CN2646649Y

CN2646649Y - Inside spin and outside ratchet type double-face reinforced heat transferring tube

Info

Publication number: CN2646649Y
Application number: CN 03274468
Authority: CN
Inventors: 龙新峰; 欧伟成
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-09-12
Filing date: 2003-09-12
Publication date: 2004-10-06
Anticipated expiration: 2013-09-12

Abstract

The utility model provides an inner screw outer ratchet type double face reinforced heat conducting pipe. The outer surface of the pipe wall of the heat conducting pipe is provided with a plurality of curved surface ratchet shaped fins which are continuously arranged along the axial direction with spiral shapes and are integrated with the pipe wall; the curved surfaces of the curved surface ratchet shaped fins are connected with one another; the first screw angle A is 0.5 degree to 5 degree; the second screw angle B is 15 degree to 23 degree; the height of the curved surface ratchet shaped fins is 0.2mm to 2.5mm; the inner wall of the heat conducting pipe is provided with a spiral groove; the number of the head of the spiral groove is 1 to 25; the lead(or thread pitch) t is 1 to 450mm; the depth h is 0.15mm to 1.5mm. The utility model is characterized in high efficiency, energy saving, big heat conducting area and little scale formation on the pipe wall. The utility model can be widely applicable for the high and low pressure heat returning and heating, condenser, water cooling condenser, air cooler and oil cooler in the electric power, refrigerating and energy source fields.

Description

The outer two-sided strengthened heat-transfer pipe of ratchet type of inside spin

Technical field

The utility model relates to a kind of two-sided strengthened heat-transfer pipe, the outer two-sided strengthened heat-transfer pipe of ratchet type of particularly a kind of inside spin.

Background technology

Existing many heat exchangers, the heating of high-low pressure backheat, condenser, water-cooled condenser, air cooler and the oil cooler etc. used as the power plant, needs for aspects such as the sealing of heat exchanging device, pressure-bearings, the heat-transfer pipe that adopts mostly is the plain tube of no augmentation of heat transfer usefulness, or the cast of single face strengthening effect is only arranged, to making total exchange coefficient of the heat exchanger not high.

In recent years, increasingly serious along with the non-renewable energy resources shortage impels the research of augmentation of heat transfer and uses accelerated development, and the industrial circle that it is related and the form of heat exchanger are all very extensive.Wherein, the reinforcement of shell-and-tube heat exchanger is very attracting field, and this is because its application quantity is big, adaptation is wide, all might be applied in various industrial process.For improving the heat transfer efficiency of shell-and-tube heat exchanger, comparatively general way is that tube wall is processed into different shape, with the attenuate boundary layer, reduces thermal resistance, reaches the effect that improves condensation heat transfer and convection heat transfer' heat-transfer by convection.At present, improve in the heat-transfer effect of tube wall, more employing low thread pipe, spiral grooved tube, revolve casts such as ribbed pipe and serrated fin, above-mentioned several tubular heat-transfer pipe has certain effect to improving outer convective heat-transfer coefficient of pipe or condensing heat-exchange, when especially the serrated fin heat-transfer pipe is used for single working substance steam condensation, really can obtain good augmentation of heat transfer effect, but there are pipe circumferential eddy flow of stream or part barrier face eddy current, these secondary flow field thermogrades are little, fail fully to produce the part kinetic energy that the convection heat transfer' heat-transfer by convection effect has but consumed fluid, when being used for the condensation of many components working substance steam, the condensation heat transfer coefficient is low; And except that spiral grooved tube, when adopting steel tube, only can accomplish pipe outside single face augmentation of heat transfer.

Summary of the invention

The purpose of this utility model is to provide a kind of wide accommodation, the outer two-sided strengthened heat-transfer pipe of ratchet type of a kind of inside spin that heat transfer efficiency is high

For achieving the above object, the utility model has been taked following technical measures: the outer two-sided strengthened heat-transfer pipe of ratchet type of a kind of inside spin, wherein the outer surface of tube wall of heat-transfer pipe be provided with many vertically in the shape of a spiral the shape continuous distributed and with the incorporate curved surface ratchet-shaped of tube wall fin, adjoin each other between curved surface around each curved surface ratchet-shaped fin, its first helical angle A is 0.5 °～5 °, the second helical angle B is 15 °～23 °, and the high H of curved surface ratchet-shaped fin is 0.2mm～2.5mm; The heat-transfer pipe inwall is provided with spiral groove, and this spiral groove head number is 1～25, and helical pitch (or pitch) t is 1～450mm, and degree of depth h is 0.15mm～1.5mm.

On the basis of adopting above-mentioned measure, further improvement project is: the shape of cross section of the spiral groove of heat-transfer pipe inwall is good with trapezoidal or triangle.

Two-sided strengthened heat-transfer pipe of the present utility model has following beneficial effect:

1) the curved surface ratchet-shaped fin continuous distributed of outer surface of tube wall, and be connected complete contactless thermal resistance with the heat-transfer pipe outer tube wall is integrated.

2) can be in power plant's heat exchanger the instead of copper plain tube, can not only guarantee original thermic load, its heat transfer intensity also improves to some extent, can realize that fully the feed water system of boiler of power plant do not have the specification requirement of copper operation.

3) total coefficient of heat transfer of heat-transfer pipe improves 70%～96% than plain tube, improves 16%～37% than spiral grooved tube; And tube drop only increases about 20% than plain tube, is lower than the tube drop of spiral grooved tube.Anti-burst pressure＞the 8.9Mpa of Φ 25 * 3 steel heat-transfer pipes of the present utility model reaches safety standard; Therefore, can use on the heating of high-low pressure backheat, condenser, water-cooled condenser, air cooler and oil cooler, heat-transfer effect obviously is better than prior art, is specially adapted to the bigger power station bleeder heater of steam pressure excursion and strengthens; High-low pressure heater after the reinforcement can obtain higher feed temperature, realizes energy saving thereby reduce coal consumption.

4) the utility model is used for the high-low pressure heat exchanger, the comparable corresponding material plain tube of its overall heat-transfer coefficient improves 75%, save the heat exchange area more than 49% when the load operation, the heat-transfer surface trifoliate orange has reduced, tubing and tube sheet, cylinder material, whole processing are assembled and all can be reduced man-hour, thereby reduce manufacturing cost.To the such user in power plant, do the old scrap build of homalographic, can improve 13～16 ℃ of feed temperatures, standard coal consumption decline 7～9g/Kwh, heat consumption rate reduces 0.31%～0.49% approximately, the economic effect highly significant.

5) the utility model is used for high-pressure heater, its overall heat-transfer coefficient improves 73% than plain tube, can save 46% heat exchange area concerning device fabrication producer, the minimizing of heat exchange area, the material of tube sheet, cylindrical shell, whole processing are assembled and all can be reduced man-hour, thereby reduce manufacturing cost.To the such user in power plant, do the old scrap build of homalographic, heat consumption rate Qr can drop to 5163kJ/Kwh by original 6057kJ/Kwh; By annual operation 8200 hours, the caloric value of standard coal was 29308kJ/kg, 340 yuan of/ton calculating of coal price, and the high-pressure heater of a 125MW generating set can be saved 4232 tons of standard coals every year, closes 1,450,000 yuan of RMB.

Description of drawings

Fig. 1 is a front view of the present utility model;

Fig. 2 is a cutaway view of the present utility model;

Fig. 3 is a perspective view of the present utility model;

Fig. 4 is a sectional perspective structural representation of the present utility model.

The specific embodiment

Below in conjunction with accompanying drawing the utility model is done to describe further, but do not constitute any restriction of the present utility model.

As shown in Figure 1 and Figure 2, the outer two-sided strengthened heat-transfer pipe of ratchet type of inside spin of the present utility model, the external diameter of heat-transfer pipe is 25mm, internal diameter 19mm, the heat-transfer pipe outer surface of tube wall be provided with many vertically in the shape of a spiral the shape continuous distributed and with the incorporate curved surface ratchet-shaped of tube wall fin 1, adjoin each other between curved surface around each curved surface ratchet-shaped fin 1, its first helical angle A is 1.5 °, several 1; The second helical angle B is 20 °, several 33; The high H of curved surface ratchet-shaped fin is 1mm.The heat-transfer pipe inwall is provided with

spiral groove

2, and 2 numbers of this spiral groove are 1, and helical pitch (or pitch) t is 2.5mm, and degree of depth h is 0.35mm; The shape of cross section of spiral groove 2 is trapezoidal.

The mechanism of the lateral surface enforcing condensation heat transfer of two-sided strengthened heat-transfer pipe of the present utility model is: contrast plain tube, increased the area of condensation heat transfer, the inned coefficient of its lateral surface is about 3 times of plain tube; Special three-dimensional extended surface texture can be given full play to the condensate liquid surface tension effects, make wall continuous phase cause overheated or supercooled state promotion phase transformation, and the ratchet top helps to facilitate the continuous generation of condensate liquid, and rapidly from the ratchet overhead stream to the ratchet root, discharge from the pipe end under the effect of gravity, condensate liquid is less at the viscous flow angle at drainage point place simultaneously.

The mechanism that the lateral surface of two-sided strengthened heat-transfer pipe of the present utility model is strengthened convection heat transfer' heat-transfer by convection is: direction of flow is constantly changed special ratchet type wall and peel off in the boundary layer, the secondary stream (spiral flow and boundary layer separation flow) and little the revolving of bringing out have promoted the turbulent extent aggravation, have reduced the thickness and the thermal resistance of viscous flow bottom consumingly; The ratchet of helical form continuous distributed has been avoided the circumferential eddy flow of pipe stream vertically, and front and back have suppressed the formation of dead band, ratchet downstream and eddy current, the energy consumption that reduced the body resistance and caused in abutting connection with, ratchet with fluoran stream surface of curved surface.

The mechanism that the medial surface of two-sided strengthened heat-transfer pipe of the present utility model is strengthened convection heat transfer' heat-transfer by convection is: the secondary separation stream effect that the spiral grooves 2 of inside pipe wall causes, can increase substantially the heat transfer coefficient in the pipe, and pipe inter-spiral groove 2 has played secondary stream, so its scale inhibition ability strengthens.

In sum, the outer two-sided strengthened heat-transfer pipe of ratchet type of inside spin of the present utility model is specially adapted to strengthen Many components evaporate the vapour condensations and contain the steam-condensation of incoagulable gas. Have efficient, energy-conservation, heat transfer area is big With the characteristics that reduce tube wall incrustation. The high-low pressure that can be widely used in the fields such as electric power, chemical industry, refrigeration and the energy Backheat heating, condenser, water-cooled condenser, air cooler and oil cooler.

Claims

1. the outer two-sided strengthened heat-transfer pipe of ratchet type of an inside spin, the outer surface of tube wall that it is characterized in that heat-transfer pipe be provided with many vertically in the shape of a spiral the shape continuous distributed and with the incorporate curved surface ratchet-shaped of tube wall fin (1), adjoin each other between curved surface around each curved surface ratchet-shaped fin (1), its first helical angle A is 0.5 °～5 °, the second helical angle B is 15 °～23 °, and the high H of curved surface ratchet-shaped fin is 0.2mm～2.5mm; The heat-transfer pipe inwall is provided with spiral groove (2), and this spiral groove (2) number is 1～25, and helical pitch (or pitch) t is 1～450mm, and degree of depth h is 0.15mm～1.5mm.

2. intensify heat transfer pipe according to claim 1 is characterized in that the shape of cross section of the spiral groove (2) of heat-transfer pipe inwall is trapezoidal.

3. intensify heat transfer pipe according to claim 1 is characterized in that the shape of cross section of the spiral groove (2) of heat-transfer pipe inwall is a triangle.