Boiler heat exchange tube

Abstract

The utility model relates to the technical field of boiler devices, in particular to a boiler heat exchange tube, which comprises a finned tube and a sleeve sleeved outside the finned tube, the finned tube consists of four groups of fin units and four arc-shaped plates, the fin units are circumferentially arrayed along the axis of the sleeve, the arc-shaped plates are connected with the fin units, each fin unit comprises a plurality of parallel fins, and the arc-shaped plates are connected with the fin units. The fins are arranged at equal intervals, the interval is A, the heights of the fins are gradually increased and then decreased in the clockwise direction of the sleeve, the interval between a straight line L which is parallel to the fins and passes through the circle center of the sleeve and the highest fin is half of the interval A, and the distance between the top ends of the highest fins in adjacent fin units is equal to the interval A; the fins among the four fin units are matched with one another to form a plurality of L-shaped channels distributed in the radial direction of the sleeve, the corners of the L-shaped channels are communicated with the adjacent L-shaped channels, and the temperature difference between high-temperature gas in the center and high-temperature gas at the edge is small, so that the heat conductivity coefficient can be effectively increased, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler devices, in particular to a boiler heat exchange tube. Background Art

[0002] A U.S. patent document with publication number US20060201451A1 discloses a pipe of a combustion boiler, which is used to transport high-temperature gases produced by combustion and heat water outside the pipe. The pipe includes a wall with a constant thickness along its entire length and at least one arc-shaped support member, a plurality of fins extending from the arc-shaped support member, and the arc-shaped support member is in contact with the inner surface of the wall.

[0003] In the above patent, multiple groups of fins cooperate to form multiple curved channels along the radial direction of the pipe, and the channels are not connected. Since the heat of the gas close to the pipe wall is conducted to the outside of the pipe faster, the gas temperature at the center of the pipe is higher than the gas temperature near the pipe wall. Therefore, the efficiency of conducting the heat of the gas at the center of the pipe to the outside of the pipe is low. Utility Model Content

[0004] The utility model provides a boiler heat exchange tube, aiming to solve the problem of low efficiency of gas heat conduction from the center of the pipeline to the outside of the pipeline in the related technology.

[0005] A boiler heat exchange tube comprises a fin tube and a sleeve sleeved outside the fin tube, the fin tube comprises four groups of fin units arranged in a circular array along the axis of the sleeve and four arc-shaped plates connecting the fin units, the fin unit comprises a plurality of parallel fins, the fins are equally spaced and the spacing is A, the height of the fins gradually increases and then decreases along the clockwise direction of the sleeve, the spacing between a straight line L parallel to the fins and passing through the center of the sleeve and the highest fin is half of the spacing A, and the distance between the top ends of the highest fins in adjacent fin units is equal to the spacing A, the fins between the four fin units cooperate with each other to form a plurality of L-shaped channels arranged along the radial direction of the sleeve, and the L-shaped channels are connected with adjacent L-shaped channels at the corners.

[0006] Preferably, the side surfaces of the fins are provided with wave-shaped grooves.

[0007] Preferably, the fins gradually become thicker from top to bottom.

[0008] Preferably, a groove is formed at one end of the arc-shaped plate, and a protrusion matching with the groove is provided at the other end.

[0009] Preferably, an elastic metal strip is arranged in the groove, and after the protrusion is inserted into the groove, when the elastic metal strip is not compressed, there is a gap between the end surfaces of the two arc-shaped plates that are close to each other.

[0010] Preferably, the fin tube and the sleeve are interference fit.

[0011] Preferably, the minimum distance between two vertical fins at the corner of the L-shaped channel is distance B, and the ratio between distance B and spacing A is 0.7-1.

[0012] By adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0013] During use, the fins penetrate deep into the high-temperature gas, dividing the high-temperature gas into multiple branches that enter each L-shaped channel respectively. The gap between each fin is the space for gas flow. After the gas passes through, the gas can be quickly cooled, and the L-shaped channels are interconnected to allow multiple branches to mix with each other. Therefore, the temperature difference between the high-temperature gas at the center and the high-temperature gas at the edge is small, so the heat transfer coefficient can be effectively improved, thereby improving the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the fin arrangement in the utility model.

[0015] Figure 2 It is a structural schematic diagram of the arc plate positioning structure in the utility model.

[0016] Figure 3 It is a structural schematic diagram of another arc plate positioning structure in the utility model.

[0017] Reference numerals:

[0018] 1. Sleeve; 2. Fin; 3. Arc plate; 3a. Groove; 31. Protrusion; 32. Elastic metal strip. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0020] like Figure 1 As shown, a boiler heat exchange tube comprises a fin tube and a sleeve 1 sleeved outside the fin tube, and the fin tube and the sleeve 1 are interference fit.

[0021] The fin tube is composed of four groups of fin units arranged in a circumferential array along the axis of the sleeve 1 and four arc-shaped plates 3 connecting the fin units;

[0022] The fin unit includes a plurality of parallel fins 2, and the fins 2 are equally spaced and the spacing is A. The height of the fins 2 gradually increases and then decreases in the clockwise direction of the sleeve 1, that is, the figure formed by the lines between the ends of the fins 2 is roughly fan-shaped. A straight line L is drawn that is parallel to the fins 2 and passes through the center of the sleeve 1. The spacing between the straight line L and the highest fin 2 is half of the spacing A, and the distance between the top ends of the highest fins 2 in adjacent fin units is equal to the spacing A, that is, the lines between the breakpoints of the four highest fins 2 form a square with a side length of A.

[0023] The fins 2 between the four fin units cooperate with each other to form a plurality of L-shaped channels arranged radially along the sleeve 1, and are connected with adjacent L-shaped channels at the corners of the L-shaped channels. The minimum distance between the two vertical fins 2 at the corners of the L-shaped channels is shown as distance B, and the ratio between distance B and spacing A is 0.7-1. During use, the fins 2 penetrate deep into the high-temperature gas, and divide the high-temperature gas into a plurality of branches that enter each L-shaped channel respectively. The gaps between the fins 2 are spaces for gas flow. After the gas passes through, the gas can be quickly cooled, and the L-shaped channels are interconnected to allow the plurality of branches to mix with each other. Therefore, the temperature difference between the high-temperature gas at the center and the high-temperature gas at the edge is small, so the heat transfer coefficient can be effectively improved, thereby improving the heat transfer efficiency.

[0024] like Figure 1 and Figure 2 As shown, the shape of the arc plate 3 is 1 / 4 of a circle, and four arc plates 3 are positioned and assembled into a complete circle through concave and convex grooves. A groove 3a is provided at one end of the arc plate 3, and a protrusion 31 matching the groove 3a is provided at the other end, so that the arc plate 3 eliminates the gap through the longitudinal edges of the groove 3a and the protrusion 31 plugged into each other, and is absolutely sealed and compacted together to prevent exhaust gas or condensate from flowing through. Most of the fins 2 in the fin unit are located on one arc plate 3, and the other part of the fins 2 are located on the adjacent arc plate 3;

[0025] like Figure 3 As shown, in another embodiment, an elastic metal strip 32 is provided in the groove 3a, and the metal strip is provided along the length direction of the sleeve 1 and is wavy. After the protrusion 31 is inserted into the groove 3a, when the elastic metal strip 32 is not compressed, there is a gap between the end surfaces of the two arc plates 3 that are close to each other. When high-temperature gas is introduced, the arc plates 3 expand due to heat, so the protrusion 31 squeezes the elastic metal strip 32, causing the elastic metal strip 32 to be flattened, so that the protrusion 31 is completely inserted into the groove 3a, thereby adapting to the thermal shock of the high-temperature airflow and avoiding thermal deformation of the arc plates 3.

[0026] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A boiler heat exchange tube, comprising a fin tube and a sleeve (1) sleeved outside the fin tube, characterized in that: The fin tube is composed of four groups of fin units arranged in a circular array along the axis of a sleeve (1) and four arc-shaped plates (3) connecting the fin units. The fin units include a plurality of parallel fins (2). The fins (2) are equally spaced and the spacing is A. The height of the fins (2) gradually increases and then decreases in the clockwise direction of the sleeve (1). The spacing between a straight line L parallel to the fins (2) and passing through the center of the sleeve (1) and the highest fin (2) is half of the spacing A. The distance between the top ends of the highest fins (2) in adjacent fin units is equal to the spacing A. The fins (2) between the four fin units cooperate with each other to form a plurality of L-shaped channels arranged radially along the sleeve (1). The L-shaped channels are connected to adjacent L-shaped channels at the corners. The minimum distance between two vertical fins (2) at the corners of the L-shaped channels is distance B. The ratio between distance B and spacing A is 0.7-1.

2. The boiler heat exchange tube according to claim 1, characterized in that: The side surfaces of the fins (2) are provided with wave-shaped grooves.

3. The boiler heat exchange tube according to claim 2, characterized in that: The fin (2) gradually becomes thicker from top to bottom.

4. The boiler heat exchange tube according to claim 1, characterized in that: A groove (3a) is provided at one end of the arc-shaped plate (3), and a protrusion (31) matching the groove (3a) is provided at the other end.

5. The boiler heat exchange tube according to claim 4, characterized in that: An elastic metal strip (32) is arranged in the groove (3a); after the protrusion (31) is inserted into the groove (3a), when the elastic metal strip (32) is not compressed, a gap exists between the end surfaces of the two arc-shaped plates (3) that are close to each other.

6. The boiler heat exchange tube according to claim 1, characterized in that: The fin tube and the sleeve (1) are interference fit.

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