CN109059045A

CN109059045A - A kind of poor premixed swirl nozzle of gaseous fuel low pollution combustor and loopful combustion chamber

Info

Publication number: CN109059045A
Application number: CN201810572348.6A
Authority: CN
Inventors: 索建秦; 孙付军; 梁红侠; 于涵; 李乐; 黎明; 石腾
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2018-06-06
Filing date: 2018-06-06
Publication date: 2018-12-21

Abstract

The invention relates to a gas fuel low-pollution combustion chamber lean premixed swirl nozzle and a full-ring combustion chamber, including an axial swirler, a fuel pipeline, a fuel injection hole, a premixing section, an outlet converging section and small divergent holes on the wall surface , a number of fuel injection holes are located on the fuel boss at the end of the fuel pipeline, and the injected fuel is evenly mixed with the swirling air in the premixing section. Low and no local hot spots, thereby effectively reducing the formation of nitrogen oxides; the fuel/air mixture accelerates the flow through the outlet convergence section, reducing the risk of flashback; the small divergent holes on the wall can reduce the wall temperature and the fuel/air ratio of the boundary layer, reducing the occurrence of Risk of spontaneous combustion and flashback; in the actual combustion chamber, by rationally arranging a certain number of swirl nozzles of the same size to form a multi-point lean premixed combustion chamber head, and using the main model fuel staged supply, the combustion chamber can be realized in full working Low pollution emission levels within the environmental range.

Description

A kind of poor premixed swirl nozzle of gaseous fuel low pollution combustor and loopful combustion chamber

Technical field

The invention belongs to gas-turbine combustion chamber fields, are related to a kind of poor premixed swirl spray of gaseous fuel low pollution combustor Mouth and loopful combustion chamber, the poor premixed swirl burner scheme of specifically a kind of low pollution combustor suitable for gaseous fuel.

Background technique

In recent years, with the frequent generation of haze weather in all parts of the country, people gradually recognize ecological environment problem Already become the major issue for influencing human society existence.Since the essential element of traditional energy fuel such as coal and petroleum is Carbon, oxygen, hydrogen, nitrogen and sulphur can generate a large amount of pernicious gas SOx and NOx after burning, can also generate when imperfect combustion a large amount of Unburned particulate matter (PM2.5, the arch-criminal of haze) causes very big pollution to environment, therefore finds clean energy resource quarter and do not allow It is slow.And the essential element of the gases such as natural gas, shale gas is carbon and hydrogen, will not generate sour gas SOx in combustion process, it is not complete Full burning will not generate unburned particulate matter, therefore increasingly have been favored by people, in recent years the gaseous fuels such as natural gas Consumption shows an increasing trend year by year.

However compared with liquid fuel, the gas-turbine combustion chamber of operating on gaseous fuel requires pollutant emission more severe It carves, most of occasions require the pollutant emission of combustion of natural gas room to be NOx < 25ppm, CO < 50ppm, therefore to being used Combustion technology and combustion method more stringent requirements are proposed.Currently, gas turbine combustion with reduced pollutants technology specifically includes that " wet " low emissions combustion technology, catalysis burning minimum discharge technology and " dry " low emissions combustion technology.But due to " wet " low emission The technical bottleneck that combustion technology encounters CO discharge and the negative effect of component life and catalytic combustion technology, therefore " dry " Low emissions combustion technology is still the main direction of development of later gas turbine, and need to sufficiently excavate it reduces the latent of pollutant emission Power." dry " low emissions combustion technology is using premixed combustion mode, and fuel and excess air are sufficiently mixed and enter back into burning later Area's burning, controls combustion zone flame temperature by adjusting the equivalent proportion of fuel-air mixture, so that reaching reduces NOx row The purpose put.

It is domestic that there are many patent applications of the poor premix low pollution combustor about gaseous fuel in recent years.Patent 201711143593.7 disclose a kind of combustion chamber radial multi-stage swirl nozzle for using fuel gas, air flow channel by interior and It is divided into four eddy flow runners outside, and fuel flow channel is divided into main fuel flow channel and secondary grade fuel flow channel, which can fully ensure that Fuel/air mixture is uniformly mixed；Patent 201420733445.6 and patent 201420547162.2 are all made of two-stage eddy flow along axial direction Device strengthens gaseous fuel/air mixing, improves the mixture homogeneity of jet expansion fuel/air mixture.By analyzing it is found that above-mentioned Nozzle radially or axially increased swirl channel, although fuel/air mixture mixing uniformity can be improved, structure slightly dislike it is complicated, Flow resistance is big, and the measure of spontaneous combustion, tempering and hugging occurs without specific prevention.

Summary of the invention

Technical problems to be solved

In order to avoid the shortcomings of the prior art, the present invention proposes a kind of poor pre- mixed of gaseous fuel low pollution combustor Flow nozzle and loopful combustion chamber are a kind of suitable for the poor premixed swirl burner scheme of gaseous fuel low pollution combustor, the program Structure simple possible both can guarantee being sufficiently mixed for fuel/air mixture, moreover it is possible to reduce flow separation, reduce flow resistance loss, adopt simultaneously Measure is taken to reduce the risk that tempering and spontaneous combustion occurs.

Technical solution

A kind of poor premixed swirl nozzle of gaseous fuel low pollution combustor, including cyclone outer wall and axial swirler；Its Be characterized in that: the cyclone inner wall 6 at 4 center of axial swirler is fuel conduit entrance 7, and one end of axial swirler 4 is set There is fuel boss 9, deeply into premix section 10, multiple fuel injection holes 8, fuel spray are uniformly distributed on the inclined-plane of fuel boss 9 The angle in the axle center in the axle center and axial swirler 4 of perforation 8 is β；So that fuel enters from fuel conduit entrance 7, pass through fuel Boss 9 enters premix section 10 via spray-hole 8；Outside the cyclone for premixing section 2 between axial swirler 4 and exit orifice section 11 Wall is equipped with multiple wall surfaces and dissipates aperture 3, is swirl nozzle outlet 12 after exit orifice section 11；The axial swirler 9 Blade is bent blade, is uniformly distributed circumferentially；The internal diameter D of the swirl nozzle outlet 12 is 25mm~40mm, premixes segment length Spending the ratio between S and internal diameter D is 0.7~1.2.

The blade of the low eddy flow axial swirler 9 is 6-20, equal with 8 number of spray-hole.

The blade angle of the bent blade of the low eddy flow axial swirler 9 is 30 °~60 °.

The angle β in the axle center in the axle center and axial swirler 4 of the fuel injection hole 8 is 30 ° -60 °.

The wall surface diverging aperture 3 is evenly distributed along the axial and circumferential directions, is dissipated between the axial spacing of aperture and circumferential direction Away from for 4mm~7mm.

The cyclone outlet converging portion and horizontal direction angle α is 35 ° -55 °.

The combustion zone equivalent proportion of the swirl nozzle is 0.55-0.75.

A kind of loopful combustion chamber constituted using the poor premixed swirl nozzle of the gaseous fuel low pollution combustor, including it is outer Burner inner liner 14, flame cylinder 15 and head flanges 13；It is characterized by: multiple poor premixed swirls of gaseous fuel low pollution combustor Nozzle radially divides three layers from inside to outside and is arranged in head flanges 13, radially three nozzles, one group of main mould and two nozzles One group of secondary mode spacing distribution,.

Described same group of poor premix mould nozzle shares one for cartridge.

The outer layer swirl nozzle is with flame cylinder distance S4 from S1 and internal layer swirl nozzle with outer flame barrel spacing 4mm-8mm, radial distance S2 and S3 are 3mm-5mm between swirl nozzle, and circumferential space D 1 is 10mm-30mm between swirl nozzle.

Beneficial effect

A kind of poor premixed swirl nozzle of gaseous fuel low pollution combustor proposed by the present invention and loopful combustion chamber, including axis Aperture, multiple fuel injection hole locations are dissipated to cyclone, fuel conduit, fuel injection hole, premix section, exit orifice section and wall surface It is uniformly mixed with rotational flow air in premix section in the fuel on the fuel boss of fuel line end, sprayed, swirl nozzle Combustion equivalent ratio is 0.55-0.75, and guarantee combustion zone temperature is lower and without hot localised points, to effectively reduce the life of nitrogen oxides At；Fuel/air mixture accelerates to flow through exit orifice section, reduces tempering risk；Wall surface diverging aperture can reduce wall temperature and Boundary-layer fuel/air rate reduces and spontaneous combustion and tempering risk occurs；In Actual combustion room, pass through reasonable Arrangement certain amount Identical size swirl nozzle formed the poor lean premixed combustor head of multiple spot, and using main mould fuel staging supply, it can be achieved that fire It is horizontal to burn low pollution emission of the room within the scope of full working scope.

Possessed advantage is as follows compared with prior art by the present invention:

Swirl nozzle scheme uses fuel-lean combustion mode, and the equivalent proportion that works is between 0.55-0.75, combustion zone temperature at this time It spends lower, the generation of NOx is effectively reduced；Mode is sprayed and premixed using multiple fuel injection holes, can improve fuel/air mixture mixing The uniformity effectively avoids combustion zone hot spot from occurring, and reduces NOx emission；Cyclone outer wall wall surface diverging aperture can reduce wall temperature and The fuel/air rate of wall surface boundary-layer, so that the risk that spontaneous combustion and tempering occurs be effectively reduced；Due to fuel/air mixture Accelerate outflow swirl nozzle through exit orifice section, so generation tempering risk can be reduced；It is simple and compact for structure, easy to process and dress Match, a certain number of identical swirl nozzles can form the poor lean premixed combustor head of multiple spot by reasonable arrangement mode.

Detailed description of the invention

Fig. 1: the poor premixed swirl nozzle cross-sectional view of the present invention

Fig. 2: the poor premixed swirl nozzle axonometric drawing of the present invention

Fig. 3: the poor premixed swirl nozzle cyclone axonometric drawing of the present invention

Fig. 4: the loopful head of combustion chamber axis of the poor premixed swirl nozzle of gaseous fuel low pollution combustor of the embodiment of the present invention Mapping

Fig. 5: the loopful head of combustion chamber of the poor premixed swirl nozzle of gaseous fuel low pollution combustor of the embodiment of the present invention is left View

In figure: the poor premixed swirl nozzle of 1-, 2- cyclone outer wall, 3- wall surface dissipate aperture, 4- axial swirler, 5- eddy flow Runner, 6- cyclone inner wall, 7- fuel conduit, 8- fuel injection hole, 9- fuel boss, 10- premix section, 11- exit orifice section, The outlet of 12- swirl nozzle, 13- head flanges, the outer burner inner liner of 14-, 15- flame cylinder, 16- pair mould, 17- main mould, 18- multiple spot are poor Lean premixed combustor head Local map, the poor premixed swirl nozzle Local map of 19-.

Specific embodiment

Now in conjunction with embodiment, attached drawing, the invention will be further described:

The invention adopts the following technical scheme: a kind of poor premix suitable for gaseous fuel low-pollution burning chamber of gas turbine Swirl nozzle structure, including cyclone outer wall, wall surface dissipate aperture, axial swirler, eddy flow runner, cyclone inner wall, fuel Pipeline, fuel injection hole, fuel boss, premix section, exit orifice section and swirl nozzle outlet.The eddy flow runner is by axial direction Cyclone, cyclone outer wall and cyclone inner wall surround, and eddy flow flow paths downstream is premix section, the wall surface diverging diverging aperture It is located on the cyclone outer wall at premix section, for reducing wall temperature and boundary-layer fuel/air rate, reduces spontaneous combustion and tempering wind Danger.The fuel conduit is located at cyclone inner wall, and end is fuel boss, and the fuel injection hole equably divides Cloth is on fuel boss.The exit orifice section is located at premix section downstream, for the acceleration outflow of fuel/air mixture mixing, subtracts The small risk being tempered.The swirl nozzle outlet is the minimum flow area of entire swirl nozzle structure, can pass through control Its size is made to adjust the air inflow of swirl nozzle.A certain number of identical swirl nozzles are by reasonably arranging Mode can form the poor lean premixed combustor head of multiple spot, and then apply on Actual combustion room.

The combustion zone equivalent proportion of the swirl nozzle scheme is 0.55-0.75.

The axial swirler blade is bent blade, and the number of blade is 6-20.

The axial swirler blade angle is 30 ° -60 °.

The fuel injection hole count is identical as swirler blades number, is 6-20, fuel injection direction and horizontal direction Angle β be 30 ° -60 °.

The wall surface diverging aperture is evenly distributed in along the axial and circumferential directions on the cyclone outer wall at premix section, axial It is 4mm-7mm with circumferential spacing.

The internal diameter D of the swirl nozzle scheme is 25mm-40mm, and premix the ratio between segment length S and internal diameter D are 0.7-1.2.

Arrangement mode of the swirl nozzle on loopful combustion chamber uses divides three layers of arrangement, each eddy flow from inside to outside Nozzle is all identical, radially triplets or two one group, and two one group is secondary mould, and ternary is main mould, and same group Swirl nozzle share one for cartridge.

Arrangement of the swirl nozzle on loopful combustion chamber, outer layer swirl nozzle and outer flame barrel spacing are from S1 and interior Layer swirl nozzle and flame cylinder distance S4 are 4mm-8mm, and radial distance S2 and S3 are 3mm-5mm, eddy flow spray between swirl nozzle Circumferential space D 1 is 10mm-30mm between mouth.

Specific embodiment:

As shown in Figure 1-3, the embodiment of the invention provides one kind to be suitable for gaseous fuel low-pollution burning chamber of gas turbine Poor premixed swirl nozzle arrangements, including axial swirler 4, cyclone outer wall 2, cyclone inner wall 6, fuel conduit 7, fuel is convex Platform 9, fuel injection hole 8, eddy flow runner 5, premix section 10, exit orifice section 11, wall surface diverging aperture 3 and swirl nozzle outlet 12.The eddy flow runner 5 is surrounded by axial swirler 4, cyclone inner wall 6 and cyclone outer wall 2,4 leaf of axial swirler Piece is bent blade, and the number of blade is 6-20, and blade angle is 30 ° -60 °.The premix section 10 is located at eddy flow runner 5 and outlet is received It holds back between section 11, premix the ratio between segment length L and nozzle diameter D are 0.7-1.2, and nozzle diameter D is 25mm-40mm.The combustion Expects pipe road 7 is located at cyclone inner wall, and end is fuel boss 9, and the fuel injection hole 8 is circumferentially evenly distributed On fuel boss 9, injection hole count is consistent with 4 number of blade of axial swirler, is 6-20, injection direction and horizontal direction Angle β be 30 ° -60 °.Air forms rotational flow through axial swirler 4, and the premix section 10 in downstream is flowed to by eddy channel 5, It meets and mixes with the fuel sprayed through fuel injection hole 8 at premix section 10, then through the acceleration of exit orifice section 11 and from eddy flow Jet expansion 12 flows to swirl nozzle downstream, and it is fuel-lean combustion that swirl nozzle downstream combustion zone equivalent proportion, which is 0.55-0.75,. The exit orifice section 12 and horizontal direction angle α is 35 ° -55 °, for accelerating the rate of outflow of fuel/air mixture, Reduce the risk being tempered.The wall surface diverging aperture 3 is located on cyclone outer wall 2, and portion of air dissipates small through wall surface On the one hand hole 3 reduces cyclone outer wall wall temperature, on the other hand reduces boundary-layer in the 2 adherent flowing in inside of cyclone outer wall Fuel/air rate, to reduce the risk that spontaneous combustion and tempering occurs.

As illustrated in figures 4-5, in practical gas-turbine combustion chamber, the eddy flow of the multiple identical sizes of reasonable Arrangement can be passed through Nozzle 1 forms the poor lean premixed combustor head of multiple spot, and the swirl nozzle 1 can radially divide three layers from inside to outside and be distributed in head On portion's flange 13, outer layer is identical with the swirl nozzle number of middle layer, and internal layer swirl nozzle number is the half of outer layer, wherein edge Radial two swirl nozzles form combustion chamber pair mould 16, and radially three swirl nozzles form combustion chamber main mould 17, all pair moulds 16 all spray fuel work under the small work condition state in combustion chamber, and main mould 17 is to be classified spray fuel with the increase of combustion chamber operating condition Work, main mould are classified work series and are chosen as 6-15 grades according to combustion chamber condition range, and the outer layer swirl nozzle is away from outer flame Distance S1 and the internal layer swirl nozzle of cylinder 14 take 4mm-8mm away from 15 distance S4 of flame cylinder, between the radial direction of adjacent swirl nozzle 3mm-5mm is taken away from S2 and S3, circumferential space D 1 takes 10mm-30mm.

The course of work of the invention is as follows:

Air generates rotational flow through 4 blade of axial swirler, the premix section 10 in downstream is flowed to by eddy channel 5, pre- It meets and mixes with the fuel sprayed through fuel injection hole 8 at mixed section 10, then fuel/air mixture adds through exit orifice section 11 Speed simultaneously flows to downstream from swirl nozzle outlet 12, and swirl nozzle downstream combustion zone equivalent proportion is 0.55-0.75, is fired for poor fuel It burns.Another part gas can flow into swirl nozzle from the wall surface diverging aperture 3 being located on cyclone outer wall 2, in cyclone Inside outer wall forms the cooling air film for being close to wall surface, for reducing wall temperature and boundary-layer fuel/air rate, reduce occur spontaneous combustion and The risk of tempering.

Claims

1. A lean premixed swirl nozzle for a gas fuel low-pollution combustion chamber, comprising a swirler outer wall and an axial swirler; it is characterized in that: the swirler inner wall at the center of the axial swirler (4) ( 6) is the inlet (7) of the fuel pipeline, and one end of the axial swirler (4) is provided with a fuel boss (9), which goes deep into the premixing section (10), and the slope of the fuel boss (9) is uniform A plurality of fuel injection holes (8) are distributed, and the angle between the axis of the fuel injection holes (8) and the axis of the axial swirler (4) is β; so that the fuel enters from the fuel pipeline inlet (7), and passes through The fuel boss (9) enters the premixing section (10) through the injection hole (8); on the outer wall of the swirler of the premixing section (2) between the axial swirler (4) and the outlet converging section (11) There are a plurality of divergent small holes (3) on the wall surface, and the outlet of the swirl nozzle (12) is behind the outlet converging section (11); the blades of the axial swirler (9) are curved blades, which are evenly distributed along the circumferential direction; The inner diameter D of the swirl nozzle outlet (12) is 25 mm to 40 mm, and the ratio of the length S of the premixing section to the inner diameter D is 0.7 to 1.2.

2. The gas fuel low-pollution combustion chamber lean premix swirl nozzle according to claim 1, characterized in that: the low-swirl axial swirler (9) has 6-20 blades, which are connected with the injection holes 8 The numbers are equal.

3. According to claim 1 or 2, the gas fuel low-pollution combustion chamber lean premix swirl nozzle is characterized in that: the blade angle of the curved blade of the low-swirl axial swirler (9) is 30°～ 60°.

4. The gas fuel low-pollution combustion chamber lean premix swirl nozzle according to claim 1, characterized in that: the angle β between the axis of the fuel injection hole (8) and the axis of the axial swirler 4 30°-60°.

5. The gas fuel low-pollution combustion chamber lean premix swirl nozzle according to claim 1, characterized in that: the divergent small holes (3) on the wall are evenly distributed along the axial and circumferential directions, and the axis of the divergent small holes The axial spacing and circumferential spacing are 4mm to 7mm.

6 . The lean premixed swirl nozzle for the gas fuel low-pollution combustion chamber according to claim 1 , wherein the angle α between the convergent section of the swirler outlet and the horizontal direction is 35°-55°.

7. The gas fuel low-pollution combustion chamber lean premix swirl nozzle according to claim 1, characterized in that: the equivalent ratio of the combustion zone of the swirl nozzle is 0.55-0.75.

8. A full-ring combustor utilizing any gas fuel low-pollution combustor lean premixed swirl nozzle according to claims 1 to 7, comprising an outer flame tube (14), an inner flame tube (15) and a head The head flange (13); it is characterized in that: a plurality of gas fuel low-pollution combustion chamber lean premixed swirl nozzles are arranged on the head flange (13) in three layers along the radial direction from inside to outside, and along the diameter The main mold with one set of three nozzles and the secondary mold with one set of two nozzles are distributed at intervals.

9. The full-ring combustor according to claim 6, characterized in that: the same group of lean premixed nozzles share one fuel supply pipe.

10. The full-circle combustion chamber according to claim 6, characterized in that: the distance S1 between the outer swirl nozzle and the outer flame tube and the distance S4 between the inner swirl nozzle and the inner flame tube are 4mm-8mm, and the swirl flow The radial distances S2 and S3 between the nozzles are 3mm-5mm, and the circumferential distance D1 between the swirl nozzles is 10mm-30mm.