CN114046684A

CN114046684A - Heat transfer pipe for enhancing boiling

Info

Publication number: CN114046684A
Application number: CN202111399644.9A
Authority: CN
Inventors: 李前方; 王志军; 安鹏涛; 张小广; 王大同; 袁贵业; 夏瑞华
Original assignee: Xinxiang Longxiang Precision Copper Pipe Co ltd
Current assignee: Xinxiang Longxiang Precision Copper Pipe Co ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-02-15

Abstract

A heat transfer tube for enhancing boiling 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, a channel is formed between every two adjacent main fins, the tops of the main fins are knurled to form grooves and primary fins, the primary fins are rolled or rolled to form surface fins, at least one end of each surface fin protrudes outwards to form an extension fin, the extension fins are connected with at least one position of each surface fin in a reverse curve mode, the top end of one extension fin on each surface fin is marked as an end A, the end A on each surface fin is located between every two surface fins adjacent to the surface fins and forms a first straight line and a second straight line with the ends A of the two surface fins respectively, and the included angle of the first straight line and the included angle of the second straight line range is 30-60 degrees. The extension fins are positioned between the two adjacent surface fins, so that the refrigerant gas is more easily blocked in the boiling channel between the two surface fins, and the effects of reducing the boiling superheat degree and increasing the boiling are achieved.

Description

Heat transfer pipe for enhancing boiling

Technical Field

The invention relates to a heat transfer pipe, in particular to a boiling-enhanced heat transfer pipe.

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, in the evaporating pipe used in the refrigeration and air-conditioning system, the boiling heat transfer thermal resistance of the refrigerant when the refrigerant boils outside the pipe is larger, even larger than the thermal resistance of the forced convection heat transfer inside the pipe, therefore, the strengthening of the boiling heat transfer outside the pipe can play a significant role in improving the heat transfer performance of the evaporating pipe.

Studies on the nucleate boiling mechanism show that: the heat exchange capacity of the evaporating pipe can be improved by forming fins on the outer surface of the heat transfer pipe by the copper pipe. For example, the heat exchange tubes for evaporators disclosed in chinese patents CN95246323.7 and CN03207498.0 have top portions pressed with T-shaped helical fins to form a groove structure or a cavity structure with a slightly smaller opening to form a location for forming a vaporization core, thereby achieving an effect of enhancing boiling heat exchange.

There is a need to optimize the fin structure on the outer surface of the heat transfer tube for improving the heat transfer effect of evaporation boiling.

Disclosure of Invention

In response to the needs in the art, the present invention provides an enhanced boiling heat transfer tube.

A heat transfer tube for enhancing boiling comprises a tube body and primary fins, wherein the tube body and the primary fins are integrally formed, the primary fins are spirally wound on the outer surface of the tube body, channels are formed between the adjacent primary fins, the tops of the primary fins are knurled to form grooves and primary fins, and the primary fins are rolled or flattened to form surface fins, and the heat transfer tube is characterized in that: at least one end of the surface fin protrudes outwards to form an extension fin, the extension fin is connected with at least one position of the surface fin in a reverse curve mode, the top end of one extension fin on the surface fin is marked as an end A, the end A on the surface fin is positioned between two adjacent surface fins of the surface fin and forms a first straight line and a second straight line with the ends A of the two adjacent surface fins respectively, the included angle range of the first straight line and the second straight line is 30-60 degrees, and a gap is reserved between the extension fin and the adjacent surface fin.

Further: the extended fins span the through slots and extend into the grooves.

Further: the inner arc-shaped side edge on the extending fin and the outer arc-shaped side edge on the adjacent surface fin are corresponding to and close to each other, so that the surface of the groove is sealed and blocked more tightly.

Further: the normal distance between the extension fins and the fins on the adjacent surfaces of the periphery is 0.01 mm-0.5 mm.

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 in the radial direction of the pipe body is 0.1-0.6 mm.

Further: the surface fins are provided with two extension fins, the two extension fins of the surface fins are distributed in an array of 180 degrees by taking the center point of the two extension fins as the center of a circle, the top end of one extension fin is the end A, the top end of the other extension fin is the end B, the end B on the surface fin is positioned between the other two adjacent surface fins and forms a third straight line and a fourth straight line with the ends B of the two surface fins respectively, the included angle range of the third straight line and the fourth straight line is 30-60 degrees, and the included angle of the third straight line and the fourth straight line is the same as the included angle of the first straight line and the second straight line.

The invention has the beneficial effects that: 1. the extension fins are positioned between the two adjacent surface fins, so that the refrigerant gas is more easily blocked in the boiling channel between the two surface fins, and the effects of reducing the boiling superheat degree and increasing the boiling are achieved.

2. The gaps between the extended fins and the adjacent fins are small, so that the refrigerant gas is prevented from escaping from the gaps.

3. The top ends of the extended fins and the adjacent fins on the periphery form a refrigerant escape outlet at the groove, so that the vaporized refrigerant regularly escapes from the escape outlet, a two-phase flow field in the channel is improved, and the boiling heat exchange effect is greatly improved.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is an enlarged schematic view of region B in FIG. 1;

FIG. 3 is a schematic structural diagram of a second embodiment of the present invention;

fig. 4 is an enlarged schematic structural view of a region C in fig. 3.

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 surface fin; 71. extending the fins; 81. a first straight line; 82. a second straight line; 83. a third straight line; 84. a fourth straight line.

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 boiling-enhanced heat transfer tube is disclosed, 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, the primary fins 2 are provided with 26 to 60 per inch along the axial direction of the tube body 1, the helix angle is 0.3 to 2.5 °, a channel 4 is formed between the adjacent primary fins 2, the top of each primary fin 2 is knurled to form a groove 5 and a primary fin 6, the groove 5 is distributed with 60 to 160 along the circumferential direction of the tube body 1, the primary fins 6 are rolled or rolled to form a surface fin 7, at least one end of each surface fin 7 protrudes outwards to form an extended fin 71, the extended fin 71 is connected with at least one position of the surface fins 7 in a reverse curve, the top end of one extended fin 71 on the surface fin 7 is denoted as an a end, and the a end on the surface fin 7 is located between two surface fins 7 adjacent to the surface fin 7 and is respectively connected with the two surface fins 7 A first straight line 81 and a second straight line 82 are formed between the ends A of the face fins 7, the included angle range of the first straight line 81 and the second straight line 82 is 30-60 degrees, a gap is reserved between the extension fin 71 and the adjacent face fins 7, and the normal distance between the extension fin 71 and the adjacent face fins 7 at the periphery is 0.01-0.5 mm.

Wherein, the extension fin 71 crosses the through slot 4 and extends into the groove 5, and the inner arc-shaped side edge on the extension fin 71 and the outer arc-shaped side edge on the adjacent surface fin 7 are corresponding to and close to each other. 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 in the radial direction of the pipe body 1 is 0.1-0.6 mm.

Second embodiment:

other technical features are that, under the same condition as the first embodiment, as shown in fig. 3 and 4, two extension fins 71 are provided on the surface fin 7, the two extension fins 71 of the surface fin 7 are distributed in an array of 180 ° around their center points, the top end of one of the extension fins 71 is the a end, the top end of the other extension fin 71 is the B end, the B end of the surface fin 7 is located between the other two surface fins 7 adjacent to the surface fin 7 and forms a third straight line 83 and a fourth straight line 84 with the B ends of the two surface fins 7, the included angle between the third straight line 83 and the fourth straight line 84 ranges from 30 ° to 60 °, and the included angle between the third straight line 83 and the fourth straight line 84 is the same as the included angle between the first straight line 81 and the second straight line 82.

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 for enhancing boiling comprises a tube body and primary fins, wherein the tube body and the primary fins are integrally formed, the primary fins are spirally wound on the outer surface of the tube body, channels are formed between the adjacent primary fins, the tops of the primary fins are knurled to form grooves and primary fins, and the primary fins are rolled or flattened to form surface fins, and the heat transfer tube is characterized in that: at least one end of the surface fin protrudes outwards to form an extension fin, the extension fin is connected with at least one position of the surface fin in a reverse curve mode, the top end of one extension fin on the surface fin is marked as an end A, the end A on the surface fin is positioned between two adjacent surface fins of the surface fin and forms a first straight line and a second straight line with the ends A of the two adjacent surface fins respectively, the included angle range of the first straight line and the second straight line is 30-60 degrees, and a gap is reserved between the extension fin and the adjacent surface fin.

2. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: the extended fins span the through slots and extend into the grooves.

3. An enhanced boiling heat transfer tube as set forth in claim 2, wherein: the inner arc-shaped side edge on the extension fin and the outer arc-shaped side edge on the surface fin adjacent to the inner arc-shaped side edge on the extension fin correspond to and are close to each other.

4. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: the normal distance between the extension fins and the fins on the adjacent surfaces of the periphery is 0.01 mm-0.5 mm.

5. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: 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.

6. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: 60-160 grooves are distributed along the circumferential direction of the pipe body.

7. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: 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.

8. An enhanced boiling heat transfer tube as set forth in claim 1, wherein: 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 in the radial direction of the pipe body is 0.1-0.6 mm.

9. An enhanced boiling heat transfer tube as claimed in any one of claims 1 to 8, wherein: the surface fins are provided with two extension fins, the two extension fins of the surface fins are distributed in an array of 180 degrees by taking the center point of the two extension fins as the center of a circle, the top end of one extension fin is the end A, the top end of the other extension fin is the end B, the end B on the surface fin is positioned between the other two adjacent surface fins and forms a third straight line and a fourth straight line with the ends B of the two surface fins respectively, the included angle range of the third straight line and the fourth straight line is 30-60 degrees, and the included angle of the third straight line and the fourth straight line is the same as the included angle of the first straight line and the second straight line.