CN106482154A - The lean premixed preevaporated low contamination combustion chamber that a kind of main is atomized with splashing type - Google Patents

Abstract

The invention discloses a lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization on the main stage, comprising a diffuser and a casing; a combustion chamber head and a combustion chamber head are arranged inside the casing. The connected flame tube, the head of the combustion chamber is divided into two parts, the duty level and the main level; the main level surrounds the outer ring of the duty level; There are two-stage axial swirlers and three-stage axial swirlers; the present invention adopts the diffusion combustion mode through the duty stage, the main stage adopts the lean fuel premixed pre-evaporation combustion mode, and adopts multi-point fuel direct injection atomization and The spray atomization effect combined with liquid film atomization can form a uniform combustion flame and reduce the flame temperature, thereby greatly reducing the emission of pollutants such as NOx, UHC, CO and smoke. The main stage converges the throat And the design of the premixed chamber can effectively prevent the occurrence of spontaneous combustion and tempering.

Description

A lean-oil premixed pre-evaporation low-pollution combustor with main stage spray atomization

technical field

The invention belongs to the field of aero-engines, and mainly relates to a fuel-lean premixed pre-evaporation low-pollution combustion chamber with splash atomization in the main stage.

Background technique

At present, civil aviation engines emit more and more pollutants into the atmosphere, and the air pollution is also becoming more and more serious. In order to control the impact of aircraft engine emissions on the environment, the International Civil Aviation Organization promulgated the "Environmental Protection Standards" and "Aero Engine Emissions" regulations in the 1980s, and continuously revised and improved them. At present, it has begun to implement the CAEP6 emission standards, especially for NOx Emissions requirements are getting stricter. In order to meet the CAEP6 standard, major aero-engine companies and research institutions are conducting research on low-pollution combustion technologies. The combustor developed by GE adopts the latest Twin Annular Premixing Swirler (TAPS) combustor technology, which has been used in the Leap-X engine, and its NOx pollutant emission is 47.7% lower than that of CAEP6. Pratt & Whitney developed the TALON X combustion chamber using RQL combustion technology, which is used on the PW1000G engine, and its NOx pollutant emission is 40% lower than that of CAEP6.

The main combustion chamber of traditional military aircraft adopts diffusion combustion. Under 100% working conditions, the oil-gas ratio in the main combustion zone is designed for a chemically appropriate oil-gas ratio, and the combustion efficiency is high. However, the temperature of the gas in the main combustion zone is very high, so a large amount of thermal energy will be generated. NOx; while in slow running conditions, the combustion efficiency is low and the combustion is incomplete, so the pollutants CO and UHC are generated more. Therefore, the conventional diffusion combustion method is difficult to meet the current or future low pollution emission requirements. At present, lean oil premixed pre-evaporative combustion technology has been used in low-pollution combustors. The existing combustor combustion technology can reduce pollutant NOx emissions to a certain extent, but the performance of the combustor cannot be guaranteed. Therefore, a The new type of combustion chamber, while ensuring the stable operation of the combustion chamber, can also ensure a uniform combustion flame and reduce the emission of pollutants such as NOx, UHC, CO and smoke to the greatest extent. It has always been a technology to be solved by those skilled in the art. problem.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a lean oil premixed pre-evaporation low-pollution combustion chamber with splash atomization on the main stage. The duty stage enters the head of the combustion chamber; the duty stage uses small flow pressure atomizing nozzles for diffusion combustion, while the main stage performs partial premixing and pre-evaporation combustion, so as to ensure the performance of the combustion chamber and reduce pollutant emissions.

The present invention is achieved in this way, a lean oil premixed pre-evaporation low-pollution combustion chamber with splash atomization in the main stage, including a diffuser and a casing connected to the diffuser; the inside of the casing is provided with a combustion chamber The head of the combustion chamber, the flame tube connected to the head of the combustion chamber, and the fuel injection rod are inserted into the casing and connected to the head of the combustion chamber. Two parts of the stage; the main stage surrounds the outer ring of the duty stage; the main stage includes the secondary axial cyclone, the tertiary axial cyclone, the secondary axial cyclone and the tertiary shaft To the tongue between the swirlers, the premix chamber behind the tongue, and the converging throat behind the premix chamber; the converging throat is at the outlet of the premix chamber; through the mixing of oil and gas in the premix chamber Uniform, premixed and pre-evaporated uniform combustion flame is formed at the exit of the main-stage converging throat, which reduces the flame temperature, thereby reducing the emission of pollutants such as NOx, UHC, CO and smoke to a large extent. The main-stage converging throat and pre-mixing The cavity design can effectively prevent the occurrence of spontaneous combustion and tempering; the main stage is provided with multi-point fuel direct injection holes, and the position is opposite to the tongue.

Further, the combustion inner ring channel and the combustion outer ring channel are arranged between the flame tube and the casing; the combustion inner ring channel and the combustion outer ring channel are designed according to the air flow distribution law;

Further, the duty class includes a first-stage axial cyclone, a convergent section, a throat, and an expansion section that are sequentially connected to the first-stage axial cyclone; the design of the expansion section can not only solve the problem of carbon deposition at the head, but also Ensure that the downstream of the duty class forms a duty recirculation area that is conducive to ignition and flame stability; the roar design can solve the problems of backfire and nozzle carbon deposition in the duty class;

Further, the oil spray rod is provided with dual oil pipelines of a centrifugal nozzle on duty and a main-stage oil supply pipe; the centrifugal nozzle on duty is located at the center of the first-stage axial swirler in the duty class; The main stage oil supply pipe is connected to the main stage through the oil collecting chamber; the setting of the double oil pipe makes the oil pass through the main stage oil supply pipe on the one hand, and then enters the inside of the flame tube through the main stage; The duty-grade centrifugal nozzle inside the oil rod then enters the inside of the flame tube.

Further, the main stage is sequentially connected with the oil injection rod through the oil collecting chamber and the main stage oil supply pipe. Further, axial swirl vanes are installed in the first-stage axial swirler, the second-stage axial swirler and the third-stage axial swirler.

Further, the blade installation angle of the secondary axial cyclone is opposite to that of the primary axial cyclone; the blade installation angle of the third-stage axial cyclone is opposite to that of the secondary axial cyclone The installation angle of the vane of the flow device is the same or opposite.

Further, the duty stage is connected to the main stage through the head inner ring cooling assembly; the main stage is connected to the flame tube through the head outer ring cooling assembly.

Further, the head inner ring cooling assembly is provided with head cooling small holes, and the head inner ring splash plate is connected to the front of the head inner ring cooling assembly; the head outer ring cooling assembly A small hole for cooling the outer ring of the head is provided on the upper part, and a splash plate of the outer ring of the head is connected to the front part of the cooling assembly of the outer head ring.

Further, the connection method is to connect each other by welding or bolts.

The beneficial effects of the present invention and prior art are:

(1) In the present invention, the air and fuel are classified. The duty class in the present invention adopts the diffusion combustion mode, which can ensure the stable operation of the combustion chamber. The on-duty recirculation area is helpful for ignition and flame stability; the roar design can solve the problems of backfire and nozzle carbon deposition in the on-duty class;

(2) Secondly, the main stage of the present invention adopts lean fuel premixed pre-evaporative combustion technology, and adopts the spray atomization effect of the combination of multi-point fuel direct injection atomization and liquid film atomization, and double The aerodynamic atomization effect is further formed under the condition of stage swirl air intake, and the oil and gas are evenly mixed in the premixing chamber to form a premixed pre-evaporative combustion or semi-premixed pre-evaporative combustion mode, and a premixed gas is formed at the outlet of the main stage converging throat. Pre-evaporation evenly burns the flame and reduces the flame temperature, thereby greatly reducing the emission of pollutants such as NOx, UHC, CO, and smoke. The design of the main-stage convergent throat and the pre-mixing chamber can effectively prevent the occurrence of spontaneous combustion and backfire .

Description of drawings

Fig. 1 is a schematic structural view of a lean oil premixed pre-evaporation low-pollution combustor with a main stage spray atomization of the present invention;

Fig. 2 is a schematic diagram of the head structure of a lean-oil premixed pre-evaporation low-pollution combustor with main stage spray atomization of the present invention.

Among them, 1-duty level, 2-main level, 3-head inner ring cooling assembly, 4-head outer ring cooling assembly, 5-flame tube, 6-casing, 7-fuel injection rod, 8-level one Axial cyclone, 9-converging section, 10-throat, 11-expansion section, 12-secondary axial cyclone, 13-third-stage axial cyclone, 14-tongue, 15-premixing Cavity, 16-convergent throat, 17-cooling holes in the outer ring of the head, 18-splash plate of the outer ring of the head, 19-duty level centrifugal nozzle, 20-main oil supply pipe, 21-oil collection chamber, 22 -Multi-point fuel direct injection holes, 23-cooling holes in the inner ring of the head, 24-splash plate of the inner ring of the head, 25-diffuser, 26-combustor inner ring channel, 27-combustor outer ring channel, 28 - Combustion chamber head.

detailed description

The present invention provides a kind of lean oil pre-mixed pre-evaporation low-pollution combustor with splash atomization in the main stage. Detailed description. It should be pointed out that the specific implementations described here are only used to explain the present invention, not to limit the present invention.

The working process of the main stage spray atomization effect of the combustion chamber of the present invention is as follows: after the air from the high-pressure compressor enters the combustion chamber from the diffuser 25, it is divided into three paths and enters the combustion chamber ring channel 27 and the combustion chamber respectively. Head 28, combustion outer ring passage 26. Combustor head 28 includes duty stage 1 and main stage 2 . In the main stage 2, the fuel (accounting for 40% to 95% of the total fuel volume) is sprayed out through the multi-point fuel direct-injection nozzle 22 and initially atomized, and is subjected to the air flow from the secondary axial swirler 12 of the main stage. The impact breaks to form secondary aerodynamic atomization, and then the fuel sprays onto the tongue 14 to form an oil film, and moves forward along the tongue. The shearing and crushing of the airflow at the outlet of the device 13 carries out three times of atomization, and then enters the premixing chamber 15. The fuel and air continue to atomize and evaporate in the premixing chamber 15 and mix with the air evenly before entering the combustion zone to form a premixed pre-evaporation combustion Or semi-premixed pre-evaporative combustion. The spray atomization effect of the main stage 2 can be adjusted by adjusting the injection angle of the main stage multi-point fuel direct injection nozzle hole 22 and the fuel supply pressure of the main stage fuel supply pipe 20, as follows:

The combustion chamber of the present invention comprises a diffuser 25, a combustion chamber head 28, a flame tube 5, an inner ring passage 26 in the combustion chamber, an outer ring passage 27 in the combustion chamber, a fuel injection rod 7 and a casing 6, and the fuel injection rod 7 is installed on On the casing 6, the combustion chamber head 28 is connected to the casing 6 through the fuel injection rod (7). Between the flame tube 5 and the casing 6, there are a combustion inner ring channel 27 and a combustion outer ring channel 26. The channel 26 and the combustion outer ring channel 27 are designed according to the air flow distribution law. The fuel injection rod 7 is a dual oil pipeline equipped with a duty-level centrifugal nozzle 19 and a main-level oil supply pipe 20. The duty-level centrifugal nozzle 19 is located at In the middle of the first-stage axial swirler 8 in the duty class 1; the main stage 2 is connected to the fuel injection rod 7 through the oil collection chamber 21 and the main-stage oil supply pipe 20 in turn, and the combustion chamber head 28 is a circular double ring The cavity structure is divided into two parts: duty level 1 and main level 2, and the main level 2 is the outer ring surrounding duty level 1. The duty class 1 includes a primary axial swirler 8, a converging section 9, a throat 10, and an expansion section 11. Axial swirl blades are installed in the primary axial swirler 8, and are connected with the primary axial swirl. The converging section 9, the throat 10, and the expansion section 11 connected in turn by the flow device 8, and the first-stage axial swirler 8 surround the outside of the centrifugal nozzle 19 on duty. The main stage 2 includes a secondary axial swirler 12, a tertiary axial swirler 13, a tongue 14, a premix chamber 15, a converging throat 16, a main stage oil supply pipe 20, an oil collection chamber 21 and a multi-point Fuel direct injection nozzle 22, a tongue 14 is arranged between the secondary axial swirler 12 and the third axial swirler 13, a premixing chamber 15 is arranged behind the tongue 14, and a premixing chamber 15 is arranged behind the premixing chamber 15 Convergent throat 16; said converging throat 16 is at the exit position of premix chamber 15; axial swirl vanes are installed in the secondary axial swirler 12 and the tertiary axial swirler 12, and the multi-point The fuel injection hole 22 is arranged under the tongue 14 , the premix chamber 15 is arranged behind the tongue 14 , and the converging throat 16 is arranged at the outlet of the premix chamber 15 .

The head inner ring cooling assembly 3 is arranged between the duty class 1 and the main stage 2, the air enters through the head cooling holes 23 on the head inner ring cooling assembly 3, and the splash plate 24 of the head inner ring is cooled. Impingement cooling, and the head outer ring cooling assembly 4 is arranged between the main stage 2 and the flame tube 5, and the head outer ring cooling small hole 17 of air enters to perform impingement cooling on the head outer ring splash plate 18.

The blades and tongues 14 of the secondary axial swirler 12 of the main stage, and the blades of the third-stage axial swirler 13 are formed by integral machining, integral casting or welding, and the oil collection chamber 21 is connected with the main The secondary axial swirlers 12 of the stage can be connected to each other by welding, the head outer ring splash plate 18 and the head outer ring cooling assembly 4 are connected by welding or bolts, and the main stage 2 and the head outer ring cooling assembly 4 are connected by The head inner ring cooling assembly 3 and the main stage 2 are connected to each other by welding or bolts, the head inner ring splash plate 24 and the head inner ring cooling assembly 3 are connected to each other by welding or bolts, and the head inner ring cooling assembly 3 is connected to each other by welding or bolts. The ring cooling assembly 3 is connected to the duty level 1 by welding or bolting.

The multi-point fuel direct injection nozzles 22 are evenly arranged on the ring, and the quantity, injection angle and the fuel supply pressure of the main stage fuel supply pipe 20 can be adjusted according to the required working state and the secondary axial rotation of the main stage. The number of blades of the diffuser 12 is determined. The number of multi-point fuel direct-injection nozzles 22 evenly arranged on the ring is 6-36. Between, the oil supply pressure of the main stage oil supply pipe 20 is between 0.1MPa～4MPa, by designing the oil supply pressure of the main stage oil supply pipe 20, the fuel injected from the multi-point fuel direct injection nozzle hole 22 can be injected to Tongue 14, so as to form a liquid film atomization, and under the joint action of the main stage two-stage swirl aerodynamic atomization, so that the main stage 2 splash atomization effect is optimized, and the oil and gas in the premixing chamber 15 are mixed more uniform.

The blade installation angle of the first-stage axial swirler 8 on duty level 1 is between 20° and 65°, the number of blades is between 6 and 20, and the rotation direction of the blades of the first-stage axial swirler is along the airflow direction It can be counterclockwise or clockwise; the blade installation angle of the secondary axial swirler 12 of the main stage is between 20° and 60°, the number of blades is between 8 and 24, and the three-stage axial swirl The blade installation angle of the device 13 is between 30° and 60°, and the number of blades is between 10 and 40 pieces. the same or the opposite.

The angle between the converging section 9 of the duty class and the centerline X is between 30° and 60°, and the angle between the expansion section 11 and the centerline X is between 30° and 75°.

The air at the head 28 of the combustion chamber accounts for 50% to 85% of the total air volume at the inlet of the combustion chamber, wherein the duty level 1 accounts for 20% to 50% of the air volume at the head, and the main level 2 accounts for 50% of the air volume at the head ~80%.

The above descriptions are only preferred feasible embodiments of the present invention, and do not limit the patent scope of the present invention. Therefore, all equivalent changes made by using the description and drawings of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A lean oil premixed pre-evaporation low-pollution combustion chamber with splash atomization in the main stage, including a diffuser (25), and a casing (6) connected to the diffuser (25); casing ( 6) is provided with a combustion chamber head (28), and a flame cylinder (5) connected to the combustion chamber head (28), which is characterized in that The fuel injection rod (7) is inserted into the casing (6) and connected to the head of the combustion chamber (28). The head of the combustion chamber (28) is a circular double-ring cavity structure and is divided into duty levels (1) and The main level (2) has two parts; the main level (2) surrounds the outer ring of the duty level (1); The main stage (2) includes a secondary axial cyclone (12), a tertiary axial cyclone (13), a secondary axial cyclone (12) and a tertiary axial cyclone ( 13) between the tongue (14), the premix chamber (15) behind the tongue (14), and the convergent throat (16) behind the premix chamber (15); the convergent throat (16) is in The outlet position of the premix chamber (15); The main stage (2) is also provided with multi-point fuel direct injection holes (22), and the position is opposite to the tongue piece (14). 2. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 1, characterized in that the duty stage (1) includes a primary axial swirler ( 8), the converging section (9), the throat (10), and the expanding section (11) connected in sequence with the first-stage axial cyclone (8). 3. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 1, characterized in that, the flame tube (5) and the casing (6) are arranged between There are combustion inner ring passage (27) and combustion outer ring passage (26). 4. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 1, characterized in that the fuel injection rod (7) is provided with duty-grade centrifugal nozzles (19 ) and the dual oil pipeline of the main-stage oil supply pipe (20); the duty-grade centrifugal nozzle (19) is located at the center of the first-stage axial swirler (8) in the duty-grade (1); the main The stage oil supply pipe (20) is connected with the main stage (2). 5. The main-stage lean-fuel premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 4, characterized in that the main stage (2) sequentially passes through the multi-point fuel direct injection holes (22), the oil collection chamber (21), the main stage oil supply pipe (20) are connected with the oil injection rod (7). 6. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 1, characterized in that the primary axial swirler (8), the secondary axial Axial swirl vanes are installed in the swirler (12) and the three-stage axial swirler (13). 7. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 6, characterized in that the vane installation angle of the secondary axial swirler (12) is The blade installation angle of the first-stage axial swirler (8) is opposite to that of the first-stage axial swirler (8); the blade installation angle of the third-stage axial swirler (13) is the same as that of the second-stage axial swirler (12) Or the other way around. 8. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 1, characterized in that the duty stage (1) and the main stage (2) pass through the head The inner ring cooling assembly (3) is connected; the main stage (2) and the flame tube (5) are connected through the head outer ring cooling assembly (4). 9. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 8, characterized in that the head inner ring cooling assembly (3) is provided with a head Cooling holes (23), the front part of the head inner ring cooling assembly (3) is connected with the head inner ring splash plate (24); the head outer ring cooling assembly (4) is provided with a head There are small holes (17) for cooling the outer ring of the head, and a splash plate (18) for the outer ring of the head is connected to the front of the cooling assembly for the outer head ring (4). 10. The main-stage lean-oil premixed pre-evaporation low-pollution combustion chamber with splash atomization according to claim 8 or 9, characterized in that, the connection means are interconnected by welding or bolts.