Flow boiling multiphase flow heat transfer enhancement device based on aerophile degassing film and working method of flow boiling multiphase flow heat transfer enhancement device

Abstract

The invention provides a flow boiling multiphase flow heat transfer strengthening device based on an aerophilic degassing film and a working method, and belongs to the technical field of two-phase flow and heat transfer strengthening. The problems that in the micro-channel flowing boiling process, bubbles cannot be discharged in time, so that flow distribution is uneven, critical heat flow is advanced, and the temperature rises abnormally are solved. The device comprises a sample piece upper layer, an aerophilic degassing structure layer, a star-shaped aerophilic degassing structure, a sample piece lower layer, diamond needle-shaped ribs, a sample piece inlet water collecting chamber, a vacuum negative pressure chamber and a sample piece outlet water collecting chamber, the aerophilic degassing structure layer is installed between the sample piece upper layer and the sample piece lower layer, and the space formed between the left end of the sample piece upper layer and the sample piece lower layer is the sample piece inlet water collecting chamber; a space formed between the right end of the sample piece upper layer and the sample piece lower layer is a sample piece outlet water collecting chamber, and the middle of the sample piece upper layer and a vacuum negative pressure area in the middle of the aerophilic degassing structure layer form a vacuum negative pressure chamber. The heat dissipation system is mainly used for achieving rapid separation and efficient discharge of bubbles.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of two-phase flow and heat transfer enhancement, and particularly relates to a flow boiling multi-phase flow heat transfer enhancement device based on a gas-favorable degassing film and a working method. BACKGROUND

[0002] With the rapid development of micro-electro-mechanical systems and high-power microelectronic devices, the integration of equipment is continuously improved, the heat generation per unit volume is significantly increased, and the heat dissipation space is increasingly limited, which poses a severe challenge to the thermal management capability of the system. Efficient heat dissipation technology has become a key factor to guarantee the safe and stable operation of micro-electro-mechanical systems. In the operation process of micro-electro-mechanical systems, the increase of working temperature will cause the failure rate of electronic components to increase exponentially. According to research, when the working temperature of electronic devices is in the range of 70-80℃, the failure probability of the electronic devices will increase by about 5% for each 1℃ increase in temperature. Due to the limited heat conduction capacity of traditional heat dissipation materials and devices, the micro-electro-mechanical system can currently only exhibit 20-30% of its theoretical performance. Therefore, in order to fully exploit the performance potential of microelectronic devices and improve the operational stability and energy efficiency of the system, it is urgent to develop efficient heat dissipation technology. In recent years, micro-channel cooling technology has become an important direction for high heat flux electronic chip heat dissipation due to its high specific surface area and good thermal management capability. Compared with single-phase flow cooling, two-phase flow boiling cooling based on latent heat can significantly improve the heat dissipation capacity under the same volume condition, and has shown a broader application prospect.

[0003] In the process of micro-channel flow boiling, with the increase of wall superheat, the vapor bubbles undergo a series of dynamic processes such as nucleation, growth, coalescence and detachment. The rapid detachment of bubbles on the heating surface will cause the rewetting of the surrounding liquid and significantly enhance the convective heat transfer process. However, with the further increase of superheat, more potential nucleation points are activated, and the bubble generation density increases significantly. The formation and coalescence of a large number of bubbles not only cause uneven flow distribution in the channel, but also form a continuous vapor layer between the heating surface and the main flow liquid, resulting in a sharp increase in interfacial thermal resistance. Eventually, the system may enter a boiling crisis state in advance, causing the temperature of the heating surface to rise sharply, and even local dryout and thermal failure phenomena may occur. Therefore, in order to solve the problems of uneven flow distribution, early critical heat flux and abnormal temperature rise caused by the failure of bubbles to be discharged in time in the process of micro-channel flow boiling, it is urgent to develop a heat dissipation system that can realize rapid bubble detachment and efficient bubble discharge, so as to realize stable control of the flow boiling process and ensure the safe and reliable operation of high heat flux chips under high power working conditions. SUMMARY

[0004] Therefore, the application aims to provide a flow boiling multiphase flow heat transfer strengthening device based on a gas-philic degassing film and a working method, so as to solve the problems of uneven flow distribution, early critical heat flow and abnormal temperature rise caused by the failure of bubbles to be discharged in time in the flow boiling process of microchannels.

[0005] To achieve the above-mentioned purpose, the application adopts the following technical solutions: The flow boiling multiphase flow heat transfer strengthening device based on the gas-philic degassing film comprises an upper sample layer, a gas-philic degassing structure layer, a star-shaped gas-philic degassing structure, a lower sample layer, a rhombic needle-shaped rib, a sample inlet water collecting chamber, a vacuum negative pressure chamber and a sample outlet water collecting chamber, the gas-philic degassing structure layer is installed between the upper sample layer and the lower sample layer, a space formed between the left end of the upper sample layer and the lower sample layer is the sample inlet water collecting chamber, a space formed between the right end of the upper sample layer and the lower sample layer is the sample outlet water collecting chamber, a vacuum negative pressure area in the middle of the upper sample layer and the middle of the gas-philic degassing structure layer forms the vacuum negative pressure chamber, the star-shaped gas-philic degassing structure is arranged below the gas-philic degassing structure layer, the star-shaped gas-philic degassing structure and the rhombic needle-shaped rib installed on the surface of the lower sample layer are arranged in a staggered manner, the gas-philic degassing structure layer and the star-shaped gas-philic degassing structure are super gas-philic degassing films and have super gas-philic degassing capacity, a heating chip is installed below the outer surface of the lower sample layer, and the star-shaped gas-philic degassing structure is communicated with the vacuum negative pressure area.

[0006] Further, the star-shaped gas-philic degassing structure and the rhombic needle-shaped rib are arranged in a staggered manner.

[0007] Further, the surfaces of the gas-philic degassing structure layer and the star-shaped gas-philic degassing structure are treated by nano-particle coating or low surface energy modification.

[0008] Further, the gas-philic degassing structure layer and the star-shaped gas-philic degassing structure are made of gas-philic materials such as polytetrafluoroethylene, polypropylene or polyvinylidene fluoride.

[0009] Further, the surface of the star-shaped gas-philic degassing structure is provided with a micro-nano composite structure.

[0010] Further, the sample inlet water collecting chamber comprises a liquid inlet, a drainage inlet and a lower fluid inlet water collecting chamber which are communicated with each other, the liquid inlet is arranged at the left end of the upper sample layer, the left end of the gas-philic degassing structure layer is provided with the drainage inlet, and the lower fluid inlet water collecting chamber is arranged at the left end of the lower sample layer.

[0011] Further, the sample outlet water collecting chamber comprises a liquid outlet, a drainage outlet and a lower fluid outlet water collecting chamber which are communicated with each other, the right end of the gas-philic degassing structure layer is provided with the drainage outlet, the liquid outlet is arranged at the right end of the upper sample layer, and the lower fluid outlet water collecting chamber is arranged at the right end of the lower sample layer.

[0012] Further, the vacuum negative pressure chamber is connected with the vacuum system through the air outlet.

[0013] A working method of a flow boiling multiphase flow heat transfer strengthening device based on a gas-attracting degassing film, which comprises the following steps: Step 1: The cooling liquid enters the sample inlet water collecting chamber through the liquid inlet on the upper layer of the sample, and flows between the diamond needle-shaped ribs and the star-shaped gas-attracting degassing structure on the lower layer of the sample; Step 2: In the flowing process, after absorbing the heat generated by the heating chip, flow boiling occurs in the channel, gas bubbles are generated between the diamond needle-shaped ribs and rise, and are captured by the star-shaped gas-attracting degassing structure arranged in a staggered manner; Step 3: Vacuum treatment is performed through the vacuum system and the air outlet, so that the vacuum negative pressure chamber is in a vacuum state, and the gas bubbles are unidirectionally discharged through the star-shaped gas-attracting degassing structure and directly extracted through the vacuum system; Step 4: The heated liquid is discharged in turn through the lower fluid outlet water collecting chamber, the drainage outlet and the liquid outlet.

[0014] Compared with the prior art, the present application has the following beneficial effects: 1. The present application realizes a stable flow boiling heat transfer process of the heat dissipation sample by using the rapid bubble capture and gas permeability of the super gas-attracting degassing film.

[0015] 2. The present application changes the separation and discharge of the gas bubbles from the buoyancy and fluid flow control to the surface tension and negative pressure cooperative driving, so that the liquid can re-wet the heating surface in time after the gas bubbles are quickly removed, effectively preventing the gas film covering and local dryness phenomenon, thereby significantly improving the critical heat flux density and heat transfer stability.

[0016] 3. The present application realizes the directional capture and rapid extraction of the gas bubbles through the star-shaped gas-attracting degassing structure, and realizes the active regulation of the gas bubbles and the heat transfer cooperative strengthening in the flow boiling through the synergistic effect of the diamond needle-shaped ribs, the star-shaped gas-attracting degassing structure and the vacuum negative pressure chamber, thereby providing an efficient, stable and scalable solution for high-power device heat dissipation.

[0017] 4. The staggered arrangement of the diamond needle-shaped ribs and the star-shaped gas-attracting degassing structure can increase the heat exchange area and form local disturbance, thereby significantly improving the convective heat transfer coefficient.

[0018] 5. The rapid bubble separation of the present application effectively avoids the formation of gas film and flow blockage, so that the flow is more uniform and stable.

[0019] 6. The present application can be directly applied to a high heat flux electronic chip cooling system and has good manufacturability and engineering scalability. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein for explanation. The illustrative embodiments of the invention will be best understood by reference to the accompanying drawings, wherein: Fig. 1 An explosion structure schematic diagram of a flow boiling multiphase flow heat transfer enhancement device based on a gas-favoring degassing membrane according to the present application; Fig. 2 A structure schematic diagram of a flow boiling multiphase flow heat transfer enhancement device based on a gas-favoring degassing membrane according to the present application; Fig. 3 A schematic diagram of an interlaced star-shaped gas-favoring degassing structure and a rhombic needle-shaped rib according to the present application.

[0021] In the drawings: 1 - liquid inlet, 2 - air extraction port, 3 - liquid outlet, 4 - upper layer of sample, 5 - gas-favoring degassing structure layer, 6 - drainage inlet, 7 - vacuum negative pressure area, 8 - drainage outlet, 9 - star-shaped gas-favoring degassing structure, 10 - lower layer of sample, 11 - lower layer fluid inlet collection chamber, 12 - rhombic needle-shaped rib, 13 - lower layer fluid outlet collection chamber, 14 - sample inlet collection chamber, 15 - vacuum negative pressure chamber, 16 - sample outlet collection chamber. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0023] Specific implementation 1: see Figs. 1-3In this embodiment, a flow boiling multiphase flow heat transfer enhancement device based on gas affinity degassing film includes an upper sample layer 4, a gas affinity degassing structure layer 5, a star-shaped gas affinity degassing structure 9, a lower sample layer 10, a rhombic needle rib 12, a sample inlet water collecting chamber 14, a vacuum negative pressure chamber 15, and a sample outlet water collecting chamber 16. The gas affinity degassing structure layer 5 is installed between the upper sample layer 4 and the lower sample layer 10. The space formed between the left end of the upper sample layer 4 and the lower sample layer 10 is the sample inlet water collecting chamber 14. The space formed between the right end of the upper sample layer 4 and the lower sample layer 10 is the sample outlet water collecting chamber 16. The middle part of the upper sample layer 4 and the vacuum negative pressure area 7 of the middle part of the gas affinity degassing structure layer 5 form the vacuum negative pressure chamber 15. The star-shaped gas affinity degassing structure 9 is arranged below the gas affinity degassing structure layer 5. The star-shaped gas affinity degassing structure 9 and the rhombic needle rib 12 installed on the surface of the lower sample layer 10 are arranged alternately. The star-shaped gas affinity degassing structure 9 is a gas affinity degassing film. The heating chip is installed below the outer surface of the lower sample layer 10. The star-shaped gas affinity degassing structure 9 is in communication with the vacuum negative pressure area 7. The vacuum negative pressure chamber 15 is connected with the vacuum system through the air outlet 2. This structure realizes the complete channel layout of the inflow, heat transfer, degassing, and outflow of the cooling liquid.

[0024] In this embodiment, the sample inlet water collecting chamber 14 includes the liquid inlet 1, the drainage inlet 6, and the lower fluid inlet water collecting chamber 11 which are in communication with each other. The liquid inlet 1 is arranged at the left end of the upper sample layer 4. The left end of the gas affinity degassing structure layer 5 is provided with the drainage inlet 6. The lower fluid inlet water collecting chamber 11 is arranged at the left end of the lower sample layer 10. The cooling liquid enters from the liquid inlet 1, flows through the drainage inlet 6 into the lower fluid inlet water collecting chamber 11, and then flows in the rhombic needle rib 12 and the star-shaped gas affinity degassing structure 9.

[0025] In this embodiment, the sample outlet water collecting chamber 16 includes the liquid outlet 3, the drainage outlet 8, and the lower fluid outlet water collecting chamber 13 which are in communication with each other. The right end of the gas affinity degassing structure layer 5 is provided with the drainage outlet 8. The liquid outlet 3 is arranged at the right end of the upper sample layer 4. The lower fluid outlet water collecting chamber 13 is arranged at the right end of the lower sample layer 10. The liquid heated by the heating chip flows through the lower fluid outlet water collecting chamber 13, the drainage outlet 8, and then is discharged from the liquid outlet 3.

[0026] When the device is in operation, the cooling liquid enters the sample inlet chamber 14 through the liquid inlet 1 on the upper layer 4 of the sample, flows between the lower layer of the diamond needle ribs 12 and the star-shaped gas-philic degassing structure 9, absorbs the heat generated by the heating chip, and is collected in the sample outlet chamber 16 and discharged through the liquid outlet 3. When flow boiling occurs in the channel, bubbles are generated between the diamond needle ribs 12 and rise, and then are captured by the star-shaped gas-philic degassing structure 9. Under the action of vacuum negative pressure, the bubbles are unidirectionally extracted through the star-shaped gas-philic degassing structure 9, which realizes rapid separation and effective exhaust, thereby preventing bubbles from gathering and forming a gas film, and causing heat transfer deterioration.

[0027] Specific implementation 2: see Figs. 1-3 To illustrate this embodiment, the star-shaped gas-philic degassing structure 9 is staggered with the diamond needle ribs 12. In the device, the star-shaped gas-philic degassing structure 9 of the gas-philic degassing structure layer 5 is staggered with the diamond needle ribs 12 of the lower layer 10 of the sample. This can not only expand the heat exchange area, but also strengthen the fluid disturbance and destroy the thermal boundary layer to enhance heat transfer. The star-shaped gas-philic degassing structure 9 can effectively capture and guide the rising bubbles. Under the action of vacuum negative pressure, the bubbles are unidirectionally extracted through the degassing film. This structure can prevent bubbles from gathering and forming a continuous gas film, thereby avoiding heat transfer deterioration. After the bubbles are quickly removed, the liquid can quickly refill to the heating surface to realize rewetting, further improving the heat transfer stability and critical heat flux density.

[0028] Specific implementation 3: see Figs. 1-3 To illustrate this embodiment, the surface of the star-shaped gas-philic degassing structure 9 is coated with nanoparticles or treated by low surface energy modification to enhance the gas-philic property, which is used to realize rapid capture and guidance of bubbles. The back of the gas-philic degassing structure layer 5 is provided with a vacuum negative pressure area 7 to form a stable negative pressure environment and realize unidirectional exhaust of bubbles.

[0029] Specific implementation 4: see Figs. 1-3 To illustrate this embodiment, the star-shaped gas-philic degassing structure 9 is made of a gas-philic material such as polytetrafluoroethylene, polypropylene or polyvinylidene fluoride. The surface of the star-shaped gas-philic degassing structure 9 is provided with a micro-nano composite structure.

[0030] The star-shaped gas-philic degassing structure 9 is made of a hydrophobic material such as polytetrafluoroethylene, polypropylene or polyvinylidene fluoride. The surface of the star-shaped gas-philic degassing structure 9 is integrated with a micro-nano composite structure such as a hundred-micron conical or needle-shaped microstructure, and is coated with nanoparticles to enhance the gas-philic property, which realizes rapid capture and guidance of bubbles. After the structure is connected with the vacuum negative pressure chamber 15, a unidirectional gas channel can be formed to accelerate the bubble exhaust process and avoid local dryout caused by vapor film coverage, thereby improving the critical heat flux density and enhancing the overall heat transfer performance.

[0031] Specific implementation 5: see Figs. 1-3The application discloses a working method of a flow boiling multi-phase flow heat transfer intensifier based on a gas-attracting degassing film. Step 1: The cooling liquid enters the sample inlet collecting chamber 14 through the liquid inlet 1 on the upper layer 4 of the sample, and flows between the diamond needle-shaped ribs 12 and the star-shaped gas-attracting degassing structure 9 of the lower layer 10 of the sample; Step 2: In the flowing process, the flowing liquid absorbs the heat generated by the heating chip, flow boiling occurs in the channel, gas bubbles are generated between the diamond needle-shaped ribs 12 and rise, and the gas bubbles are captured by the star-shaped gas-attracting degassing structure 9 arranged in a staggered manner; Step 3: The vacuum system and the air outlet 2 are used for vacuumizing treatment, so that the vacuum negative pressure chamber 15 is in a vacuum state, under the action of the vacuum negative pressure, the gas bubbles are unidirectionally discharged through the star-shaped gas-attracting degassing structure 9, and the gas bubbles are directly extracted through the vacuum system; Step 4: The heated liquid is sequentially discharged through the lower fluid outlet collecting chamber 13, the drainage outlet 8 and the liquid outlet 3.

[0032] The specific embodiments of the application disclosed above are only used to help explain the application. The specific embodiments do not describe all the details, and the application is not limited to the specific embodiments. According to the content of the specification, many modifications and changes can be made. The specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that the persons skilled in the art can well understand and utilize the application.

Claims

1. A device for enhancing heat transfer in multiphase flow and boiling based on a hydrophilic degassing film, characterized in that: The sample includes an upper layer (4), a gas-loving degassing structure layer (5), a star-shaped gas-loving degassing structure (9), a lower layer (10), a rhomboid needle-like rib (12), a sample inlet water collection chamber (14), a vacuum negative pressure chamber (15), and a sample outlet water collection chamber (16). The gas-loving degassing structure layer (5) is installed between the upper layer (4) and the lower layer (10). The space formed between the left end of the upper layer (4) and the lower layer (10) is the sample inlet water collection chamber (14), and the space formed between the right end of the upper layer (4) and the lower layer (10) is the sample outlet water collection chamber (16). 6) The vacuum negative pressure zone (7) in the middle of the upper layer (4) of the sample and the middle of the gas-loving degassing structure layer (5) form a vacuum negative pressure chamber (15). A star-shaped gas-loving degassing structure (9) is provided below the gas-loving degassing structure layer (5). The star-shaped gas-loving degassing structure (9) and the rhomboid needle-shaped ribs (12) installed on the surface of the lower layer (10) of the sample are arranged alternately. The gas-loving degassing structure layer (5) and the star-shaped gas-loving degassing structure (9) are gas-loving degassing membranes. A heating chip is installed below the outer surface of the lower layer (10) of the sample. The star-shaped gas-loving degassing structure (9) is connected to the vacuum negative pressure zone (7).

2. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 1, is characterized in that: The star-shaped aerobic degassing structure (9) is interspersed with the rhomboid needle-like ribs (12).

3. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 2, is characterized in that: The surfaces of the aerophilic degassing structure layer (5) and the star-shaped aerophilic degassing structure (9) are coated with nanoparticles or modified with low surface energy.

4. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 2, is characterized in that: The hydroxyl degassing structure layer (5) and the star-shaped hydroxyl degassing structure (9) are made of polytetrafluoroethylene, polypropylene or polyvinylidene fluoride.

5. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling according to claim 2, characterized in that: The surface of the star-shaped aerophilic degassing structure (9) is provided with a micro-nano composite structure.

6. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 1, is characterized in that: The sample inlet water collection chamber (14) includes an inlet (1), a drainage inlet (6), and a lower fluid inlet water collection chamber (11) that are interconnected. The inlet (1) is located at the left end of the upper layer (4) of the sample, the drainage inlet (6) is located at the left end of the gas-loving degassing structure layer (5), and the lower fluid inlet water collection chamber (11) is located at the left end of the lower layer (10) of the sample.

7. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 1, is characterized in that: The sample outlet water collection chamber (16) includes an interconnected liquid outlet (3), a drainage outlet (8), and a lower fluid outlet water collection chamber (13). The right end of the aerobic degassing structure layer (5) is provided with a drainage outlet (8). The liquid outlet (3) is located at the right end of the upper layer (4) of the sample, and the lower fluid outlet water collection chamber (13) is located at the right end of the lower layer (10) of the sample.

8. The device for enhancing multiphase flow heat transfer based on a hydrophilic degassing film in fluidized bed boiling, as described in claim 1, is characterized in that: The vacuum negative pressure chamber (15) is connected to the vacuum system through the air extraction port (2).

9. A method for operating the flow boiling multiphase flow heat transfer enhancement device based on a hydrophilic degassing film as described in any one of claims 1-8, characterized in that: It includes the following steps: Step 1: Cooling liquid enters the sample inlet water collection chamber (14) through the liquid inlet (1) of the upper layer (4) of the sample, and flows between the rhomboid needle-shaped ribs (12) and the star-shaped gas-loving degassing structure (9) of the lower layer (10) of the sample; Step 2: During the flow, after absorbing the heat generated by the heating chip, the channel undergoes flow boiling. Bubbles are generated and rise between the rhomboid needle-shaped ribs (12) and are captured by the staggered star-shaped gas-loving degassing structure (9). Step 3: Vacuum treatment is performed through the vacuum system and the air extraction port (2) to make the vacuum negative pressure chamber (15) a vacuum state. Under the action of vacuum negative pressure, the bubbles are discharged unidirectionally through the star-shaped gas-loving degassing structure (9) and the bubbles are directly extracted through the vacuum system. Step 4: The heated liquid is discharged sequentially through the lower fluid outlet water collection chamber (13), the drainage outlet (8), and the liquid outlet (3).

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