Energy storage heat exchanger resistant to phase change stress

Abstract

This invention discloses an energy storage heat exchange device resistant to phase change stress, relating to the field of refrigeration and energy storage equipment manufacturing technology. The invention aims to solve the technical problem of fatigue and tearing of the weld seam at the bottom of the heat exchange tube and the manifold caused by the physical displacement of the heat exchange tube due to the volume expansion of the internal phase change material. The invention provides an energy storage heat exchange device comprising: a sealed tank body with an internally defined sealed chamber, the bottom edge of which has inwardly recessed first and second receiving and abutment portions, in which a fluid manifold is housed; and the end of the inner heat exchange tube protruding from the wall surface and communicating with the manifold. Crucially, the sealed tank body is provided with a limiting support structure extending upward from the bottom surface and partially surrounding the inner heat exchange tube. This limiting support structure acts as a stress anchor point, directly transferring the medium expansion stress to the high-rigidity tank body, cutting off the path of stress transmission to the bottom weld seam. This invention ensures the long-term sealing reliability and service life of the device.

Description

Technical Field

[0001] This invention relates to the field of refrigeration and energy storage equipment manufacturing technology, and particularly to an energy storage and heat exchange device resistant to phase change stress. This device is especially suitable for mobile cold chain equipment, vehicle-mounted insulated cold storage systems, or solid-state phase change thermal management systems operating under conditions of frequent mechanical vibration and accompanied by deep thermal phase change cycles. Background Technology

[0002] With the rapid development of the mobile refrigeration and cold chain logistics industry, application scenarios such as vehicle-mounted mobile cold chain equipment have placed extremely stringent requirements on the "offline long-term insulation" capability of temperature control systems. To meet the need for continuous release of cooling capacity after power failure, the industry generally adopts energy storage devices with built-in phase change material (PCM) for latent heat storage. Traditional cold storage architectures typically involve laying heat exchange pipe networks inside the tank and distributing and collecting the system's refrigerant through external fluid manifolds.

[0003] In existing implementations (such as the thermoelectric composite microchannel energy storage heat exchange device disclosed in Chinese patent application CN122237240A), the ends of the microchannel heat exchange tubes are all connected to large-diameter fluid manifolds. Due to limitations in manufacturing processes and conventional piping layouts, these large-diameter, high-rigidity manifolds typically have to extend directly through the side wall or top cover of the energy storage tank. However, while this conventional structure can maintain stability in static environments, it reveals significant technical shortcomings when deployed in harsh application scenarios such as vehicle-mounted applications where high-frequency, multi-directional mechanical vibrations occur over extended periods. Because the energy storage tank is filled with phase change material, the tank itself is an inertial mass block; while the externally extending large manifolds and their connected compressor piping constitute another stress system. Under vibration conditions, the relatively large manifolds penetrating the wall essentially form a "cantilever beam" subjected to extremely unfavorable stress. Over time, the intense relative displacement shear force will generate extremely high stress concentration at the junction of the manifold and the thin wall of the energy storage tank, causing irreversible metal fatigue cracking in the weld seam, ultimately leading to serious equipment failure due to refrigerant leakage and causing severe cold chain disruption losses.

[0004] Simultaneously, when the equipment enters the cold storage state and the liquid phase change coolant in the tank undergoes a phase change to a solid state (freezing and solidification), the volume of the eutectic medium expands. Because the inner heat exchange tubes have a large flow-blocking and water-resistant area within the sealed chamber, this volume expansion generates a macroscopic physical thrust, forcing the inner heat exchange tubes to twist and shift. This internal deformation inevitably travels along the tube body to the weld at the bottom where the heat exchange tubes pass through the wall and intersect with the manifold. Under long-term, repeated freeze-thaw cycles, the bottom weld endures alternating shear and tearing stresses, eventually leading to metal fatigue and detachment, causing refrigerant leakage and ultimately, failure of the entire unit. Summary of the Invention

[0005] To address the shortcomings in the prior art, this invention provides an energy storage heat exchange device resistant to phase change stress, aiming to solve the technical problem in existing manifold cold storage heat exchangers where the internal phase change material undergoes a huge volume expansion during freezing and phase change, which pushes the inner heat exchange tube to undergo physical displacement, leading to fatigue, tearing, or even leakage at the bottom joint weld between the heat exchange tube and the manifold.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A heat storage device resistant to phase change stress is characterized by comprising a sealed tank, an inner heat exchange tube, and a fluid manifold; the sealed tank has a sealed chamber for containing a phase change medium, and a first and a second recessed recessing portion are respectively provided at opposite edges of the bottom of the sealed tank; the fluid manifold is at least partially housed within the recessing portion; the end of the inner heat exchange tube protrudes through the wall of the recessing portion and communicates with the fluid manifold; the sealed tank has a limiting support structure extending upward from its inner bottom surface, the limiting support structure at least partially surrounding the outer circumferential surface of the inner heat exchange tube in the region near the protruding end of the inner heat exchange tube, the limiting support structure being configured to restrict the physical displacement of the inner heat exchange tube when the phase change medium undergoes phase change volume expansion.

[0008] By employing a limiting support structure at the end of the heat exchange tube, this invention directly transfers and constrains the physical displacement and shear force generated by the volume expansion of the phase change medium onto the bottom surface of the highly rigid sealed tank through the addition of rigid constraint nodes. This improvement effectively cuts off the mechanical path of deformation stress transmission to the weak bottom through-wall weld, fundamentally eliminating the hidden danger of pipeline fatigue and weld failure caused by long-term freeze-thaw cycles, and significantly improving the tensile strength of the pipe connection and the long-term sealing reliability of the system.

[0009] In a preferred embodiment of the present invention, the limiting support structure includes a support protrusion, the two lateral ends of which surround the outer boundary of the inner heat exchange tube, and the end of the support protrusion is solidly connected to the inner wall of the sealed tank. By further adopting the above-mentioned technical features, the present invention constructs a high-strength three-dimensional stress-bearing anchoring base point in which the bottom surface, side wall, and support protrusion work together to bear the force. This design can effectively resist multi-directional and irregular ice expansion shear stress, ensuring that the support component itself does not yield deformation or break under heavy load and harsh working conditions, and maintaining a constant physical clamping effect.

[0010] In a preferred embodiment of the present invention, the top of the supporting protrusion is provided with an assembly chamfer near the edge of the inner heat exchange tube to provide guidance and prevent scratching of the tube wall during insertion of the inner heat exchange tube. By further employing the assembly chamfer, the present invention optimizes the factory-level assembly process. During mass blind insertion assembly of microchannel heat exchange tubes, the chamfer provides smooth physical guidance, avoiding scratches to the metal tube wall from sharp edges, ensuring the integrity of the heat exchange tube under high-pressure conditions, and improving manufacturing yield.

[0011] In a preferred embodiment of the present invention, the inner heat exchange tube extends in a reciprocating bending direction within the sealed chamber, and the lower bent section of the inner heat exchange tube is fixedly connected to the inner bottom surface of the sealed tank. The inner bottom surface of the sealed tank is provided with a positioning and limiting groove that matches the outer contour of the lower bent section, and the lower bent section is embedded in the positioning and limiting groove. By further employing the embedded cooperation between the lower bent section and the positioning and limiting groove, the present invention transforms the stress state of the bottom of the pipeline from a suspended point support to a stable line-surface combined support. Ice expansion stress is evenly distributed across the entire bottom cross-section of the sealed tank, effectively suppressing the overall lateral sway and deformation of the lower half of the heat exchange tube.

[0012] In a preferred embodiment of the present invention, the inner heat exchange tube has multiple vertical sections and bottom arc-shaped sections and top arc-shaped sections connecting adjacent vertical sections within the sealed chamber; the inner bottom surface of the sealed tank is provided with a positioning and limiting groove adapted to the outer contour of the bottom arc-shaped section, and the bottom arc-shaped section is embedded in the positioning and limiting groove and fixedly connected to the sealed tank. By further clarifying the arc-shaped geometric features of the tube section and conforming it to the bottom groove for fixation, the present invention strengthens the mechanical holding force of the microchannel continuous pipe network within the sealed chamber and eliminates the stress concentration dead angle in the bottom folding area during medium expansion.

[0013] In a preferred embodiment of the present invention, the depth of the positioning and limiting groove is smaller than the cross-sectional height or bending radius of the lower bending section; ribs are provided on both sides of the top of the positioning and limiting groove along the extension direction of the groove body, and the contact surface of the ribs with the lower bending section has a matching arc surface structure. By further limiting the depth of the positioning and limiting groove and providing ribs with a matching arc surface structure, on the one hand, the increased manufacturing cost and deterioration of thermal resistance caused by excessive thickening of the bottom of the tank are avoided; on the other hand, the matching arc surface of the ribs significantly expands the capillary wetting and effective adhesion area of ​​the liquid metal brazing filler metal during high-temperature brazing, increasing the mechanical shear strength of the weld.

[0014] In a preferred embodiment of the present invention, the inner heat exchange tube has an upper bend section located at the top, the lowest geometric point of which is situated above the maximum liquid level of the phase change medium after phase change solidification. By further raising the upper bend section as a whole above the maximum physically expanded liquid level, the present invention utilizes the principle of physical geometric space avoidance. This fundamentally resolves the axial lifting and pulling force generated at the bend in the top of the pipe system when the ice layer grows upward due to volume expansion, preventing the pipe network from being "pulled apart" from the inside.

[0015] In a preferred embodiment of the present invention, the inner wall of the sealed tank is further provided with a side wall support, which is fixedly connected to the side of the vertical section of the inner heat exchange tube. By further adding a side wall support and fixing it to the vertical section, the present invention provides a rigid lateral framework support for the slender microchannel tube that is highly susceptible to flexural instability. This effectively suppresses the risk of tube bending caused by longitudinal ice expansion and compression, and maintains the unobstructed flow of fluid.

[0016] In a preferred embodiment of the present invention, the outer bottom surface of the sealed tank is provided with a plurality of first heat exchange fins arranged at intervals, the plurality of first heat exchange fins jointly defining a first airflow channel; an outer convection member is provided on one outer side wall of the sealed tank, the interior of the outer convection member defining a second airflow channel; the fluid to be cooled is configured to flow sequentially through the first airflow channel and the second airflow channel. By further constructing a dual airflow channel orthogonally on the outer bottom side, the present invention fully utilizes the outer three-dimensional geometric envelope area of ​​the sealed tank, enabling the forced-circulation air to be cooled to absorb the latent cold lost at the bottom and the sensible heat of the main heat exchange surface of the side wall in sequence. This cascade heat exchange significantly improves the system's immediate external cooling efficiency and overall energy utilization rate.

[0017] In a preferred embodiment of the present invention, the outer convection member is a hollow tubular structure with internal ribs; a rectifier channel is further provided between the first airflow channel and the second airflow channel, the rectifier channel being composed of heat dissipation rectifier fins disposed on the side wall of the sealed tank. By further introducing the synergistic effect of the hollow tubular component with internal ribs and the corner heat dissipation rectifier fins, the present invention optimizes the external aerodynamic flow field distribution. The rectifier channel effectively reduces the "Karman vortex street" turbulent devortex dead zone generated when the airflow transitions at the corner, reduces the system-level wind resistance, and allows the airflow to enter the core heat exchange zone of the side wall in a uniform laminar state. At the same time, the heat dissipation rectifier fins can also conduct the cold energy in the energy storage tank to the rectifier channel, reducing the temperature of the fluid flowing through it.

[0018] In a preferred embodiment of the present invention, the inner heat exchange tube includes a first inner heat exchange tube and a second inner heat exchange tube, and the fluid manifold includes a first manifold, a second manifold, and a third manifold; the first manifold and the third manifold are both housed within the first accommodating clearance portion, and the second manifold is housed within the second accommodating clearance portion; the first manifold, the first inner heat exchange tube, the second manifold, the second inner heat exchange tube, and the third manifold are connected in series sequentially to form a fluid flow loop. By further cross-connecting the first to third manifolds and the two sets of inner heat exchange tubes, a uniformly distributed serpentine heat absorption temperature field is formed in the sealed chamber. This multi-segment continuous heat absorption path planning of the refrigerant effectively ensures the deep and uniform freezing of the phase change material and eliminates local phase change thermal dead zones within the energy storage tank.

[0019] In a preferred embodiment of the present invention, the fluid manifold further includes a fourth manifold and a fifth manifold, and the energy storage heat exchange device further includes an outer heat exchange pipe and a connecting pipe; the outer heat exchange pipe is disposed on the outer surface of the outer convection pipe on the side opposite to the sealed tank body, and the fourth manifold and the fifth manifold are respectively connected to the two ends of the outer heat exchange pipe; the first manifold, the first inner heat exchange pipe, the second manifold, the second inner heat exchange pipe, the third manifold, the connecting pipe, the fourth manifold, the outer heat exchange pipe, and the fifth manifold are connected in series to form a fluid flow loop. The cryogenic liquid refrigerant preferentially promotes efficient phase change ice storage on the inner side; after the refrigerant absorbs heat and its dryness increases, it transforms into a two-phase state, and is then transferred to the outer side to handle the sensible heat of the external air. This stepped pressing cycle based on phase enthalpy difference significantly improves the overall energy efficiency ratio (COP) of the entire unit during simultaneous cold storage and cold release operation.

[0020] In a preferred embodiment of the present invention, the main body of the sealed tank, the accommodating and abutting portion, and the limiting support structure are integrally formed. By further employing an integral molding manufacturing process, the present invention eliminates the stress fatigue risks introduced by mechanical tolerances and structural splicing in traditional split assembly, ensuring that all parts of the core load-bearing skeleton of the device have consistent mechanical transmission characteristics and high tensile and torsional rigidity.

[0021] In a preferred embodiment of the present invention, the main body of the sealed tank, the accommodating and abutting portion, the limiting support structure, the first heat exchange fins, and the heat dissipation and rectifying fins are integrally formed. By further integrating the airflow heat dissipation components with the main tank's load-bearing structure in a large-scale integral form, the present invention not only improves the overall mechanical load-bearing capacity but also eliminates the metal interface contact thermal resistance caused by assembly at the microscopic lattice level, ensuring that the cooling capacity within the phase change chamber can achieve efficient physical conduction.

[0022] In a preferred embodiment of the present invention, the inner heat exchange tube is a flat aluminum alloy heat exchange tube with multiple sets of microchannels inside, and the equivalent hydraulic diameter of each microchannel is between 0.8 mm and 2.2 mm. By further limiting the inner heat exchange tube to a flat porous microchannel with a micro equivalent hydraulic diameter, the present invention not only provides a considerable specific surface area within a limited volume to enhance heat transfer at the solid-liquid phase change boundary, but also balances the capillary heat transfer coefficient inside the tube with the macroscopic flow pressure drop of the refrigerant at a microscale, ensuring the high efficiency and stability of the refrigeration compressor operating system.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Reliable interface anti-vibration fatigue and leak-proof sealing performance: This invention places a large-diameter rigid fluid manifold in the first and second recessed accommodating and abutting parts on both sides of the tank bottom. This not only minimizes the external geometric dimensions but also solves the problem of the manifold being a "cantilever beam" in existing technologies, fundamentally reducing the cantilever alternating stress moment under vehicle mechanical vibration. At the same time, the limiting support structure extending upward from the bottom of the tank surrounds and clamps the microchannel flat tube on two orthogonal coordinate axes, resisting and distributing the phase change extrusion and vehicle vibration stress, ensuring the airtightness of the weld at the through-end face, and eliminating the risk of breakage and leakage.

[0025] 2. Highly reliable resistance to phase change volume expansion: By lifting the upper bending section and placing its lowest arc edge above the highest liquid level after complete solidification, the pull-out stress generated by ice expansion and sublimation is completely eliminated; combined with the positioning and limiting groove with convex ribs wrapped and welded on the bottom surface, and the side wall support in the middle section, this invention constructs a high-rigidity grid in the shape of a box beam composite in a limited cavity. Under long-term alternating freeze-thaw icing conditions, the microchannel flat tube bundle does not undergo irregular deformation, and its service life is significantly increased.

[0026] 3. Three-dimensional airflow circulation with extremely high heat transfer density: The first heat exchange fin and the side heat dissipation and rectification fins are integrated into the space at the bottom, which is made up by the bend of the containment and avoidance section. Under the premise of ensuring zero airflow loss and turbulence resistance on the outer wall, the air is induced to flow through the bottom first, and then be rectified and slide over the outer convection component with its own fins on the side, which greatly increases the convective surface area for releasing the cooling capacity of the whole unit. With the five manifolds in series with gradient heat exchange from the inside to the outside, the air duct is not prone to frost during long-term operation and has excellent heat exchange performance.

[0027] This invention innovatively constructs a structural mechanics system centered on "multi-level geometric concealment at the bottom + internal anti-phase change limiting rigid clamping," directly addressing the pipe tearing and leakage problem that is prone to occur in traditional accumulators during phase change and ice expansion. By applying high-rigidity constraints to key displacement release nodes such as the ends, bottom, and sidewalls of the inner heat exchange tubes, the macroscopic transmission path of phase change stress is altered. Shear failure forces are smoothly distributed and dissipated on the sealed tank, preventing pull-out fatigue of the weld between the internal microfluidic tubes and the external pressure-bearing manifold. Combined with the thermodynamic airflow path and pipeline tiered flow field design that connects the internal and external systems, this device significantly improves the overall heat storage density and transient heat exchange power of the system while ensuring long-term sealing under vehicle-mounted bumps and deep alternating freeze-thaw conditions, demonstrating significant technical reliability and commercial application value. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0029] Figure 1 This is a three-dimensional schematic diagram of the sealed tank and the receiving and avoiding part in an embodiment of the present invention.

[0030] Figure 2 This is a top view of the sealed tank in an embodiment of the present invention.

[0031] Figure 3 yes Figure 2 Schematic diagram of sectional view AA.

[0032] Figure 4 This is a three-dimensional sectional view of the sealed tank in an embodiment of the present invention. Figure 1 .

[0033] Figure 5 This is a three-dimensional sectional view of the sealed tank in an embodiment of the present invention. Figure 2 .

[0034] Figure 6 This is a three-dimensional schematic diagram of the energy storage heat exchange device in an embodiment of the present invention. Figure 1 .

[0035] Figure 7 3D schematic diagram of the energy storage heat exchange device in the embodiment of the present invention Figure 2 .

[0036] Figure 8 This is a cross-sectional view of a three-dimensional schematic diagram of the energy storage heat exchange device in this embodiment of the invention.

[0037] in, Figures 1 to 8 The top cover of the sealed tank is not shown in either of them. Detailed Implementation

[0038] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] To enable those skilled in the art and examiners to better understand the technical mechanism and implementation principle of the present invention, the present invention will be further analyzed in detail below with reference to the accompanying drawings and specific embodiments. It should be particularly noted that all directional terms in this specification (such as "up", "down", "left", "right", "inner", "outer", "lateral", "longitudinal", etc.) are merely for the convenience of describing the device in a normal working posture or gravity field with reference to the accompanying drawings, and do not represent any mandatory limitation on the actual vehicle mounting posture or absolute physical spatial coordinates of the device.

[0040] Example 1

[0041] This embodiment details the implementation scheme of a stress-tear-resistant bottom layer structure for an energy storage and heat exchange device that resists phase change stress. Figures 1 to 5 As shown.

[0042] The core external load-bearing frame of this energy storage heat exchange device is a sealed tank 10. The sealed tank 10 is not only a mechanical shell, but also defines a sealed chamber inside for filling and containing a phase change medium with energy storage characteristics. In this field, the phase change medium is typically a eutectic phase change salt solution prepared from sodium chloride, water, and a special nucleating agent. This type of solution, after absorbing the cooling energy of the refrigerant, can convert sensible heat into latent heat of phase change, undergoing a transformation from a liquid solution to solid eutectic ice crystals within a specific low-temperature range.

[0043] To prevent the "cantilever beam resonance fatigue fracture" problem of the manifold caused by the vehicle-mounted equipment traveling on rough and bumpy roads, the bottom of the sealed tank 10 has a first recessed relief portion 11 and a second recessed relief portion 12 at two opposite edges, formed by integral molding or deep drawing sheet metal processes. This inwardly recessed geometry allows the large-sized, high-rigidity fluid manifold to be at least partially (or completely) concealed within these two relief portions, resulting in a flat outer bottom surface of the entire unit.

[0044] Inside the sealed chamber, an inner heat exchange tube 20 is installed, which serves as the main network for heat exchange and is responsible for the flow of high-temperature or low-temperature refrigerant. Since the ends of the inner heat exchange tubes 20 must be connected to the main refrigerant pipeline, they directly penetrate the inner walls of the first and second receiving and avoiding parts 11 and communicate with the fluid manifold placed inside the receiving and avoiding parts.

[0045] However, phase change media exhibit irreversible physical phenomena during freezing phase transitions: the density decreases as the liquid phase transforms into the solid phase, causing the overall volume to expand (approximately 9%). This expansion generates a significant compressive force. The inner heat exchange tubes 20, densely distributed within the chamber, act as baffles bearing this force. Under the powerful physical push and lateral crushing of the macroscopic ice layer, the heat exchange tubes, originally inserted straight into the bottom receiving wall, undergo torsional displacement. Once this internal physical displacement occurs, shear stress will travel along the tube body to the root joint where the tube is welded to the bottom of the tank and the fluid manifold. This joint is highly susceptible to tearing after being subjected to alternating freeze-thaw stress over a certain period.

[0046] To address the aforementioned issues, this embodiment introduces a mechanical stress reconstruction design inside the sealed tank 10: a limiting support structure 13 is integrally formed extending upwards from the inner bottom surface of the sealed tank 10. The limiting support structure 13 is positioned above the area near the end of the inner heat exchange tube 20 where it will soon protrude from the wall of the receiving and abutment portion. Physically, the limiting support structure 13 at least partially surrounds and secures the outer circumferential surface of the inner heat exchange tube 20.

[0047] Specifically, such as Figure 4 , Figure 5 As shown, the limiting support structure 13 is a support protrusion protruding from the bottom surface. The two lateral ends of the support protrusion are like a pair of "clamps", which extend along the outer periphery of the inner heat exchange tube 20 in a tight fit, realizing lateral side clamping; more importantly, the back end of the support protrusion is not suspended, but extends directly to the rear and is solidly connected with the inner wall of the sealed tank 10.

[0048] This three-dimensional integrated anti-torsional node architecture alters the system's mechanical transmission pattern: when the upper phase change material freezes and expands, attempting to forcibly bend and push the inner heat exchange tube 20, the displacement stress on the tube body is forcibly cut off at its root by the support protrusion. The support protrusion, with its own rigid support against the bottom and sidewalls, smoothly transmits and dissipates this destructive shear thrust across the entire sealed tank 10. Consequently, the stress at the weld joint of the bottom fluid manifold approaches zero, solving the problem of phase change cycle tearing of the weld.

[0049] To ensure high-efficiency mass production and yield in the factory assembly line, a chamfer 131 with a certain angle is specially reserved at the top of the support protrusion, near the edge where the inner heat exchange tube 20 will be inserted. The presence of the chamfer 131 provides a funnel-like adaptive sliding guide when the operator blindly inserts the slender and thin-walled aluminum alloy inner heat exchange tube 20 downward through the narrow receiving and avoidance part, avoiding tube wall scratches caused by sharp metal corners hitting each other, thus ensuring that the internal microchannels do not burst when subjected to high-pressure refrigerant.

[0050] Meanwhile, this embodiment preferentially employs high-pressure casting or liquid forging processes, allowing the sealed tank body 10, the two accommodating and abutment sections, and the internal limiting support structure 13 to be directly formed into a single, integral metal structure in one piece. Furthermore, the inner heat exchange tube 20 is selected as a flat aluminum alloy heat exchange tube with multiple sets of internal microchannels, and the equivalent hydraulic diameter of the internal microchannels is strictly controlled between 0.8 mm and 2.2 mm. Although the thin-walled characteristics of the microchannels are sensitive to external stress (hence relying on the protection of the limiting support structure 13), the resulting enhanced heat transfer and extremely low thermal resistance shorten the heat conduction time of phase change energy storage, significantly improving the refrigeration and quick-freezing capabilities of the cold storage / vehicle refrigerator.

[0051] Example 2

[0052] Based on the root node stress isolation theory established in the above embodiments, this embodiment further describes how to utilize geometric layout and multi-dimensional pipeline constraint design to establish a complete long-segment anti-ice expansion and anti-torsion anchoring protection system within the phase change cavity. See details for further information. Figure 3 , Figure 4 , Figure 5 and Figure 8 .

[0053] Because it is necessary to maximize the heat exchange area within a limited cavity, the inner heat exchange tube 20 cannot be composed of a single straight tube. It extends in a continuous, serpentine, reciprocating bend along the direction of gravity within the sealed cavity. Specifically, the inner heat exchange tube 20 is divided into multiple vertically arranged straight tube sections, as well as bottom and top arc-shaped sections connecting these straight tube sections. These lower bends (i.e., the bottom arc-shaped sections) are the second most vulnerable area, after the end perforations, where stress is most concentrated.

[0054] In this embodiment, the inner heat exchange tube 20 presents a reciprocating vertical multi-segment serpentine loop within the sealed chamber, specifically including: multiple parallel vertical tube segments, a bottom arc segment connecting the bottom ends of adjacent vertical tube segments, and a top arc segment connecting the top ends of adjacent vertical tube segments.

[0055] As mentioned earlier, ice expansion will generate irregular thrust on the bent sections of the heat exchange flat tubes at the bottom and top.

[0056] Therefore, such as Figure 3 and Figure 4 As shown, on the bottom surface of the inner cavity of the sealed tank 10, all the bottom arc-shaped segments corresponding to the bottom of the inner heat exchange tube are integrally formed with a positioning and limiting groove 14 that bulges downward and whose arc radius completely matches the bottom arc-shaped segment.

[0057] During installation, the arc-shaped folded head at the bottom of the heat exchange tube is fully embedded into the positioning and limiting groove 14 and brazed with a large area at the bottom of the tank. This changes the physical fixation of the bottom of the inner flat tube from a single-point fusion welding to a physical groove constraint with a large contact arc surface, which can effectively resist the downward deformation and displacement caused by ice expansion.

[0058] Therefore, in addition to root fixation, this device specifies that the lower bent section of the inner heat exchange tube 20 is tightly fitted and fixedly connected to the inner bottom surface of the sealed tank 10. However, planar welding at the bend of the flat tube on a smooth metal surface has the defects of easy slippage in positioning and extremely poor shear strength.

[0059] In this embodiment, a positioning and limiting groove 14, adapted to the outer geometric contour of the bottom arc-shaped section, is machined (or integrally cast) on the inner bottom surface of the sealed tank 10. Before the assembly enters the high-temperature brazing furnace, all the bottom arc-shaped sections of the inner heat exchange tubes 20 are deeply embedded in the grooves of the positioning and limiting groove 14. This embedding method changes the fixation of the bottom of the pipeline from the unreliable "point" or "line" contact of traditional processes to surface contact.

[0060] However, while deep grooves are robust, they necessitate localized thickening of the bottom surface of the sealed tank 10. This not only wastes aluminum material but, more seriously, increases the material's inherent thermal resistance when the cooling energy from the bottom phase change is conducted outwards. To balance lightweight design and high strength, this embodiment designs the geometric depth of the positioning and limiting groove 14 to be smaller than the cross-sectional height and bending radius of the lower bending section, i.e., adopting a "shallow groove" strategy.

[0061] To compensate for the insufficient enveloping force of the shallow groove, symmetrically raised ribs 15 are provided on both sides of the top opening of the positioning and limiting groove 14, extending along the longitudinal direction of the groove. The ribs 15 not only further clamp the pipe, but more importantly, the inner surface of the ribs 15 that contacts the bottom arc-shaped pipe wall is machined into a matching arc-shaped structure that conforms to the outward convexity of the pipe wall. During large-area eutectic brazing in a high-temperature furnace exceeding 600 degrees Celsius, this matching narrow-slit arc-shaped surface acts like a capillary pump on a microscopic scale, inducing the liquid aluminum-based brazing filler metal to rapidly rise and fill every gap due to surface tension. The resulting solidified weld has a mechanical shear pull-out force several times higher than that of conventional flat welding, fundamentally solving the problem of bottom deformation.

[0062] To prevent damage to the upper part of the equipment, the upper bend section (i.e., the top arc section) of the inner heat exchange tube 20 is intentionally designed with its geometric lowest point (lower edge of the U-bend) at the Z-axis elevation above the maximum liquid level of the phase change medium after it has completed its freezing phase change and solidification. In other words, even if the ice layer below generates an upward lifting force due to volume expansion, it will not be able to reach the suspended top arc section before the ice layer completely hardens and stops growing, thus effectively mitigating the risk of axial forceful "tube pulling".

[0063] like Figure 8 As shown, inside the sealed tank 10, on the inner side of the opposite solid sidewall of the heat exchange sidewall 17, there is an integrally formed transversely protruding sidewall support 16 (in cross-section). Figure 3 The upper part is presented as a stepped solid platform. The vertical side surfaces of the ends of the first inner heat exchange tube 21 and the second inner heat exchange tube 22 are fixed to the plane of the side wall support 16 by brazing in a vacuum furnace with high-toughness aluminum-silicon brazing flux.

[0064] The side wall support 16 directly forms a three-dimensional stress-bearing skeleton network with the original cavity-suspended microchannel network and the side shell, which can greatly absorb the slippage stress generated by the phase change volume expansion in the horizontal tangential direction.

[0065] In this embodiment, the first end of the inner heat exchange tube 20 is inserted into the manifold placed in the first receiving and avoiding part 11. Starting from the first end, the inner heat exchange tube 20 is pressed against the heat exchange side wall 17 and moves upward, then bends downward, then bends upward again, and after at least three bends, the second end of the inner heat exchange tube 20 is inserted into the manifold placed in the second receiving and avoiding part 12.

[0066] In some embodiments, the inner heat exchange tube 20 includes a plurality of vertical sections, with an arc-shaped section between adjacent vertical sections; the first and last two vertical sections form the two ends of the inner heat exchange tube 20, respectively passing through the outer walls of the first receiving and clearance portion 11 and the second receiving and clearance portion 12. Thus, the first vertical section with the first end is connected to the heat exchange sidewall by brazing, and a portion of the last vertical section with the second end is connected to the sidewall support portion 16 by brazing.

[0067] Example 3

[0068] Example 3, building upon the aforementioned safety baseline of ensuring absolutely no system leakage, discloses the "multi-layer cascade external air duct coordination" and "five-stage manifold energy tiered allocation" schemes pioneered by this device to achieve ultimate cooling efficiency. For example... Figure 6 and Figure 7 As shown.

[0069] In terms of the aerodynamics of the external flow field handling the interaction of external hot and cold fluids, the sealed tank 10 is not a bare rectangular block. Its outer bottom surface is integrally cast with multiple spaced-apart first heat exchange fins 41. The gaps between these arrays of first heat exchange fins 41 collectively define a first airflow channel through which the airflow passes in parallel; the first heat exchange fins 41 are perpendicular to the heat exchange sidewall 17. Simultaneously, on one side of the main heat exchange outer wall—the heat exchange sidewall 17—an outer convection member 42 is brazed. The outer convection member 42 is selected as a hollow tubular channel structure with internal fins, and its internal through-cavity forms a second airflow channel.

[0070] The system's fan drives the fluid to be cooled (such as return air in a car refrigerator), which is forced into a zigzag cascade flow: it preferentially blows through the first airflow channel at the bottom. Although the bottom surface is not the main cooling surface, due to thermodynamic laws, the heavy cold air sinking to the bottom often leaks cold here. After the airflow achieves preliminary recovery of the leaked latent cold at the bottom surface, it then comes to the rectified flow channel formed by the heat dissipation rectifier fins 43 densely distributed at the corners of the side walls. The rectifier flow channel, like a comb, disperses the large-scale reverse vortex resistance zone caused by right-angle turns, adjusting the airflow from turbulent flow to parallel and uniform laminar flow. Finally, the laminar air vertically enters the second airflow channel, and convective heat transfer occurs with the core main phase change cooling wall surface, achieving the effect of squeezing out the maximum cooling power with the minimum fan power. Moreover, the sealed tank body 10, the bottom receiving and avoidance part, the limiting support structure 13, together with the external first heat exchange fins 41 and the heat dissipation rectifier fins 43 of the transition section, are all integrally formed by a die-casting machine.

[0071] In the flow field topology of the internal refrigeration system, compared to the traditional two-pipe inlet / outlet configuration, this device is equipped with five fluid manifolds.

[0072] In terms of location: the first manifold 31 and the third manifold 33 are both placed inside the first receiving and clearance portion 11 at the bottom of the sealed container 10, and are physically independent; the second manifold 32 is located in the second receiving and clearance portion 12 opposite to the first receiving and clearance portion 11; the fourth manifold 34 is installed on the upper half of the distal end of the outer convection member 42, and the corresponding fifth manifold 35 is installed on the lower half of the same side. Furthermore, an outer heat exchange tube 50, also with a microchannel structure, is fixed to the outermost surface of the outer convection member 42, which faces away from the sealed container 10. The two ends of the outer heat exchange tube 50 are respectively connected to the upper fourth manifold 34 and the lower fifth manifold 35. The inner heat exchange tube 20 is divided into a first inner heat exchange tube 21 and a second inner heat exchange tube 22.

[0073] At this point, the system establishes a series fluid loop with reverse temperature slip, and the flow path is as follows:

[0074] After being throttled by the expansion valve, the high-temperature and high-pressure liquid refrigerant forms a low-temperature two-phase wet vapor (at which point the liquid content is the highest and the temperature is the lowest). The refrigerant is introduced into the system through the first manifold 31, passes through the first inner heat exchange tube 21, and directly undergoes the maximum latent heat exchange in the first phase change temperature zone. After reaching the second manifold 32, it enters the second inner heat exchange tube 22, which is connected to the second manifold, and continues to release cold energy. After flowing through the second inner heat exchange tube 22, the refrigerant flows into the third manifold 33.

[0075] In some embodiments, the refrigerant does not return directly to the compressor. Instead, it flows through a connecting pipe 60 spanning the surface of the device. One end of the connecting pipe 60 is connected to the outlet of the third manifold, and the other end is connected to the fourth manifold 34. Thus, the refrigerant is delivered to the fourth manifold 34, and then passes through the outer heat exchanger 50. At this point, although the refrigerant temperature has risen somewhat, it is still lower than the temperature of the air flowing through the duct. Therefore, in this region, the low-quality sensible enthalpy difference is used to cool the air flowing through the outer heat exchanger 50 again. Finally, the refrigerant collects in the fifth manifold 35 and returns to the external circulation. This five-stage series structure, based on the second law of thermodynamics, matches the dynamic distribution glide curves of temperature, pressure, and dryness of the working fluid at various points in the evaporator, raising the overall coefficient of performance (COP) of the refrigeration system to a new level.

[0076] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A heat storage and heat exchange device resistant to phase change stress, characterized in that: The device includes a sealed tank (10), an inner heat exchange tube (20), and a fluid manifold. The sealed tank (10) has a sealed chamber for containing a phase change medium. At opposite edges of the bottom of the sealed tank (10), there are a first receiving clearance portion (11) and a second receiving clearance portion (12) recessed into the inner side of the sealed chamber. The fluid manifold is at least partially housed within the receiving clearance portion. The end of the inner heat exchange tube (20) extends through the wall of the receiving clearance portion and communicates with the fluid manifold. The sealed tank (10) has a limiting support structure (13) extending upward from its inner bottom surface. The limiting support structure (13) at least partially surrounds the outer circumferential surface of the inner heat exchange tube (20) in the area near the end of the inner heat exchange tube (20) where it protrudes. The limiting support structure (13) is configured to restrict the physical displacement of the inner heat exchange tube (20) when the phase change medium undergoes phase change volume expansion.

2. The energy storage and heat exchange device for resisting phase change stress according to claim 1, characterized in that, The limiting support structure (13) includes a support protrusion, the two lateral ends of which surround the outer boundary of the inner heat exchange tube (20), and the end of the support protrusion is solidly connected to the inner wall of the sealed tank (10).

3. The energy storage and heat exchange device for resisting phase change stress according to claim 2, characterized in that, The top of the support protrusion is provided with an assembly chamfer (131) near the edge of the inner heat exchange tube (20) to provide guidance and prevent scratches on the tube wall when the inner heat exchange tube (20) is inserted.

4. The energy storage and heat exchange device for resisting phase change stress according to claim 1, characterized in that, The inner heat exchange tube (20) extends in a reciprocating bending direction within the sealed chamber. The lower bent section of the inner heat exchange tube (20) is fixedly connected to the inner bottom surface of the sealed tank (10). The inner bottom surface of the sealed tank (10) is provided with a positioning and limiting groove (14) that matches the outer contour of the lower bent section. The lower bent section is embedded in the positioning and limiting groove (14).

5. The energy storage and heat exchange device for resisting phase change stress according to claim 1 or 4, characterized in that, The inner heat exchange tube has multiple vertical sections and bottom arc sections and top arc sections connecting adjacent vertical sections in the sealed chamber; the inner bottom surface of the sealed tank (10) is provided with a positioning and limiting groove (14) that matches the outer contour of the bottom arc section, and the bottom arc section is embedded in the positioning and limiting groove (14) and fixedly connected to the sealed tank (10).

6. The energy storage and heat exchange device for resisting phase change stress according to claim 4, characterized in that, The depth dimension of the positioning and limiting groove (14) is smaller than the cross-sectional height or bending radius of the lower bending section; the top two sides of the positioning and limiting groove (14) are provided with ribs (15) along the extension direction of the groove body, and the contact surface of the ribs (15) and the lower bending section is an adapted arc surface structure.

7. The energy storage and heat exchange device for resisting phase change stress according to claim 4, characterized in that, The inner heat exchange tube (20) has an upper bend section located at the top, and the lowest point of the upper bend section is located above the maximum liquid level of the phase change medium after phase change solidification in the height direction.

8. The energy storage and heat exchange device for resisting phase change stress according to claim 4, characterized in that, The inner wall of the sealed tank (10) is also provided with a side wall support (16), which is fixedly connected to the side of the vertical section of the inner heat exchange tube (20).

9. The energy storage and heat exchange device for resisting phase change stress according to claim 1, characterized in that, The outer bottom surface of the sealed tank (10) is provided with a plurality of first heat exchange fins (41) arranged at intervals, and the plurality of first heat exchange fins (41) together define a first airflow channel; an outer convection member (42) is provided on one outer side wall of the sealed tank (10), and the interior of the outer convection member (42) defines a second airflow channel; the fluid to be cooled is configured to flow through the first airflow channel and the second airflow channel in sequence.

10. The energy storage and heat exchange device for resisting phase change stress according to claim 9, characterized in that, The outer convection component (42) is a hollow tubular structure with internal ribs; a rectifier channel is also provided between the first airflow channel and the second airflow channel, and the rectifier channel is composed of heat dissipation rectifier fins (43) provided on the side wall of the sealed tank (10).

11. The energy storage and heat exchange device resistant to phase change stress according to claim 9 or 10, characterized in that, The inner heat exchange tube includes a first inner heat exchange tube (21) and a second inner heat exchange tube (22), and the fluid manifold includes a first manifold (31), a second manifold (32), and a third manifold (33). The first manifold (31) and the third manifold (33) are both housed in the first receiving and clearance portion (11), and the second manifold (32) is housed in the second receiving and clearance portion (12); The first manifold (31), the first inner heat exchanger (21), the second manifold (32), the second inner heat exchanger (22), and the third manifold (33) are connected in series to form a fluid flow loop.

12. The energy storage and heat exchange device for resisting phase change stress according to claim 11, characterized in that, The fluid manifold also includes a fourth manifold (34) and a fifth manifold (35), and the energy storage heat exchange device also includes an outer heat exchange pipe (50) and a connecting pipe (60); the outer heat exchange pipe (50) is disposed on the outer surface of the outer convection pipe (42) away from the sealed tank (10), and the fourth manifold (34) and the fifth manifold (35) are respectively connected to the two ends of the outer heat exchange pipe (50); The first manifold (31), the first inner heat exchanger (21), the second manifold (32), the second inner heat exchanger (22), the third manifold (33), the connecting pipe (60), the fourth manifold (34), the outer heat exchanger (50), and the fifth manifold (35) are connected in series to form a fluid flow loop.

13. The energy storage and heat exchange device for resisting phase change stress according to any one of claims 1 to 10 and 12, characterized in that, The main body of the sealed tank (10), the accommodating and abutting part, and the limiting support structure (13) are integrally formed.

14. The energy storage and heat exchange device for resisting phase change stress according to claim 10, characterized in that, The main body of the sealed tank (10), the accommodating and abutting part, the limiting support structure (13), the first heat exchange fin (41), and the heat dissipation and rectifying fin (43) are integrally formed.

15. The energy storage and heat exchange device for resisting phase change stress according to claim 1, characterized in that, The inner heat exchange tube (20) is a flat aluminum alloy heat exchange tube with multiple sets of microchannels inside, and the equivalent hydraulic diameter of each microchannel is between 0.8 mm and 2.2 mm.

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