A multi-stage central staging wide field stable combustor head

Abstract

The application discloses a multi-stage center grading wide-range stable combustion chamber head, and relates to the technical field of combustion chambers. The multi-stage center grading wide-range stable combustion chamber head comprises a head outer ring shell, a second main combustion stage assembly, a first main combustion stage assembly and a plurality of xth main combustion stage assemblies. The second main combustion stage assembly comprises a second fuel supply cavity and second swirl vanes, and the second swirl vanes are provided with second fuel injection holes which are communicated with the second fuel supply cavity. The first main combustion stage assembly comprises a first fuel supply ring cavity and first swirl vanes, and the first swirl vanes are provided with first fuel injection holes which are communicated with the first fuel supply ring cavity. Each main combustion stage assembly comprises a fuel supply cavity and swirl vanes, and the form is the same as that of the second main combustion stage. The head outer ring shell is arranged for installation, positioning and forming a flow channel. The xth main combustion stage assembly, the second main combustion stage assembly and the first main combustion stage assembly are arranged, and the straight-flow air is changed into swirl flow by the swirl vanes. The fuel is injected out from the first fuel injection holes and the second fuel injection holes after entering the head outer ring shell from the outside.

Description

Technical Field

[0001] This invention relates to the field of combustion chamber technology, and more specifically to a multi-stage, centrally graded, wide-range stable combustion chamber head. Background Technology

[0002] A key development trend in the thrust performance of gas turbine engines is to increase thrust per unit volume by improving combustion chamber temperature rise. Therefore, future advanced engines will have extremely high air-fuel ratios in their combustion chambers at maximum thrust, while maintaining extremely low air-fuel ratios for stable combustion in lean-burn conditions at idle. This necessitates maintaining efficient and stable combustion across multiple operating conditions over a very wide operating range.

[0003] The currently widely adopted combustion chamber head fuel-air mixing and combustion organization method is central grading. Air and fuel are radially graded with the axis of each swirl head of the annular combustion chamber as the center. The fuel is divided into two stages: the inner pre-combustion stage and the outer main combustion stage. Correspondingly, the air is also divided into the main pre-combustion stage and its fuel are mixed and burned separately. Limited by structural and technological factors, the main combustion stage fuel is usually injected through direct-injection nozzles in the main combustion stage swirling air passage, and then mixed with a large amount of main combustion stage air before combustion. The pre-combustion stage fuel is injected in a hollow mist cone manner using centrifugal nozzles or air atomizing nozzles. Its flow rate is small, and it burns stably in the recirculation zone formed by a small amount of pre-combustion stage swirling air. Its functions are: 1) When the pre-combustion stage burns alone, the total fuel-air ratio in the combustion chamber is low, which can meet the overall aerodynamic and thermodynamic needs of the engine under lower operating conditions such as idle speed. In the area controlled by the pre-combustion stage air, the fuel-air ratio is high, which can ensure stable combustion; 2) Under higher operating conditions, when the main and pre-combustion stages burn simultaneously, the pre-combustion stage flame provides a continuous ignition effect on the fuel-air mixture of the main combustion stage, so that the entire combustion chamber works stably.

[0004] To meet the requirements of future aero-engines for combustion chambers, such as ultra-high temperature rise, ultra-high fuel-air ratio, and extremely wide stable operating range, it is necessary to complete the research on a new staged swirling combustion aero-thermodynamic scheme and propose an innovative combustion chamber head structure to support the development of a wide-range stable combustion chamber for engines.

[0005] 1. High-temperature rise and wide-range stable combustion chambers require an extremely low proportion of wall-cooled air to increase the amount of air participating in combustion and achieve high turbine inlet temperatures. They also require rapid, complete, and uniform combustion in the combustion zone to avoid hot-spot ablation of hot-end components. Simultaneously, shortening the combustion chamber length achieves weight reduction benefits to meet the engine's high thrust-to-weight ratio requirements. Conventional combustion chamber head fuel staging only has two stages: the main combustion stage fuel injection scheme is a single-stage injection with the injection point close to the inner side of the premixing channel annular cavity. This single-stage fuel jet is difficult to mix with a large amount of air to form a homogeneous mixture for efficient combustion, affecting combustion chamber performance.

[0006] 2. Current research indicates that while the combustion chamber head features 2-4 air stages (1-2 stages each for the main and pre-combustion stages) to enhance fuel fragmentation, evaporation, and mixing in the swirling air, thus optimizing combustion organization, the actual combustion chamber design point is limited to only two stages due to the limited fuel grading. Fuel atomization and air-fuel matching at the combustion chamber head are only optimal under high-flow, high-operational-condition conditions (such as engine takeoff). Under lower-flow, intermediate-condition conditions (such as engine cruise) where the main combustion stage is activated, deviations from the design parameters will lead to deteriorated air-fuel mixing and reduced combustion performance at the combustion chamber head.

[0007] Therefore, how to provide a multi-stage, centrally graded, wide-range stable combustion chamber head that improves the freedom of fuel-air mixing in the combustion chamber head, facilitates the distribution of fuel concentration for combustion, and enables multiple efficient operations of the combustion chamber and engine is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the present invention provides a multi-stage, centrally graded, wide-range stable combustion chamber head, which aims to solve one of the problems in the above-mentioned background technology, improve the degree of freedom of fuel-air mixing in the head, facilitate the distribution of fuel concentration during combustion, and enable multiple efficient operations of the combustion chamber and engine.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A multi-stage, centrally graded, wide-range stable combustion chamber head includes:

[0011] 1. A multi-stage, centrally graded, wide-range stable combustion chamber head, characterized in that it comprises:

[0012] Head outer ring shell;

[0013] The second main combustion stage assembly includes a second fuel supply chamber and a second swirl vane. The second fuel supply chamber and the second swirl vane are both disposed inside the outer ring housing of the head. The second swirl vane is provided with a second fuel injection hole, which communicates with the second fuel supply chamber. The second swirl vane forms the air flow channel of the second main combustion stage.

[0014] The first main combustion stage assembly includes a first fuel supply ring cavity and a first swirl vane. The first fuel supply ring cavity and the first swirl vane are both disposed within the outer ring housing of the head, and the first fuel supply ring cavity and the first swirl vane are disposed inside the second main combustion stage assembly. The first swirl vane is provided with a first fuel injection hole, which communicates with the first fuel supply ring cavity. The first swirl vane forms the first main combustion stage airflow channel.

[0015] Furthermore, it also includes an inner baffle of the main combustion stage, with the second fuel supply chamber disposed inside the inner baffle of the main combustion stage, and the inner baffle of the main combustion stage is used to separate the first main combustion stage flow channel and the second main combustion stage flow channel.

[0016] Furthermore, it also includes the xth main combustion stage assembly, which has the same structure as the second main combustion stage assembly. Both are located inside the outer ring housing of the head and outside the second main combustion stage assembly. The fuel supply chamber of the xth main combustion stage is located inside the inner partition of the xth main combustion stage. The inner partition of the xth main combustion stage is used to separate the flow channel of the xth main combustion stage and the air flow channel of the (x-1)th main combustion stage.

[0017] Furthermore, it also includes a pre-combustion swirl vane and a pre-combustion fuel nozzle, wherein the pre-combustion swirl vane and the pre-combustion fuel nozzle are disposed within the outer ring housing of the head, the pre-combustion swirl vane is disposed inside the first main combustion stage flow channel, and the pre-combustion fuel nozzle is configured as a hollow cone.

[0018] Furthermore, it also includes a head cooling airflow channel, which is disposed within the outer ring housing of the head.

[0019] Furthermore, it also includes a premixed channel annular cavity, which is an annular flow channel downstream of each of the main combustion stage components.

[0020] Furthermore, both the first and second swirl blades are hollow structures.

[0021] Furthermore, the arrangement of the main combustion stage components is a centrally graded arrangement with radial stacking outwards.

[0022] Furthermore, each of the main combustion stages employs a bladed swirl flow. The bladed swirl flow employed in each main combustion stage includes blades in any direction, including but not limited to axial and radial blades.

[0023] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method that provides a method by setting an outer ring shell for mounting, positioning and forming a flow channel; by setting x main combustion stage components, whose swirl blades convert the direct incoming airflow into a swirling flow, and the fuel is injected from the fuel injection holes on the blades of each stage after passing through the fuel supply chambers of each stage.

[0024] During the design phase, by setting x main combustion stage components, variables were added, providing more design freedom for head gas-fuel mixing. This allows for more detailed optimization and control of fuel injection, evaporation, and mixing in different areas, achieving the most favorable fuel concentration distribution for combustion under different operating conditions, and enabling multiple design points for efficient operation of the combustion chamber and engine.

[0025] During the application phase, because the combustion chamber has multiple main combustion stages operating stably, the engine can have multiple long-term high-efficiency operating states, which facilitates engine control and can improve the performance of the engine in various states compared to traditional designs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 The cross-sectional view of the head of a multi-stage, centrally graded, wide-area stable combustion chamber with x=2 is provided by the present invention, taking a two-stage axial swirl main combustion stage as an example.

[0028] Figure 2 The present invention provides an axial upstream view of the head of a multi-stage centrally graded wide-area stable combustion chamber with x=2, taking a two-stage axial swirl main combustion stage as an example.

[0029] Wherein: 1 is the outer ring shell of the head; 2 is the second fuel supply chamber; 3 is the second swirl vane; 4 is the second fuel injection hole; 5 is the first fuel supply ring cavity; 6 is the first swirl vane; 7 is the first fuel injection hole; 8 is the main combustion stage inner partition; 9 is the pre-combustion swirl vane; 10 is the pre-combustion fuel nozzle; 11 is the head cooling airflow channel; 12 is the premixing channel ring cavity. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Taking a two-stage axial swirl main combustion stage as an example, i.e., x = 2, see [link / reference]. Figure 1-2 This invention discloses a multi-stage, center-level, wide-range stable combustion chamber head, comprising:

[0032] Head outer ring housing 1; Head outer ring housing 1 is an integral structure, and head outer ring housing 1 is used for installation, positioning and forming flow channels;

[0033] The second main combustion stage assembly includes a second fuel supply chamber 2 and a second swirl vane 3. Both the second fuel supply chamber 2 and the second swirl vane 3 are disposed within the head outer ring housing 1. The second swirl vane 3 is provided with a second fuel injection hole 4, which is connected to the second fuel supply chamber 2. The second swirl vane 3 forms the air flow channel of the second main combustion stage. By setting the second swirl vane 3, the direct incoming airflow is transformed into a swirling flow, and the fuel is injected from the second fuel injection hole 4 after passing through the second fuel supply chamber 2.

[0034] The first main combustion stage assembly includes a first fuel supply ring cavity 5 and a first swirl vane 6. Both the first fuel supply ring cavity 5 and the first swirl vane 6 are disposed inside the head outer ring housing 1, and the first fuel supply ring cavity 5 and the first swirl vane 6 are disposed inside the second main combustion stage assembly. The first swirl vane 6 is provided with a first fuel injection hole 7, which is connected to the first fuel supply ring cavity 5. The first swirl vane 6 forms the first main combustion stage air flow channel. By setting the first swirl vane 6, the direct incoming airflow is transformed into a swirling flow, and the fuel is injected from the first fuel injection hole 7 after passing through the first fuel supply ring cavity 5.

[0035] In this embodiment, a main combustion stage inner partition 8 is also included. The second fuel supply chamber 2 is disposed inside the main combustion stage inner partition 8. The main combustion stage inner partition 8 is used to separate the first main combustion stage flow channel and the second main combustion stage flow channel. Each stage of fuel and air are first injected and mixed independently in each stage of the flow channel inside and outside the main combustion stage inner partition 8.

[0036] It also includes the xth main combustion stage assembly, which has the same structure as the second main combustion stage assembly. Both are located inside the head outer ring housing 1 and outside the second main combustion stage assembly. The fuel supply chamber of the xth main combustion stage is located inside the inner baffle of the xth main combustion stage. The inner baffle of the xth main combustion stage is used to separate the flow channel of the xth main combustion stage and the air flow channel of the x-1th main combustion stage.

[0037] In this embodiment, it also includes a pre-combustion swirl vane 9 and a pre-combustion fuel nozzle 10. The pre-combustion swirl vane 9 and the pre-combustion fuel nozzle 10 are disposed inside the outer ring housing 1 of the head. The pre-combustion swirl vane 9 is disposed inside the first main combustion stage flow channel, and the pre-combustion fuel nozzle 10 is configured as a hollow cone. The pre-combustion stage fuel is sprayed out in a hollow mist cone manner using a centrifugal nozzle or an air atomizing nozzle. Its flow rate is small, and it burns stably in the recirculation zone formed by a small amount of pre-combustion stage swirl air. The pre-combustion stage flame forms a continuous ignition effect on the main combustion stage fuel-air mixture, so that the entire combustion chamber works stably. The first main combustion stage assembly, the second main combustion stage assembly, the pre-combustion swirl vane 9, and the pre-combustion fuel nozzle 10 together constitute the complete combustion chamber head of the present invention.

[0038] In this embodiment, a head cooling airflow channel 11 is also included, which is disposed inside the head outer ring shell 1; the head cooling airflow channel 11 is used to cool the inside of the head outer ring shell 1.

[0039] In this embodiment, a premixed channel annular cavity 12 is also included. The premixed channel annular cavity 12 is an annular flow channel downstream of each main combustion stage. After each stage of fuel and air are independently injected and mixed in the flow channels inside and outside the main combustion stage inner baffle 8, they enter the premixed channel annular cavity 12. In the premixed channel annular cavity 12, there is no separation of the main combustion stage inner baffle 8, and each stage of fuel and air mixture is further mixed with each other until the fuel vapor is evenly distributed in the air.

[0040] In this embodiment, both the first swirl blade 6 and the second swirl blade 3 are hollow structures.

[0041] In this embodiment, the main combustion stage components are arranged in a centrally graded manner and then stacked radially outwards.

[0042] In this embodiment, each main combustion stage adopts a blade-type swirl flow.

[0043] In this embodiment, the main combustion stage fuel injection method is side injection from the first swirl vane 6 and the second swirl vane 3, with the first swirl vane 6 and the second swirl vane 3 injecting alternately. The first swirl vane 6, the second swirl vane 3, and the pre-combustion stage swirl vane have the same swirl direction.

[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-stage, centrally-staged, wide-field stable combustor head, characterized by, The application relates to a turbine head assembly. The turbine head assembly comprises a head outer ring shell, a second main combustion stage assembly, a first main combustion stage assembly, a precombustion swirl vane, a precombustion fuel nozzle, a head cooling air flow channel, a premixing channel ring cavity, a plurality of main combustion stage assemblies, and a main combustion stage inner partition plate. The second main combustion stage assembly comprises a second fuel supply cavity and a second swirl vane, both of which are arranged in the head outer ring shell, the second swirl vane is provided with a second fuel injection hole, the second fuel injection hole is communicated with the second fuel supply cavity, and the second swirl vane forms a second main combustion stage air flow channel. The straight-flow incoming air is changed into swirl air by arranging the second swirl vane, and fuel is sprayed out from the second fuel injection hole after passing through the second fuel supply cavity. The first main combustion stage assembly comprises a first fuel supply ring cavity and a first swirl vane, both of which are arranged in the head outer ring shell, the first fuel supply ring cavity and the first swirl vane are arranged inside the second main combustion stage assembly, the first swirl vane is provided with a first fuel injection hole, the first fuel injection hole is communicated with the first fuel supply ring cavity, and the first swirl vane forms a first main combustion stage air flow channel. The straight-flow incoming air is changed into swirl air by arranging the first swirl vane, and fuel is sprayed out from the first fuel injection hole after passing through the first fuel supply ring cavity. The second fuel supply cavity is arranged inside the main combustion stage inner partition plate, and the main combustion stage inner partition plate is used for separating the first main combustion stage air flow channel and the second main combustion stage air flow channel.

2. A multi-stage central staged wide field stable combustor head according to claim 1, wherein, The xth main combustion stage assembly has the same structure as the second main combustion stage assembly, is arranged in the head outer ring shell outside the second main combustion stage assembly, the fuel supply cavity of the xth main combustion stage is arranged inside the xth main combustion stage inner partition plate, and the xth main combustion stage inner partition plate is used for separating the xth main combustion stage air flow channel and the x-1th main combustion stage air flow channel.

3. A multi-stage central staged wide field stable combustor head according to claim 1, wherein, The precombustion swirl vane and the precombustion fuel nozzle are arranged in the head outer ring shell, the precombustion swirl vane is arranged inside the first main combustion stage air flow channel, and the precombustion fuel nozzle is arranged in a hollow conical shape.

4. A multi-stage central staged wide field stable combustor head according to claim 1, wherein, The head cooling air flow channel is arranged in the head outer ring shell.

5. A multi-stage central staged wide field stable combustor head according to claim 1, wherein The premixing channel ring cavity is an annular flow channel downstream of each main combustion stage assembly.

6. A multi-stage central staged wide field stable combustor head according to claim 5, wherein, The first swirl vane and the second swirl vane are both hollow structures.

7. A multi-stage central staged wide field stable combustor head according to claim 1, wherein The arrangement mode of the plurality of main combustion stage assemblies is center grading and outward radial superposition. Each main combustion stage adopts a vane type swirl.

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