Truss type double wall heat insulation device for engine combustion chamber and cold air film forming method

Abstract

The present invention relates to a truss-type double-wall heat insulation device for an engine combustion chamber, comprising a film hole plate layer, an impact hole plate layer and a sandwich Pozi truss for forming the inner wall of the combustion chamber cylinder, the sandwich Pozi truss is composed of four truss rods, the midpoints of the four truss rods intersect each other to form a central intersection, and the two ends of the four truss rods are respectively connected to the impact hole plate and the film hole layer; the film hole matching the sandwich Pozi truss is arranged on the film hole plate; the impact hole matching the sandwich Pozi truss is arranged on the impact hole plate, and the present invention also provides a method for forming a cold air film by the device, wherein the film holes and the impact holes are matched to form four longitudinal cooling vortex systems extending in the airflow direction between the film hole plate layer and the impact hole plate layer, and a film cold air heat insulation layer is formed on the outer wall surface of the film hole plate. The present invention has a simple structure and high strength, improves the engine operating temperature and service life, and also improves the strength.

Description

Technical Field

[0001] The invention belongs to the field of gas turbine engines, and in particular relates to a double-wall heat insulation screen structure of a truss sandwich structure and a cold air film forming method. Background Art

[0002] Several combustion chamber heat shields have been disclosed before, including a porous corrugated plate combustion chamber heat shield (US005465572A), the elasticity of which can effectively prevent the influence caused by the thermal deformation of the vibrating core cylinder, and the cooling jet of the discrete air film holes on the corrugated plate is used to perform air film cooling on the high-temperature gas side of the heat shield. However, it is precisely because of the corrugated structure that the cooling air film jet is difficult to cover the entire surface, so that the local wall temperature is too high, and it is impossible to form effective air film coverage and heat exchange; another is a divergent cooling heat shield structure with spoiler columns (US 20140096527A1), which forms an air film coverage on the wall surface through divergent cooling to block direct contact with high-temperature gas. At the same time, the spoiler column structure on the cold air side wall of the heat shield can disturb and mix the cold air, strengthen convective heat exchange, and allow the cold air to take away more heat and reduce the wall temperature. However, the simple divergent cooling form makes it difficult for the spoiler column to play a better role, and the cooling flow mixing is not strong enough to improve its cooling efficiency.

[0003] Based on the above experience, combined with traditional air film cooling, impingement cooling and other methods, the patent (CN103968418A) discloses a double-wall heat insulation screen for combustion chambers. This structure includes a wall with air film holes close to the gas side, a wall with impingement holes close to the cold air side, and a trapezoidal reinforcement frame between the air film orifice plate and the impingement orifice plate, thus forming a composite cooling form of impingement cooling on the cold air side, internal convection heat exchange and gas gas film covering. This structure can remove the incoming heat through convection heat exchange, improve the utilization rate of cold air, and has good mechanical properties. However, this structure does not take into account the flow resistance brought by the trapezoidal reinforcement frame during the internal convection heat exchange process.

[0004] With the development of advanced high-performance gas turbine engines, the temperature of the gas flowing through the combustion chamber continues to increase. In addition, as the air flow required for mainstream combustion increases, the air flow used for cooling decreases. Therefore, a heat shield structure with a more reasonable structure and cooling capacity must be applied to increase the life of the engine. Summary of the invention

[0005] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a truss-type double-wall insulation device and a cold air film forming method for an engine combustion chamber which has a simple structure, greatly reduces the engine operating temperature, increases the strength, and improves the service life and performance of the engine.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a truss-type double-wall heat insulation device for an engine combustion chamber, comprising an air film hole plate layer for constituting the inner wall of the combustion chamber cylinder and an impact hole plate layer on the outer side of the air film hole plate layer, the inner side of the air film hole plate layer is the main gas duct of the combustion chamber, and the impact hole plate layer and the outer wall surface of the combustion chamber together constitute the cold air outer duct; a matrix-arranged sandwich Pozi truss is provided in the cavity between the air film hole plate layer and the impact hole plate layer; the air film hole plate layer, the impact hole plate layer and the sandwich Pozi truss together constitute a double-wall heat insulation screen;

[0007] The sandwich Pozi truss is composed of four truss rods, the midpoints of the four truss rods cross each other to form a central intersection, and the two ends of the four truss rods are respectively connected to the impact orifice plate and the air film hole layer; the air film hole matching the sandwich Pozi truss is arranged on the air film hole plate; the impact hole matching the sandwich Pozi truss is arranged on the impact hole plate, and the air film holes and impact holes are used to form four longitudinal cooling vortex systems extending in the air flow direction between the air film hole plate layer and the impact hole plate layer and to form an air film cold air insulation layer on the outer wall surface of the air film hole plate.

[0008] Furthermore, among the four connection points of the four truss rods on the air film hole plate, two connection points on the same circumferential line are located in front of the central intersection along the air flow direction, and the remaining two connection points are located in the rear of the central intersection along the air flow direction. The air film holes are arranged between the four connection points, and the air film holes are single-row holes or double-row holes consisting of at least three holes along the circumferential direction.

[0009] Furthermore, among the four connection points of the four truss rods on the impact hole plate, two connection points on the same circumferential line are located in front of the central intersection along the airflow direction, and the remaining two connection points are located in the rear of the central intersection along the airflow direction. The impact holes are arranged between the four connection points, and the impact holes are single-row holes or double-row holes consisting of at least three holes along the circumferential direction.

[0010] Further, the matrix arrangement of the plurality of sandwich Pozi trusses is specifically as follows: Sx is the axial arrangement spacing of the sandwich Pozi trusses, Sz is the circumferential arrangement spacing of the sandwich Pozi trusses, H is the distance between the air film orifice plate and the impact orifice plate, d is the diameter of the sandwich Pozi trusses, and the axial and circumferential arrangement distances of the two sandwich Pozi trusses are:

[0011] H≥S x ≥2d, H≥S z ≥ 2 days;

[0012] The sandwich Pozigzag trusses are arranged in a continuous extension according to a set distance in the axial direction of the cavity between the air film orifice plate and the impact orifice plate, and are arranged in a staggered extension according to a set distance in the circumferential direction.

[0013] Furthermore, the air film hole is a through hole with a normal angle of 20 to 60° with the air film hole plate, and the diameter of the air film hole is 0.3 to 10 mm.

[0014] Furthermore, the ratio of the diameter d of the sandwich truss to the distance H between the impact orifice plate and the air film orifice plate varies in the range of 0.05 to 0.25.

[0015] Furthermore, the impact hole is a normal through hole of the impact plate; the diameter of the impact hole is 1 to 2 mm.

[0016] Furthermore, the wall normal angle between the sandwich Pozi truss and the air film orifice plate is θ, and θ is 30-60°; the length of the truss rod constituting the sandwich Pozi truss is l, and H is the distance between the air film orifice plate (1) and the impact orifice plate, then l=H / cosθ.

[0017] The present invention also provides a method for forming an air film on an air film orifice plate of a truss-type double-wall heat insulation device for an engine combustion chamber, the steps of which are as follows:

[0018] A portion of the cooling air flow in the cold air duct is perpendicular to the impact jet of the impact orifice plate and enters the cavity between the air film orifice plate and the impact orifice plate through the impact holes on the impact orifice plate;

[0019] A part of the impact jet entering the cavity between the air film orifice plate and the impact orifice plate is an impact jet that directly impacts and cools the inner wall surface of the air film orifice plate to form an impact cooling airflow, and another part impacts the sandwich Pozi truss and collides with the surface of the sandwich Pozi truss to form a bypass flow around the sandwich Pozi truss.

[0020] A part of the circumferential flow descending around the sandwich Pozi truss sweeps and obliquely impacts the inner wall surface of the air film orifice plate, and another part of the circumferential flow mixes with the main airflow between the air film orifice plate and the impact orifice plate, forming a longitudinal cooling vortex system filling the cavities on both sides of the sandwich Pozi truss along the airflow direction, and taking the central intersection of the sandwich Pozi truss as the midpoint, two parallel longitudinal cooling vortex systems are formed on both sides of the sandwich Pozi truss, thereby strengthening the cooling between the air film orifice plate and the impact orifice plate;

[0021] The circumferential flow that sweeps and obliquely impacts the inner wall of the air film orifice plate enters the air film holes of the air film orifice plate to form an air jet, and the air jet flowing out from the outer wall of the air film orifice plate forms an air film cold air insulation layer, thereby reducing the heat load of the mainstream high-temperature gas in the main gas duct of the combustion chamber on the wall of the combustion chamber.

[0022] The beneficial effects of the present invention are as follows: the truss-type double-wall heat insulation device for the engine combustion chamber provided by the present invention comprises a gas-side air film orifice plate, a cold-air side impact orifice plate and a cross-shaped truss array structure connecting the air film orifice plate and the impact orifice plate, the impact orifice plate and the outer wall of the combustion chamber form a cold-air duct, the air film orifice plate is the inner wall of the cylinder of the combustion chamber, and is in direct contact with the mainstream gas, the impact orifice plate and the air film orifice plate form a convection heat exchange channel, and accelerate the heat exchange through four longitudinal rotating vortices in the convection channel, take away a large amount of heat between the impact orifice plate and the air film orifice plate, quickly reduce the temperature between the impact orifice plate and the air film orifice plate, and at the same time, accelerate the reduction of the cooling pressure on the air film orifice plate, greatly improve the service life of the engine; the composite cooling method of impact-air film can also be used to form an air film covering on the gas side of the heat insulation screen to block the direct contact between the gas and the engine load-bearing structure; at the same time, the sandwich cross-shaped truss structure can effectively fix the impact orifice plate and the air film orifice plate, enhance its structural performance, improve the service life and reliability of the combustion chamber, and have good mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the double-wall heat insulation screen of the three-rod Pozidriv truss of the present invention;

[0024] Figure 2 The three-bar Pozidriv truss unit and its array structure diagram of the present invention;

[0025] Figure 3 It is a schematic diagram of an axial section of a double-wall heat insulation screen of a three-bar Pozidriv truss according to the present invention in the airflow direction;

[0026] Figure 4 It is a schematic diagram of the local coupling effect of the double-wall heat insulation screen structure of the three-bar Pozi truss of the present invention;

[0027] Figure 5 It is a schematic cross-sectional view of the double-wall heat insulation screen of the three-rod Pozidriv truss of the present invention in the airflow direction.

[0028] In the figure, 1. air film orifice plate, 2. impact orifice plate, 3. sandwich M-shaped truss, 4. outer wall of the combustion chamber, 5. air film hole, 6. impact hole, 7. cold air outer duct, 8. mainstream gas duct. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] Example 1: Figure 1 , Figure 2 , Figure 3As shown, a truss-type double-wall heat insulation device for an engine combustion chamber comprises an air film plate layer 1 for forming the inner wall of the combustion chamber cylinder and an impact plate layer 2 on the outer side of the air film plate layer, the inner side of the air film plate layer 1 is a combustion chamber main gas duct (8), and the impact plate layer 2 and the outer wall surface 4 of the combustion chamber together form a cold air outer duct 7; a matrix-arranged sandwich Pozi truss 3 is arranged in the cavity between the air film plate layer 1 and the impact plate layer 2; the air film plate layer 1, the impact plate layer 2 and the sandwich Pozi truss 3 together form a double-wall heat insulation screen;

[0031] The sandwich Pozigzag truss 3 is composed of four truss rods, the midpoints of the four truss rods cross each other to form a central intersection, and the two ends of the four truss rods are respectively connected to the impact orifice plate 2 and the air film hole layer 1; an air film hole 5 matching the sandwich Pozigzag truss 3 is arranged on the air film hole plate 1; an impact hole 6 matching the sandwich Pozigzag truss 3 is arranged on the impact orifice plate 2, and the air film holes 5 and the impact holes 6 are used to form four longitudinal cooling vortex systems extending in the air flow direction between the air film hole plate layer 1 and the impact hole plate layer 2 and to form an air film cold air insulation layer on the outer wall surface of the air film hole plate 1.

[0032] Among the four connection points of the four truss rods on the air film orifice plate 1, two connection points on the same circumferential line are located in front of the central intersection along the airflow direction, and the remaining two connection points are located in the rear of the central intersection along the airflow direction. The air film holes 5 are arranged between the four connection points, and the air film holes 5 are single-row holes or double-row holes composed of at least three holes along the circumferential direction. The air film holes 5 are through holes with a normal angle of 20 to 60 degrees with the air film orifice plate 1, and the diameter of the air film holes 5 is 0.3 to 10 mm.

[0033] Among the four connection points of the four truss rods on the impact orifice plate 2, two connection points on the same circumferential line are located in front of the central intersection along the airflow direction, and the remaining two connection points are located in the rear of the central intersection along the airflow direction. The impact holes 6 are arranged between the four connection points, and the impact holes 6 are single-row holes or double-row holes composed of at least three holes along the circumferential direction. The impact holes 6 are normal through holes of the impact orifice plate 2; the diameter of the impact holes 6 is 1 to 2 mm.

[0034] The matrix arrangement of the multiple sandwich Pozi trusses 3 is specifically as follows: Sx is the axial arrangement spacing of the sandwich Pozi trusses 3, Sz is the circumferential arrangement spacing of the sandwich Pozi trusses 3, H is the distance between the air film orifice plate 1 and the impact orifice plate 2, d is the diameter of the sandwich Pozi trusses 3, and the axial and circumferential arrangement distances of the two sandwich Pozi trusses 3 are:

[0035] H≥S x ≥2d, H≥S z ≥ 2 days;

[0036] The sandwich Pozi truss 3 is continuously extended and arranged in the axial direction of the cavity between the air film orifice plate 1 and the impact orifice plate 2 according to the set distance, and is staggered and extended in the circumferential direction according to the set distance. The ratio of the diameter d of the sandwich Pozi truss 3 to the spacing H between the impact orifice plate 2 and the air film orifice plate 1 varies in the range of: 0.05 to 0.25. The wall normal angle between the sandwich Pozi truss 3 and the air film orifice plate 1 is θ, and θ is 30-60°; the length of the truss rod constituting the sandwich Pozi truss 3 is l, H is the distance between the air film orifice plate 1 and the impact orifice plate 2, then l = H / cosθ.

[0037] This embodiment is a double-wall heat insulation screen for a combustion chamber, comprising an air film orifice plate 1, an impact orifice plate 2, and a sandwich Pozi truss 3. The gas-side air film orifice plate 1 constitutes the inner wall of the combustion chamber cylinder, and the inner side is the main gas duct 8 of the combustion chamber, that is, the flow channel of the mainstream high-temperature gas A in the combustion chamber; the cold-gas side impact orifice plate 2 and the outer wall surface 4 together constitute the cold-gas duct 7; a sandwich Pozi truss 3 is arranged between the impact orifice plate 2 and the air film orifice plate 1, together forming a double-wall heat insulation screen; since the sandwich Pozi truss 3 is a typical lattice structure, it is fixed to the air film orifice plate 1 and the impact orifice plate 2 by point contact welding, forming a structurally complete integrated structure.

[0038] Figure 2 The arrangement of the sandwich V-shaped truss 3 array structure is shown in FIG. The sandwich V-shaped truss 3 is composed of four truss rods intersecting at one point. Generally, the four truss rods have the same inclination angle, length and diameter, forming a regular polyhedral truss structure. The vertices of this polyhedral truss unit are connected to the impact hole plate, and the spacing Sz between adjacent truss rods in the axial X direction and the spacing Sx between two adjacent rows of sandwich V-shaped trusses 3 in the circumferential Z direction can be non-constant values.

[0039] As the angle changes, the length of the truss rod changes, the heat conductivity changes, and the flow resistance to the fluid also changes; the increase or decrease in diameter affects the solid ratio and the change in the contact area with the fluid, and the diameter affects the change in flow resistance and heat transfer performance. The density of the array structure can be controlled by the spacing of the sandwich cross trusses 3. When the spacing is a constant value, the polyhedral truss array is a regular structure. When the form of the array structure changes, the disturbance mixing of the impact jet also changes, resulting in changes in the cooling efficiency of the internal cooling structure and changes in the amount of cold air used.

[0040] Example 2: Figure 4 , Figure 5 As shown, the present invention also provides a method for forming an air film on an air film orifice plate of a truss-type double-wall heat insulation device for an engine combustion chamber, the steps of which are as follows:

[0041] Part of the cooling air flow B in the cold air duct 7 is perpendicular to the impact jet C1 of the impact orifice plate 2, and enters the cavity between the air film orifice plate 1 and the impact orifice plate 2 through the impact hole 6 on the impact orifice plate 2;

[0042] The impact jet C1 entering the cavity between the air film orifice plate 1 and the impact orifice plate 2 is a part of the impact jet that directly impacts and cools the inner wall surface of the air film orifice plate 1, forming an impact cooling airflow C3, and the other part impacts the sandwich Pozi truss 3 and collides with the surface of the sandwich Pozi truss 3 to form a bypass flow C2 around the sandwich Pozi truss 3.

[0043] A part of the circumferential flow C2 descending around the sandwich Pozi truss 3 sweeps and obliquely impacts the inner wall surface of the air film orifice plate 1, and the other part of the circumferential flow C2 is mixed with the main airflow between the air film orifice plate 1 and the impact orifice plate 2, and a longitudinal cooling vortex system C4 filling the cavities on both sides of the sandwich Pozi truss 3 is formed on both sides of the Pozi truss 3 along the airflow direction, and two parallel longitudinal cooling vortex systems C4 are formed on both sides of the sandwich Pozi truss 3 with the central intersection of the sandwich Pozi truss 3 as the midpoint, so as to strengthen the cooling between the air film orifice plate 1 and the impact orifice plate 2;

[0044] The circumferential flow C2 that sweeps and obliquely impacts the inner wall surface of the air film orifice plate 1 enters the air film hole 5 of the air film orifice plate to form an air flow jet C5. The air flow jet C5 flowing out from the outer wall surface of the air film orifice plate 1 forms an air film cold air insulation layer, reducing the heat load of the mainstream high-temperature fuel gas A in the main fuel gas duct 8 of the combustion chamber on the combustion chamber wall.

[0045] Figure 5 It is shown that four longitudinal cooling vortex systems C4 are formed on both sides of the sandwich truss 3 along the air flow direction. The four longitudinal cooling vortex systems C4 extend in the air flow direction and quickly bring out the heat in the cavity between the film orifice plate 1 and the impact orifice plate 2. At the same time, the jet flowing out of the film hole 5 from the outer wall of the film orifice plate 1 forms a cold air insulation layer. The two cooperate to realize the cooling function of the combustion chamber and improve the performance and life of the engine.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A truss-type double-wall heat insulation device for an engine combustion chamber, characterized in that: It comprises an air film plate layer (1) for forming the inner wall of a combustion chamber cylinder and an impact plate layer (2) outside the air film plate layer (1), the inner side of the air film plate layer (1) is a main gas duct (8) of the combustion chamber, and the impact plate layer (2) and the outer wall surface (4) of the combustion chamber together form a cold air outer duct (7); a matrix-arranged sandwich Pozi truss (3) is provided in the cavity between the air film plate layer (1) and the impact plate layer (2); the air film plate layer (1), the impact plate layer (2) and the sandwich Pozi truss (3) together form a double-wall heat insulation screen; The sandwich Pozi truss (3) is composed of four truss rods, the midpoints of the four truss rods intersect with each other to form a central intersection, and the two ends of the four truss rods are respectively connected to the impact hole plate layer (2) and the air film hole plate layer (1); the air film hole (5) cooperating with the sandwich Pozi truss (3) is arranged on the air film hole plate layer (1); the impact hole (6) cooperating with the sandwich Pozi truss (3) is arranged on the impact hole plate layer (2), and the air film hole (5) and the impact hole (6) are used to form four longitudinal cooling vortex systems extending in the air flow direction between the air film hole plate layer (1) and the impact hole plate layer (2) and to form an air film cold air insulation layer on the outer wall surface of the air film hole plate layer (1).

2. The truss-type double-wall heat insulation device for an engine combustion chamber according to claim 1, characterized in that: Among the four connection points of the four truss rods on the air film hole plate layer (1), two connection points on the same circumferential line are located in front of the central intersection along the air flow direction, and the remaining two connection points are located in the rear of the central intersection along the air flow direction. The air film holes (5) are arranged between the four connection points, and the air film holes (5) are single-row holes or double-row holes composed of at least three holes along the circumferential direction.

3. The truss type double-wall heat insulation device for an engine combustion chamber according to claim 1 or 2, characterized in that: Among the four connection points of the four truss rods on the impact hole plate layer (2), two connection points on the same circumferential line are located in front of the central intersection along the airflow direction, and the remaining two connection points are located in the rear of the central intersection along the airflow direction. The impact holes (6) are arranged between the four connection points, and the impact holes (6) are single-row holes or double-row holes consisting of at least three holes along the circumferential direction.

4. The truss type double-wall heat insulation device for an engine combustion chamber according to claim 1, characterized in that: The matrix arrangement of the plurality of sandwich trusses (3) is specifically as follows: x S is the axial arrangement spacing of the sandwich truss (3), z is the circumferential arrangement spacing of the sandwich Pozi trusses (3), H is the distance between the air film hole plate layer (1) and the impact hole plate layer (2), d is the diameter of the sandwich Pozi trusses (3), and the axial and circumferential arrangement distances of the two sandwich Pozi trusses (3) are: H≥S x ≥2d、H≥S z ≥2d; The sandwich Pozigzag trusses (3) are arranged in a continuous extension according to a set distance in the axial direction of the cavity between the air film hole plate layer (1) and the impact hole plate layer (2), and are arranged in a staggered extension according to a set distance in the circumferential direction.

5. The truss type double wall heat insulation device for engine combustion chamber according to claim 2, characterized in that: The air film hole (5) is a through hole with a normal angle of 20 to 60 degrees with the air film hole plate layer (1), and the diameter of the air film hole (5) is 0.3 to 10 mm.

6. The truss type double wall heat insulation device for an engine combustion chamber according to claim 1, characterized in that: The ratio of the diameter d of the sandwich truss (3) to the spacing H between the impact hole plate layer (2) and the air film hole plate layer (1) varies in the range of 0.05 to 0.

25.

7. The truss type double wall heat insulation device for an engine combustion chamber as claimed in claim 3, characterized in that: The impact hole (6) is a normal through hole of the impact hole plate layer (2); the diameter of the impact hole (6) is 1 to 2 mm.

8. The truss-type double-wall heat insulation device for an engine combustion chamber according to any one of claims 4 to 7, characterized in that: The normal angle between the sandwich truss (3) and the wall of the air film hole plate layer (1) is θ, and θ is 30-60°; the length of the truss rod constituting the sandwich truss (3) is l , H is the distance between the air film orifice plate layer (1) and the impact orifice plate layer (2), then l=H / cos θ.

9. The method for forming a cold air film on an air film orifice plate of a truss-type double-wall heat insulation device for an engine combustion chamber according to claim 8, characterized in that: In the cold air duct (7), a portion of the cooling air flow (B) perpendicular to the impact hole plate layer (2) is an impact jet (C1), and the impact jet (C1) enters the cavity between the air film hole plate layer (1) and the impact hole plate layer (2) through the impact holes (6) on the impact hole plate layer (2); A part of the impact jet (C1) entering the cavity between the air film hole plate layer (1) and the impact hole plate layer (2) is an impact jet that directly impacts and cools the inner wall surface of the air film hole plate layer (1) to form an impact cooling airflow (C3), and another part impacts the sandwich Pozi truss (3) and collides with the surface of the sandwich Pozi truss (3) to form a bypass flow (C2) around the sandwich Pozi truss (3). A portion of the circumferential flow (C2) descending around the sandwich Pozigzag truss (3) sweeps and obliquely impacts the inner wall surface of the air film hole plate layer (1), and another portion of the circumferential flow (C2) is mixed with the main airflow between the air film hole plate layer (1) and the impact hole plate layer (2), forming a longitudinal cooling vortex system (C4) filling the cavities on both sides of the sandwich Pozigzag truss (3) on both sides of the Pozigzag truss (3) along the airflow direction, and with the central intersection of the sandwich Pozigzag truss (3) as the midpoint, two parallel longitudinal cooling vortex systems (C4) are formed on both sides of the sandwich Pozigzag truss (3), thereby strengthening the cooling between the air film hole plate layer (1) and the impact hole plate layer (2); The bypass flow (C2) that sweeps and obliquely impacts the inner wall surface of the air film hole plate layer (1) enters the air film hole (5) of the air film hole plate to form an air flow jet (C5), and the air flow jet (C5) flowing out from the outer wall surface of the air film hole plate layer (1) forms an air film cold air insulation layer, thereby reducing the heat load of the mainstream high-temperature fuel gas (A) in the main fuel gas duct (8) of the combustion chamber on the combustion chamber wall surface.

Images