阅读说明：本技术 用于发动机燃烧室的桁架式双层壁隔热装置及冷气膜形成方法 (Truss type double-wall heat insulation device for engine combustion chamber and cold air film forming method ) 是由 白晓辉 刘存良 刘海涌 傅松 王子文 于 2021-08-31 设计创作，主要内容包括：本发明涉及一种用于发动机燃烧室的桁架式双层壁隔热装置,包括用于构成燃烧室筒体内壁的气膜孔板层、冲击孔板层和夹芯米字桁架,夹芯米字桁架是由四根桁架杆组成,四根桁架杆的中点相互交叉形成一中心交叉点,四根桁架杆两端分别与冲击孔板和气膜孔层相连；在所述的气膜孔板上设置有与所述的夹芯米字桁架配合的气膜孔；在所述冲击孔板上设置有与所述的夹芯米字桁架配合的冲击孔,本发明还提供该装置形成冷气膜的方法,是由气膜孔和冲击孔配合在气膜孔板层和冲击孔板层之间形成延伸在气流流动方向上的四股纵向冷却涡系及在所述的气膜孔板的外壁面形成气膜冷气隔热层。本发明结构简单,强度高,提高了发动机运行温度和使用寿命,同时也提高了强度。(The invention relates to a truss type double-layer wall heat insulation device for an engine combustion chamber, which comprises an air film hole plate layer, an impact hole plate layer and a sandwich rice-shaped truss, wherein the air film hole plate layer, the impact hole plate layer and the sandwich rice-shaped truss are used for forming the inner wall of a combustion chamber cylinder body; the air film hole plate is provided with air film holes matched with the sandwich rice-shaped truss; the invention also provides a method for forming a cold air film by the device, wherein the air film holes and the impact holes are matched between an air film hole plate layer and an impact hole plate layer to form four longitudinal cooling vortices extending in the airflow flowing direction, and an air film cold air heat insulation layer is formed on the outer wall surface of the air film hole plate. The invention has simple structure and high strength, improves the running temperature of the engine, prolongs the service life of the engine and simultaneously improves the strength.)

1. The truss type double-wall heat insulation device for the engine combustion chamber is characterized by comprising a gas film pore plate layer (1) for forming the inner wall of a combustion chamber cylinder body and an impact pore plate layer (2) at the outer side of the gas film pore plate layer (1), wherein a combustion chamber main gas duct (8) is arranged at the inner side of the gas film pore plate layer (1), and the impact pore plate layer (2) and the outer wall surface (4) of the combustion chamber jointly form a cold air outer duct (7); sandwich rice-shaped trusses (3) arranged in a matrix are arranged in a cavity between the air film hole plate layer (1) and the impact hole plate layer (2); the air film hole plate layer (1), the impact hole plate layer (2) and the sandwich rice-shaped truss (3) form a double-wall heat shield together;

the sandwich rice-shaped truss (3) consists of four truss rods, the midpoints of the four truss rods are crossed with each other to form a central cross point, and two ends of the four truss rods are respectively connected with the impact orifice plate (2) and the air film orifice layer (1); the air film hole plate (1) is provided with an air film hole (5) matched with the sandwich rice-shaped truss (3); the impact orifice plate (2) is provided with impact orifices (6) matched with the sandwich rice-shaped truss (3), the air film orifices (5) and the impact orifices (6) are used for forming four longitudinal cooling vortices extending in the airflow flowing direction between the air film orifice plate layer (1) and the impact orifice plate layer (2) and forming an air film cold air heat insulation layer on the outer wall surface of the air film orifice plate (1).

2. A truss-type double-walled thermal insulation device for an engine combustion chamber as defined in claim 1, wherein of four connecting points of said four truss rods on the air film orifice plate (1), two connecting points on the same circumferential line are located at the front of said central cross point in the air flow direction, the remaining two connecting points are located at the rear of said central cross point in the air flow direction, said air film orifice (5) is disposed between the four connecting points, and the air film orifice (5) is a single row or a double row of at least three orifices in the circumferential direction.

3. A truss-type double-walled insulation apparatus for an engine combustion chamber as defined in claim 1 or 2 wherein, of the four connecting points of the four truss rods on the impingement orifice plate (2), two connecting points on the same circumferential line are located forward of the central intersection in the direction of air flow, the remaining two connecting points are located rearward of the central intersection in the direction of air flow, the impingement orifice (6) is disposed between the four connecting points, and the impingement orifice (6) is a single row or a double row of at least three orifices in the circumferential direction.

4. A trussed double-walled thermal insulation apparatus for an engine combustor according to claim 1, wherein the matrix arrangement of the plurality of sandwich core trusses (3) is embodied as: use Sx to arrange the interval for pressing from both sides core rice word truss (3) axial, Sz arranges the interval for pressing from both sides core rice word truss (3) circumference, H is the distance between gas film orifice plate (1) and impact orifice plate (2), d is the diameter of pressing from both sides core rice word truss (3), then two liang of core rice word trusses (3) axial and circumferential distance that sets up do:

H≥S_x≥2d、H≥S_z≥2d；

the sandwich rice-shaped truss (3) is continuously extended and arranged according to a set distance in the axial direction of a cavity between the air film pore plate (1) and the impact pore plate (2), and is extended and arranged in the circumferential direction according to the set distance in a staggered manner.

5. The truss-type double-wall heat insulation device for the engine combustion chamber as claimed in claim 2, wherein the film holes (5) are through holes with an angle of 20-60 degrees with the normal direction of the film hole plate (1), and the diameter of the film holes (5) is 0.3-10 mm.

6. A trussed double-walled thermal insulation for engine combustion chamber according to claim 1 wherein the ratio of the diameter d of said sandwiched mitre truss (3) to the distance H between said impingement orifice plate (2) and said gas film orifice plate (1) varies within the range of: 0.05 to 0.25.

7. A trussed double-walled thermal insulation for engine combustion chamber according to claim 3 wherein said impingement holes (6) are normal through holes of the impingement orifice plate (2); the diameter of the impact hole (6) is 1-2 mm.

8. A trussed double-walled thermal insulation apparatus for an engine combustor according to any one of claims 4 to 7, wherein the wall normal angle of said sandwiched rice trusses (3) to said gas membrane perforated plate (1) is θ, θ being 30 to 60 °; the length of a truss rod forming the sandwich rice-shaped truss (3) is l, H is the distance between the air film pore plate (1) and the impact pore plate (2), and l is H/cos theta.

9. A method of forming a cold gas film on a gas film hole plate by a truss-like double-walled heat insulating apparatus for an engine combustion chamber as set forth in claims 1 to 8,

the part of the cooling air flow (B) in the cold air bypass (7) is perpendicular to an impact jet flow (C1) of the impact orifice plate (2) and enters a cavity between the air film orifice plate (1) and the impact orifice plate (2) through an impact orifice (6) on the impact orifice plate (2);

the impact jet flow (C1) entering the cavity between the air film pore plate (1) and the impact pore plate (2) is characterized in that one part of the impact jet flow (C1) is the impact jet flow which directly performs impact cooling on the inner wall surface of the air film pore plate (1) to form impact cooling air flow (C3), the other part of the impact jet flow impacts the sandwich rice-shaped truss (3) and collides with the surface of the sandwich rice-shaped truss (3) to form a circumferential flow (C2) surrounding the sandwich rice-shaped truss (3),

one part of the circumambient descending stream (C2) of the sandwich rice-shaped truss (3) sweeps and obliquely impacts the inner wall surface of the air film pore plate (1), the other part of the circumambient descending stream (C2) is mixed with the main air stream between the air film pore plate (1) and the impact pore plate (2), longitudinal cooling vortex systems (C4) which are filled with cavities at two sides of the sandwich rice-shaped truss (3) are formed at two sides of the rice-shaped truss (3) along the air stream flowing direction, the central cross point of the sandwich rice-shaped truss (3) is taken as a middle point, two parallel longitudinal cooling vortex systems (C4) are respectively formed at two sides of the sandwich rice-shaped truss (3), and the space between the air film pore plate (1) and the impact pore plate (2) is reinforced and cooled;

the circumferential flow (C2) which sweeps and obliquely impacts the inner wall surface of the gas film pore plate (1) enters the gas film hole (5) of the gas film pore plate to form an airflow jet (C5), and the airflow jet (C5) which flows out of the outer wall surface of the gas film pore plate (1) forms a gas film cold air heat insulation layer, so that the heat load of the main flow high-temperature gas (A) in the main gas duct (8) of the combustion chamber on the wall surface of the combustion chamber is reduced.

Technical Field

The invention belongs to the field of gas turbine engines, and particularly relates to a double-wall heat shield structure of a truss sandwich structure and a cold air film forming method.

Background

Several combustion chamber heat shields have been disclosed heretofore, including a porous corrugated plate combustion chamber heat shield (US005465572A) whose corrugated structure is flexible to effectively prevent the effects of thermal deformation of the vibrating core cylinder, and which is subjected to film cooling on the high temperature gas side of the heat shield by the cooling jets of discrete film holes in the corrugated plate. However, due to the corrugated structure, the cooling film jet is difficult to cover the whole surface, so that the local wall temperature is too high, and effective film covering and heat exchange cannot be formed; the other is for taking the heat shield structure of cooling of dispersing (US 20140096527A1) of turbulence post, and the cooling form through dispersing forms the air film cover at the wall, the direct contact of separation high temperature gas, and simultaneously, the turbulence post structure on the heat shield air conditioning lateral wall can carry out the disturbance to cold air and mix, and the heat convection is reinforceed to the heat transfer, makes cold air take away more heat and reduces the wall temperature. However, the simple divergent cooling mode is difficult to make the spoiler column perform better function, the cooling flow is not mixed strongly enough, and the cooling efficiency cannot be improved.

Based on the above experience, in combination with conventional film cooling, impingement cooling, etc., patent (CN103968418A) discloses a double-walled heat shield for a combustor. The structure comprises a wall surface which is close to a gas side and is provided with a gas film hole, a wall surface which is close to a cold air side and is provided with an impact hole, and a trapezoidal strengthening frame between the gas film hole plate and the impact hole plate, so that a compound cooling form of cold air side impact cooling, internal convection heat exchange and gas film measurement covering is formed. This kind of structure can take away the heat of afferent through convection heat transfer, improves the air conditioning utilization ratio, has better mechanical properties simultaneously, however, the flow resistance that trapezoidal strengthening frame brought in inside convection heat transfer's in-process is not considered to this structure.

With the development of advanced high performance gas turbine engines, the temperature of the combustion gases flowing through the combustor is constantly increasing. In addition, since the air flow rate for cooling is reduced as the air flow rate required for the main flow combustion increases, it is necessary to apply a heat shield structure having a more rational structure and a cooling capability to increase the life of the engine.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a truss type double-wall heat insulation device for an engine combustion chamber and a cold air film forming method, wherein the truss type double-wall heat insulation device has a simple structure, greatly reduces the running temperature of an engine, increases the strength and improves the service life and the performance of the engine.

In order to achieve the purpose, the invention adopts the technical scheme that: a truss type double-wall heat insulation device for an engine combustion chamber comprises an air film hole plate layer and an impact hole plate layer, wherein the air film hole plate layer is used for forming the inner wall of a combustion chamber cylinder body, the impact hole plate layer is arranged on the outer side of the air film hole plate layer, a main combustion gas duct of the combustion chamber is arranged on the inner side of the air film hole plate layer, and the impact hole plate layer and the outer wall surface of the combustion chamber form a cold air outer duct together; sandwich rice-shaped trusses arranged in a matrix manner are arranged in a 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 rice-shaped truss form a double-wall heat shield together;

the sandwich rice-shaped truss is composed of four truss rods, the middle points of the four truss rods are crossed with each other to form a central cross point, and two ends of the four truss rods are respectively connected with the impact orifice plate and the air film orifice plate; the air film hole plate is provided with air film holes matched with the sandwich rice-shaped truss; the impact orifice plate is provided with impact orifices matched with the sandwich rice-shaped truss, and the air film orifices and the impact orifices are used for forming four longitudinal cooling vortexes extending in the airflow flowing direction between the air film orifice plate layer and the impact orifice plate layer and forming an air film cold air heat insulation layer on the outer wall surface of the air film orifice plate.

Furthermore, among four connecting points of the four truss rods on the air film hole plate, two connecting points on the same circumferential line are positioned at the front part of the central cross point along the airflow direction, the other two connecting points are positioned at the rear part of the central cross point along the airflow direction, the air film hole is arranged among the four connecting points, and the air film hole is a single-row hole or a double-row hole formed by at least three holes along the circumferential direction.

Furthermore, among four connecting points of the four truss rods on the impact orifice plate, two connecting points on the same circumferential line are arranged at the front part of the central cross point along the airflow direction, the other two connecting points are arranged at the rear part of the central cross point along the airflow direction, the impact orifice is arranged among the four connecting points, and the impact orifice is a single-row orifice or a double-row orifice formed by at least three orifices along the circumferential direction.

Further, the matrix arrangement of the plurality of sandwich rice-shaped trusses is specifically as follows: use Sx to arrange the interval for pressing from both sides core rice word truss axial, Sz arranges the interval for pressing from both sides core rice word truss circumference, and H is the distance between gas film orifice plate and the impact orifice plate, and d is the diameter of pressing from both sides core rice word truss, and then two liang of core rice word truss axial and circumferential distance that sets up are:

H≥S_x≥2d、H≥S_z≥2d；

the sandwich rice-shaped truss is continuously extended and arranged according to a set distance in the axial direction of the cavity between the air film pore plate and the impact pore plate, and is alternately extended and arranged according to the set distance in the circumferential direction.

Furthermore, the air film hole is a through hole with a normal included angle of 20-60 degrees with the air film hole plate, and the diameter of the air film hole is 0.3-10 mm.

Further, the change range of the ratio of the diameter d of the sandwich truss shaped like a Chinese character 'mi' to the distance H between the impact orifice plate and the air film orifice plate is as follows: 0.05 to 0.25.

Further, the impact hole is a normal through hole of the impact hole plate; the diameter of the impact hole is 1-2 mm.

Furthermore, the normal angle of the sandwich rice-shaped truss and the wall surface of the air film pore plate is theta, and the theta is 30-60 degrees; the length of a truss rod forming the sandwich rice-shaped truss is l, H is the distance between the air film pore plate (1) and the impact pore plate, and l is H/cos theta.

The invention also provides a method for forming a gas film on a gas film pore plate by using the truss type double-wall heat insulation device for the engine combustion chamber, which comprises the following steps:

part of the cooling air flow in the cold air bypass is vertical to the impact jet flow of the impact orifice plate and enters a cavity between the air film orifice plate and the impact orifice plate through the impact orifices on the impact orifice plate;

the impact jet flow entering the cavity between the air film pore plate and the impact pore plate is partially the impact jet flow which directly performs impact cooling on the inner wall surface of the air film pore plate to form impact cooling air flow, the other part impacts the sandwich rice-shaped truss and collides with the surface of the sandwich rice-shaped truss to form a circumferential flow surrounding the sandwich rice-shaped truss,

one part of the circumambient descending flow of the sandwich rice-shaped truss sweeps and obliquely impacts the inner wall surface of the air film pore plate, the other part of the circumambient descending flow is mixed with the main air flow between the air film pore plate and the impact pore plate, longitudinal cooling vortex systems which are full of cavities at two sides of the sandwich rice-shaped truss are formed at two sides of the rice-shaped truss along the air flow direction, the central cross point of the sandwich rice-shaped truss is taken as a middle point, two parallel longitudinal cooling vortex systems are respectively formed at two sides of the sandwich rice-shaped truss, and the space between the air film pore plate and the impact pore plate is reinforced and cooled;

the circumferential flow which sweeps and obliquely impacts the inner wall surface of the gas film pore plate enters the gas film pores of the gas film pore plate to form airflow jet flow, the airflow jet flow flowing out of the outer wall surface of the gas film pore plate forms a gas film cold air heat insulation layer, and the heat load of the main high-temperature fuel gas in the main fuel gas duct of the combustion chamber on the wall surface of the combustion chamber is reduced.

The invention has the beneficial effects that: the invention provides a truss type double-layer wall heat insulation device for an engine combustion chamber, which structurally comprises a gas-side gas film pore plate, a cold-side impact pore plate and a truss array structure in a shape like a Chinese character 'mi' for connecting the gas film pore plate and the impact pore plate, wherein the impact pore plate and the outer wall surface of the combustion chamber form a cold air duct, the gas film pore plate is the inner wall of a cylinder body of the combustion chamber and is directly contacted with main stream gas, the impact pore plate and the gas film pore plate form a convection heat exchange channel, and the four longitudinal rotating vortexes in the convection channel accelerate heat exchange to take away a large amount of heat between the impact pore plate and the gas film pore plate, so that the temperature between the impact pore plate and the gas film pore plate is rapidly reduced, meanwhile, the cooling pressure on the gas film pore plate is also accelerated and reduced to a large extent, and the service life of an engine is prolonged; an air film cover can be formed on the gas side of the heat shield in an impact-air film composite cooling mode to prevent the gas from directly contacting with a bearing structure of the engine; meanwhile, the sandwich rice-shaped truss structure can effectively fix the impact orifice plate and the gas film orifice plate, so that the structural performance of the sandwich rice-shaped truss structure is enhanced, the service life and the reliability of the combustion chamber are improved, and the sandwich rice-shaped truss structure has better mechanical properties.

Drawings

FIG. 1 is a schematic structural view of a double-walled heat shield of a three-bar truss in the shape of a Chinese character 'mi';

FIG. 2 is a view of a three-bar truss unit in a cross shape and its array structure;

FIG. 3 is a schematic axial cross-sectional view of a double-walled heat shield of a three-bar truss of the present invention in the direction of airflow;

FIG. 4 is a schematic view showing the partial coupling of the double-walled heat shield structure of the three-bar truss in the shape of a cross;

FIG. 5 is a schematic cross-sectional view of a double-walled heat shield of a three-bar truss of the present invention in the direction of airflow.

In the figure, 1, a gas film pore plate, 2, an impact pore plate, 3, a sandwich rice-shaped truss, 4, the outer wall surface of a combustion chamber, 5, a gas film pore, 6, an impact pore, 7, a cold air outer duct and 8, a main stream gas duct.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

Example 1: as shown in figures 1, 2 and 3, the truss type double-wall heat insulation device for the engine combustion chamber comprises a gas film hole plate layer 1 for forming the inner wall of a combustion chamber cylinder body, an impact hole plate layer 2 at the outer side, a combustion chamber main fuel gas duct (8) at the inner side of the gas film hole plate layer 1, a cold air outer duct 7 formed by the impact hole plate layer 2 and the outer wall surface 4 of the combustion chamber, sandwich rice trusses 3 arranged in a matrix mode in a cavity between the gas film hole plate layer 1 and the impact hole plate layer 2, and a double-wall heat insulation screen formed by the gas film hole plate layer 1, the impact hole plate layer 2 and the sandwich rice trusses 3;

the sandwich rice-shaped truss 3 consists of four truss rods, the midpoints of the four truss rods are crossed with each other to form a central cross point, and two ends of the four truss rods are respectively connected with the impact orifice plate 2 and the air film orifice plate 1; the air film hole plate 1 is provided with an air film hole 5 matched with the sandwich rice-shaped truss 3; the impact orifice plate 2 is provided with impact orifices 6 matched with the sandwich rice-shaped truss 3, and the air film orifices 5 and the impact orifices 6 are used for forming four longitudinal cooling vortices extending in the airflow flowing direction between the air film orifice plate layer 1 and the impact orifice plate layer 2 and forming an air film cold air heat insulation layer on the outer wall surface of the air film orifice plate 1.

Among four connecting points of the four truss rods on the air film pore plate 1, two connecting points on the same circumferential line are positioned at the front part of the central cross point along the airflow direction, the other two connecting points are positioned at the rear part of the central cross point along the airflow direction, the air film pores 5 are arranged among the four connecting points, and the air film pores 5 are single-row pores or double-row pores formed by at least three pores along the circumferential direction. The air film hole 5 is a through hole with a normal included angle of 20-60 degrees with the air film hole plate 1, and the diameter of the air film hole 5 is 0.3-10 mm.

Among four connecting points of the four truss rods on the impact orifice plate 2, two connecting points on the same circumferential line are positioned at the front part of the central cross point along the airflow direction, the other two connecting points are positioned at the rear part of the central cross point along the airflow direction, the impact orifice 6 is arranged among the four connecting points, and the impact orifice 6 is a single-row orifice or a double-row orifice formed by at least three orifices along the circumferential direction. The impact hole 6 is a normal through hole of the impact orifice plate 2; the diameter of the impact hole 6 is 1-2 mm.

The matrix arrangement of the plurality of sandwich rice-shaped trusses 3 is as follows: use Sx to arrange the interval for pressing from both sides core rice word truss 3 axial, Sz arranges the interval for pressing from both sides core rice word truss 3 circumference, H is the distance between gas film orifice plate 1 and the impact orifice plate 2, d is the diameter of pressing from both sides core rice word truss 3, then two liang of core rice word trusses 3 axial and circumferential distance that sets up are:

H≥S_x≥2d、H≥S_z≥2d；

the sandwich rice-shaped truss 3 is continuously extended and arranged according to a set distance in the axial direction of the cavity between the air film pore plate 1 and the impact pore plate 2, and is extended and arranged in the circumferential direction according to the set distance in a staggered manner. The ratio variation range of the diameter d of the sandwich rice-shaped truss 3 to the distance H between the impact orifice plate 2 and the air film orifice plate 1 is as follows: 0.05 to 0.25. The normal angle of the sandwich rice-shaped truss 3 and the wall surface of the air film pore plate 1 is theta, and the theta is 30-60 degrees; the length of a truss rod forming the sandwich rice-shaped truss 3 is l, H is the distance between the air film hole plate 1 and the impact hole plate 2, and l is H/cos theta.

The embodiment is a double-wall heat shield for a combustion chamber, and comprises a gas film pore plate 1, an impact pore plate 2 and a sandwich truss shaped like a Chinese character mi 3. The gas film pore plate 1 at the gas side forms the inner wall of a combustion chamber cylinder, and the inner side is a combustion chamber main gas duct 8, namely a flow channel of combustion chamber main stream high-temperature gas A; the cold air side impact pore plate 2 and the outer wall surface 4 jointly form a cold air duct 7; a sandwich rice-shaped truss 3 is arranged between the impact pore plate 2 and the air film pore plate 1 to form a double-wall heat shield together; the sandwich rice-shaped truss 3 is of a typical lattice structure, and is fixed with the air film pore plate 1 and the impact pore plate 2 in a point contact welding mode to form an integral structure with complete structure.

The arrangement mode of the sandwich lattice-shaped truss 3 array structure is shown in figure 2. The sandwich rice-shaped truss 3 is intersected at one point by four truss rods. Generally, four truss rods have the same inclination angle, length and diameter to form a regular polyhedral truss structure. The vertex of the polyhedral truss unit is connected with the impact orifice plate, and the distance Sz of adjacent truss rods in the axial X direction and the row distance Sx of two adjacent rows of sandwich rice-shaped trusses 3 in the circumferential Z direction can be non-constant values.

Along with the change of the angle of the truss rod, the length of the truss rod is changed, the heat conduction capability is changed, and the flow resistance of the fluid is also changed; the increase or decrease in diameter affects the change in the solid fraction and the area of contact with the fluid, and the diameter affects the change in flow resistance and heat exchange performance. The density degree of the array structure can be controlled by the distance between the sandwich rice-shaped trusses 3, when the distance is a constant value, the polyhedral truss array is a regular structure, and when the form of the array structure is changed, the disturbance and mixing of the array structure to the impact jet flow are also changed, so that the cooling efficiency of the inner cooling structure is changed and the amount of cold air is changed.

Example 2: as shown in fig. 4 and 5, the invention also provides a method for forming a gas film on a gas film pore plate by using the truss type double-wall heat insulation device for the engine combustion chamber, which comprises the following steps:

the part of the cooling air flow B in the cold air bypass 7 is vertical to an impact jet flow C1 of the impact orifice plate 2 and enters a cavity between the air film orifice plate 1 and the impact orifice plate 2 through an impact orifice 6 on the impact orifice plate 2;

the impact jet C1 entering the cavity between the air film pore plate 1 and the impact pore plate 2, one part of the impact jet C1 is the impact jet which directly performs impact cooling on the inner wall surface of the air film pore plate 1 to form impact cooling air flow C3, the other part of the impact jet C1 impacts the sandwich rice-shaped truss 3 and collides with the surface of the sandwich rice-shaped truss 3 to form a circumferential flow C2 surrounding the sandwich rice-shaped truss 3,

one part of a circumferential flow C2 which is circularly descended by the sandwich rice truss 3 sweeps and obliquely impacts the inner wall surface of the air film pore plate 1, the other part of the circumferential flow C2 is mixed with a main air flow between the air film pore plate 1 and the impact pore plate 2, longitudinal cooling vortexes C4 which are filled with cavities at two sides of the sandwich rice truss 3 are formed at two sides of the rice truss 3 along the air flow direction, and two parallel longitudinal cooling vortexes C4 are respectively formed at two sides of the sandwich rice truss 3 by taking the central intersection point of the sandwich rice truss 3 as a middle point, so that the space between the air film pore plate 1 and the impact pore plate 2 is reinforced and cooled;

the circumferential flow C2 which sweeps and obliquely impacts the inner wall surface of the gas film pore plate 1 enters the gas film hole 5 of the gas film pore plate to form an airflow jet C5, and the airflow jet C5 which flows out of the outer wall surface of the gas film pore plate 1 forms a gas film cold air heat insulation layer, so that the heat load of the main flow high-temperature gas A in the main gas duct 8 of the combustion chamber on the wall surface of the combustion chamber is reduced.

In fig. 5, it is shown that four longitudinal cooling vortices C4 are formed on two sides of the sandwich lattice truss 3 along the airflow flowing direction, the four longitudinal cooling vortices C4 extend in the airflow flowing direction to rapidly take out heat in the cavity between the air film orifice plate 1 and the impact orifice plate 2, and meanwhile, a cold air heat insulation layer is formed by the jet flow flowing out of the outer wall surface of the air film orifice plate 1 in the air film orifice 5, and the two cooperate to realize the cooling function of the combustion chamber, thereby improving the performance and the service life of the engine.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.