Novel small-channel double-wall cooling structure for supplying air in separated cavities

Abstract

The invention relates to the technical field of cooling of turbine blades of gas turbines, and discloses a novel small-channel double-layer-wall cooling structure for supplying gas through cavities, an internal gas supply channel of a double-layer wall is divided into small cavity-divided gas supply areas (namely gas supply cavities) through flow baffles, and gas film holes are formed in outer layer plates corresponding to the cavity-divided gas supply areas. The flow regulation and control of each air film hole can be realized and the heat exchange can be enhanced by supplying air through the sub-cavities; according to the double-wall cooling structure, cold air is prevented from moving in the air supply channel, meanwhile, the low heat exchange area between the impact holes is improved through outflow of the air film holes, and the overall cooling efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine blade cooling, and discloses a novel small channel double-wall cooling structure with divided-cavity air supply. Background Art

[0002] The gas turbine engine consists of a compressor combustion chamber and a turbine. The high-pressure air compressed by the compressor is mixed with the fuel in the combustion chamber for combustion. The high-temperature and high-pressure gas after combustion enters the turbine to expand and do work. At this time, the turbine blades and other components are exposed to a high-temperature environment. Therefore, the turbine guide vanes and blades must be made of materials that can withstand such high temperatures. However, the increase in the temperature before the turbine is crucial to the improvement of the efficiency of the entire engine. Therefore, in order to pursue the goals of high efficiency and high power density, cooling technology must be applied to increase the life of the blades to ensure the safe operation of the turbine.

[0003] Double-wall cooling, as a micro-scale cooling technology for turbine blades, has been widely studied in recent years. Typical double-wall cooling has the following advantages: the heat transfer scale can be reduced from the blade scale (0.5-1.5cm) to the cooling cavity scale (0.5-1.5mm), the heat transfer coefficient is high, and the heat transfer area is large; due to the internal cooling of the external high-temperature gas, the thin outer wall of the blade increases the heat transfer, and the cooling gas consumption and local heat transfer can be adjusted according to the external heat load distribution in different areas.

[0004] Double-wall cooling uses a combination of impingement cooling, column rib turbulence and external air film cooling. The internal flow is more complicated due to the impingement jet, wall shear, turbulence column and air film hole outflow. In addition, the double-wall cooling system is easily affected by cold air migration when there is a pressure gradient outside the blade under real working conditions, which will cause uneven distribution of air film hole flow and seriously affect blade cooling. Summary of the invention

[0005] The purpose of the present invention is to provide a new type of small channel double-wall cooling structure with divided cavity air supply, which can improve the low heat exchange area between the impact holes, enhance the overall cooling capacity, effectively improve the cold air migration phenomenon in the internal channel of the impact divergent double-wall blade, and improve the uniformity of the blade temperature distribution.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0007] A novel small channel double-wall cooling structure with divided cavity air supply comprises an inner plate and an outer plate sleeved on the outer periphery of the inner plate, an air supply channel for air flow is arranged between the inner plate and the outer plate; a plurality of baffles are arranged between the inner plate and the outer plate, and the plurality of baffles are used to divide the air supply channel into a plurality of independent air supply cavities; an impact hole penetrating the wall thickness of the inner plate is provided on the inner plate corresponding to each air supply cavity, and an air film hole penetrating the wall thickness of the outer plate is provided on the outer plate corresponding to each air supply cavity.

[0008] Furthermore, the air film holes on the outer plate are in a multi-row structure, and adjacent rows of air film holes are arranged in a staggered or sequential manner; the impact holes on the inner plate are in a multi-row structure, and adjacent rows of impact holes are arranged in a staggered or sequential manner.

[0009] Furthermore, the thickness of the outer layer plate ranges from 1 to 2.5 times the diameter of the air film hole.

[0010] Furthermore, the angle between the central axis of each air film hole and the tangent of the outer plate where the air film hole is located ranges from 20 to 160 degrees.

[0011] Furthermore, the height of the air supply channel is 0.5 to 2.5 times the diameter of the air film hole.

[0012] Furthermore, the thickness of the inner layer plate is 0.5 to 1.5 times the diameter of the air film hole.

[0013] Furthermore, the tangential angle between the center axis of the impact hole and the wall surface of the inner plate where the impact hole is located is 90 degrees.

[0014] Furthermore, the diameter of the impact hole 5 is in the range of 0.5 to 2 times the diameter of the air film hole.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The double-wall cooling structure with divided-cavity air supply small channels of the present invention improves the low heat exchange area between the impact holes by setting divided cavities in the cooling channels inside the double-wall, thereby improving the overall cooling capacity and effectively improving the cold air migration phenomenon in the internal channels of the impact-diverging double-wall blades.

[0017] 2. The double-wall cooling structure of the divided-cavity air supply small channel of the present invention can significantly improve the average comprehensive cooling efficiency of the surface, and can improve the uniformity of the temperature distribution of the blade, thereby improving the comprehensive cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a novel small channel double-wall cooling structure with divided-cavity air supply in an embodiment;

[0019] Among them, 1. Inner plate; 2. Outer plate; 3. Baffle; 4. Impact hole; 5. Air film hole. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0021] Example

[0022] See also Figure 1 A new type of small channel double-wall cooling structure with divided cavity air supply, comprising an inner plate 1 and an outer plate 2 sleeved on the outer periphery of the inner plate 1, an air supply channel for air flow is arranged between the inner plate 1 and the outer plate 2; a plurality of baffle plates 3 are arranged between the inner plate 1 and the outer plate 2, and the plurality of baffle plates 3 are used to divide the air supply channel into a plurality of independent air supply cavities; an impact hole 4 penetrating the wall thickness of the inner plate 1 is opened on the inner plate 1 corresponding to each of the air supply cavities, and an air film hole 5 penetrating the wall thickness of the outer plate 2 is opened on the outer plate 2 corresponding to each of the air supply cavities.

[0023] In this embodiment, cold air is formed into an impact jet by the impact hole 4 and impacts the inner wall surface of the outer plate 2. The impact jet impacts the inner wall surface of the outer plate 2 to form a wall flow, which strengthens the heat exchange intensity in the air supply cavity, and finally flows out through the air film hole 5, and forms a cold air cover on the outside of the outer plate 2 to isolate the high-temperature mainstream; the double-wall internal air supply channel is divided into small sub-cavity air supply areas (i.e., air supply cavities) by the baffle plate 3, and the air film hole 5 is arranged on the outer plate 2 corresponding to each sub-cavity air supply area. The sub-cavity air supply can realize flow control of each air film hole 5 and enhance heat exchange; the double-wall cooling structure prevents the migration of cold air in the air supply channel, and at the same time, utilizes the outflow of the air film hole 5 to enhance the low heat exchange area between the impact holes 4, thereby enhancing the overall cooling efficiency.

[0024] In this embodiment, the air film holes 5 on the outer plate 2 are of a multi-row structure, and adjacent rows of air film holes 5 are arranged in a staggered or sequential order; the impact holes 4 on the inner plate 1 are of a multi-row structure, and adjacent rows of impact holes 4 are arranged in a staggered or sequential order, and the thickness of the outer plate 2 ranges from 1 to 2.5 times the diameter of the air film hole 5, and the angle between the central axis of each air film hole 5 and the tangent of the outer plate 2 where the air film hole 5 is located ranges from 20 to 160 degrees.

[0025] In this embodiment, the height of the air supply channel is 0.5 to 2.5 times the diameter of the air film hole 5, the thickness of the inner layer plate 1 is 0.5 to 1.5 times the diameter of the air film hole 5, the tangential angle between the center axis of the impact hole 4 and the wall of the inner layer plate 1 where the impact hole 4 is located is 90 degrees, and the diameter of the impact hole 45 is in the range of 0.5 to 2 times the diameter of the air film hole 5.

[0026] It should be noted that the wall thickness of the outer plate 2, the height of the internal air supply channel and the wall thickness of the inner plate 1 in this embodiment can be adjusted accordingly according to the heat load on the gas side and the structural strength, and the arrangement and density of the air film holes 5 and the impact holes 4, the aperture of the impact holes 4 and the thickness of the baffle 3 can also be adaptively adjusted according to the heat load on the gas side. For example, the thinner the baffle 3, the better the heat exchange effect, but the thickness of the baffle 36 is related to the strength and should be adaptively designed according to the heat load on the gas side.

[0027] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A novel small channel double-wall cooling structure with divided cavity air supply, characterized in that: It comprises an inner plate (1) and an outer plate (2) sleeved on the outer periphery of the inner plate (1), an air supply channel for airflow is arranged between the inner plate (1) and the outer plate (2); a plurality of baffles (3) are arranged between the inner plate (1) and the outer plate (2), and the plurality of baffles (3) are used to divide the air supply channel into a plurality of independent air supply cavities; an impact hole (4) penetrating the wall thickness of the inner plate (1) is provided on the inner plate (1) corresponding to each air supply cavity, and an air film hole (5) penetrating the wall thickness of the outer plate (2) is provided on the outer plate (2) corresponding to each air supply cavity.

2. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The air film holes (5) on the outer plate (2) are of a multi-row structure, and adjacent rows of air film holes (5) are arranged in a staggered or sequential manner; the impact holes (4) on the inner plate (1) are of a multi-row structure, and adjacent rows of impact holes (4) are arranged in a staggered or sequential manner.

3. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The thickness of the outer layer plate (2) is in the range of 1 to 2.5 times the diameter of the air film hole (5).

4. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The included angle between the central axis of each air film hole (5) and the tangent direction of the outer plate (2) where the air film hole (5) is located is in the range of 20 to 160 degrees.

5. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The height of the air supply channel is 0.5 to 2.5 times the diameter of the air film hole (5).

6. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The thickness of the inner layer plate (1) is 0.5 to 1.5 times the diameter of the air film hole (5).

7. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The tangential angle between the central axis of the impact hole (4) and the wall surface of the inner plate (1) where the impact hole (4) is located is 90 degrees.

8. The novel small channel double-wall cooling structure with divided-cavity air supply according to claim 1 is characterized in that: The diameter of the impact hole (4) 5 is in the range of 0.5 to 2 times the diameter of the air film hole (5).

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