Thermal buffer for enhancing melting heat absorption of phase-change material by using elastic potential energy

Abstract

The invention relates to the technical field of electronic equipment thermal management, in particular to an electronic equipment thermal buffer device suitable for missile-borne, spacecraft and other environments facing extreme high thermal load and severe temperature fluctuation. Comprising a packaging base body and a phase-change material, a partition plate is fixedly installed in the packaging base body and on one side of the phase-change material, a pressing plate is arranged on one side of the partition plate, and a spring winding type wire pulling device is arranged on the other side of the partition plate; the clockwork spring winding type wire pulling device comprises a reel for winding a pulling wire, a first bevel gear fixedly mounted on the reel, and a clockwork spring in transmission connection with the first bevel gear; a through hole is formed in the center of the phase change material, and a pulley is arranged on the inner wall of the packaging substrate corresponding to one end, far away from the pressing plate, of the through hole; the pull wire penetrates through the partition plate, the pressing plate and the through hole and bypasses the pulley, and the tail end of the pull wire is fixedly connected to the pressing plate. The device operates completely based on the mechanical energy storage principle, the transmission mechanism is efficient and stable, the heat conduction efficiency and the interface heat exchange capacity are high, and the heat dissipation performance consistency is good.

Description

Technical Field

[0001] This invention relates to the technical field of thermal management of electronic devices, and more particularly to a thermal buffer device suitable for electronic devices such as missiles and spacecraft that face extreme high heat loads and severe temperature fluctuations; more specifically, this invention relates to a thermal buffer that utilizes elastic potential energy to enhance the heat absorption during the melting of phase change materials. Background Technology

[0002] In modern electronic devices, with the continuous increase in component integration, heat dissipation has gradually become a crucial factor restricting the performance and stability of electronic equipment. This is especially true in the field of heat dissipation for electronic devices within confined spaces (such as missile and aircraft-borne electronic components), where heat dissipation is even more critical. If heat dissipation is not timely, excessively high temperatures of electronic components can lead to equipment malfunctions and even seriously impact combat missions and national defense security. Currently, thermal design for missile-borne electronic equipment mainly focuses on sensible heat storage and latent heat storage. Sensible heat storage technology utilizes the temperature rise of the device's own metal components to store energy. The advantage of this technology lies in its simplicity; however, due to its relatively low energy density, it often requires a large heat dissipation system to meet the requirements. Due to the weight and volume limitations of missile-borne systems, the application of sensible heat storage technology faces many challenges and is gradually failing to meet the heat dissipation needs of modern electronic equipment. Latent heat storage technology uses phase change materials (such as paraffin) to maintain a stable temperature during heat absorption, effectively mitigating the impact of temperature fluctuations on the device. Compared to sensible heat storage technology, latent heat storage has a higher energy density and is a more ideal heat dissipation solution. Organic phase change materials such as paraffin wax possess excellent physicochemical properties, including high latent heat of fusion, stable physicochemical properties, and non-toxicity and non-corrosiveness, effectively meeting the heat dissipation requirements of electronic devices. For example, Chinese Patent 202411777503X discloses "A Paraffin Wax and Liquid Metal Composite Phase Change Energy Storage Heat Sink," authorized announcement number CN119255579B. This energy storage heat sink includes a separate upper shell and a lower shell. The upper shell has an upper heat dissipation groove, and the lower shell has a lower heat dissipation groove. The upper shell is embedded in the lower heat dissipation groove, forming a heat dissipation cavity between the lower and upper heat dissipation grooves. The heat dissipation cavity forms a liquid metal filling cavity at the corresponding position of a high-power chip and a paraffin wax filling cavity at the corresponding position of a low-power chip. The paraffin wax filling cavity and the liquid metal filling cavity are separated by an annular liquid cooling channel. Multiple air cooling channels are formed through the bottom of the lower shell. This heat sink combines low-melting-point liquid metal with traditional phase change energy storage heat sinks. Utilizing the high thermal conductivity of liquid metal, it rapidly conducts heat from high-power chips to the phase change material's heat storage area, effectively solving heat dissipation problems in scenarios with high overall thermal capacity requirements for electronic components and the need for rapid temperature equalization of large chips. However, on the other hand, the low thermal conductivity and slow heat dissipation rate of these phase change materials limit their application range, especially in the field of missile-borne systems where rapid heat dissipation is required, where they exhibit significant shortcomings. Existing phase change thermal buffers suffer from poor thermal conductivity of phase change materials, resulting in the inability to quickly transfer and uniformly absorb heat. Especially during sudden increases in heat generation, problems such as localized overheating, large temperature fluctuations, and delayed heat dissipation easily occur, severely affecting the stability and lifespan of electronic devices. To address these issues, recent research has mainly focused on enhancing the thermal conductivity of phase change materials by adding high thermal conductivity materials such as fins, porous materials, and nanoparticles.These measures can improve the thermal conductivity of phase change materials to some extent, but they still face the problem of limited heat absorption. In traditional heat dissipation equipment, after the phase change material attached to the heat dissipation surface melts upon absorbing heat, the remaining phase change material cannot automatically move towards the heating wall. The phase change heat absorption process cannot continue to occur in close contact with the wall, resulting in the interface failing to achieve ideal heat dissipation performance. Especially in applications with high safety requirements, the temperature may rise sharply, and existing technologies cannot provide sufficient thermal protection. There is an urgent need for a thermal buffer system that is both stable and reliable, and has strong thermal protection capabilities. Another Chinese patent application, 202310347984X, discloses "A Bionic Phase Change Heat Buffer" (publication number CN116518782A). This heat buffer includes fins, a heat buffer cavity, a phase change material, and an elastic piston actuator. The fins are arranged at the upper end of the heat buffer cavity, and several hollow bosses are provided at the upper and lower ends of the heat buffer cavity. The phase change material is filled in the heat buffer cavity. The elastic piston actuator is located at the center of the heat buffer cavity and is composed of a shape memory spring, a bias spring, and a porous mesh plate. One end of the bias spring and the shape memory spring are fixed to the upper and lower surfaces of the porous mesh plate, respectively, and the other end is connected to the inner wall of the hollow bosses of the heat buffer cavity. This heat buffer utilizes an elastic piston actuator to achieve continuous and stable semi-active contact melting heat transfer enhancement, providing a solution for efficient thermal control of airborne directed energy weapons under intermittent short-term high heat flux. However, due to the inherent defects of the elastic piston actuator, such as the limited extension length of the spring, short extension time, and rapid attenuation of the driving force as the spring extends, this method suffers from drawbacks. The defects introduced by this spring-type actuator affect the full and stable performance of the thermal buffer. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the purpose of this invention is to provide a thermal buffer that utilizes elastic potential energy to enhance the melting and heat absorption of phase change materials. It operates based on the principle of mechanical energy storage, has a highly efficient and stable transmission mechanism, strong heat conduction efficiency and interfacial heat exchange capacity, and good heat dissipation performance consistency. It provides a stable, reliable thermal buffer system with strong thermal protection capabilities for electronic equipment in the missile field that requires rapid heat dissipation.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The present invention discloses a heat buffer for enhancing the melting and heat absorption of phase change material using elastic potential energy, comprising an encapsulation substrate and a phase change material disposed within the encapsulation substrate. A partition is fixedly installed inside the encapsulation substrate on one side of the phase change material. A pressure plate is disposed on the side of the partition facing the phase change material, and a spring-wound cable pulling device is disposed on the side away from the phase change material. The spring-wound cable pulling device includes a spool for winding the cable, a first bevel gear fixedly mounted on the spool, and a spring drivingly connected to the first bevel gear. A through hole is provided at the center of the phase change material, and a pulley is disposed on the inner wall of the encapsulation substrate corresponding to the end of the through hole away from the pressure plate. The cable passes through the partition, the pressure plate, and the through hole, wraps around the pulley, and its end is fixedly connected to the pressure plate.

[0005] With this solution, the transmission mechanism of the thermal buffer is efficient and stable, the wire pulling device has a long working distance and small force variation, strong heat conduction efficiency and interface heat exchange capacity, and good heat dissipation performance consistency.

[0006] Preferably, the spring is wound around the gear shaft of the second bevel gear, which is in constant mesh with the first bevel gear.

[0007] With this scheme, during energy storage, the first bevel gear drives the mainspring through the second bevel gear; during release, the mainspring drives the second bevel gear and the first bevel gear to rotate in opposite directions.

[0008] Preferably, a shaft seat is fixedly installed on the partition, and the reel is rotatably mounted on the shaft seat.

[0009] With this solution, the bearing can stably support the reel.

[0010] Preferably, a first spur gear is fixedly mounted on the second bevel gear and is coaxially arranged. The spring is wound around the gear shaft of the second spur gear, and the second spur gear and the first spur gear are constantly meshed.

[0011] This design lengthens the transmission path from the mainspring to the first bevel gear and allows for flexible setting of the transmission ratio.

[0012] Preferably, a mirror-symmetric shaft seat is fixedly installed on the partition plate, and both ends of the spool are rotatably mounted on the shaft seat. Each end of the spool is fixedly connected to a first bevel gear; the end of the pull wire is wound around the middle of the spool between the two first bevel gears.

[0013] With this solution, the two ends of the scroll are subjected to uniform force.

[0014] Preferably, the bearing seat has a mirror-symmetric structure, and the two ends of the reel are rotatably mounted on the bearing seat.

[0015] With this solution, the two ends of the scroll are subjected to uniform force.

[0016] Preferably, a heat-conducting fin is provided on the inner wall of the encapsulation substrate at the other end of the phase change material away from the pressure plate.

[0017] This solution can increase the heat dissipation area of ​​the inner wall of the encapsulation substrate and improve the heat exchange efficiency between the inner wall of the encapsulation substrate and the phase change material.

[0018] The technical effects and advantages of this invention are as follows: 1) This invention provides stable and sustained mechanical pressure through a spring-loaded energy storage device, ensuring that the phase change material remains in close contact with the heat source throughout the phase change process, thereby significantly improving heat conduction efficiency and interfacial heat exchange capacity, and overcoming the problem of decreased heat dissipation performance in traditional equipment in the later stages. 2) A transmission mechanism composed of pulleys and cables is used to achieve efficient and stable transmission of the spring force to the pressure plate. This structure features flexible layout, small footprint, and high transmission efficiency, making it particularly suitable for deployment in equipment environments with strictly limited space, such as missile launchers. 3) A rib structure is designed and processed on the heat conduction surface, which significantly improves the heat dissipation and diffusion capacity by increasing the effective heat dissipation area and enhancing the local turbulence effect, thereby accelerating the heat absorption rate of the phase change material and improving the overall heat dissipation efficiency. 4) It operates entirely based on the principle of mechanical energy storage, requiring no external power supply such as electricity or gas. It has the advantages of simple structure, high reliability, and wide applicability, and is especially suitable for heat dissipation of electronic equipment under high reliability, strong vibration, and harsh operating conditions. Attached Figure Description

[0019] Figure 1 This is a cross-sectional structural diagram of an embodiment of the present invention.

[0020] Figure 2 This is a cross-sectional structural diagram of another embodiment.

[0021] Figure 3 for Figure 2 A partial three-dimensional structural diagram of the embodiment. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1As shown, the heat buffer for enhancing the melting and heat absorption of phase change material using elastic potential energy, as described in this invention, includes an encapsulation substrate 1 and a phase change material 2 disposed within the encapsulation substrate 1. The encapsulation substrate 1 is made of a metal material with good thermal conductivity, and its bottom plate serves as a heat conduction surface. The phase change material 2 is a material such as paraffin wax, which is solid at room temperature but changes phase to liquid upon heating. The phase change material 2 is pre-formed into a block shape with a cross-sectional shape adapted to the inner cavity of the encapsulation substrate 1. A partition 3 is fixedly installed inside the encapsulation substrate 1 on one side of the phase change material 2. The edge of the partition 3 is fixedly connected to the inner wall of the encapsulation substrate 1, dividing the interior of the encapsulation substrate 1 into upper and lower chambers. The phase change material 2 is located in the lower chamber. A pressure plate 4 is provided on the side of the partition 3 facing the phase change material 2, and a spring-wound pull device is provided on the side away from the phase change material 2. The pressure plate 4 is located in the lower chamber above the phase change material 2, and the spring-wound pull device is located in the upper chamber and installed on the upper surface of the partition 3. The pressure plate 4 is separated from the inner wall of the encapsulation substrate 1, allowing it to slide up and down within the inner cavity of the encapsulation substrate 1.

[0024] The spring-winding cable pulling device includes a spool 5 for winding the cable 9, a first bevel gear 6 fixedly mounted on the spool 5, and a spring 7 driven by the first bevel gear 6. A spring is a power device that converts the elastic potential energy of a wound steel bar into mechanical energy. Its core is composed of a highly elastic steel bar, which drives mechanical operation through winding to store and release energy. In this embodiment, one end of the spring 7 is fixedly connected to a stationary partition 3, and the other end is fixedly connected to a rotatable gear. The rotation of the gear winds the spring 7 to obtain elastic potential energy. A through hole 8 is provided in the center of the phase change material 2. A pulley 10 is provided on the inner wall of the encapsulation substrate 1 corresponding to the end of the through hole 8 away from the pressure plate 4. The cable 9 passes through the partition 3, the pressure plate 4, and the through hole 8, wraps around the pulley 10, and is fixedly connected at its end to the pressure plate 4. The elastic potential energy of the tightly wound spring 7 winds one end of the pull wire 9 around the spool 5, and the other end of the pull wire 9 passes over the pulley 10 to pull the pressure plate 4, applying pressure to the phase change material 2 through the traction of the pressure plate 4. After the lower end of the phase change material 2 is heated and changes phase into liquid, the pressure plate 4 moves downward under the traction of the pull wire 9, pushing the remaining part of the phase change material 2 to always be in close contact with the heat conduction surface of the base plate, thereby improving the heat conduction efficiency.

[0025] like Figure 1As shown, in the first embodiment of the present invention, the mainspring 7 is wound around the gear shaft of the second bevel gear 61, which is constantly meshed with the first bevel gear 6. Each end of the mainspring 7 has a connection point; the outer connection point extends upward and is fixedly connected to the back of the second bevel gear 61, while the inner connection point extends downward and is fixedly connected to the upper surface of the partition 3. Rotating the first bevel gear 6 with a tool can drive the spool 5 and the second bevel gear 61 to rotate. When the spool 5 rotates, the upper end of the pull wire 9 can be wound onto or released from the spool 5. When the second bevel gear 61 rotates, the mainspring 7 can be wound tightly or released.

[0026] As a further improvement to this embodiment, the axis of the spool 5 is parallel to the upper surface of the partition 3, and a bearing seat 51 is fixedly installed on the partition 3. The spool 5 is rotatably mounted on the bearing seat 51. A bearing or bushing is provided between the spool 5 and the bearing seat 51 to minimize the frictional resistance between them, so that the spool 5 can rotate in the bearing seat 51.

[0027] As another embodiment of the present invention, such as Figure 2 , Figure 3 As shown, a first spur gear 62 is coaxially mounted on the second bevel gear 61. The spring 7 is wound around the gear shaft of the second spur gear 63. Each end of the spring 7 has a connection point; the outer connection point extends upwards and is fixedly connected to the back of the second spur gear 63, while the inner connection point extends downwards and is fixedly connected to the upper surface of the partition 3. The second spur gear 63 is constantly meshed with the first spur gear 62. Rotating the first bevel gear 61 using a tool can drive the spool 5 and the second bevel gear 61 to rotate. When the spool 5 rotates, the upper end of the pull cable 9 can be wound onto or released from the spool 5. When the second bevel gear 61 rotates, the spring 7 is wound or released through the constantly meshing first spur gear 62 and second spur gear 63.

[0028] As a further improvement of the present invention, a mirror-symmetrical bearing seat 51 is fixedly installed on the partition plate 3. The two ends of the spool 5 are rotatably mounted on the bearing seat 51, and a first bevel gear 6 is fixedly connected to each end of the spool 5. The end of the pull wire 9 is wound around the middle of the spool 5 between the two first bevel gears 6. In this way, a set of spring-powered mechanisms connected to the first bevel gear 6 is provided at each end of the spool 5. The two sets of spring-powered mechanisms are symmetrically arranged and jointly drive the rotation of the spool 5, resulting in a more uniform and stable force distribution.

[0029] In addition, in order to improve the thermal conductivity between the encapsulation substrate 1 and the phase change material 2, a heat conduction fin 11 is provided on the inner wall of the encapsulation substrate 1 at the other end of the phase change material 2 away from the pressure plate 4.

[0030] The phase change material 2 used in this device is pre-cast in a mold and prepared into a cuboid or cylinder shape with a through hole 8 in the middle. The pre-prepared phase change material is placed into the encapsulation substrate 1, and a pull wire 9 passes through the pre-drilled through hole 8. Then, a pressure plate 4 and a spring-wound pull wire device are installed in sequence. One end of the pull wire 9 is tied to the pressure plate 4, and the other end is looped around the pulley 10 and tied to the reel 5. During production, after assembly, a special tool is used to rotate the first bevel gear 6 to store force in the spring 7. The force stored in the spring 7 is transmitted to the pressure plate 4 through the pull wire 9, thus causing the phase change material 2 to adhere tightly to the heat-conducting surface. However, since the phase change material 2 is solid at room temperature, the position of the pressure plate 4 will not move, and the force stored in the spring 7 will not be released. Finally, the top cover is closed when encapsulation is complete, thus completing the production process.

[0031] In use, the thermally conductive surface of the encapsulation substrate 1 is in direct contact with the heat dissipation surface of the heat-generating element. To avoid high contact thermal resistance, thermal grease can be applied to the contact surface. The heat generated by the electronic device is rapidly transferred to the thermally conductive surface through the thermal grease. Due to the high thermal conductivity of the copper or other metal materials used in the thermally conductive surface, the heat is quickly transferred to the phase change material 2 inside the encapsulation substrate 1. In the initial stage of heat dissipation, the heat is rapidly diffused throughout the entire thermal buffer through thermal conduction, and at this time, the heat is stored in the thermal buffer in the form of sensible heat. As heat is continuously absorbed, the temperature of the thermally conductive surface rises. When the temperature exceeds the melting point of the phase change material, the phase change material in close contact with the thermally conductive surface begins to melt, and the phase change endothermic process begins. When the phase change material at the contact surface melts, the spring 7 releases the stored elastic potential energy, and with the help of the pulley 10 and the pull line 9, it pulls the pressure plate 4, so that the solid phase change material that has not yet undergone phase change continues to adhere to the heat conduction surface, and the molten liquid phase change material is squeezed into the cavity vacated by the movement of the solid phase change material, so that the phase change heat absorption process is concentrated on the heat conduction surface and continues to effectively absorb the heat generated by electronic equipment.

[0032] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heat buffer for intensifying the melting endotherm of a phase change material by means of elastic potential energy, comprising an encapsulation matrix (1) and a phase change material (2) arranged in the encapsulation matrix (1), characterized in that The inside of the packaging base body (1) is fixedly installed with a partition plate (3) on one side of the phase change material (2), the partition plate (3) is provided with a pressing plate (4) on the side facing the phase change material (2), and a spring winding type pull wire device is arranged on the side away from the phase change material (2), the spring winding type pull wire device comprises a reel (5) winding a pull wire (9), a first bevel gear (6) fixedly installed on the reel (5), and a spring (7) in transmission connection with the first bevel gear (6); the center of the phase change material (2) is provided with a through hole (8), and a pulley (10) is arranged on the inner wall of the packaging base body (1) corresponding to the end of the through hole (8) away from the pressing plate (4); the pull wire (9) passes through the partition plate (3), the pressing plate (4) and the through hole (8), bypasses the pulley (10), and the terminal end is fixedly connected to the pressing plate (4).

2. The thermal buffer of claim 1, wherein: the thermal buffer is configured to store the elastic potential energy in the spring when the thermal buffer is in the first state; and the thermal buffer is configured to release the elastic potential energy from the spring to the phase change material when the thermal buffer is in the second state. The spring (7) is wound on the gear shaft of a second bevel gear (61), and the second bevel gear (61) is always engaged with the first bevel gear (6).

3. The thermal buffer of claim 1 or 2, wherein: the thermal buffer is configured to store the elastic potential energy in the spring when the thermal buffer is in the first state; and the thermal buffer is configured to release the elastic potential energy from the spring to the phase change material when the thermal buffer is in the second state. The partition plate (3) is fixedly installed with an axle seat (51), and the reel (5) is rotatably installed on the axle seat (51).

4. The thermal buffer of claim 1, wherein: the thermal buffer is configured to store the elastic potential energy in the spring when the thermal buffer is in the first state. The second bevel gear (61) is fixedly installed with a coaxially arranged first spur gear (62), the spring (7) is wound on the gear shaft of a second spur gear (63), and the second spur gear (63) is always engaged with the first spur gear (62).

5. The thermal buffer of claim 1 or 4, wherein: the thermal buffer is configured to store the elastic potential energy in the spring when the thermal buffer is in the first state; and the thermal buffer is configured to release the elastic potential energy from the spring to the phase change material when the thermal buffer is in the second state. The partition plate (3) is fixedly installed with a mirror-symmetrical axle seat (51), both ends of the reel (5) are rotatably installed on the axle seat (51), and each of the two ends of the reel (5) is fixedly connected with a first bevel gear (6); the end of the pull wire (9) is wound on the middle part of the reel (5) between the two first bevel gears (6).

6. The thermal buffer of claim 3, wherein: The axle seat (51) is a mirror-symmetrical structure, and both ends of the reel (5) are rotatably installed on the axle seat (51).

7. The thermal buffer of claim 1 or 4, wherein: the thermal buffer is configured to store the elastic potential energy in the spring when the thermal buffer is in the first state. A heat conduction fin (11) is arranged on the inner wall of the packaging base body (1) corresponding to the other end of the phase change material (2) away from the pressing plate (4).

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