CN203757699U - Circulating fluidized bed boiler with low-nitrogen combustion system - Google Patents
Circulating fluidized bed boiler with low-nitrogen combustion system Download PDFInfo
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- CN203757699U CN203757699U CN201420137953.8U CN201420137953U CN203757699U CN 203757699 U CN203757699 U CN 203757699U CN 201420137953 U CN201420137953 U CN 201420137953U CN 203757699 U CN203757699 U CN 203757699U
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- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims abstract description 54
- 229910052757 nitrogen Inorganic materials 0.000 title claims abstract description 28
- 238000002485 combustion reaction Methods 0.000 title abstract description 5
- 239000013589 supplement Substances 0.000 claims abstract description 12
- 239000000463 material Substances 0.000 claims abstract description 8
- 230000001105 regulatory effect Effects 0.000 claims abstract description 5
- 239000003245 coal Substances 0.000 claims description 33
- 239000000839 emulsion Substances 0.000 claims description 25
- 238000005299 abrasion Methods 0.000 claims description 7
- 239000011449 brick Substances 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 5
- 238000013461 design Methods 0.000 claims description 4
- 230000009466 transformation Effects 0.000 abstract description 28
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract description 17
- 230000008901 benefit Effects 0.000 abstract description 3
- 235000019504 cigarettes Nutrition 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000007613 environmental effect Effects 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 239000003344 environmental pollutant Substances 0.000 description 4
- 231100000719 pollutant Toxicity 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000004202 carbamide Substances 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 1
- 239000003830 anthracite Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002802 bituminous coal Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000003500 flue dust Substances 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 238000005243 fluidization Methods 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 239000003077 lignite Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000007634 remodeling Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000010977 unit operation Methods 0.000 description 1
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Abstract
The utility model discloses a circulating fluidized bed boiler with a low-nitrogen combustion system. The circulating fluidized bed boiler comprises a low-share primary air system PAS, a secondary air accurate supply system SAS, and a bed burner air supplement system SUBS, wherein a bell-type hood is arranged on an air distribution plate, and a fireproof and wear-resistant material boss is built on the outermost ring of the air distribution plate; the quantity of the secondary air SA is independently supplied and is respectively regulated by a regional secondary air total flow control device and an independent secondary air accurate flow control device; a secondary air port is divided into three layers or four layers along the height direction of a dense-phase zone in a hearth; an air source is primary cold air PAC; the quantity of bed burner air SUBA accounts for 5-10 percent of the total air TA quantity. The ratio of the primary and secondary air can be flexibly adjusted after transformation, accurate control of combustion air supply is ensured, and low nitric oxide emission level and high combustion efficiency are finally realized. Without additionally arranging equipment, environment-friendly operating characteristics of the boiler are obviously improved, and the circulating fluidized bed boiler has the advantages of low investment cost, short transformation period, zero operating cost, stable boiler operation and the like.
Description
Technical field
The utility model belongs to CFBB environmental technology field, is specifically related to a kind of CFBB with low nitrogen burning system.
Background technology
Coal is the main source of China's primary energy, and coal fired power generation is the major part that coal in China is utilized.Coal burning will produce a lot of pollutants, and as sulfur dioxide, nitrogen oxide and flue dust etc., wherein nitrogen oxide is one of main source of acid rain formation.Along with the fast development of China's economy, pollutant emission is more serious, has brought great puzzlement to people's lives.Given this, country issues environmental regulation and strictly controls the discharge of pollutant in succession." fossil-fuel power plant atmospheric pollutant emission standard " of up-to-date promulgation (GB13223-2011) in clear and definite regulation, from 1 day July in 2014, existing CFBB emission limits of nitrogen oxides was 200mg/m
3.
Domestic existing Properties of CFB, because coal type change is large and air flow rate proportioning regulates the factors such as unreasonable, causes a lot of power plant to be difficult to up to standard.In actual moving process, although some unit has adopted the scheme of a Secondary Air classification burning, due to emulsion zone excess Temperature, it is 60% even high that the ratio that wind accounts for total blast volume has to mention, be unfavorable for like this generation of reducing atmosphere, be also just unfavorable for that the generation of nitrogen oxide suppresses.Due to a considerable amount of CFB boiler NO
xconcentration of emission exceedes 200mg/m
3, SNCR denitrating system need to be installed, this can significantly increase the operating cost of enterprise and the transformation cycle is long, investment of equipment is very big.Under such background, in order to strengthen the flexibility of existing Properties of CFB air flow rate proportioning adjusting, the utility model proposes a kind of low nitrogen burning remodeling method of CFBB.
Summary of the invention
The problem existing in order to solve above-mentioned prior art, the purpose of this utility model is to provide a kind of CFBB with low nitrogen burning system, can give full play to the environmental protection characteristic of CFB boiler, meet the requirement of national up-to-date environmental protection standard, reduce the cost that removes out of nitrogen oxide.
In order to realize above-mentioned utility model object, the technical scheme that the utility model is taked is:
With a CFBB for low nitrogen burning system, comprise that the upper burner of low share primary air system PAS, the accurate feed system SAS of Secondary Air and bed supplements wind system SUBS; Described low share primary air system PAS is provided with bell-type windshield 5 on air distribution plate 4, described bell-type windshield 5 spacing 100～400mm each other, and wind PA amount of run duration accounts for 15～40% of the total wind TA amount of burning; In the time that wind PA amount accounts for the total wind TA amount ratio of burning and is 15%, the resistance of bell-type windshield 5 is 1～2kPa; Built Fire and abrasion resistant material boss 6 by laying bricks or stones in air distribution plate 4 outmost turns, the height of described boss 6 is that 200～600mm, width are 400～600mm; The accurate feed system SAS of described Secondary Air, Secondary Air SA amount is independently supplied with according to region, regulated by region Secondary Air total flow control device 13 and independent Secondary Air accurate flow control unit 14 respectively, overfiren air port 7 is divided into 3 layers or 4 layers of layout along burner hearth emulsion zone 1 short transverse; The upper burner of described bed supplements wind system SUBS, and wind regime is a cold wind PAC, and on bed, the amount of burner wind SUBA accounts for 5%～10% of the total wind TA amount of burning.
When described overfiren air port 7 divides 3 layers to arrange along burner hearth emulsion zone 1 short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm apart from the height of air distribution plate 4; When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm apart from the height of air distribution plate 4; When boiler uses coal more than dry ash free basis Vdaf30%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm apart from the height of air distribution plate 4.
When described overfiren air port 7 divides 4 layers to arrange along burner hearth emulsion zone 1 short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm, 3600～4000mm apart from the height of air distribution plate 4; When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm, 4000～4500mm apart from the height of air distribution plate 4; When boiler uses coal more than dry ash free basis Vdaf25%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm, 4400～4800mm apart from the height of air distribution plate 4.
The overfiren air port 7 position stagger arrangement of described adjacent two layers are arranged and are put, and the difference in height being staggered in arrangement is 200～400mm.
Vertical range and the horizontal range of described overfiren air port 7 positional distance coal feeding hole 9 positions are all greater than 800mm.
Described overfiren air port 7 is 15～75 ° with the angle α of vertical direction, with the angle β of horizontal direction be 5～80 °.
Described overfiren air port 7 is positive square opening, rectangular mouth, round mouth, oval mouthful or trapezoidal mouth, and its end employing gradual change design, and it is 50%～200% of Secondary Air pipeline 8 equivalent diameters that overfiren air port 7 exports equivalent diameter.
Compared with prior art, the utlity model has following advantage:
1. most of CFB boiler adopts this Techniques For Reducing NO
xafter concentration of emission, without adopting any auxiliary denitration technology, fume emission can meet national up-to-date environmental protection standard requirement, obvious environment benefit.
2. small part CFB boiler is due to original NO
xconcentration of emission is higher, adopts the utility model significantly to cut down NO
xconcentration of emission (after transformation, NOx concentration can be reduced to 40%～70% before transformation in boiler emission flue gas), can significantly reduce the reducing agent consumption of SNCR denitrating system, reduces the operating cost of system.
3. the utility model is without carrying out any transformation to blower fan system, can realize low primary air flow operation, do not affect boiler combustion, due to newly added equipment not, do not increase the repair and maintenance workload of existing equipment.
4. the utility model no longer needs simple increase primary air flow to come regulating stove bore temperature and oxygen content, can significantly reduce blast cap wearing and tearing.
5. the utility model can strengthen the supply ratio of Secondary Air and the flexible adjustment of raising Secondary Air, further improves economy and the feature of environmental protection of unit operation.
Brief description of the drawings
Fig. 1 is the overall structure schematic diagram before a CFBB low nitrogen burning transformation is implemented.
Fig. 2 is the cigarette wind flow chart before a CFBB low nitrogen burning transformation is implemented.
Fig. 3 is the burner hearth opening figure before a CFBB low nitrogen burning transformation is implemented.
Fig. 4 is the overall structure schematic diagram after a CFBB low nitrogen burning transformation is implemented.
Fig. 5 is the cigarette wind flow chart after a CFBB low nitrogen burning transformation is implemented.
Fig. 6 is the burner hearth opening figure after a CFBB low nitrogen burning transformation is implemented.
Fig. 7 is the accurate feed system control mode of the Secondary Air schematic diagram after low nitrogen burning transformation is implemented.
Fig. 8 is that the Fire and abrasion resistant material boss after low nitrogen burning transformation is implemented arranges schematic diagram.
Fig. 9 is the overfiren air port profile schematic diagram after low nitrogen burning transformation is implemented.
Figure 10 is the overfiren air port gradual change design diagram after low nitrogen burning transformation is implemented.
Figure 11 compares before and after a upper burner supplements wind system transformation.
In figure:
1---burner hearth emulsion zone 2---burner hearth dilute-phase zone
3---air compartment 4---air distribution plate
5---bell-type windshield 6---Fire and abrasion resistant material boss
7---overfiren air port 8---secondary air duct
9---coal feeding holes 10---air port of burning on bed
11---burner 12 on bed---air preheater
13---region Secondary Air total flow control device 14---independent Secondary Air accurate flow control unit
15---returning charge mouth
α---angle β of overfiren air port and the vertical direction---angle of overfiren air port and horizontal direction
The accurate feed system of PAS---primary air system SAS---Secondary Air
SUBS---on bed, burner supplements wind system
A cold wind of PA---a wind PAC---
PAH a---hot blast
SA---Secondary Air SAC---secondary cold wind
SAH---secondary hot-air
TA---total wind burns
SUBA---burner wind on bed
Detailed description of the invention
Below in conjunction with drawings and the specific embodiments, the utility model is described in further detail.
As shown in Fig. 1～Fig. 7, a kind of CFBB with low nitrogen burning system, comprises that the upper burner of low share primary air system PAS, the accurate feed system SAS of Secondary Air and bed supplements wind system SUBS; Described low share primary air system PAS is provided with bell-type windshield 5 on air distribution plate 4, has built Fire and abrasion resistant material boss 6 by laying bricks or stones in air distribution plate 4 outmost turns; The accurate feed system SAS of described Secondary Air, Secondary Air SA amount is independently supplied with according to region, regulated by region Secondary Air total flow control device 13 and independent Secondary Air accurate flow control unit 14 respectively, overfiren air port 7 is divided into 3 layers or 4 layers of layout along burner hearth emulsion zone 1 short transverse; The upper burner of described bed supplements wind system SUBS, for example makes up the deficiency (part of generating units exists the problem of overfire air fan surplus deficiency) of secondary air flow, a upper burner is set and supplements wind system afterburning burning wind, wind regime is a cold wind PAC, and on bed, the amount of burner wind SUBA accounts for 5%～10% of the total wind TA amount of burning.Can realize low nitrogen burning transformation without carrying out secondary air system increase-volume.
As shown in Figure 8, as preferred embodiment of the present utility model, described bell-type windshield 5 spacing 100～400mm each other, wind PA amount of run duration accounts for 15～40% of the total wind TA amount of burning; The fluidisation that may occur in the time that primary air flow declines is bad and leak slag, and in the time that a wind PA amount accounts for the total wind TA amount ratio of burning and is 15%, it is 1～2kPa that the resistance of bell-type windshield 5 ensures.
As shown in Figure 8, as preferred embodiment of the present utility model, the height of described boss 6 is that 200～600mm, width are 400～600mm.This boss is used for preventing air distribution plate peripheral regions and occurs that bell-type windshield stops up.
As preferred embodiment of the present utility model, when described overfiren air port 7 divides 3 layers to arrange along burner hearth emulsion zone 1 short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm apart from the height of air distribution plate 4; When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm apart from the height of air distribution plate 4; When boiler uses coal more than dry ash free basis Vdaf30%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm apart from the height of air distribution plate 4.
As preferred embodiment of the present utility model, when described overfiren air port 7 divides 4 layers to arrange along burner hearth emulsion zone 1 short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm, 3600～4000mm apart from the height of air distribution plate 4; When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm, 4000～4500mm apart from the height of air distribution plate 4; When boiler uses coal more than dry ash free basis Vdaf25%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm, 4400～4800mm apart from the height of air distribution plate 4.
As preferred embodiment of the present utility model, too high for fear of local oxygen concentration, the overfiren air port 7 position stagger arrangement of adjacent two layers are arranged and are put, and the difference in height being staggered in arrangement is 200～400mm.
As preferred embodiment of the present utility model, vertical range and the horizontal range of described overfiren air port 7 positional distance coal feeding hole 9 positions are all greater than 800mm.
As preferred embodiment of the present utility model, described overfiren air port 7 is 15～75 ° with the angle α of vertical direction, with the angle β of horizontal direction be 5～80 °.
As shown in Figure 9 and Figure 10, as preferred embodiment of the present utility model, described overfiren air port 7 is positive square opening, rectangular mouth, round mouth, oval mouthful or trapezoidal mouth, and its end employing gradual change design, and it is 50%～200% of Secondary Air pipeline 8 equivalent diameters that overfiren air port 7 exports equivalent diameter.
As shown in figure 11, for burner on bed supplements wind system transformation front and back relatively, transform a front cold wind PAC and become hot blast PAH one time after air preheater 12 heating, a hot blast PAH of a part is sent into as burner wind SUBA on bed by burner on bed 11, and a hot blast PAH of a part is sent into as a wind PA by air compartment 3; Secondary cold wind SAC becomes secondary hot-air SAH after air preheater 12 heating, and a part of secondary hot-air SAH is sent into as burner wind SUBA on bed by burner on bed 11, and a part of secondary hot-air SAH is sent into as Secondary Air SA by secondary air duct 8.
On transformation external crucible, the wind regime of burner wind SUBA is hot blast PAH or secondary hot-air SAH.
Transform a rear cold wind PAC and be divided into two parts, cold wind PAC of a part becomes hot blast PAH one time after air preheater 12 heating, is sent into as a wind PA by air compartment 3; A cold wind PAC of a part is sent into as burner wind SUBA on bed by burner on bed 11.
After transformation, the wind regime of the upper burner wind SUBA of bed is a cold wind PAC.
Embodiment 1
Referring to Fig. 1～Fig. 6, relate to 1 480t/h CFBB, boiler uses the bituminous coal of dry ash free basis Vdaf20%, boiler secondary air divides the short transverse of cigarette burner hearth emulsion zone 1 to divide two-layer SA1, SA2 to send into, one time wind PA amount accounts for 60% of total wind TA amount, and the NOx concentration of emission of run duration is 250mg/m
3.
First cooling by wind PAC becomes hot blast PAH one time through air preheater 12, then sends into burner hearth emulsion zone 1 by air compartment 3 as a wind PA; Secondary cold wind becomes secondary hot-air SAH through air preheater 12, is then divided into two-way, and burner hearth emulsion zone 1 is sent into as burner wind SUBA on bed in a road from the bed burner 11, from sending into burner hearth emulsion zone 1 from secondary air duct 8 as Secondary Air SA.
After boiler, wall and front wall respectively offer two row's overfiren air ports 7, the height of the independent air distribution plate 4 of ground floor overfiren air port 7 is 400mm, the height of the independent air distribution plate 4 of second layer overfiren air port 7 is 4500mm, the each overfiren air port 7 of ground floor is in same level, and the each overfiren air port 7 of the second layer is also in same level.Overfiren air port 7 is 30 ° with the angle α of vertical direction, with the angle β of horizontal direction be 0 °.
For reducing NO in boiler smoke
xconcentration of emission, boiler is carried out to low nitrogen burning transformation, concrete transformation comprises:
Low share primary air system PAS is provided with bell-type windshield 5 on air distribution plate 4, bell-type windshield 5 spacing 150mm each other, and in the time that wind PA amount accounts for the total wind TA amount ratio of burning and is 15%, the resistance of bell-type windshield 5 is 1kPa.Air distribution plate 4 outmost turns are built the Fire and abrasion resistant material boss 6 of height 400mm, width 500mm by laying bricks or stones.
One time wind PA amount accounts for 40% of total wind TA amount, and not enough wind regime supplements by increasing the upper burner wind SUBA amount of Secondary Air SA amount and bed, and wherein the upper burner wind SUBA amount of bed accounts for 10% of the total wind TA amount of burning.
First cooling by wind PAC becomes hot blast PAH one time through air preheater 12, is then divided into two-way, and a road from the bed burner 11 is sent into burner hearth emulsion zone 1, one road as burner wind SUBA on bed and sent into burner hearth emulsion zone 1 from air compartment 3 as a wind PA; Secondary cold wind becomes secondary hot-air SAH through air preheater 12, sends into burner hearth emulsion zone 1 from secondary air duct 8 as Secondary Air SA.
After boiler, wall and front wall respectively offer three row's overfiren air ports 7, and overfiren air port 7 adopts round mouth, and it is 150% of Secondary Air pipeline 8 water conservancy diameters that overfiren air port 7 exports water conservancy diameter.
The height of the independent air distribution plate 4 of ground floor overfiren air port 7 is 1000mm, the height of the independent air distribution plate 4 of second layer overfiren air port 7 is 2500mm, the height of the 3rd layer of independent air distribution plate 4 of overfiren air port 7 is 3500mm, the each overfiren air port 7 of ground floor adopts and is staggered in arrangement, difference in height is 200mm, and the each overfiren air port 7 of the second layer adopts and is staggered in arrangement, and difference in height is 400mm, the 3rd layer of each overfiren air port 7 adopts and is staggered in arrangement, and difference in height is 300mm.Overfiren air port 7 is 45 ° with the angle α of vertical direction, and overfiren air port 7 is 15 ° with the angle β of horizontal direction.
The generation of NOx while burning in order to reduce, front wall overfiren air port 7 positional distances are that 1000mm and horizontal range are 1200mm to the vertical range of front wall coal mouth 9 positions.
After above-mentioned transformation is implemented, the NOx concentration of emission of run duration is reduced to 180mg/m
3.
Embodiment 2
Relate to 1 1024t/h CFBB, boiler uses the brown coal of dry ash free basis Vdaf40%, boiler secondary air divides the short transverse of cigarette burner hearth emulsion zone 1 to divide two-layer SA1, SA2 to send into, one time wind PA amount accounts for 55% of total wind TA amount, after boiler, wall and front wall respectively offer two row's overfiren air ports 7, and the NOx concentration of emission of run duration is 350mg/m
3.For reducing NO in boiler smoke
xconcentration of emission, adopt SNCR technology to carry out denitration, a year urea consumption is 8000 tons.
Boiler is carried out to low nitrogen burning transformation, and concrete transformation comprises:
First cooling by wind PAC becomes hot blast PAH one time through air preheater 12, is then divided into two-way, and burner hearth emulsion zone 1 is sent into as burner wind SUBA on bed in a road from the bed burner 11, and on bed, burner wind SUBA amount accounts for 8% of the total wind TA amount of burning.
Boiler secondary air divides the short transverse of cigarette burner hearth emulsion zone 1 to divide three layers of SA1, SA2, SA3 to send into, and overfiren air port 7 adopts positive square opening, and it is 120% of Secondary Air pipeline 8 water conservancy diameters that overfiren air port 7 exports water conservancy diameter.The generation of NOx while burning in order to reduce, front wall overfiren air port 7 positional distances are that 1200mm and horizontal range are 1500mm to the vertical range of front wall coal mouth 9 positions.
After above-mentioned transformation is implemented, the NOx concentration of emission of run duration is reduced to 220mg/m
3, still adopt SNCR technology to carry out denitration, but a year urea consumption is reduced to 2000 tons.
Embodiment 3
Relate to 1 newly-built 410t/h CFBB, boiler uses the anthracite of dry ash free basis Vdaf10%, boiler secondary air divides the short transverse of cigarette burner hearth emulsion zone 1 to divide four layers of SA1, SA2, SA3, SA4 to send into, low share primary air system PAS is provided with bell-type windshield 5 on air distribution plate 4, bell-type windshield 5 spacing 200mm each other, air distribution plate 4 outmost turns are built the Fire and abrasion resistant material boss 6 of height 400mm, width 400mm by laying bricks or stones.
One time wind PA amount accounts for 40% of total wind TA amount, and Secondary Air SA amount accounts for 50% of total wind TA amount, and on bed, burner wind SUBA amount accounts for 10% of total wind TA amount.First cooling by wind PAC becomes hot blast PAH one time through air preheater 12, is then divided into two-way, and a road from the bed burner 11 is sent into burner hearth emulsion zone 1, one road as burner wind SUBA on bed and sent into burner hearth emulsion zone 1 from air compartment 3 as a wind PA; Secondary cold wind becomes secondary hot-air SAH through air preheater 12, sends into burner hearth emulsion zone 1 from secondary air duct 8 as Secondary Air SA.
After boiler, wall and front wall respectively offer four row's overfiren air ports 7, and overfiren air port 7 adopts rectangular mouthful, and it is 80% of Secondary Air pipeline 8 water conservancy diameters that overfiren air port 7 exports water conservancy diameter.
The height of the independent air distribution plate 4 of ground floor overfiren air port 7 is 800mm, the height of the independent air distribution plate 4 of second layer overfiren air port 7 is 1800mm, the height of the 3rd layer of independent air distribution plate 4 of overfiren air port 7 is 2800mm, the height of the 4th layer of independent air distribution plate 4 of overfiren air port 7 is 3800mm, the each overfiren air port 7 of ground floor adopts and is staggered in arrangement, difference in height is 200mm, the each overfiren air port 7 of the second layer adopts and is staggered in arrangement, difference in height is 200mm, the 3rd layer of each overfiren air port 7 adopts and is staggered in arrangement, difference in height is 300mm, the 4th layer of each overfiren air port 7 adopts and is staggered in arrangement, difference in height is 300mm.Overfiren air port 7 is 30 ° with the angle α of vertical direction, and overfiren air port 7 is 10 ° with the angle β of horizontal direction.
The generation of NOx while burning in order to reduce, front wall overfiren air port 7 positional distances are that 1000mm and horizontal range are 1000mm to the vertical range of front wall coal mouth 9 positions.
After above-mentioned transformation is implemented, the NOx concentration of emission of run duration is reduced to 95mg/m
3.
Embodiment 4
Referring to Fig. 7, no matter be original boiler improvement and newly constructed boiler, run duration regulates the region Secondary Air total flow of front wall, Hou Qiang, Zuo Qiang, right wall by region Secondary Air total flow control device 13, wherein adopt the boiler of front wall coal supply, the region Secondary Air total flow of Hou Qiang, Zuo Qiang, right wall is greater than front wall; The boiler of wall revert system coal supply after adopting, the region Secondary Air total flow of front wall, Zuo Qiang, right wall is greater than rear wall; Adopt front wall, the rear wall boiler of coal supply simultaneously, the region Secondary Air total flow of Zuo Qiang, right wall is greater than front wall, Hou Qiang.
Independent Secondary Air accurate flow control unit 14 can accurately regulate the air quantity of each overfiren air port 7 as required, and the airflow value of each overfiren air port 7 is determined by field trial.
The description of above embodiment is comparatively concrete; but can not therefore be interpreted as the restriction to the utility model scope; for the person of ordinary skill of the art; without departing from the concept of the premise utility; some distortion and the improvement made, these all belong to protection domain of the present utility model.
Claims (7)
1. with a CFBB for low nitrogen burning system, it is characterized in that: comprise that the upper burner of low share primary air system PAS, the accurate feed system SAS of Secondary Air and bed supplements wind system SUBS;
Described low share primary air system PAS is provided with bell-type windshield (5) on air distribution plate (4), described bell-type windshield (5) spacing 100～400mm each other, and wind PA amount of run duration accounts for 15～40% of the total wind TA amount of burning; In the time that wind PA amount accounts for the total wind TA amount ratio of burning and is 15%, the resistance of bell-type windshield (5) is 1～2kPa; Built Fire and abrasion resistant material boss (6) by laying bricks or stones in air distribution plate (4) outmost turns, the height of described boss (6) is that 200～600mm, width are 400～600mm; The accurate feed system SAS of described Secondary Air, Secondary Air SA amount is independently supplied with according to region, regulated by region Secondary Air total flow control device (13) and independent Secondary Air accurate flow control unit (14) respectively, overfiren air port (7) is divided into 3 layers or 4 layers of layout along burner hearth emulsion zone (1) short transverse;
The upper burner of described bed supplements wind system SUBS, and wind regime is a cold wind PAC, and on bed, the amount of burner wind SUBA accounts for 5%～10% of the total wind TA amount of burning.
2. a kind of CFBB with low nitrogen burning system according to claim 1, it is characterized in that: when described overfiren air port (7) divides 3 layers to arrange along burner hearth emulsion zone (1) short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm apart from the height of air distribution plate (4); When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm apart from the height of air distribution plate (4); When boiler uses coal more than dry ash free basis Vdaf30%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm apart from the height of air distribution plate (4).
3. a kind of CFBB with low nitrogen burning system according to claim 1, it is characterized in that: when described overfiren air port (7) divides 4 layers to arrange along burner hearth emulsion zone (1) short transverse, the discrepancy in elevation difference of each layer, when boiler uses dry ash free basis Vdaf lower than 10% coal, be respectively 600～1000mm, 1600～2000mm, 2600～3000mm, 3600～4000mm apart from the height of air distribution plate (4); When boiler uses the coal of dry ash free basis Vdaf10%～25%, be respectively 1000～1500mm, 2000～2500mm, 3000～3500mm, 4000～4500mm apart from the height of air distribution plate (4); When boiler uses coal more than dry ash free basis Vdaf25%, be respectively 1400～1800mm, 2400～2800mm, 3400～3800mm, 4400～4800mm apart from the height of air distribution plate (4).
4. according to a kind of CFBB with low nitrogen burning system described in claim 2 or 3, it is characterized in that: overfiren air port (7) the position stagger arrangement of described adjacent two layers is arranged and put, and the difference in height being staggered in arrangement is 200～400mm.
5. a kind of CFBB with low nitrogen burning system according to claim 1, is characterized in that: vertical range and the horizontal range of described overfiren air port (7) positional distance coal feeding hole (9) position are all greater than 800mm.
6. a kind of CFBB with low nitrogen burning system according to claim 1, is characterized in that: the angle α of described overfiren air port (7) and vertical direction is 15～75 °, with the angle β of horizontal direction be 5～80 °.
7. a kind of CFBB with low nitrogen burning system according to claim 1, it is characterized in that: described overfiren air port (7) is positive square opening, rectangular mouth, round mouth, oval mouthful or trapezoidal mouth, and its end adopts gradual change design, overfiren air port (7) outlet equivalent diameter is 50%～200% of Secondary Air pipeline 8 equivalent diameters.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201420137953.8U CN203757699U (en) | 2014-03-25 | 2014-03-25 | Circulating fluidized bed boiler with low-nitrogen combustion system |
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| CN201420137953.8U CN203757699U (en) | 2014-03-25 | 2014-03-25 | Circulating fluidized bed boiler with low-nitrogen combustion system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107191922A (en) * | 2017-06-29 | 2017-09-22 | 平湖热电厂 | Low nitrogen burning CFBB |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107191922A (en) * | 2017-06-29 | 2017-09-22 | 平湖热电厂 | Low nitrogen burning CFBB |
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