50 results about "Boiling heat transfer" patented technology

The invention provides a multi-physics-field coupled core particle microchannel boiling heat exchange experiment testing device and testing method, and belongs to the field of boiling heat exchange experiment testing devices. According to the invention, a laser thermal control module, a reflection temperature measurement module, a particle velocity measurement module, a three-dimensional micro-control module, a stress test module, a sound field test module and an electric field test module are creatively integrated, and flexible combination and active control of each physical field are realized through standardized interfaces. Local point heating is achieved through pulse laser, non-contact transient surface temperature analysis is achieved through a heat reflection method, a micro-nano scale phase change flow field is analyzed through a PIV system, local thermal stress is measured through an embedded film strain gauge set, and automatic alignment and cooperative measurement of all modules are achieved in combination with a high-precision piezoelectric displacement table. Through modular design and system integration, accurate coupling and cooperative measurement of multiple physical fields of light, sound, heat, force and flow on the core particle scale are realized.

The present application relates to a kind of slab continuous casting high temperature casting blank surface temperature on-line detection method, belong to slab continuous casting technical field, comprising the following steps: S1: based on film temperature sensor production detection piece and measuring disc, and according to process requirement in corresponding two cooling zone sector segment clamp roll installation;S2: local transient heat conservation analysis is carried out to temperature measurement node, obtains the heat balance equation of considering conduction, convection and radiation heat transfer mode;S3: based on single node temperature time series discrete algorithm and according to temperature detection value, the heat balance equation is carried out numerical calculation, to reconstruct the actual temperature of the side above water film on slab surface is determined;S4: boiling heat transfer mechanism theory analysis is carried out, determines its corresponding critical characteristic temperature and the heat transfer mode where it is;S5: under stable film boiling heat transfer mechanism, according to classic flat plate temperature analytical theory, combined with the temperature of the side above water film on slab surface obtained again reconstruction calculation, to finally obtain the real temperature value of slab surface.

The invention discloses a heat transfer calculation method for pulsating heat pipes with adjustable inclination angles and liquid filling rates. The heat transfer performance of the pulsating heat pipes with different inclination angles and liquid filling rates is researched by adopting a numerical method; calculating the heat transfer process by solving the energy equation of the steam bomb and the energy and momentum equation of the liquid bomb, so as to predict the pulsation phenomenon of the working medium in the pulsating heat pipe; on the basis of a momentum heat mass transfer model, calculating the phase change heat transfer capacity through film condensation and a down-flow film boiling heat transfer coefficient, investigating the influence of different inclination angles on the liquid film thickness and the down-flow film speed, and increasing the influence of the down-flow film on the liquid elastic length; and the liquid bomb pulsation condition of the pulsating heat pipe under different inclination angles and different liquid filling rates is researched, and then the heat transfer performance of the pulsating heat pipe is calculated. The working heat transfer performance of the pulsating heat pipes with different inclination angles and liquid filling rates and the motion state of the working medium are analyzed and calculated, and guidance is provided for parameter development and engineering application of the pulsating heat pipes.

The invention discloses a single-sintering porous metal mold with different pore diameters for boiling heat exchange, and relates to the field of preparation equipment of porous metal for boiling heat exchange. The die comprises an outer die sleeve, a lower die base and three functional pressure heads, specifically, basic metal powder is compacted through a basic pressure head with a flat end face, then pore channels are pressed out through a pore-forming pressure head with thin cylindrical protrusions, finally, the pore channels are filled with powder with different particle sizes through a filling pressure head with matched through holes, and finally porous metal structures with different pore diameters are obtained through single-time sintering. The preparation process of porous metal with different pore diameters is simplified, the cost is reduced, pore collapse caused by secondary hole machining is avoided, and meanwhile the nucleation efficiency and the heat exchange performance of boiling heat exchange can be remarkably improved through the porous structures with different pore diameters.

This invention discloses a modular low-voltage switchgear suitable for smart grids, belonging to the field of low-voltage switchgear technology. It includes a cabinet with multiple module slots inside, each containing multiple auxiliary heat transfer components. Drawer units are installed within the module slots, and each drawer unit is equipped with a breathing heat dissipation unit. This invention replaces the rigid sealing structure with a multi-layer corrugated metal diaphragm assembly. It utilizes the corrugated elastic compression to absorb impact energy, automatically quenching flames through interlayer slits, and leverages the evaporation and condensation cycle of the phase change working fluid to achieve efficient heat conduction without occupying the internal installation space of the drawer unit. This solves the problem of limited heat dissipation capacity in explosion-proof switchgear. Furthermore, by mixing magnetic particles into the liquid phase change working fluid, the boundary layer is disturbed under the drive of the auxiliary heat transfer components, promoting bubble generation and detachment, significantly enhancing the nucleation boiling heat transfer coefficient.

The application discloses a high-flux heat exchange device based on a thermo-chemical reaction auxiliary, which comprises a heat exchange chamber and a chemical phase change working medium. The chemical phase change working medium comprises a liquid cooling base fluid and a reversible thermal decomposition solute. The thermal decomposition temperature threshold of the reversible thermal decomposition solute is lower than the physical boiling point of the liquid cooling base fluid under the current environment. When the temperature or pressure of the heat exchange surface reaches the thermal decomposition temperature threshold, the reversible thermal decomposition solute undergoes an endothermic decomposition reaction on the heat exchange surface, rapidly generates a large number of non-condensable bubbles and high-frequency separates, thereby triggering strong local micro-convection disturbance of the fluid and absorbing a large amount of chemical decomposition heat, and finally achieving heat dissipation of the heating element. The application accelerates the transfer of wall heat by using a thermo-chemical reaction, and improves the separation rate of bubbles at the solid-liquid interface, breaks the engineering resistance that bubbles are difficult to nucleate and efficiently separate in traditional boiling heat transfer, and realizes rapid and large absorption and transfer of the combined chemical reaction heat of the solute and the latent heat of vaporization of the base fluid.

The application provides a cooling method and system for electronic equipment. The method comprises: when the electronic equipment is working, controlling low-boiling cooling medium and high-boiling cooling medium to flow at respective initial mass flow rates; acquiring heat flow density and temperature signals of the electronic equipment in real time, and adjusting the mass flow rates of the low-boiling cooling medium and / or the high-boiling cooling medium in real time. The cooling system comprises an electronic module and a cooling channel, a temperature sensor and a controller located in the electronic module. The cooling channel comprises a first cooling channel and a second cooling channel, and the first cooling channel and the second cooling channel circulate cooling medium with different boiling points. The controller is used for controlling the on-off and mass flow rate of the cooling medium of the first cooling channel, and / or controlling the on-off and mass flow rate of the cooling medium of the second cooling channel. The system and method can solve the problems of instability and low reliability of traditional boiling heat transfer, and can meet the heat dissipation requirements of high heat flow density electronic modules.

This invention discloses a thermosiphon loop device. The evaporator consists of four parts: a liquid chamber, a vapor chamber, a microgroove structure, and a filter screen. The microgroove structure significantly increases the number of vaporization nuclei, enhancing boiling heat transfer. Above the microgroove structure, a hemispherical filter screen is designed to drastically reduce the amount of liquid carried into the vapor chamber, thereby enhancing gas-liquid separation within the evaporator. This gas-liquid separation allows the working fluid to have a higher dryness near the evaporation section outlet, significantly increasing the density difference and pressure driving force between the vapor and liquid phases inside the thermosiphon loop, and improving the heat transfer limit. Furthermore, a heat insulation device is installed in the condensate return pipe at the bottom of the evaporation section to suppress backflow caused by the growth and expansion of boiling bubbles, effectively reducing heat leakage at the bottom of the evaporation section. This invention achieves gas-liquid separation within the evaporator and reduces heat leakage at the bottom, thereby improving the heat transfer performance of the thermosiphon loop and making it suitable for high-power heat dissipation requirements.

The invention discloses a mixed wettability nanowire modified three-stage enhanced boiling heat transfer structure and a preparation method thereof, and belongs to the technical field of micro-nano processing and enhanced phase change heat transfer. According to the structure, two kinds of functional micro-column arrays, namely a micro-cylinder array modified by a super-hydrophilic nanowire and a micro-square column array modified by a super-hydrophobic nanowire, are integrated on a substrate. An efficient liquid supplementing channel is constructed through the strong capillary action, and local dryness is effectively inhibited; the latter is used as a low-superheat-degree nucleation site, rapid generation and separation of bubbles are promoted, bubble coalescence can be effectively inhibited through the millimeter-level spacing, and formation of a steam film is delayed. The two types of micro-columns are orderly distributed in space, and a bubble separation path and a liquid backflow channel are collaboratively optimized. The structure integrates the multi-scale enhanced boiling heat transfer advantages of the millimeter-scale hydrophobic nucleation interval, the micron-scale cylinder and the nano-scale linear structure, the heat transfer coefficient and the critical heat flux are improved, and the structure has important application potential in the high-heat flux heat dissipation fields of high-power electronic devices, aerospace, new energy equipment and the like.

The invention provides a construction method of a nucleation gradient multi-element structure spliced surface based on a femtosecond laser direct writing technology, and relates to the technical field of boiling heat transfer enhanced surface engineering. Femtosecond laser is adopted to conduct cross scanning on a metal substrate to prepare a dot matrix cavity with the automatic liquid supply capacity, and the opening size of the cavity and the bubble production behavior are controlled by adjusting the number of cross lines; preparing a laser-induced periodic structure LIPSS with different roughness on the external surface of the cavity so as to strengthen hydrophilicity; capillary grooves with low nucleation activity are processed in the center of a lattice grid to serve as gap channels, and gas-liquid channel separation and ordered bubble separation are achieved. The surface can cooperatively regulate and control the nucleation density, wettability and gas-liquid separation path, and meanwhile, the boiling heat transfer coefficient and the critical heat flux density are improved.

The application provides an aluminum vapor cavity liquid wick and a preparation method thereof, and relates to the technical field of electronic chip heat dissipation. The preparation method of the aluminum vapor cavity liquid wick comprises the following steps: preparing a porous MAO ceramic film layer on the surface of an aluminum base, significantly increasing the bubble nucleation site density and the corrosion resistance of the aluminum surface; loading FeCo nanoparticles on the surface of the porous MAO ceramic film layer through a self-assembly method, and enhancing the catalytic performance of the surface; and preparing a CNTs coating with a vertical FeCo CNTs array on the surface of the porous MAO ceramic film layer through a chemical vapor deposition method, so that the CNTs coating has the advantages of a high aspect ratio and small pores, the capillary wicking effect is increased, and liquid rewetting is promoted. The aluminum vapor cavity liquid wick with the FeCo CNTs / MAO composite coating on the surface of the aluminum base is prepared, and the composite coating can exert the advantages of the MAO layer and the CNTs coating, and synergistically enhance the heat transfer efficiency and the boiling heat transfer stability of the surface of the aluminum vapor cavity liquid wick.

The present disclosure provides a thin liquid film boiling heat transfer enhancement device, comprising: a vacuum cavity, a first mounting hole is opened in the bottom; an evaporation base is installed in the first mounting hole, and the upper surface of the evaporation base is higher than the inner bottom surface of the vacuum cavity, and the upper surface of the evaporation base is provided with a second mounting hole; a liquid dam is arranged on the upper surface of the evaporation base, a test hole with a predetermined size is arranged at the center of the liquid dam, and the size of the test hole is larger than that of the second mounting hole; an upper heating block is installed in the second mounting hole, and the upper surface of the upper heating block is located in the same horizontal plane as the upper surface of the evaporation base; a lower heating block is arranged in the evaporation base, and the lower heating block is sleeved on the bottom of the upper heating block; a spiral condensing pipe is arranged in the vacuum cavity, and the lower end of the spiral condensing pipe is spaced apart from the upper surface of the evaporation base by a predetermined distance; the centers of the spiral condensing pipe, the evaporation base, the liquid dam, the upper heating block and the lower heating block are located on the same straight line, and the straight line is perpendicular to the horizontal plane.

The invention relates to the technical field of heat dissipation of electronic devices, in particular to a dot matrix type super-hydrophilic-super-hydrophobic mixed wetting surface for strengthening boiling heat transfer and a preparation method of the dot matrix type super-hydrophilic-super-hydrophobic mixed wetting surface. According to the dot matrix type super-hydrophilic-super-hydrophobic mixed wetting surface, a super-hydrophilic surface with a CuO micro-nano sheet thorn structure is constructed and formed on the surface of a copper substrate through a chemical oxidation method, and a super-hydrophobic dot matrix surface is prepared on the super-hydrophilic surface by spraying a super-hydrophobic coating and used for increasing bubble nucleation sites and accelerating supply of liquid to the bubble nucleation sites, so that the number of bubble nucleation sites is increased. Bubble combination is inhibited; the super-hydrophobic dot matrix surface is obtained by discretely arranging hexagonal dot matrix units; the contact angle of the surface of the super-hydrophobic dot matrix is not less than 160 degrees; and the contact angle of the super-hydrophilic surface is 0-10 degrees. Hexagonal dot matrix units are discretely distributed on a super-hydrophilic surface of a CuO micro-nano sheet thorn structure to form a super-hydrophobic dot matrix surface; the technical problem that the boiling heat transfer coefficient and the critical heat flux of an existing boiling heat transfer surface are difficult to consider at the same time is solved.

The present invention provides a boiling heat transfer surface for a boiling cooler and a method for forming the same, which can improve cooling performance by quickly removing large bubbles from the heat transfer surface so that they do not become covered on the boiling heat transfer surface. [Solution] The boiling heat transfer surface of the boiling cooler receives heat from an external heating element and boils the internal liquid-phase coolant, causing it to change from liquid to vapor. The boiling heat transfer surface 1 is formed by bending the tip ends of a plurality of plate-shaped fins 3 that are formed standing upright in parallel at a predetermined distance from a metal substrate 2 and joining them to adjacent fins 3 to form cavities 4 between the fins 3. A plurality of small holes 5 are formed at predetermined distances from the upper end of adjacent cavities 4. The inner wall 3a on one side and the inner wall 3b on the other side of the cavity 4 are inclined toward the other side of the metal substrate 2, and the bottom surface 4a is formed as an inclined surface that gets higher from one side to the other. The small holes 5 are formed by grooves 51 formed on the tip side of the fins 3, and the tip side of the fins 3 is bent from a virtual bending line BL that connects the bottoms 51a of the plurality of grooves 51.

The utility model discloses a kind of heat exchange tube and reboiler, the heat exchange tube includes tube body and heat transfer layer, the heat transfer layer is located at the inner surface or outer surface of the tube body, the heat transfer layer is equipped with multiple helical grooves and helical protruding parts of alternate arrangement, each the helical protruding part is equipped with groove group on. The utility model its structure can effectively increase heat exchange area and enhance heat exchange effect. Meanwhile, the three-dimensional porous structure of the utility model significantly enhances boiling heat transfer, wherein the heat transfer layer includes multiple helical grooves and helical protruding parts of alternate arrangement, the groove group cooperation on the surface of the helical groove and the helical protruding part makes the rotating flow of the medium to be heated when flowing, enhances turbulence degree, realizes the promotion of heat transfer efficiency.

The application provides a kind of multi-physical field coupling core particle micro-channel boiling heat transfer experimental testing device and testing method, belongs to the field of boiling heat transfer experimental testing device.The application innovatively integrates laser heat control module, reflective temperature measurement module, particle velocity measurement module, three-dimensional micro-control module, stress test module, sound field test module and electric field test module, and realizes flexible combination and active control of each physical field through standardized interface.Pulse laser is used to realize local point heating, thermal reflection method is used to realize non-contact transient surface temperature analysis, PIV system is used to analyze micro-nano scale phase change flow field, and embedded thin film strain gauge group is used to measure local thermal stress, and high-precision piezoelectric displacement table is used to realize automatic alignment and collaborative measurement of each module.Through modular design and system integration, precise coupling and collaborative measurement of light, sound, heat, force and flow multi-physical fields on the core particle scale are realized.

The embodiment of the invention relates to the field of computer aided design using fluid dynamics, in particular to a development method of a nucleate boiling heat transfer calculation model. The method mainly comprises the following steps: respectively determining the wall temperature of a heating surface in a plurality of fully developed nucleate boiling heat transfer stages and the wall temperature of a heating surface in a part of underheated nucleate boiling heat transfer stages by obtaining heat transfer data; and finally determining a nucleate boiling heat transfer calculation model. According to the method, the nucleate boiling is divided into a partial underheated nucleate boiling section and a full development nucleate boiling section, and a nucleate boiling heat transfer calculation model is determined by respectively considering the wall temperatures of the heating surfaces of the partial underheated nucleate boiling section and the full development nucleate boiling section, so that the complete wall temperature distribution of heat transfer in different stages is accurately predicted.

The application discloses a hierarchical carbon nanomaterial film coating for enhancing boiling heat transfer and a preparation method thereof, and relates to the technical field of nanocoating enhanced phase change heat transfer. The film coating is completely coated on the surface of a target substrate and is composed of two different carbon nanomaterial film coatings A and B. The carbon nanomaterial film coating A is a graphene oxide laminated structure film coating which uniformly and continuously covers the surface of the target substrate. The carbon nanomaterial film coating B is a hydrophilic carbon nanotube nanoporous network structure film coating which covers the surface of the graphene oxide film coating in a discontinuous layout mode to form a plurality of uniformly distributed carbon nanotube film coating stripes, and a microscale channel structure is formed between the carbon nanotube film coating stripes. The hierarchical carbon nanomaterial film coating organically combines a plurality of micro-nanoscale characteristic structures and excellent properties, can produce a synergistic enhancement effect, greatly and synchronously improves CHF and HTC, and realizes a breakthrough in boiling heat transfer performance.

The application discloses a large-density-ratio two-phase boiling heat transfer simulation method based on a lattice Boltzmann algorithm, and comprises the following steps: solving corresponding pseudo-potentials according to densities and corresponding non-ideal state equations, calculating various forces in a multiphase system, and calculating source terms in a gas-liquid phase change model; calculating relaxation factors corresponding to different orders of moments in a multiphase flow field and a temperature field according to entropy stability conditions and specific properties of the fluid; substituting the calculated results into evolution equations of the multiphase flow field and the temperature field, and performing collision and migration according to the evolution equations; and calculating macro-physical quantities such as densities, velocities and temperatures at each lattice point according to density and temperature distribution functions, and judging whether iteration is ended or not. The application can effectively improve the two-phase density ratio in the simulation of gas-liquid boiling problems, realize the simulation of the phase change conversion process of water and water vapor under real conditions, and solve the simulation problem of complex multiphase flow and heat transfer.

The present invention provides a boiling-type heat transfer tube and a method for manufacturing a boiling-type heat transfer tube that can maintain a high heat transfer coefficient from the boiling-type heat transfer tube to the liquid refrigerant and achieve high heat transfer efficiency. [Solution] The boiling heat transfer tube is provided with multiple rows of fins 11 that protrude radially outward from the outer surface of the tube and are formed spirally along the central axis of the tube. Each fin 11 has a leg portion 11a and a pair of protruding portions 11b, 11c. A circumferentially continuous cavity 13 is defined between adjacent fins 11 in the direction of the tube axis. A recess 23 that is recessed in the direction of the tube axis is formed on the side wall surface 13b of the cavity 13, and a plurality of flat steps 17 are formed on the bottom surface 13a of the cavity 13, with extension pieces extending from the recess 23 being pressed against the bottom surface 13a.

This invention discloses a hydrophilic-hydrophobic heterogeneous structure and its preparation method for enhancing evaporation / boiling heat transfer, belonging to the field of surface modification for enhancing nucleate boiling heat transfer. This invention combines a hydrophilic capillary structure with a hydrophobic array column to obtain a hydrophilic-hydrophobic heterogeneous structure, promoting bubble escape, solving the backflow blockage effect, and enhancing boiling heat transfer. The heterogeneous structure prepared by this invention overcomes the problems of uncontrollable hydrophobic structure morphology and edge diffusion effects in the preparation of traditional hydrophilic / hydrophobic heterogeneous porous surfaces, while retaining the intrinsic pore size and structure of the hydrophilic / hydrophobic structure. It reduces the nucleate boiling initiation (ONB) in the early stage and simultaneously increases the critical heat flux (CHF) and heat transfer coefficient (HTC), possessing advantages such as high phase change heat transfer performance, simple processing technology, and low cost. It can provide excellent boiling heat transfer characteristics and is expected to be widely used in the field of boiling heat transfer.

The invention provides a visual pool boiling experiment device capable of realizing magnetic field regulation and control and an experiment method thereof, and belongs to the field of pool boiling experiment devices. The device mainly solves the problem that an existing device is difficult to apply a magnetic field in the experiment process. The device comprises a boiling cavity, a magnetic field control device, an auxiliary heating device, a heat flow generation device, a heat preservation device and a data acquisition device, an optical window is arranged on the boiling cavity, the auxiliary heating device maintains the temperature of a boiling working medium in the cavity, and temperature information is fed back in real time through a thermocouple fixed to the surface of a heat conduction rod. The magnetic field control device is used for applying different magnetic field conditions to the heat transfer surface in the boiling cavity in the boiling process. According to the invention, the magnetic field parameters applied in the boiling process can be adjusted, and the bubble behavior image in the boiling process is collected through the optical window. The invention aims to cooperate with the magnetic nanofluid to regulate and control the surface boiling heat transfer characteristic, so as to research the influence of different magnetic field parameters on the boiling heat transfer characteristic.

The invention belongs to the field of nuclear power reactor safety design in a marine environment, and particularly relates to a method and system for simulating three-phase contact line behaviors in a local deformation runner, and the system comprises a model building module which is used for building a multi-phase flow model coupled with multi-field force; the boundary processing module is used for processing local deformation wall surface and high-flow-speed outlet boundary conditions; and the simulation platform module is used for performing dynamic simulation and post-processing analysis and outputting key physical parameters. By constructing a special simulation platform, dynamic visualization and quantitative analysis of the whole process of formation and expansion of the dry spots in the narrow rectangular flow channel are realized for the first time, and a powerful scientific tool support is provided for revealing the internal mechanism of boiling heat transfer crisis from the mesoscale.

This invention discloses a porous grid composite structure for enhancing boiling heat transfer and its preparation method, belonging to the fields of composite structure surface development and enhanced boiling heat dissipation technology. The porous grid composite structure for enhancing boiling heat transfer consists of a lower layer of arrayed micro-concave holes and an upper layer of porous grid. The pore diameter of the upper layer of porous grid is smaller than that of the lower layer of micro-concave holes. The geometric constraints of the porous grid achieve a dynamic cycle mechanism of restricted growth, pressure penetration, and self-absorption rewetting: bubbles nucleate and grow within the micro-concave holes. Due to the restriction of the grid openings, the bubbles expand in a restricted manner within the concave holes until they penetrate the grid holes. The pressure difference generated at the moment of penetration drives the liquid to be rapidly drawn into the concave holes, causing direct contraction of the contact line and significantly reducing the bubble detachment diameter. Simultaneously, the gaps between the porous grids form a low-resistance continuous liquid flow channel, enhancing capillary transport capacity. Thus, a synergistic enhancement of small bubble detachment and efficient liquid recirculation is achieved, resulting in improved HTC and CHF, which can be used in pool boiling heat transfer applications.

This invention discloses an immersion liquid carbon dioxide cooling system and a data center cooling device. The system includes an immersion cold plate with a sealed cavity, an artificial intelligence chip assembly disposed within the cavity and fixed to a porous sintered material, a sealed upper cover plate, and an inlet and outlet pipe connecting the cavity. The chip assembly is at least partially immersed in liquid carbon dioxide flowing into the cavity, achieving cooling through boiling heat transfer of the liquid carbon dioxide on the chip surface. A coolant distribution unit manages the flow of liquid carbon dioxide and provides emergency protection. The data center cooling device stacks multiple immersion cold plates from the above system within a cabinet and connects them in parallel to a main distribution unit via manifolds. This invention utilizes the latent heat of phase change and non-conductive properties of liquid carbon dioxide to provide a chip cooling solution with high heat dissipation efficiency, strong adaptability, safety, reliability, and a compact structure, particularly suitable for cooling high-power-density artificial intelligence chips.

The present application discloses a surface structure for enhanced boiling heat transfer, comprising first channels for vapor bubble departure, micro-scale structures for promoting vapor bubble nucleation, and second channels for liquid suction. The aperture of the first channels is greater than the aperture of the second channels, the aperture of the second channels is greater than the width of the micro-scale structures, and there are a plurality of first channels, micro-scale structures, and second channels. In the surface structure for enhanced boiling heat transfer disclosed in the present application, the provision of the plurality of micro-scale structures can increase effective vapor bubble nucleation sites for boiling, thereby promoting the start of boiling. The provision of the plurality of first channels can provide low-resistance vapor flow channels, so that vapor bubbles can depart more quickly. The departure direction of vapor bubbles is consistent with the heat dissipation direction, thereby improving the heat transfer efficiency. The provision of the plurality of first channels separates vapor and liquid flows, minimizing interference between vapor bubble departure and liquid suction, thereby enhancing the heat transfer performance. The present application further discloses a method for manufacturing the surface structure for enhanced boiling heat transfer.

The present application relates to a kind of heat exchange tubes for evaporator, belong to evaporative heat exchange tube technical field, solve the single structure of the top of existing fin, the limited heat exchange area, the problem of insufficient number of vaporization core, including tube body and outer fin, outer fin is by the material on the tube body along the radial direction of the tube body and on the outer surface of the tube body around tube body and is formed into spiral state, the gap between adjacent two outer fins constitutes spiral channel, it further includes the secondary groove being cross-communicated with spiral channel, secondary groove extends along the axial direction of the tube body and with axial direction presents a certain angle, the outer fin is divided into several independent fin platforms by the secondary groove, the top end surface of the fin platform is provided with X-shaped channel being communicated with the secondary groove;With the X-shaped channel being set in the top of fin platform, can further increase the number of vaporization core, significantly improve the effect of boiling heat transfer coefficient outside tube.

The application discloses a gravity and micro-nano structure reinforced thermosyphon radiator and a preparation method thereof, and belongs to the field of thermosyphon radiators. The structure comprises a heat absorption end bottom plate, the top end of the heat absorption end bottom plate is provided with a heat dissipation mechanism, the heat dissipation mechanism is provided with a fixing mechanism on both sides and above, the heat absorption end bottom plate is in a box-shaped structure, the heat absorption end bottom plate is provided with positioning bolt holes at four corners, the heat absorption end bottom plate is internally provided with a heat absorption end supporting column and a heat absorption end inner wall surface reinforcing structure, and the box wall on one side of the heat absorption end bottom plate is provided with a suction and injection port. The application adopts the above structure and method, solves the problems that the steam diffusion direction of the current traditional thermosyphon pipe is single, the effective heat dissipation area is limited, the boiling heat transfer process of the smooth surface lacks vaporization cores, the re-wetting capacity is weak, and the heat transfer deterioration is advanced, and the problems that the heat dissipation demand of high heat flow chips cannot be met.

The invention discloses a CO2 transition boiling heat transfer experiment system and an experiment method thereof, and belongs to the technical field of phase change heat transfer test and measurement. An outlet of a water cooling machine is connected with a CO2 liquid storage tank through a back pressure valve; the thermal block shock cooling structure outside the experimental section pipeline comprises a solid thermal block covering the outer wall of the experimental section pipeline, a plurality of electric heating rods embedded into the solid thermal block and a plurality of thermocouples for measuring the temperature of the outer wall of the experimental section pipeline; one side of the solid thermal block is provided with through holes which penetrate from the outside to the outer wall of the experimental section pipeline along the axial direction at equal intervals, and a plurality of thermocouples are arranged in the through holes in a one-to-one correspondence manner; a pressure sensor and a temperature sensor are further arranged at the two ends of the experiment section pipeline respectively, the pressure sensor, the temperature sensor, the mass flow meter and the multiple thermocouples are all connected to a data collection system and used for monitoring and collecting experiment data, and measurement parameters can be accurately collected, and the transient heat flux density and the heat exchange coefficient of the inner wall can be obtained through calculation.

The invention discloses a boiling heat transfer enhanced cooling plate with complementary low guide holes and porous bodies and a cooler. The cooling plate comprises a plate body and a porous body; a plurality of low guide holes are formed in one side, close to the heat transfer surface, in the plate body in parallel, and each low guide hole is filled with a material with the heat conductivity coefficient lower than that of the plate body in a sealed mode; a plurality of porous bodies are arranged on the heat transfer surface of the plate body, the plurality of porous bodies and the plurality of low guide holes are arranged in a one-to-one correspondence manner, and each porous body corresponds to at least partial length of the corresponding low guide hole. According to the embodiment of the invention, regional temperature distribution can be formed on the heat transfer surface, in combination with regional distribution of the porous body, nucleation points are increased under the condition of medium and low heat flux to realize boiling heat transfer enhancement, and the heat transfer efficiency is improved by conveying liquid among the surfaces of different temperature zones under the condition of high heat flux. Particularly, liquid is supplied from liquid stored in the porous body to the smooth surface of the high-heat-conductivity material area, so that the appearance of critical heat flux density points is delayed, boiling heat transfer is enhanced, and higher heat transfer efficiency is achieved.