Composite Archimedes spiral type drag reduction device for improving air entraining performance of heavy duty gas turbine

Abstract

The invention discloses a composite Archimedes spiral type drag reduction device for improving the air entraining performance of a heavy duty gas turbine. The composite Archimedes spiral type drag reduction device comprises an upper-stage rotating disc, a middle-stage rotating disc and a lower-stage rotating disc. An air inlet gap is reserved between the outer circumferential surfaces of the upper-stage rotating disc and the middle-stage rotating disc, and an air outlet gap is formed in the bottom of the lower-stage rotating disc; a high-position disc cavity is formed between the side wall of the upper-stage rotating disc and the side wall of the middle-stage rotating disc, a low-position vortex reduction device disc cavity is formed between the side wall of the middle-stage rotating disc and the side wall of the lower-stage rotating disc, and an Archimedes spiral type flow guide plate is further arranged in the low-position vortex reduction device disc cavity; a vortex reduction hole is formed in a drum of the intermediate rotating disc, and a preset included angle is formed between the axis of the vortex reduction hole and the axis of the intermediate rotating disc; and the air inlet seam, the high-position disc cavity, the vortex reducing hole, the low-position vortex reducing device disc cavity and the air outlet seam are communicated to form an air flow passage. The vortex reduction holes are reasonably formed, the relative tangential speed of air is effectively reduced, the Archimedes spiral flow guide plate is matched, the low-radius free vortex loss of the air is reduced, and the resistance reduction performance of an air system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heavy gas turbine internal air system design, and particularly relates to a composite Archimedes spiral type drag reduction device for improving the performance of a heavy gas turbine bleed air. BACKGROUND

[0002] A gas turbine is a high-efficiency and reliable engine. It is widely used in various fields, such as aviation, shipping, vehicles, and generator sets. In the aviation field, the gas turbine is widely used as an aero-engine in various aircraft. In the shipping field, the gas turbine is widely used as a main engine in large ships and yachts. In the vehicle field, the gas turbine is used as a car engine or diesel engine replacement in high-performance vehicles and electric vehicles. In the generator set field, the gas turbine is used to build large power stations or as a small generator set in distributed energy systems. Its performance is an important indicator of the advancement of modern industry, and the key way to improve the performance of the gas turbine is to increase the inlet gas temperature before the turbine. However, with the development of gas turbine technology, the inlet temperature has already exceeded the temperature limit of the turbine blade, and secondary flow air system must be used to cool it to ensure the normal work of the high-temperature components.

[0003] To improve the quality of cooling air, an important measure is to reduce the drag of the air system bleed air source. When the cooling air passes through the radial bleed air structure from the root of the compressor blade, the air will be affected by centrifugal force, Coriolis force and other factors, resulting in a sharp drop in bleed air pressure and a decrease in the quality of secondary flow cooling air. To solve this problem, the common method is to add various vortex suppressor elements in the rotating disc cavity to suppress complex vortex and reduce the loss along the way, or to optimize and improve the drum bleed air element to reduce the loss of air through the hole. This kind of drag reduction method has been widely used in light turbine machinery, especially in aero-engines. However, due to the structural characteristics of heavy gas turbine bleed air structure, which is different from light turbine machinery, the previous research results cannot be directly applied. Therefore, there is an urgent need for a vortex reduction device that can improve the drag reduction performance of heavy gas turbine air system. SUMMARY

[0004] The present application provides an Archimedes spiral type drag reduction device for improving the performance of a heavy gas turbine bleed air, which solves the problems of insufficient drag reduction and inconvenient installation of traditional vortex reduction structure caused by the long travel characteristics of gas turbine bleed air. On the one hand, two different drag reduction structures are introduced to reduce the drag together. On the other hand, an advanced Archimedes spiral type guide vane drag reduction structure is used in the low position area to further improve the drag reduction performance.

[0005] Technical solution: To solve the above problems, the application adopts a composite Archimedes spiral type drag reduction device for improving the performance of air system pressure drop reduction of heavy gas turbine, which comprises a senior rotating disc, an intermediate rotating disc and a lower rotating disc, drum barrels are arranged on the senior rotating disc, the intermediate rotating disc and the lower rotating disc, and the three rotating discs are fixedly connected through the drum barrels; an air inlet gap is left between the outer circumferential surface of the senior rotating disc and the intermediate rotating disc, and an air outlet gap is arranged at the bottom of the lower rotating disc; vortex reduction holes are arranged on the intermediate rotating disc, and Archimedes spiral type guide plates are arranged on the lower rotating disc.

[0006] The side wall of the senior rotating disc close to the intermediate rotating disc, the side wall of the intermediate rotating disc close to the senior rotating disc, the upper surface of the drum barrel of the senior rotating disc and the upper surface of the drum barrel of the intermediate rotating disc surround to form a high-position disc cavity; the side wall of the intermediate rotating disc close to the lower rotating disc, the side wall of the lower rotating disc close to the intermediate rotating disc, the lower surface of the drum barrel of the intermediate rotating disc and the lower surface of the drum barrel of the lower rotating disc surround to form a low-position vortex reducer disc cavity; and an Archimedes spiral type guide plate is further arranged in the low-position vortex reducer disc cavity to guide the airflow out of the vortex reduction holes to the air outlet gap.

[0007] The drum barrel of the intermediate rotating disc is provided with vortex reduction holes, and the air inlet gap, the high-position disc cavity, the vortex reduction holes, the low-position vortex reducer disc cavity and the air outlet gap are connected to form an airflow passage; the axis of the vortex reduction holes and the axis of the intermediate rotating disc form a preset angle to ensure the communication between the high-position disc cavity and the low-position vortex reducer disc cavity.

[0008] Further, the preset angle is 20-70°.

[0009] Further, the inlet rotating radius r i of the vortex reduction holes is smaller than the outer radius r b of the intermediate rotating disc.

[0010] Further, the outlet rotating radius r o of the vortex reduction holes is greater than the inner radius r a of the intermediate rotating disc.

[0011] Further, the Archimedes spiral type guide plate comprises mutually perpendicular main plates and bottom plates, the bottom plates are fixed on the lower rotating disc, the main plates are perpendicular to the disc surface of the lower rotating disc, and the main plates are arranged along the radial direction of the lower rotating disc; and the profile line of one reference guide plate satisfies the Archimedes spiral line relationship, i.e. r=aΘ, 0<Θ<π / 2, 2r d / π d a<10r , and the profile lines of other guide plates can be obtained from the array of the reference guide plate; the bottom plates (42) are fixed on the lower rotating disc (3), and the main plates (41) are perpendicular to the disc surface of the lower rotating disc (3).

[0012] Further, the highest point r d of the main plate in the radial direction of the rotating disc is greater than the inner radius r of the intermediate rotating disc.The vortex-reducing hole is higher than the outlet of the vortex-reducing hole to guide the airflow out of the air gap.

[0013] Further, the lower rotating disc is provided with a fixed groove on the side wall close to the middle rotating disc, and the bottom plate is installed in the fixed groove through bolts.

[0014] Further, the number of the Archimedes spiral guide plates is greater than 1.

[0015] Further, the rotating shaft passes through the central holes of the upper rotating disc, the middle rotating disc and the lower rotating disc, the inner diameters of the upper rotating disc and the middle rotating disc are equal, and the upper rotating disc, the middle rotating disc and the rotating shaft are fixedly connected, and the air gap is left between the lower rotating disc and the rotating shaft.

[0016] Further, the cross section of the high disc cavity is rectangular, circular or any polygon.

[0017] Further, the cross section of the vortex-reducing hole is circular, elliptical, square or any polygon.

[0018] Beneficial effect: Compared with the prior art, the present application has the remarkable advantages that the relative tangential velocity of air is effectively reduced by reasonably arranging the vortex-reducing hole, the Archimedes spiral guide plate is used in cooperation, the highest point of the Archimedes spiral guide plate in the radial direction is higher than the outlet of the vortex-reducing hole, the airflow flows out more smoothly, the low radius free vortex loss of air is reduced, and the air system drag reduction performance is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a whole structure schematic view of the vortex-reducing device of the present application;

[0020] Figure 2 It is a circumferential section schematic view of the middle rotating disc of the present application;

[0021] Figure 3 It is a structure schematic view of the Archimedes spiral guide plate of the present application;

[0022] Figure 4 It is a structure schematic view of the Archimedes spiral guide plate installed in the lower rotating disc of the present application.

[0023] Figure 5 It is a structure schematic view of the middle rotating disc and the lower rotating disc of the present application. DETAILED DESCRIPTION

[0024] As Figure 1As shown, the Archimedes spiral type drag reduction device for improving the performance of heavy gas turbine bleed air in the embodiment. Including the upper rotating disc 1, the middle rotating disc 2, the lower rotating disc 3, the rotating shaft 6. The upper rotating disc 1, the middle rotating disc 2, the lower rotating disc 3 are all provided with drum (11, 21, 31), and the three rotating discs are fixedly connected through the drum. The upper rotating disc 1 and the middle rotating disc 2 are left with an air inlet gap 9 between the outer circumferential surfaces. The rotating shaft 6 passes through the center holes of the upper rotating disc 1, the middle rotating disc 2 and the lower rotating disc 3, the inner diameters of the upper rotating disc 1 and the middle rotating disc 2 are equal, and the upper rotating disc 1, the middle rotating disc 2 and the rotating shaft 6 are fixedly connected, and the lower rotating disc 3 and the rotating shaft 6 are left with an air outlet gap 10.

[0025] The side wall of the upper rotating disc 1 close to the middle rotating disc 2, the side wall of the middle rotating disc 2 close to the upper rotating disc 1, the upper surface of the upper rotating disc drum 11 and the upper surface of the middle rotating disc drum 21 surround to form a high disc cavity 8, and the cross section of the high disc cavity 8 can be rectangular, circular or any polygonal shape. The side wall of the middle rotating disc 2 close to the lower rotating disc 3, the side wall of the lower rotating disc 3 close to the middle rotating disc 2, the lower surface of the middle rotating disc drum 21 and the lower surface of the lower rotating disc drum 31 surround to form a low vortex reducer disc cavity 7.

[0026] As shown in the figure, Figure 2 A plurality of vortex reduction holes 5 are opened on the middle rotating disc 2, which are distributed equidistantly along the circumference, and eight vortex reduction holes are opened in the embodiment. The cross section of the vortex reduction hole 5 is circular, elliptical, square or any polygonal shape. The axis of the vortex reduction hole 5 and the axis of the middle rotating disc 2 form a preset angle, which is 20-70°, so as to ensure the communication between the high disc cavity and the low vortex reducer disc cavity. The inlet rotating radius r i of the vortex reduction hole 5 is less than the outer radius r b of the middle rotating disc 2, and the outlet rotating radius r o of the vortex reduction hole 5 is greater than the inner radius r a of the middle rotating disc 2. The edges of the inlet and outlet of the vortex reduction hole 5 are chamfered or rounded to further reduce the loss of airflow when entering the hole.

[0027] As shown in the figures, Figure 3 and Figure 4 The low vortex reducer disc cavity 7 is also provided with an Archimedes spiral type guide plate 4, the number of the vortex reduction holes and the Archimedes spiral type guide plates is the same, and the Archimedes spiral type guide plate is installed between two vortex reduction holes. The Archimedes spiral type guide plate 4 includes a main plate 41 and a bottom plate 42 perpendicular to each other, the bottom plate 42 is provided with a screw hole, and the main plate 41 and the bottom plate 42 can be connected by welding or integrally formed. The profile line of one reference Archimedes spiral type guide plate (4) satisfies the Archimedes spiral line relationship, that is, r=aΘ, 0<Θ<π / 2, 2r d / π<a<10rd The other guide plate profile lines are obtained from the array of the reference guide plate profile lines. The lower rotating disc 3 is provided with a fixed groove on the side wall close to the middle rotating disc 2, and the bottom plate 42 is installed in the fixed groove through bolts. The main plate 41 is perpendicular to the disc surface of the lower rotating disc 3. The height of the main plate is h, and the radial length is l, wherein the highest point of the main plate 41 in the radial direction of the rotating disc, i.e. the highest point in the length l direction, is higher than the outlet of the vortex reduction hole 5 to guide the airflow out of the air gap 10. The Archimedes spiral type guide plate can effectively reduce the relative tangential velocity of the air, so that the airflow flows more smoothly through the air gap 10, and the low radius free vortex loss of the air is reduced.

[0028] The air inlet gap 9, the high disc cavity 8, the vortex reduction hole 5, the low vortex reducer disc cavity 7 and the air outlet gap 10 are communicated to form an airflow passage. The airflow enters from the air inlet gap 9, then passes through the high disc cavity 8, the vortex reduction hole 5 and the low vortex reducer disc cavity 7 in sequence, and flows out from the air outlet gap 10 after being guided by the Archimedes spiral type guide plate 4. The present application effectively reduces the relative tangential velocity of the air by reasonably setting the vortex reduction hole and cooperating with the Archimedes spiral type guide plate, so that the airflow flows out more smoothly, the low radius free vortex loss of the air is reduced, and the air system drag reduction performance is improved.

Claims

1. A composite Archimedean spiral drag reduction device for improving the bleed air performance of a heavy-duty gas turbine, characterized in that: The invention comprises an upper rotating disk (1), an intermediate rotating disk (2), and a lower rotating disk (3), wherein the upper rotating disk (1), the intermediate rotating disk (2), and the lower rotating disk (3) are all provided with drums, and the three rotating disks are fixedly connected via the drums; an air inlet slit (9) is left between the outer circumferences of the upper rotating disk (1) and the intermediate rotating disk (2), and an air outlet slit (10) is provided at the bottom of the lower rotating disk (3); The side wall of the upper rotating disk (1) close to the intermediate rotating disk (2), the side wall of the intermediate rotating disk (2) close to the upper rotating disk (1), the upper surface of the drum of the upper rotating disk (1), and the upper surface of the drum of the intermediate rotating disk (2) surround to form a high-position disk cavity (8); the side wall of the intermediate rotating disk (2) close to the lower rotating disk (3), the side wall of the lower rotating disk (3) close to the intermediate rotating disk (2), the lower surface of the drum of the intermediate rotating disk (2), and the lower surface of the drum of the lower rotating disk (3) surround to form a low-position vortex reducer disk cavity (7); an Archimedean spiral guide plate (4) is further provided in the low-position vortex reducer disk cavity (7) to guide the airflow flowing out of the vortex reduction hole (5) to the air outlet slit (10); A vortex reduction hole (5) is provided on the drum of the intermediate rotating disk (2); an air inlet slit (9), a high-position disk cavity (8), a vortex reduction hole (5), a low-position vortex reducer disk cavity (7), and an air outlet slit (10) are connected to form an air flow passage; the axis of the vortex reduction hole (5) and the axis of the intermediate rotating disk (2) form a preset angle to ensure the communication between the high-position disk cavity (8) and the low-position vortex reducer disk cavity (7).

2. The drag reduction device according to claim 1, characterized in that: The preset included angle of the vortex reducing hole (5) is 20-70°.

3. The drag reduction device according to claim 1, wherein: The inlet rotation radius r of the vortex reduction hole (5) i Smaller than the outer radius r of the intermediate rotating disk (2) b .

4. The drag reduction device according to claim 3, characterized in that: The outlet rotation radius r of the vortex reducing hole (5) o Greater than the inner radius r of the intermediate rotating disk (2) a .

5. The drag reduction device according to claim 1, wherein: The Archimedean spiral guide plate (4) comprises a main plate (41) and a bottom plate (42) perpendicular to each other, wherein the contour line of one of the reference Archimedean spiral guide plates (4) satisfies the Archimedean spiral relationship, i.e., r=aΘ, 0<Θ<π / 2, 2r d / π<a<10r d , the other guide plate contour lines are obtained from the reference guide plate contour line array; the bottom plate (42) is fixed on the lower rotating disk (3), and the main plate (41) is perpendicular to the disk surface of the lower rotating disk (3).

6. The drag reduction device according to claim 5, characterized in that: The highest point of the main plate (41) in the radial direction of the rotating disk is higher than the outlet of the vortex reducing hole (5) so as to guide the airflow flowing out of the vortex reducing hole (5) to the air outlet slit (10).

7. The drag reduction device according to claim 5, characterized in that: A fixing groove is provided on the side wall of the lower rotating disk (3) close to the intermediate rotating disk (2), and the bottom plate (42) is installed in the fixing groove by means of bolts.

8. The drag reduction device according to claim 1, wherein: The invention also includes a rotating shaft (6), which passes through the center holes of the upper rotating disk (1), the intermediate rotating disk (2), and the lower rotating disk (3). The inner diameters of the upper rotating disk (1) and the intermediate rotating disk (2) are equal, and the upper rotating disk (1), the intermediate rotating disk (2) and the rotating shaft (6) are fixedly connected. An air outlet gap (10) is left between the lower rotating disk (3) and the rotating shaft (6).

9. The drag reduction device according to claim 1, wherein: The cross section of the high-position disc cavity (8) is rectangular, circular or any other polygonal shape.

10. The drag reduction device according to claim 1, wherein: The cross section of the vortex reducing hole (5) is any one of circular, elliptical, square and polygonal.

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