阅读说明：本技术 一种带有尾部冷却结构的燃烧室 (Combustion chamber with tail cooling structure ) 是由 张群 李小龙 胡凡 程祥旺 于 2020-03-25 设计创作，主要内容包括：本发明提供一种带有尾部冷却结构的燃烧室。基于传统燃烧室产生的大量热会对涡轮叶片产生较大的影响,本结构主要特征是在火焰筒尾部设置导向器冷却装置并对燃烧室机匣与火焰筒壁面采用楔形连接方式,一方面对火焰筒前方过来的燃气流产生一个偏转角度,为后面涡轮结构对燃气流的偏转做准备；另一方面将导向器设置为空心结构,且导向器上设置冷却孔,将机匣与火焰筒壁面间的空气流引入火焰筒对燃气流进行冷却作用,这种冷却结构可以对火焰筒中所产生的高温燃气流及时冷却,达到较好的冷却效果,减小高温燃气流对燃烧室及涡轮组的持续损耗,间接缩短发动机长度,减轻发动机总重量,延长发动机寿命。(The invention provides a combustion chamber with a tail cooling structure. Based on the fact that a large amount of heat generated by a traditional combustion chamber can generate great influence on turbine blades, the structure is mainly characterized in that a guider cooling device is arranged at the tail part of a flame tube, a combustion chamber casing is connected with the wall surface of the flame tube in a wedge-shaped mode, and on one hand, a deflection angle is generated for gas flow coming from the front of the flame tube, so that preparation is made for the deflection of the gas flow by a rear turbine structure; on the other hand sets up the director to hollow structure, and sets up the cooling hole on the director, introduces the air current between machine casket and flame tube wall and carries out the cooling action to the flame tube, and this kind of cooling structure can in time cool off the high temperature gas stream that produces in the flame tube, reaches better cooling effect, reduces the continuous loss of high temperature gas stream to combustion chamber and turbine group, indirectly shortens engine length, alleviates engine total weight, extension engine life.)

1. The utility model provides a combustor with afterbody cooling structure, its structure includes basic structure such as combustor casing, diffuser, flame tube, swirler, nozzle and mixes the guider behind the district, its characterized in that: based on the fact that the traditional combustion chamber generates oxygen-poor combustion in a mixing zone and generates a large amount of heat in a pre-combustion zone and a middle zone, the structure and the stress intensity of the turbine blade are greatly influenced, a group of guider devices are arranged behind a flame tube mixing zone, and on one hand, a deflection angle is generated on gas flow coming from the front of a flame tube; on the other hand, the guider is arranged to be a hollow structure, the guider is provided with a vent hole and is connected with air flow flowing between the casing of the combustion chamber and the wall surface of the flame tube, and the casing and the tail part of the flame tube are in a wedge-shaped closed structure.

2. The combustor with aft cooling structure of claim 1, wherein: the guider is of a hollow structure, is designed at a position about 1cm behind a mixing region in the flame tube, has a certain angle deflection, is equivalent to the deflection angle of the turbine structure, is circumferentially distributed around the flame tube, and the number of the guider is determined according to the compressor-turbine set.

3. The combustor with aft cooling structure of claim 1, wherein: the wall surface of the guider is provided with regular small holes with the aperture of 1mm, the small holes are arranged in a row, the hollow device of the guider is communicated with air flow between the wall surface of the flame tube and the combustion chamber casing, and the guider is connected with the wall surface of the flame tube in a welding mode and is used for leading in air flow outside the flame tube from the guider, then leading out the air flow through the small holes on the wall surface of the guider and fully mixing the air flow with high-temperature gas flow flowing out of the mixing area.

4. The combustor with aft cooling structure of claim 1, wherein: the combustion chamber structure leads most of air flow between the wall surface of the flame tube and the combustion chamber casing to the guider, the combustion chamber casing gradually shrinks towards the wall surface of the flame tube to form a wedge-shaped structure, and a smaller radian is arranged at a shrinkage angle, so that the resistance of the air flow entering the guider is reduced.

Technical Field

The invention belongs to the field of aero-engine combustion chambers, and particularly relates to a combustion chamber with a tail cooling structure.

Background

The performance of an aviation gas turbine as an advanced representative in a thermal power device directly represents the national industrial technology level, so that the improvement of the overall performance of the aviation gas turbine is an important direction for continuous development. Modern gas turbines mainly comprise three parts, namely a compressor, a combustion chamber and a turbine, so that the research on the combustion chamber is mainly the improvement on the three parts. The compressor, which is the front-end unit of the gas turbine, has little effect on heat generation and is not necessarily studied for cooling. Combustors and turbine wheels have been the focus of cooling research as high temperature components of engines. In contrast, cooling of a turbine is studied more, and cooling of a combustor is a big problem, and it is difficult to satisfy that an airflow flowing out of the combustor meets a turbine front gas temperature limit.

In the current research, cooling modes of a combustion chamber are mainly divided into passive thermal protection and active thermal protection, and a passive thermal protection technology (such as thermal insulation layer ablation cooling) is mainly used in an aircraft with a high combustion chamber temperature, such as a combustion chamber of an aerospace engine, and an active thermal protection technology is mainly adopted for the aero-engine, namely, cold air flow flowing out from a gas compressor flows through the wall surface of a flame tube, and cooling of gas inside the flame tube is avoided.

At present, the cooling mode of the combustion chamber mainly has four types: convection cooling, film cooling, impingement cooling and divergent cooling, and other novel cooling technologies are all in accordance with the situation of the four modes. Convection cooling, i.e. low-temperature cold air takes away heat on the wall surface of the flame tube in a convection heat exchange mode, the cold air is not mixed with hot gas, although the mode is simple to process, the cooling effect is limited, so that the applicability is poor, and the low-temperature cold air can only be used as auxiliary cooling. Film cooling is most widely used in current gas turbines, and is performed by introducing cool air into a flame tube in some form of intake air and flowing down along the wall surface of the flame tube to form a film between the inner wall surface and hot gas. The porous diffusion cooling is distributed with diffusion holes on the cooling wall surface of the flame tube, and cold air enters from the outer wall of the flame tube through the small holes and forms a continuous and uniform air film blanket on the inner wall, so that the cooling area can be increased. The impingement cooling adopts a double-layer flame tube wall surface, cold air enters from the outer wall in a direction perpendicular to the wall surface and impinges on the wall surface with the higher temperature of the inner wall, but the impingement cooling is only suitable for cooling local hot spots of the flame tube, and the airflow pressure drop loss is large. The cooling of the gas turbine is a very important subject, the cooling technology of the flame tube is mainly mastered in the countries of leading-edge aviation technologies of the American, German, Italy, English and French, the research on the cooling technology of the combustion chamber is continuously developed because the technology of the gas turbine is started late and the technology is lagged behind in China, and the single cooling method has certain limitation and the cooling effect is limited.

The invention can effectively meet the cooling requirement by improving the flame tube and the shell mechanism of the combustion chamber of the aircraft engine, after the cold air flow on the outer wall of the flame tube passes through the mixing hole, because the shell of the combustion chamber and the outer wall of the flame tube are gradually closed, the air flow gradually flows into the guider and then flows into the flame tube through the small hole on the wall surface of the guider, and the air flow is fully mixed with the hot air flow from the mixing area to form mixed air flow with a certain angle, thereby realizing the air flow cooling on the tail part of the flame tube.

Disclosure of Invention

The invention aims to solve the technical problem of providing a combustion chamber with a tail cooling structure. Compared with the existing combustion chamber structure, the invention has the advantage that the rear part of the flame tube mixing area and the combustion chamber shell are reasonably changed on the basis of the original flame tube structure. The rear part of the flame tube mixing area is added with a row of guide devices, the number of the guide blades is equivalent to that of the turbine blades, the guide devices are circumferentially distributed on the wall surface of the flame tube at a certain angle, small holes in regular shapes are formed in the wall surface of each guide device, cold air flow flowing out of each guide device is fully mixed with hot air flow flowing from the front part of the flame tube, the air flow mixing area is increased, loss of a combustion chamber caused by a gas flow flowing path is reduced, formed mixed air flow flows into a turbine group along with the guide devices at an angle, and preparation is made for the subsequent expansion acceleration process of the mixed air flow. On the outer wall of the flame tube, the combustion chamber shell gradually contracts inwards, approaches to the outer wall surface of the flame tube and is connected with the outer wall surface of the flame tube in an arc at the approaching position, cold air on the outer wall surface is gradually introduced into the guider, the cold air amount is increased, and the cooling effect is enhanced.

Technical scheme

The invention aims to provide a combustion chamber with an end cooling structure.

The technical scheme of the invention is as follows:

a combustion chamber with tail cooling structure is composed of casing, diffuser, flame tube, cyclone, nozzle and rear guider of mixing region. The method is characterized in that: based on the fact that the traditional combustion chamber generates oxygen-poor combustion in a mixing zone and generates a large amount of heat in a pre-combustion zone and a middle zone, which can generate great influence on the structure and the stress intensity of the turbine blade, the structure adopts the mode that a group of guider devices are arranged behind a flame tube mixing zone, on one hand, a deflection angle is generated on gas flow coming from the front of a flame tube, and preparation is made for the deflection of the gas flow of a rear turbine structure; on the other hand, the guider is arranged to be of a hollow structure, the air hole is formed in the guider and connected with air flow flowing between the casing of the combustion chamber and the wall surface of the flame tube, the tail portion of the casing and the tail portion of the flame tube are of a wedge-shaped closed structure, the air flow between the casing and the wall surface of the flame tube is mainly introduced into the flame tube to cool the air flow, and the cooling structure has a good cooling effect.

The guider in the flame tube is characterized in that: the guider is designed in the flame tube, namely after the mixing area, the high-temperature gas flow generated in the flame tube is timely cooled, and the high-temperature gas flow does not continuously flow to the turbine unit, so that the continuous loss of the high-temperature gas flow to a combustion chamber is reduced, the length of an engine is indirectly shortened, and the total weight of the engine is reduced. The designed guider has a certain angle deflection, the design angle is equivalent to the deflection angle of the turbine structure, the guider is circumferentially distributed around the flame tube, and the number of the guider is determined according to the compressor-turbine group. The guide is of hollow construction and is of a material sufficient to withstand the high temperature extremes of the gas stream generated in the liner without creep, whilst reducing the overall weight of the guide assembly. The wall surface of the guider is provided with regular-shaped small holes which are arranged in an inserting and arranging manner, the hollow device of the guider is communicated with the wall surface of the flame tube and the combustion chamber casing through air flow, and the guider is connected with the wall surface of the flame tube in a welding manner and is used for leading in the air flow outside the flame tube from the guider and then flowing out through the small holes on the wall surface of the guider to be fully mixed with the high-temperature gas flow flowing out of the mixing area.

Flame tube wall and combustion chamber shell structure, its characterized in that: most of air flow at the rear section between the wall surface of the flame tube and the combustion chamber casing is led into the guider by the structure, the combustion chamber casing gradually shrinks towards the wall surface of the flame tube to form a wedge-shaped structure, and a smaller radian is arranged at a shrinkage angle, so that the resistance of the air flow entering the guider is reduced.

The invention has the following beneficial effects:

the combustor with the tail cooling structure has the advantages that the front end position of the whole flame tube combustor is basically unchanged from the main structure of the traditional combustor, including the combustor inlet, the diffuser, the swirler and the nozzle part, only the rear section part is improved, a good cooling effect is achieved, the temperature of gas before a turbine reaches a proper state, the consumption of the turbine structure is reduced to the minimum, and the service life of an engine is prolonged.

Drawings

FIG. 1: annular combustor partial profile

FIG. 2: details of the cooling device of the guide

FIG. 3: detail view of flame tube

FIG. 4: overall structure diagram of annular combustion chamber

In the figure: 1-combustion chamber casing, 2-swirler, 3-flame tube wall surface, 4-guider cooling device, 5-combustion chamber casing and flame tube connecting portion, 6-cooling hole and 7-air leading-in zone.

Detailed Description

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

with reference to fig. 1, 2, 3 and 4, the present invention is a combustor with an aft cooling structure. FIG. 1 is a partial outline view of an annular combustion chamber, FIG. 2 is a detailed view of a pilot cooling device, FIG. 3 is a partial detailed view of a combustor basket, and FIG. 4 is an overall structural view of the annular combustion chamber.

In order to make the temperature of the combustion chamber after complete combustion meet the maximum temperature limit in front of the turbine, a group of guider cooling devices are added at the tail end of the flame tube. Cold air flow from the compressor flows through a diffuser, enters the combustion chamber, one part of the air flow passes through the swirler and is mixed and combusted with fuel oil in the flame tube under the action of the swirler 2 and the flame tube, the other part of the air flow flows along the casing wall 1 of the combustion chamber and the outer wall surface 3 of the flame tube, flows into one part of the air through the main combustion hole, the middle hole and the mixing hole and enters the combustion chamber to play the roles of mixing and local cooling, the cooling effect is not obvious when the air flow reaches the rear part of the mixing region of the flame tube, a group of guider cooling devices 4 are added at the rear part of the guider cooling devices and are connected with the wall surface of the flame tube through welding, the residual air flow flowing through the mixing hole is close to the outer wall surface of the flame tube and is connected with the connecting part 5 of the flame tube by the casing of the combustion chamber, an inner-shrinkage wedge-shaped structure is close to the outer wall surface of the, a large amount of cold air flows enter the flame tube through the cooling holes 6 and are mixed with high-temperature hot gas of incoming flow, on one hand, secondary combustion can be carried out on incompletely combusted gas, combustion efficiency is increased, no pollutants are generated in the air flow at the outlet of the combustion chamber, on the other hand, the mixing area of the air flow is increased, and the loss of the combustion chamber caused by the flowing path of the gas flow is shortened. The guide structure of the cooling device promotes the formed mixed gas flow to flow into the turbine group along with the guider in an angle, so that preparation is made for the subsequent expansion acceleration process of the mixed gas flow, and the design of the combustion chamber is optimized.