CN2092669U

CN2092669U - Burner for combustion of multiple coal

Info

Publication number: CN2092669U
Application number: CN 91200558
Authority: CN
Inventors: 谢毓麟; 胡仁德
Original assignee: PUHUA COAL COMBUSTION TECHNIQUE DEVELOPMENT CENTRE HARBIN
Current assignee: PUHUA COAL COMBUSTION TECHNIQUE DEVELOPMENT CENTRE HARBIN
Priority date: 1991-01-16
Filing date: 1991-01-16
Publication date: 1992-01-08

Abstract

The utility model discloses a coal dust burner of multiple coal kinds, which has the functions of firing reinforcement and burnout reinforcement. The utility model can also be applied to being used as a main burning device on a dwarf boiler of burning coal dust and a grate whose horsepower of single heating power is more than 1000KW, and the utility model can also be used on a power station boiler. The burner appliance has unique aerodynamic characteristics, has the function of both firing reinforcement and burnout reinforcement and has favorable low load characteristics. The utility model can burn coal kinds such as lignitic coal, various soft coals, lean coal, etcThe minimum thermal power of burning is low, which can reach 1000 kw (3600*10+[3]kj/h or 860*10+[3]kcal/h).

Description

Burner for combustion of multiple coal

What the utility model related to is coal burner.

Existing coal burner has spiral-flow type and single flow (to see boiler combustion equipment for two types, the P263 of Xi'an Communications University), its common feature is coal dust and all combustion air finally mixing in burner hearth, the morning or the evening of mixing are depended on coal, and different coals is then adapted to by multi-form burner and its corresponding air distribution parameter.Because being everlasting, steam coal changes in the certain limit; boiler load also changes within the specific limits in the actual motion; the variation of load must cause the variation of air distribution parameter; and burners in prior is low to the adaptive capacity of these variations, usually can reduce the reliability and the performance driving economy of burning therefrom.It is desired that the burner of seeking to adapt to many coals and have good underload characteristic is that boiler is put into practice.For this reason, usually adopt various measures to strengthen ignition process to existing burner and still can keep combustion stability when reducing to scheme to reach the ature of coal variation and load.The domestic combustion powder burner of flameholder " band " (patent No. CN85109436) that has developed, poor same direction jet technology (patent No. CN85100050) and sandwich-wind combustor (patent No. 86102940) and various coal dust give and fire the chamber and all belong to this type of at top speed.These measures all focus on strengthens its ignition process, can not strengthen the after-flame process simultaneously and improve the burning economy.

The purpose of this utility model provides and a kind ofly has good flammability and after-flame performance concurrently and good underload characteristic is arranged, and can adapt to the burner of many coals burnings.Its thermal power is low to moderate the low capacity coal burner of 1000KW.

In order to achieve the above object, the technical measures taked of the utility model are: realize that by burner structure a wind rotates; All secondary wind is also tangentially injected at a high speed with the classification of pencil form, recirculating zone and exteenal reflux district in forming respectively in spout.The temperature adjustment flue gas that refluxes to the recirculating zone makes coal dust obtain good ignition condition.Simultaneously, the disturbance ability that secondary wind is at a high speed had with whirlwind bundle air-flow is mixed coal dust strongly with air in spout, obtained good after-flame condition.Burner for various kinds of coal just has concurrently strengthens the function of catching fire and strengthening after-flame.

Below in conjunction with accompanying drawing and embodiment the present invention is further described.

Fig. 1 burner for various kinds of coal sketch.

Fig. 2 burner for various kinds of coal air flow stream field pattern.

Below each accompanying drawing is described further:

Burner shown in Figure 1 is by once distinguished and admirable road (1), the distinguished and admirable road of secondary (2) (3) (4) and spout (5) and igniter (6) are formed.The required whole air quantity of coal dust firing are divided into primary and secondary air and enter burner.Wherein primary air ratio changes in 10% to 30% scope according to load variations.A wind is to spray into burner cavity by helix spiral case eddy flow.Secondary wind is axially to divide three grades along burner to send into burner cavity with pencil, first order pencil secondary wind is also angled in the same way by distinguished and admirable road of secondary (3) and burner axis air-flow direction of advance by distinguished and admirable road of secondary (2) and second level pencil secondary wind, makes the air-flow that is sprayed onto inner chamber form the imaginary circle that varies in size.Third level pencil secondary wind by the distinguished and admirable road of secondary (4) its to spray into direction be the vertical imaginary circle that also forms with burner axis.At circumferencial direction, the first order and third level runner are axially side by side, and second level runner and their stagger arrangement.Spout (5) is the main part of burner cavity, is positive column type.The main process of coal dust firing tissue is finished in burner cavity.The igniting of coal dust is that the igniter (6) that two on mat tangentially is installed in gap between a wind outlet flow (1) and secondary air box (8) inwall is finished.Igniter flame is rotation ejection between the pipe in wind outer tube and secondary air box.In wind central tube, can insert combustion-supporting or mix burning with oil gun or air gun, and feed corresponding combustion air.

Figure 2 shows that burner air kinetic current field pattern, it has reflected the main process of tissue burning.From flow field figure as can be seen, the rotatablely moving an of wind produce little recirculating zone (12) in the exit and make coal dust in its exit just to burner cavity wall segregation, cause wall near coal powder density concentrated.In when igniting, it directly contacts with the igniter swirl flame and has possessed very favourable ignition condition.The classification of secondary wind pencil tangentially sprays into, and has formed complicated air velocity distribution.Form recirculating zone, center (10) in the centre and between spout inner end inwall and air flow stream, formed exteenal reflux district (11).The high-temperature flue gas that refluxes in inside and outside recirculating zone has been for coal dust provides the primary condition of catch fire thermal source and smooth combustion, makes burner in normal the no good performance of catching fire with smooth combustion that has under combustion-supporting.In view of primary and secondary air is all mixed at burner cavity, and because secondary wind has very high-speed, coal dust and whole combustion air little space in spout under high disturbance obtain high-intensity mixing, for after-flame provides utmost point advantageous conditions, make into the excess air coefficient of stove and can reduce to 1.05～1.17 and do not reduce the burning economy.Above-mentioned stream condition makes burner can strengthen ignition process can strengthen the after-flame process again.The measure that burner adopted not only makes burner have very high burning reliability and economy by its unique stream condition of its implementation, has good underload characteristic, can also be adapted to the burning of many coals.The fuel combination of bituminous coal, brown coal, bituminous coal and anthracite and petroleum coke and bituminous coal for example, its burn-off rate can reach 95～99%, and the thermal power of burner can be hanged down and be reached 1000KW.

For the high temperature of the flue gas that keeps refluxing, according to coal, wall with refractory lining, refracto is in various degree laid in the exit of burner.

Because coal dust firing is in spout, burner cavity and secondary wind nozzle at different levels must be made with high-temperature alloy steel.The spout liner should apply exotic material.

Embodiment

Use above-mentioned technical measures, transform as at a chain of stations bar oven on the boiler of coal-powder boiler and obtained enforcement, the burner heat input rate that is adopted is 2000KW.

Burner parameter of (i.e. 100% load) under rated power is:

Primary air ratio is 10%, and wind-warm syndrome is 32 ℃; Secondary wind rate is 90%, and wind-warm syndrome is 70 ℃.

With liquefied gas as the igniting thermal source.

Burner once burnt coal with brown coal, bituminous coal, anthracite and bituminous coal mixed coal and petroleum coke and bituminous coal mixed coal as examination.Burner has stood test under different load.Result of the test is listed in the table below:

Claims

1, a kind of multi-coal combustion method, it is characterized in that spraying into burner cavity (9) by the helix spiral case with rotary movement with a wind of coal dust, coal powder density is concentrated near causing inner chamber (9) wall, igniter (6) thus the swirl flame of ejection directly contacts the ignition condition that provides extremely beneficial with high concentration pulverized coal, secondary wind divides three grades to spray into burner cavity with pencil along burner axis air-flow direction of advance, first order pencil secondary wind in described three grades is also angled in the same way by distinguished and admirable road of secondary (3) and burner axis air-flow direction of advance by distinguished and admirable road of secondary (2) and second level pencil secondary wind, make the air-flow that is sprayed onto inner chamber form the imaginary circle that varies in size, third level pencil secondary wind is vertical with burner axis and also form an imaginary circle by its emission direction of the distinguished and admirable road of secondary (4), said flow has formed complicated air velocity distribution in inner chamber, the centre has formed recirculating zone, center (10), and between the inwall of inner chamber and air flow stream, form exteenal reflux district (11), the high-temperature flue gas that refluxes in inside and outside recirculating zone provides primary condition for catching fire and surely firing of coal dust, because all pencil secondary air separating levels are injected with tangential manner and are had very high speed and a strength of turbulence, making coal dust and whole combustion air obtain high strength in the little space of inner chamber mixes, thereby the optimum condition of after-flame is provided, has made into coefficient of excess in the stove and be reduced to 1.05～1.17.

2,, it is characterized in that wherein primary air ratio accounts for 10～30% of total wind rate according to the described combustion method of claim 1.

3, according to the described combustion method of claim 1, it is characterized in that it can adapt to the burning of multiple coal, for example: the fuel combination of bituminous coal, anthracite, brown coal, bituminous coal and anthracite and petroleum coke and bituminous coal, its burn-off rate can reach 95.78～99.09%, and thermal power can be hanged down and be reached 1000KW.

4, a kind of for finishing the burner of the described combustion method of claim 1, mainly comprise once distinguished and admirable road, secondary air box, the distinguished and admirable road of secondary, combustion-supporting rifle, burner nozzle etc., it is characterized in that a wind shell is conventional spiral case eddy flow shape, combustion-supporting rifle (7) can be arranged in the central tube of a wind outlet flow (1), the outside coaxial with a wind outlet flow (1) is with secondary air box (8), two burning torches (6) equidistantly tangentially are installed in gap between a wind outlet flow (1) and secondary air box (8) inwall along circumference, the leading portion of secondary air box inwall is cylindrical, the tapered expansion body of back segment, the forward part of formation burner cavity.The end of bullet expansion connects with the spout (5) that constitutes the burner cavity rear section, termination and coaxial before and after both, and inner chamber spout (5) is cylindrical.The inwall of described secondary air box along the air-flow direction of advance at a distance of and draw respectively with the axis distinguished and admirable road of angled first order secondary (2) and the distinguished and admirable road of second level secondary (3) with and export the distinguished and admirable road of third level secondary (4) of vertical axis, be axially side by side in the circumferencial direction first order and the distinguished and admirable road outlet of third level secondary, and the distinguished and admirable road outlet of the second level and third level secondary is stagger arrangement.

5,, it is characterized in that the combustion-supporting rifle that inserts in once distinguished and admirable road (1) central tube can be oil combustion gun or gas gun according to the described combustion method of claim 4.

6,, it is characterized in that the interior wall liner of spout (5) becomes the adiabatic section of inner chamber with anti-thermal control material according to the described combustion method of claim 4.