CN209371229U - A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning - Google Patents

A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning Download PDF

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CN209371229U
CN209371229U CN201821748919.9U CN201821748919U CN209371229U CN 209371229 U CN209371229 U CN 209371229U CN 201821748919 U CN201821748919 U CN 201821748919U CN 209371229 U CN209371229 U CN 209371229U
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flue gas
air
arch
injector
recycled
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赵钦新
王兴乔
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Xian Jiaotong University
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Xian Jiaotong University
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Abstract

A kind of fuel-air flue gas three of the utility model is classified the grate firing boiler and its system of low nitrogen burning; the boiler includes face arch and corresponding rear arch; burner hearth, aditus laryngis and the combustion chamber that face arch and rear arch sequentially form from top to bottom; and the conveyer belt below burner hearth, it can ensure that the completely burned off of volatile matter;In the system, a certain amount of vapor that partial recirculation flue gas and steam generator of the blending from the outlet of smoke evacuation air-introduced machine generate in the First air that other wind cabins in addition to the wind distributing bin that volatilizees are sent into, flue gas recycled can reduce the oxygen content for being passed through the First air of fire grate, and vapor occurs water gas reaction and generate CO and H on fire grate with red-hot coke2, part gas-solid reaction is converted to gas phase reaction, another aspect CO can increase the reduction zone thickness above coal seam, effectively restore the NO that coal combustion generatesx;Under conditions of not adding large-scale subsidiary engine equipment, NO can be actively reducedxGeneration, realize energy conservation and emission reduction double goal.

Description

A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning
Technical field
The utility model relates to grate firing boilers to control discharged nitrous oxides technical field, specially a kind of fuel-air flue gas The grate firing boiler and its system of three classification low nitrogen burnings.
Background technique
China's coal-burned industrial boiler ownership is about 400,000, and annual quota of expenditure coal is up to more than 400,000,000 tons of standard coals, Zhan Quan The 20% of the coal-fired total amount consumed of state year.By the end of the year 2016, the northern area of China urban and rural buildings are warmed oneself about 20,600,000,000 squares of the gross area Rice, wherein fire coal is the major way of northern China house heating energy, and northern China coal heating area accounts for about total heating area 83%, natural gas, electric energy, geothermal energy, biomass energy, solar energy, industrial exhaust heat etc. are total to account for about 17%.Coal-burned industrial boiler Energy consumption and gross contamination emission are huge, be cause air quality deteriorate and the primary pollution source that takes place frequently of haze weather it One.In order to accelerate transformation of the mode of economic development, carries forward vigorously socialist ecological civilization and build, during " 12th Five-Year Plan ", country goes out Newest standards of the platform in relation to controlling air Contaminations of Coal Burning Boilers, drug in some provinces and area are worked out herein in connection with own situation Region laws and regulations, have made stringenter limitation to the emission level of nitrogen oxides from coal-fired boiler.In environmental protection standard Increasingly stringent today, to high energy consumption, high pollution, it is extremely urgent that the coal-burned industrial boiler of maximum discharge carries out denitration transformation. In the coal-burned industrial boiler in China, layer combustion chain-grate boiler has accounted for 60% or more of sum.Therefore, develop layer and fire chain-grate boiler NOxIt is particularly important to improve air quality to atmosphere pollution is mitigated for emission-reduction technology.
In recent years, China scientific research personnel has carried out the correlative study of the low nitrogen burning renovation technique of layer burner, obtains Many achievements, but the prior art remains in First air, Secondary Air fractional combustion and flue gas recirculation combination technique and reduces On the primary level of nitrogen oxides, method is usually that flue gas recycled is all sent into air blower or fire grate wind as First air Under storehouse, forward and backward chimney arch Secondary Air can not be thus arranged in forward and backward by the reducing zone of flue gas recycled adjustment burning The aditus laryngis of chimney arch reduces the reducing zone of burner hearth flue gas again, at the same Secondary Air can also overheavy firing to increase NOxOriginal life At, therefore this technology is only capable of the original NO of layer burnerxIt discharges from 400mg/m3It is reduced to 200mg/m3Left and right, remaining NOx There is still a need for can just be reduced to 50mg/m using SNCR or SCR3Below.Though traditional furnace arch structure can effectively improve the burning of boiler Efficiency, but it excessively emphasizes the importance that new coal ignites with overheavy firing, and ignore from inhibiting NO in combustion process on sourcex Generation.Have that removal efficiency is undesirable, and there are secondary pollutions again according to the denitrating flue gas such as SCR/SNCR in furnace processing technique A series of problems, such as risk, high operating cost.
Utility model content
Aiming at the problems existing in the prior art, the utility model provides a kind of classification of fuel-air flue gas three low nitrogen burning Grate firing boiler and its system, under conditions of not adding large-scale subsidiary engine equipment, by divide burner hearth classification combustion is carried out to fuel It burns, can actively reduce NOxGeneration, realize energy conservation and emission reduction double goal.
The utility model is to be achieved through the following technical solutions:
A kind of fuel-air flue gas three is classified the grate firing boiler of low nitrogen burning, including face arch and corresponding rear arch, preceding Encircle the conveyer belt below the burner hearth, aditus laryngis and the combustion chamber that sequentially form from top to bottom with rear arch and burner hearth;
The segmentation refractory wall to break it into two is provided in the burner hearth, segmentation refractory wall and face arch form precombustion chamber As volatile matter pyrolysis and combustion area, divides refractory wall and rear arch forms coke combustion zone;Divide on refractory wall lower end and conveyer belt Coal seam between form gap, for through the flue gas and radiant heat in coke combustion zone in burner hearth, so that waving in precombustion chamber It sends out divided combustion and coke does not burn;
The top of the precombustion chamber is equipped with the face arch flue gas recycled injector for being located at segmentation refractory wall, and face arch recycles cigarette Gas injection device be used for by precombustion chamber uplink flue gas and uncombusted volatile matter be injection to aditus laryngis;
The rear arch is equipped with rear arch flue gas recycled injector at aditus laryngis, and face arch two is arranged in secondary furnace at aditus laryngis Secondary wind spray head and rear arch Secondary Air spray head.
Preferably, several wind cabins corresponding with its top coal seam are provided with below the conveyer belt, with pyrolysis and combustion area Corresponding is volatilization wind distributing bin, is symmetrically arranged with high temperature flue gas ejector in the wind distributing bin that volatilizees;In coke combustion zone close to segmentation The hearth biside wall face of refractory wall opens up circular hole respectively, and the part high-temperature flue gas in burner hearth passes through flue stream outside side wall to high temperature Flue gas ejector, high-temperature flue gas is by the fire grate that is passed through above the flue gas recycled injection of high temperature flue gas ejector to volatilization wind distributing bin Face.
Further, the position that the hearth biside wall face opens up circular hole should be close to the reducing zone of burner hearth, and is not higher than face arch Secondary Air spray head and rear arch Secondary Air spray head.
Preferably, secondary furnace horizontally-opposed row front arch secondary air spray head and row's rear arch Secondary Air spray at aditus laryngis Head;The angle of the front arch secondary air spray head and rear arch Secondary Air spray head can be sprayed by -15 ° on the basis of level~45 ° Penetrate the adjusting in direction.
Preferably, the mounting height of the face arch flue gas recycled injector is higher than rear arch flue gas recycled injector.
Preferably, face arch flue gas recycled injector is disposed with jet pipe of the row towards aditus laryngis;The spray of rear arch flue gas recycled Emitter is disposed with jet pipe of the row towards the jet pipe and a row of segmentation refractory wall towards coke combustion zone below rear arch, two rows of nozzles Between angle be 1 °~120 °.
Preferably, deposited refractory material is made after the segmentation refractory wall welds bitch by steel plate two sides;Divide on refractory wall Portion opens up scaling spout, and scaling spout is the conduit that a section is de Laval noz(zle), the nozzle of face arch flue gas recycled injector It is set at the aditus laryngis of scaling spout.
A kind of fuel-air flue gas three is classified the grate firing boiler system of low nitrogen burning, including layer described in above-mentioned any one Combusting boiler is connected to hot end, deduster, air-introduced machine and the chimney of the air preheater of grate firing boiler flue in turn;
Flue between the air-introduced machine and chimney is provided with flue gas recycled pipeline, recycled in circulating flue gas pipeline Smoke induced draught fan is respectively connected to face arch flue gas recycled injector, rear arch flue gas recycled injector and high-temperature flue gas injection Device;
The lower section of the conveyer belt is equipped with fire grate distribution plenum, and the output end of fire grate distribution plenum is separately connected except volatile matter wind Other wind cabins other than storehouse;
Cold end of the First air successively through First air air-introduced machine, air preheater connects fire grate distribution plenum with steam generator Input terminal.
Further, when fire grate distribution plenum air distribution, fire grate is corresponding and subsequent each below rear arch flue gas recycled injector Wind cabin is greater than remaining each wind cabin air quantity with air quantity.
Compared with prior art, the utility model has technical effect beneficial below:
In grate firing boiler described in the utility model, divides refractory wall for burner hearth and be divided into volatile matter pyrolysis and combustion area and coke Charcoal combustion zone two parts divide the face arch that refractory wall acts as coal seam of igniting, the combustion process in coal seam due to setting up for precombustion chamber It is postponed, is equivalent to the effective length for shortening conveyer belt lower fire grating face.It will form one between segmentation refractory wall lower end and coal seam A lesser gap, flue gas and radiant heat in burner hearth can enter in precombustion chamber through the gap.The coal according to used in boiler Kind the characteristics of, the size in the gap need to be suitably set, with guarantee to be enough to ignite through a small amount of flue gas and radiant heat that come burning point compared with Low volatile matter, and be unlikely to that coke is made to burn.Most of volatile carries out in the lower reducing atmosphere of oxygen content Burning, to significantly reduce the NO as caused by volatile matter nitrogenxYield;The volatile matter of not yet after-flame mix with flue gas gas be heated it is swollen It is swollen, accelerate to go upward to the top of precombustion chamber, flue gas recycled be pyrolyzed from face arch flue gas recycled injector injection precombustion chamber with The gas that burning generates be carried along at the aditus laryngis of burner hearth and the flue gas recycled that is sprayed with rear arch flue gas recycled injector into Row NOxReduction burning.Most the front arch secondary air spray head through upper layer and rear arch Secondary Air spray head carry out the further of Secondary Air afterwards Burning, to ensure the completely burned off of volatile matter.
Further, circular hole is opened up on the hearth biside wall face close to segmentation refractory wall, the part high temperature cigarette in burner hearth Gas is mixed along the nozzle throat of flue stream outside side wall to high temperature flue gas ejector then by low temperature flue gas recycled injection Hot fume afterwards is flow at the grate surface above volatile matter wind cabin after spraying along flue, and effect is for coal seam pyrolysis and volatile matter It ignites and heat is provided, and the temperature in coal seam is not caused to reach coke burning point and coke is caused to burn, what coal seam pyrolysis generated waves Hair point is carried along into precombustion chamber by the flue gas of uplink.
Further, to guarantee that the oxygen content of institute's injection high-temperature flue gas is as low as possible, should suitably raise circular hole opens up position It sets, with the reducing zone as close as possible to burner hearth, but front arch secondary air spray head and rear arch Secondary Air spray head must not be higher than.
Further, front arch secondary air spray head and the opposed injection Secondary Air of rear arch Secondary Air spray head are to strengthen the combustion of combustible To the greatest extent, the angle of the front arch secondary air spray head and rear arch Secondary Air spray head can according to coal-fired type on the basis of by level- The adjusting of 15 °~45 ° progress injection directions, to realize the fractional combustion of air.
Further, the mounting height of rear arch flue gas recycled injector is lower than face arch flue gas recycled injector, mesh Be to ensure that from scaling spout spray gaseous mixture in uncombusted volatile matter play NOxReduction.
Further, rear arch flue gas recycled injector configuration two rows of nozzles by from smoke evacuation air-introduced machine after recycling Flue gas distinguishes the main burning area below directive segmentation refractory wall and rear arch, while reducing the temperature and oxygen content in coke combustion area, will Reducing zone above grate surface is extended to below front arch secondary air spray head and rear arch Secondary Air spray head, to significantly reduce NOx's It generates, realizes the low nitrogen burning under flue gas classification reducing condition.
Further, flue gas recycled is sprayed from the nozzle of face arch flue gas recycled injector to the aditus laryngis of scaling spout Place overcomes the gas that the flue gas pressures in burner hearth will be pyrolyzed in precombustion chamber and burning generates to be carried along at the aditus laryngis of burner hearth with this And the flue gas recycled sprayed with rear arch flue gas recycled injector carries out NOxReduction burning.
In grate firing boiler system described in the utility model, the First air of other wind cabins feeding in addition to the wind distributing bin that volatilizees A certain amount of vapor that partial recirculation flue gas and steam generator of the middle blending from the outlet of smoke evacuation air-introduced machine generate, then follow Ring flue gas can reduce the oxygen content for being passed through the First air of fire grate, and vapor is on fire grate and red-hot coke generation water-gas is anti- CO and H should be generated2, part gas-solid reaction is converted to gas phase reaction, another aspect CO can increase the reduction zone above coal seam Thickness, and the NO of effectively reduction coal combustion generationx
Further, in order to guarantee transformation after coal seam still be able to abundant after-flame, need to suitably increase and rear arch flue gas recycled Fire grate is corresponding below injector and subsequent each wind cabin matches air quantity, to solve postponement coal seam coke combustion caused by fractional combustion Most problem reduces ash content carbon, and the efficiency of combustion of coal is improved while ensuring low nitrogen burning.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of grate firing boiler described in the example of the utility model.
Fig. 2 is the structural schematic diagram of system described in the example of the utility model.
Fig. 3 is the partial cutaway schematic of wind cabin described in the example of the utility model.
Fig. 4 is the structural schematic diagram for dividing refractory wall described in the example of the utility model.
Fig. 5 is the structural schematic diagram of face arch flue gas recycled injector described in the example of the utility model.
Fig. 6 is the sectional view of the injector of face arch flue gas recycled described in the example of the utility model and scaling spout.
Fig. 7 is the structural schematic diagram of high temperature flue gas ejector described in the example of the utility model.
In figure: 1. face arch, 2. precombustion chambers, 3. face arch flue gas recycled injectors, 4. segmentation refractory walls, the recycling of 5. rear arches Flue gas injection device, 6. burner hearths, 7. rear arches, 8. scaling spouts, 9. volatilization wind distributing bins, 10. conveyer belts, 11. coal gates, 12. face arch Secondary Air spray head, 13. rear arch Secondary Air spray heads, 14. water-cooling wall lower headers, 15. fire grate distribution plenums, 16. high temperature flue gas ejectors, 17. circular hole, 18. grate surfaces, 19. aditus laryngis, 20. segmentation refractory wall lower ends, 21. coal seams, 22. air preheaters, 23. dedusters, 24. air-introduced machine, 25. chimneys, 26. flue gas recycled air-introduced machines, 27. First air air-introduced machines, 28. steam generators, 29. burner hearths two Side wall surface, 30. side walls outside flue, 31. fire grates lower section flue, 32. steel plates, 33. refractory materials, 34. bitch, 35. face arch are again Circulating flue gas injector header, 36. nozzles, 37. nozzle throats, 38. collateral branch pipe, 39. jet pipe contraction sections.
Specific embodiment
The utility model is described in further detail below with reference to specific embodiment, described is to the utility model Explanation rather than limit.
A kind of fuel-air flue gas three of the utility model is classified the grate firing boiler of low nitrogen burning, divides refractory wall 4 for former furnace Thorax space is divided into two, and forms precombustion chamber 2 with face arch 1.Hot fume makes the pyrolysis of coal seam 21 that volatilization be precipitated in volatilization wind distributing bin 9 Point, the radiant heat in burner hearth 6 cooperates with precombustion chamber 2 of igniting with hot fume through gap between segmentation refractory wall bottom end 20 and coal seam 21 In volatile matter, cold water in water-cooling wall lower header 14 during the water screen tube uplink laid along face arch 1 constantly from Precombustion chamber 2 absorbs heat, so that volatile matter be made to burn in the reducing atmosphere of lower temperature, inhibits thermal NOxIt generates.For The needs that grate firing boiler uses different types of coal are adapted to, it can be in conjunction with the component feature of coal, by adjusting opening for coal gate 11 Degree is to change the thickness in coal seam 21, so that the size in gap between segmentation refractory wall bottom end 20 and coal seam 21 is adjusted, it is saturating to guarantee The a small amount of flue gas and radiant heat to come over is enough the lower volatile matter of burning point that ignites, and is unlikely to that coke is made to burn.Precombustion chamber 2 In volatile matter and flue gas further restored at 3 injection to aditus laryngis 19 of face arch flue gas recycled injector because of expanded by heating uplink NOx.Rear arch flue gas recycled injector 5 configures 2 row's nozzle directive main burning areas, reduces main burning area temperature and oxygen content, subtracts Few thermal NOxIt generates, the reducing zone of burner hearth 6 is made to be extended to 13 position of front arch secondary air spray head 12 and rear arch Secondary Air spray head, Strengthen the after-flame of combustible.Except volatilization wind distributing bin 9 other wind cabins First air in be blended with flue gas recycled and vapor, water Steam can occur water gas reaction with coke and generate CO and H2, part gas-solid reaction is converted to gas phase reaction, is increased simultaneously Coal seam 21 and reducing atmosphere thereon.2 volatile matter of precombustion chamber enters in burner hearth from precombustion chamber, after smoke evacuation air-introduced machine 24 again Circulating flue gas is matched from face arch flue gas recycled injector 3, rear arch flue gas recycled injector 5, volatilization wind distributing bin 9 and fire grate respectively Air compartment 15 is sent into burner hearth 6, is expanded the reducing zone of arch lower section before and after original, is greatly inhibited NOxGeneration, the utility model It can make a layer burner NOxRaw emissions are reduced to 100mg/m3Left and right.
The utility model is not changing boiler body pressure element structure, does not add under conditions of large-scale subsidiary engine equipment, leads to The synthesis low-NO_x combustion technology for crossing integrated use fuel staging, air classification and flue gas recycled fractional combustion inhibits from source NOxGeneration, fractional combustion is carried out to fuel by segmentation burner hearth, by air and flue gas recycled cross-fractionation, expands burner hearth The reducing zone of burning reduces the ignition temperature of reduction combustion zone, finally sprays into Secondary Air and carries out fuel after-flame, which can By the original NO of layer burnerxDischarge is reduced to 100mg/m3Left and right, greatly reduces coal-burned industrial boiler SCR/SNCR denitrating flue gas The risk of the investment of transformation, operation cost and secondary pollution caused by implementing due to SCR/SNCR.
Specifically, a kind of fuel-air flue gas three of the utility model is classified the grate firing boiler of low nitrogen burning, including 1 He of face arch Corresponding rear arch 7 and face arch 1 and rear arch 7 surround the burner hearth 6 formed, and burner hearth 6 is divided into two point by segmentation refractory wall 4 It is cut into volatile matter pyrolysis and combustion area and coke combustion zone two parts, coal seam 21 passes through after coal gate 11 above volatilization wind distributing bin 9 Grate surface 18 on by thermal decomposition be precipitated volatile matter.Divide the bottom end that refractory wall lower end 20 is slightly above coal gate 11, in burner hearth 6 Flue gas and radiant heat enter in precombustion chamber 2 through the gap formed between segmentation refractory wall lower end 20 and coal seam 21.Using when need The size in the gap is suitably set the characteristics of coal, according to used in boiler to guarantee to be enough through a small amount of flue gas and radiant heat that come The lower volatile matter of the burning point that ignites, and be unlikely to that coke is made to burn.To guarantee that most of volatile is lower in oxygen content Reducing atmosphere in burn, significantly reduce NOxProduction quantity, realize the fractional combustion of fuel.
Divide and form precombustion chamber 2 between refractory wall 4 and face arch 1, the top of precombustion chamber 2 is equipped with face arch flue gas recycled injection Device 3, effect are sprayed in injection precombustion chamber 2 at uplink flue gas and uncombusted volatile matter to aditus laryngis 19 and with rear arch flue gas recycled The flue gas recycled that emitter 5 sprays carries out NOxReduction burning, most afterwards through upper layer front arch secondary air spray head 12 and rear arch Secondary Air Spray head 13 carries out the further after-flame of Secondary Air, while uncombusted volatile matter can also restore generated part NO in burner hearthx
Rear arch 7 is equipped with rear arch flue gas recycled injector 5 at aditus laryngis 19, and a row is arranged in secondary furnace at aditus laryngis 19 The lower section of front arch secondary air spray head 12 and row's rear arch Secondary Air spray head 13, conveyer belt 10 is equipped with fire grate distribution plenum 15, close The hearth biside wall face 29 of segmentation refractory wall 4 opens up circular hole 17 respectively, and the part high-temperature flue gas in burner hearth 6 passes through cigarette outside side wall Road 30 flow to high temperature flue gas ejector 16.
The high temperature flue gas ejector 16 draws using from 26 exit low temperature flue gas recycled of flue gas recycled air-introduced machine It penetrates part furnace high-temperature flue gas and sprays mixed hot fume to the grate surface 18 of 9 top of volatilization wind distributing bin, effect It is to ignite and heat is provided for the pyrolysis of coal seam 21 and volatile matter, and the temperature in coal seam 21 is not caused to reach coke burning point and make coke Burning.
The hearth biside wall face 29 opens up circular hole 17, and circular hole 17 opens up position and should suitably raise as close as possible to burner hearth 6 reducing zone, but front arch secondary air spray head 12 and rear arch Secondary Air spray head 13 must not be higher than.Part high-temperature flue gas in burner hearth 6 It is flow at the aditus laryngis of high temperature flue gas ejector 16 along flue 30 outside side wall, then by low temperature flue gas recycled injection, mixing Hot fume afterwards is flow at the grate surface 18 above volatile matter wind cabin 9 after spraying along flue, and the pyrolysis for coal seam 21 provides heat, The volatile matter that the pyrolysis of coal seam 21 generates is divided the radiation thermal ignition after-combustion between refractory wall lower end 20 and coal seam 21, flue gas by It is advanced into thermal expansion in precombustion chamber 2.
The precombustion chamber 2 is provided with face arch flue gas recycled injector 3 at aditus laryngis 19, i.e., sets at the aditus laryngis of face arch 1 It is equipped with face arch flue gas recycled injector 3, the rear arch 7 is provided with rear arch flue gas recycled injector 5, face arch at aditus laryngis The mounting height of flue gas recycled injector 3 is higher than rear arch flue gas recycled injector 5.To ensure face arch flue gas recycled injection The NO for the volatile matter that device 3 spraysxReduction, the main function of face arch flue gas recycled injector 3 are the cigarettes overcome in burner hearth 6 Atmospheric pressure will be pyrolyzed in precombustion chamber 2 and the gas generated that burns is carried along into burner hearth 6.
The face arch flue gas recycled injector 3 is disposed with jet pipe 36 of the row towards aditus laryngis 19.
After the rear arch flue gas recycled injector 5 is disposed with jet pipe and the row direction of row direction segmentation refractory wall 4 Encircle the jet pipe in 7 underface main burning areas.Wind cabin corresponding and subsequent each with 5 lower section fire grate of rear arch flue gas recycled injector It need to suitably be increased with air quantity, reduce by 21 coke of coal seam on caused fire grate to solve First air and flue gas recycled oxygen content and postpone The problem of after-flame reduces ash content carbon, and the efficiency of combustion of coal is improved while ensuring low nitrogen burning.
The face arch flue gas recycled injector 3 utilizes the flue gas recycled from 26 exit of flue gas recycled air-introduced machine The volatile matter of uplink after injection coal seam 21 is pyrolyzed, volatile matter, which is admitted at aditus laryngis 19, to burn.
The rear arch flue gas recycled injector 5 comes from and draws to segmentation refractory wall 4 and the injection of 7 underface main burning area of rear arch Flue gas recycled after blower 24.Low temperature flue gas recycled after air-introduced machine 24 is first in face arch flue gas recycled injector collection Collect in case 35, then is scaled at the top of from the injection of jet pipe 36 to segmentation refractory wall 4 from the aditus laryngis of spout 8, the high speed gas ejected Stream will be at the volatile matter injection to aditus laryngis 19 in precombustion chamber 2.
Deposited refractory material 33 is made after the segmentation refractory wall 4 welds bitch 34 by 32 two sides of steel plate.The segmentation fire resisting 4 top of wall opens up scaling spout 8, and scaling spout 8 is the conduit that a section is de Laval noz(zle).The segmentation refractory wall bottom end 20 Lower end than coal gate 11 is slightly higher.
The front arch secondary air spray head 12 and the horizontally-opposed injection Secondary Air of rear arch Secondary Air spray head 13 are with combustion-supporting aditus laryngis 19 The volatile matter at place strengthens the disturbance of flue gas in burner hearth 6.
Blending comes from and draws in the First air that the fire grate distribution plenum 15 is sent into other wind cabins in addition to the wind distributing bin 9 that volatilizees A certain amount of vapor that partial recirculation flue gas and steam generator 28 after blower 24 generate.
In this preferred embodiment, as shown in Figure 1, a kind of fuel-air flue gas three of the utility model is classified the layer combustion of low nitrogen burning Boiler, including face arch 1 and rear arch 7 form precombustion chamber 2 between the face arch 1 and segmentation refractory wall 4, divide refractory wall 4 by steel plate 32 Refractory material 33 is applied after two sides welding bitch 34 to be made, and is divided refractory wall 4 for burner hearth 6 and is divided into volatile matter pyrolysis and combustion section and coke Charcoal combustion zone two parts, coal seam 21 are thermally decomposed to generate on the grate surface 18 above volatilization wind distributing bin 9 after passing through coal gate 11 Volatile matter.Since segmentation refractory wall lower end 20 is slightly above the bottom end of coal gate 11, segmentation refractory wall lower end 20 and coal seam 21 Between will form a lesser gap, the flue gas and radiant heat in burner hearth 6 can enter in precombustion chamber 2 through the gap. According to used in boiler the characteristics of coal, the size in the gap need to be suitably set, to guarantee through a small amount of flue gas and radiant heat come It is enough the lower volatile matter of burning point that ignites, and is unlikely to that coke is made to burn.Most of volatile is lower also in oxygen content It burns in originality atmosphere, to significantly reduce the NO as caused by volatile matter nitrogenxYield.
As shown in figure 4, face arch flue gas recycled injector 3 is equipped at the upper outlet of precombustion chamber 2, in segmentation fire resisting The top of wall 4 opens up scaling spout 8, and scaling spout 8 is the conduit that a section is de Laval noz(zle).Portion after air-introduced machine 24 Divide flue gas recycled to spray from the nozzle of face arch flue gas recycled injector 3 to from the aditus laryngis of scaling spout 8, burner hearth is overcome with this Flue gas pressures in 6 will be pyrolyzed in precombustion chamber 2 and the gas generated that burns is carried along at the aditus laryngis 19 of burner hearth 6 and with rear arch again The flue gas recycled that circulating flue gas injector 5 sprays carries out NOxReduction burning, the most front arch secondary air spray head 12 through upper layer afterwards The further burning of Secondary Air is carried out, with rear arch Secondary Air spray head 13 to ensure the completely burned off of volatile matter.
As shown in figure 3, being 2. high-temperature flue gas;3. being flue gas recycled;4. being the mixing of high-temperature flue gas and flue gas recycled Gas, as mixed hot fume;The partial recirculation cigarette after air-introduced machine 24 is passed through in the flue of 9 lower section of volatilization wind distributing bin Gas offers circular hole 17 in the burner hearth two sides side wall 29 close to segmentation refractory wall 4, for the oxygen content for guaranteeing institute's injection high-temperature flue gas As low as possible, should suitably raise circular hole 17 opens up position, with the reducing zone as close as possible to burner hearth 6, but must not be higher than face arch two Secondary wind spray head 12 and rear arch Secondary Air spray head 13.A part of high-temperature flue gas in burner hearth 6 flow to height along flue 30 outside side wall At the aditus laryngis of warm flue gas ejector 16, it is then recycled flue gas injection, mixed hot fume flow to along flue after spraying and waves At the grate surface 18 for sending out the top of wind distributing bin 9, effect is not to provide heat for the pyrolysis in coal seam 21 and igniting for volatile matter, and not The temperature in coal seam 21 is caused to reach coke burning point and coke is caused to burn.
2. the structure of high temperature flue gas ejector 16 is as shown in fig. 7, be ejection gas, that is, high-temperature flue gas;3. being for incident gas Flue gas recycled;4. for the gaseous mixture of injection gas, that is, flue gas recycled and high-temperature flue gas;High-temperature flue gas is flowed by collateral branch's pipe High temperature flue gas ejector 16, flue gas recycled accelerate during flowing through jet pipe contraction section 39, thus in 37 shape of nozzle throat At low-pressure area, to achieve the purpose that attract the high-temperature flue gas downlink in collateral branch's pipe 38.The gaseous mixture of volatile matter and flue gas is in pre-burning It is heated in room 2 and sharply expands, later by 3 injection of face arch flue gas recycled injector on 2 top of precombustion chamber to 6 top of burner hearth In secondary furnace at the position of aditus laryngis 19, uncombusted volatile matter carries out NO hereinxReduction burning.It is leaned in the rear arch 7 Rear arch flue gas recycled injector 5 is equipped at nearly aditus laryngis, height is lower than the height of face arch flue gas recycled injector 3, with true It protects the volatile matter that face arch flue gas recycled injector 3 sprays and plays NOxReduction.
The task of face arch flue gas recycled injector 3 is to make uncombusted volatile matter such as hydro carbons, H2Equal fuel gas are in larynx It burns in low excess air coefficient region at mouth 19, can both reduce the NO of volatile combustion generationx, and can reduce The excess air coefficient of coke combustion zone in boiler furnace 6 is conducive to create large range of reducing zone, promote in combustion process The NO of generationxIt is reduced into N2, it may also be ensured that volatile matter is completely burned off, guarantee the fuel utilization efficiency of boiler.If transformation after still without Method makes NOxDischarge is reduced to standard level, can also mix in the flue gas recycled for being passed through volatilization wind distributing bin 9 a certain amount of Ammonia, to further decrease NOxEmission level.The structure and working principle of face arch flue gas recycled injector 3 respectively such as Fig. 5 and It is 3. injection gas, i.e. flue gas recycled shown in Fig. 6;5. the mixed of volatile matter and hot fume is precipitated in the pyrolysis of ejection gas, i.e. coal seam Close gas;In grate firing boiler system as shown in Figure 2, the low temperature flue gas recycled exported from flue gas recycled air-introduced machine 26 collects It is pre- with this injection by the injection of each nozzle 36 to the aditus laryngis for scaling spout 8 after to face arch flue gas recycled injector header 35 The volatile matter of uplink and the gaseous mixture of hot fume in room 2 is fired to arrive at aditus laryngis 19 by scaling spout 8 and recycle cigarette with rear arch The flue gas recycled that gas blowout emitter 5 sprays carries out NOxReduction burning.As shown in fig. 6, scaling 8 left of spout is precombustion chamber 2, Right is burner hearth 6.As shown in Fig. 2, being 1. First air, First air is after First air air-introduced machine enters in air preheater 22 and preheats Connect steam generator 28, in addition to point storehouse 9 with for other point of storehouse water vapour is provided.
Flue gas recycled after two rows of self-induced-air machines in nozzle future 24 that rear arch flue gas recycled injector 5 configures is penetrated respectively Coke combustion zone to below segmentation refractory wall 4 and rear arch, while the ignition temperature and oxygen content in coke combustion area are reduced, by fire grate The reducing zone of 18 top of face is extended to the lower section of front arch secondary air spray head 12 and rear arch Secondary Air spray head 13, significantly reduces NOx's It generates, realizes the low nitrogen burning under flue gas classification reducing condition.Between two rows of nozzles that rear arch flue gas recycled injector 5 configures Angle can be adjusted between 1 °~120 ° according to coal situation, can also be fixed in a certain angle.
Blending goes out from flue gas recycled air-introduced machine 26 in the First air that other wind cabins in addition to the wind distributing bin 9 that volatilizees are sent into A certain amount of vapor that the partial recirculation flue gas and steam generator 28 of mouth generate, flue gas recycled can reduce and be passed through furnace The oxygen content of the First air of row, vapor occur water gas reaction and generate CO and H on fire grate with red-hot coke2, by part Gas-solid reaction is converted to gas phase reaction, and another aspect CO can increase the reduction zone thickness of 21 top of coal seam, and effective reduction coal The NO that 21 burning of layer generatesx
Due to setting up for precombustion chamber 2, divide the face arch that refractory wall 4 acts as coal seam 21 of igniting, the combustion process in coal seam 21 It is postponed, is equivalent to the effective length for shortening grate surface 18.In order to guarantee that coal seam 21 still is able to abundant after-flame after transformation, need to fit Match air quantity when increasing wind cabin corresponding and subsequent each with 5 lower section fire grate of rear arch flue gas recycled injector, to solve to be classified The problem that 21 coke after-flame of coal seam is postponed caused by burning, reduces ash content carbon, coal is improved while ensuring low nitrogen burning The efficiency of combustion of charcoal.
Front arch secondary air spray head 12 and the opposed injection Secondary Air of rear arch Secondary Air spray head 13 are to strengthen the after-flame of combustible, institute State front arch secondary air spray head 12 and rear arch Secondary Air spray head 13 angle can according to coal-fired type on the basis of by level- The adjusting of 15 °~45 ° progress injection directions, to realize Researched of Air Staging Combustion Burning Pulverized Coal.
The working principle of the utility model are as follows: former furnace cavity is divided into two by segmentation refractory wall 4, and between face arch 1 A precombustion chamber 2 is formed, the hot fume of uplink is given from coal lock in the heating power preparation stage of layer combustion chain-grate boiler, volatilization wind distributing bin 9 The pyrolysis of coal seam 21 and igniting for volatile matter that door is sent into provide heat, and a small amount of flue gas and radiant heat are resistance to through dividing in burner hearth 6 The gap formed between wall with flues lower end 20 and coal seam 21 enters in precombustion chamber 2, cooperates with the burning point that ignites lower with the hot fume of uplink Volatile matter so that most of volatile is burnt in the lower reducing atmosphere of oxygen content, and be unlikely to send out coke Raw burning, uncombusted volatile matter are then carried the top for going upward to precombustion chamber 2 by flue gas, go out from flue gas recycled air-introduced machine 26 Mouthful low temperature flue gas recycled will volatilize point with the gaseous mixture of flue gas by face arch flue gas recycled injector 3 from precombustion chamber injection To aditus laryngis 19, uncombusted volatile matter is in the secondary furnace above burner hearth 6 close to the area of the low excess air coefficient of aditus laryngis 19 Reduction burning is carried out in domain, to be further reduced NO during volatile combustionxProduction quantity, guarantee the complete combustion of volatile matter It burns, while the NO carried from the high-temperature flue gas from 6 aditus laryngis 19 of burner hearthxIt is reduced into N2.Front arch secondary air spray head 12 and rear arch two The opposed Secondary Air that sprays of secondary wind spray head 13 realizes the fractional combustion of air to strengthen the after-flame of combustible.Rear arch flue gas recycled Main burning area immediately below the two rows of nozzles difference directive segmentation refractory wall 4 and rear arch that injector 5 configures, can reduce coke simultaneously The reducing zone of 18 top of grate surface is extended to front arch secondary air spray head 12 and rear arch two by the ignition temperature and oxygen content of combustion zone The lower section of secondary wind spray head 13 significantly reduces NOxGeneration, realize flue gas classification reducing condition under low nitrogen burning.Due to pre-burning Room 2 is set up, and segmentation refractory wall 4 acts as the face arch in coal seam 21 of igniting, and the combustion process in coal seam 21 is postponed, and is equivalent to shortening The effective length of grate surface 18.In order to guarantee that coal seam 21 still is able to abundant after-flame after transformation, need to suitably increase and follow again with rear arch 5 lower section fire grate of ring flue gas injection device is corresponding and subsequent each wind cabin matches air quantity, to solve to postpone coal caused by fractional combustion The problem of 21 coke after-flame of layer, reduces ash content carbon, and the efficiency of combustion of coal is improved while ensuring low nitrogen burning.Except waving It blends in the First air that other wind cabins except hair wind distributing bin 9 are sent into and is followed again from the part that flue gas recycled air-introduced machine 26 exports A certain amount of vapor that ring flue gas and steam generator 28 generate, flue gas recycled can reduce the First air for being passed through fire grate Oxygen content, vapor occur water gas reaction and generate CO and H on fire grate with red-hot coke2, part gas-solid reaction is converted At gas phase reaction, another aspect CO can increase the reduction zone thickness of 21 top of coal seam, and effectively the burning of reduction coal seam 21 generates NOx.2 volatile matter of precombustion chamber enters in burner hearth from precombustion chamber, and the flue gas recycled difference after smoke evacuation air-introduced machine 24 is in the past Encircle flue gas recycled injector 3, rear arch flue gas recycled injector 5, volatilization wind distributing bin 9 and fire grate distribution plenum 15 and is sent into burner hearth 6 In, the excess air coefficient in furnace is greatly reduced, vast reducing zone is created in furnace, considerably reduces NOxRow It puts.

Claims (9)

1. the grate firing boiler that a kind of fuel-air flue gas three is classified low nitrogen burning, which is characterized in that including face arch (1) and right therewith Burner hearth (6), aditus laryngis (19) and the combustion chamber that the rear arch (7) answered, face arch (1) and rear arch (7) sequentially form from top to bottom, Yi Jilu Conveyer belt (10) below thorax (6);
The segmentation refractory wall (4) to break it into two, segmentation refractory wall (4) and face arch (1) shape are provided in the burner hearth (6) It is used as volatile matter pyrolysis and combustion area at precombustion chamber (2), segmentation refractory wall (4) and rear arch (7) form coke combustion zone;Divide fire resisting Gap is formed between coal seam (21) on wall lower end (20) and conveyer belt (10), for through in burner hearth (6) interior coke combustion zone Flue gas and radiant heat so that the volatile combustion and coke in precombustion chamber (2) do not burn;
The top of the precombustion chamber (2) is equipped with the face arch flue gas recycled injector (3) for being located at segmentation refractory wall (4), and face arch is again Circulating flue gas injector (3) be used for by precombustion chamber (2) uplink flue gas and uncombusted volatile matter be injection to aditus laryngis (19);
The rear arch (7) is equipped with rear arch flue gas recycled injector (5) at aditus laryngis (19), and secondary furnace is at aditus laryngis (19) Front arch secondary air spray head (12) and rear arch Secondary Air spray head (13) are set.
2. the grate firing boiler that a kind of fuel-air flue gas three according to claim 1 is classified low nitrogen burning, which is characterized in that Several wind cabins corresponding with its top coal seam are provided with below the conveyer belt (10), it is corresponding with pyrolysis and combustion area for volatilization Wind distributing bin (9), volatilization wind distributing bin (9) is interior to be symmetrically arranged with high temperature flue gas ejector (16);It is resistance to close to dividing in coke combustion zone The hearth biside wall face (29) of wall with flues (4) opens up circular hole (17) respectively, and the part high-temperature flue gas in burner hearth (6) passes through outside side wall Flue (30) is flow to high temperature flue gas ejector (16), and high-temperature flue gas is drawn by the flue gas recycled for being passed through high temperature flue gas ejector (16) The grate surface (18) being incident upon above volatilization wind distributing bin (9).
3. the grate firing boiler that a kind of fuel-air flue gas three according to claim 2 is classified low nitrogen burning, which is characterized in that The position that the hearth biside wall face (29) opens up circular hole (17) should be close to the reducing zone of burner hearth (6), and is not higher than front arch secondary Wind spray head (12) and rear arch Secondary Air spray head (13).
4. the grate firing boiler that a kind of fuel-air flue gas three according to claim 1 is classified low nitrogen burning, which is characterized in that Secondary furnace horizontally-opposed row front arch secondary air spray head (12) and row's rear arch Secondary Air spray head (13) at aditus laryngis (19);Institute The angle for stating front arch secondary air spray head (12) and rear arch Secondary Air spray head (13) can be carried out by -15 ° on the basis of level~45 ° The adjusting of injection direction.
5. the grate firing boiler that a kind of fuel-air flue gas three according to claim 1 is classified low nitrogen burning, which is characterized in that The mounting height of the face arch flue gas recycled injector (3) is higher than rear arch flue gas recycled injector (5).
6. the grate firing boiler that a kind of fuel-air flue gas three according to claim 1 is classified low nitrogen burning, which is characterized in that Face arch flue gas recycled injector (3) is disposed with jet pipe (36) of the row towards aditus laryngis (19);Rear arch flue gas recycled injector (5) be disposed with a row towards segmentation refractory wall (4) jet pipe and a row towards coke combustion zone below rear arch (7) jet pipe, two The angle arranged between nozzle is 1 °~120 °.
7. the grate firing boiler that a kind of fuel-air flue gas three according to claim 1 is classified low nitrogen burning, which is characterized in that The segmentation refractory wall (4) is applied refractory material (33) by steel plate (32) two sides welding bitch (34) afterwards and is made;Divide refractory wall (4) Top opens up scaling spout (8), and scaling spout (8) is the conduit that a section is de Laval noz(zle), face arch flue gas recycled injection The nozzle of device (3) is set at the aditus laryngis of scaling spout (8).
8. the grate firing boiler system that a kind of fuel-air flue gas three is classified low nitrogen burning, which is characterized in that including such as claim Grate firing boiler described in 1-7 any one is connected to hot end, the deduster of the air preheater (22) of grate firing boiler flue in turn (23), air-introduced machine (24) and chimney (25);
Flue between the air-introduced machine (24) and chimney (25) is provided with flue gas recycled pipeline, in circulating flue gas pipeline through again Circulating flue gas air-introduced machine (26) be respectively connected to face arch flue gas recycled injector (3), rear arch flue gas recycled injector (5) and High temperature flue gas ejector (16);
The lower section of the conveyer belt (10) is equipped with fire grate distribution plenum (15), and the output end of fire grate distribution plenum (15), which is separately connected, to be removed Other wind cabins other than volatilization wind distributing bin (9);
First air successively connects fire grate through First air air-introduced machine (27), the cold end of air preheater (22) and steam generator (28) The input terminal of distribution plenum (15).
9. a kind of fuel-air flue gas three according to claim 8 is classified the grate firing boiler system of low nitrogen burning, feature It is, fire grate is corresponding when fire grate distribution plenum (15) air distribution, below rear arch flue gas recycled injector (5) and subsequent each wind cabin Be greater than remaining each wind cabin air quantity with air quantity.
CN201821748919.9U 2018-10-26 2018-10-26 A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning Active CN209371229U (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109297014A (en) * 2018-10-26 2019-02-01 西安交通大学 A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning
CN117231987A (en) * 2023-11-14 2023-12-15 光大环境科技(中国)有限公司 Deep low-nitrogen combustion air distribution system suitable for garbage incinerator
CN109297014B (en) * 2018-10-26 2024-10-25 西安交通大学 Layered combustion boiler for fuel air flue gas three-stage low-nitrogen combustion and system thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109297014A (en) * 2018-10-26 2019-02-01 西安交通大学 A kind of fuel-air flue gas three is classified the grate firing boiler and its system of low nitrogen burning
CN109297014B (en) * 2018-10-26 2024-10-25 西安交通大学 Layered combustion boiler for fuel air flue gas three-stage low-nitrogen combustion and system thereof
CN117231987A (en) * 2023-11-14 2023-12-15 光大环境科技(中国)有限公司 Deep low-nitrogen combustion air distribution system suitable for garbage incinerator
CN117231987B (en) * 2023-11-14 2024-03-26 光大环境科技(中国)有限公司 Deep low-nitrogen combustion air distribution system suitable for garbage incinerator

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