Air preheater adopting wing streamline pipe

Abstract

The invention relates to an air preheater adopting wing streamline pipes, and belongs to the technical field of heat exchange equipment. Comprising a shell, an air tube box, an air inlet, an air outlet, a flue gas inlet, a flue gas outlet, two wing streamline tube bundles and two tube plates. The air inlet is formed in the upper portion of the front wall of the shell. The air outlet is formed below the front wall of the shell; the air pipe box is arranged on the rear wall of the shell; one tube plate is arranged at the air inlet; the other tube plate is arranged at the air outlet; each tube plate is correspondingly provided with one wing streamline tube bundle; the two wing streamline tube bundles are axially and horizontally arranged up and down; the inlet end of the upper wing streamline tube bundle is aligned with the air inlet, and the outlet end is butted with the air tube box; the inlet end of the lower wing streamline tube bundle is butted with the air tube box, and the outlet end is aligned with the air outlet; the flue gas inlet is formed in the bottom of the shell; the flue gas outlet is formed in the top of the shell; the problems of low heat exchange efficiency and large resistance in the prior art are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of heat exchange equipment and relates to an air preheater using a wing streamlined tube. Background Art

[0002] Air preheater is an important recovery equipment in industrial boilers and heating furnaces. Its function is to use the waste heat of flue gas to heat the air sent into the furnace, improve thermal efficiency and save fuel. At present, the air preheaters widely used in industry are mainly tubular preheaters and rotary preheaters. Among them, tubular preheaters are widely used due to their simple structure and easy maintenance. Traditional tubular air preheaters mostly use regular pipes such as round tubes as heat exchange elements. However, regular pipes such as round tubes have the following shortcomings:

[0003] (1) The heat exchange area per unit volume is small and the heat exchange efficiency is low;

[0004] (2) The airflow tends to form a stagnation zone on the outer wall of the circular tube, resulting in large resistance and reduced heat transfer coefficient;

[0005] (3) There is a large dead zone when the circular tubes are arranged, which reduces the compactness of the heat exchanger.

[0006] It is difficult to meet the demand of industrial production for high-efficiency, energy-saving and long-life air preheaters. Summary of the invention

[0007] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to propose an air preheater using a wing streamlined tube, and to solve the problems of low heat exchange efficiency and large resistance in the prior art.

[0008] The solution of the present invention is:

[0009] An air preheater using wing streamlined tubes comprises a shell, an air tube box, an air inlet, an air outlet, a smoke inlet, a smoke outlet, two wing streamlined tube bundles, and two tube sheets;

[0010] The shell is a rectangular shell structure placed vertically; the air inlet is arranged above the front wall of the shell; the air outlet is arranged below the front wall of the shell; the air pipe box is arranged on the rear wall of the shell; one tube sheet is arranged at the air inlet; the other tube sheet is arranged at the air outlet; each tube sheet is correspondingly installed with a wing streamlined tube bundle; the two wing streamlined tube bundles are axially arranged horizontally up and down; the inlet end of the wing streamlined tube bundle located above is aligned with the air inlet, and the outlet end is connected to the air pipe box; the inlet end of the wing streamlined tube bundle located below is connected to the air pipe box, and the outlet end is aligned with the air outlet; the smoke inlet is arranged at the bottom of the shell; the smoke outlet is arranged at the top of the shell.

[0011] In the above-mentioned air preheater using wing streamlined tubes, the air inlet, the wing streamlined tube bundle located above, the air tube box, the wing streamlined tube bundle located below, and the air outlet form a transverse U-shaped air flow channel; after the external cold air enters from the air inlet, it passes through the wing streamlined tube bundle located above, the air tube box, the wing streamlined tube bundle located below, and flows out from the air outlet in sequence.

[0012] In the above-mentioned air preheater using wing streamlined tubes, the external high-temperature flue gas enters the shell from the flue gas inlet, performs heat exchange on the two wing streamlined tube bundles in the inner cavity of the shell, and heats the cold air flowing in the wing streamlined tube bundles before being discharged from the flue gas outlet.

[0013] In the above-mentioned air preheater using wing streamlined tubes, the wing streamlined tube bundle is composed of multiple wing-shaped cross-section heat exchange tubes; the multiple wing-shaped cross-section heat exchange tubes are arranged in a staggered order; the staggered distances of the centerline rows and columns of adjacent wing-shaped cross-section heat exchange tubes are 20 mm and 40 mm respectively.

[0014] In the above-mentioned air preheater using wing streamlined tubes, the tube sheet is a plate-like structure; one tube sheet is installed above the front wall of the shell; the other tube sheet is installed below the front wall of the shell; the two tube sheets realize the sealing of the front wall of the shell; through holes corresponding to the cross-sectional shape of the wing-shaped cross-sectional heat exchange tube are arranged on the tube sheet, and the through holes are arranged in a staggered order; multiple wing-shaped cross-sectional heat exchange tubes corresponding to the wing streamlined tube bundle extend into the through holes; the external cold air is realized to flow in the wing streamlined tube bundle without mixing with the external high-temperature flue gas.

[0015] In the above-mentioned air preheater using a wing streamlined tube, the cross-sectional shape of the wing-shaped cross-section heat exchange tube is composed of a half ellipse and two arcs; the half ellipse is located at the bottom and opens upward; each opening side wall of the half ellipse is linearly connected to an arc; the two arcs intersect to form a top pointed structure;

[0016] The curve equation of a half ellipse is:

[0017] x 2 / 30 2 +y 2 / 7 2 =1

[0018] The curve equation of the arc is:

[0019] x 2 +y 2 =163 2 .

[0020] In the above-mentioned air preheater using a wing streamlined tube, the cross-sectional shape of the wing-shaped cross-section heat exchange tube is composed of a half ellipse, two circular arcs and an elliptical arc; the half ellipse is located at the bottom and opens upward; each opening side wall of the half ellipse is linearly connected to a circular arc; the elliptical arc opens downward, and each opening side wall of the elliptical arc is linearly connected to the top of a circular arc;

[0021] The curve equation of the half ellipse is:

[0022] x 2 / 30 2 +y 2 / 7 2 =1

[0023] The curve equation of the arc is:

[0024] x 2 +y 2 =163 2

[0025] The curve equation of the elliptical arc is:

[0026] x 2 / 29 2 +y 2 / 4 2 =1.

[0027] In the above-mentioned air preheater using a wing streamlined tube, a vortex generator is arranged on the inner wall of the wing-shaped cross-section heat exchange tube; the vortex generator is a spiral protrusion, and the vortex generator is evenly distributed along the axial direction of the wing-shaped cross-section heat exchange tube.

[0028] In the above-mentioned air preheater using wing streamlined tubes, the shell is made of carbon steel material; the wing-shaped cross-section heat exchange tube is made of carbon steel material.

[0029] In the above-mentioned air preheater using wing streamlined tubes, the manufacturing method of the wing streamlined tube bundle is:

[0030] Step 1: Determine the wing-shaped cross-section heat exchange tube and manufacturing method according to the design parameters;

[0031] Step 2: preparing a heat exchange tube with a wing-shaped cross section by an extrusion molding process;

[0032] Step 3, arranging a vortex generator in the heat exchange tube with a wing-shaped cross-section;

[0033] Step 4: assemble a plurality of processed heat exchange tubes with wing-shaped cross-sections into a wing streamlined tube bundle;

[0034] Step 5: Install the wing streamlined tube bundle into the shell.

[0035] The beneficial effects of the present invention compared with the prior art are:

[0036] (1) The wing streamlined tube design of the present invention has a larger heat exchange area, significantly reduces flow resistance, reduces dust accumulation in equipment, and improves heat exchange efficiency and energy saving effects;

[0037] (2) The wing-shaped cross-section heat exchange tubes of the present invention are arranged in a staggered order, which can ensure a compact structure while allowing the fluid to flow fully. This design breaks the flow boundary layer, enhances turbulent heat exchange, and reduces the dead zone area, thereby improving space utilization;

[0038] (3) The present invention has specially designed the shape of the heat exchange tube, which minimizes the airflow disturbance during the flue gas flow and enhances the turbulent heat exchange capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is an overall schematic diagram of the air preheater of the present invention.

[0040] Figure 2 This is a schematic diagram of the first form of the wing-shaped cross-section heat exchange tube of the present invention;

[0041] Figure 3 This is a schematic diagram of the second form of the wing-shaped cross-section heat exchange tube of the present invention;

[0042] Figure 4 It is a schematic diagram of the structure of the vortex generator of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the embodiments.

[0044] The invention provides an air preheater using a wing streamlined tube, which solves the problems of low heat exchange efficiency and large resistance in the prior art.

[0045] Air preheaters using wing streamlined tubes, such as Figure 1As shown, it specifically includes a shell 1, an air pipe box 2, an air inlet 3, an air outlet 4, a smoke inlet 5, a smoke outlet 6, two wing streamlined tube bundles 7, and two tube sheets 8. Among them, the shell 1 is a rectangular shell structure placed vertically; the air inlet 3 is arranged above the front wall of the shell 1; the air outlet 4 is arranged below the front wall of the shell 1; the air pipe box 2 is arranged at the rear wall of the shell 1; one tube sheet 8 is arranged at the air inlet 3; the other tube sheet 8 is arranged at the air outlet 4; each tube sheet 8 is correspondingly installed with a wing streamlined tube bundle 7; the two wing streamlined tube bundles 7 are axially arranged horizontally up and down; the inlet end of the wing streamlined tube bundle 7 located above is aligned with the air inlet 3, and the outlet end is docked with the air pipe box 2; the inlet end of the wing streamlined tube bundle 7 located below is docked with the air pipe box 2, and the outlet end is aligned with the air outlet 4; the smoke inlet 5 is arranged at the bottom of the shell 1; and the smoke outlet 6 is arranged at the top of the shell 1.

[0046] In the present invention, the shell 1 is made of carbon steel; the wing-shaped cross-section heat exchange tube 71 is made of carbon steel.

[0047] The air inlet 3, the wing streamlined tube bundle 7 located above, the air pipe box 2, the wing streamlined tube bundle 7 located below, and the air outlet 4 form a transverse U-shaped air flow channel; after the external cold air enters from the air inlet 3, it passes through the wing streamlined tube bundle 7 located above, the air pipe box 2, the wing streamlined tube bundle 7 located below, and flows out from the air outlet 4 in sequence.

[0048] The present invention arranges the air inlet at the upper part of the shell, and the air outlet at the lower part of the shell. The smoke inlet is arranged at the bottom of the shell, and the smoke outlet is arranged at the top of the shell. The countercurrent arrangement of the cold and hot fluids can increase the average temperature difference and enhance the heat exchange.

[0049] External high-temperature flue gas enters the shell 1 from the flue gas inlet 5, performs heat exchange with the two wing streamlined tube bundles 7 in the inner cavity of the shell 1, heats the cold air flowing in the wing streamlined tube bundle 7, and is then discharged from the flue gas outlet 6.

[0050] The wing streamlined tube bundle 7 is composed of a plurality of wing-shaped cross-section heat exchange tubes 71; the plurality of wing-shaped cross-section heat exchange tubes 71 are arranged in a staggered sequence; the staggered distances of the centerline rows and columns of adjacent wing-shaped cross-section heat exchange tubes 71 are 20 mm and 40 mm respectively.

[0051] The tube sheet 8 is a plate-like structure; one tube sheet 8 is installed above the front wall of the shell 1; the other tube sheet 8 is installed below the front wall of the shell 1; the two tube sheets 8 realize the sealing of the front wall of the shell 1; the tube sheet is provided with through holes corresponding to the cross-sectional shape of the wing-shaped cross-sectional heat exchange tube 71, and the through holes are arranged in a staggered order; multiple wing-shaped cross-sectional heat exchange tubes 71 corresponding to the wing streamlined tube bundle 7 extend into the through holes; the external cold air is realized to flow in the wing streamlined tube bundle 7 without mixing with the external high-temperature flue gas.

[0052] like Figure 2 As shown, the cross-sectional shape of the airfoil-shaped cross-section heat exchange tube 71 is composed of a half ellipse 711 and two arcs 712; the half ellipse 711 is located at the bottom and opens upward; each opening side wall of the half ellipse 711 is linearly connected to an arc 712; the two arcs 712 intersect to form a top pointed structure;

[0053] The curve equation of the half ellipse 711 is:

[0054] x 2 / 30 2 +y 2 / 7 2 =1

[0055] The curve equation of arc 712 is:

[0056] x 2 +y 2 =163 2 .

[0057] The front end of the pipe has a semi-elliptical cross-section, and the rear end forms a pointed tail through two curvature arcs to reduce fluid vortex and resistance.

[0058] like Figure 3 As shown, the cross-sectional shape of the airfoil-shaped cross-section heat exchange tube 71 is composed of a half ellipse 711, two arcs 712 and an elliptical arc 713; the half ellipse 711 is located at the bottom and opens upward; each opening side wall of the half ellipse 711 is linearly connected to an arc 712; the elliptical arc 713 opens downward, and each opening side wall of the elliptical arc 713 is linearly connected to the top of an arc 712;

[0059] The curve equation of the half ellipse 711 is:

[0060] x 2 / 30 2 +y 2 / 7 2 =1

[0061] The curve equation of arc 712 is:

[0062] x 2 +y 2 =1632

[0063] The curve equation of the elliptical arc 713 is:

[0064] x 2 / 29 2 +y 2 / 4 2 =1.

[0065] The front end of the pipe also adopts a semi-elliptical cross-section, and the rear end forms an arc-shaped tail through two circular arcs and a small elliptical arc to enhance the stability of fluid flow.

[0066] like Figure 4 As shown, a vortex generator 10 is provided on the inner wall of the heat exchange tube 71 with a wing-shaped cross section; the vortex generator 10 is a spiral protrusion, and the vortex generator 10 is evenly distributed along the axial direction of the heat exchange tube 71 with a wing-shaped cross section.

[0067] The manufacturing method of the wing streamlined tube bundle 7 is as follows:

[0068] Step 1: Determine the wing-shaped cross-section heat exchange tube 71 and the manufacturing method according to the design parameters;

[0069] Step 2: Prepare the wing-shaped cross-section heat exchange tube 71 by extrusion molding process;

[0070] Step 3: arranging a vortex generator 10 in the heat exchange tube 71 with a wing-shaped cross section;

[0071] Step 4: assemble a plurality of processed heat exchange tubes 71 with wing-shaped cross-sections into a wing streamlined tube bundle 7;

[0072] Step 5: Install the wing streamlined tube bundle 7 into the shell 1.

[0073] The shell 1 is square and is provided with an air pipe box 2. The material of the shell 1 can be carbon steel, and the wall thickness is determined according to the working pressure and temperature. The air pipe box 2 adopts an arc-shaped shell, which is used to connect the air inlet and outlet to allow air circulation. The air inlet 3 is arranged at the upper part of the shell 1 for inputting low-temperature air to be heated. The air outlet 4 is arranged at the lower part of the shell 1 for outputting the heated high-temperature air. The positions of the air inlet 3 and the air outlet 4 can be adjusted according to actual needs to achieve the best flow organization. The smoke inlet 5 is arranged at the bottom of the shell 1 for inputting high-temperature smoke discharged from the heating furnace. The smoke outlet 6 is arranged at the top of the shell 1 for outputting low-temperature smoke after heat transfer. The positions of the smoke inlet 5 and the smoke outlet 6 can also be adjusted according to actual needs.

[0074] The wing streamlined tube bundle 7 is arranged in the shell 1 and is composed of a plurality of wing-shaped cross-section heat exchange tubes 71. The wing-shaped cross-section heat exchange tubes include two designs: the first type is a tail-pointed tube composed of a half ellipse and two arcs, and the curve equation of the half ellipse is x 2 / 30 2 +y 2 / 7 2 =1, the curve equations of the two arcs are x 2 +y 2 =163 2 The front end of the pipe has a semi-elliptical cross-section, and the rear end forms a pointed tail through two curvature arcs to reduce fluid vortex and resistance; the other type is a tail arc wing tube composed of a half ellipse, two arcs and a small elliptical arc. The curve equation of the small elliptical arc is x 2 / 29 2 +y 2 / 4 2 =1, the front end of the pipe also adopts a semi-elliptical cross-section, and the rear end forms an arc tail through two arcs and a small elliptical arc to enhance the stability of fluid flow. The pipe is made of carbon steel, and the wall thickness is determined according to the actual situation. Carbon steel has good corrosion resistance and thermal conductivity.

[0075] like Figure 1 As shown, the wing streamlined tube bundle 7 is arranged in a staggered order, and the staggered distances between the centerline rows and columns of adjacent wing-shaped cross-section heat exchange tubes 71 are 20 mm and 40 mm respectively. This can ensure that the structure is compact while the fluid can flow fully. This design breaks the flow boundary layer, enhances turbulent heat exchange, and reduces the dead zone area, thereby improving space utilization.

[0076] like Figure 2 and Figure 3 As shown in the figure, the air preheater design with a pointed tail tube is suitable for boiler systems. This structure has very smooth streamlines in high-speed airflow and good tail coverage, showing low resistance and high heat exchange performance, and is suitable for equipment with high flow rate requirements. The air preheater design with a curved tail tube is suitable for applications that require stable airflow in chemical processes. This structure is suitable for efficient heat exchange at lower airflow speeds. If there is no particularly high flow rate, the heat exchange effects of the two types are similar, and the curved tail is easier to manufacture, so this type can be used for low flow rates.

[0077] like Figure 2 , 3As shown in Figure 4, the fluid streamline coverage of the two airfoil-shaped cross-section heat exchange tubes is much greater than that of round tubes or elliptical tubes. The airfoil-shaped cross-section tube can increase the contact area between the heat exchange tube and the fluid, that is, increase the heat exchange area and improve the heat exchange rate; on the other hand, the flow of the airfoil-shaped cross-section tube is smoother, effectively reducing the pressure drop, reducing the influence of flow resistance, improving the heat exchange effect, and not easy to accumulate dust, extending the service life.

[0078] Tube sheets 8 are arranged on both sides of the shell 1 to support and fix the wing streamlined tube bundle 7. In order to further improve the heat exchange efficiency in the tube, vortex generators 10, i.e., spiral grooves, are arranged on the inner wall of the wing streamlined tube bundle 7. Figure 4 As shown, the vortex generator 10 is a spiral protrusion, which is evenly distributed along the axial direction of the pipeline. The vortex generator 10 can enhance the turbulent heat exchange in the tube and improve the heat transfer coefficient.

[0079] The working principle of the present invention is as follows: the low-temperature air to be heated enters the wing streamlined tube bundle 7 at the upper part of the air preheater from the air inlet 3, then passes through the air pipe box 2 to reach the wing streamlined tube bundle at the lower part, and finally flows out from the air outlet 4. At the same time, the high-temperature flue gas enters the air preheater housing 1 from the flue gas inlet 5 at the bottom, passes through the wing streamlined tube bundle 7 for heat exchange, and finally is discharged from the flue gas outlet 6. Due to the use of technologies such as wing streamlined tube bundles, staggered arrangement and vortex generators, the heat exchange efficiency is significantly improved.

[0080] The manufacturing method of the air preheater of the present invention comprises the following steps: (1) determining the pipe material and manufacturing method according to the design parameters; (2) preparing the wing streamlined pipe by the extrusion molding process; (3) arranging a vortex generator in the pipe; (4) assembling a plurality of processed wing streamlined pipes into a pipe bundle; (5) installing the pipe bundle into the shell to complete the assembly of the air preheater.

[0081] The air preheater of the present invention has the advantages of compact structure, excellent heat transfer performance, low cost, etc. It is suitable for waste heat recovery systems of various industrial boilers and heating furnaces, can significantly improve the thermal efficiency of the system, achieve energy conservation and emission reduction, and has broad application prospects. In practical applications, the size and material of each component can be appropriately adjusted according to specific working conditions to obtain the best use effect.

[0082] The streamlined tube design of the wing has a larger heat exchange area, which significantly reduces flow resistance, reduces dust accumulation in equipment, and improves heat exchange efficiency and energy saving effects.

[0083] The wing streamlined tube bundles are arranged in a staggered order, which further improves the heat exchange efficiency and space utilization and reduces the manufacturing cost.

[0084] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An air preheater using a wing streamlined tube, characterized in that: It comprises a shell (1), an air pipe box (2), an air inlet (3), an air outlet (4), a smoke inlet (5), a smoke outlet (6), two wing streamlined tube bundles (7), and two tube sheets (8); The shell (1) is a rectangular shell structure placed vertically; the air inlet (3) is arranged above the front wall of the shell (1); the air outlet (4) is arranged below the front wall of the shell (1); the air pipe box (2) is arranged on the rear wall of the shell (1); one tube sheet (8) is arranged at the air inlet (3); the other tube sheet (8) is arranged at the air outlet (4); each tube sheet (8) is correspondingly installed with a wing streamlined tube bundle (7); the two wing streamlined tube bundles (7) are axially arranged horizontally up and down; the inlet end of the wing streamlined tube bundle (7) located at the top is aligned with the air inlet (3), and the outlet end is connected to the air pipe box (2); the inlet end of the wing streamlined tube bundle (7) located at the bottom is connected to the air pipe box (2), and the outlet end is aligned with the air outlet (4); the smoke inlet (5) is arranged at the bottom of the shell (1); and the smoke outlet (6) is arranged at the top of the shell (1).

2. The air preheater using wing streamlined tube according to claim 1, characterized in that: The air inlet (3), the wing streamlined tube bundle (7) located at the top, the air pipe box (2), the wing streamlined tube bundle (7) located at the bottom, and the air outlet (4) form a transverse U-shaped air flow channel; after the external cold air enters from the air inlet (3), it passes through the wing streamlined tube bundle (7) located at the top, the air pipe box (2), the wing streamlined tube bundle (7) located at the bottom in sequence, and flows out from the air outlet (4).

3. The air preheater using wing streamlined tube according to claim 2, characterized in that: The external high-temperature flue gas enters the shell (1) from the flue gas inlet (5), performs heat exchange with two wing streamlined tube bundles (7) in the inner cavity of the shell (1), heats the cold air flowing in the wing streamlined tube bundles (7), and then is discharged from the flue gas outlet (6).

4. The air preheater using wing streamlined tube according to claim 2, characterized in that: The wing streamlined tube bundle (7) is composed of a plurality of wing-shaped cross-section heat exchange tubes (71); the plurality of wing-shaped cross-section heat exchange tubes (71) are arranged in a staggered sequence; the staggered distances of the centerline rows and columns of adjacent wing-shaped cross-section heat exchange tubes (71) are 20 mm and 40 mm respectively.

5. The air preheater using wing streamlined tubes according to claim 4, characterized in that: The tube sheet (8) is a plate-like structure; one tube sheet (8) is installed above the front wall of the shell (1); the other tube sheet (8) is installed below the front wall of the shell (1); the two tube sheets (8) achieve sealing of the front wall of the shell (1); through holes corresponding to the cross-sectional shape of the wing-shaped cross-sectional heat exchange tube (71) are provided on the tube sheet, and the through holes are arranged in a staggered order; a plurality of wing-shaped cross-sectional heat exchange tubes (71) corresponding to the wing streamlined tube bundle (7) extend into the through holes; and external cold air flows in the wing streamlined tube bundle (7) without mixing with external high-temperature flue gas.

6. The air preheater using wing streamlined tubes according to claim 4, characterized in that: The cross-sectional shape of the wing-shaped cross-section heat exchange tube (71) is composed of a half ellipse (711) and two circular arcs (712); the half ellipse (711) is located at the bottom and opens upward; each opening side wall of the half ellipse (711) is linearly connected to a circular arc (712); the two circular arcs (712) intersect to form a top pointed structure; The curve equation of the half ellipse (711) is: x 2 / 30 2 +y 2 / 7 2 =1 The curve equation of the arc (712) is: x 2 +y 2 =163 2 。 7. The air preheater using wing streamlined tubes according to claim 4, characterized in that: The cross-sectional shape of the airfoil-shaped cross-section heat exchange tube (71) consists of a half ellipse (711), two circular arcs (712) and an elliptical arc (713); the half ellipse (711) is located at the bottom and opens upward; each opening side wall of the half ellipse (711) is linearly connected to a circular arc (712); the elliptical arc (713) opens downward, and each opening side wall of the elliptical arc (713) is linearly connected to the top of a circular arc (712); The curve equation of the half ellipse (711) is: x 2 / 30 2 +y 2 / 7 2 =1 The curve equation of the arc (712) is: x 2 +y 2 =163 2 The curve equation of the elliptical arc (713) is: x 2 / 29 2 +y 2 / 4 2 =1。 8. The air preheater using wing streamlined tubes according to claim 4, characterized in that: A vortex generator (10) is arranged on the inner wall of the wing-shaped cross-section heat exchange tube (71); the vortex generator (10) is a spiral protrusion, and the vortex generator (10) is evenly distributed along the axial direction of the wing-shaped cross-section heat exchange tube (71).

9. The air preheater using wing streamlined tubes according to claim 1, characterized in that: The shell (1) is made of carbon steel; the heat exchange tube (71) with a wing-shaped cross-section is made of carbon steel.

10. The air preheater using wing streamlined tubes according to claim 4, characterized in that: The manufacturing method of the wing streamlined tube bundle (7) is as follows: Step 1: Determine the wing-shaped cross-section heat exchange tube (71) and the manufacturing method according to the design parameters; Step 2: preparing a heat exchange tube (71) with a wing-shaped cross-section by an extrusion molding process; Step 3: arranging a vortex generator (10) in the heat exchange tube (71) with a wing-shaped cross-section; Step 4: assembling a plurality of processed wing-shaped cross-section heat exchange tubes (71) into a wing streamlined tube bundle (7); Step 5: Install the wing streamlined tube bundle (7) into the shell (1).

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