A two-phase flow heat exchange structure, an evaporator, a condenser and a two-phase flow heat exchange system

Abstract

The present invention relates to the technical field of heat dissipation devices, and discloses a two-phase flow heat exchange structure, an evaporator, a condenser and a two-phase flow heat exchange system. The two-phase flow heat exchange structure includes an evaporation flow channel and a swirl flow channel connected to each other; the evaporation flow channel has a necking structure for promoting gas-liquid conversion; the swirl flow channel has a bending structure for separating gas and liquid. The evaporator includes the two-phase flow heat exchange structure. The condenser includes the two-phase flow heat exchange structure. The two-phase flow heat exchange system includes the evaporator and the condenser. By means of the two-phase flow heat exchange structure, the heat dissipation capacity of the two-phase flow heat exchange system is increased, and it is ensured that the driving device can operate safely for a long time, meeting the heat dissipation requirements of extreme environments. Further, miniaturization and light weight of the two-phase flow heat exchange system can be achieved, so that it can be applied to small devices such as small aircraft, greatly broadening the application scenarios and usage ranges of the two-phase flow heat exchange system.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation devices, and particularly to a two-phase flow heat exchange structure, an evaporator, a condenser, and a two-phase flow heat exchange system. Background Art

[0002] With the development of the integration direction of electronic devices and the continuous improvement of usage requirements, the heat dissipation of electronic devices faces challenges such as complex heat source structures and high heat flux densities, resulting in increasingly prominent heat dissipation problems. At present, due to the high chip integration of device integration and SIP / SOP technologies, the local heat flux density can reach dozens to hundreds of watts per square centimeter, restricting the development of electronic heat dissipation technologies. It is necessary to find more efficient heat dissipation technologies to cope with future challenges. The two-phase flow cooling system uses the gas-liquid phase change conversion of liquid working media for heat transfer, has a high heat exchange efficiency, and its heat dissipation capacity can reach hundreds of watts per square centimeter, showing good application prospects in future airborne electronic devices.

[0003] Existing two-phase flow heat dissipation devices have the following problems: they essentially play a role in temperature equalization, cannot substantially improve the heat dissipation capacity of the system or device, and have limited application ranges. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that existing two-phase flow heat dissipation devices play a role in temperature equalization. The purpose is to provide a two-phase flow heat exchange structure, an evaporator, a condenser, and a two-phase flow heat exchange system to solve the above problems.

[0005] The present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a two-phase flow heat exchange structure, including an evaporation flow channel and a swirl flow channel connected to each other;

[0007] The evaporation flow channel has a necking structure for promoting gas-liquid conversion;

[0008] The swirl flow channel has a bending structure for separating gas and liquid.

[0009] In a possible design, the evaporation flow channel includes an inflow area, an evaporation tube, and an outflow area. The inflow area and the outflow area are oppositely arranged. At least one evaporation tube is provided and used to connect the inflow area and the outflow area. The necking structure is provided at one end of the evaporation tube adjacent to the inflow area.

[0010] In a possible design, the cross-sectional area of the evaporation tube is S1, and the cross-sectional area of the necking structure is S2, where S1≥2S2.

[0011] In a possible design, the swirl flow channel includes a plurality of arc-shaped flow channels and a plurality of bending structures;

[0012] The adjacent arc-shaped flow channels are coaxial and arranged at intervals, so that a plurality of arc-shaped flow channels are located on the same plane;

[0013] The adjacent arc-shaped flow channels are connected by a bending structure, so that the adjacent arc-shaped flow channels are communicated to form a spiral pipe with a single flow direction and a bend;

[0014] Correspondingly, in the outermost arc-shaped flow channel and the innermost arc-shaped flow channel, one of them is used for the inflow of the working fluid, and the other is used for the outflow of the working fluid, and additional bending structures for changing the flow direction are provided at both the working fluid inflow and the working fluid outflow.

[0015] In a possible design, a sector area is provided on the swirl flow channel, and both ends of the arc-shaped flow channel are respectively located on both sides of the sector area. Correspondingly, a plurality of bending structures are respectively located on both sides of the sector area and connect the adjacent arc-shaped flow channels.

[0016] In a possible design, an etching layer for cooperating with the necking structure is provided on the evaporation flow channel, and a sandblasting layer for cooperating with the bending structure is provided on the swirl flow channel;

[0017] The etching layer is obtained through the following steps:

[0018] S10 Configure the etching solution: Prepare a mixture of ferric chloride and hydrochloric acid;

[0019] S20 Etching: Add an inhibitor, and / or, perform intermittent etching. The intermittent etching uses etching for 40 s, cleaning for 20 s and repeating;

[0020] S30 Micro-arc oxidation treatment: Obtain an oxide layer with a thickness of 10 μm - 20 μm;

[0021] The sandblasting layer is obtained through the following steps:

[0022] S10 Equipment selection: Corundum powder with a diameter less than 0.3 mm, a low-pressure compressed air system with a pressure of 0.2 - 0.4 MPa, and a flexible micro-spray nozzle with an inner diameter ≤ 0.5 mm;

[0023] S20 Sandblasting: At the arc-shaped pipe, every 14 cm - 16 cm is divided into a sandblasting section, and sandblasting is performed section by section. The flexible micro-spray nozzle is parallel to the swirl flow channel, and the sandblasting angle is 5° - 10°; Pulse sandblasting is used at the bending structure;

[0024] S30 Inspection: Surface roughness inspection and flow channel airtightness test;

[0025] Among them, in S30, the surface roughness of the sandblasting layer needs to reach Ra12.5 μm.

[0026] In a second aspect, the present invention provides an evaporator based on the two-phase flow heat exchange structure described above, including a housing, a heater and the two-phase flow heat exchange structure;

[0027] The housing includes a cover plate, a steam generator, and an evaporator cavity arranged in sequence from bottom to top. The heater is arranged on the cover plate and is used to heat the steam generator. The two-phase flow heat exchange structure is arranged in the evaporator cavity, and the evaporation flow channel is located between the heater and the swirl flow channel.

[0028] In a third aspect, the present invention provides a condenser based on the two-phase flow heat exchange structure, including the two-phase flow heat exchange structure. Among them, the two-phase flow heat exchange structure includes an evaporation flow channel and two parallel swirl flow channels, so that the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser is ≥ 94%.

[0029] In a fourth aspect, the present invention provides a two-phase flow heat exchange system, including the evaporator, the condenser, an auxiliary port, a liquid storage tank, and a driving device;

[0030] The evaporator, the condenser, the auxiliary port, the liquid storage tank, and the driving device are connected in sequence to form a closed heat dissipation loop. The liquid filling amount of the heat dissipation loop is not less than 90%. The evaporator is arranged near the heat source and is used to absorb heat. The auxiliary port is used as a liquid replenishment port and an inspection port.

[0031] In a possible design, the liquid storage tank includes a tank body and an extraction flow channel;

[0032] The tank body has an upper cavity and a lower cavity opposite to each other. A gas release valve and an inlet are provided on the upper cavity, and an outlet is provided on the lower cavity. Correspondingly, pipes are respectively connected to the inlet and the outlet. The extraction flow channel is located between the upper cavity and the lower cavity;

[0033] Spirally downward fins are provided on the outer periphery of the extraction flow channel. The outer peripheral surface of the extraction flow channel is closely attached to the inner peripheral surface of the tank body, so that a one-way flow channel is formed between adjacent two fins. The one-way flow channel is tangent to both the inlet and the outlet, so that the working medium flows in and out tangentially;

[0034] Correspondingly, additional pipes tangent to the one-way flow channel are respectively provided at the upper and lower ends of the extraction flow channel.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] The heat dissipation capacity of the two-phase flow heat exchange system is increased through the two-phase flow heat exchange structure, and it is ensured that the driving device can operate safely for a long time, meeting the heat dissipation requirements of extreme environments. Further, the miniaturization and light weight of the two-phase flow heat exchange system can be realized, so as to be applied to equipment such as aircraft, greatly broadening the application scenarios and usage ranges of the two-phase flow heat exchange system. Description of the Drawings

[0037] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0038] Figure 1 It is a schematic structural diagram of a two-phase flow heat exchange structure.

[0039] Figure 2 It is a schematic structural diagram of an evaporation flow channel.

[0040] Figure 3 It is a schematic structural diagram of a swirl flow channel.

[0041] Figure 4 It is a schematic structural diagram of a two-phase flow heat exchange system.

[0042] Figure 5 It is a schematic structural diagram of an evaporator based on the two-phase flow heat exchange structure.

[0043] Figure 6 It is a schematic structural diagram of a condenser based on the two-phase flow heat exchange structure.

[0044] Figure 7 It is a schematic structural diagram of a liquid storage tank.

[0045] Figure 8 It is a schematic diagram of the system direction orientation.

[0046] Figure 9 It is a schematic diagram of the spectral line of functional vibration.

[0047] Figures 10 - 12 It is a temperature change curve graph of the two-phase flow heat exchange system in the X direction, Y direction, and Z direction respectively in a vibration environment.

[0048] Figures 13 - 16 It is a temperature change curve graph of the existing two-phase flow heat dissipation system in the X+ direction, X- direction, Y+ direction, and Y- direction respectively in an acceleration environment.

[0049] Figure 17 It is a schematic diagram of the internal fluid distribution of the liquid storage and distributor of the existing two-phase flow heat dissipation system in an acceleration environment.

[0050] Figures 18 - 23 It is a temperature change curve graph of the two-phase flow heat exchange system in the X+ direction, X- direction, Y+ direction, Y- direction, Z+ direction, and Z- direction respectively in an acceleration environment.

[0051] Marks in the drawings and corresponding component names:

[0052] 10. Evaporation flow channel; 101. Inflow area; 102. Evaporation tube; 103. Outflow area; 104. Necking structure; 20. Swirl flow channel; 201. Arc flow channel; 202. Bending structure; 203. Additional bending structure; 204. Sector area; 30. Evaporator; 31. Housing; 32. Heater; 301. Cover plate; 302. Steam generator; 303. Evaporator cavity; 40. Condenser; 50. Auxiliary port; 60. Liquid storage tank; 61. Tank body; 62. Extraction flow channel; 601. Upper cavity; 602. Lower cavity; 603. Air release valve; 604. Inlet; 605. Outlet; 606. Fins; 607. Additional pipeline; 70. Driving device. Specific embodiments

[0053] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0054] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those of ordinary skill in the art that the present invention does not have to employ these specific details. In other embodiments, well-known structures, circuits, materials or methods have not been specifically described in order to avoid obscuring the present invention.

[0055] Throughout the specification, references to "one embodiment", "an embodiment", "one example" or "an example" mean that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, the phrases "one embodiment", "an embodiment", "one example" or "an example" appearing throughout the specification do not necessarily all refer to the same embodiment or example. Furthermore, the particular features, structures or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the diagrams provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0056] In the description of the present invention, the orientation or positional relationships indicated by the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention.

[0057] Example 1:

[0058] In this example, a two-phase flow heat exchange system is provided. The two-phase flow heat exchange system includes an evaporator 30, a condenser 40, an auxiliary port 50, a liquid storage tank 60, and a driving device 70.

[0059] It is easy to understand that the two-phase flow heat exchange system further includes a fluid pipeline. Each component is connected through the fluid pipeline to form a closed heat dissipation loop. A working medium for heat dissipation is installed in the fluid pipeline. Further, any suitable existing pipeline can be selected for the fluid pipeline, and any suitable existing heat dissipation working medium can be selected for the working medium.

[0060] During operation, using the heating element as the heat source and the working medium as the heat carrier, the working medium absorbs the heat of the heating element in the evaporation section of the heat dissipation loop, causing the liquid working medium to evaporate when heated, and flowing in the form of gas to the condenser 40. It becomes liquid under the cooling effect of the condenser 40, and the heat is transferred to the external heat sink through the wall of the condenser 40, realizing the transfer of heat, thereby reducing the working temperature of the heating element. The liquid working medium condensed in the condenser 40 flows back to the evaporator 30 through the fluid pipeline under the driving force of the driving device 70. Then, it absorbs heat, evaporates, and flows again in the evaporator 30, continuously transferring the heat in the evaporator 30 to the remote heat sink, thereby stably and continuously reducing the temperature of the heating element.

[0061] Compared with the existing two-phase flow heat dissipation system, in the two-phase flow heat exchange system, the driving device 70 is used as the driving source, thereby providing additional power for the flow of the working medium in the system, overcoming the resistance of the system. In the case of multi-directional acceleration, vibration, etc., the working medium can still flow along the designed route, effectively expanding the application range of the two-phase flow heat exchange system.

[0062] Optionally, the working medium can be selected as acetone or ammonia water, or different working media can be matched according to the power consumption of different heating elements. It is easy to understand that other any suitable working media can also be selected.

[0063] It should be noted that after adding the driving device 70, the two-phase flow heat exchange system has more diverse usage scenarios, but is still limited to conventional scenarios, including but not limited to in-vehicle cooling systems under stable acceleration, and conventional gravity environment cooling systems in experimental environments. For special scenarios, such as aircraft at high altitude and multi-angle acceleration, due to the sensitivity of two-phase flow to acceleration and vibration, its working efficiency will be greatly reduced, and even directly fail in extreme cases, causing the collapse of the cooling system and directly burning the heat dissipation element.

[0064] In view of this, a two-phase flow heat exchange structure is proposed here. Specifically:

[0065] like Figures 1 - 6 As shown, a two-phase flow heat exchange structure includes an evaporation flow channel 10 and a swirl flow channel 20 connected to each other;

[0066] The evaporation channel 10 has a constriction structure 104 for promoting gas-liquid conversion;

[0067] The cyclone flow channel 20 has a bending structure 202 for separating gas and liquid.

[0068] For a two-phase flow heat exchange system, since the working fluid will change state between liquid and gas, if the proportion of the gaseous working fluid is relatively large, that is, the heat dissipation efficiency of the two-phase flow heat exchange system is low, it is inevitable that the gaseous working fluid will flow into the drive device 70. The gaseous working fluid will cause cavitation on the blades of the drive device 70, resulting in damage to the drive device 70, causing the two-phase flow heat exchange system to lose driving force.

[0069] Based on this, for the two-phase flow heat exchange structure, the gas-liquid conversion efficiency is increased by the evaporation channel 10, assisted by the constriction structure 104, that is, when the cross-sectional area of ​​the evaporation channel 10 is suddenly reduced, the fluid flow rate increases sharply. According to Bernoulli's principle, the increase in flow rate will cause the local pressure to decrease. If the temperature of the fluid is close to the saturation temperature at this time, the pressure drop will directly trigger the liquid vaporization (flash effect). At the same time, the sudden change in cross-sectional area will induce turbulence, destroy the thermal boundary layer of the fluid, enhance the heat exchange efficiency between the liquid and the high-temperature wall, and promote the gasification effect of the liquid. At the same time, turbulence can also increase the bubble nucleation rate of the phase change working fluid, thereby accelerating the gas-liquid conversion effect.

[0070] Therefore, for the evaporator 30, after the two-phase flow heat exchange structure is applied, the flash effect and the turbulence caused by the constriction structure 104 are used to increase the heat absorption of the working fluid, effectively improving the upper limit and heat absorption capacity of the two-phase flow heat exchange system, and the heat generated by the heating element is timely absorbed and transferred, so as to achieve the purpose of protecting the heating element. For the condenser 40, after the two-phase flow heat exchange structure is applied, the turbulence is caused by the constriction structure 104, and the heat exchange efficiency between the gas and the low-temperature wall is enhanced. With the help of the heat dissipation components in the condenser 40, such as heat dissipation fins, heat dissipation fans, etc., the heat is dissipated in time, and the working fluid is rapidly liquefied, so as to ensure that the liquid accounts for a large proportion in the gas-liquid mixture flowing out of the condenser 40, thereby protecting the drive device 70.

[0071] The swirling flow channel 20 is used to guide the working fluid to flow in a spiral direction. The flow direction is reversed through the bending structure 202, increasing the contact area between the gas-liquid mixture and the channel wall. At the same time, by utilizing the surface tension of the liquid droplets in the gas-liquid mixture and the centrifugal force of the swirling flow channel 20, the gas-liquid mixture undergoes centrifugal motion to promote gas-liquid separation, improving the gas-liquid conversion efficiency while ensuring the stability and safety of the entire system. The bending structure 202 is further provided. When the gas-liquid mixture flows to the bending structure 202, the liquid droplets in the gas-liquid mixture impact and converge on the wall surface of the bending structure 202, causing the liquid droplets to stay in the channel, which helps with the separation of the gas-liquid mixture and further ensures the purity of the outflowing gas through gas-liquid separation.

[0072] Thus, for the evaporator 30, the residence time of the liquid in the evaporator 30 increases, and there is more sufficient heat exchange time between the liquid working fluid and the heating element, improving the heat absorption efficiency and effect of the working fluid and transferring the heat generated by the heating element in a timely manner, enhancing the heat absorption capacity of the two-phase flow heat exchange system. For the condenser 40, the swirling flow channel 20 is used to achieve gas-liquid separation. The separated gas is further cooled and liquefied, ensuring that the liquid proportion in the gas-liquid mixture flowing out of the condenser 40 is large.

[0073] In summary, through the two-phase flow heat exchange structure, the heat dissipation capacity of the two-phase flow heat exchange system is increased, and it is ensured that the driving device 70 can operate safely for a long time, meeting the heat dissipation requirements in extreme environments. Further, the miniaturization and lightweight of the two-phase flow heat exchange system can be achieved, so that it can be applied to small devices such as small aircraft, greatly expanding the application scenarios and usage ranges of the two-phase flow heat exchange system.

[0074] In a possible implementation, the evaporation flow channel 10 includes an inflow area 101, evaporation tubes 102, and an outflow area 103. The inflow area 101 and the outflow area 103 are oppositely arranged. There is at least one evaporation tube 102 for connecting the inflow area 101 and the outflow area 103, and the reduced-diameter structure 104 is provided at one end of the evaporation tube 102 adjacent to the inflow area 101.

[0075] Based on the above design, there are multiple evaporation tubes 102. Compared with a single large-diameter pipe, on the basis of ensuring the working fluid flow rate, the contact area between the working fluid and the pipe is increased, the heat exchange area between the working fluid and the heating element is larger, and the heat exchange is more sufficient. At the same time, the reduced-diameter structure 104 is provided at the inlet of the evaporation tube 102 to enhance the liquid-gas conversion efficiency.

[0076] Correspondingly, the inflow area 101 and the outflow area 103, which can be configured in any suitable shape, are provided to realize the connection between the evaporation tubes 102 and surrounding components. The inflow area 101 also has a flow splitting function, and the outflow area 103 also has a flow converging function, enabling multiple evaporation tubes 102 to work simultaneously, improving the heat exchange effect and efficiency.

[0077] Optionally, as Figure 1 , Figure 2 , Figure 5 and Figure 6 shown, the inflow area 101 and the outflow area 103 can be constructed as flat structures, providing sufficient space for the connection of multiple evaporation tubes 102, and also enabling the inflow area 101, the multiple evaporation tubes 102, and the outflow area 103 to be in the same plane, so as to reduce the space occupied by the evaporation flow channel 10, which helps to realize the miniaturization and standardization of related equipment.

[0078] In a possible implementation, the cross-sectional area of the evaporation tube 102 is S1, and the cross-sectional area of the necking structure 104 is S2, where S1≥2S2. Based on the above design scheme, by restricting the ratio of the cross-sectional areas of the evaporation tube 102 and the necking structure 104, it is ensured that a flashing effect and turbulence are caused when the working fluid flows through the necking structure 104.

[0079] It is easy to understand that when the evaporation flow channel 10 is applied to the evaporator 30, in order to achieve the flashing effect, the external temperature needs to reach the saturation temperature of the working fluid. In addition to the heat supply of the heating element, a heating component can be set to ensure that the temperature of the working fluid when flowing through the necking structure 104 reaches its saturation temperature.

[0080] In a possible implementation, the swirl flow channel 20 includes a plurality of arc-shaped flow channels 201 and a plurality of bending structures 202;

[0081] Adjacent arc-shaped flow channels 201 are coaxial and spaced apart, so that the plurality of arc-shaped flow channels 201 are located in the same plane;

[0082] Adjacent arc-shaped flow channels 201 are connected by bending structures 202, so that adjacent arc-shaped flow channels 201 are connected and communicate with each other to form a spiral pipe with a single flow direction and bends;

[0083] Correspondingly, among the outermost arc-shaped flow channel 201 and the innermost arc-shaped flow channel 201, one is for the inflow of the working fluid and the other is for the outflow of the working fluid, and additional bending structures 203 for changing the flow direction are provided at both the working fluid inflow and the working fluid outflow.

[0084] Based on the above design scheme, the plurality of arc-shaped flow channels 201 are coaxial, so that the swirl flow channel 20 also has a flat structure, reducing the space occupied by the swirl flow channel 20, which helps to realize the miniaturization and standardization of related equipment. From the inside to the outside, the plurality of arc-shaped flow channels 201 are constructed as spiral line structures, but there are breaks between adjacent two arc-shaped flow channels 201, and the bending structures 202 are located at the breaks and connect the adjacent two arc-shaped flow channels 201, realizing the connection and communication of the adjacent two arc-shaped flow channels 201, and also enabling the working fluid to turn at the bending structures 202.

[0085] In other words, when the working fluid flows along the arc-shaped flow channel 201, the flow velocity of the working fluid is fast enough to cause a centrifugal effect on the gas-liquid mixture, thereby promoting the separation of the liquid droplets with a larger mass from the gas and achieving the effect of gas-liquid separation. When the working fluid flows to the bending structure 202, the working fluid turns, and during the turning process, the flowing working fluid will inevitably collide with the bending structure 202. The liquid droplets in the working fluid converge on the bending structure 202 after impact, forming large liquid droplets and staying at the bending structure 202, which helps to improve the separation effect of the gas-liquid separation of the working fluid. For the entire swirl structure, it effectively increases the contact area between the working fluid and the swirl flow channel 20, so that the liquid droplets can be adsorbed on the swirl flow channel 20 as much as possible by using the surface tension of the liquid droplets, realizing the liquid-gas separation of the working fluid.

[0086] Similarly, since the swirl flow channel 20 is configured as a flat structure, among the inlet and outlet of the working fluid of the swirl flow channel 20, at least an additional bending structure 203 needs to be provided at the outlet to increase the number of collisions of the working fluid while realizing the connection. Therefore, an additional bending structure 203 is preferably provided at the inlet of the working fluid to further increase the number of collisions of the working fluid.

[0087] In addition, when the swirl flow channel 20 is applied to the evaporator 30 and there is a heating component for heating the working fluid in the evaporator 30, the heat of the heating component can also be transferred to and heat the swirl flow channel 20. For the liquid droplets remaining on the bending structure 202, they can be vaporized under the combined heating of the heating component and the heating component, improving the gas-liquid conversion rate.

[0088] It is easy to understand that the bending structure 202 and the additional bending structure 203 can be respectively configured into any suitable shape.

[0089] In a possible implementation manner, as Figure 3 shown, a fan-shaped area 204 is provided on the swirl flow channel 20. The two ends of the arc-shaped flow channel 201 are respectively located on both sides of the fan-shaped area 204. Correspondingly, a plurality of bending structures 202 are respectively located on both sides of the fan-shaped area 204 and connect adjacent arc-shaped flow channels 201. Based on the above design scheme, the breaks in the plurality of arc-shaped flow channels 201 are located in the same area and communicate with each other to form the fan-shaped area 204, making the structure of the swirl flow channel 20 more symmetrical, more convenient for production and manufacturing, and having better structural performance.

[0090] Optionally, as Figure 3 shown, there are 8 arc-shaped flow channels 201 provided and arranged coaxially from the outside to the inside. The 8 arc-shaped flow channels 201 are connected by 16 bending structures 202. Correspondingly, there are also 2 additional bending structures 203 to respectively connect the outermost arc-shaped flow channel 201 and the innermost arc-shaped flow channel 201.

[0091] It should be noted that the more the number of bends, the better the gas-liquid separation effect, but it will increase the power consumption of the driving device 70. Therefore, in actual use, on the premise that the gas-liquid separation ratio meets the usage requirements, the number of bends should be minimized as much as possible.

[0092] Combined with the descriptions of the evaporation channel 10 and the swirl channel 20, for the two-phase flow heat dissipation structure, its gas-liquid conversion efficiency of the working medium is improved through structural improvement. On the basis of the structural improvement, the two-phase flow heat dissipation structure can also be provided with a functional layer to further improve the gas-liquid conversion efficiency. Specifically:

[0093] In a possible implementation manner, an etching layer for cooperating with the necking structure 104 is provided on the evaporation channel 10, and a sandblasting layer for cooperating with the bending structure 202 is provided on the swirl channel 20.

[0094] Based on the above design scheme, an etching layer is obtained on the evaporation channel 10 through an etching process. The etching layer effectively increases the internal roughness and the flow channel surface area of the evaporation channel 10, and promotes the adsorption of liquid droplets in the gas-liquid mixture. And considering that the cross-sectional area at the necking structure 104 is small, the etching can be completed by putting the etching solution into the necking structure 104, which solves the difficulty of equipment selection.

[0095] Similarly, a sandblasting layer is obtained on the swirl channel 20 through a sandblasting process. The sandblasting layer effectively increases the internal roughness and the flow channel surface area of the swirl channel 20, and promotes the adsorption of liquid droplets in the gas-liquid mixture. Considering that the cross-sectional area of the swirl channel 20 is relatively large, the sandblasting process can be selected for processing.

[0096] In a possible implementation manner, the etching layer is obtained through the following steps:

[0097] S10 Configure the etching solution: Prepare a mixture of ferric chloride and hydrochloric acid;

[0098] S20 Etching: Add an inhibitor, and / or, intermittent etching, the intermittent etching uses etching for 40 s, cleaning for 20 s and cycling;

[0099] S30 Micro-arc oxidation treatment: Obtain an oxide layer of 10 μm - 20 μm.

[0100] Based on this, in the process of obtaining the etching layer, in S10, the required etching solution is configured. It is easy to understand that generally a mixture of ferric chloride and hydrochloric acid is selected. When necessary, other any suitable etching solution can also be prepared according to the actual processing situation.

[0101] In S20, etching is performed using an etching solution. Before etching, attention should be paid to ensuring that the wall thickness of the evaporation channel 10 meets the safety requirements of the etching process to avoid etching through. During etching, attention should also be paid to the etching situation, and the etching rate and progress are controlled by adding corrosion inhibitors or intermittent etching to reduce the cumulative heat of the reaction and control the wall perpendicularity of the etched channels.

[0102] In S30, after etching is completed, micro-arc oxidation treatment is used to increase the hardness of the etched channels and improve the service life of the etched layer.

[0103] In a possible implementation, a sandblasted layer is obtained through the following steps:

[0104] S10 Equipment selection: Corundum powder with a diameter less than 0.3 mm, a low-pressure compressed air system with a pressure of 0.2 - 0.4 MPa, and a flexible micro-spray nozzle with an inner diameter ≤ 0.5 mm;

[0105] S20 Sandblasting: At the arc-shaped pipe, every 14 cm - 16 cm is divided into a sandblasting section, and sandblasting is carried out section by section. The flexible micro-spray nozzle is parallel to the swirl flow channel 20, and the sandblasting angle is 5° - 10°; Pulse sandblasting is used at the bending structure 202;

[0106] S30 Inspection: Surface roughness inspection and flow channel airtightness test;

[0107] Among them, in S30, the surface roughness of the sandblasted layer needs to reach Ra12.5 μm.

[0108] Based on this, during the process of obtaining the sandblasted layer, in S10, appropriate equipment is selected. And in this embodiment, a practical and feasible implementation scheme is given here, that is, corundum powder with a diameter less than 0.3 mm is used to reduce the probability of grit jamming the swirl flow channel 20; a low-pressure compressed air system with a pressure of 0.2 - 0.4 MPa and a flexible micro-spray nozzle with an inner diameter ≤ 0.5 mm are used to reduce the impact force of the grit during sandblasting and prevent deformation and damage of the swirl flow channel 20.

[0109] Optionally, the corundum powder is generally selected to be 20 μm - 50 μm. When necessary, other appropriate sizes can also be selected.

[0110] In S20, sandblasting is carried out using the equipment in S10. Considering the relatively large length of the swirl flow channel 20, sandblasting is carried out section by section after zoning. After each section is completed, its cleanliness needs to be checked, and then it is pushed to the next section. During sandblasting, the angle of the flexible micro-spray nozzle is controlled to achieve downstream spraying to reduce the rebound and accumulation of grit. For the bending structure 202, there are corners that are prone to fouling. Pulse sandblasting is used to improve the sandblasting accuracy and also helps to eliminate the fouling phenomenon.

[0111] In S30, the sandblasted layer is inspected to ensure that the sandblasted layer meets the usage requirements and there is no structural damage to the swirl flow channel 20.

[0112] Embodiment 2:

[0113] Based on the two-phase flow heat dissipation structure described in Embodiment 1, the application of the two-phase flow heat dissipation structure is introduced. Specifically:

[0114] As Figure 4 and Figure 5 shown, an evaporator based on the two-phase flow heat exchange structure described above includes a housing 31, a heater 32, and the two-phase flow heat exchange structure;

[0115] The housing 31 includes a cover plate 301, a steam generator 302, and an evaporator cavity 303 arranged in sequence from bottom to top. The heater 32 is arranged on the cover plate 301 and is used to heat the steam generator 302. The two-phase flow heat exchange structure is arranged in the evaporator cavity 303, and the evaporation flow channel 10 is located between the heater 32 and the swirl flow channel 20.

[0116] Based on the above design scheme, the evaporator 30 is divided into three parts, namely the heater 32 at the bottom, which serves as the bottom heat source; the evaporation flow channel 10 in the middle, which serves as the middle liquid-gas conversion structure; and the swirl flow channel 20 at the top, which serves as the top gas-liquid separation structure.

[0117] When the working fluid flows into the evaporator 30, the working fluid flows into the evaporation flow channel 10, absorbs heat in the evaporation flow channel 10 and becomes a gas, and the working fluid changes into a gas-liquid mixture and flows into the swirl flow channel 20. The gas-liquid mixture flows in the swirl flow channel 20 and undergoes gas-liquid separation, the gas flows out, and the liquid is temporarily stored. For the temporarily stored liquid, the heat of the heater 32 and / or the heating element is used to evaporate this part of the liquid.

[0118] It should be noted that the heater 32 is used to provide heat, and the heater 32 is located at the bottom of the evaporator 30. The heat of the heater 32 is transferred from bottom to top. The evaporation flow channel 10 helps to increase the heat exchange area and accelerate the gasification of the working fluid. Moreover, the heater 32, the evaporation flow channel 10, and the swirl flow channel 20 are arranged in sequence from bottom to top, so that the heat of the evaporation flow channel 10 can also be used to heat the liquid in the swirl flow channel 20. Based on this, the utilization rate of heat is improved and the gas-liquid conversion rate is increased.

[0119] It is easy to understand that the housing 31 is also preferably constructed as a flat structure to reduce the space occupied by the evaporator 30, so as to facilitate miniaturization and standardization. The heater 32 and the steam generator 302 can be selected from any suitable existing models.

[0120] Optionally, the heater 32 is selected as 4 ceramic heating elements, and the heating power of each ceramic heating element is between 100W and 350W. In one implementation, the power of each ceramic heating element is 250W, with a total heat consumption of 1000W.

[0121] As Figure 4 and Figure 6 shown, a condenser based on the two-phase flow heat exchange structure described above includes the two-phase flow heat exchange structure. Among them, the two-phase flow heat exchange structure includes an evaporation flow channel 10 and two parallel swirl flow channels 20, so that the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser 40 is ≥94%.

[0122] Based on the above design, both the condenser 40 and the evaporator 30 apply the two-phase flow heat dissipation structure. In the condenser 40 and the evaporator 30, the functions of the two-phase flow heat dissipation structure are different, and this difference has been described in Embodiment 1 and will not be elaborated here.

[0123] During operation, after the working fluid flows into the condenser 40, it releases heat to the outside and quickly liquefies in the evaporation flow channel 10. The remaining gas in the working fluid enters the swirl flow channel 20, and gas-liquid separation is achieved through the swirl flow channel 20. At the same time, any suitable heat dissipation equipment such as a heat dissipation fan and heat dissipation fins is supplemented to further liquefy the gas.

[0124] Furthermore, there is another difference between the condenser 40 and the evaporator 30, that is, the condenser 40 is provided with an evaporation flow channel 10 and two parallel swirl flow channels 20, that is, the number of swirl flow channels 20 is relatively large. Specifically, as the liquid proportion in the working fluid increases, the flow resistance of the working fluid flowing in the condenser 40 also increases. In order to reduce the influence of the flow resistance and relieve the pressure on the driving device 70, two parallel swirl flow channels 20 are provided to share the working fluid flowing out of the evaporation flow channel 10, greatly reducing the flow resistance.

[0125] It should be noted that when two swirl flow channels 20 are provided, the gas-liquid separation effect of the condenser 40 is better, ensuring that the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser 40 is ≥94%. Based on this, the content of the working fluid gas flowing into the driving device 70 is small, effectively reducing the damage of cavitation to the driving device 70 and ensuring the service life of the driving device 70.

[0126] Similarly, the condenser 40 is also preferably constructed as a flat structure to reduce space occupation, so as to facilitate miniaturization and standardization.

[0127] It is easy to understand that in order to improve the heat dissipation efficiency of the condenser 40, any suitable heat dissipation devices such as a heat dissipation fan and heat dissipation fins are provided on the condenser 40 to ensure that the working fluid flowing into the condenser 40 is fully liquefied, so that the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser 40 is ≥94%.

[0128] As Figures 1 - 7 shown, a two-phase flow heat exchange system includes the evaporator 30, the condenser 40, the auxiliary port 50, the liquid storage tank 60, and the driving device 70;

[0129] The evaporator 30, the condenser 40, the auxiliary port 50, the liquid storage tank 60, and the driving device 70 are connected in sequence to form a closed heat dissipation loop. The liquid filling amount of the heat dissipation loop is not less than 90%. The evaporator 30 is arranged adjacent to the heat source and is used to absorb heat. The auxiliary port 50 is used as a liquid filling port and an inspection port.

[0130] In the two-phase flow heat exchange system, the evaporator 30 and the condenser 40 have been described in combination with the two-phase flow heat exchange structure in Embodiment 1. The following describes the remaining components. Specifically:

[0131] When the auxiliary port 50 is used as a liquid filling port, the staff replenishes an appropriate amount of working fluid into the heat dissipation loop through the auxiliary port 50 to ensure that the liquid filling amount of the heat dissipation loop is not less than 90%. When the auxiliary port 50 is used as an inspection port, the staff checks the two-phase flow heat exchange system through the auxiliary port 50 to confirm the working condition of the two-phase flow heat exchange system.

[0132] The liquid storage tank 60 is used to store the excess liquid in the two-phase flow heat exchange system to maintain the stability of the system, avoid excessive saturation pressure inside, and can also achieve gas-liquid two-phase separation, preventing the incompletely cooled gas in the system from entering the driving device 70 and causing cavitation to the driving device 70, thereby affecting the performance of the other components in the system.

[0133] The driving device 70 serves as a power source and drives the working fluid to flow along the heat dissipation loop. It is easy to understand that the driving device 70 can be selected from any suitable existing equipment.

[0134] During operation, the driving device 70 starts and drives the working fluid to flow. When the working fluid flows to the evaporator 30, since the evaporator 30 is adjacent to the heat source, the working fluid absorbs heat and vaporizes. Due to the application of the two-phase flow heat exchange structure, the evaporator 30 has a high heat absorption efficiency, and the proportion of gas in the working fluid flowing out of the evaporator 30 is high. After flowing out of the evaporator 30, the working fluid flows into the condenser 40, where the working fluid releases heat and liquefies. Due to the application of the two-phase flow heat exchange structure, the condenser 40 has a high heat absorption efficiency, and the proportion of liquid in the working fluid flowing out of the condenser 40 is high. Specifically, the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser 40 is ≥94%. After the working fluid flows out of the condenser 40, it flows into the liquid storage tank 60 for gas-liquid separation and then into the driving device 70.

[0135] Thus, for the state of the working fluid in the heat dissipation loop, such as Figure 4 shown, the section where the working fluid flows out of the evaporator 30 and into the condenser 40 is a gas-dominated gas section. Conversely, the section where the working fluid flows out of the condenser 40 and into the evaporator 30 is a liquid-dominated liquid section.

[0136] For the extreme working conditions described in Embodiment 1, taking an aircraft at high altitude with multi-angle acceleration as an example, compared with the conventional vehicle-mounted environment, the movement of the aircraft has differences such as multi-angle acceleration and random vibration, and the flow of the working fluid will also be affected by the state of the aircraft. For example, when the aircraft accelerates, the working fluid in the heat dissipation loop will show a chaotic distribution and the phenomenon of working fluid aggregation, especially for the liquid working fluid, resulting in the abnormal operation of the two-phase flow heat exchange system and a discounted heat dissipation effect; even more, if a large amount of gaseous working fluid enters the driving device 70, the driving device 70 will be damaged due to cavitation, resulting in the inoperability of the two-phase flow heat exchange system.

[0137] In response to this, by controlling the liquid filling amount of the heat dissipation loop, it is ensured that there is enough working fluid flowing along the designed direction in the heat dissipation loop. At the same time, through the application of the two-phase flow heat exchange structure, the working efficiency of the evaporator 30 and the condenser 40 is improved, ensuring that even under extreme working conditions, the working fluid in the liquid section is mainly liquid, effectively protecting the driving device 70. In addition, a liquid storage tank 60 for controlling the liquid filling amount of the heat dissipation loop is also provided. Before the working fluid enters the driving device 70, gas-liquid separation of the working fluid is carried out to minimize the gas entering the driving device 70. The liquid storage tank 60 can also store excess liquid to maintain the stability and safety of the two-phase flow heat exchange system.

[0138] Based on this, for the two-phase flow heat exchange system, efficient heat dissipation is achieved, greatly improving the heat dissipation capacity and environmental adaptability of the two-phase flow heat exchange system, and effectively expanding the application range of the two-phase flow heat exchange system. Compared with the existing two-phase flow heat dissipation equipment, the gas-liquid separator is also eliminated in the two-phase flow heat exchange system, which helps to reduce the weight, decrease the volume, and achieve miniaturization and lightweight design.

[0139] Preferably, in the two-phase flow heat exchange system, argon arc welding is used to connect and seal each interface, improving the pressure-bearing capacity and reliability of the system.

[0140] Preferably, the modular concept is adopted in the design and production process of the two-phase flow heat exchange system, so as to manufacture products of different specifications, and the staff can select the appropriate specifications according to the actual working conditions.

[0141] In a possible implementation manner, the liquid storage tank 60 includes a tank body 61 and a pumping channel 62;

[0142] The tank body 61 has opposite upper cavity 601 and lower cavity 602. An air release valve 603 and an inlet 604 are provided on the upper cavity 601, and an outlet 605 is provided on the lower cavity 602. Correspondingly, pipes are respectively connected to the inlet 604 and the outlet 605. The extraction flow channel 62 is located between the upper cavity 601 and the lower cavity 602;

[0143] Spirally downward fins 606 are provided on the outer periphery of the extraction flow channel 62. The outer peripheral surface of the extraction flow channel 62 is closely attached to the inner peripheral surface of the tank body 61, so that a one-way flow channel is formed between two adjacent fins 606. The one-way flow channel is tangent to both the inlet 604 and the outlet 605, so that the working medium flows in and out tangentially;

[0144] Correspondingly, additional pipes 607 tangent to the one-way flow channel are respectively provided at the upper and lower ends of the extraction flow channel 62.

[0145] Based on the above design scheme, in the liquid storage tank 60, the spiral fins 606 and the tank body 61 cooperate with each other to form a spiral one-way flow channel. The function of this one-way flow channel is similar to that of the swirl flow channel 20, that is, it is used for the separation of gas and liquid in the working medium. The difference between the two is that the liquid-gas ratio of the gas-liquid mixture flowing out of the condenser 40 is ≥94%. Therefore, the one-way flow channel does not need to be provided with a bending structure 202.

[0146] It should be noted that the liquid storage tank 60 limits the flow direction of the working medium, that is, it flows from top to bottom. The working medium is affected by gravity and flows downward. Since the working medium flows along the spiral flow channel, under the action of centrifugal force, gas and liquid will be separated to a certain extent. At the same time, for the liquid in contact with the surface of the one-way flow channel, the contact area between the two is large, and the liquid is easily adsorbed on the one-way flow channel under the action of surface tension, further improving the gas-liquid separation effect. For this part of the liquid, it may also flow into the lower cavity 602 of the liquid storage tank 60 and be stored. In addition, the working medium flows tangentially, giving the working medium a tangential velocity along the fins 606, making it easier for the liquid to swirl out of the outlet 605 of the liquid storage tank 60 along the fins 606 inside the liquid storage tank 60, improving the gas-liquid separation efficiency of the liquid storage tank 60.

[0147] On the contrary, if the liquid flows from bottom to top, the working medium will fill the entire liquid storage tank 60 before flowing out from above the liquid storage tank 60, so that most of the working medium in the heat dissipation loop is stored in the liquid storage tank 60, greatly reducing the liquid filling amount in the heat dissipation loop, and will seriously affect the operation of the two-phase flow heat exchange system. In addition, when the liquid fills the liquid storage tank 60, both the gas and the liquid in the remaining working medium will flow out of the liquid storage tank 60, making the liquid storage tank 60 unable to achieve the function of gas-liquid separation.

[0148] An air release valve 603 is provided on the liquid storage tank 60 to timely release the gas remaining in the liquid storage tank 60, reduce the gas dissolution amount in the entire heat dissipation loop, and effectively avoid the situation of excessive pressure in the liquid storage tank 60.

[0149] It is easy to understand that pipelines are respectively connected to the inlet 604 and the outlet 605 of the tank body 61. Correspondingly, an additional pipeline 607 is provided on the extraction flow channel 62. When the extraction flow channel 62 is located inside the tank body 61, the additional pipeline 607 is inserted into the adjacent pipeline to guide the flow direction of the working medium through the additional pipeline 607, ensuring that the working medium flows in and out tangentially.

[0150] Embodiment 3:

[0151] Based on Embodiment 2, this embodiment conducts tests under vibration environment and acceleration environment respectively and verifies the effect of the two-phase flow heat exchange system described in Embodiment 2.

[0152] First, taking an aircraft in a vibration environment as an example, illustrate the heat dissipation effect of the two-phase flow heat exchange system under extreme working conditions:

[0153] The direction of the system is defined as Figure 8 shown. Using the random vibration method, the anti-vibration performance of a certain typical airborne electronic device function vibration environment is studied. The vibration spectrum is as Figure 9 shown, the vibration magnitude is 10.45G, the system heat input conditions under the vibration environment are the same as those under the normal system heat test heat input conditions, and the vibration directions are the three directions of X, Y, and Z.

[0154] As Figures 10 - 12 shown, the temperature change curve of the two-phase flow cooling system when working under the vibration environment conditions. It can be seen from the experimental results that the vibration has a small impact on the thermal performance of the system. When vibrating in the X and Y directions, the temperature change before and after the test is less than 2°C, and the impact is very small; when vibrating in the Z direction, the temperature change before and after the test is less than 5°C, which is slightly larger than the temperature difference change when vibrating in the X and Y directions. This is mainly because the heat source is installed in the Z direction of the evaporator 30, and the contact performance between the internal fluid of the system and the inner wall surface of the evaporator 30 decreases during Z-direction vibration, resulting in a decrease in heat transfer performance.

[0155] In summary, it can be seen that in a complex vibration environment, the two-phase flow heat exchange system reduces the impact of vibration on the heat dissipation performance of the system, effectively maintains the heat dissipation capacity, and ensures that the heating elements can work normally under extreme working conditions.

[0156] Second, taking an aircraft in an acceleration environment as an example, illustrate the heat dissipation effect of the two-phase flow heat exchange system under extreme working conditions:

[0157] Taking the two-phase flow heat exchange system described in Embodiment 2 as the experimental group and any existing two-phase flow heat dissipation system as the control group, experiments are carried out on the same aircraft, and multiple experiments are carried out under the conditions of multi-angle acceleration and a gravitational acceleration greater than 1G. Specifically:

[0158] The control group conducts experiments and obtains relevant data, that is, asFigures 13 - 16 As shown, they are the temperature change curves of the system under the acceleration environments in the X+, X-, Y+ and Y- directions respectively. The heat input conditions of the system under the acceleration environment are the same as those of the system during the thermal test at room temperature. The definition of the acceleration direction of the system is the same as that of the vibration implementation direction, and the acceleration test time is 1 min. When performing the acceleration test in the Z direction, since the system needs to be installed laterally, the liquid storage and distribution device is installed horizontally. The liquid in the liquid storage and distribution device cannot flow back normally, and the liquid in the system accumulates at the lower part of the system. What circulates in the system is gas, making the system unable to work properly and the Z-direction acceleration test cannot be carried out.

[0159] During the test, the external forces acting on the fluid inside the liquid storage and distribution device are mainly gravity and the resistance caused by acceleration. The fluid inside the liquid storage and distribution device is affected by two different external forces, resulting in a complex gas-liquid distribution. According to the analysis of the measured data, under the influence of the acceleration in the X-, Y+ and Y- directions, there are large fluctuations in the temperature of the heat source and the temperature changes greatly; while under the influence of the acceleration in the X+ direction, the temperature change range of the heat source is small. At the same time, during the acceleration experiments in the X-, Y+ and Y- directions, it is found that there is a sharp decrease in the driving current of the system driving pump. In the X-acceleration experiment, the driving current of the system driving pump decreases from 0.7 A to 0.38 A; in the Y+-acceleration experiment, the driving current of the system driving pump decreases from 0.7 A to 0.4 A; in the Y--acceleration experiment, the driving current of the system driving pump decreases from 0.7 A to 0.41 A. While in the X+-direction acceleration test, there is no sharp decrease in the driving current of the system driving pump, and the driving current of the system driving pump has been fluctuating around 0.7 A.

[0160] Since under the acceleration environment, the system driving pump has a large driving force to overcome the acceleration resistance to drive the normal flow of the internal fluid in the pipeline. However, in the liquid storage and distribution device, since the system realizes the gas-liquid separation of the fluid by centrifugal force, under the action of the acceleration external force, it will completely fail, and the gas-liquid distribution inside the liquid storage and distribution device will be chaotic. The fluid flowing out of the outlet of the liquid storage and distribution device into the system return pipeline may be liquid or gas. When the acceleration direction is opposite to the internal liquid flow direction of the liquid storage and distribution device, the liquid inside the liquid storage and distribution device accumulates in the liquid storage and distribution device, and mainly gas enters the pipeline, resulting in system failure; when the acceleration direction is the same as the internal liquid flow direction of the liquid storage and distribution device, mainly liquid enters the pipeline and the system works normally.

[0161] According to the analysis, this is mainly because the internal fluid of the liquid storage and distribution device is affected by the acceleration resistance, and the internal liquid appears as Figure 17The liquid distribution shown. Under the acceleration in the X+ direction, all the outlets of the liquid storage and distributor are liquid, so the fluid entering the system return pipeline is liquid, and there will be no large fluctuations in the thermal performance of the system. Under the acceleration conditions in other directions, the outlet of the liquid storage and distributor is a gas-liquid mixture, and the gas enters the system pipeline, resulting in large fluctuations in the thermal performance of the system. At the same time, the input current of the mechanical pump decreases. The main reason is that there are a lot of gases in the fluid in the system return pipeline, the system resistance is small, and the driving force required for the mechanical pump to drive the gas is smaller than that for driving the liquid, resulting in a significant decrease in the input current of the mechanical pump.

[0162] It is easy to understand that in the experimental records of the control group, the system refers to any existing two-phase flow heat dissipation system, and the system driving pump, liquid storage and distributor, pipeline, etc. are all components of any existing two-phase flow heat dissipation system.

[0163] The experimental group conducts experiments and obtains relevant data, that is, as Figures 18 - 23 shown is the thermal performance curve graph of the acceleration test system after changing the system liquid filling amount. It can be seen from the test data that under the action of various accelerations of the system, the temperature of the system heat source does not show an aggregated increase, the temperature fluctuation curve is relatively smooth, and the driving current of the driving device 70 does not show a sharp decrease, and the system works normally.

[0164] Combined with the analysis of the control group, in the existing two-phase flow heat dissipation system, the liquid storage and distributor uses the centrifugal principle for gas-liquid separation. Under the influence of acceleration in an indefinite direction, the distribution of the internal fluid of the existing two-phase flow heat dissipation system will show different distributions with the change of the acceleration direction. Specifically, under the influence of acceleration, the liquid inside the liquid storage and distributor cannot flow back into the return pipeline of the existing two-phase flow heat dissipation system, resulting in the failure of the existing two-phase flow heat dissipation system.

[0165] In view of this, in the experimental group, in Embodiment 2, the two-phase flow heat exchange system improves the structures of the evaporator 30, the condenser 40 and the liquid storage tank 60 on the one hand, and increases the liquid filling amount in the two-phase flow heat exchange system on the other hand, thereby effectively improving the refrigeration and heat dissipation efficiency of the two-phase flow heat exchange system under the acceleration state, as well as the stability and reliability of the system operation.

[0166] Based on this, in an acceleration environment, when the liquid filling amount of the two-phase flow heat exchange system is less than the volume of the liquid storage tank 60, when the acceleration direction causes the liquid in the two-phase flow heat exchange system to mainly gather in the liquid storage tank 60, there is less liquid flowing in the heat dissipation loop, resulting in system failure; when the liquid filling amount of the two-phase flow heat exchange system is greater than the volume of the liquid storage tank 60, when the two-phase flow heat exchange system is affected by the reverse acceleration, that is, the liquid gathers in the liquid storage tank 60, but when the liquid fills the liquid storage tank 60, the excess liquid will circulate in the heat dissipation loop under the action of the driving device 70, thereby avoiding the failure of the two-phase flow heat exchange system.

[0167] In summary, it can be seen that in an acceleration environment, especially under the conditions of multi-angle acceleration and a gravitational acceleration greater than 1G, the two-phase flow heat exchange system effectively overcomes the influence of acceleration on the heat dissipation capacity of the system, effectively maintains the heat dissipation capacity, and ensures that the heating element can operate normally under extreme conditions.

[0168] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A two-phase flow heat exchange structure, characterized in that: It comprises an evaporation flow channel (10) and a swirl flow channel (20) connected to each other; The evaporation flow channel (10) has a constriction structure (104) for promoting gas-liquid conversion; The cyclone flow channel (20) has a bending structure (202) for separating gas and liquid; The evaporation flow channel (10) comprises an inflow area (101), an evaporation tube (102) and an outflow area (103); the inflow area (101) and the outflow area (103) are arranged opposite to each other; the evaporation tube (102) is provided with at least one and is used to connect the inflow area (101) and the outflow area (103); and the shrinkage structure (104) is provided at one end of the evaporation tube (102) adjacent to the inflow area (101); The swirl flow channel (20) comprises a plurality of arc-shaped flow channels (201) and a plurality of bending structures (202); Adjacent arc-shaped flow channels (201) are coaxial and spaced apart, so that the plurality of arc-shaped flow channels (201) are located on the same plane; Adjacent arc-shaped flow channels (201) are connected via a bending structure (202) so that the adjacent arc-shaped flow channels (201) are connected to form a spiral pipeline with a single flow direction and a bend; Correspondingly, one of the outermost arc-shaped flow channel (201) and the innermost arc-shaped flow channel (201) is used for the inflow of working fluid, and the other is used for the outflow of working fluid, and both the inflow and outflow of working fluid are provided with additional bending structures (203) for changing the flow direction.

2. The two-phase flow heat exchange structure according to claim 1, characterized in that: The cross-sectional area of ​​the evaporation tube (102) is S1, the cross-sectional area of ​​the necking structure (104) is S2, and S1≥2S2.

3. The two-phase flow heat exchange structure according to claim 1, characterized in that: A fan-shaped area (204) is provided on the swirl flow channel (20), and two ends of the arc-shaped flow channel (201) are respectively located on both sides of the fan-shaped area (204). Correspondingly, a plurality of bending structures (202) are respectively located on both sides of the fan-shaped area (204) and connect adjacent arc-shaped flow channels (201).

4. The two-phase flow heat exchange structure according to any one of claims 1 to 3, characterized in that: An etching layer for matching the necking structure (104) is provided on the evaporation flow channel (10), and a sandblasting layer for matching the bending structure (202) is provided on the swirl flow channel (20); The etched layer is obtained by the following steps: S10: preparing an etching solution: preparing a mixture of ferric chloride and hydrochloric acid; S20 etching: adding corrosion inhibitor, and / or, intermittent etching, the intermittent etching adopts etching for 40s, cleaning for 20s and cycle; S30 micro-arc oxidation treatment: obtain an oxide layer of 10μm-20μm; The sandblasting layer is obtained by the following steps: The S10 equipment uses: corundum powder with a diameter less than 0.3mm, a low-pressure compressed air system with a pressure of 0.2-0.4MPa, and a flexible micro-spray nozzle with an inner diameter of ≤0.5mm; S20 sandblasting: At the curved pipe, every 14 cm to 16 cm is divided into a sandblasting section, and sandblasting is performed section by section, and the flexible micro-spray nozzle is parallel to the swirl flow channel (20), and the sandblasting angle is 5° to 10°; pulse sandblasting is used at the bending structure (202); S30 inspection: surface roughness inspection and flow channel air tightness test; Among them, in S30, the surface roughness of the sandblasting layer needs to reach Ra12.5μm.

5. An evaporator based on the two-phase flow heat exchange structure according to any one of claims 1 to 4, characterized in that: It comprises a shell (31), a heater (32) and the two-phase flow heat exchange structure; The shell (31) comprises a cover plate (301), a steam generator (302) and an evaporator cavity (303) which are arranged in sequence from bottom to top; the heater (32) is arranged on the cover plate (301) and is used to heat the steam generator (302); the two-phase flow heat exchange structure is arranged in the evaporator cavity (303); and the evaporation flow channel (10) is located between the heater (32) and the swirl flow channel (20).

6. A condenser based on the two-phase flow heat exchange structure according to any one of claims 1 to 4, characterized in that: The two-phase heat exchange structure comprises an evaporation flow channel (10) and two parallel swirl flow channels (20), so that the liquid-to-gas ratio of the gas-liquid mixture flowing out of the condenser (40) is ≥94%.

7. A two-phase flow heat exchange system, characterized in that: It comprises the evaporator (30) according to claim 5, the condenser (40) according to claim 6, an auxiliary port (50), a liquid storage tank (60) and a driving device (70); The evaporator (30), the condenser (40), the auxiliary port (50), the liquid storage tank (60) and the drive device (70) are connected in sequence to form a closed heat dissipation circuit. The liquid filling volume of the heat dissipation circuit is not less than 90%. The evaporator (30) is arranged near the heat source and is used to absorb heat. The auxiliary port (50) is used as a liquid filling port and an inspection port.

8. The two-phase flow heat exchange system according to claim 7, characterized in that: The liquid storage tank (60) comprises a tank body (61) and an extraction flow channel (62); The tank body (61) comprises an upper cavity (601) and a lower cavity (602) which are opposite to each other. The upper cavity (601) is provided with an air release valve (603) and an inlet (604), and the lower cavity (602) is provided with an outlet (605). Correspondingly, the inlet (604) and the outlet (605) are respectively connected to pipelines. The extraction flow channel (62) is located between the upper cavity (601) and the lower cavity (602). The outer periphery of the extraction flow channel (62) is provided with fins (606) spiraling downward, and the outer peripheral surface of the extraction flow channel (62) is closely attached to the inner peripheral surface of the tank body (61), so that a one-way flow channel is formed between two adjacent fins (606), and the one-way flow channel is tangent to both the inlet (604) and the outlet (605), so that the working fluid flows in and out in a tangential direction; Correspondingly, the upper and lower ends of the extraction flow channel (62) are respectively provided with additional pipes (607) that are tangent to the one-way flow channel.

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