A flow guiding device for the tenon of a turbine rotor blade

Abstract

This invention pertains to the field of aero-engine technology, proposing a flow guiding device for a turbine rotor blade tenon. The device includes a blade tenon and a high-pressure return cavity connected to the blade tenon. Multiple channels are formed on one plane of the blade tenon, each channel communicating with the high-pressure return cavity. A flow guiding platform is provided on one plane of the blade tenon, adjacent to a corresponding channel. An air intake surface and a flow guiding surface are respectively provided on two adjacent sides of the flow guiding platform. The air intake surface is close to the air intake of the blade tenon, and the flow guiding surface is located above the corresponding channel. The flow guiding platform reduces drag and vortices, increasing the flow rate of cold air into the high-pressure return cavity through the corresponding channel, accelerating the flow velocity, and preventing severe impact on the blade tip. A large vortex system is formed at the channel location far from the flow guiding platform, reducing the cold air velocity at the channel inlet, achieving a reasonable airflow distribution across channels, and preventing excessive cold air consumption from affecting engine performance.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, and specifically relates to a flow guiding device for the tenon of a turbine rotor blade. Background Technology

[0002] In aero-engines, turbine blade cooling typically combines film cooling and internal channel cooling. Film cooling works by circulating cooling air through slots or cooling holes machined into the turbine blade, uniformly covering the blade surface and creating an air thermal resistance layer that hinders direct heat transfer between the high-temperature combustion gases and the blade surface. Internal channel cooling involves the cooling airflow flowing within cooling channels inside the blade, achieving convective heat transfer and removing heat. Furthermore, to enhance heat transfer, turbulence-enhancing structural elements and impingement holes are often added.

[0003] However, the aforementioned turbine rotor blade cooling structure consists of leading edge impact, blade film cooling, and ribbed turbulence. When the turbine rotor blade is directly impacted by high-temperature and high-pressure combustion gases, edge ablation is likely to occur at the leading edge of the blade and near the leading edge of the blade basin. The heat exchange capacity of the leading edge air supply chamber and the ribbed channel in the middle of the blade body has limited potential for improvement. Furthermore, in order to provide effective thermal protection for the leading edge of the blade and near the leading edge of the blade basin, a large amount of cold air and a greater cold air pressure loss are required to improve the internal cavity heat transfer coefficient. However, excessive use of cold air will seriously affect the engine performance. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a flow guiding device for a turbine rotor blade tenon, comprising: a blade tenon and a high-pressure return cavity communicating with the blade tenon; multiple channels are formed on a plane of the blade tenon, each channel communicating with the high-pressure return cavity; a flow guiding platform is provided on a plane of the blade tenon, the flow guiding platform being close to the corresponding channel; an air inlet surface and a flow guiding surface are respectively provided on two adjacent sides of the flow guiding platform, the air inlet surface being close to the air inlet of the blade tenon, and the flow guiding surface being located above the corresponding channel.

[0005] Optionally, the air intake surface is projected onto the reference point in the X direction to form an angle α, which is between 8° and 15°, and the reference point is the center point of the blade.

[0006] Optionally, the axial direction of the guide surface forms an angle β with the Y direction of the reference point, and the angle β is 35° to 50°.

[0007] Optionally, the distance between the dividing line on the guide surface and the reference point of the blade tenon is a, and the distance a is between 1.5 mm and 2 mm.

[0008] Optionally, the distance between the end of the air intake surface and one side of the blade tenon is c, and the distance c is between 1.5 mm and 2.5 mm.

[0009] Optionally, the height of the flow guide is d, which is between 2 mm and 3 mm.

[0010] Optionally, there are three channels, each connected to the high-pressure return chamber.

[0011] Optionally, the high-pressure reflux chamber includes a first chamber, a second chamber, a third chamber, and a fourth chamber. Two adjacent channels are respectively connected to the second chamber, and the other channel is connected to the third chamber. The first chamber and the second chamber are connected, and the third chamber and the fourth chamber are connected.

[0012] Optionally, a plurality of air film holes are provided on one side wall of the first cavity, and a plurality of vent holes are provided on the other side wall of the first cavity to connect the first cavity and the second cavity.

[0013] Optionally, the second cavity has an L-shaped structure and multiple exhaust holes at its end, and the outlet end of the fourth cavity has multiple slits.

[0014] Compared with the prior art, the flow guiding device of the turbine rotor blade tenon of the present invention has the following advantages: by providing a flow guiding platform and an air intake surface on one plane of the blade tenon, the cooling airflow can be guided into the corresponding channel. In addition, the flow guiding surface on the flow guiding platform can play a role in stabilizing the flow, thereby reducing the vortex system generated near the corresponding channel and increasing the flow rate of cold air flowing into the high-pressure return chamber in this channel. At the same time, a larger vortex system is formed at the channel position at the end away from the flow guiding platform, reducing the cold air velocity at the channel inlet and the flow rate of cold air entering this channel. This affects the distribution of cold air flow in multiple channels, making the distribution of cold air more reasonable and avoiding the problem of excessive cold air consumption seriously affecting the engine performance.

[0015] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1A schematic diagram of the flow guiding device for the turbine rotor blade tenon in an embodiment of the present invention is shown;

[0018] Figure 2 A schematic diagram of the airflow direction inside the flow guiding device of the turbine rotor blade tenon in an embodiment of the present invention is shown;

[0019] Figure 3 A schematic diagram of the inner cavity of the flow guiding device for the turbine rotor blade tenon in an embodiment of the present invention is shown;

[0020] Figure 4 This diagram illustrates the reference point of the flow guiding device and the XY coordinates of the blade tenon in an embodiment of the present invention.

[0021] Figure 5 This diagram illustrates the reference point of the flow guiding device and the ZY coordinates of the blade tenon in an embodiment of the present invention.

[0022] Figure 6 Another schematic diagram of the flow guiding device guide platform for the turbine rotor blade tenon in an embodiment of the present invention is shown.

[0023] Figure 7 A schematic diagram of the inlet flow field of the flow guiding device for the turbine rotor blade tenon in an embodiment of the present invention is shown.

[0024] In the diagram, 1 is the blade tenon; 11 is the channel; 2 is the high-pressure return chamber; 21 is the first chamber; 22 is the second chamber; 23 is the third chamber; 24 is the fourth chamber; 211 is the film vent; 212 is the vent hole; 221 is the exhaust hole; 241 is the slit; 3 is the guide platform; 31 is the air inlet surface; 32 is the guide surface; 33 is the back air surface; 34 is the dividing line; 311 is the first air inlet rounded corner surface; 312 is the first air inlet inclined surface; 331 is the second air inlet rounded corner surface; 332 is the second air inlet inclined surface. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figure 2 As shown, the present invention provides a flow guiding device for a turbine rotor blade tenon, comprising: a blade tenon 1 and a high-pressure return cavity 2 communicating with the blade tenon 1. Multiple channels 11 are formed on a plane of the blade tenon 1, each channel 11 communicating with the high-pressure return cavity 2, as shown below. Figure 1 As shown, a guide platform 3 is provided on one plane of the blade tenon 1, close to the corresponding channel 11. An air intake surface 31 and a guide surface 32 are respectively provided on two adjacent sides of the guide platform 3. The air intake surface 31 is close to the air intake of the blade tenon 1, and the guide surface 32 is located above the corresponding channel 11. The guide platform 3 reduces drag and vortices, i.e., it reduces the vortex system on the corresponding channel 11, increasing the cold air flow rate in the corresponding channel 11. This increases the flow rate and velocity of the cold air flowing into the high-pressure return chamber 2, thus rationally distributing the cold air flow and avoiding severe impact on the blade tip, implementing precise thermal protection. A larger vortex system is formed at the location of the channel 11 away from the guide platform 3, reducing the cold air velocity at the inlet of the channel 11 and increasing the temperature in the low-temperature zone of the blade midsection. This achieves a rational distribution of airflow in each channel 11, preventing excessive cold air usage from severely affecting engine performance. Optionally, the guide platform 3 has an approximate bird beak shape. The bird beak shape facilitates the guidance of airflow direction, reduces the maximum temperature and average temperature of the entire blade, increases the temperature of the low-temperature zone in the middle section of the blade, reduces the blade temperature gradient, and improves the blade's service life.

[0027] like Figure 4 As shown, in one embodiment, the air intake surface 31 is projected onto the reference point X direction to form an angle α, which is between 8° and 15°. The reference point is the center point of the blade. Specifically, α is 10°. By using a suitable α angle range, the air intake surface 31 can most effectively guide the gas into the corresponding channel 11, thereby reasonably increasing the amount of gas entering the corresponding channel 11 and thus rationally distributing the gas flowing into each channel 11. Figure 6 As shown, optionally, the intake surface 31 is rounded to form a first intake rounded surface 311 and a first intake ramp 312. The radius of the first intake rounded surface 311 ranges from 0.5 to 1.2 mm, specifically, the radius is 1 mm. The other end face of the back air surface 33, away from the guide platform 3, is also rounded to form a second intake rounded surface 331 and a second intake ramp 332. The radius of this rounded surface ranges from 0.5 to 1.2 mm, specifically, the radius is 1 mm.

[0028] In one embodiment, the axial direction of the guide surface 32 forms an angle β with the Y direction of the reference point, where β is 35° to 50°. Specifically, β is 40°. This suitable angle β allows the guide surface 32 to more stably guide the gas into the corresponding channel 11. The interaction between the guide surface 32 and the intake surface 31 reduces the vortex system generated at the channel 11 corresponding to the guide platform 3, increasing the air intake at that channel 11. Conversely, the vortex system generated at channels 11 farther from the guide platform 3 increases, reducing the air intake at those channels 11, thus rationally distributing the air intake across each channel 11. Figure 4 As shown, optionally, the outer radius R of the flow guide 3 is consistent with the radius of the arc at the bottom of the tenon, and the outer radius R of the flow guide 3 is 2.7 mm.

[0029] like Figure 1 As shown, in one embodiment, the center distance between the dividing line 34 on the guide surface 32 and the reference point of the blade tenon 1 is a, as... Figure 4 As shown, the distance 'a' is between 1.5 mm and 2 mm. Specifically, 'a' is 2 mm. With a suitable 'a', the guide surface 32 can more stably guide the gas into the corresponding channel 11, and effectively guide the gas flow rate to be reasonably distributed into the corresponding channel 11. It should be noted that the dividing line 34 separates the guide surface 32 from the other end adjacent to the guide surface 32. This end face can block part of the airflow, prevent airflow loss, and thus form a vortex system.

[0030] In one embodiment, the distance c between the end of the air inlet surface 31 and one side edge of the blade is between 1.5 mm and 2.5 mm. Specifically, c is 2 mm. By using an appropriate c, the gas flow rate entering the corresponding channel 11 can be guided and distributed more efficiently and rationally. This reduces the maximum temperature and average temperature of the entire blade, increases the temperature in the low-temperature zone of the blade's middle section, reduces the blade temperature gradient, and improves the blade's service life.

[0031] like Figure 2 As shown, in one embodiment, the height of the guide platform 3 is d, which is between 2 mm and 3 mm. Optionally, d is 2.4 mm. By using an appropriate height distance d, the size of the vortex system generated at the channel 11 corresponding to the guide surface 32 and at the channel 11 far away from the guide surface 32 can be affected, thereby affecting the intake flow of each channel 11. This ensures a reasonable distribution of the intake flow of each channel 11 and avoids the problem of excessive cold air consumption seriously affecting the engine performance.

[0032] like Figure 5 As shown, in one embodiment, there are three channels 11, each connected to the high-pressure return chamber 2. It should be noted that the three channels 11 are independent of each other, and the guide platform 3 is located near two of the channels 11. This reduces the vortex system near these two channels 11, increasing the gas flow rate within the channels 11. Conversely, the vortex system in the channel 11 furthest from the guide platform 3 increases, reducing the gas flow rate in that channel 11. This achieves a reasonable distribution of gas flow rate across each channel 11.

[0033] like Figure 2As shown, in one embodiment, the high-pressure return chamber 2 includes a first chamber 21, a second chamber 22, a third chamber 23, and a fourth chamber 24. Two adjacent channels 11 are connected to the second chamber 22, and another channel 11 is connected to the third chamber 23. The first chamber 21 and the second chamber 22 are connected, and the third chamber 23 and the fourth chamber 24 are connected. It should be noted that a large vortex is easily formed in the channel 11 where there is no guide platform 3. The cold air velocity at this channel 11 is reduced, and the amount of gas entering the first chamber 21 and the second chamber 22 is reduced. However, there is no vortex system in the channel 11 far from the air inlet, and the flow velocity is relatively fast. More cold air enters the third chamber 23 and the fourth chamber 24, resulting in a relatively small amount of cold air entering the first chamber 21 and the second chamber 22. This causes the temperature at the leading edge and blade base (near the leading edge) of the blade to be too high, while the temperature near the middle section of the blade is too low. The large temperature gradient and excessive local stress reduce the service life of the turbine rotor blades. The presence of the guide platform 3 disperses the large vortex that was originally near the guide platform 3, forming only a small vortex near the inlet of channel 11 of the guide platform 3. The cold air velocity at the inlet of channel 11 increases, increasing the flow of cold air into the blade cavity through channel 11, providing more cooling gas for the leading edge and blade basin (near the leading edge) of the blade, which are subjected to severe impact from the high temperature and high pressure gas chamber. At the same time, a large vortex is formed in channel 11 far from the air inlet, where the cold air velocity decreases and the flow of cold air entering channel 11 decreases, reducing the cooling gas supply to the middle section of the blade, and thus affecting the distribution of cold air flow in the three cold air channels 11.

[0034] In one embodiment, a plurality of film cooling holes 211 are provided on one side wall of the first cavity 21, and a plurality of vent holes 212 are provided on the other side wall of the first cavity 21 to connect the first cavity 21 and the second cavity 22. The film cooling holes 211 and vent holes provide more cooling gas to the leading edge of the blade and the blade base (near the leading edge).

[0035] In one embodiment, the second cavity 22 has an L-shaped structure and multiple exhaust holes 221 at its end, while the fourth cavity 24 has multiple slits 241 at its outlet end. The exhaust holes 221 reduce the temperature near the midsection of the blades, thus decreasing the service life of the turbine rotor blades. The slits 241 ensure that the gas flowing out of the cavities is discharged evenly, thereby improving the service life of the turbine rotor blades.

[0036] like Figure 3As shown, when the engine is running, the turbine rotor blades rotate at high speed, and a vortex system is generated at the tail of the intake passage 11 at the bottom of the blade tenon 1. Compared with rotor blades without a guide platform 3, due to the presence of the guide platform 3 in this invention, the large vortex that was originally near the guide platform 3 is dispersed, weakening the large vortex that was originally near the guide platform 3, and only forming a small vortex at that location. The energy consumption of the vortex system is reduced, and the airflow velocity near the cold air passages I and II is increased. The intake angle α is located at the intake surface 31 of the guide platform 3, which has the function of guiding the cooling airflow into passages I and II. Through the guiding effect of the guide angle β, more cooling airflow enters the blade cavity through passages I and II. At the same time, a large vortex is formed near passage III behind the guide platform 3. The airflow velocity at the inlet of passage III is reduced, and the airflow rate entering passage III is reduced, which in turn affects the airflow distribution of the three cold air passages I, II, and III. After the drag reduction and vortex reduction effect of the flow guide platform 3, the flow rate and velocity of the cold air entering channel I increase, enhancing the heat exchange capacity of the cold air inside the second cavity 22 and effectively reducing the surface temperature of the blades near the second cavity 22. The cold air inside the second cavity 22 flows radially outward, enters the first cavity 21 through the vent 212 on the partition of the first cavity 21, and performs impact cooling on the leading edge. It is then discharged through the leading edge film cooling hole 211, significantly reducing the surface temperature of the leading edge blade. The leading edge of the blade is a high-temperature zone. Through the drag reduction and vortex reduction effect of the flow guide platform 3, the flow rate and heat exchange capacity of the cooling gas in the high-temperature zone of the leading edge are improved. This provides precise thermal protection for the leading edge and blade base (near the leading edge) of the blade, which are subjected to severe impact from the high-temperature and high-pressure gas flow, helping to reduce the maximum temperature and average temperature of the entire blade, reduce the temperature gradient of the blade, and improve the service life of the blade. A flow guide platform 3 is installed at the bottom of the blade tenon 1. A large vortex is formed at the rear end face of the flow guide platform 3, i.e., at the inlet of channel III. The cold air velocity at the inlet of channel III decreases, and the flow rate of cold air entering channel III decreases. The amount of cooling gas used for the third cavity 23 and the fourth cavity 24 is reduced, and the temperature near the third cavity 23 in the middle section of the blade increases. Since the temperature in the middle section of the blade is in the low-temperature zone relative to the entire blade, the increase in temperature in the low-temperature zone helps to reduce the temperature gradient in the middle section of the blade and improve the blade's service life. The addition of the flow guide platform 3 at the bottom of the turbine rotor blade increases the flow rate and velocity of cold air entering the first cavity 21 and the second cavity 22. This provides precise thermal protection for the leading edge and blade basin (near the leading edge) of the blade, which are subjected to severe impact from the high-temperature and high-pressure gas combustion chamber. The maximum surface temperature of the turbine rotor blade is reduced by 30-55K, the average surface temperature is reduced by 15-25K, and the surface temperature in the low-temperature zone in the middle section of the blade is increased by 10-20K. This effectively reduces the surface temperature gradient of the blade and increases its service life. In addition, as Figure 7 As shown in the figure, the vortex distribution of each channel 11 is relatively uniform, which makes the air intake of each channel 11 more reasonable. Compared with the present invention, in the prior art, the vortex size is not uniform, which makes the air intake distribution of the channel 11 less uniform.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flow guiding device for the tenon of a turbine rotor blade, characterized in that, include: The blade tenon (1) and the high-pressure return cavity (2) connected to the blade tenon (1) are provided with multiple channels (11) on one plane of the blade tenon (1), and each channel (11) is connected to the high-pressure return cavity (2). A guide platform (3) is provided on one plane of the blade tenon (1), and the guide platform (3) is close to the corresponding channel (11). An air inlet surface (31) and a guide surface (32) are provided on two adjacent sides of the guide platform (3). The air inlet surface (31) is close to the air inlet of the blade tenon (1), and the guide surface (32) is located above the corresponding channel (11). The air intake surface (31) is projected onto the reference point in the X direction to form an angle α, which is between 8° and 15°. The reference point is the center point of the blade.

2. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, The axial direction of the guide surface (32) forms an angle β with the Y direction of the reference point, and the angle β is 35° to 50°.

3. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, The distance between the dividing line (34) on the guide surface (32) and the reference point of the blade tenon (1) is a, and the distance a is between 1.5 mm and 2 mm.

4. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, The distance between the end of the air intake surface (31) and one side of the blade tenon (1) is c, and the distance c is between 1.5 mm and 2.5 mm.

5. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, The height of the guide platform (3) is d, which is between 2 mm and 3 mm.

6. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, There are three channels (11), each of which is connected to the high-pressure return cavity (2).

7. The flow guiding device for the turbine rotor blade tenon according to claim 1, characterized in that, The high-pressure return chamber (2) includes a first chamber (21), a second chamber (22), a third chamber (23), and a fourth chamber (24). Two adjacent channels (11) are connected to the second chamber (22), and the other channel (11) is connected to the third chamber (23). The first chamber (21) and the second chamber (22) are connected, and the third chamber (23) and the fourth chamber (24) are connected.

8. The flow guiding device for the turbine rotor blade tenon according to claim 7, characterized in that, Multiple air film holes (211) are provided on one side wall of the first cavity (21), and multiple ventilation holes (212) are provided on the other side wall of the first cavity (21) to connect the first cavity (21) and the second cavity (22).

9. The flow guiding device for the turbine rotor blade tenon according to claim 7, characterized in that, The second cavity (22) has an L-shaped structure and multiple exhaust holes (221) at its end. The fourth cavity (24) has multiple slits (241) at its outlet end.

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