Novel gap-communicated small-channel double-wall cooling structure

Abstract

The invention relates to the technical field of cooling of turbine blades of gas turbines, and discloses a novel small-channel double-wall cooling structure with communicated gaps, and flow baffles are designed in air supply channels, so that the phenomenon of cold air migration in internal channels of impact divergence double-wall blades can be effectively improved; the gaps are formed in the flow baffles to supply cold air to the air film holes, the cold air impacts on the inner wall face of the outer layer plate through the impact holes and strengthens heat exchange, impact jet flow impacts on the inner wall face to form wall face flow, then the wall face flow passes through the gaps, the heat exchange intensity of the gap areas is strengthened, and finally the cold air flows out through the air film holes. Cold air covering is formed on the outer side of the outer layer plate to isolate high-temperature main flow. And the cold air migration phenomenon in an internal channel of the double-layer-wall blade is reduced, meanwhile, the surface average comprehensive cooling efficiency can be improved, and the uniformity of blade temperature distribution is improved.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine turbine blade cooling, and discloses a new type of small channel double-layer wall cooling structure with gap communication. 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 gap communication, which can effectively improve the cold air migration phenomenon in the internal channel of the impact divergent double-wall blade, and can improve the surface average comprehensive cooling efficiency 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 double-wall cooling structure with small channels connected by gaps comprises an inner plate and an outer plate sleeved on the outer periphery of the inner plate, an air supply channel for air circulation is arranged between the inner plate and the outer plate; 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; a plurality of baffles are arranged between the inner plate and the outer plate, and a gap for air circulation is arranged between two adjacent baffles.

[0008] Furthermore, the air film holes and the impact holes are arranged in N rows, the spacing between each row of holes is 1 to 2.5 times the diameter of the air film holes, adjacent rows of air film holes are arranged in a staggered or sequential manner, and adjacent rows of impact holes are arranged in a staggered or sequential manner.

[0009] Furthermore, the baffles are arranged in multiple rows, and baffles in the same row are located between impact holes in two adjacent rows.

[0010] Furthermore, the gap width between two adjacent baffle plates in the same row of baffle plates is 0.5 to 1.5 times the hole spacing of the same exhaust membrane.

[0011] Furthermore, an air film hole is provided at a position of the outer layer plate corresponding to the gap between two adjacent baffle plates in the same row of baffle plates.

[0012] Furthermore, the thickness of the baffle along the arrangement direction of the impact hole row is in the range of 0.1 to 2.5 times the diameter of the air film hole.

[0013] 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.

[0014] Furthermore, the height of the air supply channel is 0.5 to 2.5 times the diameter of the air film hole.

[0015] Furthermore, the thickness of the inner layer plate is 0.5 to 1.5 times the diameter of the air film hole.

[0016] Furthermore, the diameter of the impact hole is in the range of 0.5 to 2 times of the diameter of the air film hole, and 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.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can effectively improve the cold air migration phenomenon in the internal channel of the impact divergent double-wall blade by designing a baffle in the air supply channel; by setting a gap on the baffle to supply cold air to the air film holes, the heat exchange intensity of the gap area is enhanced, and while reducing the cold air migration phenomenon in the internal channel of the double-wall blade, it can also improve the surface average comprehensive cooling efficiency and improve the uniformity of the blade temperature distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a novel double-wall cooling structure with small channels connected by gaps in an embodiment;

[0019] Figure 2 Schematic diagram of the positional relationship among the air film hole, the impact hole and the baffle plate in a top view in the embodiment;

[0020] Figure 3 This is a cloud diagram of the comprehensive cooling efficiency of the external air film orifice plate of a typical impingement-divergence double-wall cooling system;

[0021] Figure 4 This is a cloud diagram of the comprehensive cooling efficiency of the outer plate of the small channel double-wall cooling structure in this embodiment;

[0022] Among them, 1. Inner plate; 2. Outer plate; 3. Baffle; 4. Impact hole; 5. Air film hole. DETAILED DESCRIPTION

[0023] 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.

[0024] Example

[0025] See also Figure 1 and Figure 2 A new type of small channel double-wall cooling structure with gap communication, 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; 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; a plurality of baffles 3 are arranged between the inner plate 1 and the outer plate 2, and a gap for air flow to pass through is arranged between two adjacent baffles 3.

[0026] In this embodiment, by designing a baffle 3 in the air supply channel, the cold air migration phenomenon in the internal channel of the impact divergent double-wall blade can be effectively improved, and a gap is set on the baffle 3 to supply cold air to the air film hole 5. The cold air impacts the inner wall surface of the outer layer plate 2 from the impact hole 4 and strengthens the heat exchange. The impact jet impacts the inner wall surface to form a wall flow and then passes through the gap, which strengthens the heat exchange intensity of the gap area. Finally, it flows out through the air film hole 5, forming a cold air cover on the outside of the outer layer plate 2 to isolate the high-temperature mainstream. This double-wall cooling structure can reduce the cold air migration phenomenon in the internal channel of the double-wall blade, and can also improve the surface average comprehensive cooling efficiency and improve the uniformity of the blade temperature distribution.

[0027] In this embodiment, the air film holes 5 and the impact holes 4 are arranged in N rows, and the hole spacing of each row is 1 to 2.5 times the diameter of the air film holes 5. Adjacent rows of air film holes 5 are arranged in a staggered or sequential manner, and adjacent rows of impact holes 4 are arranged in a staggered or sequential manner. The baffle plates 3 are a multi-row structure, and the same row of baffle plates 3 is located between two adjacent rows of impact holes 4.

[0028] In this embodiment, an air film hole 5 is provided at a position of the outer plate 2 corresponding to the gap between two adjacent baffles 3 in the same row of baffles 3. This is achieved by arranging the air film hole 5 just above the gap area, thereby preventing the migration of cold air and utilizing 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.

[0029] In this embodiment, the gap width between two adjacent baffle plates 3 in the same row of baffle plates 3 is 0.5 to 1.5 times the hole spacing of the same exhaust film hole 5. The baffle plates 3 are arranged along the direction of the impact hole 4 row (such as Figure 2 The thickness in the X-axis direction) ranges from 0.1 to 2.5 times the aperture of the air film hole 5. 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. The height of the air supply channel is 0.5 to 2.5 times the aperture of the air film hole 5. The thickness of the inner plate 1 is 0.5 to 1.5 times the aperture of the air film hole 5. The aperture of the impact hole 4 ranges from 0.5 to 2 times the aperture of the air film hole 5, and the tangent angle between the central axis of the impact hole 4 and the wall of the inner plate 1 where the impact hole 4 is located is 90 degrees.

[0030] It should be noted that the wall thickness of the outer plate 2, the height of the internal air supply channel, the wall thickness of the inner plate 1 and the gap of the baffle 3 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 width of the baffle 3 can also be adaptively adjusted according to the heat load on the gas side.

[0031] like Figure 3 and Figure 4 As shown, this embodiment also obtains the comprehensive cooling efficiency cloud diagram of the external orifice plate of the typical impact divergent double-wall cooling through numerical simulation ( Figure 3 ) and the comprehensive cooling efficiency cloud diagram of the outer plate 2 of the small channel double-wall cooling structure of the present invention ( Figure 4 ); The difference between these two structures is that the typical impingement divergent double-wall cooling does not have the baffle 3 structure in the small channel double-wall cooling. Figure 3 and Figure 4 The data corresponding to the middle color area represents the cooling efficiency (the higher the cooling efficiency, the better). By comparison, it can be seen that the small channel double-wall cooling structure of the present invention can significantly improve the cooling efficiency.

[0032] 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 new type of small channel double-wall cooling structure with gap connection, 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 air flow is arranged between the inner plate (1) and the outer plate (2); an impact hole (4) penetrating the wall thickness of the inner plate (1) is opened 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 opened on the outer plate (2) corresponding to each air supply cavity; a plurality of baffles (3) are arranged between the inner plate (1) and the outer plate (2), and a gap for air flow to pass is arranged between two adjacent baffles (3).

2. The novel double-wall cooling structure with small channels connected by gaps according to claim 1 is characterized in that: The air film holes (5) and the impact holes (4) are arranged in N rows, the spacing between each row of holes is 1 to 2.5 times the diameter of the air film holes (5), adjacent rows of air film holes (5) are arranged in a staggered or sequential manner, and adjacent rows of impact holes (4) are arranged in a staggered or sequential manner.

3. The novel double-wall cooling structure with small channels connected by gaps according to claim 2 is characterized in that: The baffle plates (3) are of a multi-row structure, and baffle plates (3) in the same row are located between impact holes (4) in two adjacent rows.

4. The novel double-wall cooling structure with small channels connected by gaps according to claim 3 is characterized in that: The gap width between two adjacent baffle plates (3) in the same row of baffle plates (3) is 0.5 to 1.5 times the hole spacing of the same exhaust film hole (5).

5. The novel double-wall cooling structure with small channels connected by gaps according to claim 3 is characterized in that: An air film hole (5) is provided at a position of the outer layer plate (2) corresponding to the gap between two adjacent baffle plates (3) in the same row of baffle plates (3).

6. The novel double-wall cooling structure with small channels connected by gaps according to any one of claims 1 to 5, characterized in that: The thickness of the baffle plate (3) along the direction of arrangement of the impact holes (4) is in the range of 0.1 to 2.5 times the diameter of the air film holes (5).

7. The novel double-wall cooling structure with small channels connected by gaps 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.

8. The novel double-wall cooling structure with small channels connected by gaps 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).

9. The novel double-wall cooling structure with small channels connected by gaps 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).

10. The novel double-wall cooling structure with small channels connected by gaps according to claim 1 is characterized in that: The diameter of the impact hole (4) is in the range of 0.5 to 2 times the diameter of the air film hole (5), and the tangential angle between the center 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.

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