A high-efficiency cooling structure of a gas turbine guide vane under strong rotational flow and a turbine blade

Abstract

The application discloses a high-efficiency cooling structure of a gas turbine guide vane under strong rotational flow and a turbine blade, and relates to the technical field of turbine blades. The high-efficiency cooling structure of the guide vane changes the flow structure and cooling characteristics of the surface of the guide vane under the action of strong rotational flow, has high utilization rate of cooling air, makes the temperature of the blade more uniform, and guarantees the structural strength of the guide vane after the arrangement of the film holes, thereby guaranteeing the high-efficiency and reliable operation of the guide vane.

Description

Technical Field

[0001] This invention relates to the field of gas turbine blade cooling technology, specifically to a high-efficiency cooling structure for gas turbine guide vanes and turbine blades under strong swirling flow. Background Technology

[0002] Gas turbines are playing an increasingly important role in energy sectors such as propulsion, electricity, and petroleum. As a core component of gas turbine systems, improving the gas-thermal performance of the turbine is crucial for enhancing the overall performance of the gas turbine. High-performance gas turbines have consistently been developed with the goals of high thrust, high efficiency, low weight, and small size in mind. To ensure the normal operation and service life of hot-end components such as turbine blades, researchers have continuously developed various cooling and protection technologies over the past few decades to further improve the temperature resistance limits of these components. Among various cooling methods, film cooling plays a vital role. Film cooling involves drilling holes in the turbine blades and injecting cold gas into the mains flow through these holes. Under the pressure of the mains flow, this cold gas adheres to the turbine wall, forming a low-temperature film protective layer. This film isolates the high-temperature gas from direct contact with the wall and carries away some of the radiant heat from the gas, thus providing excellent thermal protection.

[0003] Lean fuel premixed combustion technology is widely used in modern aero engines to respond to increasingly stringent pollutant emission policies. Advanced fuel atomizing nozzles used in conjunction with this technology generate a strong swirling flow field inside the combustion chamber to maintain a stable combustion flame. However, as engine sizes become more compact, the distance between the combustion chamber outlet and the turbine inlet is gradually shortening. The swirling flow cannot decay within this short distance, resulting in strong eddies extending into the turbine. Combined with the inherent uneven temperature distribution within the combustion chamber, this coupling effect further reduces the film cooling coverage of the turbine's first-stage stator blades, thus impacting turbine blade life.

[0004] A reasonable cooling structure layout for gas turbine guide vanes can effectively improve the temperature non-uniformity caused by strong swirling flow and increase the efficiency of film cooling on the blade surface. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a high-efficiency cooling structure for gas turbine guide vanes and turbine blades under strong swirling flow. The reasonable arrangement of the cooling structure on the gas turbine guide vanes effectively reduces the impact of strong swirling flow on the gas film coverage on the blade surface, and improves the cooling efficiency of the gas film on the blade surface while improving temperature non-uniformity.

[0006] This invention is achieved through the following technical solution:

[0007] A high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow includes pressure hole groups, leading edge hole groups, and suction hole groups arranged on the pressure side, leading edge, and suction side of the blade. Each hole group consists of multiple film cooling holes, which are spaced apart along the height direction of the blade. The inlet of each film cooling hole is connected to the cooling chamber of the blade.

[0008] Each air film hole in the pressure hole group is a converging slit-shaped hole, each air film hole in the leading edge hole group is a teardrop-shaped counter-flush hole, and each air film hole in the suction hole group is a round hole.

[0009] Preferably, the leading edge hole group consists of two groups, which are arranged in parallel and spaced apart on the curved surface of the leading edge of the blade.

[0010] Preferably, the pressure face group is arranged at the midline position of the blade pressure difference.

[0011] Preferably, the inlet of the converging slit-shaped orifice is a circular orifice, which gradually converges to a groove shape along the axial direction from the inlet to the outlet and then diverges outward. The axial direction of the converging slit-shaped orifice forms an incident angle with the flow direction of the mainstream gas, with an incident angle of 15°-75°.

[0012] Preferably, the teardrop-shaped counter-punching holes expand along the blade height, and the axial direction of the teardrop-shaped counter-punching holes forms an incident angle with the blade height, with the incident angle being 30°-60°. Multiple teardrop-shaped counter-punching holes are symmetrically arranged along the middle of the blade height.

[0013] Preferably, the axial direction of the cylindrical hole is at an incident angle to the flow direction of the mainstream gas, and the incident angle is 15°-75°.

[0014] Preferably, the distance between two adjacent converging slit-shaped holes is 2-4 times the diameter of the air film hole inlet; the distance between two adjacent teardrop-shaped flushing holes is 2-5 times the diameter of the air film hole inlet; and the distance between two adjacent converging slit-shaped holes is 2-4 times the diameter of the air film hole inlet.

[0015] Preferably, the inlet diameter of the air film pore is 0.2-1 mm.

[0016] A turbine blade includes a blade body, with a blade tenon and a hub respectively provided at the blade tip and blade root, characterized in that the cooling structure is provided on the blade body.

[0017] A gas turbine, including the turbine blades.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] This invention provides a high-efficiency cooling structure for gas turbine guide vanes under strong swirling conditions. The turbine blade's pressure side, leading edge, and suction side are respectively equipped with pressure hole groups, leading edge hole groups, and suction hole groups to form a high-efficiency cooling structure. The pressure hole groups employ multiple converging slit-shaped film cooling holes, the leading edge hole groups employ multiple opposing teardrop-shaped film cooling holes, and the pressure hole groups employ multiple cylindrical film cooling holes. This high-efficiency cooling structure suppresses the influence of swirling flow, reduces surface temperature non-uniformity, and improves film cooling coverage. Simultaneously, the spanwise expansion of the exit of the converging slit-shaped holes provides a certain spanwise velocity component to the cooling jet, enabling the cold gas jet to form a uniform cooling film on the pressure surface, isolating the high-temperature combustion gas from the swirling flow, and the larger exit momentum reduces cold gas dissipation. The opposing teardrop-shaped holes significantly reduce the exit velocity and provide a certain spanwise velocity component, improving film adhesion while reducing the momentum of the cold gas opposing the swirling flow, thereby reducing the cold gas dissipation rate. The cylindrical holes on the suction side allow the cooling jet to form a uniformly covered gas film on the suction surface, reducing the temperature non-uniformity caused by the swirling flow. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the high-efficiency cooling structure for the gas turbine guide vanes of the present invention;

[0021] Figure 2 This is a front view of the high-efficiency cooling structure for the gas turbine guide vanes of the present invention;

[0022] Figure 3 This is a side view of the high-efficiency cooling structure for the gas turbine guide vanes of the present invention;

[0023] Figure 4 This is a rear view of the efficient cooling structure for the gas turbine guide vanes of the present invention.

[0024] In the figure: 1-blade, 2-pressure hole row, 3-leading edge hole row, 4-blade tip, 5-suction hole row, 6-pressure side, 7-blade leading edge, 8-converging slit-shaped hole, 9-opposing teardrop-shaped hole, 10-cylindrical hole. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings. These descriptions are intended to explain the invention and not to limit it.

[0026] See Figure 1-4 A high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow includes a pressure hole group 2, a leading edge hole group 3, and a suction hole group 10. Each hole group consists of multiple film pores, and the film pore structures of each hole group are different.

[0027] The pressure hole group 2 is arranged at the middle chord position on the pressure side of the blade, the leading edge hole group 3 is arranged at the leading edge of the blade, and the suction hole group 10 is arranged at the leading edge position on the suction side of the blade. The multiple air film holes of each hole group are arranged at intervals from the blade tip to the blade root and are connected to the cooling cavity of the blade.

[0028] The blade has a double-walled structure with a complex cooling cavity formed between the two walls.

[0029] Each air film orifice in the pressure surface group 2 is a converging slit-shaped orifice, used to generate a spanwise velocity component in the cooling jet, thereby forming a uniform cooling air film on the pressure surface. The outlet of the converging slit-shaped orifice is located on the surface of the blade, and the inlet of the converging slit-shaped orifice is a circular hole that gradually converges to a groove shape and diverges spanwise from the inlet to the outlet along the axial direction.

[0030] The converging slits of the pressure face group 2 are spaced apart along the blade height direction. The distance between two adjacent converging slits is L1, ranging from 2D to 4D. The axial direction of the converging slits forms an incident angle α1 with the flow direction, ranging from 15° to 75°.

[0031] Each film cooling hole in the leading edge hole group 3 is a teardrop-shaped opposing hole. The expansion of the teardrop-shaped hole outlet reduces the velocity of the cooling jet outlet and gives the cooling jet a certain spanwise velocity component, improving the film cooling adhesion. The opposing arrangement of the teardrop-shaped holes allows for counter-current jetting of cold air, resulting in more concentrated film cooling coverage in the middle area and reducing the influence of swirling flow, thereby improving film cooling efficiency. The outlet of the teardrop-shaped opposing hole is an open structure, and the inlet is connected to the cooling chamber of the blade.

[0032] Multiple teardrop-shaped counter-jet holes in leading edge hole group 3 are symmetrically and obliquely arranged along the center of the blade height. The axial direction of the teardrop-shaped counter-jet holes forms an incident angle α2 with the blade height, ranging from 30° to 60°. This divides the multiple teardrop-shaped counter-jet holes into two groups along the blade height: the teardrop-shaped counter-jet holes above the blade height line are inclined downwards, while those below the blade height line are inclined upwards. The axial direction of the teardrop-shaped counter-jet holes forms an incident angle α2 with the blade height, ranging from 30° to 60°.

[0033] The teardrop-shaped counter-punching holes expand along the blade height with an expansion angle of β1. The spacing between two adjacent teardrop-shaped counter-punching holes is L2, ranging from 2D to 5D. The number of membrane pores is n2.

[0034] The leading edge hole group 3 consists of two groups, which are arranged in parallel and spaced apart on the curved surface of the leading edge of the blade.

[0035] Each film cooling hole in the suction face assembly 10 is a cylindrical hole, used to form a film cooling jet on the suction surface, thus reducing the temperature non-uniformity caused by swirling flow. The suction face assembly 10 is located on the side of the suction surface near the leading edge, with a spacing of L1 between two adjacent film cooling holes, ranging from 2D to 4D, and the number of film cooling holes is n1; the axial direction of the cylindrical holes forms an incident angle α3 with the flow direction, ranging from 15° to 75°.

[0036] The inlet diameter D of the air film pore ranges from 0.2 to 1 mm, and is preferably 0.5 mm.

[0037] The aforementioned high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow effectively suppresses the influence of strong swirling flow on the gas turbine guide vanes and improves temperature non-uniformity. Pressure hole group 2, leading edge hole group 3, and suction hole group 10 are respectively arranged on the pressure side, leading edge, and suction side of the blade. Each film cooling hole in pressure hole group 2 adopts a converging slit shape, which effectively suppresses the lateral flow influence of the swirling flow and improves the spanwise film cooling effect. The opposing teardrop-shaped holes in leading edge hole group 3 alter the deflection effect caused by the strong swirling flow impact on the blade leading edge. The cylindrical holes in suction hole group 10 effectively suppress the lateral flow of the swirling flow on the suction side and reduce temperature non-uniformity on the blade surface. This structure improves the overall cooling performance of the gas turbine under the influence of strong swirling flow, effectively improves the temperature non-uniformity caused by the strong swirling flow, and simultaneously increases the film cooling efficiency on the blade surface.

[0038] Example 1

[0039] A high-efficiency cooling structure for a gas turbine guide vane under strong swirling flow is provided, wherein pressure hole group 2, leading edge hole group 3, and suction hole group 10 are respectively arranged on the pressure side, leading edge, and suction side of the blade. Pressure hole group 2, leading edge hole group 3, and suction hole group 10 are all composed of multiple film vents. The multiple film vents are spaced apart along the height direction of the blade. The inlet of the film vent is connected to the cooling chamber of the blade and the outlet is located on the surface of the blade.

[0040] Each film pore in pressure hole group 2 is a converging slit-shaped pore 8, with the axis of the converging slit-shaped pore forming an incident angle of α1 with the flow direction, which is 30°; the outlet slit length and slit width of the converging slit-shaped pore 8 are 3D and 0.5D, respectively. The number of film pores in pressure hole group 2 is 19, and the pore spacing is 4D.

[0041] Each film-forming air vent in leading edge vent group 3 is a teardrop-shaped opposing air vent. Multiple teardrop-shaped opposing air vents are divided into two groups along the center of the blade height. The two groups of teardrop-shaped opposing air vents are symmetrically arranged. The outlet of the first group of teardrop-shaped opposing air vents is inclined towards the blade root, and the outlet of the second group is inclined towards the blade tip. That is, the two groups of teardrop-shaped opposing air vents are arranged in a figure-eight shape along the blade height. The airflow generated by the two groups of teardrop-shaped opposing air vents opposes each other. The axis of the teardrop-shaped opposing air vents forms an incident angle α2 with the blade height, which is 45°. The outlet of the teardrop-shaped air vents expands by 15° along the blade height. Leading edge vent group 3 has 20 film-forming air vents with a vent spacing of 3D.

[0042] Each air film hole in the suction hole group 10 is a cylindrical hole, and the axis of the cylindrical hole is at an incident angle of α3 with the flow direction, which is 50°. The number of air films in the suction hole group 10 is 10, and the hole spacing is 3D, where D is the inlet diameter of the air film hole, which is 0.5 mm.

[0043] This cooling structure, by arranging film cooling holes of different shapes at different locations on the blade surface, suppresses the influence of swirling flow, reduces temperature non-uniformity on the blade surface, and improves the film cooling coverage effect. For the pressure hole group, the spanwise expansion of the exit of the converging slit-shaped holes provides a certain spanwise velocity component for the cooling jet, enabling the cold gas jet to form a uniform cooling film on the pressure surface, isolating the high-temperature combustion gas of the swirling flow, and the larger exit momentum makes it less likely to dissipate with the mainstream. For the leading edge hole group 3, since the jet direction of the leading edge opposing holes is consistent with the tangential velocity direction of the swirling flow, the swirling flow has a stronger entrainment and carrying effect on the film cooling at this hole group compared to other areas of the film cooling. The teardrop holes significantly reduce the exit velocity and provide a certain spanwise velocity component, improving the film cooling adhesion. The upper and lower opposing arrangement of the teardrop holes allows for opposing jetting of cold gas, resulting in a more concentrated film cooling coverage in the middle area, reducing the influence of swirling flow, and thus improving the film cooling efficiency. The cylindrical holes of the suction hole group 10 enable the cooling jet to form a film on the suction surface, reducing the temperature non-uniformity caused by swirling flow.

[0044] Example 2

[0045] The present invention also provides a turbine blade, including a blade body, a blade tenon at the top of the blade body, and a hub at the blade root, wherein the cooling structure is arranged on the blade body.

[0046] Example 3

[0047] A gas turbine, wherein the turbine blades are provided with the aforementioned cooling structure.

[0048] The turbine blade forms a highly efficient cooling structure by arranging pressure hole group 2, leading edge hole row 3, and suction hole group 10 on its blade body. This cooling structure arranges a reasonably structured film cooling hole at different positions on the blade body, which increases the spanwise momentum of the film cooling hole outlet, has a good film cooling effect between the hole rows, and reduces the flow momentum at the outlet to reduce the mixing of cold air with the mainstream. The film cooling coverage is wider, thus improving the cooling efficiency. On the other hand, this cooling structure suppresses the influence of swirling flow, reduces the temperature non-uniformity of the blade surface, and forms a uniform cooling film on the blade surface with the cold air jet, isolating the high-temperature combustion gas of the swirling flow, improving the film cooling coverage effect, and thus improving the cooling effect of the turbine blade.

[0049] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow, characterized in that, It includes pressure hole group (2), leading edge hole group (3) and suction hole group (10) arranged on the pressure side, leading edge and suction side of the blade. Each hole group is composed of multiple air film holes. Each air film hole is arranged at intervals along the height direction of the blade. The inlet of each air film hole is connected to the cooling chamber of the blade. Each air film hole of the pressure hole group (2) is a converging slit-shaped hole, each air film hole of the leading edge hole group (3) is a teardrop-shaped counter-punching hole, and each air film hole of the suction hole group (10) is a cylindrical hole. The inlet of the converging slit-shaped orifice is a circular hole, which gradually converges to a groove shape along the axial direction from the inlet to the outlet and then diverges outward. The axial direction of the converging slit-shaped orifice is at an incident angle to the flow direction of the mainstream gas, with an incident angle of 15°-75°. The teardrop-shaped punch expands along the blade height, and the axial direction of the teardrop-shaped punch forms an incident angle with the blade height, with the incident angle being 30°-60°. Multiple teardrop-shaped counter-punch holes are symmetrically arranged along the middle of the blade height; The axial direction of the cylindrical hole is at an incident angle to the flow direction of the mainstream gas, with an incident angle of 15°-75°.

2. The efficient cooling structure for gas turbine guide vanes under strong swirling flow as described in claim 1, characterized in that, The leading edge hole group (3) consists of two groups, which are arranged in parallel and spaced apart on the curved surface of the leading edge of the blade.

3. The high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow as described in claim 1, characterized in that, The pressure face group (2) is arranged at the midline position of the pressure difference in the blade.

4. The high-efficiency cooling structure for gas turbine guide vanes under strong swirling flow as described in claim 1, characterized in that, The spacing between two adjacent converging slit-shaped holes is 2-4 times the inlet diameter of the film gas vent; the spacing between two adjacent teardrop-shaped counter-flush holes is 2-5 times the inlet diameter of the film gas vent; and the spacing between two adjacent converging slit-shaped holes is 2-4 times the inlet diameter of the film gas vent.

5. A turbine blade, comprising a blade body, wherein a blade tenon and a hub are respectively provided at the blade tip and blade root, characterized in that, The blade is provided with a cooling structure as described in any one of claims 1-4.

6. A gas turbine, characterized in that, Includes the turbine blade as described in claim 5.

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