CN112963862A

CN112963862A - Double-layer rhombic cross cooling structure

Info

Publication number: CN112963862A
Application number: CN202110372851.9A
Authority: CN
Inventors: 张群; 马晓曦; 王晓燕; 王紫欣; 高耀红
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2021-04-07
Filing date: 2021-04-07
Publication date: 2021-06-15

Abstract

The invention provides a double-layer rhombic cross cooling structure which consists of an impact hole wall and a divergent hole wall, wherein cooling pipelines with certain diameters are distributed in the two walls in a cross mode, and the impact holes are distributed on the cross points of cooling channels in a rhombic mode. The composite cooling structure has small pressure loss and high cooling efficiency, the internal cooling channel obviously improves the heat exchange area and leads away a part of air flow, the outflow speed of the small hole is reduced, the diffusion capacity is enhanced, and the cooling effect is enhanced. Thereby the cooling capacity of the cooling air flow is better exerted, and the service life of the combustion chamber is prolonged.

Description

Double-layer rhombic cross cooling structure

Technical Field

The invention relates to the technical field of gas turbine engines, in particular to a double-layer rhombic cross cooling structure.

Background

As turbine engine performance increases, the engine pressure ratio and combustor temperature rise gradually increase, which places greater thermal loads on the liner walls. The combustion air amount increases while the intake air amount does not change, so the cooling air amount can only be decreased. Therefore, more advanced cooling technology is required to achieve better cooling effect on the premise of not increasing the amount of cold air.

The traditional flame tube wall generally adopts cooling modes such as divergent cooling, air film cooling, impact air film cooling and the like, the structure is also a single-layer wall structure, the basic principle is that cold air enters an inner ring cavity and an outer ring cavity of a combustion chamber through various pores, an air film is formed on the inner wall of the inner ring cavity, and the cooling effect is achieved. The traditional cooling structure has low overall cooling efficiency and cannot well adapt to the current situations of increasing the heat load and reducing the cold air quantity of the current turbine engine. In recent years, micro-hole cooling technology has become an important development direction for advanced turbine engine hot-end component cooling technology.

Disclosure of Invention

The invention aims to solve the technical problem of providing a double-layer rhombic cross cooling structure. Compared with the prior art structure, the invention has the advantage of applying a composite cooling structure. The defect of overlarge difference of heat exchange coefficients at the far and near positions of an impact air film cooling stagnation point is overcome. Cold air is introduced into the rhombic impact holes designed on the outer wall, so that cold flow is provided for the cooling channel in the wall while air film cooling is performed. Although the shape of the divergent hole is the same as that of the impact hole and is also right opposite to the intersection point of the cooling pipeline, the whole divergent hole gradually expands in the expansion trend, so that the average outflow speed of the small hole is reduced, the diffusion capacity is enhanced, the cooling effect is better than that of a circular gas film hole, and the high temperature rise of the combustion chamber is realized.

Technical scheme

The invention aims to provide a double-layer rhombic cross cooling structure which can effectively improve the cooling effect on the premise of not increasing the gas consumption and realize high temperature rise of a combustion chamber.

The technical scheme of the invention is as follows:

a double-layer rhombic cross cooling structure comprises an impact hole wall and a divergence hole wall.

The impact hole wall is characterized in that: rhombic impact holes are distributed on the wall surface, the area difference of the inlet and the outlet of the holes is not large, the rhombic holes are over against the intersection of the cooling pipelines, and the diagonals of the rhombuses are respectively 3mm and 4 mm.

The divergent pore wall is characterized in that: similar diamond holes are distributed at the crossing part opposite to the cooling pipeline, the area of the holes is gradually enlarged from the inlet, the area of the inlet holes is the same as that of the impact holes, and the diagonals of the outlet diamond holes are respectively 4mm and 5 mm.

The cooling pipeline is characterized in that: the cooling device is characterized in that circular holes with the diameters of 3-5 mm are distributed in a crossed mode, a rhombic cooling chamber is formed at the crossed position of pipelines, impact holes are connected to the cooling chamber, and the cooling chamber is communicated with radiating holes downwards and is communicated with cooling channels on the periphery.

The invention has the following beneficial effects:

the invention relates to a double-layer rhombic cross cooling structure, which has the advantages that the composite structure simultaneously utilizes the cooling technologies of small hole impingement cooling, small hole air film cooling, inner wall cooling channels, special-shaped hole structures and the like based on micro-hole cooling, so that the double-layer rhombic cross cooling structure obtains better cooling effect, smaller pressure loss, larger air film covering area and larger heat exchange area, and the heat exchange effect is obviously improved.

Drawings

FIG. 1: integral schematic diagram of double-layer rhombic cross cooling structure

FIG. 2: divergent pore wall front view of double-layer rhombic cross cooling structure

FIG. 3: cross-sectional view of double-layer rhombic cross cooling structure

In the figure: 1. impact hole wall, 2, divergence hole wall, 3, impact hole, 4, divergence hole, 5, internal cooling pipeline, 6 and cooling chamber.

Detailed Description

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

with reference to fig. 1, 2 and 3, the present invention is a double-layer diamond-shaped cross cooling structure.

When the double-layer rhombic cross cooling structure works, cold air flow enters the cooling chamber (6) of the inner wall from the impact holes (3) on the surface of the impact hole wall (1) and impacts the same, cold air is shunted from the cooling chamber (6), a part of the cold air enters the cooling pipeline (5) to perform first-time convective heat transfer on the inner surface of the pipeline for cooling, the cross distribution of the cooling pipeline (5) can increase the heat transfer area and enable the air flow to be disturbed mutually, and the heat transfer is further enhanced; the other part of the airflow flowing into the diverging hole (4) is decelerated and expanded in the gradually expanded hole, and finally forms an air film on the surface of the diverging hole wall (2), so that the wall surface is prevented from being directly contacted with high-temperature airflow, partial heat of a near-wall area is taken away, and the aim of cooling the wall surface is fulfilled.

Claims

1. The utility model provides a double-deck rhombus alternately cooling structure which characterized in that: the double-layer rhombic cross cooling structure comprises double-layer wall surfaces, namely an impact hole wall and a divergent hole wall; the rhombic impact holes are positioned on the impact hole wall, and the diagonal lengths are 3mm and 4mm respectively; the rhombic diverging holes are positioned on the diverging hole walls, and the diagonal lengths are 4mm and 5mm respectively; the diameter of the cross cooling channel is 2.5mm, and the included angle of the two channels is 72 degrees; and air vents with the aperture of 3mm are distributed on the side wall surface.

2. The double-layer diamond-shaped cross cooling structure of claim 1, wherein: the centers of the rhombic impact holes and the rhombic diverging holes are opposite to the intersection points of the cooling channels.

3. The double-layer diamond-shaped cross cooling structure of claim 1, wherein: the impact hole and the divergence hole are both rhombus, but the section of the impact hole is not changed, while the section of the divergence hole is changed from small to large, and the cross sections of the inner wall and the impact hole are both 6mm²Expanding to 10mm at the outer wall²。