A kind of ferrule cyclone gas turbine turbine blade cooling structure and blade

Abstract

The application relates to the technical field of turbine blade cooling, and provides a core-inserted rotational flow type gas turbine turbine blade cooling structure and a blade. The core-inserted rotational flow type gas turbine turbine blade cooling structure comprises a rotational flow cavity and a gas supply cavity which are arranged in the interior of a blade leading edge and are connected through rotational flow jet holes, the gas outlet of the rotational flow cavity is connected with the external environment of the blade, and the gas inlet of the gas supply cavity is connected with a cooling gas source outside the blade. The core-inserted rotational flow type gas turbine turbine blade cooling structure further comprises a rotational flow core which is inserted into the rotational flow cavity, and a cooling channel suitable for cooling gas flow is formed between the outer wall of the rotational flow core and the inner wall of the rotational flow cavity. The core-inserted rotational flow type gas turbine turbine blade cooling structure can force the cooling gas in the cooling channel to rotate around the rotational flow core at a high speed to cool the target surface, so that the heat exchange coefficient distribution is more uniform; and the rotational flow jet can also be prevented from gathering at the axis of the rotational flow cavity by separating from the inner wall of the rotational flow cavity, so that the mixing degree between the rotational flow jets is reduced.

Description

Technical Field

[0001] This invention relates to the field of turbine blade cooling technology, specifically to a core-insertion swirl gas turbine blade cooling structure and blade. Background Technology

[0002] Heavy-duty gas turbines operate under high-temperature, high-pressure gas conditions, constantly facing the risk of ablation, especially at the leading edge of the blades which directly bears the impact of the incoming flow. A specialized air-cooling structure is required to ensure the blades' operational safety. Swirl cooling is an internal cooling structure for turbine blades, custom-designed according to the shape of the blade's leading edge. It features high cooling efficiency, low aerodynamic losses, ease of manufacturing, and low cost. Existing swirl cooling technology employs a supply chamber and a swirl chamber arranged parallel along the blade height, connected by a row of jet holes. Cool air enters the swirl chamber from the supply chamber through the jet holes, forming a swirling flow under the constraint of the cylindrical swirl chamber wall to cool the target surface.

[0003] Since increasing the convective heat transfer area is an important means of improving the internal cooling effect, the design of swirling cooling also aims to maximize the diameter of the swirling cavity to increase the target surface area while ensuring the strength of the leading edge wall thickness. However, increasing the diameter of the swirling cavity also provides radial development space for the swirling jet, making it easier for the thin layer of cooling air to counteract centrifugal force under the action of the wall pressure gradient and detach from the target surface to flow into the axial space of the swirling cavity. This will further increase the mixing degree between the jet air, resulting in insufficient heat transfer intensity of the target surface, uneven distribution of heat transfer coefficient, and inefficient utilization of cooling air. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that the increase in the diameter of the swirl cavity in the prior art also provides the radial development space of the swirl jet, making it easy for the thin layer of cooling air to offset the centrifugal force under the action of the wall pressure gradient and to detach from the target surface and flow into the axial space of the swirl cavity. This will further increase the mixing degree between the jet air, resulting in insufficient heat transfer intensity of the target surface, uneven distribution of heat transfer coefficient, and insufficient utilization of cooling air. Therefore, the present invention provides a core-inserted swirl gas turbine blade cooling structure and blade.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] On one hand, the present invention provides a swirling gas turbine blade cooling structure with insert insert, including a swirling cavity and an air supply cavity disposed inside the leading edge of the blade and connected by a swirling jet hole. The outlet of the swirling cavity is connected to the external environment of the blade, and the inlet of the air supply cavity is connected to a cooling air source outside the blade. It also includes a swirling insert inserted into the swirling cavity, wherein a gap is left between the outer wall of the swirling insert and the inner wall of the swirling cavity to form a cooling channel suitable for the flow of cooling gas.

[0007] Furthermore, the hydraulic diameter of the swirl insert gradually decreases along the flow direction of the cooling gas, so that the flow area of ​​the cooling channel gradually increases.

[0008] Furthermore, it also includes a reinforcing connector disposed within the cooling channel, one end of which is connected to the outer wall of the vortex insert and the other end of which is connected to the inner wall of the vortex cavity.

[0009] Furthermore, the reinforcing connector is a rod-shaped or plate-shaped structure.

[0010] Furthermore, the surface curvature of the swirling ferrule is continuous and has no protruding structures.

[0011] Furthermore, the vortex insert is coaxially arranged with the vortex cavity.

[0012] Furthermore, the swirling cavity is a cylindrical cavity, and the cross-sectional shape of the swirling cavity is circular, elliptical, or a polygon with rounded edges.

[0013] Furthermore, a plurality of swirling jet holes are provided at intervals between the swirling cavity and the air supply cavity along the height direction of the blade.

[0014] Furthermore, each of the swirling jet orifices has a flattened structure to constrain the cooling gas into the swirling cavity as a thin-layer jet.

[0015] On the other hand, the present invention also provides a blade, including the ferrule swirl gas turbine blade cooling structure described in any of the above claims.

[0016] The technical solution of this invention has the following advantages:

[0017] The swirling gas turbine blade cooling structure provided by this invention forms a cooling channel by arranging a swirling insert in the swirling cavity. This forces the cooling gas in the cooling channel to cool the target surface in a high-speed swirling manner around the swirling insert, resulting in a more uniform heat transfer coefficient distribution. Furthermore, it can prevent the swirling jet from detaching from the inner wall of the swirling cavity and accumulating at the axis of the swirling cavity, reducing the degree of mixing between the swirling jets. This is beneficial for improving the heat transfer intensity between the cooling gas and the target surface and for making full use of the cooling gas. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the cooling structure of the turbine blade of the insert-type swirl gas turbine in an embodiment of the present invention;

[0020] Figure 2 This is a cross-sectional view of the cooling structure of the turbine blade of the insert-type swirl gas turbine in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram showing the positional relationship between the air supply chamber and the swirl chamber in the cooling structure of the insert-type swirl gas turbine blade in an embodiment of the present invention;

[0022] Figure 4 for Figure 3 The main view;

[0023] Figure 5 for Figure 3 Side view;

[0024] Figure 6 A schematic diagram of the target surface Nusselt number of the cooling structure for turbine blades in a swirl-type gas turbine with insert cores in the prior art.

[0025] Figure 7 This is a schematic diagram of the target surface Nusselt number of the cooling structure for the turbine blades of the insert-type swirl gas turbine in an embodiment of the present invention.

[0026] 1. Blade; 2. Swirl chamber; 3. Air supply chamber; 4. Swirl jet orifice; 5. Swirl insert; 6. Cooling channel. Detailed Implementation

[0027] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] like Figure 1 , Figure 2 As shown, this embodiment provides a swirling turbine blade cooling structure with a swirl insert, including a swirling cavity 2 and an air supply cavity 3 disposed inside the leading edge of the blade and connected by swirling jet holes 4. The outlet of the swirling cavity 2 is connected to the external environment of the blade 1, and the inlet of the air supply cavity 3 is connected to a cooling air source outside the blade 1. It also includes a swirling insert 5, inserted into the swirling cavity 2, with a gap between the outer wall of the swirling insert 5 and the inner wall of the swirling cavity 2 to form a cooling channel 6 suitable for the flow of cooling gas. For example, the surface curvature of the swirling insert 5 is continuous and without protruding structures. For example, the swirling insert 5 and the swirling cavity 2 can be coaxially arranged. For example, multiple swirling jet holes 4 can be spaced apart between the swirling cavity 2 and the air supply cavity 3 along the height direction of the blade 1.

[0032] The swirling gas turbine blade cooling structure provided in this embodiment forms a cooling channel by arranging a swirling insert 5 in the swirling cavity 2. This forces the cooling gas in the cooling channel to cool the target surface in a high-speed swirling manner around the swirling insert 5, resulting in a more uniform heat transfer coefficient distribution. Furthermore, it can prevent the swirling jet from detaching from the inner wall of the swirling cavity 2 and accumulating at the axis of the swirling cavity 2, reducing the mixing degree between the swirling jets. This is beneficial for improving the heat transfer intensity between the cooling gas and the target surface and for making full use of the cooling gas.

[0033] like Figure 3 , Figure 4 , Figure 5 As shown, specifically, the vortex cavity 2 can be a cylindrical cavity with a cross-sectional shape including but not limited to a circle, an ellipse, and a rounded polygon. The hydraulic diameter D of the vortex cavity 2 can range from 1mm to 100mm. For example, if the cross-section of the vortex cavity 2 is circular, D is preferably 40mm.

[0034] The length L of the swirling cavity 2 can range from 2D to 20D, with L preferably being 10D.

[0035] The swirling jet orifice 4 can have a flat structure to confine the cooling gas into the swirling cavity 2 as a thin-layer jet. The height H of the swirling jet orifice 4 is... j The value range can be 0.5D-2D, for example, H j The preferred value is 0.75D.

[0036] Among them, the width W of the swirling jet orifice 4 j The value range can be 0.5mm-10mm, for example, W j The preferred size is 5mm.

[0037] Among them, the width L of the swirling jet orifice 4 j The value range can be 1mm-50mm, for example, L j The preferred size is 10mm.

[0038] The number of swirling jet holes 4 can range from 5 to 20. For example, the number of swirling jet holes 4 is preferably 10.

[0039] The swirl insert 5 can be a cylindrical body with a constant hydraulic diameter or a cylindrical body with a variable hydraulic diameter. The cross-sectional shape of the swirl insert 5 is consistent with the cross-sectional shape of the swirl cavity 2, and the hydraulic diameter of the swirl insert 5 can range from 0.1D to 0.9D. When the swirl insert 5 adopts a cylindrical design with a variable hydraulic diameter, the hydraulic diameter at the downstream end should be smaller than that at the upstream end. In this case, the flow area of ​​the cooling channel gradually increases along the general direction of the cooling gas. For example, if the swirl insert 5 adopts a constant slope variable diameter design, the upstream end has a value of 0.25D, and the downstream end has a value of 0.85D.

[0040] The length of the swirl plug 5 can be in the range of 0.1LL, for example, the length of the swirl plug 5 is preferably L.

[0041] The swirl insert 5 can be installed in the swirl cavity 2 by welding, or it can be integrally formed with the blade 1.

[0042] A reinforcing connector can be provided, which can be a rod-shaped or plate-shaped structure. One end of the reinforcing connector is connected to the swirl insert 5, and the other end is connected to the inner wall of the swirl cavity 2 to increase the connection strength between the swirl insert 5 and the swirl cavity 2.

[0043] The Reynolds number Re is a commonly used dimensionless parameter for measuring the fluid flow state, and it is defined as follows:

[0044]

[0045] In the formula: ρ is the fluid density, with units of kg·m³. 3u is the fluid velocity in m / s; L is the characteristic length in m; μ is the fluid kinematic viscosity in Pa·s.

[0046] The Nusselt number (Nu) is a dimensionless number commonly used to measure heat transfer intensity, and it is defined as follows:

[0047]

[0048] In the formula: H is the convective heat transfer coefficient of the target surface, with units of W / (m²). 2 ·K); k is the thermal conductivity of the fluid, in W / (m·K); L is the characteristic length, in m.

[0049] like Figure 6 , Figure 7 As shown, the distribution of the Nusselt number on the target surface under the same jet Reynolds number conditions is compared between the swirling cooling structure in the prior art and the cooling structure in this embodiment. Calculations show that, compared to the prior art, the average Nusselt number on the target surface in this embodiment is increased by 8.3%, the efficient flow range of the jet (i.e., the area with a Nusselt number higher than 300) is expanded by 40%, the effective lateral flow range is expanded by 50%, and the consistency of the swirling coverage effect of different jets is greatly improved. Therefore, the cooling structure in this embodiment can effectively improve the heat transfer coefficient of the target surface, expand the efficient lateral and flow range of the swirling flow, enhance the consistency of swirling coverage, and improve the swirling cooling effect.

[0050] Another embodiment also provides a blade, including the ferrule swirl gas turbine blade cooling structure of any of the above.

[0051] In summary, the swirling gas turbine blade cooling structure and blades of this application, by arranging the swirling insert 5 coaxially in the swirling cavity 2, force the fluid to cool the target surface in a high-speed swirling manner around the swirling insert 5, thereby preventing the swirling jet from detaching from the wall and accumulating at the axis of the swirling cavity 2, and enhancing the heat transfer coefficient of the target surface.

[0052] The swirl-type gas turbine blade cooling structure and blades in this application improve the heat transfer intensity while taking into account the lateral coverage of the swirl, thus improving the uniformity of the heat transfer coefficient distribution.

[0053] The swirling gas turbine blade cooling structure and blades in this application can be manufactured by welding the swirling insert 5 to the blade as a separate insert or by casting it as an integral part of the blade. The process is mature and the cost is low.

[0054] The turbine blade cooling structure and blades of the swirl-type gas turbine in this application have a continuous surface curvature of the swirl insert 5 with no protruding structure, resulting in low aerodynamic losses.

[0055] The swirl-type gas turbine blade cooling structure and blades in this application are simple in form and easy to implement. They can improve the heat transfer intensity of the target surface, improve the swirl coverage effect, improve the utilization rate of cold air, and have low manufacturing cost and low aerodynamic loss.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A pin-fin, swirl-flow gas turbine turbine blade cooling structure, characterized by, The turbine blade cooling structure comprises a rotational flow cavity and a gas supply cavity, which are arranged inside the leading edge of the blade and are connected through a rotational flow jet hole, the gas outlet of the rotational flow cavity is connected with the external environment of the blade, and the gas inlet of the gas supply cavity is connected with a cooling gas source outside the blade; The turbine blade cooling structure further comprises a rotational flow insert, which is arranged in the rotational flow cavity, the outer wall contour of the rotational flow insert is consistent with the inner wall contour of the rotational flow cavity, and a cooling channel suitable for the flow of cooling gas is formed between the outer wall of the rotational flow insert and the inner wall of the rotational flow cavity. The swirling jet orifice has a flattened structure to confine the cooling gas into the swirling cavity as a thin-layer jet; the hydraulic diameter of the swirling cavity is D, and the height of the swirling jet orifice is H. j The value range is 0.5D-2D, and the width W of the swirling jet orifice is... j The value range is 0.5mm-10mm, and the width L of the swirling jet orifice is... j The value range is 1mm-50mm.

2. The turbine blade cooling structure according to claim 1, wherein The hydraulic diameter of the rotational flow insert gradually decreases in the flow direction of the cooling gas, so that the flow area of the cooling channel gradually increases.

3. The turbine blade cooling structure according to claim 1, wherein The turbine blade cooling structure further comprises a reinforcing connector, which is arranged in the cooling channel, one end of the reinforcing connector is connected with the outer wall of the rotational flow insert, and the other end of the reinforcing connector is connected with the inner wall of the rotational flow cavity.

4. The turbine blade cooling structure according to claim 3, wherein The reinforcing connector is in the form of a rod or a plate.

5. The turbine blade cooling structure according to claim 1, wherein The surface curvature of the rotational flow insert is continuous and free of protruding structures.

6. The turbine blade cooling structure according to claim 1, wherein The rotational flow insert is coaxially arranged with the rotational flow cavity.

7. The turbine blade cooling structure according to claim 1, wherein The rotational flow cavity is a columnar cavity, and the cross-sectional shape of the rotational flow cavity is circular, elliptical or polygonal with rounded corners.

8. The turbine blade cooling structure according to claim 1, wherein A plurality of rotational flow jet holes are arranged between the rotational flow cavity and the gas supply cavity in the height direction of the blade.

9. A vane, characterized by The turbine blade cooling structure comprises the turbine blade cooling structure according to any one of claims 1-8.

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