CN113983851A

CN113983851A - Heat transfer pipe with transition surface on fin

Info

Publication number: CN113983851A
Application number: CN202111365834.9A
Authority: CN
Inventors: 王志军; 袁贵业; 李前方; 张小广; 夏瑞华; 安鹏涛; 巴栋杰
Original assignee: Xinxiang Longxiang Precision Copper Pipe Co ltd
Current assignee: Xinxiang Longxiang Precision Copper Pipe Co ltd
Priority date: 2021-11-18
Filing date: 2021-11-18
Publication date: 2022-01-28

Abstract

The heat transfer tube with the transition surface comprises a tube body and main fins which are integrally formed, wherein the main fins are wound on the outer surface of the tube body in a spiral mode, channels are formed between the adjacent main fins, the tops of the main fins are knurled to form grooves and primary fins, the tops of the primary fins are rolled or rolled to form flat fins, the flat fins and the primary fins form mushroom-shaped structures or T-shaped structures, the top surfaces of the flat fins are table tops, and the table tops are connected with at least one side wall surface of each flat fin through transition surfaces. The transition surface can guide the refrigerant boiling gas to be discharged out of the channel, and simultaneously guide the external refrigerant liquid to enter the channel, so that the refrigerant can regularly enter and exit, and a two-phase flow field in the channel and at the transition surface is improved, thereby greatly improving the boiling heat exchange effect.

Description

Heat transfer pipe with transition surface on fin

Technical Field

The invention relates to a heat transfer pipe, in particular to a heat transfer pipe with a transition surface on a fin.

Background

For the heat exchange tube manufacturing industry, the energy efficiency of refrigeration and air conditioning equipment is improved mainly by developing a high-efficiency heat transfer tube to improve the heat exchange efficiency of a heat exchanger. Especially, the heat resistance of the evaporating pipe used in the refrigeration and air conditioning system is quite large when the refrigerant boils outside the pipe, even larger than the heat resistance of the forced convection heat exchange inside the pipe, therefore, the heat transfer performance of the evaporating pipe can be improved by strengthening the boiling heat exchange outside the pipe.

Studies on the nucleate boiling mechanism show that: the heat exchange capacity of the evaporating tube can be improved by forming fins on the outer surface of the heat transfer tube. In the prior art, the heat exchange capacity can be improved by improving the inner surface of the evaporating tube which is contacted with the cooling medium. One example of modifying the inner surface of the heat exchange tube is a method of forming ridges on the inner surface of the heat exchange tube. The prior art has also enhanced heat transfer by modifying the fin structure, such as by grooving or grooving the fins on the outer surface of the tubes to form nucleate boiling cavities or voids, which structure allows the gas bubbles to pass outwardly through the cavities to or through narrower surface openings. Further, as the heat exchange tubes for evaporators disclosed in chinese patents CN95246323.7 and CN03207498.0, the outer surface is formed with T-shaped spiral fins pressed on the top to form a groove structure or a cavity structure with a slightly smaller opening, so as to form a location for forming a vaporization core, thereby achieving the effect of enhancing boiling heat exchange.

There is still a need for improvement of the sheet structure to enhance the external boiling heat transfer for improving the heat transfer performance of the evaporator tube.

Disclosure of Invention

In response to the needs in the art, the present invention provides a heat transfer tube with a fin having a transition surface.

A heat transfer pipe with transition surfaces on fins comprises a pipe body and main fins which are integrally formed, wherein the main fins are spirally wound on the outer surface of the pipe body, channels are formed between the adjacent main fins, the tops of the main fins are knurled to form grooves and primary fins, and the heat transfer pipe is characterized in that: the top of the primary fin is rolled or rolled to form a flat fin, the flat fin and the primary fin form a mushroom-shaped structure or a T-shaped structure, the top surface of the flat fin is a table top, and the table top is connected with at least one side wall surface of the flat fin through a transition surface.

Further: the transition surface is an inclined surface or an arc surface.

Further: the width of the transition surface is 0.05 mm-0.5 mm.

Further: the lowest end of the transition surface is lower than the side wall of the adjacent flat fin close to the lowest end, so that the refrigerant boiling gas is better guided to be discharged out of the channel, and meanwhile, the external refrigerant liquid is guided to enter the channel.

Further: the lowest end of the transition surface is covered by the side wall part of the adjacent flat fin close to the lowest end, and a gap is reserved, so that the refrigerant boiling gas is better guided to be discharged out of the channel, and meanwhile, the external refrigerant liquid is guided to enter the channel.

Further: 26 to 60 main fins are arranged along the axial direction of the tube body per inch, and the helical angle is 0.3 to 2.5 degrees.

Further: 60-160 grooves are distributed along the circumferential direction of the pipe body.

Further: the inner surface of the pipe body is provided with inner teeth, the inner teeth are in a thread shape, the axial cross section of the inner teeth is trapezoidal, and the tooth crest angle range of the inner teeth is 10-120 degrees.

Further: the included angle range of the inner teeth and the axis of the pipe body is 20-70 degrees, 6-90 inner teeth are distributed along the circumferential direction of the pipe body, and the height of the inner teeth is 0.1-0.6 mm.

Further: the main fins are obliquely arranged relative to the axial direction of the pipe body.

The invention has the beneficial effects that: 1. the transition surface can guide the refrigerant boiling gas to be discharged out of the channel, and the phenomenon that the overheating requirement of the gas refrigerant in the channel is increased due to overhigh pressure is avoided.

2. The transition surface can guide external refrigerant liquid into the channel, and dry evaporation caused by insufficient refrigerant in the channel is avoided.

3. The transition surface can guide the refrigerant boiling gas to be discharged out of the channel, and simultaneously guide the external refrigerant liquid to enter the channel, so that the refrigerant can regularly enter and exit, and a two-phase flow field in the channel and at the transition surface is improved, thereby greatly improving the boiling heat exchange effect.

Drawings

FIG. 1 is a schematic cross-sectional view of a first embodiment of the present invention;

FIG. 2 is a schematic front view showing the structure of a main fin and a flattened fin in the first embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a second embodiment of the present invention;

fig. 4 is a schematic front view of a main fin and a flat fin in a third embodiment of the present invention.

In the figure, 1, a tube body; 2. a primary fin; 3. internal teeth; 4. a channel; 5. a groove; 6. primary fins; 7. a flat fin; 8. a table top; 9. a transition surface.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings. Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention. The terms of orientation such as left, center, right, up, down, etc. in the examples of the present invention are only relative to each other or are referred to the normal use state of the product, and should not be considered as limiting.

The first embodiment:

a heat transfer tube with transition surface fin, as shown in fig. 1 and fig. 2, comprising a tube body 1 and primary fins 2 which are integrally formed, wherein the primary fins 2 are spirally wound on the outer surface of the tube body 1, channels 4 are formed between the adjacent primary fins 2, the tops of the primary fins 2 are knurled to form grooves and primary fins 6, the tops of the primary fins 6 are rolled or rolled to form flat fins 7, the flat fins 7 and the primary fins 6 form a mushroom-shaped structure or a T-shaped structure, the top surfaces of the flat fins 7 are table surfaces 8, and the table surfaces 8 are flat or approximately flat; the table top 8 is connected with at least one side wall surface of the flat fin 7 through a transition surface 9, the transition surface 9 is an inclined surface or an arc surface, the transition surface 9 can guide the refrigerant boiling gas to be discharged out of the channel 4, and simultaneously guide the external refrigerant liquid to enter the channel 4, so that the refrigerant can regularly enter and exit, and a two-phase flow field in the channel 4 and at the transition surface 9 is improved, thereby greatly improving the boiling heat exchange effect; the width of the transition surface 9 is 0.05 mm-0.5 mm; the lowest end of the transition surface 9 is lower than one side wall of the adjacent flat fin 7 close to the lowest end.

In addition, 26 to 60 main fins 2 are arranged per inch along the axial direction of the tube body 1, and the helical angle is 0.3 to 2.5 degrees. 60 to 160 grooves are distributed in the groove 5 along the circumferential direction of the pipe body 1. The inner surface of the pipe body 1 is provided with inner teeth 3, the inner teeth 3 are in a thread shape, the axial cross section of each inner tooth 3 is trapezoidal, and the crest angle range of each inner tooth 3 is 10-120 degrees. The included angle range of the inner teeth 3 and the axis of the pipe body 1 is 20-70 degrees, 6-90 inner teeth 3 are distributed along the circumferential direction of the pipe body 1, and the height of the inner teeth 3 is 0.1-0.6 mm.

Second embodiment:

other technical characteristics in the same manner as in the first embodiment, as shown in fig. 3, the heat exchange tube has an outer diameter of 19mm and a wall thickness of 1.13mm, and a dedicated tube rolling mill is used and is integrally formed inside and outside the tube by extrusion. The main fin 2 is bent or inclined in advance before the primary fin 6 is rolled or rolled, that is, the main fin 2 is inclined relative to the axial direction of the tube body 1, then the flat fin 7 is formed by rolling or rolling the top of the primary fin 6, a transition surface 9 is arranged between the table top 8 and at least one side surface of the table top 8, as shown in fig. 4, the width of the transition surface 9 on one side of the flat fin 7 is larger, the width of the transition surface 9 on the other side of the flat fin 7 is smaller, and the transition surface 9 is connected with the table top 8.

The third embodiment:

other technical features in the same manner as in the first or second embodiment, the lowermost end of the transition surface 9 is covered with a portion of the side wall of the adjacent flat fin 7 near the lowermost end with a gap.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A heat transfer tube with a transition surface with fins, comprising an integrally formed tube body and main fins, the main fins are helically wound on the outer surface of the tube body, and the adjacent main fins are formed between Channel, the top of the main fin is knurled to form grooves and primary fins, characterized in that: the top of the primary fins is rolled or flattened to form flat fins, the flat fins and all The primary fins form a mushroom-shaped structure or a T-shaped structure, the top surface of the flat fins is a table surface, and the table surface and at least one side wall surface of the flat fins are connected by a transition surface.

2 . The finned heat transfer tube with transition surface according to claim 1 , wherein the transition surface is an inclined surface or a circular arc surface. 3 .

3 . The finned heat transfer tube with transition surface according to claim 1 , wherein the transition surface has a width of 0.05 mm to 0.5 mm. 4 .

4 . The finned heat transfer tube with transition surface according to claim 1 , wherein the lowest end of the transition surface is lower than the side wall of the adjacent flat fin near the lowest end. 5 . .

5 . The heat transfer tube with fins with transition surfaces according to claim 1 , wherein the lowest end of the transition surface is surrounded by a side wall portion of the adjacent flat fins that is close to the lowest end. 6 . Cover and leave gaps.

6 . The heat transfer tube with fins with transition surfaces according to claim 1 , wherein the main fins are provided with 26 to 60 fins per inch along the axial direction of the tube body, and the helix angle is 0.3°. 7 . ~2.5°.

7 . The finned heat transfer tube with transition surface according to claim 1 , wherein 60 to 160 grooves are distributed along the circumferential direction of the tube body. 8 .

8 . The heat transfer tube with fins with transition surfaces according to claim 1 , wherein the inner surface of the tube body is provided with internal teeth, the internal teeth are threaded, and the inner teeth are threaded. 9 . The axial section is trapezoidal, and the tip angle of the inner teeth ranges from 10° to 120°.

9 . The finned heat transfer tube with transition surface according to claim 8 , wherein the included angle between the inner teeth and the axis of the tube body ranges from 20° to 70°, and the inner teeth There are 6 to 90 pieces distributed along the circumferential direction of the pipe body, and the height of the inner teeth is 0.1 mm to 0.6 mm.

10 . The heat transfer tube with fins and transition surfaces according to claim 1 , wherein the main fins are inclined relative to the axial direction of the tube body. 11 .