A kind of micro-oil ignition rotational flow coal powder burner that prevents the slagging scorification of one-level combustion chamber
Technical field
The present invention relates to a kind of swirling pulverized coal combustion device that prevents the slagging scorification of one-level combustion chamber.
Background technology
Large-sized station boiler is huge with oil mass in igniting and low-load combustion-stabilizing process, electricity power enterprise is in order to save fuel oil, the fuel-economizing emphasis turns to ignition of the boiler and furnace shutting down process (oil consumption accounts for 60% during the boiler of power plant start and stop, and the low-load combustion-stabilizing oil consumption accounts for 40%) by the low-load combustion-stabilizing process.Turbulent burner occupies certain ratio at China's station boiler and other coal dust application.Adopt the large coal powder boiler of turbulent burner that its unique advantage is arranged: the thermal deviation that at first can avoid the superheater district to produce; Next is that the burner hearth shape is not had strict requirement.Along with China's unit day by day to the development of big capacity, the development of spiral-flow powdered coal burning technology has been proposed urgent requirement.Therefore, research micro-oil ignition rotational flow combustion technology all is that crucial meaning is arranged to the development of China's power industry and whole national economy.According to traditional approach, torch oil gun is arranged in the overfiren air port of burner, the distance of oil gun and coal dust spout is distant, and these two strands of air-flows are parallel to each other again, therefore when igniting, it is fewer that the heat of fuel oil generation is directly used in the part that heats coal dust, and heat utilization ratio is low, and the consumption of fuel oil is very big when making ignition of the boiler.The tiny-oil ignition technology is that a kind of boiler of power plant that is applied to starts, stops and the new method of low-load combustion-stabilizing.So-called tiny-oil ignition technology is meant the less oil gun of exerting oneself is arranged in wind snout, with the part dense primary wind and powder air-flow of a spot of oil drop combustion after deep or light separation, usually the method that adopts the big fire of little fire point to amplify is gradually lighted whole general mood stream and burner hearth at last.
Existing micro-oil ignition rotational flow burner all has characteristics separately, but has some shortcoming and defect simultaneously again.Publication number is CN 101093077A, open day be that the Chinese invention patent on December 26th, 2007 discloses " a kind of eddy flow powdered coal burner lit up by tiny oil ", described burner has been realized the level Four ignition process of little fire point big fire, and concentrate the deep or light separation that ring has been realized a wind by water conservancy diversion, also can regulate the length of flame, width and combustion intensity in the precombustion chamber by center wind.Because logical center wind in its sleeve pipe, coal powder density reduces, the heat that the igniting back produces is used for adding thermal center (-tre) wind rather than coal dust greatly, oil gun sleeve outlet temperature has only 1100 ℃-1500 ℃ like this, temperature levels is lower, required coal powder ignition heat increases, and the ignition oil amount is big, is difficult for lighting coal dust.In addition, because the oil gun sleeve of described burner and the distance between the one-level combustion chamber are zero or the oil gun sleeve inserts inside, one-level combustion chamber, during the wind of obstructed center, breeze airflow can form bigger recirculating zone in the inside of one-level combustion chamber; Behind the wind of logical center,, form slagging scorification but still can in the one-level combustion chamber, understand though the recirculating zone that forms reduces to some extent.
Summary of the invention
The purpose of this invention is to provide a kind of micro-oil ignition rotational flow coal powder burner that prevents the slagging scorification of one-level combustion chamber, in the combustion chamber, be easy to generate slagging scorification when solving existing eddy flow powdered coal burner lit up by tiny oil burning and at low-load combustion-stabilizing situation down-firing with the big problem of oil mass.
The present invention solves the problems of the technologies described above the technical scheme of taking to be: a kind of micro-oil ignition rotational flow coal powder burner of one-level combustion chamber slagging scorification that prevents of the present invention comprises air channel, concentrated ring, one-level combustion chamber, secondary combustion chamber, interior cyclone, interior secondary wind air channel, outer secondary wind air channel, nozzles, the 3rd wind channel tube, second wind channel tube, first wind channel tube and main oil gun one time; Described burner also comprises outer cyclone, three grades of combustion chambers, second gripper shoe, first gripper shoe and sleeve pipes; It in described first wind channel tube air channel, the port of export of first wind channel tube is fixed with nozzles, concentrated ring is fixed in first wind channel tube, and the diameter that concentrates ring concentrates ring 2 directions towards nozzles along this and reduces gradually, the front end of described sleeve pipe is an openend, the rear end of sleeve pipe is a blind end, the front end of sleeve pipe passes first wind channel tube and is packed in the concentrated ring, described one-level combustion chamber is fixed in first wind channel tube of sleeve pipe front end by first gripper shoe, described secondary combustion chamber is fixed in first wind channel tube of one-level chamber front end by second gripper shoe, in first wind channel tube of secondary combustion chamber's front end three grades of combustion chambers, the rear end that one end of described main oil gun passes sleeve pipe is fixed in the sleeve pipe, the port of export of main oil gun is corresponding with the arrival end of one-level combustion chamber, second wind channel tube is solidly set on first wind channel tube and is positioned at the front end of first wind channel tube, it between second wind channel tube and first wind channel tube interior secondary wind air channel, interior cyclone is fixed in the interior secondary wind air channel, the 3rd wind channel tube is solidly set on second wind channel tube and is positioned at the front end of second wind channel tube, it between the 3rd wind channel tube and second wind channel tube outer secondary wind air channel, outer cyclone is fixed in the outer secondary wind air channel, the axial distance of the mouth of pipe of sleeve pipe front end and one-level entry of combustion chamber is b, the front end of sleeve pipe produces the recirculating zone, the preceding border of described recirculating zone is a to the axial distance of the mouth of pipe of sleeve pipe front end, the axial distance b between the mouth of pipe of described sleeve pipe front end and the one-level entry of combustion chamber greater than preceding border, recirculating zone to the axial distance a between the mouth of pipe of sleeve pipe front end.
The invention has the beneficial effects as follows: one, stuffy in the sleeve pipe, one time wind will produce the recirculating zone at the sleeve pipe front end before entering the one-level combustion chamber, preceding border, recirculating zone to the axial distance of the sleeve pipe front end mouth of pipe is a, among the present invention, having length between the front end mouth of pipe of sleeve pipe and the one-level entry of combustion chamber is the spacing of b, and guarantee b>a, the one-level combustion chamber can not involved in the recirculating zone of Chan Shenging like this, coal dust can not produce slagging scorification and (use the large-size rotational flow coal powder fired boiler burner of bituminous coal for a 600MW when the internal combustion of one-level combustion chamber, when adopting the turbulent burner of prior art, in real work, produce serious slagging scorification in the one-level combustion chamber, and adopt burner of the present invention, the slagging scorification problem that do not exist in service).Two, among the present invention, obstructed center wind in the sleeve pipe, coal powder density can not reduce, thermal-flame is directly lighted the coal dust of high concentration, burning will be very abundant, flame stabilization, the outlet temperature of sleeve pipe front end is 1600 ℃-2000 ℃, the ignition oil amount is little, (when the large-size rotational flow coal powder fired boiler burner that uses bituminous coal for a 600MW adopted the turbulent burner of prior art, the ignition oil amount was 200kg/h to flame stabilization, and adopts burner of the present invention, the ignition oil amount only is 60kg/h, and igniting is stable).Three, after coal dust of sending here from wind pulverized coal feed pipe and air flow into concentrated ring in the air channel, form higher coal powder density in the central area in an air channel, when entering the one-level combustion chamber, breeze airflow will form low regime, the coal powder density of low regime is very high, the required ignition heat of coal dust reduces, help coal dust and light, surely fire effective.Four, main oil gun is lighted in thermal-flame that the back forms and the one-level combustion chamber low speed coal dust and is directly contacted the characteristic of pulverized coal particle is changed, the high rate of heat addition is accelerated the fugitive constituent speed of separating out greatly, the sharply rising of pulverized coal particle temperature, explosion, pulverizing and violent burning, coal dust firing will be very abundant like this, and the flame of generation is highly stable.
Description of drawings
Fig. 1 is that overall structure master of the present invention looks cutaway view, and Fig. 2 is the A-A cutaway view of Fig. 1, and Fig. 3 is that the B of Fig. 1 is to view.
The specific embodiment
The specific embodiment one: in conjunction with Fig. 1~3 explanation present embodiments, present embodiment comprises air channel 1, concentrated ring 2, one-level combustion chamber 3, secondary combustion chamber 4, interior cyclone 5, interior secondary wind air channel 6, outer secondary wind air channel 8, nozzles 10, the 3rd wind channel tube 11, second wind channel tube 12, first wind channel tube 14 and main oil gun 17 one time; Described burner also comprises outer cyclone 7, three grades of combustion chambers 9, second gripper shoe 13, first gripper shoe 15 and sleeve pipes 19; Be an air channel 1 in described first wind channel tube 14, the port of export of first wind channel tube 14 is fixed with nozzles 10, concentrating ring 2 is fixed in first wind channel tube 14, and the diameter that concentrates ring 2 concentrates ring 2 directions towards nozzles 10 along this and reduces gradually, the front end of described sleeve pipe 19 is an openend, the rear end of sleeve pipe 19 is a blind end, the front end of sleeve pipe 19 passes first wind channel tube 14 and is packed in the concentrated ring 2, described one-level combustion chamber 3 is fixed in first wind channel tube 14 of sleeve pipe 19 front ends by first gripper shoe 15, described secondary combustion chamber 4 is fixed in first wind channel tube 14 of one-level combustion chamber 3 front ends by second gripper shoe 13, be three grades of combustion chambers 9 in first wind channel tube 14 of secondary combustion chamber's 4 front ends, the rear end that one end of described main oil gun 17 passes sleeve pipe 19 is fixed in the sleeve pipe 19, the port of export of main oil gun 17 is corresponding with the arrival end of one-level combustion chamber 3, second wind channel tube 12 is solidly set on first wind channel tube 14 and is positioned at the front end of first wind channel tube 14, it between second wind channel tube 12 and first wind channel tube 14 interior secondary wind air channel 6, interior cyclone 5 is fixed in the interior secondary wind air channel 6, the 3rd wind channel tube 11 is solidly set on second wind channel tube 12 and is positioned at the front end of second wind channel tube 12, it between the 3rd wind channel tube 11 and second wind channel tube 12 outer secondary wind air channel 8, outer cyclone 7 is fixed in the outer secondary wind air channel 8, the axial distance of the mouth of pipe of sleeve pipe 19 front ends and one-level combustion chamber 3 inlets is b, the front end of sleeve pipe 19 produces the recirculating zone, the preceding border of described recirculating zone to the axial distance of the mouth of pipe of sleeve pipe 19 front ends is a, axial distance b between 3 inlets of the mouth of pipe of described sleeve pipe 19 front ends and one-level combustion chamber greater than preceding border, recirculating zone to the axial distance a between the mouth of pipe of sleeve pipe 19 front ends, the concentrated ring 2 of present embodiment is three grades and concentrates ring to have concentrated effect preferably to entering a coal dust and the air in the air channel 1.
The specific embodiment two: in conjunction with Fig. 1 present embodiment is described, the difference of the present embodiment and the specific embodiment one is: the burner of present embodiment also comprises auxiliary oil gun 18; The rear end that one end of described auxiliary oil gun 18 passes sleeve pipe 19 is fixed in the sleeve pipe 19 and with main oil gun 17 and be arranged in parallel, and the port of export of auxiliary oil gun 18 is corresponding with the arrival end of one-level combustion chamber 3.When flame instability, can in time enable auxiliary oil gun 18, help coal dust firing.
The specific embodiment three: in conjunction with Fig. 1 present embodiment is described, the difference of the present embodiment and the specific embodiment two is: the burner of present embodiment also comprises fire inspection pipe 16; The rear end that one end of described fire inspection pipe 16 passes sleeve pipe 19 is fixed in the sleeve pipe 19, and the port of export of fire inspection pipe 16 is corresponding with the arrival end of one-level combustion chamber 3.So be provided with, can detect main oil gun 17 igniting at any time after, flame holding when flame instability, can in time be enabled auxiliary oil gun 18 on every side, helps coal dust firing.
Operation principle is: after coal dust of sending here from wind pulverized coal feed pipe and air flow into concentrated ring 2 in the air channel 1, form higher coal powder density in the central area in an air channel 1, when entering one-level combustion chamber 3, breeze airflow will form low regime, thermal-flame and the one-level combustion chamber 3 interior low regime that form that main oil gun 17 is lighted back formation directly contact, coal dust firing will be very abundant like this, the flame that produces is highly stable, successively entering secondary combustion chamber 4 then contacts with pulverized coal particle and firing coal-dust with 9 backs, three grades of combustion chambers, realized the fractional combustion of coal dust, burning capacity is amplified step by step, spray into burner hearth through nozzles 10 at last, reaching a little fights quickens the purpose of coal dust firing, significantly reduces the required fire ignition energy of coal dust firing, has satisfied boiler and has opened, stop and the demand of low-load combustion-stabilizing.Secondary wind enters separated into two parts behind the burner by secondary air box, they are respectively through outer secondary wind air channel 8 and 6 air-supplies of interior secondary wind air channel, regulate the aperture of inside and outside cyclone, can change the ratio of inside and outside swirl secondary air, make the rotation of secondary wind by interior cyclone 5 and outer cyclone 7, form the recirculating zone, center in the central area of burner.Coal dust is concentrated and is sprayed into the center recirculating zone core of position over against burner, the coal dust amount of passing through the recirculating zone, center increases, and coal dust burns under the hypoxemia reducing atmosphere, prolongs the time of staying of coal dust, can control the generation of burning type NOx, also save a large amount of fuel oils simultaneously.