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 premixing nozzle is burnt, for reaching extremely low disposal of pollutants, flame is operated near flammable border and the fuel-air mixture body effluxvelocity that ejects of nozzle is larger, the reliable ignition of combustion chamber is more difficult, in prior art solution normally centerbody axial length be less than the length of premixing nozzle outside wall surface, fuel-air mixture body 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 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, consider that to enter remaining of recirculating zone not fire-hazardous, the fuel-air mixture that equivalent proportion is lower, still there is successful risk of can not lighting a fire in combustion chamber.
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 premixing nozzle export center body to flow, form recirculation eddy current, decrease the air capacity be ejected in recirculating zone, thus reduce effluxvelocity near premixing nozzle outlet, improve flame holding.From air angle, this premixing nozzle just improves the stability in local return district, just there is certain effect to the stable of flame, reliably can not improve the ignition performance of premixing nozzle, and 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, need a kind of premixing nozzle and the gas turbine that improve ignition performance.
Utility model content
(1) technical problem that will solve
The technical problems to be solved in the utility model there is provided a kind of premixing nozzle and gas turbine, and this premixing nozzle effectively can improve ignition performance.
(2) technical scheme
In order to solve the problems of the technologies described above, the utility model provides premixing nozzle to comprise centerbody, annular inner wall and swirl-flow devices, described annular inner wall is coaxially arranged on the periphery of centerbody, described swirl-flow devices is between centerbody and annular inner wall, the periphery of described annular inner wall is coaxially provided with annular outer wall, forms diffused fuel passage between described annular inner wall and annular outer wall; Described diffused fuel passage is communicated with collection chamber, described annular inner wall is provided with steady fiery bluff body, described collection chamber is communicated with ignition fuel injections hole and steady fiery fuel orifice, described ignition fuel injections hole is towards the ignition zone of burner inner liner, and described steady fiery fuel orifice is towards the downstream area of steady fiery bluff body.
Wherein, described collection chamber is surrounded by jet expansion end wall and jet expansion internal ring wall; Described jet expansion internal ring wall is between jet expansion end wall and steady fiery bluff body; Described ignition fuel injections hole is opened on jet expansion end wall, and described steady fiery fuel orifice is opened on jet expansion internal ring wall.
Wherein, described centerbody end is provided with centerbody head end wall, and described centerbody head end wall is provided with center air spray-hole; Described steady fiery bluff body is positioned at the downstream of centerbody head end wall.
Wherein, the circumference of described steady fiery bluff body annularly inwall is arranged, and the circumferential scope of steady fiery bluff body is not more than 1/2nd of annular inner wall circumference.
Wherein, the shape of cross section of described steady fiery bluff body is triangle or rectangle or trapezoidal or circular arc.
Wherein, the circumferential scope that described ignition fuel injections hole and steady fiery fuel orifice are offered all is no more than the circumferential scope of steady fiery bluff body.
Wherein, described ignition fuel injections hole and steady fiery fuel orifice are straight hole or inclined hole.
Wherein, the perforated area of described ignition fuel injections hole and steady fiery fuel orifice is than between 0.5-10.
Wherein, described swirl-flow devices comprises the swirl vane that centrally body circumference is arranged, described swirl vane is provided with blade interior passage, and described blade interior passage is provided with teasehole, is provided with the premixed fuel passage with described blade interior channel connection in described centerbody.
The utility model also provides a kind of gas turbine, and it comprises described premixing nozzle.
(3) beneficial effect
Technique scheme of the present utility model has following beneficial effect: the utility model provides a kind of premixing nozzle, by arranging independently diffused fuel passage on premixing nozzle ring wall, make part of fuel be directly injected into into burner inner liner from ignition fuel injections hole, drastically increase the ignition performance of premixing nozzle; And, by arranging bluff body structure at nozzle on the annular inner wall face in exit, thus form stable recirculating zone, and diffused fuel channel middle divides fuel can be directly injected into recirculating zone after bluff body, form stable steady flame range territory, the position in its next-door neighbour ignition fuel injections hole, substantially increases the stability of flame, and further increases the ignition performance of nozzle.This premixing nozzle 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 present embodiment premixing nozzle comprises centerbody 1, annular inner wall 2 and swirl-flow devices 4, annular inner wall 2 is coaxially arranged on the periphery of centerbody 1, swirl-flow devices 4 between centerbody 1 and annular inner wall 2 and near one end of centerbody 1 import, for generation of rotational flow air; And, be coaxially provided with annular outer wall 3 in the periphery of annular inner wall 2, and form diffused fuel passage 11 between annular inner wall 2 and annular outer wall 3; And diffused fuel passage 11 is communicated with collection chamber 14.Meanwhile, annular inner wall 2 is provided with steady fiery bluff body 7, and this collection chamber 14 is positioned at the terminal position of premixing nozzle, and is communicated with ignition fuel injections hole 15 and steady fiery fuel orifice 16.Wherein, ignition fuel injections hole 15 towards burner inner liner ignition zone (namely, the opening direction in ignition fuel injections hole 15 and the axial consistent of this premixing nozzle), corresponding, steady fiery fuel orifice 16 is towards the downstream area (that is, the opening direction of steady fiery fuel orifice 16 is consistent with the radial direction of premixing nozzle) of steady fiery bluff body 7.
As shown in Figure 2, collection chamber 14 is surrounded by jet expansion end wall 8 and jet expansion internal ring wall 9, and is positioned at the end of premixing nozzle.Wherein, jet expansion internal ring wall 9 is between jet expansion end wall 8 and steady fiery bluff body 7.And steady fiery fuel orifice 16 is opened on jet expansion internal ring wall 9, and make steady fiery fuel orifice 16 towards the downstream area of steady fiery bluff body 7; Meanwhile, ignition fuel injections hole 15 is opened on jet expansion end wall 8, and makes ignition fuel injections hole 15 towards the ignition zone of burner inner liner.
Steady fiery fuel orifice 16 can make part of fuel be directly injected into low regime, local into steady fiery bluff body 7 downstream or recirculating zone, thus form the fuel rich area of local, the diffusion flame that the fuel more easily sprayed by ignition fuel injections hole 15 is formed ignites, and flame can be stabilized in this region form bluff body after steady flame range 17.
In addition, centerbody 1 end is provided with centerbody head end wall 6, and centerbody head end wall 6 is provided with center air spray-hole 18; The steady position of fiery bluff body 7 between centerbody head end wall 6 and jet expansion end wall 8.Certainly, the form of center air spray-hole 18 can be straight hole, inclined hole and tangential hole.
For steady fiery bluff body 7, as shown in Figure 3, Figure 4, it can the circumference of annularly inwall 2 be arranged, and the circumferential scope of steady fiery bluff body 7 is not more than 1/2nd of annular inner wall 2 circumference.That is, steady fiery bluff body 7 is the distribution in arcuation on annular inner wall 2, and this arc length is not more than 1/2nd of annular inner wall 2 circumference, and in other words, the angle of steady fiery bluff body 7 correspondence is between (-90 ° ~+90 °).
And, multiple ignition fuel injections hole 15 and steady fiery fuel orifice 16 are circumferentially arranged too, the circumferential scope that both offer all is no more than the circumferential scope of steady fiery bluff body 7, that is, the arrangement scope of ignition fuel injections hole 15 and steady fiery fuel orifice 16 drops within the circumferential scope of steady fiery bluff body 7.
Preferably, the shape of cross section of steady fiery bluff body 7 is triangle or rectangle or trapezoidal or circular arc.Certainly, the steady fiery bluff body 7 of other shapes also belongs to protection domain of the present utility model.
Further, ignition fuel injections hole 15 and steady fiery fuel orifice 16 can be straight hole or inclined hole, wherein, straight hole is the through hole offered vertically, and 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.
In addition, the perforated area of ignition fuel injections hole 15 and steady fiery fuel orifice 16, than between 0.5-10, can meet the demand of igniting and steady fire within the scope of this.
Wherein, swirl-flow devices 4 comprises the swirl vane 5 that centrally body 1 circumference is arranged, swirl vane 5 is provided with blade interior passage 12, and is provided with teasehole 13 on blade interior passage 12, is provided with the premixed fuel path 10 be communicated with blade interior passage 12 in centerbody 1.
In addition, the utility model also provides a kind of gas turbine, and it comprises described premixing nozzle, and this premixing nozzle when mounted, need ensure that the side at steady fiery bluff body 7 place is just to the installation site of igniter 21 on burner inner liner wall 20, i.e. steady fiery bluff body 7 side of installing near igniter 21.
Operation principle of the present utility model is as follows: first, fuel enters in the collection chamber 14 of jet expansion end wall 8 by the independently diffused fuel passage 11 that annular inner wall 2 and annular outer wall 3 are formed, fuel is divided into two strands from collection chamber 14, these two strands of fuel are not all pre-mixed with air, and wherein one is directly injected into into burner inner liner by the ignition fuel injections hole 15 offered on jet expansion end wall 8; The annular inner wall 2 of jet expansion end wall 8 upstream is provided with steady fiery bluff body 7, low regime or the recirculating zone of local can be formed in the downstream of steady fiery bluff body 7, be provided with jet expansion internal ring wall 9 between jet expansion end wall 8 and steady fiery bluff body 7, another strand of fuel is directly injected into into this low regime, local or recirculating zone by the steady fiery fuel orifice 16 offered on jet expansion internal ring wall 9.
As shown in Figure 5, premixing nozzle 19 when mounted, ensure that the side at steady fiery bluff body 7 place is just to the installation site of igniter 21 on burner inner liner wall 20, i.e. steady fiery bluff body 7 side of installing near igniter 21, the circumferential scope of ignition fuel injections hole 15 and steady fiery fuel orifice 16 is all no more than the circumferential scope of steady fiery bluff body 7, the fuel that ignition fuel injections hole 15 is ejected is more near igniter 21, and fuel is not pre-mixed with air, fuel is more easily lighted by the spark 22 that igniter 21 manufactures.
The fuel that is not pre-mixed with air of part is directly injected into low regime, local into steady fiery bluff body 7 downstream or recirculating zone from steady fiery fuel orifice 16, form the fuel rich area of local, more easily ignited by the diffusion flame that the fuel that ignition fuel injections hole 15 sprays is formed, and flame can be stabilized in this region, steady flame range 17 after forming bluff body.
The space that air is limited by centerbody 1 and annular inner wall 2 flows to nozzle interior, and the air-flow of rotational flow is formed through swirl-flow devices 4, fuel enters the blade interior passage 12 swirl vane 5 from premixed fuel path 10, and spouting from the premixed fuel spray-hole 13 of blade interior passage 12 setting; The position mixing residing for swirl-flow devices 4 of air and fuel, fuel-air mixture is ignited in the low regime in steady fiery bluff body 7 downstream or recirculating zone, forms stable premixed flame, until the fuel-air blender of premixing nozzle 19 is all ignited, and be stabilized in specific position, light a fire successfully.
Light a fire successfully, according to the actual requirement of flame stabilization and disposal of pollutants, optionally can close diffused fuel passage 11; Meanwhile, the center air spray-hole 18 that centerbody 1 is offered in head end wall 6 is free air-flow to go out, to reach the cooling effect to wall herein.
In sum, the utility model provides a kind of premixing nozzle, by arranging independently diffused fuel passage on premixing nozzle ring wall, making part of fuel be directly injected into into burner inner liner from ignition fuel injections hole, drastically increasing the ignition performance of premixing nozzle; And, by arranging bluff body structure at nozzle on the annular inner wall face in exit, thus form stable recirculating zone, and diffused fuel channel middle divides fuel can be directly injected into recirculating zone after bluff body, form stable steady flame range territory, the position in its next-door neighbour ignition fuel injections hole, substantially increases the stability of flame, and further increases the ignition performance of nozzle.This premixing nozzle 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.