In another embodiment, the partition 13 is provided with multiple slits to form a partially connected channel between two adjacent branch channels 130. Specifically, the slits can be gaps, notches, or through-holes in the partition 13, allowing the branch channels 130 originally defined by two adjacent partitions 13 to be interconnected in a local area. During the normal flow of the cooling medium along the branch channels 130, when the fluid flows to the corresponding position of the slit, it can partially enter the adjacent channel, achieving cross-channel disturbance and mixing, thereby forming a rotating turbulent flow or a cross-channel vortex structure within the channel, further enhancing the local heat transfer intensity of the surface area of ​​the hot end 22.

[0076] The location and size of the vacant sections can be designed according to the length of the branch channel 130. They can be located near the input end 101, in the middle, or at the output end 102, or multiple sets can be staggered to create cross-flow disturbance and redistribution of the cooling medium at multiple locations. This prevents the overall cooling path from being a unidirectional linear flow, instead guiding some of the cooling medium to transition laterally between adjacent channels while ensuring the stability of the main flow direction. This swirling effect of the lateral transition allows for more dynamic compensation of the cooling effect in each area, adapting to local temperature rise changes and non-uniform heat load distribution at the hot end 22.

[0077] In one embodiment, the heat exchange body 10 has a recess 14 at the position corresponding to the input end 101. (See attached specification.) Figure 2 and Figure 3 In some cases, the recess 14 is a groove-shaped space structure provided on the side of the main body 11 facing the input end 101, which is connected to the flow channel 100 in the heat exchange body 10 and forms the first contact area before the cooling medium enters the flow channel 100 from the input end 101.

[0078] Understandably, the recess 14 forms a local buffer area in its structure, so that when the cooling medium flows in at high speed from the input pipe, it first forms a preliminary buffer inside the recess 14 to avoid directly impacting the main passage, thereby achieving flow rate transition control at the inlet.

[0079] In other words, by providing a recess 14 on the inlet side of the heat exchanger body 10, the cooling medium can be pre-distributed in the recess 14 before entering the flow channel 100, so that its speed, pressure and flow direction entering the flow channel 100 can be adjusted to a certain extent, which helps the cooling medium to flow evenly in each branch channel 130.

[0080] Meanwhile, the recessed portion 14 can also serve as a guide component when the cooling medium is input. In terms of structural form, it can incorporate certain rounded transitions, streamlined contours, and other designs to guide the cooling medium into the internal fluid cavity in a predetermined direction, thereby improving overall flow efficiency and avoiding the formation of local dead zones. For the flow channel 100 with multiple branch channels 130, the pre-distribution space formed by the recessed portion 14 can achieve initial pressure distribution and guidance before the cooling medium is divided, improving the system's coordination.

[0081] Based on the above, a flow-diverting baffle 15 is further provided inside the recess 14 to directionally divert the cooling medium before it enters the heat exchange body 10, so as to optimize the initial distribution state of the cooling medium in the flow channel 100.

[0082] Referring to the accompanying drawings, the flow divider 15 is located in the internal space of the recess 14, dividing the recess 14 into left and right regions along the circumferential direction of the main body 11. This allows the cooling medium entering the recess 14 to enter the flow channels 100 of the left and right regions respectively on both sides of the flow divider 15 according to its momentum direction and the guidance of the flow divider 15, forming a symmetrical or nearly symmetrical dual-channel parallel flow state.

[0083] Specifically, the flow divider 15 can be a sheet-like structure and fixed to the bottom of the recess 14. In some cases, the baffle body can be made of a thermally conductive metal material to balance structural strength and thermal conductivity. By placing the flow divider 15 on the inflow path of the cooling medium, not only is the spatial separation of the fluid achieved, but it also provides a synergistic effect of flow regulation and flow direction guidance, enabling the cooling medium to achieve preliminary homogenization and symmetrical distribution before entering the flow channel 100.

[0084] In actual operation, the flow divider baffle 15 forms a transitional guiding structure between the recess 14 and the flow channel 100, which can significantly reduce the impact disturbance generated when the cooling medium enters and avoid non-ideal flow states such as flow deviation and flow around the inlet section. Especially in the multi-channel structure with symmetrical left and right arrangement, the flow divider baffle 15 can effectively improve the flow uniformity of the cooling medium in the two branch channels 130, so that the heat exchange area can be fully utilized, improve the overall heat exchange efficiency, and reduce the problem of uneven temperature rise caused by local flow velocity differences.

[0085] In one embodiment, such as Figure 2As shown, there is one input end 101 and one output end 102, which are respectively located at opposite radial positions of the heat exchange body 10 and are symmetrically arranged along the diameter of the heat exchange body 10. Specifically, the input end 101 and the output end 102 are spatially located on the outer shell 12 of the heat exchange body 10, and the line connecting them passes through the geometric center of the heat exchange body 10, so that they form a complete radial axis. This allows the cooling medium to diffuse along both sides of this axis in the circumferential direction of the heat exchange body 10 after entering, and finally be discharged from the output end 102 on the opposite side.

[0086] In general, during operation, after the cooling medium is introduced through the inlet 101, it flows circumferentially to the left and right along the heat exchange body 10, centered on the diameter axis. It passes through the interlayer flow channel formed between the outer side of the main body 11 and the inner side of the shell 12, and after completing its circumferential flow around the entire hot end 22, it flows out from the outlet 102 on the opposite side. Because the inlet 101 and outlet 102 are symmetrically arranged in the radial direction, the cooling medium is naturally guided into a left-right split, symmetrically circumferential path, enabling approximately uniform fluid coverage on the outer surface of the hot end 22 during cooling. This avoids problems such as localized flow concentration, stagnation, or heat exchange dead zones that may occur due to asymmetrical inlet and outlet arrangements.

[0087] In this embodiment, the active cooling structure 1 can achieve a complete cooling path through only a single input terminal 101 and a single output terminal 102, which not only simplifies the pipeline layout and interface control, but also makes the overall structure more compact and more modular.

[0088] In one embodiment, refer to the appendix to the specification. Figure 1 According to another aspect of this application, this application further provides a Stirling refrigerator, mainly including basic components such as a cold end 21, a hot end 22, a compression chamber 23, an expansion chamber 24, and a regenerator 25, and also including the active cooling structure 1 in the above embodiments. The cold end 21 is used to absorb external heat to achieve cooling output. The cold end 21 is thermally coupled to the expansion chamber 24. The working medium in the expansion chamber 24 absorbs heat and undergoes volume expansion at a low temperature, driving the system to complete a reciprocating cycle. The hot end 22 is thermally coupled to the compression chamber 23, allowing the heat released by the high-temperature, high-pressure working medium to be output to the external environment via the hot end 22, thereby completing a closed thermodynamic loop for the working medium.

[0089] The regenerator 25 is located between the cold end 21 and the hot end 22 to recover and reuse heat from the reciprocating working medium, thereby improving cycle efficiency and reducing the system's dependence on external power supply. During the operation of the Stirling refrigerator, the compression chamber 23 and the expansion chamber 24 act on the working medium in different temperature zones, and the temperature difference between the cold end 21 and the hot end 22 forms the driving condition. In this thermodynamic cycle, the hot end 22, as the high-temperature side of the system, directly affects the minimum refrigeration temperature that the cold end 21 can reach.

[0090] In this embodiment, the active cooling structure 1 is set in the outer region of the hot end 22. Through the thermal contact between the heat exchange body 10 and the hot end 22, the cooling medium achieves forced convection heat exchange to the hot end 22, thereby quickly removing the accumulated heat of the hot end 22 and avoiding the problem of the temperature rising too fast due to continuous compression and heat release. This keeps the temperature of the hot end 22 at a relatively low level and operates stably, thereby optimizing the low-temperature output capability of the cold end 21.

[0091] Understandably, the Stirling refrigerator provided in this embodiment organically integrates the active cooling structure 1 with the traditional thermal system, and introduces an active cooling device at the hot end 22 to enhance the heat dissipation process, so that the system has stronger cooling capacity and thermal stability while maintaining the basic Stirling cycle logic.

[0092] For more details, please refer to the instruction manual. Figure 1 The Stirling refrigerator contains components such as a linear motor 26, a power piston 27, a gas distribution piston 28, and a vibration absorber 29. The linear motor 26 is the main drive source of the system. Under external electric drive, it drives the power piston 27 to reciprocate vertically, thereby forming a periodic sinusoidal pressure wave inside the compression chamber 23. This, in turn, drives the gas distribution piston 28 to reciprocate vertically synchronously. The movement of the gas distribution piston 28 lags behind the power piston 27 by a certain phase angle, forming a sinusoidal pressure wave in the expansion chamber 24 that has a phase difference with the pressure wave in the compression chamber 23.

[0093] The power piston 27 and the gas distribution piston 28, according to the motion curve and phase angle relationship designed in the system, achieve reciprocating simple harmonic motion in the vertical direction, thereby regulating and driving the working medium within the sealed cavity. The system is typically sealed and filled with a high-pressure working fluid, preferably ammonia. Under the action of the power piston 27 and the gas distribution piston 28, this working fluid circulates between the compression chamber 23 and the expansion chamber 24 along a specific path. In the forward working cycle, the high-pressure working fluid flows out of the compression chamber 23, passes sequentially through the radiator fins at the hot end 22, the regenerator 25, and the absorber fins at the cold end 21, and finally enters the expansion chamber 24. In the reverse stroke, the high-pressure working fluid returns from the expansion chamber 24 to the compression chamber 23 in the opposite direction, forming a closed reciprocating thermal cycle path.

[0094] During this cycle, the high-pressure working fluid expands and absorbs heat in the expansion chamber 24, generating cooling at the cold end 21; while it compresses and releases heat in the compression chamber 23, with the heat being released to the outside through the hot end 22. Based on the operating characteristics of the Stirling refrigerator, an active cooling structure 1 is integrated into the hot end 22, enabling the hot end 22 to receive active external cooling during operation, allowing the generated heat to be carried away in a timely manner, significantly improving the heat dissipation efficiency of the hot end 22.

[0095] Under this effect, the cooling capacity of the cold end 21 and the minimum operating temperature are optimized simultaneously, thereby enhancing the overall cooling performance and continuous operation stability of the Stirling refrigerator.

[0096] In addition, as shown in the figure, it is understandable that the vibration absorber 29 is used to buffer the mechanical vibration generated during the movement of the linear motor 26 and the piston, thereby improving the stability and reliability of the whole machine operation.

[0097] In one embodiment, refer to the appendix to the specification. Figure 4 According to another aspect of this application, this application further provides a refrigeration system, which mainly includes a first refrigeration module 31, a second refrigeration module 32 and an intermediate heat exchange module 33.

[0098] In this system, the cold end of the first refrigeration module 31 is used to output cooling capacity and can be selected as a compressor refrigeration unit, an air-cooled Stirling refrigerator, or other types of conventional refrigeration devices. The first refrigeration module 31 constitutes the upper-level cold source of the system; its output cooling capacity does not directly act on the load but is used to regulate the hot end temperature of the second refrigeration module 32. The second refrigeration module 32 adopts the Stirling refrigerator described in the above embodiment, as shown in the attached diagram. Figure 1 Its hot end 22 is equipped with an active cooling structure 1, which can perform forced convection heat exchange with the hot end 22 through the cooling medium, and has good thermal response speed and cooling capacity.

[0099] The cold end of the first refrigeration module 31 and the active cooling structure 1 of the second refrigeration module 32 are thermally coupled through an intermediate heat exchange module 33. The intermediate heat exchange module 33 can be in the form of a liquid cooling plate, a heat pipe structure, a plate-fin heat exchanger, etc., and is used to stably and efficiently transfer the cooling capacity output by the first refrigeration module 31 to the active cooling structure 1 of the Stirling refrigerator, so that the temperature of the hot end 22 is kept at a low level during operation.

[0100] Understandably, through intermediate heat exchange, the first refrigeration module 31 can continuously or intermittently cool the hot end 22 of the Stirling refrigerator during system operation, thereby effectively suppressing the temperature rise of the hot end 22, effectively extending the working range of the Stirling refrigerator, and increasing the minimum achievable temperature of the cold end 21 of the Stirling refrigerator.

[0101] Furthermore, this composite refrigeration system in this embodiment can maintain a separate structural arrangement with flexible connections, achieving a breakthrough in the system's cooling temperature limit through the subsequent connection of the intermediate heat exchange module 33. Additionally, it should be noted that while the refrigeration system proposed in this embodiment includes a first refrigeration module 31 and a second refrigeration module 32, in reality, additional refrigeration modules can be added according to actual needs and circumstances, such as a third refrigeration module, a fourth refrigeration module, etc. Similar to the arrangement of the first refrigeration module 31 and the second refrigeration module 32, when additional refrigeration modules are added, the cold end of the second refrigeration module 32 cooperates with the active cooling structure of the third refrigeration module. This process can be repeated to form a multi-stage refrigeration system.

[0102] In specific implementation, one optional implementation method can be found in the appendix to the instruction manual. Figure 1 and Figure 4 The first refrigeration module 31 is a conventional compressor refrigeration system. Its output cooling capacity is transferred to the heat exchange body 10 of the second refrigeration module 32 via the intermediate heat exchange module 33 to cool the internal cooling medium. Then, in the second refrigeration module 32, after being pre-cooled by the compressor refrigeration system, the cooling medium enters the heat exchange area of ​​the hot end 22 of the Stirling refrigerator at a lower temperature, further removing the heat released by the hot end 22, thereby suppressing the temperature rise of the hot end 22, increasing the temperature gradient between the hot end 22 and the cold end 21, and achieving the purpose of reducing the minimum temperature of the cold end 21.

[0103] In another embodiment, the first refrigeration module 31 adopts an air-cooled Stirling refrigerator, and the intermediate heat exchange module 33 can adopt a heat pipe structure to guide the cooling medium in the heat exchange body 10 to the cold end area of ​​the air-cooled Stirling refrigerator. After completing one cooling cycle, the medium flows back to the heat exchange body 10 of the active cooling structure 1 of the second refrigeration module 32. This can also achieve the purpose of reducing the extreme cold end temperature of the Stirling refrigerator.

[0104] In summary, it is understood that the refrigeration system proposed in this application can be flexibly selected and deployed according to cooling objectives, equipment conditions and integration requirements, thereby further reducing the hot end temperature and improving the cold end cooling limit capacity, which to a certain extent represents a significant breakthrough in Stirling refrigeration technology.

[0105] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An active cooling structure, characterized in that, include: Cooling medium source; The heat exchanger body has at least one inlet end and at least one outlet end; It has a flow channel inside, and the input end and the output end are both connected to the flow channel. The heat exchange body is at least partially attached to the outer wall of the hot end of the Stirling refrigerator so that the cooling medium can flow through the flow channel across the surface of the hot end of the Stirling refrigerator. A driving device is connected to a cooling medium source and a heat exchanger body. It is used to actively deliver cooling medium to the flow channel, so that the hot end of the Stirling refrigerator and the heat exchanger body can perform forced convection heat exchange, thereby reducing the cooling temperature limit of the cold end of the Stirling refrigerator.

2. The active cooling structure according to claim 1, characterized in that, The heat exchanger body includes a main body and a shell disposed on the outside of the main body. The flow channel is defined between the outside of the main body and the inside of the shell. The input end and the output end are both disposed on the shell. When the cooling medium flows through the flow channel, the cooling medium flows along at least a portion of the contour trajectory of the main body.

3. The active cooling structure according to claim 2, characterized in that, The heat exchange body further includes at least one partition, which is arranged in a ring, a near-ring, or an arc-shaped outline along the circumference of the body and is fixed to the side wall of the body near the shell in a vertical or inclined manner, so that the flow channel is divided into at least two branch channels by the partition. In operation, the cooling medium input to the heat exchanger can flow along the multiple branch channels.

4. The active cooling structure according to claim 3, characterized in that, The number of partitions is greater than or equal to two, and each pair of adjacent partitions together form a branch channel; and the partitions are arranged at preset intervals along the thickness direction of the main body, the preset intervals corresponding to the width of the corresponding branch channel; And / or, the partitions are all made of thermally conductive materials, so as to form, together with the main body, the heat exchange structure between the active cooling structure and the hot end of the Stirling refrigerator.

5. The active cooling structure according to any one of claims 1-4, characterized in that, The heat exchanger body has a recessed portion at the position corresponding to the input end; The recessed portion is connected to the flow channel and is used to guide the cooling medium to be pre-distributed or have its flow rate buffered before entering the flow channel.

6. The active cooling structure according to claim 5, characterized in that, A flow-diverting baffle is provided in the recessed portion, which is used to divert the cooling medium so that the cooling medium is distributed to at least two branches of the flow channel.

7. The active cooling structure according to claim 6, characterized in that, The number of input terminals and the number of output terminals are both one, and the input terminals and the output terminals are respectively located at the relative radial positions of the heat exchange body and are symmetrically arranged along the diameter direction of the heat exchange body.

8. The active cooling structure according to any one of claims 1-4, 6, and 7, characterized in that, The heat exchanger body is a sleeve-shaped structure, and the inner peripheral wall of the heat exchanger body is fitted to the outer wall of the hot end of the Stirling refrigerator.

9. A Stirling refrigerator, characterized in that, include: The cold end is used to absorb external heat to achieve a cooling effect. The hot end is thermally connected to the cold end and is used to release heat to the outside. The compression chamber and expansion chamber are used to compress and expand the working medium, respectively. The hot end is thermally coupled to the compression chamber, and the cold end is thermally coupled to the expansion chamber, thereby forming a closed thermodynamic working circuit in the Stirling refrigerator. A regenerator, located between the cold end and the hot end, is used to recover and reuse heat from the reciprocating working medium. The active cooling structure according to any one of claims 1-8 is disposed at the hot end and is used to actively cool the hot end.

10. A refrigeration system, characterized in that, include: The first refrigeration module has a cold end, which is used to output cooling capacity; The second refrigeration module employs the Stirling refrigerator as described in claim 9, wherein the hot end of the Stirling refrigerator is provided with an active cooling structure. The intermediate heat exchange module thermally couples the cold end of the first refrigeration module and the active cooling structure of the second refrigeration module, so that the first refrigeration module and the second refrigeration module form a composite refrigeration system. The first refrigeration module continuously or intermittently reduces the hot end temperature of the Stirling refrigerator to achieve a lower refrigeration temperature.

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