The fuel oil injection of a kind of combustion chamber and mixing arrangement and combustion chamber thereof
The invention belongs to energy and power engineering burner field, particularly a kind of combustion chamber fuel oil injection and mixing arrangement and combustion chamber thereof of aero-engine.
Along with atmospheric environment problem worldwide receives increasing concern, for aero-engine pollutant emission, require more and more stricter especially.The Aeroengine Products market demand of future generation shows, the discharge capacity of nitrogen oxide (NOx) also will reduce by 50% left and right than existing International Civil Aviation Organization (ICAO) required standard, and the discharge index that simultaneously other emission is all stipulated than ICAO such as carbon monoxide (CO) and unburned carbon hydrogen (UHC) retains certain nargin.
Research shows, the maximum gas temperature that control combustion is indoor and combustion zone temperature uniformity are the keys of controlling NOx disposal of pollutants, and one of Major Technology of control combustion district temperature is exactly to adopt lean premixed combustion mode.But under the duties such as ground idle speed, starting ignition, need again combustion zone to adopt the diffusion combustion fuel-air matching mode that approaches stoichiometric ratio, to guarantee combustibility, also can reduce CO and UHC discharge under small-power state simultaneously.In order to solve the contradiction of CO, UHC discharge under the discharge of NOx under high-power state and small-power state, can adopt the pattern of fractional combustion, under assurance engine different capacity, combustion chamber regional area burns with best fuel-air match pattern.The grading combustion technology application of having succeeded on aeroengine combustor buring chamber, more work is being done by GE company aspect the low emission combustor of this type, designed can realize poor oil firing fuel injection equipment (FIE) for the application of engine engineering, such as the dicyclo cavity combustion chamber grading combustion technology that some engine adopts; The center grading combustion technology that some engine adopts etc.
Because compact conformation, subregion poor oil firing are controlled the advantages such as NOx effect is better, adopting center grading combustion technology has been the trend of low emission combustor development.But existing grading combustion technology, not can solve between subregion interact, near the low inferior problem of efficiency of combustion classification point.And three grades interact at fuel oil jet segment for oil firing, oil gas allotment will meet combustion requirements and the emission request of each combustion zone simultaneously and realize comparatively difficulty.
Summary of the invention
The technical problem to be solved in the present invention is to reduce the discharge capacity of CO and UHC under 30% thrust rating of ICAO regulation, solves the 30% thrust rating efficiency of combustion problem on the low side occurring in fractional combustion, can not weaken the NOx discharge under high-power state simultaneously.
According to a first aspect of the invention, provide a kind of combustion chamber fuel oil to spray and mixing arrangement, it is characterized in that, described device comprises pre-combustion grade, intergrade and main combustion stage, and described intergrade is around described pre-combustion grade, and described main combustion stage is around described intergrade, wherein:
Described pre-combustion grade comprises swirl atomizer, around the one-level cyclone of described swirl atomizer, around the Venturi tube of described one-level cyclone and around the second cyclone of described Venturi tube;
Fuel feeding path in the middle of described intergrade comprises, lining, around the intergrade cyclone of described lining and around the sleeve of described intergrade cyclone, described in the middle of fuel feeding path supply fuel to the space of described intergrade cyclone downstream between described sleeve and described lining;
Described main combustion stage comprises main fuel feeding path, main combustion stage inwall, around the main combustion stage cyclone of described main combustion stage inwall and around the main combustion stage outer wall of described main combustion stage cyclone, described main fuel feeding path supplies fuel to the space of described main combustion stage cyclone downstream between described main combustion stage inwall and main combustion stage outer wall; And
The end of described main combustion stage inwall is connected with the end of described sleeve and forms a cavity, the end of described main combustion stage inwall is provided with at least one Cooling Holes, upstream air enters described cavity and by described Cooling Holes, impacts the end of described sleeve, thus the end of cooling described main combustion stage inwall and the end of described sleeve.
Wherein, described main fuel feeding path and/or middle fuel feeding path are provided with nozzle.
Wherein, described nozzle adopts pressure atomization structure or pneumatic nebulization structure.
Wherein, described nozzle comprises at least one spray site or adopts domain liquid film to spray.
Wherein, described pre-combustion grade, described intergrade and described main combustion stage inwall form an integral body by welding and/or monoblock cast, and coordinate with described main combustion stage cyclone axial float.
According to a second aspect of the invention, provide a kind of combustion chamber, comprise that aforesaid combustion chamber fuel oil sprays and mixing arrangement.
Beneficial effect of the present invention:
1. simple and compact for structure, adopted level Four cyclone, three combustion zone independent oil supplies, fuel-air matching is very convenient, and fuel oil regulates freely.
2. according to the demand ，Cong center of the engine different capacity 3 grades of independent partitions fuel feeding such as pre-combustion grade, intergrade, main combustion stage of radially having arranged.Wherein, main combustion stage and intergrade adopt respectively direct-injection type multi-point fuel injection or domain liquid film injection design, and fuel oil sprays in the swirling eddy of cyclone generation, and atomizing effect is good.
3. between three grades of fuel feeding, interact less, avoid near the classification status point of combustion chamber producing the local air-fuel mixture district that is unfavorable for burning, can in compared with wide operating range, solve well the contradiction of the classification status point NOx discharge that faces in grading combustion technology and CO, UHC discharge performance.
Accompanying drawing explanation
Below in conjunction with accompanying drawing, describe in detail according to a preferred embodiment of the invention, wherein:
Fig. 1 shows the cutaway view with the preferred embodiment of mixing arrangement according to the injection of combustion chamber of the present invention fuel oil;
Fig. 2 shows combustion chamber fuel oil in Fig. 1 and sprays the assembling schematic diagram with mixing arrangement.
Description of reference numerals
1 mating surface 2 mating surfaces
3 main combustion stage cyclone 4 walls
The main fuel feeding path of 5 wall 6
Fuel feeding path in the middle of 7 nozzles 8
9 intergrade cyclone 10 nozzles
11 sleeve 12 swirl atomizers
13 Venturi tube 14 one-level cyclones
15 second cyclone 16 spray orifices
17 lining 18 main combustion stage outer walls
19 main combustion stage inwall 20 Cooling Holes
21 end 22 main combustion stage passages
The specific embodiment
Some terms of paper the art, wherein:
Cyclone: make γ-ray emission tangential velocity be rotated mobile device;
Venturi tube: accelerate the annular tubular structure that air-flow prevents tempering, fuel oil liquid mist is beaten and form liquid film assisted atomization on Venturi tube wall;
Fractional combustion: refer to fuel oil, the mixed combustion of air subregion, burn in zones of different;
Nozzle: the device of fuel-oil atmozation;
Fuel-oil atmozation: utilize nozzle liquid fuel to be become to oil droplet group's process;
Stoichiometric ratio: fuel oil and air are according to the pro rate of completing combustion;
Oil-poor: fuel ratio is less than stoichiometric ratio mixed proportion, i.e. air excess, fuel oil is on the low side;
Premixed combustion: fuel oil and air carried out mixed uniformly combustion system before burning;
Diffusion combustion: fuel oil sprays into the combustion zone mixing of atomization on one side and contacts and carry out the combustion system of chemical reaction on one side with air.
Shown in Fig. 1 and Fig. 2, according to combustion chamber of the present invention fuel oil, spray with mixing arrangement and adopt fuel oil injection, the air-fuel mixture system being formed by fuel nozzle system and cyclone, and be provided with 3 grades of independent partitions fuel feeding according to arranging of center classification.Whole device is connected with splash pan with the group section of combustion chamber flame drum head end wall with mating surface 2 by mating surface 1 is installed.
Fig. 1 shows whole device along the cutaway view of central axis.Combustion chamber fuel oil sprays with mixing arrangement and comprises pre-combustion grade, intergrade and main combustion stage, and intergrade is around pre-combustion grade, and main combustion stage is around intergrade.
Pre-combustion grade adopts eddy flow cup structure air atomizer spray nozzle, comprises swirl atomizer 12, around the one-level cyclone 14 of swirl atomizer 12, around the Venturi tube 13 of one-level cyclone 14 and around the second cyclone 15 of Venturi tube 13.Fuel oil forms spray cones from spray orifice 16 ejection of swirl atomizer 12 and beats on Venturi tube 13 walls, and atomization spray into combustion chamber under the swirling eddy shear action of the one-level cyclone 14 of inner side and the second cyclone 15 in outside.
Fuel feeding path 8 in the middle of intergrade comprises, lining 17, around the intergrade cyclone 9 of lining 17 and around the sleeve 11 of intergrade cyclone 9, middle fuel feeding path 8 is connected with fuel system, supplies fuel to the space of intergrade cyclone 9 downstreams between sleeve 11 and lining 17.Fuel oil sprays in the passage forming between the wall of lining 17 and sleeve 11 from nozzle 10, and under the swirling eddy effect that goes out interruption-forming of intergrade cyclone 9, atomization sprays into combustion chamber.Fuel system adopts multi-point injection or the employing domain liquid film that circumferential Central Symmetry is arranged to spray.
Main combustion stage comprises main fuel feeding path 6, main combustion stage inwall 19, around the main combustion stage cyclone 3 of main combustion stage inwall 19 and around the main combustion stage outer wall 18 of main combustion stage cyclone 3, between main combustion stage inwall 19 and main combustion stage outer wall 18, form main combustion stage passage 22, main fuel feeding path 6 is connected with fuel system, supplies fuel in the main combustion stage passage 22 in main combustion stage cyclone 3 downstreams.Fuel oil spray to adopt the multi-point injection that circumferential Central Symmetry arranges or the nozzle 7 that adopts domain liquid film to spray, and the fuel oil spraying into goes out atomization under the swirling eddy effect of interruption-forming and sprays into combustion chamber at main combustion stage cyclone 3.
The end 20 of main combustion stage inwall 19 is connected with the end 21 of sleeve 11 and forms a cavity, the end 20 of main combustion stage inwall 19 is provided with at least one Cooling Holes 20, upstream air enters cavity and by Cooling Holes 20, carrys out the end 21 of impingement sleeve 11, the end 20 of cooling main combustion stage inwall 19 and the end 21 of sleeve 11 thus, that is, the group section between cooling main combustion stage and intergrade.
In certain embodiments, nozzle 7 or 10 can adopt pressure atomization structure or pneumatic nebulization structure, and comprises at least one spray site or adopt domain liquid film to spray.
As shown in Figure 2, the cyclones at different levels of the pre-combustion grade of fuel injection equipment (FIE), intergrade, main combustion stage are connected group section and main combustion stage inwall and are designed to adopt welding and/or monoblock cast to form an integral body with assembly.This assembly integral body can move and carry out dismounting along centerline direction, coordinates with main combustion stage cyclone axial float, and assemblage gap mating surface is between wall 5 and the wall 4 of outermost main combustion stage cyclone 3.In figure dashed region be can dismounting assembly whole, during assembling by the slope outer wall of wall 5 along the center line importing that endwisely slips from left to right.
The present invention is according to the demand of engine different capacity, the center radial direction 3 grades of independent partitions fuel feeding such as pre-combustion grade, intergrade, main combustion stage of having arranged.Between 3 grades of fuel feeding, interact less, avoid near the classification status point of combustion chamber producing the local air-fuel mixture district that is unfavorable for burning, can in compared with wide operating range, well solve the contradiction of the classification status point NOx discharge that faces in grading combustion technology and CO, UHC discharge performance.
Described in the present invention, concrete case study on implementation is only better case study on implementation of the present invention, is not used for limiting practical range of the present invention.Be that all equivalences of doing according to the content of the present patent application the scope of the claims change and modify, all belong to protection scope of the present invention.