CN2293790Y

CN2293790Y - Spherical concave-convex heat exchanger

Info

Publication number: CN2293790Y
Application number: CN 96235149
Authority: CN
Inventors: 刘吉普; 文美纯; 陈资滨
Original assignee: Xiangtan University
Current assignee: Xiangtan University
Priority date: 1996-06-27
Filing date: 1996-06-27
Publication date: 1998-10-07
Anticipated expiration: 2006-06-27

Abstract

The utility model relates to a spherical-surface-shaped concave-convex heat-exchanging pipe, a novel enhancing heat-transferring heat-exchanging pipe, which is formed by the fact that the pipe wall of an original smooth heat-exchanging pipe is ground into spherical-surface-shaped concave-convex parts. The utility model not only can effectively improve heat-transferring coefficients inside and outside the heat-exchanging pipe, but also can decelerate induction vibration generated by fluid flow inside the heat exchanger, which extends the service life, the maintenance period and the cleaning period of the heat exchanger because the resistance of the fluid flow is small, production is simple, and power consumption is saved. The utility model can be widely used for manufacturing shell and pipe highly effective energy-saving heat exchangers.

Description

Convex concave spherical heat exchange tubes

The utility model relates to the manufacturing of general heat exchanger manufacturing technology, particularly heat exchanger tube.

As everyone knows, influencing the topmost factor of monophasic fluid convection heat transfer intensity is laminar sublayer, and the methods such as turbulence intensity that often adopt the thickness of attenuated layer laminar sublayer to increase fluid are simultaneously strengthened the convection heat transfer' heat-transfer by convection of monophasic fluid.Thereby, in traditional tube bundle heat exchanger, carry out augmentation of heat transfer by taking to change the heat exchanger tube cross sectional shape, improve in the boundary layer heat exchange operating mode and increasing means such as tube wall roughness.For example, traditional smooth heat exchanger tube is processed into outer ribbed pipe, screwed pipe, band pipe, intersects screwed pipe etc., but they have make makings, install inconvenient; By the effect of in forming baffle plate type, deflection bar type, arch area or the central area shell-and-tube heat exchanger that cloth tubular type etc. is not traditional, failing to have given play to well its augmentation of heat transfer.

The purpose of this utility model provides a kind of novel reinforced heat transfer heat exchanger tube, it not only can improve the inside and outside convective heat-transfer coefficient of heat exchange tube effectively, and fluid flow resistance is low, make simple, energy efficient, can also slow down the heat exchanger inner fluid flows the induced vibration that produces, service life and the maintenance and the cleaning frequency of slowing down scaling rate, prolongation heat exchanger, especially in traditional shell-and-tube heat exchanger such as assembling baffle plate type, deflection bar type, arch area or central not cloth tubular type, can give play to the effect of its enhanced heat exchange, produce the pipe shell type highly effective energy-saving heat exchanger.

The difference of the utility model augmentation of heat transfer heat exchanger tube and existing heat exchanger tube is: the pit (accompanying drawing) that rolls out sphere shape in smooth heat exchanger tube outside wall surface, the ratio of pipe outer wall sphere shape pit dark e and heat exchanger tube diameter d equals 0.01～0.10, the pit distance s equals 0.05～1.50 with the ratio of heat exchanger tube diameter d, by being arranged in isosceles triangle, scalene triangle, equilateral triangle, square or spirality along row or fork row.After rolling processing, because the plastic deformation of tubing, the convex concave spherical face becomes arc transition with the tube wall face, forms former smooth heat exchanger tube outside wall surface and is covered with sphere shape pit, and inside pipe wall then is the rough surface corresponding to a kind of like this special construction of sphere shape convex surface of outer wall sphere shape pit.

Use convex concave spherical heat exchange tubes and be assembled into shell-and-tube heat exchanger, when extratubal fluid laterally or during the parallel baffled convex concave spherical heat exchange tubes, the sphere shape pit of pipe outer wall makes fluid inhomogeneous along the VELOCITY DISTRIBUTION of all angles on the same circumference of pipe, the direction that fluid flows changes along sphere shape pit, make the fluid produce boundary layer separation, whirlpool and secondary stream effect and Three-dimensional Flow, strengthened the momentum change between the little fluid of big fluid of turbulence intensity and turbulence intensity.Fluid in the pipe produces along the shunting of sphere shape convex surface with along the streaming of sphere shape convex surface under the effect of inside pipe wall face sphere shape convex surface, has destroyed the boundary layer that fluid flows.Thereby the application convex concave spherical heat exchange tubes is carried out the monophasic fluid convection heat transfer' heat-transfer by convection following advantage:

1. convex concave spherical heat exchange tubes pipe outer wall is a sphere shape pit, and inside pipe wall is corresponding sphere shape convex surface, can make the inside and outside low Reynolds (Reynold's) criterion Re fluid of pipe produce Turbulence Flow simultaneously, has strengthened the convection heat transfer' heat-transfer by convection of outer fluid in the pipe, has reduced the speed of fouling.

2. convex concave spherical heat exchange tubes does not resemble the circumferential size that increases pipe the outer ribbed pipe, can be conveniently used in the shell-and-tube heat exchanger of traditional structure, thereby it is compact that heat-exchanging tube bundle is arranged, forms compact heat exchanger.

3. convex concave spherical heat exchange tubes generally can make shell-and-tube heat exchanger tube side and shell side heat transfer comprehensive economic index, the individual heat transfer coefficient α of tube side (or shell side) _iWith tube side (or shell side) resistance depreciation Δ p _iThe smooth heat exchanger tube of comparing improve 20%～80%.

4. the convex concave spherical heat exchange tubes processing and fabricating is simple, and cost is low, and processes convex concave spherical owing to rolling on original smooth heat exchanger tube tube wall, has increased the rigidity of pipe, has reduced the induced vibration that fluid flows and produces, and has prolonged the service life of heat exchanger tube.

Accompanying drawing is the convex concave spherical heat exchange tubes schematic diagram.

The utility model is achieved in that on the smooth heat exchanger tube that materials such as aluminium, copper, steel, titanium, stainless steel are made, and reserves the smooth pipeline section that is slightly larger than the heat exchanger tube plate thickness, connects with heat exchanger tube sheet being used for.Then on lathe, utilization has the roll forming head of Φ 5～30mm sphere boss, roll out at smooth heat exchanger tube outer wall: the ratio of pipe outer wall sphere shape pit dark e and heat exchanger tube diameter d equals 0.01～0.10, the pit distance s equals 0.05～1.50 with the ratio of heat exchanger tube diameter d, become the sphere shape pit of isosceles triangle, scalene triangle, equilateral triangle, square or helical pattern, inside pipe wall then forms the rough surface of the sphere shape convex surface so a kind of special construction corresponding with managing outside wall surface sphere shape pit.

Illustrate below in conjunction with example shown in the drawings:

Get Φ a 25 * 2mm, long 6000mm, material is the smooth heat exchanger tube of No. 20 Fine Steel Casting irons, reserves the long smooth heat exchange pipeline section of 50mm at two.On lathe, with the roll forming head of the special spherical plush copper that has Φ 15mm, lateral feed and vertical mill speed by regulating the roll forming head in the interval of smooth heat exchanger tube pipe range 5900mm, roll out the sphere shape pit of dark 1 mm.Arrange 4 sphere shape pits on each cross section of pipe, the sphere shape pit on two cross sections of the 10mm of whenever being separated by interlaces 45 °.Form the sphere shape pit that isosceles triangle is arranged at the pipe outer wall, pipe internal surface is then because the plastic deformation of tubing is rolled out the sphere shape convex surface corresponding with managing outer wall sphere shape pit.The utility model-convex concave spherical heat exchange tubes has just been made in processing continuously in pipe range 5900mm effective coverage.

Inside and outside convective heat-transfer coefficient, the fluid flow resistance of thermoexcell pipe is low effectively for convex concave spherical heat exchange tubes, be applied in baffle plate type, deflection bar type, arch area or the central area shell-and-tube heat exchanger that cloth tubular type etc. is not traditional, the similar heat exchangers of the smooth heat exchanger tube of comparable application is saved heat transfer area more than 25%, thereby can produce the pipe shell type highly effective energy-saving heat exchanger.

Claims

1. convex concave spherical heat exchange tubes relates to general heat exchanger manufacturing technology, be particularly related to the manufacturing field of heat exchanger tube, it is that the tube wall that utilizes that the metal pipe material by different materials constitutes carries out heat conducting tubulose heat-exchange device, it is characterized in that: the sphere shape pit of heat exchanger tube outside wall surface for arranging in certain sequence, internal face is the sphere shape convex surface corresponding with outer wall sphere shape pit.

2. convex concave spherical heat exchange tubes according to claim 1, the ratio of pipe outer wall sphere shape pit dark e and heat exchanger tube diameter d equals 0.01～0.10, the pit distance s equals 0.05～1.50 with the ratio of heat exchanger tube diameter d, and sphere shape pit is isosceles triangle, scalene triangle, equilateral triangle, square or helical pattern at the tube wall face.