A kind of cooling structure and blade of counterflow passage type combustion turbine turbine blade

Abstract

This invention relates to the field of turbine blade cooling technology, and provides a counter-flow channel type gas turbine blade cooling structure and blade. The counter-flow channel type gas turbine blade cooling structure includes: a blade; several cooling channels disposed in the leading edge region of the blade, parallel to the blade height direction, and divided into co-current and counter-current channels according to the flow direction; the cooling channels are arranged side-by-side along the circumferential direction of the leading edge, and each cooling channel has an independent air inlet and outlet. The counter-flow channel type gas turbine blade cooling structure provided by this invention, by arranging multiple independent cooling channels side-by-side within the leading edge of the blade, reduces the non-cooled flow space of the cold air and increases the effective cooling area of ​​the cold air compared to a single swirl chamber in the prior art; furthermore, the multiple cold air streams are isolated from each other, avoiding mutual interference between the cold air streams, which is beneficial for fully utilizing the heat exchange potential of the cold air.

Description

Technical Field

[0001] This invention relates to the field of turbine blade cooling technology, specifically to a counter-flow 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, the present invention provides a counter-flow channel 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 counter-flow channel type cooling structure for gas turbine blades, comprising: a blade; a plurality of cooling channels disposed in the leading edge region of the blade, wherein the length direction of each cooling channel is consistent with the height direction of the blade; the cooling channels are arranged side by side along the circumferential direction of the leading edge, and each cooling channel has an independent air inlet and an air outlet; the cooling channels include a co-current channel and a counter-current channel, wherein the gas flow direction in the co-current channel is opposite to the gas flow direction in the counter-current channel.

[0007] Furthermore, the counter-flow channel type 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.

[0008] Furthermore, the counter-flow channel type gas turbine blade cooling structure also includes an exhaust chamber disposed inside the blade, the outlet of the exhaust chamber being connected to the external environment of the blade; the outlet of each cooling channel is connected to the inlet of the exhaust chamber.

[0009] Furthermore, both the exhaust chamber and the air supply chamber are arranged parallel to the cooling channel.

[0010] Furthermore, the exhaust chamber and the air supply chamber are at least partially overlapped in the orthogonal projection direction toward the leading edge of the blade.

[0011] Furthermore, along the flow direction of the cooling gas, the air supply chamber is provided with a first air outlet and a second air outlet at intervals, with the first air outlet located upstream of the second air outlet; along the flow direction of the cooling gas, the exhaust chamber is provided with a first air inlet and a second air inlet at intervals, with the first air inlet located upstream of the second air inlet; the air inlet of each of the forward flow channels is connected to the first air outlet, and the air outlet of each of the forward flow channels is connected to the second air inlet; the air inlet of each of the reverse flow channels is connected to the second air outlet, and the air outlet of each of the reverse flow channels is connected to the first air inlet; the forward flow channels and the reverse flow channels are alternately arranged.

[0012] Furthermore, the counter-flow channel gas turbine blade cooling structure also includes a first air supply ring, the concave surface of which is arranged facing the air supply chamber, and the air inlet of each of the downstream channels is connected to the first air outlet through the first air supply ring.

[0013] Furthermore, the counter-flow channel gas turbine blade cooling structure also includes a second air supply ring, the concave surface of which is arranged facing the air supply chamber, and the air inlet of each counter-flow channel is connected to the second air outlet through the second air supply ring.

[0014] 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.

[0015] On the other hand, the present invention also provides a blade, including the counter-flow channel 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 counter-flow cooling structure for gas turbine blades provided by this invention reduces the uncooled flow space of the cold air and increases the effective cooling area of ​​the cold air by arranging multiple independent cooling channels side by side in the leading edge of the blade, compared with the single swirl chamber in the prior art. 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. Moreover, the counter-flow arrangement of the co-current and counter-current channels can increase the heat exchange uniformity, which is conducive to further improving the cooling effect. 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 counter-flow channel gas turbine blade cooling structure in an embodiment of the present invention;

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

[0021] Figure 3 This is a schematic diagram showing the positional relationship between the first air supply ring and the second air supply ring in the counter-flow gas turbine blade cooling structure of the present invention.

[0022] Figure 4 This is a schematic diagram showing the positional relationship between the co-current channel and the counter-current channel in the counter-current channel gas turbine blade cooling structure of the embodiment of the present invention;

[0023] Figure 5 for Figure 3 The main view;

[0024] Figure 6 for Figure 3 A sectional view;

[0025] Figure 7 This is a comparison diagram of the heat flux density of the counter-flow channel gas turbine blade cooling structure in this embodiment of the invention and the swirl cooling structure in the prior art.

[0026] Figure 8 This is a comparison diagram of the heat flow of the counter-flow channel gas turbine blade cooling structure in this embodiment of the invention and the swirl cooling structure in the prior art.

[0027] 1. Blade; 2. Leading edge; 3. Cooling channel; 4. Air supply chamber; 5. Exhaust chamber; 6. First air supply ring; 7. Second air supply ring; 8. Co-current channel; 9. Counter-current channel. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] like Figure 1 , Figure 2 As shown, this embodiment provides a counter-flow channel type gas turbine blade cooling structure, including: a blade 1; a plurality of cooling channels 3 disposed in the inner wall region of the leading edge 2 of the blade 1, wherein the length direction of each cooling channel 3 is consistent with the height direction of the blade 1; the cooling channels 3 are arranged side by side along the circumferential direction of the leading edge 2, and each cooling channel 3 has an independent air inlet and an air outlet. The leading edge 2 of the blade 1 is generally curved. When setting the cooling channels 3, the cooling channels 3 can be placed as close as possible to the wall surface of the leading edge 2 of the blade 1. The overall arrangement of the multiple cooling channels 3 is adapted to the curved shape of the leading edge 2 of the blade 1 to achieve a better cooling effect.

[0033] The counter-flow 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 cooling channels 3 in parallel within the leading edge 2 of the blade 1, compared to the single swirl chamber in the prior art. 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.

[0034] like Figure 5 , Figure 6 As shown, specifically, the cross-sectional shape of the cooling channel 3 includes one or more of the following: circular, polygonal, polygonal with rounded edges, fan-shaped, and fan-shaped with rounded edges.

[0035] The hydraulic diameter D1 of the cooling channel 3 can range from 0.5mm to 10mm, and is preferably 5mm in this embodiment.

[0036] When multiple cooling channels 3 are arranged circumferentially along the leading edge 2, the multiple cooling channels 3 can all be located on the same semi-circular outline. For example, the diameter D2 of the outer ring formed by the multiple cooling channels 3 can range from 10mm to 100mm, and is preferably 40mm in this embodiment.

[0037] For example, the diameter D3 of the inner ring formed by multiple cooling channels 3 can range from 0.5D2 to 0.9D2, and in this embodiment, it is preferably 0.75D2.

[0038] For example, the flow length L2 of the cooling channel 3 can range from 2D2 to 10D2, and in this embodiment, it is preferably 6.5D2.

[0039] The cooling structure of the blade 1 also includes an air supply chamber 4, which is disposed inside the blade 1. The air inlet of the air supply chamber 4 is connected to a cooling air source. The air inlet of each cooling channel 3 is connected to the air outlet of the air supply chamber 4. For example, the air supply chamber 4 can be a cylindrical cavity with a rectangular cross-section, and the air supply chamber 4 and each cooling channel 3 are arranged parallel to each other.

[0040] The length L1 of the air supply chamber 4 can range from D2 to 10D2, and is preferably 12.5D2 in this embodiment.

[0041] The width W1 of the air supply chamber 4 can range from 0.5D2 to 2D2, and in this embodiment, D2 is preferred.

[0042] The height H1 of the air supply chamber 4 can range from 0.5D2 to 2D2, and is preferably 0.75D2 in this embodiment.

[0043] The counter-flow 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. The outlet of each cooling channel 3 is connected to the inlet of the exhaust chamber 5. For example, the exhaust chamber 5 can be a cylindrical cavity with a semi-circular cross-section, and the curved surface of the exhaust chamber 5 can face the cooling channel 3. The exhaust chamber 5 is arranged parallel to each cooling channel 3. Spatially, one side of the exhaust chamber 5 is the air supply chamber 4, and the other side is each cooling channel 3.

[0044] In this configuration, the exhaust chamber 5 and the air supply chamber 4 are at least partially overlapped in the direction of the positive projection toward the leading edge 2 of the blade 1.

[0045] The arc diameter D4 of the exhaust chamber 5 can range from 0.3D2 to 0.8D2, and is preferably 0.5D2 in this embodiment.

[0046] The length of the exhaust chamber 5 can range from D2 to 10D2, and is preferably 5D2 in this embodiment.

[0047] The height difference H2 between the air supply chamber 4 and the exhaust chamber 5 can range from 0.1D2 to 0.5D2, and is preferably 0.25D2 in this embodiment.

[0048] The height difference H3 between the air supply chamber 4 and the uppermost cooling channel 3 can range from 0 to D2, and is preferably 0.25D2 in this embodiment.

[0049] like Figure 3 , Figure 4As shown, the cooling channel 3 includes a co-current channel 8 and a counter-current channel 9; a first air outlet and a second air outlet are spaced apart on the air supply chamber 4 along the flow direction of the cooling gas, with the first air outlet located upstream of the second air outlet; a first air inlet and a second air inlet are spaced apart on the exhaust chamber 5 along the flow direction of the cooling gas, with the first air inlet located upstream of the second air inlet; the air inlet of each co-current channel 8 is connected to the first air outlet, and the air outlet of each co-current channel 8 is connected to the second air inlet; the air inlet of each counter-current channel 9 is connected to the second air outlet, and the air outlet of each counter-current channel 9 is connected to the first air inlet. For example, the co-current channels 8 and the counter-current channels 9 can be evenly staggered in the circumferential direction of the leading edge 2, and the total number N of cooling channels 3 can range from 6 to 20. Increasing the number of cooling channels 3 means reducing the spacing between them, which helps improve circumferential cooling uniformity. However, this reduces the single-channel cold air flow rate of each cooling channel 3, weakening the heat transfer coefficient of each channel. Therefore, the number of cooling channels 3 is limited by D2 and D1, and the number must be selected by comprehensively considering both cooling uniformity and flow resistance. In this embodiment, the preferred number of cooling channels 3 is 9, with 5 co-current channels 8 and 4 counter-current channels 9.

[0050] The counter-current channel gas turbine blade cooling structure also includes a first air supply ring 6, with its concave surface facing the air supply chamber 4. The air inlet of each co-current channel 8 is connected to a first air outlet via the first air supply ring 6. The structure also includes a second air supply ring 7, with its concave surface facing the air supply chamber 4. The air inlet of each counter-current channel 9 is connected to a second air outlet via the second air supply ring 7. Both the first and second air supply rings 6 and 7 are connected to the air supply chamber 4 at both ends, and the exhaust chamber 5 can pass through the inner rings of the first and second air supply rings 6 and 7. The first and second air supply rings 6 and 7 face each other, with the cooling channel 3 located between them. One end of the air inlet of all co-current channels 8 extends into the first air supply ring 6 via the side of the first air supply ring 6 facing the second air supply ring 7, and one end of the air outlet of all co-current channels 8 is connected to the downstream end of the exhaust chamber 5. Similarly, one end of the air inlet of all the counter-current channels 9 extends into the second air supply ring 7 via the side of the second air supply ring 7 facing the first air supply ring 6, and one end of the air outlet of all the counter-current channels 9 is connected to the upstream of the exhaust chamber 5. This arrangement, with the co-current channel 8 and the counter-current channel 9 in opposition, can increase the uniformity of heat exchange and improve the cooling effect.

[0051] The height of the straight segment of the first air supply ring 6 and the second air supply ring 7 can be in the range of 0.3D2 to 0.8D2, and is preferably 0.5D2 in this embodiment.

[0052] The length L3 of the first air supply ring 6 and the second air supply ring 7 ranges from 0.1D2 to D2, and is preferably 0.5D2 in this embodiment.

[0053] The jet Reynolds number is a dimensionless parameter used to evaluate the jet flow state, and it is defined as follows:

[0054]

[0055] In the formula: ρ is the fluid density, in kg·m3; u is the fluid velocity, in m / s; L is the characteristic length, i.e., the hydraulic diameter of the jet or cooling channel, in m; μ is the fluid kinematic viscosity coefficient, in Pa·s.

[0056] 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 7 and Figure 8 As shown, the target surface heat flux density of the blade 1 cooling structure in this embodiment is increased by 12% to 84% compared to the prior art, the target surface area is increased by 110%, and the total heat flow is increased by 139% to 291%, which can meet the requirements of efficient cooling of the leading edge 2.

[0057] Another embodiment also provides a blade, including the blade 1 cooling structure of any of the above.

[0058] In summary, the counter-flow cooling structure and blades of the gas turbine in this application reduce the non-cooled flow space of the cold air, increase the effective cooling area of ​​the cold air, increase the heat exchange uniformity, and isolate multiple cold air streams from each other by arranging multiple independent counter-flow cooling channels 3 in the wall of the leading edge 2 of the blade 1.

[0059] 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 counter-current channel gas turbine blade cooling structure, characterized in that, include: blade; Several cooling channels are disposed in the leading edge region of the blade, and the length direction of each cooling channel is consistent with the height direction of the blade; the cooling channels are arranged side by side along the circumferential direction of the leading edge, and each cooling channel has an independent air inlet and air outlet; when multiple cooling channels are arranged along the circumferential direction of the leading edge, the multiple cooling channels are located on the same semi-circular outline. The cooling channel includes a co-current channel and a counter-current channel, with the gas flow direction in the co-current channel being opposite to that in the counter-current channel; it also includes an air supply chamber disposed within the blade, with the air inlet of the air supply chamber connected to a cooling air source; The air inlet of each of the cooling channels is connected to the air outlet of the air supply chamber; It also includes an exhaust chamber, which is disposed inside the blade, and the outlet of the exhaust chamber is connected to the external environment of the blade. The air outlet of each of the cooling channels is connected to the air inlet of the exhaust chamber; Along the flow direction of the cooling gas, the air supply chamber is provided with a first air outlet and a second air outlet at intervals, and the first air outlet is located upstream of the second air outlet; Along the flow direction of the cooling gas, the exhaust chamber is provided with a first air inlet and a second air inlet at intervals, and the first air inlet is located upstream of the second air inlet; The air inlet of each of the following channels is connected to the first air outlet, and the air outlet of each of the following channels is connected to the second air inlet; The air inlet of each of the counterflow channels is connected to the second air outlet, and the air outlet of each of the counterflow channels is connected to the first air inlet.

2. The counter-flow channel gas turbine blade cooling structure according to claim 1, characterized in that, Both the exhaust chamber and the air supply chamber are arranged parallel to the cooling channel.

3. The counter-flow channel gas turbine blade cooling structure according to claim 2, characterized in that, The exhaust chamber and the air supply chamber are at least partially overlapped in the orthographic projection direction toward the leading edge of the blade.

4. The counter-flow channel gas turbine blade cooling structure according to claim 3, characterized in that, The downstream channel and the upstream channel are alternately arranged.

5. The counter-flow channel gas turbine blade cooling structure according to claim 4, characterized in that, It also includes a first air supply ring, the concave surface of which is arranged facing the air supply chamber, and the air inlet of each of the downstream channels is connected to the first air outlet through the first air supply ring.

6. The counter-flow channel type gas turbine blade cooling structure according to claim 5, characterized in that, It also includes a second air supply ring, the concave surface of which is arranged facing the air supply chamber, and the air inlet of each of the counterflow channels is connected to the second air outlet through the second air supply ring.

7. The counter-flow 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, polygonal with rounded edges, fan-shaped, and fan-shaped with rounded edges.

8. A blade, characterized in that, The included counter-flow gas turbine blade cooling structure according to any one of claims 1-7.

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