A turbine rotor blade with an internal cooling channel and a dust-proof structure

Abstract

A turbine rotor blade with an internal cooling channel and a dust-proof structure includes a swirl chamber arranged between ribbed U-shaped cooling channels inside the rotor blade, which is connected to a cooling channel with inclined ribs via a square nozzle. The top of the swirl chamber is contracted and connected to the blade top dust removal hole via a hollow spoiler column at the channel elbow. Under rotating conditions, particulate pollutants in the channel are gathered on the pressure side of the channel, and then enter the swirl chamber through the square nozzle under the guidance of the inclined ribs. The tangentially incident cold air forms a swirl in the swirl chamber. The large tangential velocity makes it difficult for particles to deposit therein, and they can only follow the cold air into the hollow channel of the spoiler column and finally flow out of the blade through the blade top dust removal hole. Under limited cold air consumption, the present invention separates the particles from the cold air and discharges them from the blade through the guiding effect of rotation and spoiler ribs and the inertia of the particles. It also optimizes the heat transfer uniformity of the blade by using swirl cooling.

Description

Technical Field

[0001] The present invention belongs to the technical field of cooling turbine blades of aircraft engines or heavy-duty gas turbines, and in particular relates to a turbine blade having an internal cooling channel and a dustproof structure. Background Art

[0002] In pursuit of ever-higher cycle efficiency, aircraft engine turbine inlet temperatures continue to rise, even exceeding the heat-resistant limits of the metal used for turbine blades. To protect the blades from being burned by the high-temperature airflow, numerous cooling structures (such as serpentine channels, impingement holes, film holes, spoiler ribs, and spoiler columns) are typically incorporated into the blades. These structures allow the cool air from the compressor to remove heat via forced convection, thereby protecting the blades.

[0003] The proper operation of aircraft engines depends not only on their structure but also on the operating environment. Long-term exposure to particulate matter, without protective measures, can penetrate the respiratory system and cause obstructive pulmonary disease (OPD). Furthermore, prolonged operation of aircraft engines in environments with high particulate matter concentrations can severely damage their aero-thermal performance.

[0004] In the high-temperature, high-pressure, and high-speed operating environment of turbine blades, particulate matter is highly susceptible to deposition on the blade surfaces. This deposition can erode the blade's thermal barrier coating, reducing or even completely rendering it ineffective. Furthermore, it increases blade surface roughness, enhancing heat transfer between the hot main flow and the blade, placing the blade at a higher risk of burnout. Furthermore, deposition can alter the blade profile, deviating from optimal design conditions and reducing overall aero-thermal efficiency. Beyond the blade's exterior, particulate matter can also enter the turbine blade interior through the secondary air system. The cooling air temperature is below the softening temperature of the particulate matter, and the complex cooling structure interacts with it, resulting in a unique deposition mechanism for the particulate matter, making it difficult to predict the potential damage from deposition using relatively well-established high-temperature deposition mechanisms. Furthermore, the confined interior space amplifies the impact of deposition on blade performance and makes removal difficult. After entering the blade, particulate matter first reaches the cooling channel. In a common arrangement with turbulent ribs, these particles adhere to the channel's inner walls and, through their low thermal conductivity, hinder the cooling air from removing heat from the blade metal. They also accumulate at the rib corners, weakening the ribs' enhanced heat transfer effect. Furthermore, the deposits clog the cooling channel and increase flow losses. Therefore, a structure that can effectively reduce the concentration of particulate matter in the turbine blade's internal cooling channel, thereby minimizing the adverse effects of deposits on the cooling air's thermal performance, is urgently needed. However, the published literature on dust-proof structures applicable to internal cooling structures is very limited. Yang Xing et al. (PCN240010217) employed a bag-shaped sedimentation reduction structure at the front end of a turbine blade's cooling channel. While this structure captured particulate matter and increased cooling air turbulence, it did so at the expense of cooling air flow losses. Summary of the Invention

[0005] The object of the present invention is to provide a turbine blade having an internal cooling channel with a dust-proof structure, so as to solve the technical defect that the internal cooling channel of the existing turbine blade is difficult to capture particulate pollutants.

[0006] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0007] A turbine blade with a dust-proof structure in an internal cooling channel, wherein a swirl cavity 4 is opened between the U-shaped cooling channel 1 with ribs inside the turbine blade 9, and the U-shaped cooling channel 1 and the swirl cavity 4 are connected through a square nozzle 3 on the pressure side of the ribbed U-shaped cooling channel; after the cold air carrying particulate pollutants enters the U-shaped cooling channel 1 inside the turbine blade 9 rotating from the pressure side to the suction side, the particulate matter will be deflected toward the opposite side of the rotation direction under the action of the Coriolis force, and will be gathered in the inter-rib area on the pressure side of the U-shaped cooling channel, and then will be blown away by the inclined perturbation nozzle located on the U-shaped cooling channel at an acute angle to the flow direction of the cold air. Under the guidance of the flow rib 2, the particulate matter moves toward the leading edge of the inclined spoiler rib 2, and then enters the swirl chamber 4 through the square nozzle 3; the cold air carrying the particulate matter spirals forward in the swirl chamber 4, which on the one hand enhances the forced convection heat exchange capacity of the inner wall of the turbine blade cavity, and on the other hand, the increased tangential velocity near the wall makes it difficult for the particulate matter to settle in the swirl chamber 4; the top of the swirl chamber is a contraction section 5, which reaches the blade top dust removal hole 8 through the hollow channel of the hollow spoiler column 7 arranged in the U-shaped cooling channel elbow 6, and finally the particulate pollutants are discharged from the turbine blade 9, and the cleanliness of the cold air in the internal U-shaped cooling channel is significantly improved.

[0008] The turbine blades 9 and their internal cooling structures are in a rotating condition pointing from the pressure surface to the suction surface. The square nozzle 3 is arranged on the pressure surface side of the U-shaped cooling channel to ensure that the particles can be guided to a position close to the square nozzle under the action of the Coriolis force.

[0009] The swirl chamber 4 is arranged between the U-shaped cooling channels 1 and is connected to the air inlet path of the U-shaped cooling channels 1 through the square nozzle 3 .

[0010] The inclined spoiler ribs 2 in the U-shaped cooling channel 1 point toward the swirl cavity 4 along the cold air flow direction in the inlet air flow path, and the angle between the extending direction of the spoiler ribs 2 and the cold air flow direction in the cold air flow path is between 20° and 70°.

[0011] The square nozzle 3 is tangent to the pressure surface of the U-shaped cooling channel 1 and the swirl chamber 4 respectively, which reduces the flow loss and allows the cold air to be tangentially injected into the swirl chamber 4 to form a swirl.

[0012] The inclination direction of the square nozzle 3 is consistent with that of the spoiler rib 2 , which reduces flow loss on the one hand and makes it easier to form a cold air vortex pointing towards the blade tip in the vortex cavity 4 on the other hand.

[0013] The square nozzle 3 is not continuous, but is separated by multiple partitions 10. The flow direction size and position of the partition 10 are consistent with the flow direction section of the local inclined spoiler rib, and the height of the partition 10 is 0.5 to 3 times the height of the inclined spoiler rib; the presence of the partition 10 increases the stability of the structure and reduces the probability of particles escaping from the vortex chamber.

[0014] The top of the cyclone chamber 4 gradually shrinks, and its final size is equivalent to the dust removal hole on the blade top.

[0015] A hollow spoiler column 7 is arranged at the elbow 6 of the U-shaped cooling channel. The hollow spoiler column can enhance the turbulence of the cold air and improve the heat exchange capacity of the cold air. The hollow channel therein can allow the top of the contracted swirl cavity to pass through and directly reach the blade top dust removal hole 8.

[0016] The square nozzles 3 are arranged one by one between the first and second ribs of the air inlet passage, and the number thereof ranges from 3 to 7.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The swirl formed by the cold air in the swirl cavity gives the inner wall of the cavity a higher tangential velocity near the wall, making it difficult for particles to deposit in the swirl cavity.

[0019] (2) The present invention has a compact structure, and the swirl chamber arranged between the U-shaped cooling channels does not occupy the space of other cooling structures.

[0020] (3) The present invention utilizes rotation and rib-induced secondary flow to guide particles with a higher Stokes number than cold air to a specific area, thereby facilitating separation.

[0021] (4) The square nozzle of the present invention is arranged between the first and second spoiler ribs. Compared with the traditional dust removal holes arranged at the elbow, it can separate the particles from the U-shaped cooling channel earlier, thereby reducing the probability of particle deposition inside the blade.

[0022] (5) The present invention utilizes the dust removal holes on the blade top to significantly reduce the concentration of particulate matter in the internal cooling channel under limited cooling air consumption, improve the heat exchange between the cooling channels, and optimize the overall heat transfer uniformity of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 This is a view of the hub of the present invention facing the casing surface.

[0025] Figure 3 The migration trajectory of particles in the internal U-shaped cooling channel with ordinary dust removal holes.

[0026] Figure 4 The migration trajectory of particles in the internal U-shaped cooling channel with a dust-proof structure.

[0027] Figure 5 The concentration of particulate matter in the channel decreases and the cooling air consumption is shown.

[0028] Figure 6 is the Nusselt number distribution on the surface of the internal U-shaped cooling channel with a dustproof structure.

[0029] Among them: 1-U-shaped cooling channel, 2-turbine rib, 3-square nozzle, 4-swirl cavity, 5-contraction section, 6-U-shaped cooling channel elbow, 7-hollow spoiler column, 8-blade top dust removal hole, 9-turbine moving blade, 10-partition. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and examples. This example provides a detailed implementation method based on the above technical solution, but this example is only a specific implementation method of the present invention, and any equivalent changes based on the technical principles of the present invention fall within the scope of protection of the claims of the present invention.

[0031] like Figure 1 As shown, the present invention discloses a turbine blade with an internal cooling channel and a dust-proof structure. A swirl chamber 4 is defined between a U-shaped cooling channel 1 with inclined spoiler ribs 2 within the turbine blade 9. The U-shaped cooling channel 1 and the swirl chamber 4 are connected and maintained tangentially by a square nozzle 3. The top of the swirl chamber 4 gradually converges to form a contraction section 5, which flows directly to the blade tip dust removal hole 8 through a hollow spoiler column 7 arranged in the elbow 6 of the U-shaped cooling channel.

[0032] like Figure 1 As shown, the square nozzle 3 is not continuous, but is separated by multiple partitions 10. The flow direction size and position of the partition 10 are consistent with the flow direction section of the local inclined spoiler rib, and the height of the partition 10 is 0.5 to 3 times the height of the inclined spoiler rib; the presence of the partition 10 increases the stability of the structure and reduces the probability of particles escaping from the vortex chamber.

[0033] The present invention utilizes a swirl structure to reduce the concentration of particulate matter in the cooling channel inside the turbine blades. The working process is as follows: small-sized particles crushed by the high-speed rotating compressor blades enter the U-shaped cooling channel 1 inside the turbine blades 9 through the secondary air system. Under the rotation condition from the pressure surface to the suction surface, the particles are gathered to the pressure surface side of the cooling channel due to the Coriolis force. Then, under the guidance of the inclined spoiler ribs 2, the cold air carries the particles through the square nozzle 3 into the swirl chamber 4. Under the action of the cold air swirl, it is difficult for the particles to deposit on the inner wall of the swirl chamber 4 with a large tangential velocity. Therefore, they are carried by the cold air and spiral into the contraction section 5 at the top of the swirl chamber 4. Then, they reach the blade top dust removal hole 8 through the hollow channel of the hollow spoiler column 7 arranged in the elbow 6 of the U-shaped cooling channel. Finally, the particles are discharged from the turbine blades 9.

[0034] Figure 2This is a view of the hub facing the casing. From this angle, the tangency of the square nozzle 3, swirl chamber 4, and U-shaped cooling channel 1 is clearly visible. For the U-shaped cooling channel 1, the tangential connection minimizes flow losses. For the swirl chamber 4, the cold air tangentially incident through the square nozzle 3 forms a swirl flow within the swirl chamber, which not only discharges particles but also removes heat from the U-shaped cooling channel 1 through forced convection.

[0035] Figure 3 This is the migration trajectory of particles in an internal U-shaped cooling channel with conventional dust removal holes. The inclined ribs create a pair of vortices rotating in opposite directions within the cooling channel. The cooling air, carrying particles, collides repeatedly with the wall, increasing the probability of particle deposition. In the cooling channel elbow, only a few small particles are discharged from the blade tip dust removal holes with the cooling air, while the majority of particulate contaminants remain in the U-shaped cooling channel.

[0036] Figure 4 This is the migration trajectory of particulate matter in the internal U-shaped cooling channel with a dust-proof structure of the present invention. After entering the U-shaped cooling channel, the particles are continuously separated and enter the swirl chamber starting from the first square nozzle. The separation phenomenon is particularly obvious in the first three square nozzles. The particles spiral forward in the swirl chamber. Due to the inertia of the particles themselves and the continuous entry of cold air into the swirl chamber, the particles have difficulty flowing back into the U-shaped cooling channel. Ultimately, the particles converge in the contraction section at the top of the swirl chamber and flow out through the dust removal holes on the blade top. The concentration of particulate pollutants in the separated U-shaped cooling channel of the swirl structure is significantly reduced.

[0037] Figure 5 The reduction in particle concentration in the U-shaped cooling channel and the effect of cooling air consumption were analyzed quantitatively. Conventional dust removal holes have a very low particle separation efficiency, with 99.17% of particles remaining in the cooling channel after passing through the dust removal holes, showing almost no change. The invention, with the addition of a swirl dust-proof structure, reduced the particle concentration in the cooling channel to 42.82% while increasing cooling air consumption by only 1%, significantly improving particle separation efficiency compared to conventional dust removal holes.

[0038] Figure 6This is the Nusselt number distribution on the surface of the internal U-shaped cooling channel with a dustproof structure of the present invention. The U-shaped cooling channel is used for the flow of cold air from the compressor, which takes away the heat in the metal of the turbine blades in the form of forced convection heat exchange, thereby protecting the blades from being burned by high temperatures. However, in locations far away from the U-shaped cooling channel (for example, between two cooling channels that are far apart), cooling can only be carried out in the form of heat conduction, which has low cooling efficiency and will also cause obvious thermal stress in the blades. In the extremely high temperature and high-speed operating environment of the turbine blades, excessive thermal stress will significantly reduce the service life of the blades and cause safety hazards. The swirl chamber is arranged between the U-shaped cooling channels, and the swirl formed by the cold air strengthens the cold air heat exchange capacity of the inner wall of the swirl chamber, which can not only enhance the cold air protection capacity of these low heat exchange areas, but also improve the overall heat transfer uniformity of the blades.

[0039] In summary, in order to reduce the damage to aerodynamic characteristics and cooling performance caused by the deposition of particulate pollutants in the internal cooling channel, the present invention provides a turbine blade with a dust-proof structure in the internal cooling channel. Under the guidance of the rotation and rib-induced secondary flow, the inertia difference between the particulate matter and the cold air is utilized, and at the cost of a slight increase in cold air consumption, the particulate pollutants are efficiently separated from the cold air and discharged from the blade, thereby improving the cleanliness of the cold air in the internal cooling channel of the blade. The present invention has a simple structure and does not require special processing. It can be realized by using the currently commonly used turbine blade cooling structure processing technology. When using the present invention, a trade-off can be made between the cold air consumption, the particulate separation requirements, and the swirl chamber heat exchange requirements, and the appropriate square nozzle opening size, the number of square nozzles, and the size of the blade top dust removal hole can be selected.

[0040] Unless otherwise defined, all terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Claims

1. A turbine rotor blade with an internal cooling channel and a dust-proof structure, characterized in that: A swirl cavity (4) is provided between the U-shaped cooling channels (1) inside the turbine blades (9), and the U-shaped cooling channels (1) and the swirl cavity (4) are connected through a square nozzle (3) on the pressure side of the ribbed U-shaped cooling channels; after the cold air carrying particulate pollutants enters the U-shaped cooling channels (1) inside the turbine blades (9) rotating from the pressure side to the suction side, the particulate matter will be deflected toward the opposite side of the rotation direction under the action of the Coriolis force and will be gathered in the inter-rib area on the pressure side of the U-shaped cooling channels (1), and then, under the guidance of the inclined spoiler ribs (2) on the U-shaped cooling channels (1) which are at an acute angle to the flow direction of the cold air, the particulate matter will be moved to the opposite side of the rotation direction. The cooling air moves in the direction of the leading edge of the inclined spoiler rib (2), and then enters the swirl chamber (4) through the square nozzle (3) formed by the partition (10); the cold air entrained with the particulate matter spirals forward in the swirl chamber (4), which on the one hand strengthens the forced convection heat transfer capacity of the inner wall surface of the turbine blade cavity, and on the other hand, the increased tangential velocity near the wall makes it difficult for the particulate matter to settle in the swirl chamber (4); the top of the swirl chamber is a contraction section (5), which reaches the blade top dust removal hole (8) through the hollow channel of the hollow spoiler column (7) arranged at the U-shaped cooling channel elbow (6), and finally the particulate pollutants are discharged from the turbine blade (9), and the cleanliness of the cooling air inside the blade is significantly improved; The inclined spoiler ribs (2) in the U-shaped cooling channel (1) point toward the swirl cavity (4) along the cold air flow direction in the inlet air flow path, and the angle between the extending direction of the spoiler ribs (2) and the flow direction of the cold air in the cold air flow path is between 20° and 70°.

2. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The turbine blades (9) and the cooling structure inside them are in a rotating condition pointing from the pressure surface to the suction surface. The square nozzle (3) is arranged on the pressure surface side of the U-shaped cooling channel to ensure that the particles can be guided to a position close to the square nozzle under the action of the Coriolis force.

3. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The swirl chamber (4) is arranged between the U-shaped cooling channels (1) and is connected to the air inlet path of the U-shaped cooling channels (1) through the square nozzle (3).

4. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The square nozzle (3) is tangent to the pressure surface of the U-shaped cooling channel (1) and the swirl chamber (4), respectively, which reduces flow loss and allows the cold air to be injected tangentially into the swirl chamber (4) to form a swirl.

5. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The inclination direction of the square nozzle (3) is consistent with that of the spoiler rib (2), which reduces flow loss on the one hand and makes it easier to form a cold air vortex pointing towards the blade tip in the vortex cavity (4) on the other hand.

6. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The square nozzle (3) is not continuous, but is separated by a plurality of partitions (10). The flow direction size and position of the partition (10) are consistent with the flow direction cross section of the local inclined spoiler rib, and the height of the partition (10) is 0.5 to 3 times the height of the inclined spoiler rib. The existence of the partition (10) increases the stability of the structure and reduces the probability of particles escaping from the swirl chamber.

7. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The top of the cyclone chamber (4) gradually shrinks, and its final size is equivalent to the dust removal hole on the blade top.

8. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: A hollow spoiler column (7) is arranged at the elbow (6) of the U-shaped cooling channel. The hollow spoiler column can enhance the turbulence of the cold air and improve the heat exchange capacity of the cold air. The hollow channel therein can allow the top of the swirl cavity after contraction to pass through and directly reach the blade top dust removal hole (8).

9. The turbine rotor blade with a dust-proof structure for an internal cooling channel according to claim 1, characterized in that: The square nozzles (3) are arranged one by one between the first and second ribs of the air inlet path, and the number thereof is between 3 and 7.

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