The inner chiasma spiral exterior three-dimensional diamond-type rib double-side intensify heat transfer pipe
The utility model relates to a kind of intensify heat transfer pipe, particularly a kind of inner chiasma spiral exterior three-dimensional diamond-type rib double-side intensify heat transfer pipe.
Shell-and-tube heat exchanger is present most widely used heat transmission equipment, is prevalent in industrial circles such as energy source and power, petrochemical industry, metallurgical material.It also is rationally to utilize and the key equipment of saving the existing energy, tapping a new source of energy, and accounts for 70% of whole heat exchangers.In order to reduce the weight of shell-and-tube heat exchanger, reduce the volume of heat transmission equipment, energy-saving and cost-reducing, should make every effort to strengthen its diabatic process.Wherein, with the primary element of shell-and-tube heat exchanger---heat-transfer pipe, changing intensify heat transfer pipe into by plain tube is to realize its main path efficient, compact heat exchange.
At present, comparatively Chang Yong intensify heat transfer pipe has insertion fortification substance in spiral grooved tube, spiral band (screwed pipe), distorted elliptical pipe, helical groove pipe, cross grooved pipe, bellows, interior finned tube and the pipe, but they have separately the characteristics and the scope of application.Spiral grooved tube is by roll extrusion machining, be shaped to helical groove at tube outer surface, and the pipe internal surface corresponding shaping is a spiral salient, so that tube fluid obtains partial rotation, help the attenuate boundary layer, and destroy turbulent boundary layer by periodic disturbance, be mainly used in the heat exchange of monophasic fluid, the heat-transfer mechanism of spiral band (screwed pipe) and helical groove pipe and spiral grooved tube and property class are seemingly, all the heat exchange of low Re (Reynolds number) being strengthened has than obvious effects, but strengthens little to the heat exchange of high Re.Bellows is the continuous wave pattern curve inside and outside by particular manufacturing craft thin-walled carbon pipe or stainless steel tube being processed into, and its longitudinal section waveform is formed by big or small circular arc is tangent.This heat-transfer pipe has certain for descaling function, and anti-scale inhibition ability is better.But heat transfer property is under identical Re, not as spiral grooved tube.Also have following some shortcomings in addition: flow resistance is big in the pipe that (1) produces, pressure drop is big; (2) bearing capacity has only about 1/10 of plain tube, can not be applied to the mesohigh occasion; (3) under low Re, or high-viscosity fluid heat exchange occasion, the effect of augmentation of heat transfer is not too obvious.When (4) being used for falling film evaporation, the splashing of liquid film, lift-off phenomenon easily occur when flow is big, heat transfer property descends.The distorted elliptical pipe is by flattening and reversing two processes and make, the arbitrary section of pipe is Long Circle, be a kind of helically twisted elliptic cross-section pipe, its enhanced heat transfer mechanism is by pipe inside spin distorted ellipsoidal passage, makes fluid produce rotation and secondary vortices flow disturbance.The weak point of this kind heat-transfer pipe: the one, not obvious to the heat exchange strengthening effect of low Re, only under high Re, to compare with smooth pipe, the convection transfer rate in the distorted elliptical pipe pipe can improve 35%-55%; The 2nd, when heat exchange strengthened, the pipe internal resistance also increased, and increment is quite big.Insert fortification substance in interior finned tube and the pipe, be mainly used in pipe interior single-phase convection heat exchange and phase-change heat-exchange as the double-helix spring pipe, the mechanism that the single-phase convection heat exchange is strengthened in the interior finned tube pipe is: the increase of the turbulent flow reinforced and heat transfer sheet area of wing, the contribution of both heat exchanging is roughly suitable, and the wing surface was easy to fouling in weak point was to manage.The double-helix spring pipe is to utilize the hairspring silk to be processed into double-helix spring, adopt soldering processes that double-helix spring and tube wall are welded together, thereby realize the reinforcement of heat exchange, its laminar heat transfer strengthening effect is remarkable, but the increase of pipe internal resistance is also more obvious, is suitable for the heat transfer of clean medium.
In many shell-and-tube heat exchangers, as widely used high-pressure feed-water heater and low-pressure feed heater etc. in electrical production, the interior feedwater of their pipe convection transfer rate is suitable with the outer vapour condensation heat transfer coefficient of pipe, thereby strengthens the just necessary bilateral intensify heat transfer pipe that adopts of heat transfer of such heat exchanger.But in rolling stock, heavy-duty machinery, generator in the heat exchanger such as widely used oil cooler, the convection transfer rate of water side is much larger than shell side oil side convection transfer rate in the pipe, heat transfer resistance is in the oily side of shell side (outside the pipe), therefore, the heat-transfer pipe that is used for oil cooler should adopt the bilateral intensify heat transfer pipe, and the heat transfer outside a tube coefficient should be higher than the intraductal heat exchange coefficient.But above-mentioned several intensify heat transfer pipes or can only strengthen one-sided heat exchange, or the both sides of enhanced heat exchange exist the coefficient of heat transfer undesirable.
Theoretical research shows, for high viscosity, low flow velocity heat exchanger, augmentation of heat transfer should adopt the high fin heat transfer pipe that is interrupted each other, the fin that the outer nothing of the pipe of spiral grooved tube, spiral band (screwed pipe), distorted elliptical pipe, helical groove pipe, cross grooved pipe, bellows is interrupted each other.The utility model patent applicant once proposed the outer two-sided strengthened heat-transfer pipe (Chinese patent of ratchet type of a kind of inside spin, ZL03274468.4), its cardinal principle is to utilize the mechanism of the three-dimensional extended surface peening heat transfer of pipe outer wall, become wing by being machined into tube outer surface, roll extrusion, form curved surface ratchet fin at tube-surface, to improve the heat transfer outside a tube coefficient.Owing to structural reason, the ratchet fin height of this heat-transfer pipe is less, and the pipe inter-spiral groove is unidirectional.For high viscosity, as the single-phase convection heat exchange of oil product, its augmentation of heat transfer efficient still has certain limit, and the fouling in managing is still failed to solve well.Up to the present, also do not occur a kind ofly can reaching the inside and outside heat transfer requirement of enhanced tube, can prevent fouling again, and simple in structure, save the thermoexcell of material, thereby make shell-and-tube heat exchanger be subjected to certain restriction in the use.
The utility model content
The purpose of this utility model be to overcome in the prior art exist can not take into account that the inside and outside heat-transfer effect of pipe, heat transfer coefficient are low, anti-tartar and anti-scaling function difference and the big defective of sheet metal consumption, a kind of inner chiasma spiral exterior three-dimensional diamond-type rib double-side intensify heat transfer pipe is provided.
The utility model can be achieved by the following technical programs: a kind of inner chiasma spiral exterior three-dimensional diamond-type rib double-side intensify heat transfer pipe, comprise heat-transfer pipe matrix, the outer diamond-type rib of pipe and pipe inter-spiral groove, described heat-transfer pipe matrix, the outer diamond-type rib of pipe and pipe inter-spiral groove are integrated, managing outer diamond-type rib is interrupted each other, and curl distribution vertically constitutes the three-dimensional extended surface of whole outer surface of tube wall, pipe inter-spiral groove cross-distribution is in the heat-transfer pipe matrix, and appearance in pairs with being left and right sides rotation direction.
The outer diamond-type rib of pipe described in the utility model is intersected to form mutually by left-handed bull evagination rectangular thread and dextrorotation indent single head or bull rectangular thread, or it is intersect to form mutually, and vertical with tubular axis line or pipe outside wall surface by dextrorotation bull evagination rectangular thread and left-handed indent single head or bull rectangular thread.The pitch of evagination rectangular thread is greater than the pitch of indent rectangular thread, and the pitch of evagination rectangular thread is 100～200mm, and the pitch of indent rectangular thread is 20～50mm.Evagination rectangular thread helixangle is 60 °～80 °, and indent rectangular thread pitch angle alpha will is 110 °～150 °.Rectangular thread axial cross section width equates or is unequal that formed diamond-type rib overall volume correspondingly equates or be unequal.The axial spacing of diamond-type rib is 0.5～3.5mm, and the rhombus fin is thick to be 0.7～2.5mm, and rhombus fin height is 1.2mm～4.5mm.
Pipe inter-spiral groove described in the utility model is intersected to form mutually by left-handed indent single head or multi-head spiral groove and dextrorotation indent single head or multi-head spiral groove, and the pitch of left and right spiral grooves is 2～6mm, ditch groove depth 0.20mm～2.5mm.The cross sectional shape of pipe inter-spiral groove is trapezoidal, circular arc, triangle, rectangle or polygon, and the left-hand screw angle θ 1 of pipe inter-spiral groove equates with right-hand screw angle θ 2 or unequal that left-hand screw angle θ 1 and right-hand screw angle θ 2 are 75 °～85 °.
The material of heat-transfer pipe matrix described in the utility model, the outer diamond-type rib of pipe and pipe inter-spiral groove is copper, copper alloy, aluminium, aluminium-alloy pipe, carbon steel or other metal materials.
Compared with prior art, the utlity model has following advantage:
1, the outer diamond-type rib of pipe described in the utility model, pipe inter-spiral groove are integrated with the pipe matrix, contactless thermal resistance, the outer diamond-type rib that is interrupted mutually that utilizes of pipe is strengthened heat convection or condensing heat-exchange, utilize the cross-helicity groove to strengthen heat convection in the pipe, can fully take into account in the pipe like this and the outer requirement of pipe enhanced heat exchange;
2, the utility model utilization pipe exterior three-dimensional diamond-type rib destroys the viscous flow boundary layer when increasing heat transfer area, has improved convection transfer rate and condensing heat-exchange coefficient;
3, become the spiral grooves of intersection promulgation can bring out secondary separation stream in the pipe of the present utility model, thereby promote the turbulent extent aggravation, convective heat-transfer coefficient in the raising pipe increases anti-scale inhibition ability, keeps lasting good heat exchange property;
4, the plain tube that the utility model is identical with the caliber parameter is compared, under condensing condition, the single tube overall heat-transfer coefficient can improve more than 120%, and under unit are heat convection operating mode, overall heat-transfer coefficient can improve more than 80%, and that tube drop increases is not obvious, under same heat transfer boundary condition, compact conformation is saved metal material, be a kind of high-effect bilateral intensify heat transfer pipe, can be widely used in managing the less occasion of outside film coefficient of heat transfer.
Description of drawings
Fig. 1 is a tomograph of the present utility model;
Fig. 2 is a partial 3 d structure chart of the present utility model;
Fig. 3 is an axial view of the present utility model;
Fig. 4 is a front view of the present utility model;
Fig. 5 is an axial section schematic diagram of the present utility model.
Description of symbols in the accompanying drawing:
The 1-diamond-type rib; 2-heat-transfer pipe matrix; The 3-spiral grooves;
The rhombus fin height in the t-tube wall outside; β-evagination rectangular thread helical angle;
α-indent rectangular thread helical angle;
The axial width of diamond-type rib sheet in the δ 1-tube wall outside; The axial spacing of diamond-type rib sheet in the δ 2-tube wall outside;
The left-hand screw angle of θ 1-spiral grooves; The right-hand screw angle of θ 2-spiral grooves;
The helical pitch (or pitch) of F1-left-hand screw groove; The helical pitch (or pitch) of F2-right-hand screw groove;
The ditch groove depth of b-spiral grooves
The specific embodiment
Come the specific embodiment of the present utility model is described in detail below in conjunction with accompanying drawing.
As shown in Figure 1, the lateral surface of tube wall is a diamond-type rib described in the utility model, medial surface is the cross-helicity groove, Fig. 2 has provided the partial 3 d structure chart of utility model, Fig. 3 has provided axial view of the present utility model, Fig. 4 has provided front view of the present utility model, and Fig. 5 has provided axial section schematic diagram of the present utility model.The utility model combines helical groove pipe, spiral grooved tube, bellows, interior finned tube and the serrated fin heat-transfer pipe advantage at enforcing condensation heat transfer and convection heat transfer' heat-transfer by convection, and has avoided their deficiency.
To shown in Figure 5, the utility model is provided with 16～45 equally distributed, highly identical evagination rectangular threads at the heat-transfer pipe outer surface as Fig. 1, also is provided with 1～5 opposite with above-mentioned rotation direction, equally distributed indent spiral grooves at the heat-transfer pipe outer surface simultaneously.The indent spiral grooves cuts into the diamond-type rib that many curls distribute with the evagination rectangular thread, and these diamond-type ribs constitute special three-dimensional extended surface.Each diamond-type rib and heat-transfer pipe outer tube wall are integrated, and disconnect mutually in trench bottom with on every side 4 diamond-type ribs, and the side of each diamond-type rib is vertical with tube wall or tubular axis line.The height of the outer diamond-type rib of pipe is high more, and specific area is big more, and it is also good more that its heat transfer outside a tube is strengthened, but has also increased the resistance of extratubal fluid simultaneously.Therefore, the high t of each rhombus fin can be taken as 1.2mm～4.5mm, axial spacing δ 2=0.5～3.5mm, and, the thick δ 1=0.7～2.5mm of fin.
Be provided with right that occur in pairs, the single head of a first from left or bull right hand helix groove and left-handed spiral grooves at the medial surface of heat-transfer pipe, right hand helix groove and left-handed spiral grooves are intersected mutually, constitute the inboard spiral grooves of the utility model heat-transfer pipe.The degree of depth of pipe inter-spiral groove is dark more, and helical pitch (or pitch) is more little, and it is also big more to strengthen convective heat-transfer coefficient in its pipe, but has also increased the pressure drop of tube fluid simultaneously.Therefore, the helixangle 1 of every spiral grooves or θ 1 can be taken as 75 °～85 °, helical pitch (or pitch) F1 or F2=2～6mm, ditch groove depth b=0.20mm～2.5mm.
This unique texture that the utility model is above-mentioned has very strong vortex core, helps the mobile state of disturbance gas-liquid two-phase, reduces the thickness and the thermal resistance of viscous flow bottom, thereby has high heat-transfer effect.Moreover the pipe integrated production technology of application seamless has guaranteed the integrality of outer surface, inner surface and pipe basal body structure, has eliminated the defective of quality problems such as the thermal resistance increase that causes because of weld seam and shape dislocation etc.The utility model is applicable to heat convection, the multi-component vapor condensation of strengthening the high viscosity fluid and contains the water vapour condensation of incoagulable gas, the heat convection of no phase change fluid etc., characteristics with coefficient of heat transfer height, and anti-tartar and antiscale bigger than heating surface, can be widely used in the heat exchange of various high viscosity oil products in power source, the field of petrochemical industry, heat exchangers such as the condensation of water vapour are to replace light pipe or low fin screwed pipe, spiral grooved tube etc.
Principle of the present utility model and act on as follows:
The mechanism of the outer convection heat transfer' heat-transfer by convection of the utility model enhanced tube is: the diamond-type rib that the outer curl vertically of pipe distributes is three-dimensional discontinuity fin, when being used for the single-phase convection heat exchange, this discontinuity fin can periodically cut off the retention layer of fluid on the fin, direction of flow is constantly changed and and the boundary layer peel off, reduced the thickness of detention layer consumingly.Simultaneously, when fluid flows through gap between the diamond-type rib, can produce strong disturbance, the secondary stream (spiral flow and boundary layer separation flow) that brings out further attenuate the thickness of fluid retention layer, this to reduce thermal resistance, to improve the coefficient of heat transfer highly beneficial.The high Prandtl (Prandtl) that concentrates on viscous sublayer for heat transmission resistance counts flow of oil, and the three-dimensional discontinuity fin augmentation of heat transfer usefulness of this structure is better.
On the other hand, when fluid flows, make shearing motion in helical flow path, because the motional inertia of fluid makes flow boundary layer constantly separate with heat transfer boundary layer with diamond-type rib.After the separation, fluid will produce vortex, and the impact of fluid to the diamond-type rib wall takes place, and the friendship that can make wall boundary layer fluid micelle and main flow area fluid micellar strengthen quality and momentum passes and substitutes, and convection heat transfer' heat-transfer by convection is strengthened.
When the utility model is used for the two-phase condensing heat-exchange, diamond-type rib with special three-dimensional extended surface texture can be given full play to the condensate liquid surface tension effects, make the continuous phase of near wall cause overheated or supercooled state promotion phase transformation, and the drop that the condensation of diamond-type rib top is got off drawn in recess, make the very fast renewal of film at diamond-type rib place of evagination, help to facilitate the continuous generation of condensate liquid, and rapidly from the gap root of diamond-type rib overhead stream between both sides of the chest, and under the effect of spiral power, get rid of from gilled tube fast, can strengthen the disturbance in the liquid film like this, its effect is to have improved pipe outside condensation side heat transfer coefficient, reduced the condensate liquid thermal resistance, made diabatic process obtain reinforcement.
The mechanism of convection heat transfer' heat-transfer by convection is in the utility model enhanced tube: the spiral grooves of inside pipe wall makes a part of fluid near wall produce additional helical flow, can improve flow rate of fluid like this, and fluid is rotated, and thermal resistance is reduced, and heat transfer is enhanced; Meanwhile, near the wall another part fluid is subjected to the effect of the helical form fin that the cross-helicity groove produced, produce reverse barometric gradient at the fin rear side, and cause secondary separation and flow, promoted fluid radially to mix, main flow fluid and boundary layer fluid mixability are increased, thereby accelerate by the heat transmission of wall to bodies of fluid.
Because the utility model is provided with the spiral grooves of intersection at inside pipe wall, the spiral grooves of this intersection can make tube fluid under low Re, the secondary separation stream that produces helical flow and cause, make fluid present turbulence state, tube wall had flushing action preferably, the dielectric deposition chance reduces, fully prolonged the induction period of fouling, the spiral grooves of Jiao Chaing changes in axial local curvature simultaneously, also can force the dirt layer that has formed to split again comes off, add the effect of separated flow, realize the automatic desludging effect.
Enforcement available light slip pipe of the present utility model is a blank, adopts the pipe mill of special use also to carry out with the mode of extruding and few/no machining, and pipe is interior to be processed with the outer substep of pipe.Its processing method is as follows:
Copper, aluminium or steel plain tube are placed on the special-purpose pipe mill, be inserted into in the special mould of equilateral triangle arrangement, clamping mold, slowly pull out steel pipe vertically, increase along with amount of compression, metal radially and axial flow makes metal plastic deformation form bull evagination rectangular thread by radial and axial extruding.Then, replace with another set of dedicated tool, the reverse rotation pipe fitting, dedicated tool makes metal produce plastic deformation and forms recessed spiral grooves, it is cut into left and right sides two parts to the metal evagination rectangular thread that back shapes, two-part thickness is respectively axial width δ 1 of diamond-type rib sheet and the axial spacing δ 2 of diamond-type rib sheet, above-mentioned two steps add man-hour mould and the amount of feeding of cutter constitute rhombus fin height t.By this two step processing, but the just diamond-type rib 1 that distributes of the curl in the forming tube outside.At last, to carry out few cutting and extrusion process in the special slot rolling cutter insertion pipe, the slot rolling cutter can form left-handed spiral grooves by the material of extruded tube madial wall, reverse rotation pipe fitting again, material by the further extruded tube madial wall of slot rolling cutter can form the right hand helix groove, the mutual intersection of left-handed spiral grooves and right hand helix groove, cross-helicity flute surfaces that can the forming tube inwall.Through above several procedures, just can be with steel plain tube blank processing cost utility model.Table 1 is an object lesson of the present utility model:
Now transform example as effect of the present utility model be described with the thermal power plant oil cooler:
The heat transfer efficiency of certain power plant's bronzing slip pipe oil cooler is low, causes and oily temperature can't be cooled to set-point, makes relevant equipment break down, and influences the normal operation in power station.Now make the utility model with steel pipe, structural parameters such as above-mentioned object lesson of the present utility model to substitute original copper pipe in the oil cooler, do not have the copper transformation.
After the transformation,, adopt oil cooler of the present utility model higher by 28%～54% than the overall heat-transfer coefficient of bronzing slip pipe oil cooler with under the operating mode.This shows: although the steel pipe thermal conductivity factor less than half of copper pipe, total heat conductive efficiency of the present utility model will be higher than the bronzing slip pipe.This is because the utility model heat-transfer pipe outer surface three-dimensional diamond-type rib is discontinuous and distributes along the tube wall curl, can reduce the thickness and the thermal resistance of flow of oil viscous flow bottom, and specific area is 3 times of the bronzing slip pipe, for high viscosity oil, it is better that the roughness element augmentation of heat transfer efficiency ratio of this form hangs down fin screwed pipe, spiral grooved tube etc.