Symmetrical inclined finned tube bundle and flue gas waste heat recovery heat exchanger

Abstract

The invention relates to a symmetrical inclined finned tube bundle and a flue gas waste heat recovery heat exchanger, and belongs to the field of waste heat recovery. Comprising a plurality of finned tubes arranged in an array mode, each finned tube comprises a base tube and a plurality of fins, the fins are arranged at intervals in the axial direction of the base tube and fixedly arranged on the base tube in a sleeving mode, the fins are obliquely arranged relative to the axial direction of the base tube, and every two adjacent fins of each finned tube are symmetrically arranged. The relation among heat transfer enhancement, ash deposition control and flow resistance optimization is balanced from the angle of flow field collaboration, and efficient and stable operation of the flue gas waste heat recovery heat exchanger is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of waste heat recovery, and in particular to a symmetrical inclined fin tube bundle and a flue gas waste heat recovery heat exchanger. Background Art

[0002] As global energy shortages become increasingly severe, energy conservation and consumption reduction in the industrial sector have become crucial for achieving sustainable development. Statistics show that industrial energy consumption accounts for over 70% of total energy consumption, with 30%-50% of this energy lost as waste heat from flue gases. Flue gas waste heat recovery technology, which recycles this heat through efficient heat exchange devices, can significantly improve energy efficiency and reduce carbon emissions, thus playing a strategic role in promoting green manufacturing.

[0003] Traditional flue gas waste heat recovery devices mostly use smooth tube bundle heat exchangers, but they rely primarily on heat conduction through the tube wall and convection heat transfer. These devices suffer from technical bottlenecks such as low convection heat transfer coefficients and limited heat exchange area, resulting in bulky equipment and difficulty in achieving high recovery efficiency. To enhance heat transfer, existing technologies have developed heat transfer enhancement elements such as spiral finned tubes and H-shaped finned tubes. Spiral finned tubes effectively improve the heat transfer coefficient by increasing the surface area (with an expansion ratio of up to 3-5 times) and inducing fluid rotation. However, the continuous spiral structure easily forms flue gas vortex zones, resulting in fly ash particle deposition rates as high as 15%-20%. Although H-shaped finned tubes reduce the tendency to ash accumulation through longitudinal fins, their orthogonal fin structure significantly increases flow resistance, seriously affecting the economic efficiency of system operation. Engineering practice has shown that existing finned tube technology has not yet effectively solved the problem of synergizing heat transfer enhancement with ash accumulation control and flow resistance optimization, which has restricted the efficient and stable operation of flue gas waste heat recovery devices. The deeper technical contradiction lies in the fact that the existing fin tube bundle design fails to balance the coupling relationship between heat transfer enhancement, dust accumulation suppression and pressure drop control from the perspective of flow field synergy. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a symmetrical inclined fin tube bundle and a flue gas waste heat recovery heat exchanger to solve the above problems.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a symmetrically inclined fin tube bundle, comprising a plurality of fin tubes arranged in an array, wherein the fin tubes include a base tube and a plurality of fins, wherein the plurality of fins are spaced apart along the axial direction of the base tube and fixedly sleeved on the base tube, the fins are arranged at an angle relative to the axial direction of the base tube, and two adjacent fins of the fin tubes are arranged symmetrically.

[0006] The beneficial effects of the present invention are as follows: compared with the smooth tube bundles, spiral finned tubes and H-shaped finned tubes in the prior art, the fins symmetrically and obliquely arranged on the base tubes in the present invention can, on the one hand, guide the flue gas flow to change its flow direction, so that the flue gas flow can be separated and counteracted when passing through the fins, thereby forming a flow field morphology of multiple longitudinal vortex flows between the tube bundles according to the flow direction of the flue gas, which is conducive to enhancing the mutual mixing between the fluid in the area between the base tubes and the thermal boundary layer fluid near the outer wall of the tube bundle, making the thermal boundary layer near the outer wall of the tube bundle thinner, and ultimately achieving effective improvement in heat exchange performance; on the other hand, the flow field morphology of multiple longitudinal vortex flows formed between the tube bundles is conducive to forming a pressure drop in the area between the base tubes, and at the same time, the inclined fins have the characteristic of low flow resistance, which is conducive to removing dust accumulated on the base tube and the outer wall of the fins, and is conducive to inhibiting the formation of dust accumulation. From the perspective of flow field synergy, the present invention balances the relationship between heat transfer enhancement, dust accumulation control and flow resistance optimization.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the angle between the fin and the flue gas flow direction is between 15° and 75°, and the sum of the angle between the fin and the flue gas flow direction and the angle between the fin and the axial direction of the base tube is 90°.

[0009] The beneficial effect of adopting the above further solution is that it is conducive to making the flue gas flow direction perpendicular to the base tube, thereby adjusting the synergistic relationship between heat transfer enhancement, dust accumulation control and flow resistance optimization according to the different inclination angles of the fins.

[0010] Furthermore, in one of the base tubes, the center distance between two adjacent fins is between half and three times the outer diameter of the base tube.

[0011] The beneficial effect of adopting the above further solution is that by limiting the relationship between the center distance between two adjacent fins and the outer diameter of the base tube, it is helpful to avoid interference between the fins and the adjacent fins when the fins are tilted.

[0012] Furthermore, the fins and the base tube are fixedly connected via an arc transition.

[0013] The beneficial effect of adopting the above further solution is that it is conducive to forming a smooth connection between the fins and the base tube, and avoiding the accumulation of smoke dust in the flue gas at the connection between the base tube and the fins.

[0014] Furthermore, the base tube is a circular or elliptical tubular structure.

[0015] The beneficial effect of adopting the above further solution is that it is beneficial to use the circular or elliptical structure to prevent smoke dust in the smoke from accumulating on the base pipe.

[0016] Furthermore, the fin is an elliptical plate-shaped structure, and the axial orthographic projection contour of the fin is a circle.

[0017] The beneficial effect of adopting the above further solution is that it is beneficial to utilize the elliptical structure of the fins to prevent smoke dust in the flue gas from accumulating on the base pipe.

[0018] Furthermore, the outer diameter of the fin's axial orthographic projection profile is larger than the outer diameter of the base tube and smaller than the center distance between two adjacent base tubes.

[0019] The beneficial effect of adopting the above further solution is that it helps to avoid interference between the fins on one base tube and the fins on another adjacent base tube.

[0020] Furthermore, the fin is a rectangular plate-shaped structure, and the axial orthographic projection profile of the fin is a square.

[0021] The beneficial effect of adopting the above further solution is that it is conducive to adjusting the shape of the fin according to different usage scenarios and requirements, thereby increasing the applicability of the present invention.

[0022] Furthermore, the side length of the axial orthographic projection profile of the fin is greater than the outer diameter of the base tube and smaller than the center distance between two adjacent base tubes.

[0023] The beneficial effect of adopting the above further solution is that it helps to avoid interference between the fins on one base tube and the fins on another adjacent base tube.

[0024] Another technical solution of the present invention to solve the above technical problem is as follows: a flue gas waste heat recovery heat exchanger, comprising any of the above-mentioned symmetrical inclined fin tube bundles.

[0025] The beneficial effect of the present invention is that the symmetrical inclined fin tube bundle is arranged in the flue gas waste heat recovery heat exchanger, which is conducive to the efficient and stable operation of the flue gas waste heat recovery heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a symmetrically inclined fin tube bundle provided in Example 1 of the present invention;

[0027] Figure 2 A side view of a symmetrical inclined fin tube bundle provided in Example 1 of the present invention;

[0028] Figure 3 A schematic structural diagram of a symmetrically inclined finned tube bundle provided in the second embodiment of the present invention;

[0029] Figure 4 A side view of a symmetrical inclined fin tube bundle provided in the second embodiment of the present invention;

[0030] Figure 5 A front view of a symmetrical inclined fin tube bundle provided by an embodiment of the present invention;

[0031] Figure 6 This is a flow field morphology diagram provided by Example 5 of the present invention;

[0032] Figure 7 Graph showing changes in heat transfer coefficient and flow pump power with air flow rate for Example 5 of the present invention and Comparative Example 1;

[0033] Figure 8 Graph showing changes in heat transfer coefficient and flow pump power with air flow rate for Example 5 of the present invention and Comparative Example 2;

[0034] Figure 9 Graph showing the variation of heat transfer coefficient and flow pump power with air flow rate for Example 5 and Comparative Example 3 of the present invention.

[0035] in, Figures 1 to 5 The downward arrow in the middle indicates the direction of smoke flow. Figure 2 D1 in the figure represents the outer diameter of the axial orthographic projection profile of the fin 2. Figure 4 a in the equation represents the side length of the axial orthographic projection of the fin 2. Figure 5 Where α represents the angle between the fin 2 and the incoming flue gas flow direction, β represents the angle between the fin 2 and the axial direction of the base tube 1, D represents the outer diameter of the base tube 1, L represents the center distance between two adjacent base tubes 1, and p represents the center distance between two adjacent fins 2.

[0036] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0037] 1. Base tube; 2. Fins. DETAILED DESCRIPTION

[0038] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0039] Example 1.

[0040] like Figures 1 to 5 As shown, a symmetrical inclined fin tube bundle includes a plurality of fin tubes arranged in an array, wherein the fin tubes include a base tube 1 and a plurality of fins 2, wherein the plurality of fins 2 are spaced apart along the axial direction of the base tube 1 and fixedly sleeved on the base tube 1, and the fins 2 are arranged inclined relative to the axial direction of the base tube 1, and two adjacent fins 2 of the fin tube are arranged symmetrically.

[0041] It should be noted that: in the technical solution of the present invention, "a plurality of fin tubes arranged in an array" means that a plurality of fin tubes are arranged in the horizontal and vertical directions of the array, that is, a plurality of fin tubes are stacked up and down, and each layer has a plurality of coplanar fin tubes, such as Figures 1 to 4 As shown, there are two layers, upper and lower, and each layer has two coplanar fin tubes, the axes of the multiple fin tubes are parallel to each other, and in the multi-layer structure, the upper and lower adjacent layers can be coaxially arranged, that is, the upper structure is directly above the lower structure, or can be staggered, that is, the upper structure is directly above the lower structure and is offset by a certain distance, and both the upper structure and the lower structure have multiple coplanar fin tubes; in addition, in a preferred embodiment of the present invention, "a plurality of fin tubes arranged in an array" can also refer to a plurality of fin tubes being arranged in the transverse or longitudinal direction of the array, that is, the plurality of fin tubes only form one layer in the transverse or longitudinal direction, and in a single-layer structure, two adjacent fin tubes can be coaxially arranged or staggered;

[0042] Understanding of fluid separation: when smoke flows, because the fins 2 are tilted, the fins 2 will separate the smoke, forming a separation of the smoke; Understanding of fluid counter-flow: when smoke flows, because the fins 2 are tilted, when the state between the two adjacent fins 2 is that the angle close to the direction of smoke flow is greater than the angle away from the direction of smoke flow, that is, the opening close to the direction of smoke flow is larger than the opening away from the direction of smoke flow, the smoke flow enters between the two adjacent fins 2 through the larger opening and is discharged from the smaller opening. When discharged, the opening is reduced, which will form a counter-flow of smoke.

[0043] The beneficial effects of this embodiment are as follows: compared with the smooth tube bundles, spiral finned tubes, and H-shaped finned tubes in the prior art, the fins symmetrically and obliquely arranged on the base tubes in the present invention can, on the one hand, guide the incoming flue gas flow to change its flow direction, so that the incoming flue gas flow can achieve fluid separation and counteraction when passing through the fins, thereby forming a flow field morphology of multiple longitudinal vortex flows between the tube bundles according to the flow direction of the flue gas, which is conducive to enhancing the mutual mixing between the fluid in the area between the base tubes and the thermal boundary layer fluid near the outer wall of the tube bundle, thinning the thermal boundary layer near the outer wall of the tube bundle, and ultimately achieving an effective improvement in heat exchange performance; on the other hand, the flow field morphology of the multiple longitudinal vortex flows formed between the tube bundles is conducive to forming a pressure drop in the area between the base tubes. At the same time, the low flow resistance of the inclined fins is conducive to removing dust accumulated on the base tubes and the outer wall of the fins, and is conducive to suppressing the formation of dust accumulation. From the perspective of flow field synergy, the present invention balances the relationship between heat transfer enhancement, dust accumulation control, and flow resistance optimization.

[0044] Preferably, Figure 5As shown, the angle α between the fin 2 and the flue gas flow direction is between 15° and 75°, and the sum of the angle α between the fin 2 and the flue gas flow direction and the angle β between the fin 2 and the axial direction of the base tube 1 is 90°.

[0045] It should be noted that, in the technical solution of the present invention, the angle α between the fin 2 and the incoming flue gas flow direction varies within a range of 15°≤α≤75°.

[0046] The beneficial effect of adopting the above preferred solution is that it is conducive to making the flue gas flow direction perpendicular to the base tube, thereby adjusting the synergistic relationship between heat transfer enhancement, dust accumulation control and flow resistance optimization according to the different inclination angles of the fins.

[0047] Preferably, in one base tube 1 , the center distance p between two adjacent fins 2 is between half and three times the outer diameter D of the base tube 1 .

[0048] It should be noted that, in the technical solution of the present invention, the center distance p between two adjacent fins 2 varies in the range of 0.5D≤p≤3D.

[0049] The beneficial effect of adopting the above preferred solution is that by limiting the relationship between the center distance between two adjacent fins and the outer diameter of the base tube, it is helpful to avoid interference between the fins and the adjacent fins when the fins are tilted.

[0050] Preferably, the fins 2 and the base tube 1 are fixedly connected via an arc transition.

[0051] The beneficial effect of adopting the above preferred solution is that it is conducive to forming a smooth connection between the fins and the base tube, and avoiding the accumulation of smoke dust in the flue gas at the connection between the base tube and the fins.

[0052] Preferably, the base pipe 1 is a circular or elliptical tubular structure.

[0053] The beneficial effect of adopting the above preferred solution is that it is beneficial to use the circular or elliptical structure to prevent smoke dust in the smoke from accumulating on the base pipe.

[0054] Example 2.

[0055] On the basis of the first embodiment, the fin 2 is an elliptical plate-shaped structure, and the axial orthographic projection contour of the fin 2 is a circle.

[0056] The beneficial effect of adopting the above solution is that it is beneficial to utilize the elliptical structure of the fins to prevent smoke dust in the flue gas from accumulating on the base pipe.

[0057] Preferably, Figure 2As shown, the outer diameter D1 of the axial orthographic projection profile of the fin 2 is larger than the outer diameter D of the base tube 1 and smaller than the center distance L between two adjacent base tubes 1 .

[0058] It should be noted that when the base tube 1 is an elliptical tubular structure, the outer diameter D of the base tube 1 is half of the sum of the major axis and the minor axis of the ellipse.

[0059] The beneficial effect of adopting the above preferred solution is that it helps to avoid interference between the fins on one base tube and the fins on another adjacent base tube.

[0060] Example 3.

[0061] Based on the first embodiment, the fin 2 is a rectangular plate-shaped structure, and the axial orthographic projection profile of the fin 2 is a square.

[0062] The beneficial effect of adopting the above solution is that it is conducive to adjusting the shape of the fin according to different usage scenarios and requirements, thereby increasing the applicability of the present invention.

[0063] Preferably, Figure 4 As shown, the side length a of the axial orthographic projection profile of the fin 2 is greater than the outer diameter D of the base tube 1 and smaller than the center distance L between two adjacent base tubes 1 .

[0064] The beneficial effect of adopting the above preferred solution is that it helps to avoid interference between the fins on one base tube and the fins on another adjacent base tube.

[0065] Example 4.

[0066] This embodiment provides a flue gas waste heat recovery heat exchanger, comprising the symmetrical inclined fin tube bundle described in any one of Embodiments 1 to 3.

[0067] The beneficial effect of this embodiment is that the symmetrically inclined finned tube bundle is arranged in the flue gas waste heat recovery heat exchanger, which is conducive to the efficient and stable operation of the flue gas waste heat recovery heat exchanger.

[0068] The present invention will be described below through several comparative experiments:

[0069] Example 5.

[0070] Use the periodic method to intercept Figure 1The numerical simulation is performed on the repeating unit shown in the figure. There are four base tubes 1 in the unit arranged in two horizontal and two vertical patterns. The base tube 1 is a circular tubular structure. The center distance L between any two adjacent base tubes 1 is selected as 100 mm. The outer diameter D of the base tube 1 is selected as 50 mm. The fin 2 is elliptical. The diameter D1 of the fin 2 projected in the axial direction of the base tube 1 is selected as 74 mm. The angle α between the fin 2 and the flue gas flow direction is selected as 45°. The center distance p between two adjacent fins 2 of two phases on the same base tube 1 is 100 mm. The fins 2 are symmetrically inclined in the axial direction of the base tube 1. Air is selected as the heat transfer fluid. The inner wall surface of the base tube 1 is set to a fixed heat flux density, that is, the heat flux on the inner wall surface of the base tube 1 is fixed.

[0071] Comparison example 1.

[0072] The overall structure of the comparative example 1 is identical to that of the embodiment 5 except that the fins 2 are not present, that is, the comparative example 1 is a smooth tube bundle structure.

[0073] Commercial CFD (Computational Fluid Dynamics) software, such as Fluent, was used to simulate the heat exchange performance and flow pump work of Example 5 and Comparative Example 1, wherein the flow pump was used to drive the incoming flue gas flow.

[0074] The flow field morphology of Example 5 is as follows Figure 6 As shown, under the guidance of the symmetrically inclined fins 2, a flow field morphology of multiple longitudinal vortex flows is formed between the tube bundles. This flow field morphology is conducive to fluid mixing, that is, it is conducive to enhancing the mutual mixing between the fluid in the area between the base tubes 1 and the thermal boundary layer fluid near the outer wall of the tube bundle, making the thermal boundary layer near the outer wall of the tube bundle thinner, and ultimately enhancing the convective heat transfer performance, thereby effectively improving the heat exchange performance.

[0075] The heat transfer coefficient and flow pump work of Example 5 and Comparative Example 1 vary with air flow rate as shown in the figure below: Figure 7 As shown, according to Figure 7 It can be seen that with the increase of flow rate, the heat transfer coefficients of Example 5 and Control Example 1 gradually increase, and the heat transfer coefficient of Example 5 is 1.27-1.31 times that of Control Example 1. With the increase of flow rate, the flow pump work of Example 5 and Control Example 1 gradually increases, and the flow pump work of Example 5 is 3.18-3.70 times that of Control Example 1. According to common knowledge in the field, the higher the flow pump work, the higher the pressure drop, and thus the greater the flow resistance. That is to say, compared with Control Example 1, although the flow resistance of Example 5 is larger and the dust accumulation suppression effect is slightly worse, the heat exchange performance of Example 5 is better.

[0076] Comparative example 2.

[0077] The overall structure of the comparative example 2 is identical to that of the embodiment 5 except that the fins 2 are spiral. That is, the comparative example 2 is a spiral tube bundle structure.

[0078] The heat transfer coefficient and flow pump power of Example 5 and Comparative Example 2 vary with air flow rate as shown in the figure below: Figure 8 As shown, according to Figure 8 It can be seen that with the increase of flow rate, the heat transfer coefficients of Example 5 and Control Example 2 gradually increase, and the heat transfer coefficient of Example 5 is 0.75-0.78 times that of Control Example 2; with the increase of flow rate, the flow pump work of Example 5 and Control Example 2 gradually increases, and the flow pump work of Example 5 is 0.61-0.62 times that of Control Example 2. According to common knowledge in the art, the higher the flow pump work, the higher the pressure drop, and thus the greater the flow resistance. That is to say, compared with Control Example 2, although the heat exchange performance of Example 5 is slightly worse, the flow resistance of Example 5 is smaller and the dust accumulation inhibition effect is better.

[0079] Comparison example three.

[0080] The overall structure of the comparative example 3 is identical to that of the embodiment 5 except that the fin 2 is H-shaped, that is, the comparative example 3 is a spiral tube bundle structure.

[0081] The heat transfer coefficient and flow pump work of Example 5 and Comparative Example 3 are shown as follows: Figure 9 As shown, according to Figure 9 It can be seen that with the increase of flow rate, the heat transfer coefficients of Example 5 and Control Example 3 gradually increase, and the heat transfer coefficient of Example 5 is 0.81-0.84 times that of Control Example 3; with the increase of flow rate, the flow pump work of Example 5 and Control Example 3 gradually increases, and the flow pump work of Example 5 is 0.71-0.72 times that of Control Example 3. According to common knowledge in the art, the higher the flow pump work, the higher the pressure drop, and thus the greater the flow resistance. That is to say, compared with Control Example 3, although the heat exchange performance of Example 5 is slightly worse, the flow resistance of Example 5 is smaller and the dust accumulation inhibition effect is better.

[0082] In summary, the present invention arranges the fins 2 symmetrically and tilted in the axial direction of the base tube 1. Compared with the spiral tube bundle structure in the second comparative example and the spiral tube bundle structure in the third comparative example, although the present invention reduces the number of fins 2, resulting in slightly worse heat exchange performance, the flow resistance of the present invention is smaller and the dust accumulation suppression effect is better; compared with the smooth tube bundle structure in the first comparative example, the present invention arranges the fins 2, resulting in better heat exchange performance, but the flow resistance is relatively large and the dust accumulation suppression effect is slightly worse.

[0083] The present invention evaluates the flue gas waste heat recovery heat exchanger from two aspects: heat exchange performance and dust accumulation suppression effect. In the prior art, the dust accumulation suppression effect is good for a structure with poor heat exchange performance, such as the smooth tube bundle structure in control example one, and the dust accumulation suppression effect is poor for a structure with good heat exchange performance, such as the spiral tube bundle structure in control example two and the spiral tube bundle structure in control example three. The advantage of the present invention lies in balance. That is, the present invention forms a flow field morphology of multiple longitudinal vortex flows between the tube bundles, thereby balancing the relationship between heat transfer enhancement, dust accumulation control, and flow resistance optimization from the perspective of flow field synergy, so that the heat exchange performance and the dust accumulation suppression effect reach a balanced state, that is, to a certain extent, it meets both the heat exchange performance requirements of the flue gas waste heat recovery heat exchanger and the dust accumulation suppression effect of the flue gas waste heat recovery heat exchanger.

[0084] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0085] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0086] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0087] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0088] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0089] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A symmetrical inclined fin tube bundle, characterized in that: The invention comprises a plurality of fin tubes arranged in an array, wherein the fin tubes comprise a base tube (1) and a plurality of fins (2), wherein the plurality of fins (2) are spaced apart along the axial direction of the base tube (1) and are fixedly sleeved on the base tube (1), wherein the fins (2) are arranged obliquely relative to the axial direction of the base tube (1), and two adjacent fins (2) of the fin tubes are symmetrically arranged.

2. A symmetrical inclined fin tube bundle according to claim 1, characterized in that: The angle between the fin (2) and the incoming flue gas flow direction is between 15° and 75°, and the sum of the angle between the fin (2) and the incoming flue gas flow direction and the angle between the fin (2) and the axial direction of the base tube (1) is 90°.

3. The symmetrical inclined fin tube bundle according to claim 1, characterized in that: The center distance between two adjacent fins (2) of the finned tube is between half the outer diameter of the base tube (1) and three times the outer diameter of the base tube (1).

4. The symmetrical inclined fin tube bundle according to claim 1, characterized in that: The fin (2) and the base tube (1) are fixedly connected via an arc transition.

5. The symmetrical inclined fin tube bundle according to any one of claims 1 to 4, characterized in that: The base tube (1) is a circular or elliptical tubular structure.

6. The symmetrical inclined fin tube bundle according to claim 5, characterized in that: The fin (2) is an elliptical plate-shaped structure, and the axial orthographic projection profile of the fin (2) is circular.

7. The symmetrical inclined fin tube bundle according to claim 6, characterized in that: The outer diameter of the axial orthographic projection profile of the fin (2) is greater than the outer diameter of the base tube (1) and smaller than the center distance between two adjacent base tubes (1).

8. The symmetrical inclined fin tube bundle according to claim 5, characterized in that: The fin (2) is a rectangular plate-shaped structure, and the axial orthographic projection profile of the fin (2) is a square.

9. The symmetrical inclined fin tube bundle according to claim 8, characterized in that: The side length of the axial orthographic projection profile of the fin (2) is greater than the outer diameter of the base tube (1) and smaller than the center distance between two adjacent base tubes (1).

10. A flue gas waste heat recovery heat exchanger, characterized in that: The invention comprises the symmetrical inclined fin tube bundle according to any one of claims 1 to 9.

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