CN113883550A

CN113883550A - Low-emission backflow combustion chamber adopting circumferential tangential oil supply mode

Info

Publication number: CN113883550A
Application number: CN202111321874.3A
Authority: CN
Inventors: 曾琦; 朱志新; 王高峰; 郑耀
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2022-01-04
Anticipated expiration: 2041-11-09
Also published as: CN113883550B

Abstract

The invention discloses a low-emission backflow combustion chamber adopting a circumferential tangential oil supply mode, which relates to the technical field of aero-engines and comprises: the fuel nozzle is communicated with the flame tube bent pipe through the beveling premixing swirler. The invention fully utilizes the characteristic that the axial length of the reflow combustion chamber is long and the height of the flame tube cavity is small to carry out fuel oil classification, thereby not only ensuring the flameout characteristic and the transition state characteristic in the limited space of the reflow combustion chamber, but also realizing the low emission of pollutants.

Description

Low-emission backflow combustion chamber adopting circumferential tangential oil supply mode

Technical Field

The invention relates to the technical field of aero-engines, in particular to a low-emission backflow combustion chamber adopting a circumferential tangential oil supply mode.

Background

The combustion chamber is one of the core components of aircraft engines and ground-based gas turbines, and is the "heart" of an aircraft engine and also the site of generation of polluting emissions from the engine. The chemical energy of the kerosene is converted into kinetic energy by the chemical reaction of the aviation kerosene and air in the combustion chamber, a large amount of high-temperature gas is generated at the outlet of the combustion chamber and expands to drive the turbine to do work, along with the development of the aviation industry in recent years and the stricter control and management of environmental pollution at home and abroad, the pollution emission problem of the aero-engine is also valued by the industry, how to improve the performance of the engine, reduce the pollution emission of the engine, and give consideration to the performances such as combustion stability, ignition reliability, structural weight and the like, so that the combustion chamber is a main contradiction required to be solved by the design of the combustion chamber.

At present, the low-pollution design of a combustion chamber in a domestic aeroengine mainly serves the low-emission combustion organization technology of a turbofan engine of a large passenger plane, and the research object of the low-emission combustion organization technology mainly surrounds a central grading low-pollution combustion scheme applicable to a straight-flow annular combustion chamber of the large engine. The method mainly researches key technologies such as flow field, oil-gas mixing and fuel oil grading of different partition ranges of the head of the combustion chamber, and can realize a complex head grading structure only by enough space in the combustion chamber if the space in the flame tube cavity is large enough and the cavity height is more than or equal to 80 mm.

At present, the domestic general aviation industry is rapidly developed, the turboshaft for helicopters and the turboprop for transport machines are important aviation engines, the turboshaft and turboprop have great application in national economy and military national defense, and the pollutant emission of the turboshaft and turboprop is also very important because the using environment of the turboshaft and turboprop is closer to the city than that of a large airplane. For a backflow combustion chamber of a medium-sized and small-sized turboshaft/turboprop engine, due to the characteristics of small flame tube cavity (typically 50mm), large nozzle spacing ratio, low pressure loss and the like of the backflow combustion chamber, a low-pollution combustion scheme of central classification of a turbofan engine is difficult to directly implement.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a low-emission backflow combustor using a circumferential tangential oil supply manner, which adopts an axial staged combustion organization scheme, and fully utilizes the characteristics of the backflow combustor that the axial length is long and the height of a flame tube cavity is small to stage fuel oil, thereby ensuring the point flameout characteristic and the transition state characteristic in a limited backflow combustor space and realizing low emission of pollutants.

In order to achieve the purpose, the invention adopts the technical scheme that:

a low emission reverse flow combustor with circumferential tangential fueling comprising: the fuel nozzle is communicated with the flame tube bent pipe through the beveling premixing swirler.

Preferably, the chamfered premix swirler includes: apron, first order radial blade, second level radial blade and horn type evaporation zone, horn type evaporation zone tail end install in the swirler mount pad, with flame tube return bend intercommunication, the second level radial blade with the first order radial blade, install in proper order in horn type evaporation zone's head end, and with the inside intercommunication of horn type evaporation zone, the apron is arranged in on the first order radial blade.

Preferably, a floating installation seat is further arranged between the first-stage radial blade and the cover plate and used for assembling the fuel nozzle.

Preferably, a plurality of small holes are formed in the horn-shaped evaporation section.

Preferably, the inclined cutting angle between the trumpet-shaped evaporation section and the flame tube head is alpha, and the alpha is 100-170 degrees.

Preferably, a plurality of the chamfered premixing swirlers are annularly distributed on a central line of the flame tube elbow.

Preferably, each of the chamfered premix swirlers is mounted with the fuel nozzle.

Preferably, the swirler mounting seat mounted on the flame tube head is a floating structure.

Preferably, a plurality of air inlets are formed on the flame tube elbow.

Compared with the prior art, the low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode has the following advantages:

the low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode is simple in structure, the radial size of the chamfered premixing swirler is small, an axial grading combustion organization scheme is adopted on the backflow combustion chamber, the characteristic that the axial length of the backflow combustion chamber is long, the height of the flame tube cavity is small is fully utilized to grade fuel, the point flameout characteristic and the transition state characteristic are guaranteed in the limited backflow combustion chamber space, and low emission of pollutants is achieved. And the characteristics that the total pressure ratio of the turboshaft engine is relatively low and the spontaneous combustion and tempering risks caused by lean premixed combustion are low are fully utilized, and the low pollution potential of the technology is fully exerted and the defects of the technology are inhibited by adopting a premixed and pre-evaporated technical route.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a structural cross-sectional view of a circumferential tangential fuel supply low emission reverse flow combustor of the present invention;

FIG. 2 is a schematic view of the layout of the circumferentially chamfered premix swirler of the present invention;

FIG. 3 is a schematic diagram of the construction and operation of the chamfered premix swirler of the present invention.

In the figure: the method comprises the following steps of 1-flame tube elbow, 2-radial diffuser, 3-combustion chamber casing, 4-flame tube head, 5-swirler mounting seat, 6-chamfered premixing swirler, 7-fuel nozzle, 8-floating mounting seat, 9-cover plate, 10-first stage radial blade, 11-second stage radial blade and 12-horn-shaped evaporation section.

Detailed Description

The technical scheme of the invention is further explained by combining the drawings and the embodiment as follows:

1-2, a low emission reverse flow combustor with circumferential tangential fueling, comprising: the burner flame tube comprises a burner flame tube elbow 1, a radial diffuser 2, a combustor casing 3, a burner flame tube head 4, a swirler mounting seat 5, a beveling premixing swirler 6 and a fuel nozzle 7, wherein the radial diffuser 2 is mounted inside the combustor casing 3 from the tail end forward, the burner flame tube elbow 1 is arranged inside the radial diffuser 2, the burner flame tube head 4 is arranged at the head end of the burner flame tube elbow 1, the swirler mounting seat 5 is arranged at the burner flame tube head 4, the beveling premixing swirler 6 is mounted in the swirler mounting seat 5, and the fuel nozzle 7 is communicated with the burner flame tube elbow 1 through the beveling premixing swirler 6.

As shown in fig. 3, the chamfer premix swirler 6 includes: apron 9, first order radial blade 10, second level radial blade 11 and horn type evaporation zone 12, horn type evaporation zone 12 tail end install in swirler mount pad 5, with 1 intercommunication of flame tube return bend, second level radial blade 11 with first level radial blade 10, install in proper order in horn type evaporation zone 12's head end, and with the inside intercommunication of horn type evaporation zone 12, apron 9 is arranged in on the first level radial blade 10.

In a preferred embodiment, a floating mounting seat 8 is further arranged between the first-stage radial blade 10 and the cover plate 9, and the floating mounting seat 8 is used for assembling the fuel nozzle 7.

In a preferred embodiment, the trumpet-shaped evaporation section 12 is provided with a plurality of small holes.

As a preferred embodiment, the oblique cutting angle between the trumpet-shaped evaporation section 12 and the flame tube head 4 is α, the α is 100 to 170 °, and the installation inclination angle is utilized to fully extend the length L of the trumpet-shaped evaporation section 12 of the oblique cutting premix swirler 6 compared with the traditional axial front arrangement, so as to achieve a better effect of reducing pollution emission.

In a preferred embodiment, a plurality of the chamfered premixing swirlers 6 are annularly distributed on the centerline of the flame tube elbow 1.

As a preferred embodiment, each inclined-cut premixing swirler 6 is provided with the fuel nozzle 7, so that the ignition and flame linking performance of the backflow combustion chamber in a small state can be improved, the characteristic that the backflow combustion chamber is long in the axial direction can be fully utilized in a large state, the retention time of an oil-gas mixture in a flame tube is prolonged by utilizing spiral flame propagation, and the purpose of full and efficient combustion is achieved.

In a preferred embodiment, the swirler mount 5 mounted on the flame tube head 4 is a floating structure, which facilitates the insertion mounting of the chamfered premixing swirler 6.

As a preferred embodiment, a plurality of air inlets are formed in the flame tube bent pipe 1, so that an air inlet path in the flame tube bent pipe 1 is increased, air enters a channel between the combustion chamber casing 3 and the flame tube bent pipe 1 through the radial diffuser 2, and enters the flame tube bent pipe 1 through the opening under the action of the pressure difference between the inside and the outside of the flame tube, and the oil-gas mixture is helped to be fully combusted.

The working principle of the invention is as follows:

when the device works, air enters a channel between a combustion chamber casing 3 and a flame tube bent pipe 1 through a radial diffuser 2, the air enters a cavity of the flame tube bent pipe 1 from openings on a head premixing swirler 6 and the flame tube bent pipe 1 under the action of the internal and external pressure difference of the flame tube bent pipe 1, the air passing through the blades forms cyclone air through a first-stage radial blade 10 and a second-stage radial blade 11, the cyclone air passing through the blades is mixed with atomized fuel oil sprayed by a working nozzle to form an oil-gas mixture, the oil-gas mixture passes through a horn-shaped evaporation section 12 and enters along with small holes of the horn-shaped evaporation section 12 to further fully mix and evaporate oil mist, the oblique cutting angle alpha is usually between 100 and 170 degrees, and compared with the traditional axial front arrangement, the installation inclination angle can fully prolong the length L of the horn-shaped evaporation section 12 of the oblique cutting swirler 6, therefore, the effect of reducing pollution emission is better achieved, the oil-gas mixture is ignited and combusted through the ignition fuel nozzle 7 in the flame tube bent pipe 1, and the oil-gas mixture is ignited in the flame tube bent pipe 1 when meeting flame to quickly form high-temperature fuel gas and is discharged out of the flame tube along the flame tube bent pipe 1.

In the present specification, the apparatuses disclosed in the embodiments correspond to the methods disclosed in the embodiments, so the description is relatively simple, and the relevant points can be referred to the method part for description. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 low emission reverse flow combustor employing circumferential tangential fueling, comprising: flame tube return bend (1), radial diffuser (2), combustion chamber machine casket (3), flame tube head (4), swirler mount pad (5), chamfer premix swirler (6) and fuel nozzle (7), radial diffuser (2) from the tail end install forward inside combustion chamber machine casket (3), flame tube return bend (1) is arranged in inside radial diffuser (2), the head end of flame tube return bend (1) is equipped with flame tube head (4), flame tube head (4) are equipped with swirler mount pad (5), chamfer premix swirler (6) install in swirler mount pad (5), fuel nozzle (7) pass through chamfer swirler (6) with flame tube return bend (1) intercommunication.

2. A low emission reverse flow combustor with circumferential tangential oil supply as claimed in claim 1, wherein the chamfered premix swirler (6) comprises: apron (9), first order radial blade (10), second level radial blade (11) and horn type evaporation zone (12), horn type evaporation zone (12) tail end install in swirler mount pad (5), with flame tube return bend (1) intercommunication, second level radial blade (11) with first level radial blade (10), install in proper order in the head end of horn type evaporation zone (12), and with horn type evaporation zone (12) inside intercommunication, apron (9) are arranged in on the first level radial blade (10).

3. The low-emission backflow combustion chamber with circumferential tangential oil supply of claim 2, wherein a floating mounting seat (8) is further arranged between the first-stage radial blade (10) and the cover plate (9), and the floating mounting seat (8) is used for assembling the fuel nozzle (7).

4. The low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode as claimed in claim 2, wherein a plurality of small holes are formed in the trumpet-shaped evaporation section (12).

5. The low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode as claimed in claim 2, wherein the chamfer angle of the trumpet-shaped evaporation section (12) and the flame tube head (4) is alpha, and the alpha is 100-170 degrees.

6. The low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode as claimed in claim 1, wherein a plurality of the chamfered premixing swirlers (6) are annularly distributed on the central line of the flame tube elbow (1).

7. A low emission reverse flow combustor with circumferential tangential fuel supply as claimed in claim 6 wherein each of said chamfered premixer swirler (6) has said fuel injector (7) mounted thereon.

8. The low emission reverse flow combustor with circumferential tangential oil supply of claim 1, wherein the swirler mount (5) mounted to the liner head (4) is a floating structure.

9. The low-emission backflow combustion chamber adopting the circumferential tangential oil supply mode as claimed in claim 1, wherein a plurality of air inlet holes are formed on the flame tube elbow (1).