Fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber
Technical field:
The present invention relates to a kind of fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber, refer in particular to and be a kind ofly applied to the fuel-rich combustion/quench/poor oil firing of civil aviation gas-turbine unit and lean premixed preevaporated combination low emission standing vortex burning chamber, belong to gas turbine low emissions combustion technical field.
Background technology:
Along with the pay attention to day by day to environmental protection, countries in the world and relevant international organization have formulated the environmental regulation of increasingly stringent, have made clear and definite specification and regulation to the discharge standard of various power set.Such as aviation power, Jin30Nian Lai International Civil Aviation Organization (International Civil Aviation Organization, ICAO) has formulated multiple discharge standard regulations such as CAEP1 (1986), CAEP2 (1996), CAEP4 (2004), CAEP6 (2008) and CAEP8 (2010) successively.From the total amount that global Air-pollution From Combustion is discharged, although the share shared by the discharge of engine is very little, but it has locality and altitude features of pollution, therefore need to develop the engine chamber with low emission performance, to reduce environment and healthy impact.Development and raising under the promotion of low emission combustor and combustion technology this research background just.For adapting to constantly strict environmental protection standard specification, ensure the following occupation rate to market, European and American countries has all dropped into the research that a large amount of manpower financial capacity carries out low emissions combustion technology, and has obtained obvious effect.Energy-saving efficient engine (E3) as U.S.'s the seventies in last century is planned, high speed research aircraft (HSR) plan of clean environment combustion chamber project (ECCP), the nineties, advanced subsonic speed technology (AST) are planned and the ultra high efficiency engine technology (UEET) of initiation in 1999 is planned, and Europe has been worked out EFFAE plan, VITAL plan and GEAE and SNECMA and combined the TECH56 (1998 ~ 2003) of initiation and LEAP56 subsequently plan etc. since 2000.
Fuel-rich combustion/quench/poor oil firing (Rich/Quench/Lean, RQL) technology first whole fuel oil and partial air is carried out fuel-rich combustion, reduce the NOx in fuel-rich combustion district by reducing ignition temperature, then Fuel-rich gas quick mixing with two strands of air carries out poor oil firing.Owing to having a large amount of burnt gas in district of poor oil firing, ignition temperature is low, thus reduces NOx generation.A key technical problem is had: how Fuel-rich gas carries out mixing fully fast with fresh air in RQL technology.Fuel-rich combustion/quench/poor oil firing (RQL) technology is that PW company and NASA progressively develop perfect by AST, UEET project, and its application represents TALON combustion chamber and developed into for the 4th generation.1st generation TALON comes into operation combustion chamber on PW4098, meets CAEP2 emission request, but does not reach CAEP4 emission request.2nd generation TALON combustion chamber adopts the measures such as pneumatic nozzle, newly-designed cooling air hole, floating wall burner inner liner, decrease cooling air volume, (comparatively CAPE2 reduces by 40% ~ 50% to reduce NOx emission value, and UHC, CO and cigarette discharge value do not increase), PW 4156, PW4168, PW6000, PW8000 apply.3rd generation TALON combustion chamber (MSQ combustion chamber) have employed monoblock cast diffuser, pneumatic nozzle, band SiC/SiC ceramic matric composite coating and impacts the floating wall burner inner liner of air film cooling technology, its NOx, CO, UHC discharge value meets CAEP6 requirement, and has larger nargin.A new generation TALON X combustion chamber is studied under the UEET plan of NASA, and it mainly improves and comprises low fuel nozzle of being fuming, low cooling gas flame cylinder, air admission hole optimisation technique and residence time control etc., to reach low emission, long-life target.
Lean premixed preevaporated (Lean Premixed Prevaporized, LPP) combustion technology is that fuel oil is evaporated in advance, mixes in advance with air, in main chamber, then forms even oil-poor mixed gas burn.Local temperature and oil-gas ratio are depended in being formed in of NOx to a great extent.For equivalent proportion close to 1 mixed gas, the formation of NOx presents a maximal peak, and poor oil firing can reduce ignition temperature, realizes premix and pre-evaporation in upstream, combustion chamber, can reduce district of localized hyperthermia, shortens residence time, thus suppresses the generation of NOx.The advantage of LPP combustion chamber is the air capacity minimizing of not carbon deposit, cooling flame cylinder.Its shortcoming may cause issuing in high inlet temperature being conigenous combustion or tempering at the premixed prevapourising of upstream, combustion chamber.
In the development course of combustion chamber, update by swirl stabilized obtaining of traditional combustion room, these improvement decrease pollutant emission, but still face bottleneck and challenge, the more and more difficult requirement meeting increasingly strict discharge standard.Meanwhile, various new concept combustion system and combustion technology flourish, trapped vortex combustion technology just belongs to one of them.The U.S. is the country proposing standing vortex burning chamber (Trapped-vortex Combustor, TVC) concept the earliest, its to the research of TVC technology the earliest, achievement is also maximum.Last century the nineties, the people such as U.S. Hsu have devised first generation TVC model, developed again afterwards the second generation, the third generation and band high-pressure installation third generation TVC.TVC technology is through the development of more than ten years, and its principle also becomes clear, and performance is also progressively found by excavation.Foreign study finds that standing vortex burning chamber can obtain extraordinary performance in real-world conditions: compared with routine techniques, improve 50% at ignition performance, fuel-lean blowout performance, high-altitude ignition aspect of performance; Nitrogen oxide emission reduces 40% ~ 60% than ICAO standard C AEP2 in 1996; The working range that efficiency of combustion meets or exceeds 99% widens more than 40%.
Because the oil-gas ratio scope of aero gas turbine engine between idling rating to maximum rating is very large, only utilize RQL technology or only utilize LPP technology to be all difficult to the target realizing reducing discharge within the scope of full working scope.
Therefore, necessary the deficiency solving prior art is improved to prior art.
Summary of the invention:
The invention provides a kind of fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber, it can realize the target reducing discharge within the scope of aero gas turbine engine full working scope.
The present invention adopts following technical scheme: a kind of fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber, and it comprises:
Diffuser, air enters in described combustion chamber from described diffuser;
Casing, described casing includes outer casing and interior casing;
Part flow arrangement, described air is divided into inside and outside culvert air-flow and main flow air-flow from described part flow arrangement;
Cavity, described cavity includes inner ring cavity and outer shroud cavity, described cavity is provided with cavity antetheca air inlet and cavity rear wall air inlet;
Burner inner liner, described burner inner liner is provided with some flame tube wall Cooling Holes;
Described fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber also include for prevapourising fuel oil and the main flow prevapourising device stabilized the flame and the connection flame device for transmitting flame, described fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber also comprise promising described inner ring cavity and outer shroud cavity provides the main combustion stage fuel manifold of fuel and level fuel manifold on duty, described fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber adopt fuel-rich combustion/quench/poor oil firing's technology under slow train and state of marching into the arena, taking off, climb, lean premixed preevaporated technology is adopted under cruising condition, in described fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber under fuel-rich combustion/quench/poor oil firing's mode of operation, main combustion stage fuel manifold not fuel feeding, described level fuel manifold fuel feeding on duty, the main whirlpool of cavity and the secondary whirlpool of cavity is formed in described main flow air-flow flow area, the main whirlpool of described cavity is fuel-rich combustion level, the secondary downstream part, whirlpool of described cavity is extinguishing level, described cavity secondary whirlpool upstream portion is poor oil firing's level, in cross section, described flame device place, the main whirlpool of cavity is fuel-rich combustion level, space between cavity and connection flame device is extinguishing level, described flame device and described main flow prevapourising device tail are poor oil firing's level.
Described fuel-rich combustion level equivalent proportion is between 1.3-1.6, and poor oil firing's level equivalent proportion is between 0.5-0.8.
In described fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber under lean premixed preevaporated mode of operation, the level fuel nozzle on duty be arranged on described level fuel manifold on duty adopts swirl atomizer, described swirl atomizer is installed on described cavity antetheca air inlet, enter cavity together with air, participate in burning.
The fuel system of described main combustion stage fuel manifold is simple nozzle.
Described level equivalent proportion on duty is 0.8, and described main combustion stage equivalent proportion is between 0.5-0.6.
Described combustion chamber is toroidal combustion chamber.
Described burner inner liner wall adopts effusion wall mode, impinging cooling or impacts air film mode and cools.
The present invention has following beneficial effect:
(1) under idling rating and state of marching into the arena, adopt fuel-rich combustion/quench/poor oil firing (RQL) technology, under small-power state, effectively reduce discharge, and improve stability;
(2) taking off, climb, adopt lean premixed preevaporated (LPP) technology under cruising condition, under high-power state, reduce pollutant emission.
Accompanying drawing illustrates:
Fig. 1 is that fuel-rich combustion of the present invention/quench/poor oil firing (RQL) combines low emission standing vortex burning chamber structural representation with lean premixed preevaporated (LPP).
Fig. 2 is the partial sectional view of fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber.
Fig. 3 is the burner inner liner partial sectional view in fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber.
Fig. 4 is the main flow prevapourising apparatus structure schematic diagram in fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber.
Fig. 5 is the main flow prevapourising device operation principle schematic diagram shown in Fig. 4.
Fig. 6 is the fuel manifold schematic diagram in fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber.
Fig. 7 is main flow flow area combustion process schematic diagram under fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber fuel-rich combustion/quench/poor oil firing (RQL) mode of operation.
Fig. 8 is fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber fuel-rich combustion/cross section, quench/poor oil firing (RQL) mode of operation second line of a couplet flame device place combustion process schematic diagram.
Fig. 9 is main flow flow area combustion process schematic diagram under fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber lean premixed preevaporated (LPP) mode of operation.
Figure 10 is fuel-rich combustion/quench/poor oil firing of the present invention and cross section, lean premixed preevaporated combination low emission standing vortex burning chamber lean premixed preevaporated (LPP) mode of operation second line of a couplet flame device place combustion process schematic diagram.
Wherein:
1-standing vortex burning chamber, the outer casing of 2-, casing in 3-, 4-diffuser, 5-high-energy spark plug, the import of 6-main combustion stage fuel manifold, the import of 7-level fuel manifold on duty, 8-main combustion stage fuel manifold, 9-level fuel manifold on duty, 10-part flow arrangement, 11-burner inner liner, 12-flame tube wall Cooling Holes, the import of 13-cavity antetheca cold gas, 14-main flow prevapourising device, plate is spattered in 15-reflection, 16-evaporation cavity, 17-evaporation cavity exports, 18-V shape groove, 19-cavity antetheca air inlet, 20-cavity rear wall air inlet, 21-outer shroud cavity, 22-inner ring cavity, 23-joins flame device, 24-main combustion stage oil outlet, 25-level fuel nozzle on duty, the main whirlpool of 26-cavity, the secondary whirlpool of 27-cavity, 28-extinguishing district, district of 29-poor oil firing, 30-primary zone.
Detailed description of the invention:
Please refer to shown in Fig. 1 to Fig. 6, fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber 1 are primarily of compositions such as outer casing 2, interior casing 3, diffuser 4, main combustion stage fuel manifold 8, level fuel manifold 9 on duty, part flow arrangement 10, burner inner liner 11, main flow prevapourising devices 14.Air enters combustion chamber from diffuser 4 import, to slow down supercharging through diffuser 4, is beneficial to the tissue burnt.Burner inner liner 11 wall needs to distributed a large amount of flame tube wall Cooling Holes 12 according to cooling; The effect that main flow prevapourising device 14 transmits flame with connection flame device 23 shared and stabilizes the flame; Main combustion stage fuel manifold 8 provides fuel for outer shroud cavity 21 and inner ring cavity 22; Under the effect of part flow arrangement 10, air enters provided with internal duct and external duct and main flow respectively; Inside and outside air-flow of containing enters cavity from cavity antetheca air inlet 19 and cavity rear wall air inlet 20 respectively, and remaining air enters burner inner liner 11 from flame tube wall Cooling Holes 12 respectively; Primary air enters burner inner liner 11 from the gap between connection flame device 23.
Combustion chamber in the present invention is toroidal combustion chamber, and whole Combustion chamber design is 22 heads.
Fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber 1 Flame cylinder 11 wall adopt effusion wall mode to cool.In other embodiments, other more advanced types of cooling can be used, meet the different needs, such as impinging cooling, impact air film.
Under LPP mode of operation, main combustion stage fuel oil sprays into prevapourising device 14 by the main combustion stage oil outlet 24 on main combustion stage fuel manifold 8 is reverse, then under the rebound effect of plate 15 is spattered in reflection, enters evaporation cavity 16, or beats on V-shaped groove 18 wall.The high-temperature fuel gas from cavity in tail due to prevapourising device 14, so under V-shaped groove 18 wall and evaporation cavity 16 be in higher temperature, be conducive to the abundant evaporation of oil droplet.A small amount of air enters evaporation cavity 16 from penetrating the gap spattered between plate 15 and prevapourising device wall, and sprays into primary air with oil vapour from evaporation cavity outlet 17, mixes, form lean premixed gas, enter primary zone in upstream, primary zone.
The oil supply system of fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber 1 is divided into main combustion stage fuel manifold 8 and level fuel manifold 9 on duty.Under RQL mode of operation, main combustion stage is fuel feeding not, only level fuel feeding on duty.Under LPP mode of operation, level fuel nozzle 25 on duty adopts swirl atomizer, is arranged on cavity antetheca air inlet 19, enters cavity together with air, participates in burning; It is simple nozzle that main combustion stage fuel oil feeds mode.
Please refer to Fig. 1 to Fig. 6 and shown in composition graphs 7 to Fig. 8, fuel-rich combustion/quench/poor oil firing of the present invention and the mode of operation of lean premixed preevaporated combination low emission standing vortex burning chamber at slow train and when marching into the arena: RQL mode of operation.Fuel oil all feeds in inner and outer ring cavity 21,22, and be fuel-rich combustion in cavity, equivalent proportion is 1.3-1.6.Under idling rating, although its amount of fuel and temperature rise are not high, in the LTO circulation that International Civil Aviation Organization defines, the working time of idling rating is the longest, and its discharge capacity is also appreciable, so take RQL mode of operation in this condition; And when marching into the arena, thrust reaches 30%, combustor inlet temperature is now than the combustor inlet temperature height 200-250K under idling rating, fuel delivery is now 3-4 times of fuel delivery under idling rating, discharge higher, but not high-power, without the need to being designed to LPP mode of operation (amount of fuel is inadequate), therefore being designed to RQL mode of operation under this marches into the arena state.
The course of work of RQL pattern of the present invention: at slow train with when marching into the arena, feeds all fuel oils in cavity.As shown in Figure 7 and Figure 8, all fuel oils enter in the main whirlpool 26 of cavity with cavity antetheca air inlet 19 air-flow, and equivalent proportion is controlling between 1.3-1.6, form fuel-rich combustion district.The main whirlpool 26 of cavity as shown in Figure 7 and cavity secondary whirlpool 27 structure will be formed at main flow flow area.In the downstream part in the secondary whirlpool 27 of cavity, have two parts fresh air to mix with burnt gas, diluted, a part is from cavity rear wall air inlet 20, and another part is from main flow.Therefore, in the downstream part in the secondary whirlpool 27 of cavity, equivalent proportion declines to a great extent, and forms extinguishing district 28.In the upstream portion in the secondary whirlpool 27 of cavity, there is mixed gas the supplementing due to fresh air of extinguishing, restart burning, form district of poor oil firing 29.The gaseous mixture completely that burns enters main flow, and enters turbine by combustor exit together with main flow.In the cross section at connection flame device 23 place, single vortex structure as shown in Figure 8 will be formed.The product in fuel-rich combustion district forms extinguishing district 28 under the blending effect of cavity rear wall air inlet 20 air-flow, and extinguishing district 28 air-flow flows in connection flame device 23 tail under differential pressure action, and burns away, and forms district of poor oil firing 29.As mentioned above, whole combustion process will be controlled in 1600k-1900k, effectively can reduce nitrogen oxide (NOx) discharge.
Please refer to Fig. 1 to Fig. 6 and shown in composition graphs 9 to Figure 10, fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber taking off, climb, mode of operation when cruising: LPP mode of operation.A small amount of fuel oil feeds in inner and outer ring cavity 21,22, and serve as level on duty, equivalent proportion, about 0.8, takes into account high efficiency and low emission; Another part fuel oil enters main flow prevapourising device 14 from main combustion stage fuel manifold 8, serves as main combustion stage.Fuel oil carry out in evaporation cavity 16 prevapourising laggard enter main flow, forming equivalent proportion is lean premixed gas namely close to lean extinction limit between 0.5-0.6, then enters primary zone 28 and carries out poor oil firing, significantly reduces gaseous contaminant discharge.
The course of work of LPP pattern of the present invention: taking off, climb, when cruising, standing vortex burning chamber is divided into level on duty and main combustion stage, and main combustion stage realizes LPP pattern.Partial air and fuel enter cavity, and in the control main whirlpool 26 of cavity, equivalent proportion is about 0.8, and fuel carries out the burning of stability and high efficiency in the main whirlpool 26 of cavity, as the level on duty of whole combustion chamber.After main flow fuel oil carries out prevapourising in prevapourising device 14, spray into main flow from evaporation cavity 16 outlet, carry out premix with main flow, thus form equivalent proportion and mix gas close to the premix and pre-evaporation of lean extinction limit, then enter primary zone 30 to burn, as the main combustion stage of whole combustion chamber.As shown in Figure 9, at main flow flow area, in cavity, yet forms both the secondary whirlpool 27 of cavity except the main whirlpool 26 of cavity.Secondary being formed of whirlpool 27 of cavity helps high speed main flow and the main whirlpool 26 of cavity to separate, and is conducive to main vortex stability, and relies on the secondary whirlpool 27 of cavity main flow reliably to be lighted with the mass exchange in main flow and cavity main whirlpool 26.As shown in Figure 10, in connection cross section, flame device 23 place, single vortex structure is only defined in cavity, but, the mixed gas that fires in the main whirlpool of cavity 26 flows in the tail of connection flame device 23 and main flow pre-mixing apparatus 14 under differential pressure action, add the contact area of firing mixed gas and the oil-poor flammable mixed gas of main flow, contribute to lighting main flow more reliably, and raise the efficiency.In LPP mode of operation, level equivalent proportion on duty is in comparatively high equivalent weight ratio (about 0.8), but level fuel oil proportion on duty is very little, and most of fuel oil is in the very low main flow of equivalent proportion, therefore whole combustion chamber NOx discharge is very low.
The igniting of fuel-rich combustion/quench/poor oil firing of the present invention and lean premixed preevaporated combination low emission standing vortex burning chamber and flame stabilization: when cavity size and front and rear wall air inlet 19,20 Proper Match, stay formation in cavity and determine vortex system.Fuel oil sprays from level fuel nozzle 25 on duty, enters in cavity together with cavity antetheca air inlet 19 air, enters in the main whirlpool 26 of cavity under the effect of vortex with air, and along with the evaporation of fuel oil, forms flammable mixed gas.In a certain particular moment, ignition system is connected, and high-energy spark plug 5 two electrode voltages exceed air breakdown threshold values, send electric spark, form the high-temperature plasma district of a similar diffusion flame shape, light the combustion mixture near sparking plug, form the core fire group with sufficient size and temperature.This core fire group, while surrounding propagating flame, moves with air-flow, and under this double effect, flame propagation, in the recirculating zone in the main whirlpool 26 of cavity, forms point of safes burning things which may cause a fire disaster; After incoming mixture enters cavity, carry out heating and being lighted under the effect of this point of safes burning things which may cause a fire disaster; The circumference of flame is propagated, and will light adjacent head, and will be lighted by whole outer shroud cavity 21 further, so just indicate and light a fire successfully.In connection cross section, flame device 23 place, the gaseous mixture part entering cavity from antetheca enters in recirculating zone, cavity main whirlpool 26, and another part flows in the following wake of connection flame device 23 under the driving of differential pressure action.In the following wake of connection flame device 23, inner ring cavity 22 unburned mixture and outer shroud cavity 21 have fired high-temperature gas mixture and have contacted, and are lighted, and then flame propagation is in inner ring cavity 22, and final whole level on duty is lighted and smooth combustion.
This fuel-rich combustion/quench/poor oil firing and lean premixed preevaporated combination low emission standing vortex burning chamber adopt fuel-rich combustion/quench/poor oil firing (RQL) technology under idling rating and state of marching into the arena, under small-power state, effectively reduce discharge, and improve stability; Taking off, climb, adopt lean premixed preevaporated (LPP) technology under cruising condition, under high-power state, reduce pollutant emission.
Another embodiment of the invention is, slow train and only cavity fuel feeding of marching into the arena under state, adopt fuel-rich combustion/quench/poor oil firing (RQL) technology; And taking off, climb, cruising condition time cavity and main flow fuel feeding simultaneously, fuel-rich combustion/quench/poor oil firing (RQL) is adopted in cavity, main flow adopts lean premixed preevaporated (LPP) burning, meets the requirement of high efficiency and low emission simultaneously.
The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, can also make some improvement under the premise without departing from the principles of the invention, and these improvement also should be considered as protection scope of the present invention.