Background technology
Day by day serious along with environmental pollution, the requirement of environmental regulation with perform also more and more stricter.N in air
2with O
2chemically reactive and the initial temperature that generates NOx is about 1650 °, when chamber temperature is higher than 1650 °, just has NOx and produces.For traditional diffusion combustion combustion chamber, the flame front temperature of diffusion combustion mode always equals the theoretical temperature combustion that stoichiometric ratio is 1, its dense or rare and different not because of fuel and the total Blend proportion of air, although this theoretical temperature combustion is slightly different because fuel element is different, but always higher than 1650 °, the thus NO of conventional diffusion combustion chamber
xdischarge capacity is always very high.Modern dry low NO_x combustor adopts the mode of premixed combustion, effectively can reduce pollutant emission.The general principle of dry low NO_x combustor design is: fuel and air are pre-mixed as homogeneous phase, the flammable mixture that dilutes, and make it burn in the mode of flame propagation, so that flame temperature is controlled below 1650 °, thus the growing amount of reduction NOx.
The danger that of facing in premixed combustion combustion chamber is very large is tempering.Owing to there are some destabilizing factors in combustion process, when flame propagation velocity is greater than the flow velocity of fuel-air mixture, flame can upstream propagate into Fuel-air pre-mixing zone from combustion zone, this can cause nozzle even other structures of head be burned, and then cause gas turbine work to stop.Anti-backfire effective means is very limited, from the patent announced at present, mainly contains three kinds of principles: the first reduces tempering by designing suitable structure optimization flowing.The second monitors combustion position in real time by sensor, when there is tempering, realizes the ACTIVE CONTROL to tempering by change combustion mode or change fuel flow path.The third is the hot fuse attribute utilizing material, such as, install thermal cutoff device, and when there is tempering, thermal cutoff device melts, and changes fuel flow path thus prevents going deep into of tempering.For different combustion chambers, due to the specific requirement of nozzle arrangements and function, the use of fireproof tempering device has certain limitation.
The first principle can pre-anti-backfire to a certain extent, but prevention of having no idea when tempering occurs.The second principle needs placement sensor, makes the control of combustion chamber more complicated.Utilize the third principle can design easy reliable fireproof tempering device.The such as patent US005685139A of GE company, by the wall thickness reduction by nozzle tip ad-hoc location, when tempering occurs; first thin-walled portion is burned thus changes fuel flow path; fuel flow path changes, and correspondingly have also been changed combustion mode, tempering is stoped in time.But nozzle tip is burnt in anti-backfire process, nozzle tip is caused to be scrapped.Because nozzle arrangements is complicated, manufacture and maintenance difficulty high, gas turbine user often needs to buy or maintenance nozzle to specific supplier or maintenance provider, not only expensive, and the cycle is long.
In view of the defect of above-mentioned prior art, need to provide a kind of and can protect head construction and the anti-backfire nozzle for gas-turbine combustion chamber of reduction pollutant emission.
Utility model content
(1) technical problem that will solve
The technical problems to be solved in the utility model now passes through the wall thickness reduction of nozzle tip ad-hoc location in the art, and when tempering occurs, first thin-walled portion is burned thus changes fuel flow path.But nozzle tip is burnt in anti-backfire process, nozzle tip is caused to be scrapped.Because nozzle arrangements is complicated, manufacture and maintenance difficulty high, gas turbine user often needs to buy or maintenance nozzle to specific supplier or maintenance provider, not only expensive, and the problem that the cycle is long.
(2) technical scheme
In order to solve the problems of the technologies described above, the utility model provides a kind of anti-backfire nozzle for gas-turbine combustion chamber, comprises flange, cyclone and centerbody; Described flange is provided with fuel inlet, the axial fuel passage be communicated with described fuel inlet is provided with in described centerbody, described cyclone is provided with swirl vane, described swirl vane is provided with the radial fuel passage be communicated with described axial fuel passage, described radial fuel passage is provided with fuel outlet, described centerbody is provided with fireproof tempering device.
Further, described centerbody comprises main paragraph and tip section, and described tip section one end is connected with described main paragraph, and the other end is provided with end face, described end face is provided with the most advanced and sophisticated fuel outlet that can be communicated with described axial fuel passage, described fireproof tempering device is arranged in described tip section.
Further, described tip section is bellows, and described fireproof tempering device comprises the first seal section and the second seal section, and described second seal section one end is fixedly connected with described bellows, the other end is connected with described first seal section, and described first seal section corresponds to described most advanced and sophisticated fuel outlet and arranges.
Further, described second seal section can moving axially along described axial fuel passage, and make to form fuel between described second seal section and described first seal section and stitch, described most advanced and sophisticated fuel outlet stitches with described fuel and is communicated with.
Further, the total length of described bellows is 20 ~ 200mm.
Further, the wall thickness of described bellows is 0.5 ~ 3mm.
Further, described flange is also provided with air intlet, in described centerbody, is provided with the air duct be communicated with described air intlet, described end face is provided with the air outlet slit be communicated with described air duct.
Further, described air outlet slit and described most advanced and sophisticated fuel outlet interlaced arrangement.
Further, the gross area of described most advanced and sophisticated fuel outlet is 20% ~ 50% of the fuel outlet gross area on cyclone.
(3) beneficial effect
Technique scheme tool of the present utility model has the following advantages: the utility model provides on a kind of flange in the anti-backfire nozzle of gas-turbine combustion chamber and is provided with fuel inlet, the axial fuel passage be communicated with fuel inlet is provided with in centerbody, cyclone is provided with swirl vane, swirl vane is provided with the radial fuel passage be communicated with axial fuel passage, radial fuel passage is provided with fuel outlet, centerbody is provided with fireproof tempering device.The utility model provide for being provided with fireproof tempering device in the anti-backfire nozzle of gas-turbine combustion chamber, combustion mode becomes diffusion combustion from premixed combustion, can flame be stoped in time to spread head like this, protect head construction.After combustion mode changes, the continuation that can not affect combustion chamber runs; Thus effectively reduce the operation and maintenance cost of gas-turbine combustion chamber; After tempering is stoped smoothly, combustion mode also reverts to premixed combustion, can reduce pollutant emission.
Detailed description of the invention
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 ", the orientation of the instruction such as " outward " 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 machine 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 description of the present utility model, it should be noted that, unless otherwise clearly defined and limited, term " installation ", " being connected ", " connection " should be interpreted broadly, and 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.
Below in conjunction with drawings and Examples, detailed description of the invention of the present utility model is described in further detail.Following examples for illustration of the utility model, but are not used for limiting scope of the present utility model.
As shown in Figures 1 to 5, a kind of anti-backfire nozzle for gas-turbine combustion chamber that the utility model provides, comprises flange 1, cyclone 2 and centerbody 3; Described flange 1 is provided with fuel inlet 11, the axial fuel passage 312 be communicated with described fuel inlet 11 is provided with in described centerbody 3, described cyclone 2 is provided with swirl vane 21, in the cavity that swirl vane 21 is formed between cyclone 2 and centerbody 3.Swirl vane 21 described in the present embodiment is provided with the radial fuel passage 22 be communicated with described axial fuel passage 312, described radial fuel passage 22 is provided with fuel outlet 23.In the cavity that also can be formed between cyclone 2 and centerbody 3, independent radial fuel passage 22 is set along the vertical direction, radial fuel passage 22 and left and right to axial fuel passage 312 be communicated with.Described centerbody 3 is provided with fireproof tempering device 320.
The utility model provide for being provided with fireproof tempering device in the anti-backfire nozzle of gas-turbine combustion chamber, combustion mode becomes diffusion combustion from premixed combustion.After combustion mode changes, the continuation that can not affect combustion chamber runs, but diffusion combustion pollutant emission is high.When tempering disappears completely, when combustion chamber returns to normal combustion operating mode, nozzle tip temperature reduces, and bellows 323 is contracted to original shape, and the first seal section and the second seal section are fitted, and combustion mode becomes the lower premixed combustion of pollutant emission again by diffusion combustion.The benefit of this design is: can effectively stop when anti-backfire occurs, and not defective nozzle structure, thus effectively reduce the operation and maintenance cost of gas-turbine combustion chamber; After tempering is stoped smoothly, combustion mode also reverts to premixed combustion, can reduce pollutant emission.The utility model can stop flame to spread head in time, protects head construction.After combustion mode changes, the continuation that can not affect combustion chamber runs; Thus effectively reduce the operation and maintenance cost of gas-turbine combustion chamber; After tempering is stoped smoothly, combustion mode also reverts to premixed combustion, can reduce pollutant emission.
What the utility model provided comprises main paragraph 31 and tip section 32 for the described centerbody 3 in gas-turbine combustion chamber, described fireproof tempering device 320 is arranged in described tip section 32, described tip section 32 one end is connected with described main paragraph 31, the other end is provided with end face, described end face is provided with the most advanced and sophisticated fuel outlet 326 that can be communicated with described axial fuel passage 312.It is to be noted that the utility model proposes a kind of most advanced and sophisticated fuel outlet 326 and axial fuel passage 312 by completely cutting off the implementation transformed between being communicated with under Annealed Strip under normal operation, but it should be noted that other similar transform modes are also within protection domain of the present utility model.
Tip section 32 described in the present embodiment is bellows 323, described fireproof tempering device 320 comprises the first seal section 324 and the second seal section 325, described second seal section 325 one end is fixedly connected with described bellows 323, the other end is connected with described first seal section 324, and described first seal section 324 corresponds to described most advanced and sophisticated fuel outlet 326 and arranges.First seal section 324 is vertically arranged on the inwall of described axial fuel passage 312, and the axis of the second seal section 325 fuel channel 312 vertically, namely left and right directions is arranged on bellows 323.The expansion displacement amount that bellows 323 produces is relevant with bellows 323 overall length.Bellows 323 is longer, and fuel during tempering between the first seal section 325 and the second seal section 325 stitches 327 larger.In order to ensure that bellows 323 can produce enough expansions when tempering, preferably, bellows 323 total length scope is 20 ~ 200mm.In order to ensure that bellows 323 has enough intensity, preferably, bellows 323 wall thickness range is 0.5 ~ 3mm.
Described second seal section 325 can moving axially along described axial fuel passage 312, and make to form fuel between described second seal section 325 and described first seal section 324 and stitch 327, described most advanced and sophisticated fuel outlet 326 stitches 327 with described fuel and is communicated with.
When tempering occurs, high temperature causes bellows 323 to expand, and most advanced and sophisticated fuel outlet 326 is communicated with axial fuel passage 312, and gaseous fuel sprays from most advanced and sophisticated fuel outlet 326.Because the fuel flow rate flowing through nozzle is certain, when a part of gaseous fuel sprays from most advanced and sophisticated fuel outlet 326, in the fuel-air mixture that cyclone produces, the concentration of fuel will decline, flammable reduction.On the other hand, the gaseous fuel sprayed from most advanced and sophisticated fuel outlet 326 and ambient air produce diffusion combustion.The stability of diffusion combustion is better, so the mode of operation of combustion chamber is converted into diffusion combustion by premixed combustion, prevents back fire flame in time to spread head.When tempering disappears completely, when combustion chamber returns to normal combustion operating mode, nozzle tip section 32 temperature reduces, bellows 323 is contracted to original shape, now, most advanced and sophisticated fuel outlet 326 is separated with axial fuel passage 312, and fuel only sprays from the fuel outlet 23 cyclone 2, and mode of operation during burning goes back to the lower premixed combustion of pollutant emission by diffusion combustion.Tempering can be stoped in time by the automatic switchover of combustion chamber mode, and farthest reduce the discharge of the pollutant that diffusion combustion brings.
In order to flame under preventing normal running conditions adheres in nozzle tip section 32, described flange 1 is also provided with air intlet 12, be provided with the air duct 311 be communicated with described air intlet 12 in described centerbody 3, described end face be provided with the air outlet slit 322 be communicated with described air duct 311.Carry out air and flow through air duct 311 by air intlet 12, spray at air outlet slit 322, thus tip section 32 is blown clearly.During in order to ensure tempering, blowing clearly air and not affecting diffusion combustion, preferably, air outlet slit 322 and most advanced and sophisticated fuel outlet 326 interlaced arrangement.
During in order to ensure tempering, premixed combustion is to the smooth switching of diffusion combustion, and preferably, the gross area of most advanced and sophisticated fuel outlet 326 is 20% ~ 50% of fuel outlet 23 gross area on cyclone 2.Under fuel-air mixture flammable conditions, the scope of equivalent proportion is generally 0.4 ~ 2, and the fuel-air mixture equivalent proportion of premixed combustion design is generally about 0.5.When the gross area of most advanced and sophisticated fuel outlet 326 is 20% ~ 50% of fuel outlet 23 gross area on cyclone 2, fuel-air mixture equivalent in cyclone 2 is dropped to less than 0.4 possibility larger.
When the utility model is used for the anti-backfire nozzle use of gas-turbine combustion chamber, from the gaseous fuel of fuel inlet 11 on flange 1, spray at fuel outlet 23 after axial fuel passage 312 and radial fuel passage 22, and mix with the air from cyclone 2 upstream, utilize the fireproof tempering device of the principle design of bellows expanded by heating, when there is tempering, bellows 323 expands and causes the first seal section 324 to be separated with the second seal section 325, fuel flows through most advanced and sophisticated fuel outlet to nozzle downstream by the fuel seam 327 between two sections, combustion mode becomes diffusion combustion from premixed combustion, can flame be stoped in time to spread head like this, protect head construction.
In sum, the utility model has the following advantages: the utility model provides on a kind of flange in the anti-backfire nozzle of gas-turbine combustion chamber and is provided with fuel inlet, the axial fuel passage be communicated with fuel inlet is provided with in centerbody, cyclone is provided with swirl vane, swirl vane is provided with the radial fuel passage be communicated with axial fuel passage, radial fuel passage is provided with fuel outlet, centerbody is provided with fireproof tempering device.The utility model provide for being provided with fireproof tempering device in the anti-backfire nozzle of gas-turbine combustion chamber, combustion mode becomes diffusion combustion from premixed combustion, can flame be stoped in time to spread head like this, protect head construction.After combustion mode changes, the continuation that can not affect combustion chamber runs; Thus effectively reduce the operation and maintenance cost of gas-turbine combustion chamber; After tempering is stoped smoothly, combustion mode also reverts to premixed combustion, can reduce pollutant emission.
In addition, the anti-backfire nozzle for gas-turbine combustion chamber of the present utility model adheres in nozzle tip section to prevent flame under normal running conditions, flange is also provided with air intlet, is provided with the air duct be communicated with air intlet in centerbody.
Above embodiment only in order to the technical solution of the utility model to be described, is not intended to limit; Although be described in detail the utility model with reference to previous embodiment, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein portion of techniques feature; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the spirit and scope of each embodiment technical scheme of the utility model.