A multi-spiral passage type gas turbine turbine blade cooling structure and blade

Abstract

This invention relates to the field of turbine blade cooling technology, and provides a multi-spiral channel gas turbine blade cooling structure and blade. The multi-spiral channel gas turbine blade cooling structure includes: a blade; several cooling channels spaced apart along the height direction of the blade within the leading edge region of the blade; each cooling channel is a spiral channel with several turns, and each cooling channel has an independent air inlet and outlet. The multi-spiral channel gas turbine blade cooling structure provided by this invention, by arranging multiple independent spiral cooling channels at intervals within the leading edge of the blade, reduces the non-cooled flow space of the cooling air and increases the effective cooling area of ​​the cooling air compared to a single swirl chamber in the prior art. This allows the cooling air to fully exchange heat within the leading edge wall, increasing heat exchange uniformity; furthermore, the multiple cooling air streams are isolated from each other, avoiding mutual interference between the cooling air streams and facilitating the full utilization of the cooling air's heat exchange potential.

Description

Technical Field

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

[0002] The working medium of gas turbine blades is high-temperature, high-pressure gas, the temperature of which far exceeds the melting point of the nickel-based alloy material of the blade substrate. Therefore, a rational and efficient cooling structure must be designed to protect the blades and reduce the risk of ablation with minimal cooling air. The leading edge of the turbine blade, which directly bears the impact of the gas, is the area under the highest heat load. The cooling design for this leading edge also needs to employ a structure with the highest efficiency in utilizing cooling air.

[0003] Existing technology includes a swirling cooling structure, mainly comprising a swirling cavity, an air supply cavity, and a swirling jet orifice connecting the two, located inside the leading edge of the blade. During cooling, cooling gas enters the swirling cavity from the air supply cavity through the swirling jet orifice. The cold gas jet generates radial swirling on the target surface, cooling the target surface. However, this cooling structure also generates crossflow, which interferes with the operation of the swirling jet. Furthermore, the swirling jets are prone to mutual interference, causing some jets to detach from the target surface under the action of the pressure gradient and flow prematurely into the axial space of the swirling cavity, thus losing their function of cooling the target surface and failing to fully utilize the heat exchange potential of the cold gas. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that the cooling structure in the prior art will generate crossflow, which will interfere with the operation of the swirling jet. Moreover, the swirling jets are also prone to mutual interference, causing some jets to detach from the target surface under the action of pressure gradient and flow into the axial space of the swirling cavity in advance, thus losing the function of cooling the target surface and failing to fully utilize the heat exchange potential of the cold gas. Therefore, a multi-spiral channel gas turbine blade cooling structure and blade are provided.

[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 multi-spiral channel gas turbine blade cooling structure, comprising: a blade; a plurality of cooling channels, which are spaced apart along the height direction of the blade in the leading edge region of the blade; each cooling channel is a spiral channel with several turns, and each cooling channel has an independent air inlet and an air outlet.

[0007] Furthermore, the multi-helical channel gas turbine blade cooling structure also includes an inner cooling cavity, which is disposed in the leading edge region of the blade. The axial direction of the inner cooling cavity is consistent with the height direction of the blade. Each of the cooling channels is arranged around the outer periphery of the inner cooling cavity in the circumferential direction, and the air outlet of each cooling channel is connected to the inner cooling cavity.

[0008] Furthermore, the multi-spiral channel gas turbine blade cooling structure also includes an air supply chamber disposed inside the blade, wherein the air inlet of the air supply chamber is connected to a cooling air source; and the air inlet of each cooling channel is connected to the air outlet of the air supply chamber.

[0009] Furthermore, the air supply chamber is arranged parallel to the inner cooling chamber, and at least partially coincides with the inner cooling chamber in the orthogonal projection direction toward the leading edge of the blade; each cooling channel is connected to the air supply chamber through an air inlet section extending radially along the inner cooling chamber.

[0010] Furthermore, the multi-spiral channel gas turbine blade cooling structure also includes an exhaust chamber disposed inside the blade. The outlet of the exhaust chamber is connected to the external environment of the blade, and the inlet of the exhaust chamber is connected to the outlet of the inner cooling chamber.

[0011] Furthermore, the diameter of the exhaust chamber is the same as the outer diameter of the cooling channel.

[0012] Furthermore, along the axial direction of the inner cooling cavity, the spacing between two adjacent cooling channels is the same.

[0013] Furthermore, the cross-sectional shape of the cooling channel includes one or more of the following: circular, polygonal, polygonal with rounded edges, fan-shaped, and fan-shaped with rounded edges.

[0014] On the other hand, the present invention also provides a blade, including the multi-spiral channel gas turbine blade cooling structure described in any of the above claims.

[0015] The technical solution of this invention has the following advantages:

[0016] The multi-spiral channel gas turbine blade cooling structure provided by this invention, by arranging multiple independent spiral cooling channels at intervals within the leading edge of the blade, reduces the non-cooled flow space of the cooling air and increases the effective cooling area of ​​the cooling air compared to the single swirl chamber in the prior art. This allows the cooling air to fully exchange heat within the leading edge wall, increasing the heat exchange uniformity. Furthermore, the multiple streams of cooling air are isolated from each other, avoiding mutual interference between the cooling air streams and facilitating the full utilization of the cooling air's heat exchange potential. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the multi-spiral channel gas turbine blade cooling structure in an embodiment of the present invention;

[0019] Figure 2 This is a longitudinal sectional view of the multi-spiral channel gas turbine blade cooling structure in an embodiment of the present invention;

[0020] Figure 3 This is a cross-sectional view of the multi-spiral channel gas turbine blade cooling structure in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram showing the positional relationship between the cooling channel and the air supply chamber in the multi-spiral channel gas turbine blade cooling structure of this invention.

[0022] Figure 5 for Figure 4 The main view;

[0023] Figure 6 for Figure 4 A cross-sectional view;

[0024] Figure 7 for Figure 4 A longitudinal sectional view;

[0025] Figure 8 for Figure 4 Side view;

[0026] Figure 9 This is a comparison diagram of the heat flux density of the multi-spiral channel gas turbine blade cooling structure in this invention and the swirl cooling structure in the prior art.

[0027] Figure 10 This is a comparison diagram of the heat flow of the multi-spiral channel gas turbine blade cooling structure in this embodiment of the invention and the swirl cooling structure in the prior art.

[0028] 1. Blade; 2. Leading edge; 3. Cooling channel; 4. Air supply chamber; 5. Exhaust chamber; 6. Internal cooling chamber; 7. Intake section. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] like Figure 1 As shown, this embodiment provides a multi-spiral channel gas turbine blade cooling structure, including: a blade 1; a plurality of cooling channels 3, which are spaced apart along the height direction of the blade 1 in the leading edge 2 region of the blade 1; each cooling channel 3 is a spiral channel with several turns, and each cooling channel 3 has an independent air inlet and air outlet.

[0034] The spiral cooling channel 3 is arranged within the wall of the leading edge 2, thus the inner wall of the cooling channel 3 serves as the cooling target surface. Cooling air flows multiple times within the wall of the leading edge 2, completing convective heat transfer to the wall surface, while simultaneously increasing the temperature of the cooled air. During the cooling process, if the number of turns in the cooling channel 3 is too small, heat transfer will be insufficient, resulting in low utilization of the cooled air; if the number of turns is too large, the cooled air will overheat, leading to an excessively large local temperature gradient on the wall surface. Therefore, the number of turns in the cooling channel 3 needs to be reasonably selected according to the actual situation, ranging from 2 to 6 turns; in this embodiment, 3 turns are preferred. Figure 7 , Figure 8As shown, the hydraulic diameter D1 of the cooling channel 3 can range from 0.5mm to 10mm, and is preferably 5mm in this embodiment. The pitch L2 of the cooling channel 3 can range from 0.1D2 to D2, and is preferably 0.25D2 in this embodiment. The number N of cooling channels 3 can range from 5 to 20, and is preferably 10 in this embodiment.

[0035] The multi-spiral channel gas turbine blade cooling structure provided in this embodiment reduces the non-cooled flow space of the cold air and increases the effective cooling area of ​​the cold air by arranging multiple independent spiral cooling channels 3 at intervals in the leading edge 2 of the blade 1, compared with the single swirl chamber in the prior art. This allows the cooling air to fully exchange heat in the wall of the leading edge 2, increasing the heat exchange uniformity. Furthermore, the multiple cold air streams are isolated from each other, avoiding mutual interference between the cold air streams, which is conducive to fully utilizing the heat exchange potential of the cold air.

[0036] like Figure 2 , Figure 3 As shown, the multi-spiral channel gas turbine blade cooling structure also includes an inner cooling chamber 6, located within the leading edge 2 region of the blade 1. The axial direction of the inner cooling chamber 6 is aligned with the height direction of the blade 1. Each cooling channel 3 is arranged circumferentially around the inner cooling chamber 6, and the outlet of each cooling channel 3 is connected to the inner cooling chamber 6. During the cooling process, the cool air undergoes sufficient heat exchange within the wall of the leading edge 2 before entering the inner cooling chamber 6, where it undergoes further convective heat exchange on the inner side of the wall of the leading edge 2, and then exits the blade 1 through the exhaust chamber 5. This arrangement further improves the cooling effect on the blade 1.

[0037] The inner cooling cavity 6 can be a cylindrical cavity with a circular cross-section. The diameter D2 of the inner cooling cavity 6 can range from 10mm to 100mm, and is preferably 40mm in this embodiment. The length L3 of the inner cooling cavity 6 can range from 5D2 to 15D2, and is preferably 7.5D2 in this embodiment. Along the axial direction of the inner cooling cavity 6, the spacing between two adjacent cooling channels 3 is the same. This arrangement helps to improve the uniformity of cooling.

[0038] like Figure 4 As shown, the multi-spiral channel gas turbine blade cooling structure also includes an air supply chamber 4. For example, the air supply chamber 4 can be a cylindrical cavity with a rectangular cross-section. The air supply chamber 4 is located inside the blade 1, and the air inlet of the air supply chamber 4 is connected to the cooling air source. The air inlet of each cooling channel 3 is connected to the air outlet of the air supply chamber 4.

[0039] The air supply chamber 4 is arranged parallel to the inner cooling chamber 6. The air supply chamber 4 can be located on the side of the inner cooling chamber 6 away from the leading edge 2, and at least partially coincides with the inner cooling chamber 6 in the orthogonal projection direction toward the leading edge 2 of the blade 1. Each cooling channel 3 is connected to the air supply chamber 4 through an air inlet section 7 extending radially along the inner cooling chamber 6. This arrangement can reduce the air resistance when the cooling gas enters the cooling channel 3 from the air supply chamber 4.

[0040] like Figure 5 , Figure 6 As shown, the length L1 of the air supply chamber 4 can range from 5D² to 25D², and is preferably 12.5D² in this embodiment. The width W1 of the air supply chamber 4 can range from 0.5D² to 2D², and is preferably D² in this embodiment. The height H1 of the air supply chamber 4 can range from 0.5D² to 2D², and is preferably 0.75D² in this embodiment.

[0041] The multi-spiral channel gas turbine blade cooling structure also includes an exhaust chamber 5, which is located inside the blade 1. The outlet of the exhaust chamber 5 is connected to the external environment of the blade 1, and the inlet of the exhaust chamber 5 is connected to the outlet of the inner cooling chamber 6.

[0042] The diameter D3 of the exhaust chamber 5 is the same as the outer diameter of the cooling channel 3. The length L4 of the exhaust chamber 5 can range from D2 to 10D2, and is preferably 5D2 in this embodiment.

[0043] The jet Reynolds number is a dimensionless parameter used to evaluate the jet flow state, and it is defined as follows:

[0044]

[0045] In the formula: ρ is the fluid density, with units of kg·m³. 3 u is the fluid velocity in m / s; L is the characteristic length, i.e., the hydraulic diameter of the jet orifice or cooling channel in m; μ is the fluid kinematic viscosity in Pa·s.

[0046] Numerical simulations were performed on the swirl cooling structure in the prior art and the blade 1 cooling structure of this embodiment. The target surface heat flux density and target surface heat flow rate within the Reynolds number range of 5000 to 20000 were calculated and compared. The comparison results are as follows: Figure 9 and Figure 10 As shown, the target surface heat flux density of the blade 1 cooling structure in this embodiment is increased by 63% to 75% compared to the prior art, the target surface area is increased by 40%, and the total heat flux is increased by 132% to 149%, which can meet the requirements of efficient cooling of the leading edge 2.

[0047] Another embodiment also provides a blade including the multi-helix channel gas turbine blade cooling structure of any of the above.

[0048] In summary, the multi-spiral channel gas turbine blade cooling structure and blade of this application, by designing the traditional swirl chamber of the leading edge 2 into parallel multi-circle spiral cooling channels 3, increases the contact area between the cold air and the wall of the leading edge 2, improves the target surface heat transfer coefficient, avoids cold air stagnation, fully explores the cooling potential of the cold air, and significantly improves the cooling effect of the leading edge 2, and has good application prospects.

[0049] 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 multi-spiral channel gas turbine blade cooling structure, characterized in that, include: blade; Several cooling channels are spaced apart along the height direction of the blade in the leading edge region of the blade; each cooling channel is a spiral channel with several turns, and each cooling channel has an independent air inlet and air outlet. An internal cooling cavity is disposed in the leading edge region of the blade, and the axial direction of the internal cooling cavity is consistent with the height direction of the blade; Each of the cooling channels is arranged around the outer periphery of the inner cooling cavity in the circumferential direction, and the air outlet of each cooling channel is connected to the inner cooling cavity.

2. The multi-spiral channel gas turbine blade cooling structure according to claim 1, characterized in that, It also includes an air supply chamber, which is disposed inside the blade, and the air inlet of the air supply chamber is connected to a cooling air source; The air inlet of each cooling channel is connected to the air outlet of the air supply chamber.

3. The multi-spiral channel gas turbine blade cooling structure according to claim 2, characterized in that, The air supply chamber is arranged parallel to the inner cooling chamber, and the air supply chamber is at least partially overlapped with the inner cooling chamber in the orthogonal projection direction toward the leading edge of the blade; Each of the cooling channels is connected to the air supply chamber via an air intake section extending radially along the inner cooling chamber.

4. The multi-spiral channel gas turbine blade cooling structure according to claim 1, characterized in that, It also includes an exhaust chamber disposed inside the blade, the outlet of the exhaust chamber being connected to the external environment of the blade, and the inlet of the exhaust chamber being connected to the outlet of the inner cooling chamber.

5. The multi-spiral channel gas turbine blade cooling structure according to claim 4, characterized in that, The diameter of the exhaust chamber is the same as the outer diameter of the cooling channel.

6. The multi-spiral channel gas turbine blade cooling structure according to claim 1, characterized in that, Along the axial direction of the inner cooling cavity, the spacing between two adjacent cooling channels is the same.

7. The multi-spiral channel gas turbine blade cooling structure according to claim 1, characterized in that, The cross-sectional shape of the cooling channel includes one or more of the following: circular, polygonal, and fan-shaped.

8. A blade, characterized in that, The multi-spiral channel gas turbine blade cooling structure includes any one of claims 1-7.

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