Figure 15 is that Figure 16 is its front elevation as the vertical section side view of burner one example of existing powdered fuel burner combusting coal fines.Among the figure, be expressed as respectively: 01 is the coal dust carrier pipe, and 02 is the coal dust gaseous mixture, and 03 is distributor, 04 is burner, 05 is coal pipe, and 06 is the rich mixture burner, and 07 is light mixture combustion device, 08 is auxiliary air, 09 is the burner secondary-air passage, and 10 is coal nozzle, and 11 is the auxiliary air nozzle.
Spray shouting device 04 is to be made of low light mixture combustion device 07 one of high rich mixture burner 06 of coal powder density and coal powder density.Rich mixture burner 06 and light mixture combustion device 07 then by the coal pipe 05 of its bottom center setting, be trapped among it around dihedral secondary-air passage 09, the dihedral coal nozzle 10 that is connected in its export department, auxiliary air nozzle 11 constitute.Pass through the coal dust 02 that coal dust carrier pipe 01 is carried together with an air, effect according to distributor 03, distribute respectively and infeed rich mixture burner 06 and light mixture combustion device 07, after spraying in the combustion chamber by coal pipe 05 and coal nozzle 10, mix, spread, burn with the auxiliary air that sprays by same auxiliary air nozzle 11.
The burner of above-mentioned firing coal dust is divided into high concentration gaseous mixture and low concentration gaseous mixture by distributor 03 with coal dust gaseous mixture 02, imports rich mixture burner 06 and light mixture combustion device 07 respectively, make its burning, therefore, can suppress the generation of NOX, make flameholding simultaneously.
Figure 17 be in the powdered fuel burner 1 air to the ratio and the flame propagation velocity graph of a relation of fuel.
Aforementioned existing combusting coal fines burner is divided into high concentration gaseous mixture (the A point of Figure 17) by distributor 03 with coal dust gaseous mixture 02 and sprays in the combustion chamber with low concentration gaseous mixture (the B point of Figure 17).As shown in the figure, under the situation of using coal, the high concentration gaseous mixture is near the condition of 1 air/fuel ratio of flame propagation velocity maximum usually, and flame can be stablized.But using under the situation of nonflammable fuel because the flame propagation velocity maximum is to be near 1.0 at 1 air/fuel ratio, even the high concentration gaseous mixture also difficulty satisfy this condition, it is unstable that flame often becomes.
In addition, coal dust gaseous mixture 02 is not owing to have through special rectification, and when it ejected by coal nozzle 10, it was inhomogeneous also usually to be that air mixes with coal dust, catches fire, the combustibility deterioration.
Moreover, bend in the burner noz(zle) causes the accumulation of coal dust at the viscous flow position with the viscous flow of most advanced and sophisticated wing coal dust gaseous mixture 02, particularly at the most advanced and sophisticated coal dust of piling up of burner noz(zle), be subjected in the combustion chamber intense radiation heat and catch fire, become the reason of burner noz(zle) scaling loss, and then make scaling loss expand the problem of whole burner in addition.
Purpose of the present invention promptly is to eliminate all problems that exist on the burner of existing combusting coal fines, to obtain stable burning, provides a kind of gratifying burner that can prevent the burner scaling loss.
The present invention promptly is a device in order to achieve the above object, powdered fuel burner provided here is characterized in that: the flame formation eddy current that circles round in the combustion chamber, a plurality of burner noz(zle)s are arranged at chamber wall, when the powdered fuel supply pipe is connected in this nozzle, the burning distributor that powdered fuel is separated into high concentration powder and low concentration powder is set between burner noz(zle) and powder feeding pipe, in respectively with high concentration powder and low concentration powder feeding previous combustion nozzle, set burner noz(zle) sprays to the inboard of aforementioned eddy current with the high concentration powder, and the low concentration powder is sprayed to the outside of eddy current.
The present invention is owing to have an above-mentioned formation, and the flame formation eddy current that circles round in the combustion chamber is provided with a plurality of burner noz(zle)s on the chamber wall, so that flame can be kept mutually is stable, obtains smooth combustion.
In addition, powdered fuel burner provided by the present invention also has the feature of the downward-sloping installation of burner noz(zle).
As according to the present invention, because the downward-sloping installation of burner noz(zle), can increase the stability of burning by the buoyancy of downward flame, can increase burning time thus at burner, therefore can increase caloradiance to burner, make burning more stable.
Moreover its feature of powdered fuel burner provided by the present invention also is: the burner noz(zle) and the burner noz(zle) along continuous straight runs setting that sprays into the low concentration powder that spray into the high concentration powder.
As according to the present invention, owing to will spray into the burner noz(zle) and the burner noz(zle) along continuous straight runs setting that sprays into the low concentration powder of high concentration powder, the whole height of burner can reduce, thereby the fired heat duty of burner part can increase, and might obtain more stable burning.
In addition, Powdered its feature of burning burner provided by the present invention also is: aforementioned fuel distributor is a whirlwind separator.
As according to the present invention, because by whirlwind separator powdered fuel is separated into high concentration powder and low concentration powder, separating property is improved, 1 air/fuel that might make the high concentration gaseous mixture is than near 1.0, thereby, even nonflammable fuel also can smooth combustion.
Besides, its feature of powdered fuel burner provided by the present invention also is: the necking section is set simultaneously on the burner noz(zle) that sprays into the high concentration powder, the rectifying block of fuel mixture being carried out rectification is set near this necking section.
The present invention has adopted the cyclone type distributor, guarantee the coal dust mixed gas separation is become high concentration gaseous mixture and low concentration gaseous mixture with its good separating property, accepting the 1st burner noz(zle) of high concentration gaseous mixture, the rotating force of cyclone separator causes remaining to the flowing of burner ejiction opening and uneven gaseous mixture, and prevents the deterioration that the coal powder density in burner ejiction opening part distributes with rectifying block.
This rectifying block is being provided with near near the cyclone separator, weakened the rotating force of cyclone separator again, make the cyclone separator decrease in efficiency, probably can not get coal powder density than higher gaseous mixture, on the other hand, that the ejection flow velocity is set is inhomogeneous and be subject to problem such as burner flame influence owing to be created in burner opening, so preferably rectifying block is arranged near the necking section of burner, distributes to obtain even flow.
The drawing simple declaration
Fig. 1-the present invention's the 1st example boiler side view,
The secondary-air passage of Fig. 2-Di 1 example burner constitutes oblique view,
Fig. 3-Di 1 example burner plane is provided with figure,
Fig. 4-Di 1 example combustion chamber internal combustion situation medelling figure,
Fig. 5-Di 1 example burner configuration horizontal sectional view,
Fig. 6-the present invention's the 2nd example burner side view,
The II-II sectional drawing of Fig. 7-Fig. 6, (a) and (b), (c), (d) correspond respectively to different embodiment,
The III-III sectional drawing of Fig. 8-Fig. 6, (a) and (b), (c), (d) correspond respectively to the different embodiment of Fig. 7,
Air velocity measure of spread position description figure in the example of Fig. 9-Fig. 6,
The air velocity distribution key diagram of the comparative example of Figure 10-relevant the invention process form,
Figure 11-the invention process form the 1st embodiment air velocity distribution key diagram
Figure 12-the invention process form the 2nd embodiment air velocity distribution key diagram
Figure 13-the invention process form the 3rd embodiment air velocity distribution key diagram
Figure 14-the invention process form the 4th embodiment air velocity distribution key diagram
Figure 15-conduct has the powdered fuel burner now, the routine vertical section side view of one of firing coal dust burner,
The front elevation of Figure 16-Figure 15,
The ratio of 1 air/coal and flame propagation velocity graph of a relation in Figure 17-powdered fuel burner.
Fig. 1 is the side view of the boiler of the present invention's the 1st example, Fig. 2 is the oblique view that the bellows of burner in this example of expression constitute, Fig. 3 is that above-mentioned example burner plane is provided with figure, Fig. 4 is that Fig. 5 represents the horizontal sectional view of the burner configuration of above-mentioned example with the stove internal combustion situation medelling figure of above-mentioned example.
At first, as shown in Figure 1, burner noz(zle) 2 dips down and tiltedly is installed on the furnace wall of boiler furnace 1, after therefrom Pen Chu gaseous mixture catches fire, forms the flame 3 of U font by buoyancy.
Secondly, as shown in Figure 2, the secondary-air passage of present embodiment constitutes burning additional air mouth (A) and ejection fuel port FD, FL, vertically overlapped; And the ejection fuel port is respectively high concentration and mixes gas port FD and be set up in parallel with low concentration mixing gas port FL along continuous straight runs.
In addition, as shown in Figure 3, in the present embodiment, the powder of high concentration sprays to the inboard in the flame whirlpool 4 of circling round; The low concentration powder sprays to the outside in above-mentioned flame whirlpool.Thereby shown in the image pattern 4 like that, formed stable high density combustion zone at the combustion chamber central part.
The structure of the burner of present embodiment as shown in Figure 5, the powdered fuel of being carried by primary air is separated into rich mixture by cyclone separator 7 and light gaseous mixture is spraying fire burns in the combustion chamber.
Bottom borrows Fig. 6 that the present invention's the 2nd example is described.
On Fig. 6, the 02nd, the coal dust gaseous mixture, the 13rd, whirlwind shape distributor, the 14th, the high concentration rich mixture, the 15th, the low concentration gaseous mixture, the 16th, the 1st burner of rich mixture 14 usefulness, the 17th, the 2nd burner of low concentration gaseous mixture 15 usefulness, the 18th, the 1st burner noz(zle) of rich mixture 14 usefulness, the 19th, the 2nd burner noz(zle) of low concentration gaseous mixture 15 usefulness, the 20th, the upstream side rectifying block, the 21st, the downstream rectifying block, 25 is in the pipe of the 1st burner 16, the 28th, the length of upstream side rectifying block 20, the 29th, the length of downstream rectifying block 21, the 30th, burner necking section, the 31st, the inner core of guiding low concentration gaseous mixture.
Constituting like this in the present embodiment at each position, pressing the generation of the direction shown in arrow rotating force among the figure by cyclone type distributor 13, be separated into the rich mixture 14 and the low concentration gaseous mixture 15 of high concentration by the coal dust gaseous mixture 02 of 1 air conveying.High concentration rich mixture 14 sprays in the stove by the 1st burner 16 of rich mixture 14 usefulness; 15 the 2nd burners 17 by low concentration gaseous mixture 15 usefulness of low concentration gaseous mixture spray in the stove, come like this to spray into respectively, catch fire, burn.
The fuel apportionment ratio adapts to the performance of cyclone separator and adjusts, but here, rich mixture 14 1 sides of high concentration are about 90%.Fuel apportionment ratio (fuel quantity in the fuel quantity in the high concentration rich mixture 14/coal dust gaseous mixture 02) is that the ratio of 90%, 1 air/coal is about 1.0, the flame stabilization of nonflammable fuel.High concentration rich mixture 14 in the 1st burner 16 of rich mixture 14 usefulness gives rotating force by cyclone type distributor 13.
Circle round the high concentration rich mixture 14 that produces by near rectifying block 20,21 rectifications that are provided with the burner necking section 30, its air velocity be distributed in the 1st burner noz(zle) 18 the outlet section three places, upper, middle and lower about equally.Describe in detail by the embodiment back about this point.
On the other hand, at the 2nd burner noz(zle) 19 places of low concentration gaseous mixture 15 usefulness, even the 2nd burner 17 1 sides are not established rectifying block, also almost do not have and circle round mobilely, air velocity becomes evenly to distribute haply.
Like this, as according to present embodiment, the 2nd burner much less, do not remain in a standstill even do not exist in the burner at the 1st mobile burner 16 that circles round of worrying remaining cyclone separator yet, the coal dust gaseous mixture will evenly spray from the 1st, the 2nd nozzle 18,19, therefore coal dust can not piled up halfway with in the nozzle, thereby needn't worry the scaling loss of nozzle etc. yet.
To aforementioned so stable jet flow that can obtain in the 1st burner noz(zle) 18, with situation that rectifying block 20,21 is not set as a comparative example, and will be provided with rectifying block 20,21 as embodiment, borrow Fig. 7~14 to be illustrated.
And wherein, Fig. 9 has represented the air velocity distribution detection position as the 1st burner 18 export departments on following explanation basis.That is 22,23, the 24 velocity flow profile detection positions of having represented pipe top, pipe central authorities, pipe bottom respectively among Fig. 9.And here the internal diameter of the 1st burner noz(zle) 18 (the 2nd burner noz(zle) 19 is also identical) is 112mm.
(comparative example)
Figure 10 is that the air velocity under rectifying block 20,21 situation about not being provided with distributes, with it as a comparative example.
The air velocity of the 1st burner noz(zle) 18 ejection of using from rich mixture, it is slow to manage central 23 places, and pipe top 22, pipe 24 places, bottom are fast.The pipe bottom, presents uneven air velocity and distributes more than 3 times than the central fast mistake of pipe; And though not expression on the figure, fuel distribution also presents and the same tendency of air velocity distribution.
(embodiment 1)
By Fig. 7 a, Fig. 8 a, with Figure 11 embodiment 1 is described.And Fig. 7 a is the II-II section of Fig. 6, and Fig. 8 a is the III-III section of Fig. 6, and about this point, for Fig. 7 b~d, Fig. 8 b~d also is common in following other represented embodiment entirely.
In embodiment 1, the rectifying block 20 of upstream side becomes 90 ° of spacings, 4 row to be arranged on the wall of pipe interior 25 with upper and lower, left and right, and the rectifying block 21 in downstream also becomes same setting of upper and lower, left and right 4 row.In the present embodiment, the width 26 of rectifying block 20,21 is 4.5mm, and height 27 is 15mm, and length then is that upstream side rectifying block 20 is 100mm, and downstream rectifying block 21 is 120mm.And it is wide, high among other embodiment that address in the back, length also is same size entirely.
In the present embodiment with rectifying block 20,21 such assortments, detected air velocity distribution table is shown among Figure 11.
The flow velocity of pipe bottom 24 is the fastest, secondly is pipe central portion 23, and pipe 22 places, top are the slowest.Compare with the aforementioned comparative example of no rectifying block, the highest and difference lowest speed has diminished, and uniformity coefficient increases.
(embodiment 2)
By Fig. 7 b, Fig. 8 b and Figure 12 embodiment 2 is described.
Upstream side rectifying block 20 is identical with previous embodiment 1, and upper and lower, left and right become 90 ° of spacings, 4 row to be provided with; The rectifying block 21 in downstream has then moved 30 ° or 90 ° of spacing 4 row settings than embodiment 1 with the installation site respectively.Upstream side rectifying block 20 is all made meander configuration with downstream rectifying block 21.
Detected next air velocity distributes and is shown on Figure 12 in the present embodiment that rectifying block 20,21 is provided with like this.
The slowest at the central 23 place's flow velocitys of pipe, and pipe bottom 24 accelerates equally with pipe top 22 place's flow velocitys.Compare with previous embodiment 1, the highest and minimum speed difference has diminished, and the uniformity is improved.
(embodiment 3)
By Fig. 7 c, Fig. 8 c and Figure 13 embodiment 3 is described.
The rectifying block 20 of upstream side uniformly-spaced 6 is listed as setting by horizontal level by 60 ° of spacings; And downstream rectifying block 21 is identical with aforementioned embodiment 1, becomes the 90 ° of spacings in upper and lower, left and right, 4 row to be provided with.Left and right upstream side rectifying block 20 is same height with upstream side rectifying block 21, and the upper and lower meander configuration that becomes.
Detected air velocity distributes and is shown in Figure 13 in the present embodiment that rectifying block 20,21 is provided with like this.
As can be seen from Figure 13, its flow velocity is in pipe central authorities 23 and manage top 22 everywhere in same level, and accelerates at pipe 24 places, bottom.Compare with previous embodiment 2, pipe bottom 24 place's flow velocitys accelerate, and there is speed difference in pipe central authorities hardly with pipe top, so uniformity coefficient is able to further raising.
(embodiment 4)
By Fig. 7 d, Fig. 8 d embodiment 4 is described.
Upstream side rectifying block 20 is identical with aforementioned embodiment 3, is provided with by 60 ° of spacings, 6 row; And downstream rectifying block 21 becomes 6 row to be provided with the upstream side rectifying block equally.
The air velocity that detects in the present embodiment that rectifying block 20,21 is provided with like this distributes and is shown on Figure 14.
As can be seen from Figure 14, flow velocity is on pipe top 22 and manage bottom 24 everywhere in same level, and central 23 places are higher than pipe, but almost are in same level on 3 points.Be the most even person of flow velocity among aforementioned each embodiment.
Can know for the explanation of embodiment and with the contrast of comparative example that from above owing to be provided with rectifying block 20,21 near the necking section 30 of the 1st nozzle 18, the homogenising that flows in the pipe can obtain steady flow.
And in aforementioned each embodiment, the ratio of 1 air/coal is about 1.0, and the fuel apportionment ratio is 80% in embodiment 3, and is low slightly; And be about 90% in other embodiments.
In the present invention, the burning interior flame formation eddy current that circles round, and a plurality of burner noz(zle)s are being set on chamber wall, the powdered fuel supply pipe is being connected in the middle of this burner noz(zle), in between burner noz(zle) and powdered fuel supply pipe, be provided with fuel distributor, isolate high concentration powder and low concentration powder, in various powder feeding previous combustion nozzles, the high concentration powder is invested the inboard of eddy current; And the outside that the low concentration powder is invested eddy current, because burner noz(zle) is set like this, even use under the situation of nonflammable fuel, also can stable ignition, combustibility is improved.Especially, the oxidation environment of air abundance is arranged near sidewall of combustion chamber, can prevent the reduction corrosion of chamber wall pipe and the mineral matter in the fuel adhering to, piling up on the chamber wall.
In addition, in the present invention, make whirlwind shape owing to will be connected in the distributor of burner noz(zle), can isolate high concentration gaseous mixture and low concentration gaseous mixture, high concentration gaseous mixture and low concentration gaseous mixture can be separated ejection, even nonflammable fuel also can stable ignition (ratio of 1 air/coal be 1.0 near), combustibility is improved.
Moreover owing to be provided with rectifying block in high concentration burner one side, being distributed by the air velocity of burner noz(zle) ejection becomes evenly, can make to catch fire stablely, and flame holding is good.
Also have,, do not have the viscous flow of gaseous mixture, can prevent the fuel accumulation, prevent the scaling loss of burner because air velocity distributes and fuel distribution is even.