Two-phase heat dissipation system

Abstract

The invention discloses a two-phase heat dissipation system, and relates to the technical field of heat dissipation of electronic components, the two-phase heat dissipation system comprises a heat pipe shell and a microfluidic assembly, the first end of the heat pipe shell is a condensation pipe section, the second end of the heat pipe shell is an evaporation pipe section, and a transportation pipe section is arranged between the condensation pipe section and the evaporation pipe section. The micro-fluidic assembly comprises a transportation section chip arranged on the transportation pipe section, the transportation section chip serves as a power source for transportation of the liquid heat exchange working medium and is used for conveying condensed liquid drops of the heat exchange working medium in the direction from the condensation pipe section to the evaporation pipe section, and the transportation pipe section and the transportation section chip are both made of bendable flexible materials. According to the two-phase heat dissipation system disclosed by the invention, the microfluidic technology and the heat pipe structure are combined, and the transportation pipe section and the transportation section chip are prepared through the flexible material, so that the two-phase heat dissipation system disclosed by the invention can be applied to a complex heat transfer path in which a cold source and a heat source are not on the same plane; and the situation that large performance loss occurs after a conventional heat pipe is bent is avoided, and machining is convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of electronic components, and more specifically, to a two-phase heat dissipation system. Background Art

[0002] With the development of new technologies such as cloud computing, big data, and 5G communication, the integration and computing speed of electronic chips have been continuously improved. Correspondingly, the high heat generated by high energy consumption will reduce the reliability of electronic components. Therefore, the efficient heat dissipation of electronic components has become an increasingly prominent problem at present. For heat-generating devices with high heat flux density, the current mainstream heat dissipation methods are forced air cooling or water cooling. A heat pipe is the main device for heat exchange between the heat source and the cold medium in a forced air cooling heat dissipation module.

[0003] When a conventional heat pipe with a rigid outer shell is dealing with a complex heat transfer path, it needs to complete the bending of the target shape through steps such as mold opening, bending, hot pressing, and cold pressing. The processing procedure is complex, and at the same time, the heat transfer performance is severely lost after bending. The performance of a conventional heat pipe is mainly determined by its capillary structure characteristics. When dealing with application scenarios of long-distance transportation and anti-gravity (that is, in the vertical direction, the cold source is below the heat source), there are defects such as insufficient return transportation volume and uncontrollable transportation volume of the heat transfer working medium. Therefore, in order to break through the limitation of the capillary limit, loop heat pipes and other heat pipes that can achieve anti-gravity and long-distance transportation have emerged, but loop heat pipes have start-up problems and stability problems. The prior art mainly includes two active temperature control systems. One is to use a micro pressure point actuated fluid pump to control the fluid flow, and the other is to use dielectrophoretic force to drive the movement of droplets. However, the active temperature control system uses single-phase heat transfer, which is difficult to meet the heat dissipation scenario of high heat flux density, and at the same time has defects such as large space occupation and low integration.

[0004] Therefore, how to achieve efficient heat dissipation of electronic components in complex installation scenarios has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a two-phase heat dissipation system to achieve efficient heat dissipation of electronic components in complex installation scenarios.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A two-phase heat dissipation system, comprising:

[0008] A heat pipe housing, the first end of the heat pipe housing is a condensation pipe section, the second end is an evaporation pipe section, a transportation pipe section is arranged between the condensation pipe section and the evaporation pipe section, and the transportation pipe section is made of a bendable flexible material;

[0009] The microfluidic component includes a transport section chip disposed on the transport pipe section. The transport section chip is configured to transport the liquid heat transfer working medium from the condensation pipe section towards the evaporation pipe section, and the transport section chip is made of a bendable flexible material.

[0010] Optionally, in the above two-phase heat dissipation system, a protection component is further included. The protection component is disposed on the transport pipe section and is used to limit the maximum bending angle of the transport pipe section.

[0011] Optionally, in the above two-phase heat dissipation system, the protection component includes a plurality of protection shells. The protection shells are sequentially sleeved outside the transport pipe section along the direction from the condensation pipe section to the evaporation pipe section, are arranged at intervals, and adjacent two protection shells are bendably connected through a connection component.

[0012] Optionally, in the above two-phase heat dissipation system, the connection component includes:

[0013] An elastic member, which is made of an elastic material and is disposed between adjacent two protection shells;

[0014] A fixing member, and the end of the elastic member is connected to the protection shell through the fixing member.

[0015] Optionally, in the above two-phase heat dissipation system, the connection component includes:

[0016] A hinge seat, which is disposed at one end of the protection shells close to each other and is provided with a first hinge hole;

[0017] A connecting member, which is disposed between adjacent two protection shells and is provided with a second hinge hole corresponding to the first hinge hole, and a hinge shaft passes through the first hinge hole and the second hinge hole.

[0018] Optionally, in the above two-phase heat dissipation system, an installation opening is provided on the evaporation pipe section, an evaporation bottom plate is disposed at the installation opening, and a capillary core or a hydrophilic coating is provided on the evaporation bottom plate.

[0019] Optionally, in the above two-phase heat dissipation system, a condensation section chip is disposed on the condensation pipe section, and the condensation section chip is connected to the transport section chip.

[0020] Optionally, in the above two-phase heat dissipation system, along the direction from the condensation pipe section to the evaporation pipe section, a first electrode and a second electrode are sequentially disposed on the condensation section chip, and a transport section electrode is disposed on the transport section chip;

[0021] The size of the second electrode is smaller than the size of the first electrode and larger than the size of the transport section electrode.

[0022] Optionally, in the above two-phase heat dissipation system, the extension length of the condensation tube section is at least three times that of the evaporation tube section.

[0023] Optionally, in the above two-phase heat dissipation system, the microfluidic component includes a control member for controlling the energization sequence of the transport section electrodes on the transport section chip;

[0024] The control member and the transport section chip are of an integral structure, or the control member is connected to the transport section chip through a flexible wiring assembly.

[0025] The two-phase heat dissipation system provided by the present invention includes a heat pipe housing and a microfluidic component. The first end of the heat pipe housing is a condensation tube section, and the second end is an evaporation tube section. The condensation tube section is used for heat exchange with a cold source, and the evaporation tube section is used for heat exchange with a heat source. A transport tube section is arranged between the condensation tube section and the evaporation tube section. The transport tube section is used for allowing a heat exchange working medium to flow between the condensation tube section and the evaporation tube section. The transport tube section is made of a bendable flexible material. The microfluidic component includes a transport section chip arranged on the transport tube section. The transport section chip serves as the power source for transporting the liquid heat exchange working medium and is used for transporting the condensed droplets of the heat exchange working medium from the condensation tube section to the evaporation tube section direction without additionally setting an external power member or generating power through the pressure difference in the flow channel, making the space of the two-phase heat dissipation system more compact, the complexity of the system lower, and the reliability better. And the transport section chip is also made of a bendable flexible material to bend along with the bending of the transport tube section.

[0026] During the operation of the two-phase heat dissipation system, the evaporation tube section is arranged in the target area to be cooled, and absorbs the heat of the heat source to make the liquid heat exchange working medium at the evaporation tube section absorb heat and become a gaseous heat exchange working medium. Then, the gaseous heat exchange working medium flows from the transport tube section to the condensation tube section and exchanges heat with a cold source such as air cooling, water cooling, and semiconductor refrigeration through the heat pipe housing of the condensation tube section, so that the gaseous heat exchange working medium is re-liquefied into a liquid heat exchange working medium. The condensed droplets of the liquid heat exchange working medium are transported by the transport section chip along the transport tube section back to the evaporation tube section to complete a working cycle of the two-phase heat dissipation system.

[0027] Compared with the prior art, the two-phase cooling system provided by the present invention combines microfluidic technology and a heat pipe structure, and transfers heat through the phase change method. It has a larger liquid working medium transportation volume, anti-gravity ability, long-distance transportation ability, and a larger Qmax (peak value of heat transfer) compared with conventional heat pipes, and can be applied to the heat dissipation scenario with high heat flux density in electronic heat dissipation. At the same time, by adjusting the control parameters of the microfluidic component, the flow rate of the liquid heat exchange working medium can be accurately controlled, so that the two-phase cooling system can maintain the best working efficiency under different working conditions, and has better start-up response and working stability. The two-phase cooling system provided by the present invention integrates the microfluidic component on the heat pipe housing, and the microfluidic component only functions to transport the liquid working medium and does not function as heat conduction, and has a smaller thermal resistance compared with the prior art solution that directly uses a microfluidic chip for heat conduction. And through the transportation pipe section and transportation section chip prepared by flexible materials, the two-phase cooling system provided by the present invention can be applied to complex heat transfer paths where the cold source and the heat source are not in the same plane, and avoids large performance losses after conventional heat pipes are bent, omitting processes such as mold opening, bending, cold pressing, and hot pressing in the conventional heat pipe bending process, and improving the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic diagram of the working principle of the two-phase cooling system disclosed in the embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram of the overall structure of the two-phase cooling system disclosed in the embodiment of the present invention;

[0031] Figure 3 It is an exploded view of the two-phase cooling system disclosed in the embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the structure of the first two-phase cooling system disclosed in the embodiment of the present invention;

[0033] Figure 5 It is a top view of the two-phase cooling system disclosed in the embodiment of the present invention;

[0034] Figure 6 It is a front view of the two-phase cooling system disclosed in the embodiment of the present invention;

[0035] Figure 7 It is an exploded view of the evaporation pipe section of the two-phase cooling system disclosed in the embodiment of the present invention;

[0036] Figure 8 Isometric view of the first protection component disclosed in the embodiments of the present invention;

[0037] Figure 9 Front view of the first protection component disclosed in the embodiments of the present invention Figure 1 ;

[0038] Figure 10 Front view of the first protection component disclosed in the embodiments of the present invention Figure 2 ;

[0039] Figure 11 Top view of the second protection component disclosed in the embodiments of the present invention;

[0040] Figure 12 Front view of the second protection component disclosed in the embodiments of the present invention;

[0041] Figure 13 Exploded view of the second protection component disclosed in the embodiments of the present invention;

[0042] Figure 14 Schematic structural diagram of the second two-phase heat dissipation system disclosed in the embodiments of the present invention;

[0043] Figure 15 Schematic structural diagram of the transportation structure of the transportation section chip disclosed in the embodiments of the present invention.

[0044] Among them, 1 is the condensing pipe section, 2 is the transportation pipe section, 3 is the evaporation pipe section, 4 is the condensing section electrode, 5 is the transportation section electrode, 6 is the large liquid droplet, 7 is the small liquid droplet, 8 is the liquid filling port, 9 is the control part, 10 is the wiring harness, 11 is the cold source, 12 is the heat source, 13 is the FPC connector, 14 is the protective housing, 15 is the capillary core, 16 is the heat pipe housing, 17 is the elastic part, 18 is the fixing part, 19 is the connecting part, 20 is the hinge seat, 21 is the hinge shaft, 22 is the substrate, 23 is the dielectric layer, 24 is the hydrophobic layer, 25 is the evaporation bottom plate, 26 is the condensing section chip, and 27 is the transportation section chip. Detailed implementation manners

[0045] The core of the present invention lies in disclosing a two-phase heat dissipation system to achieve efficient heat dissipation of electronic components in complex installation scenarios.

[0046] Hereinafter, embodiments will be described with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the inventive concept described in the claims in any way. Furthermore, all the contents of the configurations shown in the following embodiments are not necessarily essential for the solution of the invention described in the claims. It should be noted that, for ease of description, only parts related to the relevant invention are shown in the drawings. Without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0047] Combined with Figure 2 and Figure 3 , the two-phase heat dissipation system disclosed in the embodiments of the present invention includes a heat pipe housing 16 and a microfluidic component. The first end of the heat pipe housing 16 is a condensation pipe section 1, and the second end is an evaporation pipe section 3. The condensation pipe section 1 is used to exchange heat with a cold source 11, and the evaporation pipe section is used to exchange heat with a heat source 12. A transport pipe section 2 is provided between the condensation pipe section 1 and the evaporation pipe section 3, and the transport pipe section 2 is used for the heat transfer working fluid to flow between the condensation pipe section 1 and the evaporation pipe section 3. Since the condensation pipe section 1 is generally used for rigid fixation with the cold source 11, and the evaporation pipe section 3 is generally used for rigid fixation with the heat source 12, the extension length where the transport pipe section 2 is located is usually the part where the heat pipe housing 16 needs to be bent. Therefore, the transport pipe section 2 is made of a bendable flexible material, and the materials of the condensation pipe section 1 and the evaporation pipe section 3 can be the same as or different from that of the transport pipe section 2. To ensure the heat dissipation effect, the parts of the condensation pipe section 1 and the condensation pipe section 1 respectively used for fixation with the cold source 11 and the heat source 12 are usually made of a metal material with stronger thermal conductivity to reduce the thermal resistance.

[0048] The microfluidic component includes a transport section chip 27 provided on the transport pipe section 2. Combined with Figure 4 , both ends of the transport section chip 27 extend to the condensation pipe section 1 and the evaporation pipe section 3 respectively. The transport section chip 27 serves as the power source for transporting the liquid heat transfer working fluid, and is used to transport the condensed droplets of the heat transfer working fluid from the condensation pipe section 1 to the evaporation pipe section 3 direction, without the need to additionally provide an external power component or generate power through the pressure difference in the flow channel, making the space of the two-phase heat dissipation system more compact, the complexity of the system lower, and the reliability better. And the transport section chip 27 is also made of a bendable flexible material to bend along with the bending of the transport pipe section 2.

[0049] During the operation of the two-phase heat dissipation system, the evaporation pipe section 3 is arranged in the target area to be cooled, and absorbs the heat of the heat source 12 to make the liquid heat transfer working fluid at the evaporation pipe section 3 absorb heat and become a gaseous heat transfer working fluid. Then, the gaseous heat transfer working fluid flows from the transport pipe section 2 to the condensation pipe section 1, and exchanges heat with the cold source 11 such as air cooling, water cooling, and semiconductor refrigeration through the heat pipe housing 16 of the condensation pipe section 1, so that the gaseous heat transfer working fluid is re-liquefied into a liquid heat transfer working fluid. The condensed droplets of the liquid heat transfer working fluid are transported back to the evaporation pipe section 3 along the transport pipe section 2 by the transport section chip 27, completing one working cycle of the two-phase heat dissipation system.

[0050] Compared with the prior art, the two-phase cooling system disclosed in the embodiments of the present invention combines microfluidic technology and a heat pipe structure, and transfers heat through the phase change method. It has a larger liquid working medium transportation volume, anti-gravity ability, long-distance transportation ability, and a larger Qmax (peak value of heat transfer) compared with conventional heat pipes, and can be applied to the heat dissipation scenario with high heat flux density in electronic heat dissipation; at the same time, by adjusting the control parameters of the microfluidic component, the flow rate of the liquid heat exchange working medium can be accurately controlled, so that the two-phase cooling system can maintain the best working efficiency under different working conditions, and has better start-up response and working stability; the two-phase cooling system disclosed in the embodiments of the present invention integrates the microfluidic component on the heat pipe housing 16, and the microfluidic component only functions to transport the liquid working medium and does not function as heat conduction, and has a smaller thermal resistance compared with the prior art solution that directly uses a microfluidic chip for heat conduction; and through the transportation pipe section 2 and the transportation section chip 27 prepared by flexible materials, the two-phase cooling system disclosed in the embodiments of the present invention can be applied to complex heat transfer paths where the cold source 11 and the heat source 12 are not in the same plane, and avoids the large performance loss after the conventional heat pipe is bent, omitting the processes such as mold opening, bending, cold pressing, and hot pressing in the conventional heat pipe bending process, and improving the processing efficiency.

[0051] Specifically, the substrate 22 of the transportation section chip 27 can be prepared from flexible PCB materials such as cyclic olefin polymer film (COP) and polydimethylsiloxane film (PDMS), and the transportation pipe section 2 can be prepared from organic polymer flexible materials such as silicone rubber and soft rubber materials. The transportation section chip 27 can be welded or adhered to the surface of the inner cavity of the transportation pipe section 2 of the heat pipe housing 16. The heat pipe housing 16 can also be integrally prepared from shape memory alloy, which has better sealing performance and lower thermal resistance compared with the heat pipe housing 16 prepared from organic polymer flexible materials.

[0052] In order to avoid large wrinkles and collapses on the inner wall of the transportation pipe section 2 during the bending process due to excessive bending angle of the heat pipe housing 16, increasing the flow resistance, a protection component is provided outside the transportation pipe section 2, and the protection component is used to limit the maximum bending angle of the transportation pipe section 2.

[0053] Specifically, the protection component includes a plurality of protection shells 14. Along the direction from the condensation pipe section 1 to the evaporation pipe section 3, each protection shell 14 is sequentially sleeved outside the transportation pipe section 2, and each protection shell 14 is arranged at intervals and is bendably connected between two protection shells 14 through a connection component, and the connection component can adapt to the angle change between adjacent two protection shells 14. The protection shell 14 is prepared from a hard material such as metal, and can provide support for the flexible transportation pipe section 2, thereby preventing local collapse and damage from occurring during the bending process of the heat pipe housing 16.

[0054] A gap is reserved between two adjacent protective housings 14 to allow the protective housing 14 to adapt to the bending deformation of the transport pipe section 2. By designing the size of the protective housing 14 and the spacing distance between the protective housings 14, the maximum bending angle of the transport pipe section 2 can be controlled. According to the actual application scenario, generally, it is only necessary to ensure that the maximum bending angle of the transport pipe section 2 does not exceed 45° to meet the conventional use requirements.

[0055] Combined with Figure 3 , the cross-section of the protective housing 14 is a rectangle corresponding to the heat pipe housing 16. By reasonably designing the size of the protective housing 14 to make the protective housing 14 have an interference fit with the heat pipe housing 16, the protective housing 14 can be tightly sleeved outside the transport pipe section 2 without slipping off; the protective housing 14 and the transport pipe section 2 can also be fixed by bonding or other means. Specifically, each protective housing 14 can be bonded and fixed to the transport pipe section 2, or only several protective housings 14 can be bonded and fixed to the transport pipe section 2.

[0056] Combined with Figure 8 and Figure 9 , in the circumferential direction, the connection assembly can be arranged only on two opposite side surfaces of the protective housing 14 to achieve connection.

[0057] In one embodiment, the connection assembly includes an elastic member 17 and a fixing member 18. The elastic member 17 is made of an elastic material such as silicone rubber, and the elastic member 17 is arranged between two adjacent protective housings 14. The fixing member 18 is used to fix the end of the elastic member 17 to the protective housing 14. During the bending process of the protective component with the transport pipe section 2, the elastic member 17 deforms accordingly to adapt to the change of the connection angle between different protective housings 14.

[0058] Specifically, combined with Figures 8 - 10 , the elastic member 17 can be an elastic rubber sheet with a rectangular sheet structure, and the fixing member 18 can be a buckle (as shown in Figure 9 , a clamping protrusion corresponding to the card slot of the buckle is arranged at the end of the elastic member 17), a rivet or other structural members that can fix the elastic member 17 to the protective housing 14. The fixing member 18 and the protective housing 14 can be installed and fixed by CNC or welding or other means.

[0059] In another embodiment, combined with Figures 11 - 13, the connecting component includes a hinge seat 20 and a connecting piece 19. The hinge seat 20 is made of a rigid material, and the connecting piece 19 can be made of a rigid material or a flexible material such as silicone rubber. Among them, the hinge seat 20 is arranged at one end of each protective housing 14 close to each other, and a first hinge hole is formed in the hinge seat 20. The connecting piece 19 is arranged between the hinge seats 20 of two adjacent protective housings 14 and is provided with a second hinge hole corresponding to the first hinge hole. A hinge shaft 21 passes through the first hinge hole and the second hinge hole to realize the hinge connection between the protective housing 14 and the connecting piece 19, so that the protective housing 14 as a whole forms a mechanical hinge structure.

[0060] Among them, the hinge seat 20 can be a protruding structural ring on the protective housing 14. The hinge shaft 21 is provided correspondingly and includes a first hinge part and a second hinge part. A first limit protrusion is arranged at the first end of the first hinge part, and the second end passes through the first hinge hole and the second hinge hole. A second limit protrusion is arranged at the first end of the second hinge part, and the second end is used for screwing into the second end of the first hinge part. The cooperation of the first limit protrusion and the second limit protrusion makes the hinge shaft 21 unable to break away from the hinge position of the connecting piece 19 and the hinge seat 20.

[0061] Compared with the connecting component made of an elastic material such as silicone rubber, the connecting component made of a rigid material has higher structural strength and longer service life.

[0062] In order to further improve the transportation effect of the liquid heat exchange working medium, a condensation section chip 26 is arranged on the condensation pipe section 1, and the condensation section chip 26 is connected to the transportation section chip 27.

[0063] When the gaseous heat exchange working medium condenses into liquid droplets in the condensation pipe section 1, the condensation section chip 26 can quickly transport the condensed liquid droplets to the transportation section chip 27 and be quickly transported by the transportation section chip 27 to the evaporation pipe section 3. During the operation of the two-phase heat dissipation system, there is a continuous current circulation on the microfluidic electrodes located on the transportation section chip 27 and the condensation section chip 26, which can realize the continuous transportation of the condensed liquid droplets and ensure the cyclic operation of the two-phase heat dissipation system.

[0064] The shapes, sizes and numbers of the microfluidic electrodes on the microfluidic component (including the condensation section electrode 4 on the condensation section chip 26 and the transportation section electrode 5 on the transportation section chip 27) can be designed according to the types and transportation amounts of the heat exchange working media. By designing the microfluidic electrodes and controlling the voltage, the transportation section chip 27 and the condensation section chip 26 can have stronger transportation ability and anti-gravity ability for the liquid heat exchange working medium.

[0065] Along the direction from the condensation tube section 1 to the evaporation tube section 3, the shapes of the various microfluidic electrodes can be the same or different. The shapes of the microfluidic electrodes can be square, circular, curved quadrilateral, crescent, cross, etc. Different microfluidic electrode shapes have different functions. The square microfluidic electrodes are simple to arrange and easy to process, but droplets will be retained during the transportation of droplets; the crescent-shaped microfluidic electrodes have the advantage of unidirectional rapid drive; the circular microfluidic electrodes are usually used in combination with the bidirectional crescent-shaped microfluidic electrodes to achieve bidirectional rapid transportation; the cross-shaped microfluidic electrodes also have the function of bidirectional rapid transportation.

[0066] The larger the size of the microfluidic electrode, the larger the size of the droplets that can be driven; for the same microfluidic electrode, the greater the voltage applied, the more dramatic the change in the surface tension of the condensed droplets at the moment of power-on, and the greater the acceleration of its movement. The size and movement speed of the condensed droplets can be controlled by adjusting the voltage and interval time. The method of using electric field to control the movement of condensed droplets has the advantage of rapid response, which can ensure that the microfluidic component immediately enters the best working state after power is turned on.

[0067] Along the direction from the condensation pipe section 1 to the evaporation pipe section 3, the microfluidic electrodes can be arranged in one row or in multiple rows parallel to each other, which can be designed according to the requirements of installation space and transportation volume.

[0068] In a specific embodiment disclosed in the present invention, it is defined that in the direction from the condensation pipe section 1 to the evaporation pipe section 3, the condensation section electrode 4 on the condensation section chip 26 is successively the first electrode and the second electrode, and the size of the second electrode is smaller than the size of the first electrode, and larger than the size of the transport section electrode 5.

[0069] The first electrode is used to drag the randomly distributed condensed droplets in the condensation pipe section 1 to the location of the transport section chip 27, and gather them into large droplets 6 of larger volume to ensure the reserve of liquid heat exchange medium. The second electrode can gradually pull the large droplets 6 of larger volume gathered in the condensation pipe section 1 into small droplets 7 of smaller volume to increase the transportation speed of single condensed droplets, and transport them to the junction of the condensation pipe section 1 and the transport pipe section 2. The transport section chip 27 is used to continuously transport the small droplets 7 to the evaporation pipe section 3 through the transport pipe section 2.

[0070] The condensation section electrode 4 can be arranged at the middle position of the condensation section chip 26 , and the condensation section chip 26 can be arranged at the middle position of the condensation pipe section 1 to ensure the transport performance of the condensation droplets gathered at the condensation pipe section 1 .

[0071] The microfluidic component includes a control member 9 which is used to supply power to the transport section electrodes 5 on the transport section chip 27 and control the intensity and timing of the energization. Specifically, the control member 9 and the transport section chip 27 can be of an integral structure, or the control member 9 can be connected to the transport section chip 27 through a flexible wiring assembly.

[0072] Electrode interfaces are provided on the transport section chip 27. In combination with Figure 4 and Figure 5 , in one embodiment, the control member 9 is flexibly connected to the electrode interfaces of the transport section chip 27 through an FPC connector 13 and a cable 10, which is applicable to the installation scenario where the control member 9 and the heat pipe housing 16 are not in the same plane or are at a relatively long distance. Correspondingly, a wiring avoidance opening for avoiding wiring at the electrode interface is provided on the heat pipe housing 16.

[0073] Furthermore, when the size of the heat pipe housing 16 is relatively large, the electronic components on the control member 9 can be integrated on the outer wall of the condensation pipe section 1 opposite to the cold source 11, and only a power interface needs to be reserved for external connection, so as to further improve the space utilization rate.

[0074] In combination with Figure 14 , the control member 9 is an integral structure integrated with the transport section chip 27 to improve the space utilization rate. According to the actual size of the heat pipe housing 16, the control member 9 can be arranged inside the heat pipe housing 16, and only a power interface is reserved to be connected to the power supply outside the heat pipe housing 16 through the wiring avoidance opening of the heat pipe housing 16.

[0075] In order to avoid the wiring of the transport section electrodes 5 affecting its transport function, the transport section chip 27 is a multi-layer PCB structure, so that the transport section electrodes 5 and the electrode interfaces can be arranged on different layers of the PCB structure.

[0076] In a specific embodiment disclosed by the present invention, the transport section chip 27 is a three-layer PCB board structure. The transport section electrodes 5 are printed on the first layer of the PCB board close to the inside of the heat pipe housing 16, the electrode interfaces are arranged on the third layer of the PCB board far from the inside of the heat pipe housing 16, and the wiring structure of the transport section electrodes 5 is arranged on the second layer of the PCB board located between the first layer of the PCB board and the second layer of the PCB board.

[0077] The structure of the condensation section chip 26 is the same as that of the transport section chip 27, and it is also a multi-layer PCB structure. In one embodiment, the control member 9 is connected to the condensation section chip 26, and the transport section chip 27 and the condensation section chip 26 are docked through an interface in the cross-sectional direction. The transport section chip 27 receives a current signal from the condensation section chip 26, that is, only one control member 9 can be provided.

[0078] The condensation section chip 26 and the transport section chip 27 can also be of an integral structure and be controlled by the same control member 9.

[0079] Combined with Figure 15 , a dielectric layer 23 is sprayed on the surfaces of the transport section electrode 5 and the condensation section electrode 4 to prevent the electrolysis of the heat transfer working fluid caused by the direct contact between the transport section electrode 5 and the heat transfer working fluid. The material of the dielectric layer 23 can be a variety of materials such as polydimethylsiloxane film (PDMS).

[0080] Furthermore, a hydrophobic layer 24 can be provided on the outer layer of the dielectric layer 23 to increase the contact angle of the condensate droplets and facilitate the generation of the dielectric wetting force on the microfluidic electrode.

[0081] To facilitate the convergence of the condensate droplets in the condensate tube section 1, a hydrophilic layer is provided at a position on the condensate section chip 26 other than the condensate section electrode 4 to facilitate the aggregation of the condensate droplets falling from the condensate tube section 1 on the condensate section chip 26.

[0082] Correspondingly, the inner wall of the condensate tube section 1 of the heat pipe housing 16 is treated with hydrophobic treatment through processes such as spin coating and spraying to promote the condensate droplets to more easily fall on the condensate section chip 26.

[0083] Combined with Figure 4 , converging slopes are provided on both sides of the condensate section chip 26 along the extending direction to facilitate the droplets on both sides of the condensate section chip 26 to more easily flow along the converging slopes to the middle position of the condensate section chip 26, facilitating the transport of the condensate section electrode 4.

[0084] Furthermore, a blocking member is provided on the transport pipe section 2 to isolate the gaseous heat transfer working fluid from the liquid heat transfer working fluid, so that the transport of the gaseous heat transfer working fluid and the liquid heat transfer working fluid does not affect each other. Furthermore, the impact of the high-speed flowing gaseous heat transfer working fluid on the transport of the liquid heat transfer working fluid can be avoided, and at the same time, the heating effect of the gaseous heat transfer working fluid on the liquid heat transfer working fluid can be reduced.

[0085] Specifically, the blocking member can be a baffle provided on both sides of the transport section electrode 5 on the transport section chip 27, or a steam pipe that only allows the gaseous heat transfer working fluid to pass through can be installed in the transport pipe section 2, and the gaseous heat transfer working fluid and the transport section electrode 5 are isolated through the steam pipe to achieve the mutual isolation of the gaseous heat transfer working fluid and the liquid heat transfer working fluid.

[0086] In a specific embodiment disclosed in the present invention, the heat pipe shell 16 is a long strip structure, and a mounting groove is provided on one side wall of the heat pipe shell 16, the mounting groove is arranged along the extension direction of the heat pipe shell 16, and a condensation section chip 26, a transport section chip 27 and an evaporation base plate 25 are sequentially arranged on the mounting groove, and the two ends of the transport section chip 27 are respectively connected to the condensation section chip 26 and the evaporation base plate 25, the condensation section chip 26 and the condensation pipe section 1 of the heat pipe shell 16 constitute a condensation cavity, the transport section chip 27 and the transport pipe section 2 of the heat pipe shell 16 constitute a transport cavity, the evaporation base plate 25 is used for contact and heat exchange with the heat source 12, and the evaporation base plate 25 and the evaporation pipe section 3 of the heat pipe shell 16 constitute an evaporation cavity.

[0087] The evaporation base plate 25 may be a block structure made of the same material as the heat pipe shell 16, so as to facilitate welding and fixing with the heat pipe shell 16. The evaporation base plate 25 may be made of metal materials such as copper and aluminum.

[0088] Combination Figure 4 Both sides of the condensing section chip 26 and the transport section chip 27 along the extension direction are provided with positioning steps for being embedded and matched with the mounting groove of the heat pipe shell 16.

[0089] In another embodiment disclosed in the present invention, Figure 7 The evaporation pipe section 3 of the heat pipe shell 16 is provided with an installation opening, the evaporation base plate 25 is arranged on the evaporation pipe section 3 through the installation opening, and the capillary wick 15 is arranged on one side of the evaporation base plate 25 located inside the heat pipe shell 16. The condensation section chip 26 and the transport section chip 27 are respectively arranged on the inner walls of the condensation pipe section 1 and the transport pipe section 2 of the heat pipe shell 16.

[0090] The capillary core 15 can store and evenly distribute the liquid heat exchange medium. At the same time, the capillary core 15 can enhance boiling and prevent the liquid heat exchange medium from drying up, causing a sharp rise in temperature at the heat source 12 and causing damage to electronic components. Figure 1 After reaching the evaporation pipe section 3 in the direction of the solid arrow, it quickly spreads in the capillary structure inside the capillary wick 15. The heat of the heat source 12 contacted by the evaporation pipe section 3 reaches the capillary wick 15 through the evaporation bottom plate 25 through heat conduction. The condensed liquid droplets in the capillary wick 15 absorb heat and change phase. The vapor overflows from the capillary wick 15 and then flows along the transport pipe section 2 ( Figure 1 The condenser moves toward the condenser pipe section 1 (in the direction of the dashed arrow).

[0091] The capillary core 15 can be a capillary structure formed by sintered copper powder, sintered copper mesh, metal 3D printing, electrodeposition, or a porous structure formed by laser engraving, wire cutting, CNC or other mechanical processing directly on a metal block. The shape of the mounting port corresponds to the shape of the evaporation base plate 25, and is generally rectangular for ease of assembly.

[0092] Preferably, the capillary wick 15, the evaporation bottom plate 25, and the heat pipe housing 16 are made of the same material to ensure the firmness of the sintering between the capillary wick 15 and the evaporation bottom plate 25, and the reliability of the welding between the evaporation bottom plate 25 and the heat pipe housing 16.

[0093] During assembly, first place the transport section chip 27 and the steam pipe in the heat pipe housing 16, then combine the capillary wick 15 and the evaporation bottom plate 25 together by sintering, welding, or bonding, etc., and finally weld the evaporation bottom plate 25 and the heat pipe housing 16 together. Figure 7 Moreover, at one end of the evaporation bottom plate 25, there is a sealing plate that can seal the end of the heat pipe housing 16.

[0094] In one embodiment, the transport section chip 27, the steam pipe, and the capillary wick 15 are sequentially arranged in the heat pipe housing 16 through the opening at one end of the heat pipe housing 16, and finally the heat pipe housing 16 is sealed with an end cap, thus completing the assembly of the two-phase heat dissipation system.

[0095] In some low heat flux / low power heat source scenarios, by coating a hydrophilic layer above the evaporation bottom plate 25, the droplets transported by the transport pipe section 2 can also be quickly spread by means of the hydrophilicity of the hydrophilic layer, increasing the evaporation area and performing boiling heat transfer, as long as it can be ensured that the amount of phase change heat absorption of the liquid heat transfer working medium in the evaporation pipe section 3 is not less than the heat at the heat source 12, so that the heat source 12 can be maintained within the target temperature range.

[0096] When designing the structure of the two-phase heat dissipation system, the structure on the evaporation bottom plate 25 can be selected according to factors such as cost and processing difficulty.

[0097] To improve the heat conduction effect, a heat conductive agent such as heat conductive silicone grease is coated at the position where the condensation pipe section 1 contacts the cold source 11, and a heat conductive agent such as heat conductive silicone grease is coated at the position where the evaporation bottom plate 25 contacts the heat source 12. The condensation pipe section 1 and the evaporation bottom plate 25 can also be directly welded to the cold source 11 and the heat source 12 respectively.

[0098] To ensure sufficient heat dissipation effect, the extended length of the condensation pipe section 1 is at least three times that of the evaporation pipe section 3, so as to improve the heat transfer efficiency by increasing the size ratio of the condensation pipe section 1.

[0099] Specifically, according to the different structures of the cold source 11, the extended length of the condensation pipe section 1 is different. Compared with the heat dissipation scheme where the cold source 11 is an air-cooling device, the heat dissipation effect is better when the cold source 11 is a liquid-cooling device, and the extended length of the condensation pipe section 1 can be set shorter. The transport capacity of the two-phase heat dissipation system for the liquid heat transfer working medium disclosed in the embodiments of the present invention is not limited by the length. Therefore, the overall length of the two-phase heat dissipation system can be adjusted according to the actual working conditions.

[0100] It should be noted that, generally, along the extending direction of the heat pipe housing 16, the height of the transport pipe section 2 (the distance between the surface of the heat pipe housing 16 facing the transport section chip 27 and the transport section chip 27) is comparable to the diameter of the condensate droplet; while the width of the heat pipe housing 16 (the distance between two opposite side walls of the heat pipe housing 16) needs to be much wider than the diameter of the droplet.

[0101] In one embodiment, a liquid filling port 8 for liquid filling is provided on the heat pipe housing 16. Combining Figure 6 , the liquid filling port 8 can be sealed and fixed at the end of the condensate pipe section 1 or the evaporation pipe section 3 of the heat pipe housing 16 by means of welding, gluing, etc. The liquid filling port 8 can also be directly prepared by processing the end of the heat pipe housing 16 in the way of a shrinkable hose. After one-time liquid filling is completed, the liquid filling port 8 is welded and sealed.

[0102] After the heat transfer working fluid is injected into the two-phase heat dissipation system through the liquid filling port 8, the liquid heat transfer working fluid accumulates in the condensate pipe section 1. When power is supplied to the condensate section chip 26 and the transport section chip 27, the two-phase heat dissipation system enters the working state. By sequentially applying power to the microfluidic electrodes arranged on the condensate section chip 26 and the transport section chip 27 in the direction from the condensate pipe section 1 to the evaporation pipe section 3 in a cycle, the droplets are continuously transported from the condensate pipe section 1 to the evaporation pipe section 3.

[0103] In another embodiment, a fluorine injection nozzle is welded on the heat pipe housing 16. The fluorine injection nozzle is used to adjust the liquid filling amount in the two-phase heat dissipation system. The body of the fluorine injection nozzle is usually made of metal, and a valve for controlling the flow rate of the heat transfer working fluid is arranged inside it. The valve is opened when filling the heat transfer working fluid into the cavity of the two-phase heat dissipation system, and automatically closes after filling is completed.

[0104] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A two-phase heat dissipation system, characterized in that, it includes: a heat pipe housing (16), the first end of the heat pipe housing (16) is a condensation pipe section (1), the second end is an evaporation pipe section (3), a transport pipe section (2) is arranged between the condensation pipe section (1) and the evaporation pipe section (3), and the transport pipe section (2) is made of a bendable flexible material; a microfluidic component, including a transport section chip (27) arranged on the transport pipe section (2), the transport section chip (27) is used to transport the liquid heat transfer working medium from the condensation pipe section (1) to the evaporation pipe section (3), and the transport section chip (27) is made of a bendable flexible material.

2. The two-phase heat dissipation system according to claim 1, characterized in that, it further includes a protection component, the protection component is arranged on the transport pipe section (2) and is used to limit the maximum bending angle of the transport pipe section (2).

3. The two-phase heat dissipation system according to claim 2, characterized in that, the protection component includes a plurality of protection shells (14), the protection shells (14) are sequentially sleeved outside the transport pipe section (2) along the direction from the condensation pipe section (1) to the evaporation pipe section (3), and are arranged at intervals, and two adjacent protection shells (14) are bendably connected through a connection component.

4. The two-phase heat dissipation system according to claim 3, characterized in that, the connection component includes: an elastic member (17), the elastic member (17) is made of an elastic material and is arranged between two adjacent protection shells (14); a fixing member (18), the end of the elastic member (17) is connected to the protection shell (14) through the fixing member (18).

5. The two-phase heat dissipation system according to claim 3, characterized in that, the connection component includes: a hinge seat (20), arranged at one end of the protection shell (14) close to each other, and provided with a first hinge hole; a connecting member (19), arranged between two adjacent protection shells (14), and provided with a second hinge hole corresponding to the first hinge hole, and a hinge shaft (21) passes through the first hinge hole and the second hinge hole.

6. The two-phase heat dissipation system according to claim 1, characterized in that, an installation opening is provided on the evaporation pipe section (3), an evaporation bottom plate (25) is arranged at the installation opening, and a capillary core (15) or a hydrophilic coating is arranged on the evaporation bottom plate (25).

7. The two-phase heat dissipation system according to any one of claims 1-6, characterized in that, a condensation section chip (26) is arranged on the condensation pipe section (1), and the condensation section chip (26) is connected to the transport section chip (27).

8. The two-phase heat dissipation system according to claim 7, characterized in that, along the direction from the condensation pipe section (1) to the evaporation pipe section (3), a first electrode and a second electrode are sequentially arranged on the condensation section chip (26), and a transport section electrode (5) is arranged on the transport section chip (27); the size of the second electrode is smaller than the size of the first electrode and larger than the size of the transport section electrode (5).

9. The two-phase cooling system according to any one of claims 1-6, characterized in that, the extension length of the condenser tube section (1) is at least three times that of the evaporator tube section (3).

10. The two-phase cooling system according to any one of claims 1-6, characterized in that, the microfluidic component includes a control member (9) for controlling the energization sequence of the transport section electrodes (5) on the transport section chip (27); the control member (9) and the transport section chip (27) are of an integral structure, or the control member (9) is connected to the transport section chip (27) through a flexible wiring assembly.

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