30results about How to "Improve boiling heat transfer capacity" patented technology

The invention discloses a flat-plate heat tube with a nanometer structure. The flat-plate heat tube with the nanometer structure comprises a bottom plate, a top plate and a supporting plate, wherein the supporting plate is positioned between the top plate and the bottom plate; the bottom plate, the top plate and the supporting plate are hermetically connected to one another to form a hollow closed cavity; a body of the bottom plate which serves as an evaporation surface of the flat-plate heat tube is a brass sheet; a copper oxide film which has a nanometer structure, has a super-hydrophilic property and is formed by electrochemical displacement covers the inner surface of the bottom plate; a body of the top plate which serves as a condensation surface of the flat-plate heat tube is a brass sheet; an electro-nickelling layer which has a nanometer structure and has a super-hydrophobic property covers the inner surface of the top plate; and small through holes are formed in a side surface of the supporting plate and are connected with capillary tubes. The evaporation surface and the condensation surface of the flat-plate heat tube are subjected to super-hydrophilic and super-hydrophobic surface modification, the evaporation speed and the condensation speed are increased, the heat exchange performance of an evaporation region and the heat exchange performance of a condensation region are improved, the thermal homogeneity is high, working medium is guided to return, and the working medium returning speed is increased, so that the whole heat exchange capability is improved.

The invention discloses a gravity assisted heat pipe device which comprises an evaporator, a heat insulation segment and a condenser. The evaporator and the condenser are in sealed connection with the heat insulation segment. The inner surface of the evaporator is a super-hydrophilic surface. The inner surface of the condenser is a smooth lubricant implanted porous surface (SLIPS). Lubricant on the SLIPS and a charged working medium cannot be mixed. A super-hydrophilic surface of a nano-micro structure is arranged on the inner wall of the evaporator, the working medium can completely moisten the wall face, a liquid film evaporates in the heating process, the evaporation intensity is improved, and the SLIPS of the condenser is formed by compounding the super-hydrophilic of a nano structure with implanted fluorine-containing lubricant or silicone oil or ionic liquid. Condensed liquid drops float on the SLIPS, are combined, fast fall off the SLIPS and sweep small liquid drops on the path of the condensed liquid drops, a condensation surface is provided for secondary condensation, and the condensation and heat exchange effect is remarkably improved. According to the gravity assisted heat pipe device, heat pipe heat resistance can be effectively reduced, the heat exchange performance of the device is improved, and wide application prospects are achieved.

The invention discloses a material surface micro-nano composite strengthening boiling structure as well as a preparation method and application of the material surface micro-nano composite strengthening boiling structure. The material surface micro-nano composite strengthening boiling structure comprises a base material and a micro-nano composite structure formed on the surface of the base material. The micro-nano composite structure comprises micro mastoids, communication-type grooves and nano-folds, wherein the micro mastoids are formed in the communication-type grooves, and the surfaces ofthe micro mastoids are provided with nano-fold shapes. The preparation method of the material surface micro-nano composite strengthening boiling structure comprises the following step of forming a micro-nano composite strengthening boiling structure on the base material through a laser integrated etching method. The material surface micro-nano composite strengthening boiling structure has multi-scale micron and nanometer characteristics in different levels.

The invention provides a chip integrated boiling enhancement heat exchange structure and a preparation method thereof based on an MEMS (Micro Electro Mechanical System) technology. The chip integratedboiling enhancement heat exchange structure comprises a heat conducting substrate, wherein a supporting layer is arranged on the surface of the heat conducting substrate; a plurality of claw type structures are arranged on the supporting layer; the claw type structures are obtained by preparing suspended metal sheet structures by adopting a surface micro-machining method, and folding the suspended metal sheet structures along plane normal thereof. According to the chip integrated boiling enhancement heat exchange structure disclosed by the invention, a path of combining and growing a large amount of surface bubbles into an air film is blocked off by the array claw type structures, so that the dry burning risk is avoided; porous structures can be prepared in the side walls of the claw typestructures so as to ensure liquid supply below the bubbles in the cavity and intensify the separating efficiency of the bubbles; the effects of increasing the heat exchange area by the claw type structures and further intensifying heat exchange by using bubble turbulence and convection of the metal side wall can be realized. Besides, the designed substrate material and a processing mode are derived from a chip integration technology, and application of the structure in integrated heat dissipation of electronic devices is favorably realized.

The invention discloses a multi-scale enhanced boiling surface and a composite preparation method thereof. Firstly, the nanoparticle coating is plated on the smooth surface of the metal or metal alloy by electrophoretic deposition. Subsequently, a honeycomb microstructure was generated on the surface of the nanoparticle coating by an electrochemical method. Thus, a multi-scale composite structure surface is prepared. The composite structure surface combines the advantages of two single preparation methods. On the one hand, it can provide more effective vaporization cores, and on the other hand, it can significantly improve the surface rehydration ability. Therefore, the composite structure surface can enhance the boiling heat transfer performance, including heat transfer coefficient and critical heat flux. For super-wetting fluids, such as FC‑72, HFE‑7200, NOVEC‑649, etc., the strengthening effect is also obvious. At the same time, the preparation method is mature, simple, and low-cost, which provides the possibility of its large-scale and industrial application.

The invention discloses a combined cylindrical chip reinforced boiling heat transfer microstructure and a manufacturing method thereof. The microstructure comprises a heat-dissipation plate arranged on the surface of a chip. The heat-dissipation plate is provided with a plurality of combination units. Each combination unit is formed by five microcolumns. The center of each combination unit is a cylindrical micro-column, and the rest four H-shaped micro-columns are arranged around the cylindrical micro-column symmetrically. The two surfaces of each H-shaped micro-column facing to the cylindrical micro-column and opposite to the cylindrical micro-column are the same parabolic surfaces, and the rest two sides surfaces and the top surface are planes; and every two adjacent combination units share one H-shaped micro-column. The microstructure can greatly increase the number of bubble evaporation cores, and greatly improve nucleate boiling heat transfer performance and critical heat flux density.

The invention belongs to the technical field of enhanced heat transfer, and provides a micro-scale collaborative surface structure for enhancing boiling heat transfer. The structure comprises a largegroove, a small groove, a connecting groove, a micro rib, a base surface and a super-hydrophobic coating; the base surface of the structure for enhancing boiling heat transfer is subjected to mechanical cutting, structure electroplating or laser burning to form a synergistic scale surface; the surface of the base surface is divided into the large groove, the small groove and the connecting groovethrough ribs. According to the structure, the micro-scale collaborative surface structure can achieve the capillary force effect, so that a liquid can reach a vaporization core point faster, the requirement of the boiling heat transfer vaporization process on the scale can be further met under the condition of different superheat degrees, the connecting groove between the large groove and the small groove enables liquid between the grooves to interact, so that steam is easier to discharge, and then the boiling heat transfer is enhanced.

The invention discloses a device and method for cooling partial high heat flow within a limited space. The device comprises a lower cover board, a water inlet pipeline, an inlet pipeline connector, a vacuum pumping port, an upper cover board, a supporting column, a containing space, a super-hydrophilic micro-nano structural coating, an evaporation area, a micro-channel tube bundle, an outlet pipeline connector, a water outlet pipeline, a partial heating source, a base board and a micro-channel hole. The micro-channel tube bundle is arranged in the condensation section space of an internal pipe of a guide panel heat pipe, so that the space of a whole cooler device is largely reduced. Due to the arrangement of micro-channel tubes, the cooling superficial area is enlarged, the coefficient of heat exchange is increased through forced convection of water in the micro-channel tubes, and the heat exchange capability of the condensation end is enhanced. The boiling heat exchange capability of the evaporation area is enhanced through the super-hydrophilic micro-nano structural coating, and finally the overall heat exchange capability of the device is enhanced.

The invention provides a porous surface boiling heat exchange enhancement device and a method for manufacturing the same. The porous surface boiling heat exchange enhancement device comprises a heat exchange enhancement device body, a plurality of heat dissipation grooves and a plurality of micro-fins. The heat dissipation grooves are formed in the outer surface of the heat exchange enhancement device body; the corresponding micro-fins are separated from one another, are positioned between each two rows of heat dissipation grooves and are made of shape memory alloy materials, and each micro-fin can be in two states after being trained; the micro-fins in the first states are oblique at the temperature lower than a preset temperature, and cover the upper portions of the heat dissipation grooves, and the heat dissipation grooves are converted into porous grooves; the micro-fins in the second states are tilted at the temperature higher than the preset temperature, the upper portions of the heat dissipation grooves are opened completely or partially, and the heat dissipation grooves are converted into open grooves. The porous surface boiling heat exchange enhancement device and the method have the advantages that the energy utilization efficiency can be improved, the temperature of a heating device can be low under the control of the porous surface boiling heat exchange enhancement device, and the stability and the reliability of equipment can be improved.

The invention relates to a nonuniform wetted surface with a fractal characteristic and a preparation method thereof. The nonuniform wetted surface comprises hydrophobic lattice areas and hydrophilic channels, wherein the hydrophobic lattice areas are distributed according to the fractal characteristic of a Sierpinski carpet curve, and the hydrophilic channels are staggered and pass through the hydrophobic lattice areas so as to form the nonuniform wetted surface. Hydrophobic lattices are distributed according to the fractal characteristic of the Sierpinski carpet curve, so that the boiling heat transfer coefficient is increased, additionally, the nucleating point and the moving and merging direction of steam bubbles can be planned, and the heat flux distribution characteristic in an electronic chip cooling process is combined, so that the forming of the steam bubbles in the high-heat flux density area in the center of a chip and the boiling heat exchange are effectively promoted. The hydrophilic channels can supply sufficient liquid working media, so that the steam bubble film forming is delayed, and the critical heat flux density is increased. The surface has the advantages of high critical heat flux density of hydrophilic areas and high boiling heat transfer coefficient of hydrophobic areas, and the consistent steam bubble distribution and heat flux density distribution of acooling surface can be realized, so that the boiling heat exchange is further intensified.

A liquid chamber heat dissipation device based on pool boiling heat dissipation includes a liquid chamber and an external heat dissipation device. The liquid chamber is composed of a bottom plate of the liquid chamber, a top plate of the liquid chamber and a heat dissipation pipe, and is filled with a phase change working fluid. The liquid phase-change working fluid absorbs the heat at the bottom of the boiling zone and undergoes boiling heat exchange to generate steam. The steam rises to the heat dissipation pipe through the through hole on the top plate of the liquid chamber, and is condensed into liquid by means of an air-cooled or water-cooled external heat sink and flows back into the liquid chamber. The compensation chamber and the liquid delivery area can effectively supply the phase change working medium to the boiling area. The invention adopts the heat exchange method of pool boiling and has strong heat dissipation capability. Compared with existing radiators designed based on steam chambers such as vapor chambers, it does not require a capillary core structure, is easy to process, and can effectively prevent internal evaporation while having a thinner thickness. It is suitable for heat dissipation of high-power heating equipment.

The invention discloses a spray cooling device combining a steam cavity and a composite microstructure. The device comprises a spray chamber, a spray chamber liquid inlet pipe, a spray chamber liquidoutlet pipe and a steam chamber, wherein the spray chamber and the steam chamber are integrally arranged; the spray chamber comprises a spray orifice plate, array nozzles and a composite microstructure which are positioned in the spray chamber; the spray orifice plate divides the spray chamber into a buffer chamber and a spray chamber; the spray chamber liquid inlet pipe is communicated with the buffer chamber; the spray chamber liquid outlet pipe is communicated with the spray chamber, the composite microstructure is arranged on the wall face, opposite to the array nozzle, in the spray chamber, the composite microstructure comprises a bottom layer liquid absorption core arranged on the wall face opposite to the array nozzle and a plurality of rib-shaped liquid absorption cores arranged onthe bottom layer liquid absorption core, and a phase change working medium is sealed in the steam chamber. The steam chamber expands heat generated by a heat source to the spraying wall face with a large area, the heat exchange performance of the wall face is improved through multi-nozzle array spraying, and the two-phase heat exchange capacity of spraying is improved through combination of the steam chamber and a composite microstructure enhanced heat transfer mode.

The invention discloses a partitioned block type strengthened boiling heat exchange microstructure and a manufacturing method thereof. The heat exchange microstructure comprises a radiating plate, wherein a plurality of circular block units are arranged on the radiating plate, each block unit is composed of a plurality of circles of microcolumns, and the block units are distributed on the radiating plate in an array mode. On the one hand, space distances between gas columns and the radius of the gas columns when heat flux is high can be limited, the merging among the gas columns is prevented,the boiling heat exchange performance of a high heat flux area is remarkably enhanced, and critical heat flux of chip boiling heat exchange is greatly improved; and on the other hand, each block unitis formed by the circular microcolumns which are arranged in a concentric circle, and microcolumn space distances from inner rings to outer rings are sequentially increased, so that flow resistance that fluid is directionally conveyed to a microstructure area from a smooth area is reduced, fresh liquid is timely supplied to the bottom of the of a bubble center under the condition of the high heatflux, the bubble evaporation is maintained, and the critical heat flux is further improved.