Gas turbine engine and diffuser thereof

Abstract

The invention aims to provide a diffuser which is used in a combustion chamber of a gas turbine engine, and a cavity is formed between the diffuser and a high-pressure rotor of the gas turbine engine. Wherein the diffuser is provided with an outer side wall, the cavity is defined by the outer side wall and the high-pressure rotor, a plurality of cooling holes are formed in the outer side wall, each cooling hole enables the cavity to be communicated with an inner cavity of the diffuser, and a circulating cooling system is formed. The diffuser with the structure has the characteristic of long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine engines, and in particular to a gas turbine engine and a diffuser thereof. Background Art

[0002] Modern high bypass ratio turbofan aircraft engines are a type of gas turbine, usually consisting of an air inlet, a fan booster stage, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and a tail nozzle in series. The combustion chamber is one of the core components of a gas turbine, used to mix high-temperature and high-pressure gas and fuel, and burn them to achieve the purpose of heating and pressurization.

[0003] The airflow speed from the compressor to the combustion chamber is very high, which can reach between 120m / s and 220m / s. It is difficult for fuel to burn stably in such a high-speed airflow. In order to reduce the speed and increase the pressure of the gas transmitted from the compressor to the combustion chamber to make it more conducive to combustion, a diffuser is generally installed in the combustion chamber. The diffuser is generally connected to the outer casing of the combustion chamber by bolting or welding, which can convert most of the kinetic energy of the high-speed airflow into static pressure and form a relatively stable flow field.

[0004] In working conditions, the high gas temperature at the diffuser will reduce the service life of the diffuser. How to provide a diffuser with a long service life is an urgent problem that needs to be solved. Summary of the invention

[0005] An object of the present invention is to provide a diffuser which has the characteristic of long service life.

[0006] A diffuser for achieving the aforementioned purpose is used in a combustion chamber of a gas turbine engine, wherein a cavity is formed between the diffuser and a high-pressure rotor of the gas turbine engine;

[0007] The diffuser has an outer wall, the cavity is surrounded by the outer wall and the high-pressure rotor, a plurality of cooling holes are opened in the outer wall, and each cooling hole connects the cavity with the inner cavity of the diffuser.

[0008] In one or more embodiments, a circulating cooling system is formed on the diffuser through the cooling holes.

[0009] In one or more embodiments, a plurality of cooling holes are arranged in the outer wall along the circumference of the outer wall.

[0010] In one or more embodiments, the plurality of cooling holes are evenly distributed along the circumference of the outer side wall.

[0011] In one or more embodiments, the outer side wall has a thickened portion, the thickness of the side wall increases at the thickened portion, and the cooling hole is opened in the thickened portion.

[0012] In one or more embodiments, the thickened portion includes a first protrusion protruding from the outer side wall toward the cavity and / or a second protrusion protruding from the outer side wall toward the inner cavity of the diffuser.

[0013] In one or more embodiments, the cooling hole has an outlet located on the cavity side and an inlet located on the inner cavity side of the diffuser, and an extension direction of the cooling hole from the inlet to the outlet is inclined toward the axis of the diffuser so that an acute angle is formed between the extension direction and the axis of the diffuser.

[0014] In one or more embodiments, a central axis of the cooling hole is inclined toward a rotation direction of the high-pressure rotor.

[0015] In one or more embodiments, the cooling hole is opened in the middle portion of the outer side wall.

[0016] On the other hand, according to some embodiments of the present application, a gas turbine engine is provided, which includes a high-pressure rotor and a combustion chamber, wherein the combustion chamber includes an outer combustion casing and a diffuser, and is characterized in that the diffuser is the diffuser as described above.

[0017] The beneficial effects of the present invention are:

[0018] By opening a cooling hole in the outer wall of the diffuser near the cavity, a portion of the relatively low-temperature cooling gas located in the inner cavity of the diffuser can be introduced into the cavity through the cooling hole, thereby lowering the temperature of the gas in the cavity, thereby reducing the problem of continuous increase in the temperature in the cavity caused by irregular flow of the gas in the cavity. At the same time, the flow of the cooling gas will also generate heat exchange with the wall of the diffuser, thereby reducing the wall temperature and temperature gradient of the diffuser near the cavity, which can effectively increase the service life of the diffuser.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0021] Figure 1shows a schematic diagram of some embodiments of the gas turbine engine according to the present invention;

[0022] Figure 2 A partial schematic diagram of some embodiments of the diffuser is shown;

[0023] Figure 3 A partial perspective schematic diagram of some embodiments of the diffuser is shown;

[0024] Figure 4 A schematic diagram of internal air circulation according to some embodiments of the present diffuser is shown. DETAILED DESCRIPTION

[0025] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0027] The technical definitions described in one or more of the following embodiments are as follows:

[0028] Gas turbine engine: An internal combustion power unit that uses a continuously flowing gas as a working fluid to convert the heat energy generated by the combustion of fuel into useful work; a special type of gas turbine is the high-bypass turbofan aero engine.

[0029] Combustor: One of the core components of a gas turbine, it mainly consists of a combustion chamber casing, diffuser, fuel nozzle and flame tube.

[0030] Case: The outer wall of the combustion chamber. Its main functions are to install and connect the main components and sensing parts of the combustion chamber; to contain the high-temperature and high-pressure gas in the combustion chamber; and to bear and transmit loads such as axial force. It is internally connected to the diffuser.

[0031] Diffuser: It is used to reduce the speed and increase the pressure of the gas transmitted from the compressor to the combustion chamber to make it more conducive to combustion.

[0032] Figure 1The schematic diagram of some embodiments of the gas turbine engine is shown, the gas turbine engine includes a high-pressure rotor 91 and a combustion chamber 92. Specifically, in the structure shown in the figure, the gas turbine engine also includes an air inlet 93, a fan 94, a planetary gearbox 95, a low-pressure compressor 96, a high-pressure compressor 97, a high-pressure turbine 98, a low-pressure turbine 99 and a low-speed shaft 90. The atmosphere 101 enters the gas turbine engine and is divided into two streams, an external airflow 102 and an internal airflow 103. Among them, the combustion chamber 92 includes a diffuser 1.

[0033] In order to improve the life of the diffuser, a diffuser is further provided according to some embodiments of the present application. The diffuser is used as follows: Figure 1 In the combustion chamber of a gas turbine engine shown in Figure 2 shows a partial schematic diagram of some embodiments of the diffuser, Figure 3 A partial stereoscopic schematic diagram according to some embodiments of the diffuser is shown, wherein the combustion chamber 92 includes a diffuser 1 and a combustion chamber casing 920, and the combustion chamber casing 920 is fixedly connected to a high-pressure compressor casing 970. A cavity 10 is formed between the diffuser 1 and the high-pressure rotor 91 of the gas turbine engine. Specifically, the diffuser 1 has an outer wall 11, and the cavity is surrounded by the outer wall 11 of the diffuser 1 and the high-pressure rotor 91. A plurality of cooling holes 110 are provided in the outer wall 11, and each cooling hole 110 connects the cavity 10 with the inner cavity 12 of the diffuser 1. It can be understood that the diffuser 1 is a rotating part structure, Figure 2 The schematic diagram only shows a cross section of the diffuser 1, and only one cooling hole 110 is shown in the figure. In other parts of the diffuser 1 not shown in the figure, multiple cooling holes 110 may be provided. In some specific embodiments, the cooling hole 110 is a through hole processed in the outer wall 11 of the diffuser 1 by a suitable method such as machining.

[0034] Since a relatively closed cavity 10 is formed between the diffuser 1 and the high-pressure rotor 91, the diffuser 1 is a stator component, and the high-pressure rotor 91 is a rotor component. The gas near the wall of the diffuser 1 will remain stationary or rotate at a low speed like the wall of the diffuser 1, while the high-speed rotation of the high-pressure rotor 91 will drive the gas near the wall of the high-pressure rotor to rotate at a high speed, which will cause irregular flow of gas in the cavity 10 between the diffuser 1 and the high-pressure rotor 91, and then cause the temperature in the cavity 10 to continue to rise.

[0035] When the temperature of the gas in the cavity 10 between the diffuser 1 and the high-pressure rotor 91 increases, the wall temperature and temperature gradient of the diffuser 1 near the cavity 10 will increase, thereby reducing the service life of the diffuser 1.

[0036] Since the diffuser 1 decelerates and pressurizes the gas 115 transmitted from the high-pressure compressor 97, the air pressure in the inner cavity 12 of the diffuser is higher than the air pressure in the cavity 10 between the diffuser 1 and the high-pressure rotor 91. Therefore, the gas in the inner cavity 12 of the diffuser will flow into the cavity 10 through the cooling holes 110 to cool the gas in the cavity 10.

[0037] In a specific embodiment, Figure 4 As shown, after the cooling gas in the diffuser cavity 12 enters the cavity 10 through the cooling holes 110, the gas pressure in the cavity 10 will increase accordingly, and then will flow into the gas 115 transmitted from the high-pressure compressor 97, and then return to the diffuser cavity 12 again, forming a circulating cooling system. Thus, a circulating cooling system can be formed in the diffuser 1 through the cooling holes 110.

[0038] By opening a cooling hole 110 in the outer wall 11 of the diffuser 1 near the cavity 10, a portion of the relatively low-temperature cooling gas located in the inner cavity 12 of the diffuser 1 can be introduced into the cavity 10 through the cooling hole 110, thereby reducing the temperature of the gas in the cavity 10, thereby reducing the problem of continuous increase in the temperature in the cavity 10 caused by irregular flow of the gas in the cavity 10. At the same time, the flow of the cooling gas will also generate heat exchange with the wall of the diffuser 1, thereby reducing the wall temperature and temperature gradient of the diffuser 1 near the cavity 10, which can effectively increase the service life of the diffuser.

[0039] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] In some embodiments of the diffuser, a plurality of cooling holes 110 are arranged in the outer wall 11 along the circumference of the outer wall 11. Specifically, as mentioned above, the diffuser 1 is a rotating part structure, and the plurality of cooling holes 110 are arranged along the circumference of the diffuser 1, thereby achieving air bleed at multiple locations in the circumferential direction, ensuring that the diffuser 1 can be evenly cooled in the circumferential direction. Figure 2 In the embodiment shown in , the cooling holes 110 are a group arranged circumferentially along the outer wall 11 , and a group of cooling holes 110 includes a plurality of cooling holes 110 distributed along a whole ring. It can be understood that the cooling holes 110 can also be a plurality of groups.

[0041] In some embodiments of the diffuser, the plurality of cooling holes 110 are evenly distributed along the circumference of the outer wall 11, thereby avoiding the problem that the outer wall 11 of the diffuser 1 is partially cooled insufficiently due to the large distance between the cooling holes 110, thereby preventing the outer wall 11 from being partially cooled and causing a temperature gradient with other areas.

[0042] In some embodiments of the diffuser, the outer side wall 11 has a thickened portion 2 , the thickness of the side wall 11 increases at the thickened portion 2 , and the cooling hole 110 is opened in the thickened portion 2 .

[0043] Further, in some specific embodiments, such as Figure 2 As shown, the thickened portion 2 includes a first convex portion 21 protruding from the outer wall 11 toward the cavity 10 and a second convex portion 22 protruding from the outer wall 11 toward the inner cavity 12 of the diffuser 1. Of course, in some other suitable embodiments, the thickened portion 2 may also include only the first convex portion 21 and the second convex portion 22. By providing the thickened portion 2, the portion where the cooling hole 110 is provided on the outer wall 11 of the diffuser 1 is locally thickened to enhance the strength near the cooling hole 110, thereby increasing the service life of the diffuser. At the same time, by providing the thickened portion 2, the cooling airflow channel is longer when the cooling hole 110 is penetrated, thereby increasing the heat exchange with the outer wall 11 of the diffuser 1 and improving the cooling effect. At the same time, the provision of the thickened portion 2 allows the cooling gas to be sprayed deeper into the cavity 10, which is more conducive to cooling the cavity 10 and further increases the service life of the diffuser.

[0044] In some embodiments of the present diffuser, such as Figure 2 As shown in the details, the cooling hole 110 has an outlet 111 located on the side of the cavity 10 and an inlet 112 located on the side of the inner cavity 12 of the diffuser 1, and the extension direction of the cooling hole 110 from the inlet 112 to the outlet 111 is inclined toward the axis a of the diffuser 1, so that an acute angle is formed between the extension direction and the axis a of the diffuser.

[0045] In some embodiments of the present diffuser, such as Figure 3 In the details shown, the central axis x of the cooling hole 110 is inclined toward the rotation direction y of the high-pressure rotor 91. It should be noted that when the cooling hole is not inclined, the central axis of the cooling hole is approximately perpendicular to the inner and outer wall surfaces of the outer side wall 11, and the central axis of the cooling hole at this time is defined as the first axis. Figure 3 The axis of the cooling hole after tilting is the second axis, and the rotation direction from the first axis to the second axis is the rotation direction of the high-pressure rotor 91, which means that the central axis x of the cooling hole 110 is tilted toward the rotation direction y of the high-pressure rotor 91. Specifically, as shown in the figure, the rotation direction y of the high-pressure rotor 91 is viewed from the heading direction, and rotates clockwise along the engine axis, and then rotates clockwise from the first axis to the second axis.

[0046] By the above arrangement, the central axis x of the cooling hole 110 is inclined toward the direction y of rotation of the high-pressure rotor, which can reduce the relative speed of the gas flowing into the cavity 10 and the original gas in the cavity 10, reduce the heat generated by gas agitation, and further increase the service life of the diffuser.

[0047] In some embodiments of the diffuser, the cooling hole 110 is opened in the middle of the outer wall, so that the cooling airflow is not easily interfered with and can more easily enter the cavity 10 for cooling.

[0048] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "center", "thickness", "up", "down", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientation or position relationship of the connecting component in the connected state. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0049] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] It should be understood that "along" a certain direction mentioned in the text means that there is at least a component in the direction, preferably, the angle with the direction is within 10°, and more preferably, the angle is within 5°.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A diffuser, characterized in that: Used in a combustion chamber of a gas turbine engine, a cavity is formed between the diffuser and the high-pressure rotor of the gas turbine engine; The diffuser has an outer wall, the cavity is surrounded by the outer wall and the high-pressure rotor, a plurality of cooling holes are opened in the outer wall, and each cooling hole connects the cavity with the inner cavity of the diffuser.

2. The diffuser according to claim 1, characterized in that A circulating cooling system is formed on the diffuser through the cooling holes.

3. The diffuser according to claim 1, wherein: A plurality of cooling holes are arranged in the outer wall along the circumference of the outer wall.

4. The diffuser according to claim 1, wherein: The plurality of cooling holes are evenly distributed along the circumference of the outer side wall.

5. The diffuser according to claim 1, wherein: The outer side wall has a thickened portion, the thickness of the side wall increases at the thickened portion, and the cooling hole is opened in the thickened portion.

6. The diffuser according to claim 5, characterized in that The thickened portion includes a first protrusion protruding from the outer side wall toward the cavity and / or a second protrusion protruding from the outer side wall toward the inner cavity of the diffuser.

7. The diffuser according to claim 1, characterized in that The cooling hole has an outlet located on the cavity side and an inlet located on the inner cavity side of the diffuser, and an extension direction of the cooling hole from the inlet to the outlet is inclined toward the axis of the diffuser so that an acute angle is formed between the extension direction and the axis of the diffuser.

8. The diffuser according to claim 1, wherein: The central axis of the cooling hole is inclined toward the rotation direction of the high-pressure rotor.

9. The diffuser according to claim 1, wherein: The cooling hole is opened in the middle of the outer side wall.

10. A gas turbine engine, characterized in that: It comprises a high-pressure rotor and a combustion chamber, wherein the combustion chamber comprises a combustion chamber outer casing and a diffuser, and is characterized in that the diffuser is the diffuser according to any one of claims 1 to 9.

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