Background technology
Along with energy scarcity and the whole world are to the attention of environmental protection problem; the requirement of various countries to gas-turbine combustion chamber discharge and efficiency of combustion is more and more stricter; General Requirements gas turbine is between 50% and above loading zone; combustion chamber discharge can maintain reduced levels, keeps higher efficiency of combustion simultaneously.In order to reach the object of low emission, premixed combustion technology is widely adopted.Therefore, nozzle needs to realize being pre-mixed of fuel and air, and forms the fuel-air mixture mixing and have certain speed type at nozzle exit, and then enters in burner inner liner and participate in burning.
Because the mode of fuel with premixed flame in combustion chamber ejected from nozzle is burnt, for reaching extremely low disposal of pollutants, flame is operated near flammable border, add the fuel-air mixture body effluxvelocity that top nozzle ejects larger, the stable of premixed flame is more difficult, in prior art solution normally centerbody axial length be less than the length in outer nozzle wall face, fuel-air mixture is first expanded to the central area in centerbody head end wall downstream when annular premixed channel flows out, in the formation recirculating zone, central area in centerbody head end wall downstream, then expansion further in the inherent burner inner liner of burner inner liner is entered, and then in burner inner liner, form larger recirculation zone, stablizing for premixed flame, but these two recirculation zone are subject to the influence of other air-flows in burner inner liner, this method be simple from formed stablize recirculating zone air angle to improve the stability of premixed flame, under the duty parameter of larger load, due to inlet pressure, inlet temperature and fuel-air mixture equivalent proportion higher, nozzle still can be easy to realize reliable flame stabilization and higher efficiency of combustion, and compared with under the duty parameter of underload, due to inlet pressure, inlet temperature and fuel-air mixture equivalent proportion lower, be unfavorable for the stable of premixed flame, efficient burning, premixed flame is existed can not stablize or poor stability and the low risk of efficiency of combustion.
In order to improve the stability of flame, in existing patent document (CN1704574), have employed the manufacture shock air contrary with main flow flow direction near jet expansion centerbody to flow, form recirculation eddy current, decrease the air capacity be ejected in recirculating zone, thus effluxvelocity near reduction jet expansion, improve flame holding.This method just improves the stability in local return district from pneumatic angle, only can there is certain effect to the stable of premixed flame, and due to the essence of premixed combustion, this method reliably can not improve the steady fire performance of nozzle, more can not ensure that premixed flame is compared with having higher efficiency of combustion under underload; In addition, from processing technology angle, the structure processing connections such as this premixing nozzle internal layer baffle plate wait comparatively complicated, and are not easy to maintain and replace.
Therefore, for above deficiency, needing a kind of steady fire performance reliably can improving nozzle, making premixed flame compared with having higher efficiency of combustion under underload, structure is simple, the nozzle of maintain and replace and be provided with the gas turbine of this nozzle.
Utility model content
(1) technical problem that will solve
The technical problems to be solved in the utility model there is provided the gas turbine that a kind of nozzle is provided with this nozzle, makes it possible to the steady fire performance reliably improving nozzle, makes premixed flame compared with having higher efficiency of combustion under underload, and structure is simple, maintain and replace.
(2) technical scheme
In order to solve the problems of the technologies described above, the utility model provides a kind of nozzle, comprises centerbody, annular wall and swirl-flow devices; Centerbody hybrid channel is provided with in described centerbody; The entrance point of described centerbody hybrid channel is provided with eddy flow orifice plate, and the port of export is provided with centerbody head end wall, and described centerbody head end wall is provided with collection chamber; Described annular wall is coaxially arranged on the periphery of centerbody, between described annular wall and centerbody, form peripheral hybrid channel; Described swirl-flow devices is positioned at the one end near centerbody import on described peripheral hybrid channel; Described centerbody is provided with premixed fuel passage and diffused fuel passage; Described premixed fuel passage is communicated with described centerbody hybrid channel by centerbody premixed fuel spray-hole; Described collection chamber is communicated with described centerbody hybrid channel by diffused fuel spray-hole; Described diffused fuel passage is communicated with collection chamber.
Wherein, described centerbody head end wall is provided with internal ring wall and external annulus, and described external annulus offers the end wall spray-hole be communicated with described peripheral hybrid channel, described diffused fuel spray-hole is positioned on internal ring wall; Described collection chamber between internal ring wall and external annulus, and is provided with baffle plate in collection chamber.
Wherein, described centerbody premixed fuel spray-hole, diffused fuel spray-hole and end wall spray-hole are straight hole or inclined hole.
Wherein, the axial length of described external annulus is greater than the axial length of internal ring wall.
Wherein, the perforated area of described centerbody premixed fuel spray-hole and diffused fuel spray-hole is than between 0.05-0.5.
Wherein, described swirl-flow devices comprises the swirl vane that centrally body circumference is arranged, and be provided with the blade interior passage with described premixed fuel channel connection in described swirl vane, described blade interior passage is provided with blade premixed fuel spray-hole.
Wherein, the inside of described centerbody hybrid channel is provided with contraction section and expansion segment, and described expansion segment is positioned at the downstream of contraction section.
Wherein, described eddy flow orifice plate is provided with multiple tangential hole.
Wherein, the axial location of described centerbody head end wall is in the axial range of annular wall.
Wherein, the utility model also provides a kind of gas turbine, and it comprises described nozzle.
(3) beneficial effect
Technique scheme of the present utility model has following beneficial effect: the utility model nozzle by arranging independently diffused fuel passage on centerbody, make part of fuel burner oil in the fuel-air mixture sprayed directly to centerbody hybrid channel near centerbody end wall place, final at jet expansion center forming section premixed combustion flame, thus manufacture the higher region of local temperature, and the fuel-air mixture that peripheral hybrid channel sprays is ignited, greatly can improve the steady fire performance of nozzle and ensure higher efficiency of combustion.The utility model structure is simple, easily realizes, and not by the restriction of combustion chamber miscellaneous part, the problem such as not to mate.
Detailed description of the invention
Below in conjunction with drawings and Examples, embodiment of the present utility model is described in further detail.Following examples for illustration of the utility model, but can not be used for limiting scope of the present utility model.
In description of the present utility model, except as otherwise noted, the implication of " multiple " is two or more; Term " on ", D score, "left", "right", " interior ", " outward ", " front end ", " rear end ", " head ", the orientation of the instruction such as " afterbody " or position relationship be based on orientation shown in the drawings or position relationship, only the utility model and simplified characterization for convenience of description, instead of the device of instruction or hint indication or element must have specific orientation, with specific azimuth configuration and operation, therefore can not be interpreted as restriction of the present utility model.In addition, term " first ", " second ", " the 3rd " etc. only for describing object, and can not be interpreted as instruction or hint relative importance.
In description of the present utility model, it should be noted that, unless otherwise clearly defined and limited, term " is connected ", " connection " should be interpreted broadly, such as, can be fixedly connected with, also can be removably connect, or connect integratedly; Can be mechanical connection, also can be electrical connection; Can be directly be connected, also indirectly can be connected by intermediary.For the ordinary skill in the art, concrete condition the concrete meaning of above-mentioned term in the utility model can be understood.
As Figure 1-5, the nozzle of the present embodiment comprises centerbody 1, annular wall 2 and swirl-flow devices 3; In centerbody 1, be provided with centerbody hybrid channel 23, the entrance point of centerbody hybrid channel 23 is provided with eddy flow orifice plate 10, and the port of export is provided with centerbody head end wall 5.Centerbody head end wall 5 is provided with collection chamber 9; Annular wall 2 is coaxially arranged on the periphery of centerbody 1, forms peripheral hybrid channel 24 between annular wall 2 and centerbody 1; Swirl-flow devices 3 is positioned at the one end (that is, near one end of eddy flow orifice plate 10) near centerbody 1 import on peripheral hybrid channel 24, for the formation of eddy flow; Centerbody 1 is provided with independently premixed fuel passage 12 and diffused fuel passage 17; The circumference of premixed fuel passage 12 centrally body 1 is set to many, and premixed fuel passage 12 is communicated with centerbody hybrid channel 23 by centerbody premixed fuel spray-hole 16; Collection chamber 9 is communicated with centerbody hybrid channel 23 by diffused fuel spray-hole 18; Diffused fuel passage 17 is communicated with collection chamber 9, and fuel can directly be entered in centerbody hybrid channel 23.
As shown in Figure 2, centerbody head end wall 5 is provided with internal ring wall 6 and external annulus 7, and the axial length of external annulus 7 is greater than the axial length of internal ring wall 6.External annulus 7 offers the end wall spray-hole 19 be communicated with peripheral hybrid channel 24, and diffused fuel spray-hole 18 is positioned on internal ring wall 6; Corresponding, collection chamber 9 between internal ring wall 6 and external annulus 7, and is provided with baffle plate 8 in collection chamber 9, and end wall spray-hole 19 is positioned at the downstream of baffle plate 8.
Preferably, centerbody premixed fuel spray-hole 16, diffused fuel spray-hole 18 and end wall spray-hole 19 is straight hole or inclined hole, and visual actual needs selects pass flexibly.Wherein, straight hole is the through hole offered vertically, inclined hole is the through hole offered with the direction vector of radial direction vertically, simultaneously, ignition fuel injections hole 15 and steady fiery fuel orifice 16 also for the tangential hole for making fuel be rotated through, certainly, can also can be the hole of other types, such as, bellmouth etc.
The centerbody premixed fuel spray-hole 16 of the present embodiment is positioned on the internal face 15 of premixed fuel passage 12, and the perforated area of centerbody premixed fuel spray-hole 16 and diffused fuel spray-hole 18 than between 0.05-0.5, thus reaches good premixing effect.
Shown in composition graphs 3, Fig. 4, swirl-flow devices 3 comprises the swirl vane 4 that centrally body 1 circumference is arranged, swirl vane 4 is hollow, is provided with the blade interior passage 13 be communicated with premixed fuel passage 12 in swirl vane 4, and blade interior passage 13 is provided with blade premixed fuel spray-hole 14.
And, the inside of centerbody hybrid channel 23 is provided with contraction section 20 and expansion segment 21, contraction section 20 shrinks gradually to the direction of outlet from import and diminishes, expansion segment 21 is expanded gradually to the direction of outlet from import and is become large, expansion segment 21 is positioned at the downstream of contraction section 20, that is, expansion segment 21 is near centerbody head end wall 5.
Eddy flow orifice plate 10 is provided with multiple tangential hole 11, and tangential hole 11 is communicated with centerbody hybrid channel 23.And the axial location of centerbody head end wall 5 is positioned within the axial range of annular wall 2, that is, centerbody head end wall 5 is in inside the coated scope of annular wall 2.
The utility model also provides a kind of gas turbine, and it comprises described nozzle, and this nozzle application is on combustion chamber.
Operation principle of the present utility model is: first, and extraneous air forms eddy flow respectively by swirl-flow devices 3 and eddy flow orifice plate 10 and enters peripheral hybrid channel 24 and centerbody hybrid channel 23; Then, fuel enters blade interior passage 13 and centerbody premixed fuel spray-hole 16 respectively by premixed fuel passage 12; Wherein a part of fuel is by spraying in the blade premixed fuel spray-hole 14 on blade interior passage 13 to the periphery hybrid channel 24 and mixing with air, meanwhile, another part fuel is sprayed by centerbody premixed fuel spray-hole 16 and mixes with air in centerbody hybrid channel 23; Independently diffused fuel passage 17 is had in centerbody 1, the fuel flow further downstream of diffused fuel passage 17 enters the collection chamber 9 offered in centerbody 1, internal ring wall 6 have diffused fuel spray-hole 18 and be communicated with collection chamber 9, make fuel can be directly injected in the fuel-air mixture of centerbody hybrid channel 23, the gas of forming section premix, then enters burner inner liner and carries out partly-premixed burning.As shown in Figure 5, core premixed flame 25 is formed in nozzle center, core premixed flame 25 can manufacture the higher region of local temperature, and the fuel-air mixture of peripheral hybrid channel 24 of igniting, form peripheral premixed flame 26, the steady fire performance of nozzle can be drastically increased and ensure higher efficiency of combustion.
And inside, centerbody hybrid channel 23 is provided with contraction section 20, expansion segment 21, and expansion segment 21 is in contraction section 20 downstream, that is, centerbody hybrid channel 23 is contraction-expanding channel; Venturi 22 is formed between contraction section 20 and expansion segment 21, contraction section 20 in centerbody hybrid channel 23 can improve the jet velocity of fuel-air mixture, it reaches maximum at venturi 22 place, utilizes venturi 22 that core premixed flame 25 can be prevented to tempering in centerbody hybrid channel 23; And expansion segment 21 can carry out water conservancy diversion to fuel-air mixture, prevents fuel-air mixture to be separated.Meanwhile, external annulus 7 has end wall spray-hole 19 in baffle plate 8 downstream, and end wall spray-hole 19 is communicated with peripheral hybrid channel 24, and part of fuel air Mixture is sprayed from end wall spray-hole 19, has certain cooling effect by baffle plate 8.
As shown in Figure 5, the final effect formed is the centre of jet expansion is partly-premixed combustion flame, and peripheral is premixed combustion flame, and under the effect of partly-premixed burning, under comparatively underload, the flame holding of nozzle and efficiency of combustion are greatly improved; Along with the rising of load, due to the increase of inlet temperature, outlet temperature and fuel-air mixture equivalent proportion, stability and the efficiency of combustion of premixed flame reach higher level, and in order to reach lower discharge, now can close diffused fuel passage 17, only have premixed fuel passage 12 to supply fuel, nozzle adopts the pattern of full premix combustion.
In sum, the utility model nozzle by arranging independently diffused fuel passage on centerbody, make part of fuel burner oil in the fuel-air mixture sprayed directly to centerbody hybrid channel near centerbody end wall place, final at jet expansion center forming section premixed combustion flame, thus manufacture the higher region of local temperature, and the fuel-air mixture that peripheral hybrid channel sprays is ignited, greatly can improve the steady fire performance of nozzle and ensure higher efficiency of combustion.The utility model structure is simple, easily realizes, and not by the restriction of combustion chamber miscellaneous part, the problem such as not to mate.
Embodiment of the present utility model provides for the purpose of example and description, and is not exhaustively or by the utility model be limited to disclosed form.Many modifications and variations are apparent for the ordinary skill in the art.Selecting and describing embodiment is in order to principle of the present utility model and practical application are better described, and enables those of ordinary skill in the art understand the utility model thus design the various embodiments with various amendment being suitable for special-purpose.