CN2335113Y

CN2335113Y - Spiral twisted elliptic section heat-exchanging pipe

Info

Publication number: CN2335113Y
Application number: CN 97221659
Authority: CN
Inventors: 孟继安
Original assignee: Individual
Current assignee: Meng Jian
Priority date: 1997-07-18
Filing date: 1997-07-18
Publication date: 1999-08-25
Anticipated expiration: 2007-07-18

Abstract

The utility model relates to a spiral twisted elliptic section heat-exchanging pipe, composed of a rolling-formed spiral twisted segment with an elliptic section and a straight segment whose both ends forms a circular section. The utility model has the advantages that the spiral twisted elliptic section heat-exchanging pipe causes the heat-exchanging medium of the inner and outer of the pipe to generate a forced rotational flow, the utility model has high heat exchange coefficient, and particularly can generate obvious enhanced heat transfer effect on the heat transferring of low heat transferring adhesive, easy fouling generated and not clear medium, and the utility model has the advantages of small flow resistance, non-perishable fouling, good safety, easy manufacture and low cost.

Description

Helically twisted elliptic-section heat exchange pipe

The utility model relates to a kind of augmentation of heat transfer heat exchanger tube, particularly a kind of on-circular cross-section heat exchanger tube.

At present, larger specific gravity is especially occupied in the process industrial field that shell-and-tube heat exchanger is widely used in refining oil, chemical industry, power etc. need heat exchange in oil refining and chemical system device, account for the 30%-40% of petrochemical industry process equipment gross weight.In order to reduce the weight of heat transmission equipment, reduce the volume of heat transmission equipment, should make every effort to strengthening heat transfer.Augmentation of heat transfer mostly is that the disturbance by convection cell realizes, the effect of its disturbance has determined the degree that heat exchange property improves.Having developed multiple enhanced heat transfer component in recent years also partly is applied, as insert in screwed pipe, spiral grooved tube, the pipe (distortion band, spring etc.), bellows, bellows tube etc., but all there is some deficiency in various degree in these augmentation of heat transfer approach simultaneously, as increase flow resistance, coking fouling even obstruction, security reduction and processing charges increase etc., in actual applying, be subjected to certain limitation.

The purpose of this utility model is that a kind of helically twisted elliptic-section augmentation of heat transfer heat exchanger tube that makes heat transferring medium produce rotational flow will be provided, and it has, and augmentation of heat transfer is effective, flow resistance is little, heat exchanging medium adaptability strong, be difficult for the coking fouling and be difficult for obstruction and the good characteristics of security.

The purpose of this utility model is achieved in that

(1) uses some rolls to adjustable center distance and two axial lines antarafacial intersection, the circular cross-section heat exchanger tube is rolled into ellipse shape (axial symmetry or approximate zhou duicheng tuxing with major diameter and minor axis, as ellipse, approximate ellipsoidal and Long Circle) cross section, elliptic-section forms helically twisted shape along the heat exchanger tube axial line.When flowing, heat transferring medium will produce stronger rotation disturbance in this heat exchanger tube with helical duct, thus augmentation of heat transfer.This structure is the thought that integrates helicla flute (the tube wall convection cell by roll forming produces flow-disturbing) and pipe interpolation distortion band (helical duct of formation produces fluid and forces eddy flow) convection cell disturbance, has than spiral grooved tube and the better effect of pipe interpolation distortion band convection cell disturbance.The rolling parent tube of helically twisted elliptic-section heat exchange pipe can be the sliding cross section of circular light pipe, screwed pipe and spiral grooved tube, therefore the helically twisted elliptic-section heat exchange pipe of roll forming also can be smooth cross section pipe, screwed pipe and spiral grooved tube, but also can make heat exchanger tube form concavo-convex tube wall face by roll forming, further improve the effect of augmentation of heat transfer.

Consider and the connected mode of tube sheet that (2) the pipe two ends still keep its circular cross-section.Another effect of this structure makes extratubal fluid be easy to become longitudinal stream from cross-current when being heat exchange, reduces fluid flow resistance.

The utility model compared with prior art has the following advantages.

(1) forces eddy flow owing in the pipe of helically twisted elliptic-section heat exchange pipe and outside the pipe heat transferring medium is produced, strengthened diabatic process, particularly the heat transfer for some resisting mediums that are difficult to conduct heat, the medium that is easy to coking (except that screwed pipe) fouling and unholiness medium has tangible augmentation of heat transfer effect, as petroleum refining industry etc., general heat transfer coefficient can improve more than 40%.Helically twisted elliptic-section screwed pipe is applicable to the heat transfer occasion of the outer entire thermal resistance of pipe for the control thermal resistance, or manages the more serious occasion of outer fouling, and it is higher or be easy to the occasion of coking not to be suitable for solid dust content.

(2) owing to force eddy flow fully to wash away tube wall, destroy the condition of finishing the close-burning dirt, thereby in actual moving process, can keep augmentation of heat transfer effect preferably all the time.The effect that the helically twisted tube wall of heat exchanger tube makes fluid produce eddy flow, it is unobstructed that heat transferring medium is flowed, and flow resistance is less.

(3) because helically twisted elliptic-section heat exchange pipe adopts circular smooth cross section pipe, screwed pipe and spiral grooved tube by rolling moulding, it is little to roll distortion, internal stress is little, have the low characteristics of moulding of being easy to and cost, the more important thing is and still kept former circular tube can bear the characteristics of HTHP and security reliably, the pressure-bearing etc. that is suitable for exchange heat pipe among the GB151 " steel tube shell type heat exchanger " requires and the technical conditions and the structural parameters requirement of corresponding design of heat exchanger manufacturing, thereby be widely used, also be easy to promote.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof.

Fig. 1 is the structural representation of helically twisted elliptic-section heat exchange pipe.

Fig. 2 is the distortion section vertical profile cross section example of helically twisted elliptic-section heat exchange pipe.Among the figure, (a) being the standard ellipse tee section, (b) is four tangent arc tee sections, (c) is the sub-elliptical tee section, (d) is long round section.Wherein (c) and (d) be the special shape of (b) is the sub-elliptical tee section when four tangent arcs and standard ellipse profile are close (match), be long round section when the r=B/2 in four tangent arcs.

See Fig. 1, Fig. 2, concrete structure of the present utility model is as follows:

Helically twisted elliptic-section heat exchange pipe is made up of helically twisted section of elliptic-section and two terminal circle tee section straight section.Helically twisted rotation direction can be dextrorotation, also can be for left-handed.

Helically twisted elliptic-section can be axial symmetry or the approximate axial symmetry cross section that ellipse, four tangent circle arcs, approximate ellipsoidal and Long Circle etc. have major diameter and minor axis, wherein selects elliptic-section headed by ellipse or sub-elliptical tee section.

Elliptic-section can be uiform section, also can be the variable cross-section of even variation, its screw pitch can for constant pitch apart from also can being irregular pitch, wherein with etc. pitch and uiform section be easy to moulding and simplify corresponding heat transmission equipment manufacturing process and first-selection.

The ratio of the length diameter of axle of elliptic-section is A/B=1.1-2, and wherein A/B=1.4-1.6 is a preferred value; Screw pitch S is S/ π d=2-30 with the ratio of heat exchanger tube outer perimeter π d, and wherein S/ π d=4-8 is a preferred value; Pipe two terminal circle tee section straight section length L 0=50-1000mm, wherein L0=200-400mm is a preferred value.

The rolling parent tube of helically twisted elliptic-section heat exchange pipe can be the sliding cross section of circular light pipe, screwed pipe and spiral grooved tube; The helically twisted elliptic-section heat exchange pipe of roll forming also can be the smooth cross section of helically twisted ellipse shape pipe, screwed pipe and spiral grooved tube, but also can make heat exchanger tube form concavo-convex tube wall face by roll forming, further improves the effect of augmentation of heat transfer.

Fig. 3 is the method for the rolling schematic diagram of helically twisted elliptic-section heat exchange pipe.The manufacture method of helically twisted elliptic-section heat exchange pipe is to use some rolls that adjustable center distance and two axial lines antarafacial are intersected with circular cross-section parent tube roll forming.The quantity of roll can be a pair of, how rightly also can be, wherein preferred 1 to 2 pair.The axis antarafacial angle β of every breaker roll=4 °-55 °, its preferred value is β=10 °-28 °.

Claims

1 helically twisted elliptic-section heat exchange pipe is made up of helically twisted section of elliptic-section of roll forming and pipe two terminal circle tee section straight section, and the ratio that it is characterized in that the length diameter of axle of elliptic-section is A/B=1.1-2, and wherein A/B=1.4-1.6 is a preferred value; Screw pitch S is S/ π d=2-30 with the ratio of heat exchanger tube outer perimeter π d, and wherein S/ π d=4-8 is a preferred value; Pipe two terminal circle tee section straight section length L 0=50-1000mm, wherein L0=200-400mm is a preferred value.

2 according to the described heat exchanger tube of claim 1, the helically twisted elliptic-section of feature base can be axial symmetry or the approximate axial symmetry cross section that ellipse, four tangent circle arcs, approximate ellipsoidal and Long Circle etc. have major diameter and minor axis, wherein selects elliptic-section headed by ellipse or sub-elliptical tee section.

3 is that elliptic-section can be uiform section according to the described heat exchanger tube of claim 1, feature, also can be the variable cross-section of even variation, its screw pitch can for constant pitch apart from also being irregular pitch, pitch and uiform section such as first-selection wherein.

4 according to the described heat exchanger tube of claim 1, and feature is that the rolling parent tube of helically twisted elliptic-section heat exchange pipe can be the sliding cross section of circular light pipe, screwed pipe and spiral grooved tube; The helically twisted elliptic-section heat exchange pipe of roll forming also can be the smooth cross section of helically twisted ellipse shape pipe, screwed pipe and spiral grooved tube, but also can make heat exchanger tube form concavo-convex tube wall face by roll forming.