70results about How to "Reduce backflow resistance" patented technology

The invention discloses a fiber sintering type micro heat pipe and a manufacturing method thereof. The fiber sintering type micro heat pipe consists of a base pipe, a liquid suction core and a liquid working medium, wherein the liquid suction core is formed by solid-phase sintering for metal fibers. The manufacturing method for the fiber sintering type micro heat pipe mainly comprises four steps, namely preparation for the base pipe, processing of the metal fibers, manufacturing of the liquid suction core and precise encapsulation for the liquid suction core. After the metal fibers are sintered, metallurgical bonding is realized among the fibers and a large quantity of multi-scale pore structures are formed. The fiber sintering type micro heat pipe manufactured by using the method has the advantages of simple process, low cost, high porosity and controllability of the liquid suction core, high permeability, small liquid reflux resistance, large specific surface area of a metal fiber sintering layer, high capillary force and the like, and a stable three-dimensional meshed porous structure is formed among the fibers, so the fiber sintering type micro heat pipe is difficult to damage.

The invention relates to a sintered heat tube, which comprises a metallic tube. Wherein, the inner wall of tube has porous capillary structure formed by sinter powder; the porous capillary structure has several layers along the radius of heat tube, while each layer has several sections along the axle of heat tube; said capillary structure is formed by embedding different powder particles into the tube, using core rod as the control of thickness to be sintered on the inner wall. Said porous capillary structure can realize variable three-dimensional grade porous size and supply lower reflux resistance and improved capillary function, to improve the property of heat tube.

The invention discloses a micro-crack flat heat pipe and a manufacturing method thereof. The micro-crack flat heat pipe comprises a pipe body and a porous capillary layer attached to an inner wall of the pipe body, wherein a plurality of slots are arranged on the surface of the porous capillary layer and are uniformly distributed along the circumference of the inner wall of the pipe body. The manufacturing method comprises the following steps: placing a sintered core bar on the middle part in the pipe body and arranging a clearance between the pipe body and the sintered core bar; contracting the tail at one end of the pipe body and then performing de-rusting and de-oiling treatment on the pipe body and the sintered core bar; filling metal powder into the clearance between the pipe body and the sintered core bar and placing the metal powder together with the pipe body into a high-temperature sintering furnace for sintering; after sintering, taking out the pipe body, cooling to room temperature and then taking out the sintered core bar; vacuumizing, filling a working medium and sealing at the other end of the pipe body; and flattening and shaping the pipe body. A phase-change flattening technology is adopted by the invention; a continuous and big enough porous capillary layer, namely, a micro-crack channel space, is obtained according to a sintered core bar inducing method; a steam channel is supplied; and the heat transfer and mass transfer properties of the flat heat pipe are obviously increased.

The invention discloses a flat heat pipe liquid suction core provided with fins and embedded grooves and a manufacturing method thereof. The flat heat pipe liquid suction core comprises a metal evaporation plate, wherein multiple first embedded grooves and multiple second embedded grooves which are arranged at intervals and distributed in a staggered mode in the first direction and the second direction and multiple fins distributed in an array mode are arranged on the evaporation face of the metal evaporation plate, and each first embedded groove and each second embedded groove respectively comprises a groove body forming a groove cavity and a vertical gap forming a groove opening. Each fin comprises a fin body and a supporting boss and is formed by the gaps and internal groove bodies of the corresponding first embedded groove and the corresponding second embedded groove in a staggered mode. The liquid suction core can increase heat exchange area, promote boiling for nucleus formation, enhance boiling heat transfer, improve capillary pressure and reduce backflow resistance. During manufacture, a ball-end milling cutter is utilized to mill the embedded grooves in the first direction, and a base plate is turned to mill the embedded grooves in the second direction and meanwhile form a fin structure. The flat heat pipe liquid suction core is simple in manufacturing process and low in machining cost and can remarkably strengthen heat transfer.

The invention discloses a hot metal high-temperature heat pipe. The hot metal high-temperature heat pipe comprises a liquid filling pipe, a top end cover, a heat pipe shell, a bottom end cover, a gap,a condensation section liquid absorbing core, a heat insulation section liquid absorbing core, an evaporation section liquid absorbing core, a steam cavity, a liquid absorbing core plug and a gas storage bag. The closed liquid filling pipe, the top end cover, the heat pipe shell and the bottom end cover jointly form a closed space of the heat pipe. The liquid filling pipe is connected with a hotmetal filling loop through a connecting element, and filling of a working medium is achieved. The backflow resistance of the liquid working medium can be reduced through the gap. The evaporation section liquid absorbing core, the heat insulation section liquid absorbing core and the condensation section liquid absorbing core jointly provide power for backflow of the liquid working medium. The wavestructure of the heat insulation section liquid absorbing core can reduce liquid drop entrainment, and the condensation section liquid absorbing core adopts a fin structure to accelerate steam condensation. The liquid absorbing core plug can store the working medium and adjust the mass of the working medium participating in circulation. The gas storage bag can limit non-condensable gas, and the influence of the non-condensable gas on heat transfer is reduced.

The invention relates to an ultra-thin flat heat pipe and a manufacturing method thereof. A wick comprises a porous medium bottom layer and a plurality of porous medium filaments arranged side by side; the porous medium filaments make contact with the top of a tube shell; the wick inside the heat pipe, a sharp angled area between the porous medium filaments and the upper surface of the tube shell, and a sharp angled area between the porous medium filaments and the porous medium bottom layer provide liquid return capillary driving force which is large enough in a limited space; spaces formed between the porous medium filaments provide steam flow channels, and the steam flow channels communicate with one another; and reasonable matching of vapor-liquid phase distribution is achieved, and steam and condensed liquid can flow easily. According to the ultra-thin flat heat pipe, efficient operation can be maintained at various angles, the performance of anti-gravity operation is excellent, the heat flux which can be borne by the heat pipe is high, and the heat transfer performance of the heat pipe is remarkably improved after further modification treatment.

The invention relates to a heat pipe, which comprises a vaporizing section and a condensing section, which have different capillary structures, and the capillary structure of vaporizing section has smaller effective capillary holes, to generate small reflux resistance of condensed liquid in the condensing section, and generate large capillary function force on the liquid at the vaporizing section, to accelerate the reflux of condensing liquid from the condensing section to the vaporizing section. And the capillary structure of vaporizing section has smaller space to increase the contact area, to apply the heat transmission between the outer heat resource and the tube.

The invention relates to a temperature-uniforming plate, comprising a vacuum cavity, a working fluid, a lower capillary structure and a plurality of support pillars, wherein the vacuum cavity comprises an upper cover and a bottom plate and is filled with a proper amount of working fluid; the lower capillary structure is arranged on the bottom plate; the support pillars are positioned in the vacuumcavity and are connected with the upper cover and the bottom plate to support the upper cover; a first inclined angle is formed between each support pillar and the upper cover; and after being condensed, the vaporous working fluid flows back to the bottom plate through the support pillars from the upper cover.

The invention discloses a hot plate of metal fiber felt liquid absorption cores, and belongs to the technical field of heat exchange equipment using a middle heat transfer medium or a middle heat transfer body. The hot plate comprises a sealed shell body, a first metal fiber felt liquid absorption core, a second metal fiber felt liquid absorption core, a supporting frame and heat conduction liquid working medium. The supporting frame, the first metal fiber felt liquid absorption core and the second metal fiber felt liquid absorption core are installed in the sealed shell body. The heat conduction liquid working medium is filled in the sealed shell body. Compared with the prior art, the hot plate has the advantages that the metal fiber felt liquid absorption cores have good capillary force and permeability, combination strength and contact areas between fibers are increased, large quantities of three-dimensional net-shaped porous structures are formed among the fibers, the porosity is high, specific areas are large, liquid backflow resistance is little, the backflow speed of the liquid working medium in the hot plate is beneficially improved, and therefore heat dissipation performance of the hot plate is improved.

The invention discloses an ultrathin heat pipe. The ultrathin heat pipe comprises a metal pipe body, a liquid sucking core and a working medium; the wall thickness of the metal pipe body is 0.03-0.10 mm; the tail part and the head part of the metal pipe body are both sealing ends; the metal pipe body is a flat metal pipe body with a closed inner cavity; the liquid sucking core is arranged in the closed inner cavity of the metal pipe body; the liquid sucking core is a metal powder sintering capillary layer formed by bonding metal powder on the inner wall of the metal pipe body after high-temperature sintering; and the closed inner cavity of the metal pipe body is filled with the working medium. The invention further discloses a manufacturing method of the ultrathin heat pipe. The ultrathin heat pipe has the characteristics of smooth gas-liquid channel separation, good heat transfer performance, high capillary force and low backflow resistance of the working medium. The manufacturing method has the characteristics of convenience in operation of process steps, high production efficiency and adaption to large-batch production, and can effectively prevent drapes and recesses formed in the manufacturing process of the ultrathin heat pipe.

The present invention relates to a heat pipe porous stracture, including silk screen which is made up by using silk yarn through a certain knitting process. Said porous structure has pores with different apertures, and said pore sizes are formed into gradient distribution along the radial direction or longitudinal direction of heat pipe. The manufacture method of said heat pipe porous structure includes the following steps: rolling the above-mentioned flake silk screen with different pores into cylindrical silk screen, then placing the cylindrical silk screen into pipe body of heat pipe.

The invention relates to the field of heat pipe structures, in particular to an ultra-thin heat pipe. The ultra-thin heat pipe comprises a pipe body, wherein the pipe body comprises a middle side wall and end portion side walls connected with the middle side wall, the inner wall of the middle side wall is provided with a metal powder sintering portion, the side, away from the middle side wall, of the metal powder sintering portion is provided with a plurality of evenly distributed protrusions, and steam channels are formed among the metal powder sintering portion, the protrusions, the middle side wall and the end portion side walls. The metal powder sintering portion is provided with the protrusions which are intermittently or continuously arranged, a groove is formed between every two adjacent protrusions, the groove-shaped fluid return channels are formed in the spaces formed by the grooves and the middle side wall, axial heat transferring ability of the heat pipe is effectively reinforced, additionally, due to arrangement of the protrusions, the porosity is increased, fluid return resistance in the heat pipe is reduced, heat transferring efficiency is improved, heat conductive performance of the heat pipe is reinforced, and meanwhile, materials and production cost are saved.

The invention relates to a combined exterior structural heat pipe for vertical heat-pipe condensers. The combined exterior structural heat pipe for vertical heat-pipe condensers comprises a pipe body including a condensing segment and an evaporating segment. An exterior fin structure is arranged outside the pipe body, corresponding to the condensing segment, and an exterior grooved structure is arranged outside the pipe body, corresponding to the evaporating segment. The invention further relates to a manufacturing method of the combined exterior structural heat pipe for vertical heat-pipe condensers. The method includes the steps: manufacturing of the pipe body, manufacturing of an exterior fin unit, an upper end cover and a lower end cover, manufacturing of the exterior fin structure, and manufacturing and packaging of an absorbent core. The combined exterior structural heat pipe for vertical heat-pipe condensers and the manufacturing method thereof have the advantages that manufacturing process is simple and reliable, the combined exterior structural heat pipe provides a vertical heat-pipe condenser with good condensing effect and maintenance simplicity, and the combined exterior structural heat pipe and the manufacturing method thereof belong to the technical field of parts for condensers.

The invention relates to the technical field of uniform-temperature boards, in particular to an ultra-thin uniform-temperature board laser preparation method. The ultra-thin uniform-temperature board laser preparation method comprises the following steps that (1) pretreatment is conducted, specifically, substrates are cleaned; (2) grooves are prepared, specifically, the grooves are formed in the surfaces of the substrates through laser engraving; (3) the substrates are subjected to surface hydrophilic treatment; (4) welding forming is conducted, specifically, the groove faces of the two substrates are oppositely placed and subjected to laser welding, an inflation opening is reserved, and a formed uniform-temperature board is prepared; and (5) sealing is conducted through welding, specifically, the formed uniform-temperature board is filled with working media and sealed through welding. By adoption of the ultra-thin uniform-temperature board laser preparation method, the engraved grooves are neat and small, and the groove faces of the substrates are subjected to surface hydrophilic treatment, so that evaporation heat absorption and reflux condensation of the working media in the uniform-temperature board are facilitated; and meanwhile, the peripheries of the substrates are subjected to scale laser welding, the welding airtightness is good, and prepared heat pipe clamps are small in size, good in heat transfer performance and small in reflux resistance.

The invention discloses a gas-liquid separation device for enhancing self-absorption of a self-absorption type multistage centrifugal pump. The gas-liquid separation device is arranged inside a self-absorption centrifugal pump and mainly comprises two parts, namely an annular bracket and an annular spiral channel which is arranged close to the annular bracket, and the surface of the spiral channelis uniformly coated with a hydrophobic material to form the hydrophobic surface annular spiral pipe channel supported by the annular bracket. The gas-liquid separation device is installed between a cavity of a pump shell and the pump shell, an inner ring and an outer ring of the device are tightly attached to the cavity and the pump shell respectively, fan-shaped openings are formed in the bottomand the top of the gas-liquid separation device, the opening at the top is an exhaust port, and the opening at the bottom is a water return port. The gas-liquid separation device is installed in an area near a pump outlet, the exhaust port of the gas-liquid separation device is directly opposite to the pump outlet, and the water return port is located in the bottom of the pump. The annular gas-liquid separation device is simple in structure, convenient to install, low in machining difficulty, light in mass, easy in raw material obtaining and wide in application prospect.

The invention discloses a free particle / porous medium composite enhanced boiling structure. The structure comprises a substrate and a porous matrix structure formed on the surface of the substrate, aplurality of pore cavities are formed in the porous matrix structure, and free particles capable of moving in the pore cavity are dispersed in the pore cavity. When the free particle / porous medium composite enhanced boiling structure is prepared, metal particles are sintered to prepare a porous material matrix, the porous material matrix is drilled to form the pore cavity, and then the pore cavityis filled with free particles and sealed. The structure is based on the enhancing characteristics of nucleation activation in the boiling heat transfer process and liquid supply of a liquid absorbingcore to a nucleation site, bubbles are prevented from being mixed and the liquid backflow resistance is reduced by means of bubble nucleation and liquid supply partition. Meanwhile, the free particles collide with one another in the boiling process, so that heat transfer, microlayer evaporation and convective heat transfer in working fluid are enhanced, bubble nucleation is easy, the growth speedis high, the separation frequency is high, and therefore the enhanced boiling heat transfer is realized.

The invention discloses a composite liquid absorption core for a loop heat pipe. The composite liquid absorption core for the loop heat pipe is composed of metal powder, small phase-change balls and holes, wherein the diameter of the metal powder is 25-150 micrometers; each small phase-change ball is composed of a small phase-change ball outer shell and phase-change materials in the outer shell, the diameter of the small phase-change balls is 1-3 mm, and the solid-liquid phase-change temperature of the phase-change materials is 3 DEG C lower than the boiling point of work medium in the loop heat pipe; the size of the holes is realized by controlling the proportion of the metal powder with different particle diameters and the small phase-change balls. The composite liquid absorption core for the loop heat pipe can effectively avoid starting failure of the loop heat pipe caused by heat leakage of an evaporator shell body and the backward heat conduction effect of the liquid absorption core in the initial starting period of the loop heat pipe, facilitates smooth starting of the loop heat pipe and improves the operation stability of the loop heat pipe.

The invention discloses a method for manufacturing a miniature heat pipe by employing ultrathin foamed silver as a wick. The method is similar to conventional sintering of a copper heat pipe, and is characterized the ultrathin foamed silver is employed to replace a copper powder or silver powder sintered structure and serves as the wick, and the method is used for manufacturing a heat pipe by employing the ultrathin foamed silver as the wick, and the ultrathin foamed silver with a required porosity is manufactured through processes such as high temperature sintering and the like. The miniature heat pipe is generally prepared by the direct sintering of copper powder, and the porosity of the sintered copper wick is generally 40-50%. The porosity of the wick of the heat pipe prepared by the ultrathin foamed silver is up to 60-90%, and the porosity can be designed as needed. The ultrathin foamed silver has good capillary attraction and uniform hierarchy construction, and is high in porosity and thermal conductivity, the phase transformation cycling speed of the liquid medium is increased, the thermal resistance of the heat pipe is reduced, and the heat dissipation efficiency is obviously reduced. The method for manufacturing the miniature heat pipe by employing the ultrathin foamed silver as the wick is simple, the production process is pollution-free, the demand that a high heating flux electronic device is high in thermal conductivity and is miniaturized can be satisfied, and due to the price, the above manufacturing method is suitable for heat management of high-end equipment.

The invention discloses a loop heat pipe heat-conducting component. The loop heat pipe heat-conducting component mainly comprises an evaporator housing and an outer pipe, wherein the outer pipe is connected to the evaporator housing, so that the outer pipe and the evaporator housing form a loop; a copper powder-sintered capillary structure is arranged in the evaporator housing; and an exhaust hole is formed in one end of the copper powder-sintered capillary structure. The loop heat pipe heat-conducting component further comprises a capillary structure composed of heat-insulation fibers, wherein one side of the copper powder-sintered capillary structure is fixed, and other space in the evaporator housing is filled with the capillary structure composed of the heat-insulation fibers. According to the loop heat pipe heat-conducting component disclosed by the invention, due to the existence of the capillary structure composed of the heat-insulation fibers, a liquid flowing in the evaporator housing is absorbed by the capillary structure composed of the heat-insulation fibers and prevented from contacting with the evaporator housing, so that the heated-vaporized amount of the liquid is reduced, and then a pressure of an evaporation section is reduced, backflow resistance of a condensate is reduced, and heat-conducting efficiency is increased.

The invention discloses a preforming device for a compound liquid-absorbing core for a heat pipe. The preforming device comprises a ceramic ball, a supporting frame made of an aluminum profile or steel, a plurality of positioning plates sequentially fixed to the supporting frame from top to bottom and a heat pipe casing vertically fixed to the positioning plates. A core pipe arranged in the heat pipe casing in a vertical penetrating mode is coaxially arranged, the two ends of the heat pipe casing are provided with detachable end covers, the pipe wall of the core pipe is axially provided with a notch, and the diameter of the ceramic ball is larger than the internal diameter of the core pipe. The invention further provides the compound liquid-absorbing core for the heat pipe and a preparation method thereof. The preforming device is simple in structure and convenient to operate. According to the method for preparing the compound liquid-absorbing core for the heat pipe, radial compaction of the compound liquid-absorbing core can be implemented, it is ensured that the compound liquid-absorbing core and the pipe casing are effectively sintered, and contact thermal resistance is reduced. The prepared compound liquid-absorbing core for the heat pipe is excellent in heat transfer performance, high in permeability, large in capillary force, excellent in antigravity performance, low in cost and suitable for industrial scale production.

The invention discloses an asbestos-nonmetallic fibrofelt wick heat plate, belonging to the technical field of heat exchange equipment using an intermediate heat transfer medium or intermediate heat transfer body. The asbestos-nonmetallic fibrofelt wick heat plate disclosed by the invention comprises a sealing shell, a first nonmetallic fibrofelt wick, a second nonmetallic fibrofelt wick, a supporting frame and a heat-conducting liquid working medium, wherein the supporting frame, the first nonmetallic fibrofelt wick and the second nonmetallic fibrofelt wick are mounted inside the sealing shell, and the interior of the sealing shell is filled with the heat-conducting liquid working medium. Compared with the prior art, the asbestos-nonmetallic fibrofelt wick heat plate has the advantages that the nonmetallic fibrofelt wicks have relatively good capillary force and permeability, so that the bonding strength and contact area among fibers are increased; a large number of three-dimensional reticulated porous structures are formed among the fibers, so that the porosity is high, the specific area is large, and the liquid reflux resistance is low; the increase of reflux speed of the liquid working medium in the heat plate is facilitated, and then, the heat dissipating performance of the heat plate is improved.

The invention provides two methods for manufacturing a novel multi-scale flat aluminum belt heat pipe. The first method comprises the steps that S1, a flat aluminum belt heat pipe extrusion die is opened; S2, surface roughening treatment is conducted on the flat aluminum belt heat pipe extrusion die; and S3, extrusion forming is completed at a time through the extrusion die subjected to surface roughening, and the flat aluminum belt heat pipe with multi-scale micro grooves is obtained. The second method comprises the steps that S1, a flat aluminum belt heat pipe extrusion die is opened; S2, extrusion forming is conducted at a time through the extrusion die, and the flat aluminum belt heat pipe is obtained; and S3, secondary broaching is conducted on the flat aluminum belt heat pipe which is obtained through extrusion forming at a time, and the flat aluminum belt heat pipe with multi-scale micro grooves is obtained. The capillary suction force is improved through the micro grooves, and the heat transfer property and mass transfer property of the flat aluminum belt heat pipe are remarkably improved.

The invention provides a flat heat pipe based on a liquid absorbing core of a composite structure. The flat heat pipe comprises baseplates, the liquid absorbing core and a liquid filling pipe, whereinthe liquid absorbing core is arranged between the baseplates, and comprises supporting columns and foamed nickel components; the baseplates comprise an upper baseplate and a lower baseplate; the supporting columns are arranged on the upper baseplate and the lower baseplate; the foamed nickel components are matched with the inner wall surface structures of the baseplates; the liquid filling pipe is arranged between the upper baseplate and the lower baseplate; the interior of the flat heat pipe is filled with a working medium through the liquid filling pipe; and a channel where the working medium inside the flat heat pipe flows is jointly defined by the supporting columns and foamed nickel on the foamed nickel components. Through the adoption of the channel where the working medium inside the flat heat pipe flows and which is jointly defined by the supporting columns arranged in an array and the foamed nickel, the resistance to the backflow of the liquid working medium can be reduced when the capillary force is good, the flat heat pipe can achieve the better heat transfer property, and the reliability can be improved during the use of the flat heat pipe.