CN215174988U

CN215174988U - Top coal slime granulation air distribution burner of CFB boiler

Info

Publication number: CN215174988U
Application number: CN202120117087.6U
Authority: CN
Inventors: 李仁�; 彭红文; 殷艳霞; 白杰; 刘全壮
Original assignee: North China Power Engineering Co Ltd of China Power Engineering Consulting Group
Current assignee: North China Power Engineering Co Ltd of China Power Engineering Consulting Group; North China Power Engineering Beijing Co Ltd
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2021-12-14
Anticipated expiration: 2031-01-15

Abstract

The utility model relates to a CFB boiler top coal slime granulation air distribution burner, insert and locate furnace roof water-cooling wall, the burner contains the inside and outside concentric center taper pipe that cup joints in order, central tuber pipe, coal slime sleeve pipe and circumference wind sleeve pipe, coal slime sleeve pipe inner wall and central tuber pipe outer wall form the first ring chamber, its top is sealed, the annular of bottom lays the cutting block, coal slime sleeve pipe upper portion is connected with the coal slime access pipe that communicates with the first ring chamber, circumference wind sleeve pipe inner wall and coal slime sleeve pipe outer wall form the second ring chamber, its top is sealed, the annular of second ring chamber lays first stopper, be connected with the circumference wind access pipe that communicates with the second ring chamber on circumference wind sleeve pipe upper portion, second stopper and third stopper are laid to center taper pipe outer wall annular, the utility model discloses simple structure, the form coal slime is pressed into the sliver and falls from the whereabouts, the whole week receives the furnace roof is cracked and is heated and releases the volatile in the whereabouts process, the volatile components and carbon granules meet with the air inside and outside and are directly mixed and burnt, which is beneficial to reducing the loss of boilers q3 and q 4.

Description

Top coal slime granulation air distribution burner of CFB boiler

Technical Field

The utility model belongs to the power engineering field for the flying dust carbon content height problem that exists when solving CFB boiler top and mixing and burning the coal slime.

Background

The CFB boiler has the advantages of large heat storage capacity in the hearth, strong heat and mass exchange capacity, in-furnace desulfurization and low NO_XThe environment-friendly property of the emission has the advantage of being capable of directly and stably burning high-ash and high-water fuel.

The coal slime is burnt in the CFB boiler and is put into the boiler in two ways: one method is that the coal slurry is premixed in a coal yard and is delivered to a power plant through a coal conveying belt, if the coal slurry is not dried, the coal slurry is directly delivered to a boiler through the coal conveying belt for mixed combustion, the mixed combustion proportion generally cannot exceed 5 percent, otherwise, a coal conveying system is blocked, and the boiler cannot operate.

Alternatively, the coal slurry is fed separately to the boiler. The existing coal slime charging point is usually arranged at the top, the middle part (7-9 m away from the air distribution plate) and the lower part (1-2 m away from the air distribution plate), and the lower part comprises a material returning leg.

The lumpy coal slime entering a hearth through the top or the middle part of the hearth falls under the action of gravity and is heated by the convection of high temperature and rising flue gas of the hearth, surface moisture is evaporated in advance, a shell is hardened, after the coal slime is further heated, the moisture in the coal slime lump is evaporated and vaporized rapidly, the shell is smashed to form a plurality of small lumps, and then the small lumps are crusted and thermally exploded again until the small lumps become monomer particles and start to burn.

The middle feed fragmentation is superior to the top feed approach because it increases the combustion path of the fine coal.

The coal slurry spray gun is arranged at the bottom of the hearth, coal particles stay in the furnace for the first time, and fine coal particles which are difficult to capture by the separator are fully combusted, so that the carbon content of ash can be reduced, the comprehensive utilization of the ash is facilitated, the energy consumption of compressed air is increased, the requirement on coal slurry pretreatment for removing impurities is high, and the spray gun is easy to wear; the coal slime agglomerate fed by the return leg is directly mixed with hot ash, and preheating and drying are started before the coal slime agglomerate enters a hearth, so that the first residence time of coal particles is longest, the combustion efficiency is highest, but because the circulating ash amount is limited, when the ratio of the coal slime to the circulating ash does not meet the requirement, the coal slime is bonded in the return leg, and the high-ratio combustion of the coal slime is limited.

Compared with conventional particles, the coal slime lump is difficult to fluidize due to the weight, when the coal slime is put into a boiler in a lump mode, if the selection of a point of putting into the boiler is not proper and the diameter of the coal slime lump is too large, the thermal explosion is insufficient, bed fluidization dead zone and coking are caused when the lump falls into the bottom, and the boiler is forced to stop operation; and after the coal slime lump is crushed and reduced into coal particles, the particle size is far smaller than that of particles selected by conventional design, so that the coal slime lump is easy to elutriate and post-combust, and the elutriated fine particles are the reason for causing high carbon content of fly ash.

SUMMERY OF THE UTILITY MODEL

The technical problem solved by the utility model is to provide a CFB boiler put top coal slime granulation air distribution burner promptly.

The technical means adopted by the utility model are as follows.

A CFB boiler top coal slime granulation air distribution burner is inserted into a water cooling wall at the top of a CFB boiler and comprises a central taper pipe, a central air pipe, a coal slime sleeve and a peripheral air sleeve which are sequentially and concentrically sleeved inside and outside; the inner wall of the coal slime casing pipe and the outer wall of the central air pipe form a first annular cavity, the top of the first annular cavity is sealed, a plurality of partition blocks are annularly distributed at the bottom of the first annular cavity, a forming channel is formed between every two adjacent partition blocks, and the upper part of the coal slime casing pipe is connected with a coal slime access pipe communicated with the first annular cavity; the inner wall of the peripheral air sleeve and the outer wall of the coal slime sleeve form a second annular cavity, the top of the second annular cavity is sealed, a plurality of first limiting blocks are annularly distributed in the second annular cavity, a peripheral air channel is formed between every two adjacent first limiting blocks, and the upper part of the peripheral air sleeve is connected with a peripheral air access pipe communicated with the second annular cavity; the central taper pipe comprises a reducing section and an equal-diameter section, the section diameter of the reducing section is gradually increased along with the air inlet direction, the maximum diameter position is connected with the equal-diameter section, a third annular cavity is formed between the outer wall of the reducing section and the inner wall of the central air pipe, and a plurality of second limiting blocks and a plurality of third limiting blocks are annularly arranged in the third annular cavity.

Preferably, first ring chamber top is sealed through first sealed crown plate, second ring chamber top is sealed through second sealed crown plate, the sheathed tube top of perimeter wind is less than the top of central tuber pipe, the coal slime inserts the pipe and is located the sheathed tube second of perimeter wind and seals crown plate top.

Preferably, the coal slime access pipe and the peripheral wind access pipe are located above the furnace top water-cooled wall.

Preferably, the number of the first limiting block, the second limiting block and the third limiting block is not less than 3.

Preferably, the central taper pipe is arranged in a hollow mode.

Preferably, the outer wall of the perimeter air sleeve is fully welded with the furnace top water wall in a sealing mode, the partition block is fully welded with the central air pipe and the coal slime sleeve, the third limiting block is fully welded with the central air pipe and the central taper pipe, and the second limiting block is fully welded with the central air pipe.

Preferably, the top of the dividing block is wedge-shaped.

Preferably, a furnace top on-site suction fan is used for supplying air to the combustor, an air supply pipeline at the outlet of the furnace top on-site suction fan is divided into 2 branches which are respectively connected with the central air pipe and the peripheral air access pipe, and a standby secondary cold air pipeline is further connected to the air supply pipeline.

The utility model discloses produced beneficial effect as follows.

The utility model discloses simple structure, the form coal slime that will stick together is pressed into the sliver whereabouts in the exit, can effectively utilize rich pressure and the gravity of coal slime, the mud strip receives furnace heat radiation, the hot gas flow heating of central wind and perimeter wind is cracked very fast and release the volatile matter all around falling the in-process under, volatile matter and carbon granule meet the direct blending combustion with inside and outside air, can make the combustible gas and the small granule once only burn out that the separator can't catch, be favorable to reducing boiler q3, q4 loss. The mud is agglomerated into strips and falls, so that the problems of bed fluidization dead zone, coking and boiler shutdown caused by insufficient thermal explosion of the mud mass falling into the bottom of the hearth are thoroughly solved.

The upper part of the hearth belongs to a smoke diversion area, cold air entering the hearth downwards is expanded by heating and has superior quality transfer conditions with the diverted smoke, combustible materials flowing along with the smoke are favorably contacted with oxygen to be fully combusted, and extra anti-abrasion measures for a heated surface are not required.

Drawings

FIG. 1 is a schematic structural view of the top coal slime granulation air distribution burner of the CFB boiler of the present invention.

FIG. 2 is a schematic view of the air supply mode of the CFB boiler top coal slurry granulation air distribution burner of the present invention.

Detailed Description

As shown in figures 1-2, the utility model provides a CFB boiler puts a coal slime granulation air distribution burner inserts and locates CFB boiler furnace roof water-cooling wall, contains inside and outside concentric central taper pipe 3, central tuber pipe 1, coal slime sleeve pipe 2 that cup joint in order and perimeter wind sleeve pipe 4.

The inner wall of the coal slime casing pipe 2 and the outer wall of the central air pipe 1 form a first annular cavity 12, the top of the first annular cavity 12 is provided with a first sealing annular plate 7 to seal the first annular cavity, the bottom of the first annular cavity 12 is annularly provided with a plurality of partition blocks 11, a forming channel (not shown in the figure) is formed between the adjacent partition blocks 11, the top of each partition block 11 is in a wedge shape, the retention of the coal slime on each partition block 11 is reduced, the partition blocks 11 enter the forming channel as much as possible, and the partition blocks 11 are fully welded with the central air pipe 1 and the coal slime casing pipe 2. The upper part of the coal slime casing pipe 2 is connected with a coal slime access pipe 5 communicated with the first annular cavity 12.

4 inner walls of perimeter wind sleeve pipe and 2 outer walls of coal slime sleeve pipe form

second ring chamber

13, 13 tops in second ring chamber set up the sealed crown plate of second 8 and seal it, the first stopper 16 of a plurality of is laid to suitable position ring-type in the second ring chamber 13, can set up in second ring chamber 13 with different distribution mode according to the sheathed tube specification of reality, the embodiment shown in figure 1, position that flushes with furnace roof water-cooling wall sets up the first stopper 16 of round promptly, 3 is no less than to quantity, can stabilize the interval between coal slime sleeve pipe 2 and the perimeter wind sleeve pipe 4, prevent to rock. A peripheral wind channel (not shown in the figure) is formed between the adjacent first limit blocks 16, and certainly, for smooth flow of peripheral wind, the first limit blocks 16 should not be too large, so as to meet the actual engineering requirements. The upper part of the peripheral air sleeve 4 is connected with a peripheral air inlet pipe 6 communicated with the second annular cavity 13, and the outer wall of the peripheral air sleeve 4 is in full-sealing welding with fins on the heating surface of the furnace top.

The perimeter wind access pipe 6 and the coal slime access pipe 5 are positioned above the water-cooled wall of the furnace top. The coal slime access pipe 5 is positioned above the second sealing ring plate 8 of the perimeter wind casing pipe 4.

Center taper pipe 3 is the cavity setting, it contains reducing section and constant diameter section, reducing section cross-sectional diameter is for following the air inlet direction crescent, the diameter maximum position is connected with the constant diameter section, form third ring chamber 14 between reducing section outer wall and the 1 inner wall of central tuber pipe, set up round second stopper 9 and round third stopper 10 in third ring chamber 14, with the relative position of stable center taper pipe 3, the quantity of second stopper 9 and third stopper 10 is not less than 3, interval between firm center taper pipe 3 and the central tuber pipe 1 is even in order to guarantee outlet wind ring thickness, third stopper 10 and

central tuber pipe

1, 3 full weldings of central taper pipe, second stopper 9 only with 1 full weldings of central tuber pipe can.

The utility model discloses a fire side steel sheet in the combustor stove is coated with wear-resisting fire resistant coating in order to protect the steel sheet, increase of service life.

Based on the above structure of the utility model, adopt the furnace roof suction fan 17 on the spot to supply air for the combustor, the blast pipe 18 of furnace roof suction fan 17 export on the spot falls into 2 branch roads, connects central tuber pipe 1 and perimeter wind respectively and inserts pipe 6. A conventional check valve 181 and flow measuring device 182 are provided on the supply line 18. As shown in fig. 2, the secondary cold air pipeline 19 is connected to the air supply pipeline 18, the access point of the secondary cold air pipeline is located between the check valve 181 and the flow measuring device 182, and the secondary cold air pipeline 19 is sequentially provided with a conventional isolation door 191 and an adjusting door 192 (both electric and pneumatic).

When the top of the CFB boiler is provided with the conventional coal slime connector, because the upper part of a hearth belongs to an anoxic or low-oxygen region, coal slime volatile components and micro carbon particles which cannot be captured by the separator cannot be fully combusted and discharged out of the boiler, so that the contents of boiler flue gas q3 and q4 after the CFB boiler is mixed with coal slime are high.

Adopt the utility model discloses, when operation central tuber pipe 1 supplies wind to furnace through third ring chamber 14 and perimeter tuber pipe 6 ring chamber 13, the form coal slime that sticks together is pressed by the column from coal slime admission pipe 5 exit and is cyclic annular after, get into and fall in first ring chamber 12, a plurality of segmentation piece 7 that set up in first ring chamber 12 bottom separate into thinner strip with cyclic coal slime, from shaping passageway whereabouts to, coal slime sleeve pipe 1 sets up and effectively utilizes rich pressure of coal slime and gravity, it sticks together to become a plurality of little originally big lumps together, fall outside central tuber pipe 1 bottom, the mud strip receives furnace heat radiation all around in-process that falls down, the hot gas stream heating of central wind and perimeter wind is very cracked and releases the volatility, volatility and carbon granule meet direct blending with inside and outside air and burn, can make the unable flammable gas of catching of separator and tiny granule once only burn to the greatest extent, be favorable to reducing boiler q3, q4 is lost. In the process, the coal slime is conveyed under pressure, the water contained in the coal slime cannot be evaporated in a large amount in the conveying process, the flow resistance cannot be increased suddenly, and the coal slime cannot be blocked and can smoothly reach the outlet of the forming channel.

Meanwhile, the mud mass is integrated into strips to fall, so that the problems of bed fluidization dead zone, coking and boiler shutdown caused by insufficient thermal explosion of the mud mass falling into the bottom of the hearth are thoroughly solved.

Claims

1. A CFB boiler top coal slime granulation air distribution burner is characterized by being inserted into a water-cooled wall at the top of the CFB boiler, and the burner comprises a central conical pipe (3), a central air pipe (1), a coal slime sleeve pipe (2) and a peripheral air sleeve pipe (4) which are sequentially and concentrically sleeved inside and outside;

the inner wall of the coal slime casing pipe (2) and the outer wall of the central air pipe (1) form a first annular cavity (12), the top of the first annular cavity (12) is sealed, a plurality of partition blocks (11) are annularly distributed at the bottom of the first annular cavity (12), a forming channel is formed between every two adjacent partition blocks (11), and the upper part of the coal slime casing pipe (2) is connected with a coal slime access pipe (5) communicated with the first annular cavity (12);

a second annular cavity (13) is formed by the inner wall of the peripheral air casing pipe (4) and the outer wall of the coal slime casing pipe (2), the top of the second annular cavity (13) is sealed, a plurality of first limiting blocks (16) are annularly distributed in the second annular cavity (13), a peripheral air channel is formed between every two adjacent first limiting blocks (16), and a peripheral air access pipe (6) communicated with the second annular cavity (13) is connected to the upper part of the peripheral air casing pipe (4);

center taper pipe (3) contain reducing section and constant diameter section, reducing section cross-section diameter is crescent along with the air inlet direction, the diameter maximum position with the constant diameter section is connected, form third ring chamber (14) between reducing section outer wall and central tuber pipe (1) inner wall, at third ring chamber (14) interior ring-shaped a plurality of second stopper (9) and a plurality of third stopper (10) of laying.

2. The CFB boiler topped coal slime pelletizing and air distributing burner according to claim 1, wherein the top of the first annular chamber (12) is sealed by a first sealing annular plate (7), the top of the second annular chamber (13) is sealed by a second sealing annular plate (8), and the coal slime connecting pipe (5) is positioned above the second sealing annular plate (8) of the peripheral air casing pipe (4).

3. The CFB boiler topped coal slurry granulation air distribution burner as set forth in claim 1, wherein the coal slurry inlet pipe (5) and the peripheral air inlet pipe (6) are located above the furnace top water wall.

4. The CFB boiler topped coal slime pelletizing air distribution burner as set forth in claim 1, wherein the number of the first limiting block (16), the second limiting block (9) and the third limiting block (10) is not less than 3.

5. The CFB boiler topped coal slime pelletizing air distribution burner of claim 1, characterized in that the central conical pipe (3) is hollow.

6. The CFB boiler top coal slime granulation air distribution burner as claimed in claim 1, wherein the outer wall of the perimeter air sleeve (4) is hermetically and fully welded with the furnace top water wall, the partition block (11) is fully welded with the central air pipe (1) and the coal slime sleeve (2), the third limit block (10) is fully welded with the central air pipe (1) and the central taper pipe (3), and the second limit block (9) is fully welded with the central air pipe (1).

7. The CFB boiler topped coal slime pelletizing air distribution burner of claim 1, characterized in that the top of the partition block (11) is wedge-shaped.

8. The CFB boiler topped coal slime pelletizing air distribution burner according to any one of claims 1 to 7, characterized in that a furnace top local suction fan (17) is used for supplying air to the burner, an air supply pipeline (18) at the outlet of the furnace top local suction fan (17) is divided into 2 branches which are respectively connected with the central air pipe (1) and the peripheral air inlet pipe (6), and a spare secondary cold air pipeline (19) is further connected to the air supply pipeline (18).