CN110925791A

CN110925791A - Double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure

Info

Publication number: CN110925791A
Application number: CN201911075436.6A
Authority: CN
Inventors: 张群; 胡凡; 程祥旺; 李小龙
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-03-27

Abstract

The invention provides a combustor flame tube wall structure with double wall impact/Y-shaped multi-inclined hole wall composite cooling method. The inner side is a Y-shaped multi-inclined hole cooling wall, and the cooling airflow is ejected from the small holes on the impact wall to impact the cold side of the multi-inclined hole wall to form impact cooling. The cooling air ejected from the impact hole flows to the surrounding walls at the impact point. After encountering the Y-shaped multi-inclined hole, it enters the multi-inclined hole, and then sprays on the gas side of the multi-inclined hole to form a gas film to protect the gas side of the multi-inclined hole wall. , Compared with the traditional multi-inclined hole, the Y-shaped inclined hole has low pressure loss, saves cooling gas consumption, more uniform gas film distribution, low turbulent flow intensity, uniform cooling effect along the axial and circumferential directions of the flame tube, and obtains better The performance of the gas film on the inner wall of the flame tube.

Description

Double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure

Technical Field

The invention relates to a double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure, wherein an impact wall is arranged on the outer side, a Y-shaped multi-inclined hole wall is adopted as the inner multi-inclined-hole wall, the impact wall bears mechanical load, the Y-shaped multi-inclined-hole wall bears thermal load, and the thermal load and the bearing load are separated, so that the service life of a flame tube is prolonged. The design of the Y-shaped multi-inclined-hole increases the area of internal convection heat transfer, enhances the heat transfer and has better cooling effect.

Background

In modern combustors, the temperature of the combustion gases released by the combustion process may exceed 2100 ℃ at most, well above the melting point of the combustor liner and turbine blades. Considerations must therefore be taken with respect to the design of the combustor to adequately cool all metal surfaces exposed to high temperature combustion gases and to improve structural integrity and durability. Furthermore, the amount of cooling air should be minimized to increase the amount of air available for controlling emissions.

The combustor basket is subjected to less mechanical stress than many other components of the engine. However, the liner is subjected to high temperatures and sharp temperature gradients that threaten its structural integrity. To ensure a satisfactory flame tube life, it is important to maintain the temperature and temperature gradient at acceptable levels. Measures must be taken to enhance the heat removal from the liner, typically by radiating into the combustor case and convecting with the annulus air, conventionally by forming a film of cooling air along the inner surface of the liner.

In the aspect of the structural design of the combustion chamber, the combustion performance is good, the structural weight is light, the cooling gas consumption is small, and the thermal fatigue strength is high. The main approach based on the current high-temperature alloy material is to change the cooling mode of the flame tube and the structure of the chamber wall and develop an efficient and advanced cooling technology. At present, the flame tube of the combustion chamber at home and abroad is also developed into a composite cooling form of various cooling modes such as impact, diffusion, air film, laminate and the like from the initial pure air film cooling, and a cooling structure is also developed into a cooling structure form such as a double-layer wall, a floating wall and the like from the initial single-layer wall.

The multi-inclined-hole flame tube cooling technology is a novel efficient cooling technology, has great application value for development potential of high-performance aircraft engines, and has various forms, such as inclined straight holes, shrinkage and expansion holes and the like. The Y-shaped inclined hole is also a multi-inclined hole, and only the cooling air of the Y-shaped inclined hole flows out from a plurality of cooling channel branches, so that compared with other hole types, the air-cooling type Y-shaped inclined hole has the advantages of small pressure loss, small cooling air consumption and more uniform air film distribution. The Y-shaped multi-inclined hole has been researched in the field of difficult film cooling of a turbine of an aircraft engine, but the research on the technical field of flame tube wall cooling is very little, and the research on the double-layer composite wall is not carried out, and the structure is invented on the basis of the background.

Disclosure of Invention

The invention aims to solve the technical problem of providing a double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure, wherein the outer side of the double-wall is an impact wall, and the inner side of the double-wall is a Y-shaped multi-inclined-hole wall, so that the problem of poor cooling effect of the combustion chamber flame tube is solved.

Technical scheme

The invention aims to provide a double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure.

The technical scheme of the invention is as follows:

the double-wall composite cooling structure consists of two layers of walls, including outer impact wall with several small holes perpendicular to the wall and inner Y-shaped multiple inclined hole cooling wall. The Y-shaped cooling wall structure comprises a main air inlet hole and four air film separating holes, wherein the air film separating holes are positioned on each branch of the cooling inclined channel, and the included angles between the air film separating holes and the branches of the cooling inclined channel are 90 degrees. And cooling air flow is sprayed from the small holes on the impact wall and impacts the cold side of the multi-inclined-hole wall to form impact cooling. The cooling air ejected from the impact holes flows towards the periphery of the impact point and enters the main air inlet holes of the multiple inclined holes after encountering the Y-shaped multiple inclined holes, then the cooling air is ejected from the distribution film holes of the multiple inclined holes to form an air film on the gas side of the multiple inclined hole wall, and the air film is formed on the wall surface of the flame tube for cooling, so that the gas side of the multiple inclined hole wall is protected.

The invention has the following beneficial effects:

the double-wall composite cooling structure designed by the invention has the outer side of the impact wall and the inner side of the Y-shaped multi-inclined hole wall, the impact wall bears mechanical load, the Y-shaped multi-inclined hole wall bears thermal load, and the thermal load and the bearing force are separated, so as to improve the service life of the flame tube, meanwhile, the multi-inclined hole wall adopts a Y-shaped multi-inclined hole which is different from the traditional multi-inclined hole structure, the Y-shaped multi-inclined-hole mainly comprises a main air inlet hole and four air distribution film holes, wherein the air distribution film holes are located in each branch of a cooling inclined channel, a plurality of small holes which are uniformly vertical to the wall surface are distributed in an impact wall, the inner side wall is uniformly distributed with the Y-shaped multi-inclined-hole which penetrates through the inner side wall surface, the Y-shaped multi-inclined-hole wall hot side air film adherence is good by properly adjusting pressure drop distribution between double layers of walls, and the inlet and outlet angles and the inlet and outlet diameters of the Y-shaped inclined-hole are reasonably adjusted, so that a good air film cooling effect can be obtained. The Y-shaped multi-inclined-hole gas is low in pressure loss, cooling gas consumption is saved, gas films are distributed more uniformly, turbulence intensity is low, the cooling effect is uniform along the axial direction and the circumferential direction of the flame tube, and the problem that the wall surface cooling effect is not uniform due to uneven gas film thickness near the wall surface of the flame tube is solved. The double-wall structure enables the temperature distribution of the wall surface of the flame tube to be more uniform, reduces the temperature gradient of the wall surface of the flame tube, avoids overhigh thermal stress and prolongs the service life of the flame tube.

Description of the drawings

FIG. 1: schematic diagram of the double-wall overall structure of the invention

FIG. 2: cross section view of flame tube wall plate in axial direction of structure of the invention

FIG. 3: double-walled outer impact wall schematic of the invention

FIG. 4: the schematic diagram of the double-wall inner layer Y-shaped wall distribution membrane pores

FIG. 1 shows 1-impact wall, 2-multi-inclined hole wall, 3-impact small hole on impact wall, 4-Y-shaped multi-inclined hole

Detailed Description

The invention will now be further described with reference to the accompanying drawings in which:

as shown in the figure, the invention provides a double-wall impact/Y-shaped multi-inclined-hole-wall composite cooling type combustion chamber flame tube wall surface structure, which comprises an outer impact wall and an inner Y-shaped multi-inclined hole wall, wherein the Y-shaped cooling wall structure comprises a main air inlet hole and four air film separating holes, the air film separating holes are positioned on each branch of a cooling inclined channel, and the included angles of the air film separating holes are 90 degrees. The cooling air flow is ejected from the small holes on the impact wall and impacts the cold side of the multi-inclined-hole wall to form impact cooling. The cooling air ejected from the impact holes flows towards the periphery of the impact point and enters the main air inlet holes of the multiple inclined holes after encountering the Y-shaped multiple inclined holes, then the cooling air is ejected from the distributed film holes of the multiple inclined holes to form an air film on the gas side of the multiple inclined hole wall, and the air film is formed on the wall surface of the flame tube for cooling, so that the gas side of the multiple inclined hole wall is protected.

The combustion chamber flame tube wall surface structure adopting the double-layer wall impact/Y-shaped multi-inclined-hole wall composite cooling mode has the advantages that the impact bears mechanical load, the multi-inclined-hole wall bears thermal load, and the thermal load and the force bearing are separated, so that the service life of the flame tube is prolonged, the double-layer wall surface composite mode is adopted, and the characteristic of high impact cooling heat exchange coefficient is fully utilized; many inclined hole walls of Y type comprise a main inlet port and four distribution membrane holes, and the distribution membrane hole is located each branch of cooling inclined channel, and cooling gas is when passing Y type inclined hole, along flame tube axial direction, the wall can be laminated more to the gas film, and gas film thickness is also more even, and the flow state of gas film is also more stable. In addition, the air films formed between the different Y-shaped inclined holes have the effect of mutual compensation, and the flowing state of the air flow at the outlet of each air film separating hole is more stable. Because the diameter of the main air inlet hole is larger than that of the air film separating hole, the air flow pressure loss is low, the air consumption for cooling is saved, the turbulence intensity is reduced, and a good air film cooling effect is obtained. Meanwhile, the double-wall structure adjusts the pressure drop distribution between the double walls properly, so that the hot-side gas film of the multi-inclined-hole wall adheres well, and the full gas film protection is formed.

Claims

1. the wall surface structure of the combustion chamber flame tube of a double-layer wall impact/Y-type multi-inclined hole wall composite cooling mode, it is characterized in that: this composite cooling mode is made up of double-layer walls, and the outside is an impact wall, and the inside is a Y-shaped multi-layer wall. Oblique hole wall.

2. a kind of double-wall structure according to claim 1, the impact wall surface of its outer side wall surface is distributed with numerous small holes that are evenly perpendicular to the wall surface, and the inner Y-shaped multi-inclined hole wall is distributed with numerous uniform inclined holes, The inclined hole is mainly composed of a main air inlet hole and four distributed air film holes, and the distributed film holes are located on each branch of the cooling inclined channel.

3. A kind of double-layer wall surface cooling structure according to claim 1, 2 is characterized in that: the small holes on the impact wall surface are evenly distributed, the aperture is about 1mm, and the main air inlet holes of the Y-shaped multi-inclined hole wall are divided into two parts. The diameter of the circular hole formed by the gas film hole on the wall surface of the flame cylinder ranges from 0.5 to 2 mm, and the diameter of the main air inlet hole is larger than that of the distribution film hole, and the angle between the main air inlet hole and the axis of each gas distribution film hole is located. Both are around 90°.

4. The Y-shaped oblique hole wall surface of a double wall surface cooling structure according to claim 1, 2 or 3, is characterized in that: the adjacent row oblique holes in the axial direction of the flame tube are arranged in a fork row and a straight row. In this way, the range of the row spacing is 1 to 10 times the diameter of the hole. The Y-shaped inclined holes in the same row on the flame cylinder have the same shape and hole spacing, and the holes in different rows can have different hole spacing. The range is 1 to 10 times the pore size, and the angle between adjacent distributed membrane holes can be 0 to 45°. More combinations can be obtained through different arrangements to obtain better cooling effects.

5. a kind of double-wall impact/Y-type multi-inclined hole wall composite cooling mode combustion chamber flame tube wall surface structure according to claim 1, the cooling airflow is ejected from the small holes on the impact wall, and the impact is The cold side of the inclined hole wall forms impact cooling. The cooling air ejected from the impact hole flows to the surrounding walls at the impact point. After encountering the Y-shaped multi-inclined hole, it enters the main air intake hole of the multi-inclined hole, and then sprays from the distributed film hole of the multi-inclined hole to the multi-inclined hole. The gas film is formed on the gas side of the wall, and the gas film is formed on the wall surface of the flame cylinder to cool, and protect the gas side of the multi-slope hole wall.

6. a kind of double wall impact/Y type multi-inclined hole wall composite cooling mode combustion chamber flame tube wall surface structure according to claim 1, its impact wall bears mechanical load, Y-type multi-inclined hole wall bears thermal load, Heat and force are separated to improve the service life of the flame tube. The design of the Y-shaped multi-inclined holes increases the internal convection heat exchange area, strengthens the heat exchange, and has a better cooling effect.