CN86207418U - Coal-powder direct ignition burner - Google Patents

Abstract

The utility model discloses a burner for corner firing pulverized coal boiler in the thermal power plant to ignite and support combustion. The utility model can be transformed by the primary air jet tube of the existing burner. The inner of the utility model is provided with a burner tube and an igniting gun, and the igniting gun can ignite the primary air (the mixture of the air and the powdered coal) streaming through the burner tube. The primary air streaming through the burner tube is used for cooling and burning with flame jetted from the burner tube at the outlet of the utility model. The utility model ignites and supports combustion mainly by the combustion of the powdered coal and can save large numbers of igniting fuel. When the igniting gun is shut, the utility model can be used as a primary air jet tube and still holds characteristics of the burner.

Description

Coal-powder direct ignition burner

The utility model relates to coal burner, is a kind of burner for large-scale corner firing pulverized coal boiler ignition of thermal power plant and combustion-supporting usefulness.

Mostly the igniting of existing thermal power plant large coal powder boiler and combustion-supporting is to install large-scale oil gun or special-purpose oil burner is set in the overfiren air port of coal burner complete oil firing in the ignition of the boiler starting process.200,000 kilowatts of units of a confession, evaporation capacity be 670 tons/time boiler, each ignition oil is up to more than 50 tons.The igniting of whole nation thermal power plant pulverized-coal fired boiler and combustion-supporting considerable with oil mass.Moreover China is many with light diesel fuel supply power plant, and this is a kind of serious high-rank fuel waste.

Domestic some power plant in recent years adopts coal dust pre-combustion chamber burner to carry out ignition of the boiler, mainly is to have obtained oil-saving effect on some are equipped with the boiler of " Muffle furnace " originally.But the precombustion chamber volume is big, it is little to exert oneself, the easy coking that is in operation, but also changed original burner characteristic, particularly for large-scale corner-fired boiler, because its volume is difficult to employing too greatly.

Abroad from late nineteen eighties, carried out some research work to saving ignition of the boiler with oil, what wherein be used for corner-fired boiler is the described coal dust direct ignition system of No. 4241673 patent of the U.S. " Direct of ignition of pulverized coal ".This system must special-purpose igniting pulverized coal preparation system and the burner of installing.And need with high-quality bituminous coal and the defeated powder system of device high concentration.This ignition system complexity is invested very greatly, still is in the trial period abroad.

The purpose of this utility model, be to provide a kind of coal dust direct-fire burner that is applicable to general corner-fired boiler and general coal, this burner can mainly be lighted a fire with coal dust firing or be combustion-supporting, to reduce the consumption of igniter fuel, and after finishing, igniting, do not change the characteristic of original burner still as the ordinary burner operation.

This start-up burner is achieved in that the front portion installing combustion tube (7) in a wind jet pipe of original corner firing coal powder boiler straight-flow type burner (being the pipeline section that coal dust-air mixture enters burner hearth), make wind of a part enter combustion tube, and the once distinguished and admirable circular passage that is constituted between a combustion tube and the wind jet pipe (6) of crossing of remainder; At insertion point, combustion tube rear portion firelock (11).When ignition of the boiler or need when combustion-supporting, by general mode commonly used, catch fire as the fuel (for example oil) that makes the burning torch ejection with electric spark, at this moment light the coal dust in the wind one time with a wind facies chance that enters combustion tube, and a wind of the combustion tube outside of flowing through plays a part the cooling combustion pipe, and, spray into burner hearth together in wind outside nozzle and flame mixed combustion from the combustion tube ejection, so just realized with the combusting coal fines being the main ignition of the boiler or combustion-supporting of carrying out.Because the coal powder density in the combustion tube is higher, thereby flame propagation speed, so the needed heat ratio of firing coal-dust is generally much smaller at the heat that burner hearth overfiren air port firing coal-dust needs in combustion tube, so can save the consumption of igniter fuel.When closing burning torch, the then coal dust burn-out in the combustion tube, start-up burner only rose and sprayed a wind action this moment, so do not change the characteristic of original burner.

Burning torch can be with oil gun or gas ignition rifle, and under normal conditions, thermal power plant mostly has fuel system, so adopt oil gun more convenient.

In order to make burning torch in combustion tube, change the position, to obtain the best combustion effect, also for the ease of safeguarding and cleaning, be provided with the seal receptacle (10) of tep reel root at the elbow part of a wind jet pipe simultaneously, burning torch inserts in seal receptacle, and can move axially front and back.

The transverse shape of a combustion tube and a wind jet pipe (start-up burner shell just) preferably adopts circle, can make air-flow even like this, and thermal deformation is little.

Be welded with vertical fin (8) in the anterior appearance of combustion tube,, reduce its tube wall operating temperature, combustion tube can be made of ordinary carbon steel to strengthen the cooling effect of wind to combustion tube.

The utility model can change following factor and adapt to different coals:

1, the ratio of combustion tube basal area and its outside cooling duct area.

2, the distance (length of promptly lighting a fire) of burning torch indentation combustion tube outlet.

3, burning torch exerts oneself.

For bituminous coal, owing to catch fire easily and flame propagation speed, required igniting heat is very little, can adopt the very little burning torch of exerting oneself.Can adopt simultaneously less combustion tube diameter and short igniting length, be heated and increase cooling with minimizing.

For the meager coal or the anthracite of difficult to burn more, remove and adopt bigger combustion tube diameter (but can not make the gap of cooling duct too little, in order to avoid cause coal dust to stop up) and than beyond the long igniting length, the method that available in principle increasing burning torch is exerted oneself overcomes the coal powder ignition difficulty.Because when the increasing burning torch was exerted oneself, igniter fuel and coal dust be burning together in combustion tube, its result is equivalent to increase volatile matter content in the coal dust, will significantly improve the fire behaviour of coal dust.

Should be noted that, fineness of pulverized coal is very big to the influence of needed igniting heat and flame propagation velocity, no matter any coal all should make full use of this efficiency factor, as much as possible for igniting grinds fine breeze, so that save the after-flame degree of coal dust in igniter fuel and the raising ignition process to greatest extent.

Major advantage of the present utility model is:

1, compare with present conventional igniter, can save igniting and combustion-supporting fuel significantly, its saving rate is different with the equipment situation because of ature of coal, fineness of pulverized coal, generally can save more than 70%.

2, adaptability is strong, can be used for general corner firing pulverized-coal fired boiler and general coal, and both has been applicable to the transformation of operational outfit, also is applicable to the employing of new equipment.

3, compare with pre-combustion chamber burner, this start-up burner volume is little, exert oneself big, do not have coking problem, and it is short to transform the duration, and maintenance work is few.

4, do not change the characteristic of original burner.

5, simple in structure, and do not need to change original pulverized coal preparation system and miscellaneous part, thereby retrofit work amount and improvement expenses are few.

Below in conjunction with description of drawings the utility model be used to burn embodiment of meager coal boiler:

Fig. 1 is the horizontal cross of start-up burner.

Wherein: the 1-wear strip; Oblique section of wind jet pipe of 2-; A wind jet pipe of 3-stage casing; The 4-flange; The 5-carriage; A wind jet pipe of 6-leading portion; The 7-combustion tube; The 8-fin; The 9-concentric reducer; The seal receptacle of 10-tep reel root; The 11-oil gun; 12-electric spark device.

Fig. 2 is Fig. 1's " A-A " cutaway view, the structure of expression wear strip.

Fig. 3 is Fig. 1's " B-B " cutaway view, the structure of expression carriage.

Fig. 4 is Fig. 1's " C-C " cutaway view, the structure of expression fin.

Fig. 5 is the oil gun schematic diagram.

Wherein: the 13-outer tube; The 14-inner sleeve; 15-core pipe; 16-oil nozzle; 17-surely fires awl.

Four wind jet pipes of lower floor of original burner are replaced by four direct-fire burners as shown in Figure 1, and its discharge area equates with former once wind nozzle exit area or is approaching, makes boiler keep original primary air velocity constant when normal operation.The gross capability of four start-up burners accounts for more than 25% of boiler total heat duties, to satisfy the needs of heat in the ignition of the boiler process.The design rating of each start-up burner be 3.5 tons/time, burner housing, just the leading portion (6) made by φ 377 * 10 common steel tubes of wind jet pipe, stage casing (3) and tiltedly section (2) constitute, wherein leading portion is connected with flange (4) with the stage casing, tiltedly section is welded into 160 ° of elbows with the stage casing section, so that the insertion of oil gun.One end of concentric reducer (9) and inclined tube welding, the other end are welded with an original airduct road when mounted.Combustion tube (7) is made of φ 299 * 10 common steel tubes, and length is 1000 millimeters, and about 30 millimeters of its port of export indentation burner nozzle is welded with (8) 18 of long by 500, wide by 27, thick 6 millimeters vertical fin in its forward outer surface.

The structure of oil gun (11) is the mechanical atomization type as shown in Figure 5, exert oneself be 125 kilograms/time, be arranged on the combustion tube center, about 900 millimeters of the distance (length of promptly lighting a fire) of its head and combustion tube outlet.Be welded with steady right awl (17) at the oil gun front end, it is shaped as taper shape, and diameter is 130 millimeters, and cone angle is 50 °, and its effect is the stability that increases oily flame.Constitute airtight thermal insulation layer between outer tube (13) and the inner sleeve (14), heated by a wind with lightening core pipe (15) and oily nozzle (16), and pass to the cooling air between inner sleeve and the core pipe, make core pipe and oily nozzle keep lower temperature, to eliminate the blocked phenomenon of oily nozzle.Core pipe and oily nozzle can be extracted out at any time in boiler operatiopn and check.

In the structural design of start-up burner, also considered to improve life-span of being ground parts and easy to maintenance as far as possible.The effect of wear strip (1) is to prevent the wearing and tearing of coal dust to oil gun outer tube and electric spark device (12) in the burner, also alleviates the coal dust of a wind when turning simultaneously and separates.The rear portion of oil gun and electric spark device is supported in the seal receptacle (10) of tep reel root, and the front portion is supported on the carriage (5), and carriage is welded in the rear end of combustion tube.Combustion tube can be repaired from burner hearth or be changed together with carriage, and the inside and outside sleeve pipe of oil gun also can be extracted repairing or replacing out together with the steady awl that fires from burner hearth, and the electric spark device can be extracted inspection at any time out from its sleeve pipe in boiler operatiopn.

Claims (6)

1, a kind of direct-fire burner that includes wind jet pipe, uses for the corner firing pulverized-coal fired boiler, it is characterized in that: at the front portion of a wind jet pipe (6) installing combustion tube (7), and make looping passage between combustion tube and the wind jet pipe, at insertion point, combustion tube rear portion firelock (11).

2, burner according to claim 1 is characterized in that burning torch is an oil gun.

3, burner according to claim 2 is characterized in that the head of oil gun is welded with steady combustion awl (17).

4, burner according to claim 2 is characterized in that the core pipe (15) of oil gun is contained in the bilayer sleeve, constitutes airtight thermal insulation layer between outer tube (13) and the inner sleeve (14), and passes to the cooling air between inner sleeve and the core pipe.

5, according to claim 1,2,3,4 described burners, the transverse shape that it is characterized in that a combustion tube and a wind jet pipe is for circular.

6, burner according to claim 5 is characterized in that the combustion tube forward outer surface is welded with vertical fin (8).

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