Nonflame low NO and nonflame low nitrogen burning methodTechnical field
The invention belongs to industrial burners and field of boilers, and in particular to nonflame low NO and nonflame low nitrogen burning sideMethod is mainly used for industrial burner and boiler.
Background technique
Combustion of industrial boiler device mostly uses the combustion system of traditional, forced air supply, diffusion type, the master of the type burnerSyllabus is after-flame and safety, and few pairs of NOx emissions do corresponding measure.Now, for some area 30mg/m3Following NOxThe environmental requirement of discharge, has already appeared and adopted main technological route includes that disperses combustion, premixed combustion, flue gas follow againRing, porous media catalysis burning and flameless combustion:
(1) fuel disperses combustion or air disperses combustion
Two methods will eventually make the excess air coefficient of whole system keep a definite value.The technological system is more multipleIt is miscellaneous, and also without the high-temperature area of elimination flame.
(2) lean premixed combustion technology
The advantages of generation for control NOx, this technology is can to fully control realization to burning by equivalent proportionThe control of temperature, to reduce thermal NO x generating rate, in some cases, premixed combustion and partly-premixed than non-pre-The NOx that mixed burning reduces 85% -90% is generated.In addition, fully premixed can also be reduced because of excess air coefficient inhomogeneities instituteThe caused reduction that control is generated to NOx.If lean combustion premix is again plus wire mesh combustion head, surface burning is formed, then flame is moreFor dispersion, NOx emission is further decreased.
But premixed combustion technology safety control on there are still unsolved technological difficulties: first is that premixed gas byIt may result in tempering in its high flammability；Second is that excessively high excess air coefficient will lead to the increase of flue gas loss, reduceBoiler thermal efficiency；Third is that wire mesh combustion head is easy the fine dust being melted adherency, maintenance period is short.Lean combustion nowPremix burner power is usually no more than 2MW
(3) external flue gas recirculation and inside smoke recirculating technique
The reduction of ignition temperature can realize that the flue gas heat absorption of addition is to reduce by the way that flue gas is added in flame regionIgnition temperature.By the way that the combustion product of flue gas to be added in combustion zone, ignition temperature is not only reduced, NOx is reducedIt generates；The flue gas being added simultaneously reduces the partial pressure of oxygen, this will weaken oxygen and nitrogen generates the process of thermal NO x, fromAnd reduce the generation of NOx.According to the difference of application principle, there are two types of application modes for flue gas recirculation, and respectively external flue gas is againCirculation is recycled with inside smoke.
For external flue gas recirculating technique, flue gas, by an external pipe, is rejoined from the outlet of boilerInto burner hearth.The NOx that external flue gas recirculation can reduce 70% is generated.Outer circulation ratio also has NOx control effect largerIt influences, as the increase NOx reduction amplitude of outer circulation ratio is also more obvious, but circulating fan power consumption will also increase.
Inside smoke is recycled, smoke backflow to combustion zone mainly passes through the aerodynamics of burner.It is internalFlue gas recirculation mainly passes through the Involving velocity of high speed jet flames or turbulent burner is rotated up to air-flow generation to followRing effect.By generating an annular recirculation regions in flame kernel, high-temperature gas will be returned to burner throat, this ensuresIgniting to cold unburned gas, while reducing NOx by reducing flame temperature and reducing oxygen partial pressure and generate.
(4) porous media catalysis burning
Another method for reducing flame temperature is exactly the external heat transfer of as fast as possible and more reinforcement flame.In burnerPorous media (PIM) is inside increased, so that the spoke in porous media, in this way from burner to ambient enviroment occurs for combustion reactionIt penetrates and is just reinforced with heat convection.Experiment shows that using the ignition temperature of PIM burner, NOx generation amount exists lower than 1600K5-20ppm or so.
PIM burner can also add catalyst at burner inlet, and such fuel molecule and oxidizer molecule willIt is reacted with a relatively low activation energy in catalyst surface.Reaction temperature in this way is lower compared to similar burning.Since reaction process is only carried out in catalyst surface, NOx will not be generated, the NOx generation of catalysis burning in this way can be down to 1ppm.
The shortcomings that catalysis burning is exactly that must assure that active surface is not oxidized at a temperature of one is relatively low or evaporation,And catalyst cost is relatively high, there are intoxicating phenomenons for catalyst prolonged application, therefore such burner is difficult to be answered on a large scaleWith.
(5) flameless combustion
Traditional flame combustion is divided into premixed combustion and diffusion combustion, main feature include: 1. fuel and oxygen in heightThe lower reaction of temperature, the temperature the high more facilitates the stabilization of flame；2. flame front face it is visual (flame of methyl hydride combustion is generally blue,It is yellow when having soot generation)；3. most of fuel complete burning in the very thin zone of flame, but combustion reaction can be in downstreamSightless region in complete.
Under normal circumstances, flame generally oneself serves as igniter after lighting, and lights a fire to incoming flow.This just needs footHigh flame temperature is reached to reach minimum ignition energy, but high flame temperature, which can make NOx generate, to be increased.
Someone is 1000 DEG C, under air preheat to 650 DEG C, the higher situation of air-flow velocity in in-furnace temperature, realizes combustionExpect flameless combustion.Also someone utilizes the position between the annular main combustion nozzle being evenly arranged and the tubular return-flow structure of center arrangementThe shearing effect of relationship and viscous fluid, forms a large amount of reflux high-temperature flue gas and fresh air blends, and improves the temperature of airIt spends and air is diluted, which encounters fuel and spontaneous combustion occurs, high degree of dispersion reaction zone is formed, fromAnd realize flameless combustion.For such flameless combustion, smoke backflow occurs before combustion, in some instances it may even be possible in burning,The fuel and air of the flue gas that recycles in this way premix, and ignition temperature is reduced, expand conversion zone.Nonflame combustionThe flame that makes a fire is evenly distributed, and ignition temperature is low, and it is less that this generates NOx.It is empty that such flameless combustion generally requires special preheatingThe device of gas or measure.
Summary of the invention
In order to solve the problems, such as that fuel gas buring NOx emission is higher, present inventor has performed sharp studies, design a kind of nothingFlame low NO and nonflame low nitrogen burning method, NOx emission meet low emission requirement, and fuel disperses combustion or sky may be not presentGas disperses combustion, lean premixed combustion technology, external flue gas recirculation and inside smoke recirculating technique, porous media catalysis combustionIt burns, limitation possessed by flameless combustion, thereby completing the present invention.
Invention is designed to provide following technical scheme:
(1) a kind of nonflame low NO, the burner include air hose system and fuel gas conduit system, and air hose system includesIt participates in surrounding the air duct 1 of mixing chamber and protrudes into the air hose in mixing chamber, fuel gas conduit system includes the fuel gas conduit protruded into mixing chamber；
Air hose introduces air, and fuel gas conduit introduces combustion gas, and air and fuel gas high-speed mix and be mixed intracavitary high-temperature flue gasAfter heating and dilution, burn.
(2) a kind of nonflame low nitrogen burning method is implemented, this method packet by nonflame low NO described in above-mentioned (1)Including moves toward one another combustion gas with high temperature and high speed air, and burns after being diluted by high-temperature flue gas.
The nonflame low NO and nonflame low nitrogen burning method provided according to the present invention, has the advantages that
It (1) include multiple air hoses and fuel gas conduit, spray orifice of arranging on air hose and fuel gas conduit, air hose in mixing chamber in the present inventionStaggered with fuel gas conduit layering, by more nozzle hole number and biggish jet surface product, combustion gas and air be can be realizedIt is sufficiently mixed in a very short period of time；
(2) in the present invention, air duct is sandwich, and interlayer is realized in the heat transfer that can efficiently use high-temperature flue gas in mixing chamberThe preliminary preheating of middle air reduces the heat loss of flue gas, and is conducive to the raising of efficiency of combustion；
(3) in the present invention, the classification arrangement of air hose and fuel gas conduit and fuel gas conduit at different levels and/or air hose at different levels, periphery are firedThe setting that the arrangement shape of tracheae and/or periphery air hose matches with the cross sectional shape of mixing chamber is conducive to improve combustion uniformityAnd stability.
(4) in the present invention, by the arrangement of air hose and fuel gas conduit, conducive to straight by the different spray orifice of control different zonesDiameter realizes that air feed and combustion gas different ratio further decrease the discharge of nitrogen oxides to form fractional combustion.
(5) in the present invention, multiple groups air hose and fuel gas conduit with several spurt holes improve the mixing of burning with air,One flame is divided into several flammules, and the thickness of flame front is thinned, and heat dissipation area increases, and flame temperature reduces, while burningIn the case that load is constant, flammule face shortens the residence time of oxygen, nitrogen in flame front i.e. high-temperature region.In addition, multiple spot clothThe mode for setting disperses combustion, avoid calorific intensity concentration of local, and the disperse nucleus of flame of high-temperature region, flame region temperature are more equalEven, the above favorable factor has apparent inhibiting effect to " thermal NO x " and " fuel type NOx ".
Detailed description of the invention
Fig. 1 shows a kind of structural schematic diagram of the nonflame low NO of preferred embodiment according to the present invention；
Fig. 2 shows a kind of side sectional views of the nonflame low NO of preferred embodiment according to the present invention；
Fig. 3 shows a kind of side sectional view of the periphery air hose of preferred embodiment according to the present invention；
Fig. 4 shows a kind of side sectional view of the level-one air hose of preferred embodiment according to the present invention；
Fig. 5 shows a kind of sectional view of preferred embodiment according to the present invention.
Drawing reference numeral explanation:
1- air duct；
2- side plate；
The center 31- fuel gas conduit；
The periphery 32- fuel gas conduit；
41- level-one air hose；
The periphery 42- air hose；
5- gas manifold；
6- mounting hole I；
7- mounting hole II.
Specific embodiment
Below by drawings and examples, the present invention is described in more detail.Illustrated by these, the features of the present inventionIt will be become more apparent from advantage clear.
Dedicated word " exemplary " means " being used as example, embodiment or illustrative " herein.Here as " exemplary "Illustrated any embodiment should not necessarily be construed as preferred or advantageous over other embodiments.
As depicted in figs. 1 and 2, the present invention provides a kind of nonflame low NO, the burner includes air hose systemWith fuel gas conduit system, air hose system includes participating in surrounding the air duct 1 of mixing chamber and protruding into the air hose in mixing chamber, fuel gas conduit systemIncluding protruding into the fuel gas conduit in mixing chamber；
With several air jet orifices to spray the air for having setting pressure on air hose tube wall, if being arranged on combustion gas tube wallDry gas jet orifice has the combustion gas of setting pressure to spray, and air and fuel gas high-speed mix and are mixed intracavitary high-temperature flue gas and addAfter heat and dilution, burn.
In a preferred embodiment, mixing chamber is the generation air-gas or combustion gas-that side plate 2 and air duct 1 surroundThe place of air-flue gas mixing and fuel gas buring.The fuel gas conduit and air hose pass through side plate 2 and enter mixing chamber, and side plate 2 is rightFuel gas conduit and air hose are played a supporting role.
In a preferred embodiment, air duct 1 can be cylinder, section be regular polygon cylinder, section is not adviseThen polygon cylinder etc. can be divided into along its axially symmetric structure cylinder or along its axial unsymmetric structure cylinder, preferably along itAxially symmetric structure cylinder, more preferably cylinder, axial direction are its length direction.
Air duct 1 is sandwich, is connected with air in interlayer, outer layer wall surface not apertured, the internal layer wall surface in mixing chamberUpper setting annular air spray orifice, air can spray into mixing chamber by the air jet orifices on 1 internal layer wall surface of air duct and participate in burning.
When combustion gas is lighted and burner operates normally, first high speed rolls up the flue gas around inhaling, the combustion after dilution for the combustion gas of injectionThe high temperature and high speed air that gas and same volume have inhaled flue gas moves toward one another, is sufficiently mixed and burns.The combustion gas of high speed ejection is inhaled because of volumeFlue gas, gas concentration are diluted.The air of high speed ejection is because volume has inhaled flue gas, and oxygen concentration is diluted, combustion reactionIt is slack-off.The internal layer wall surface of air duct 1 forms the condition of high temperature because heated, is tentatively preheated to the air in air duct 1.Sky after ejectionGas is able to further heat temperature raising because volume inhales high-temperature flue gas.The air smoke mixture of high temperature, the air-flow of high speed and slower combustionReaction is burnt, will form disperse formula flameless combustion, burn seedless heart district and high-temperature region, thermal NO x and Quick-type NOx generation subtractIt is few.
In a kind of preferred embodiment of the present invention, air hose be it is multiple, fuel gas conduit is multiple, air hose and fuel gas conduit layeringIt is staggered.In this way, combustion gas and air mixing are more effective by more nozzle hole number and biggish jet surface product.
It is the pipe of regular polygon, pipe that section is irregular polygon etc. that fuel gas conduit and air hose, which can be round tube, section,It can be divided into along its axially symmetric pipe or along its axial asymmetrical pipe, preferably along its axially symmetric pipe, more preferablyRound tube.
In further preferred embodiment, fuel gas conduit includes the center fuel gas conduit 31, close positioned at mixing chamber centerThe periphery fuel gas conduit 32 of 1 inner wall of air duct and the combustions at different levels optionally between center fuel gas conduit 31 and periphery fuel gas conduit 32Tracheae.In center fuel gas conduit 31 to the direction of periphery fuel gas conduit 32, fuel gas conduit is named as level-one fuel gas conduit, second gas burningPipe ..., N grades of fuel gas conduits, N is positive integer, with level-one combustion gas distance center fuel gas conduit 31 be equidistant or it is extremely close.
Air hose include the level-one air hose 41 for surrounding center fuel gas conduit 31, close to 1 inner wall of air duct periphery air hose 42 and optionallyOther air hoses at different levels of ground between level-one air hose 41 and periphery air hose 42.At center, fuel gas conduit 31 is to the side of periphery air hose 42Upwards, air hose be named as level-one air hose 41, second level air hose ..., N grades of air hoses, N is positive integer, with level-one air hose distance centerFuel gas conduit 31 be equidistant or it is extremely close.
In embodiment still more preferably, fuel gas conduits at different levels and/or air hose at different levels and periphery fuel gas conduit 32And/or the arrangement shape of periphery air hose 42 matches with the cross sectional shape of mixing chamber, to improve combustion uniformity and stability.
In embodiment still more preferably, as shown in Figure 1, side plate 2 is circle, air duct 1 is cylindrical shape, i.e., it is enclosedAt the cross section of mixing chamber be circle, fuel gas conduit and air hose are staggered with annular shape layering in air duct 1.Fuel gas conduit includesCenter fuel gas conduit 31 and periphery fuel gas conduit 32 positioned at mixing chamber center, air hose include the level-one air hose for surrounding center fuel gas conduit 3141 and the periphery of periphery fuel gas conduit 32 periphery air hose 42.
Preferably, the number of center fuel gas conduit 31 is one, and the number of level-one air hose 41 is six, periphery fuel gas conduit 32Number is six, and the number of periphery air hose 42 is six.
In a kind of preferred embodiment of the present invention, the caliber of fuel gas conduit at the same level, the distribution density of gas jet orifice and holeDiameter size is identical.Gas jet orifice in center fuel gas conduit 31, periphery fuel gas conduit 32 and fuel gas conduit at different levels is annular in the axial directionDistribution.
Each fuel gas conduit is supplied by corresponding gas manifold 5,5 caliber of gas manifold and distance phase of fuel gas conduit preferably at the same levelDeng.
In the present invention, one end that each air hose is located at outside mixing chamber is connected to air duct 1, by the unified air feed of air duct 1.
In a kind of preferred embodiment of the present invention, the caliber of air hose at the same level, the distribution density of air jet orifices and apertureSize is identical.Air jet orifices on level-one air hose 41, periphery air hose 42 and air hose at different levels annular spread in the axial direction.
In another preferred embodiment of the present invention, as shown in figure 3, point of the caliber of air hose at the same level, air jet orificesCloth density is identical with pore size.Air hose 42 unilateral side in periphery opens up air jet orifices, and opening direction is towards center fuel gas conduit 31, i.e. courtAir jet orifices are not opened up to 42 side of periphery air hose of 1 internal layer wall surface of air duct.The unilateral side aperture mode, so that periphery air hose 42 and windThe direction of air jet orifices is consistent on cylinder 1, avoids influencing the air inflow of air duct 1, reduction pair due to the multi-faceted aperture of periphery air hose 42The timely mixing for the combustion gas that periphery fuel gas conduit 32 sprays.
As shown in figure 4, level-one air hose 41 or other air hoses at different levels are full wall surface aperture, which can be with its weekThe combustion gas for enclosing the fuel gas conduit ejection of distribution moves toward one another, and the air-flow of generation is conducive to quickly break up combustion gas, conducive to the combustion of disperse formula is formedIt burns, burn seedless heart district and high-temperature region, reduces heating power type and Quick-type NOx is generated.
In the present invention, multiple groups fuel gas conduit and air hose with several spray orifices can improve combustion gas and the mixing of air, oneA flame is divided into several flammules, and the thickness of flame front is thinned, and heat dissipation area increases, and flame temperature reduces, while negative in burningIn the case that lotus is constant, short and small flame even nonflame shortens the residence time of oxygen, nitrogen in high-temperature region.Furthermore multiple spot arrangement pointThe mode for dissipating burning, avoid calorific intensity concentration of local, the disperse nucleus of flame of high-temperature region, flame region more uniform temperature,Factors above has apparent inhibiting effect to " thermal NO x " and " fuel type NOx ".
In the present invention, fuel type NOx is that the nitrogen as contained in fuel is formed in fuel combustion.Temperature is to combustionThe generation influence of material type NOx is not obvious.
Thermal NO x generates what the nitrogen mainly in burning, in combustion air generated under thermal-flame through oxidation, temperatureDegree, excess air coefficient and high-temperature region residence time can all influence the generation of thermal NO x.Wherein temperature is that heating power type is mainInfluence factor, Actual combustion process due to temperature distributing disproportionation is likely to result in high-temperature area and cause NOx generate increase.
Also from aflame air, Quick-type generates mainly due to hydrocarbon nitrogen in Quick-type NOxIn burning, a large amount of CH, CH can be decomposited: and C: groups are waited, the molecular link of nitrogen can be destroyed, and then generate NOx.QuicklyType NOx be mainly in fuel hydrocarbon fast reaction generate.
Excess air coefficient is two-sided effect to the thermal NO x influence generated, and Actual combustion situation is increasingly complex.It has served asWhen surplus air coefficient becomes larger, oxygen concentration becomes larger, and promotes chemical reaction equilibrium mobile, increases the production quantity of NOx；It is same with thisWhen, become larger with excess air coefficient, generates exhaust gas volumn and also become larger, ignition temperature is reduced, to reduce generating rate.Therefore mistakeThe influence of surplus air coefficient is complex, it may be possible to which promotion is also likely to be inhibiting effect, to be analyzed according to the actual situation.General feelingsStop of the reaction in high-temperature region is longer under condition, and the production quantity of NOx is bigger.
Excess air coefficient is the Quick-type NOx influence generated, one timing of temperature, as excess air coefficient becomesGreatly, NOx generation amount, which first becomes larger to reduce afterwards, will appear peak value.
The nitrogen that excess air coefficient influences to be in fuel on the generation of fuel type NOx is converted to the conversion ratio of NOx with mistakeSurplus air coefficient increases and increases；As excess air coefficient a > 1, fuel NO_x production quantity is held essentially constant；Work as excess airWhen coefficient a < 1, conversion ratio can decline quickly.
The present invention is to provide a kind of classification dispersed combustions, divide flame and remove high temperature core, low coefficient of excess air, nonflameThe embodiment of low nitrogen.
In a kind of preferred embodiment of the present invention, the diameter of the gas jet orifice of center fuel gas conduit 31 is greater than combustion gas at different levelsThe diameter of pipe or periphery fuel gas conduit 32, preferably in center fuel gas conduit 31 to the direction of periphery fuel gas conduit 32, the combustion gas of fuel gas conduitInjection diameter is on a declining curve, is conducive to realize that air feed and combustion gas different ratio further decrease nitrogen oxygen to form fractional combustionThe discharge of compound.Generally, fuel gas conduit 31 surrounding air excess coefficient in center is less than 1, and the air excess system of periphery fuel gas conduitNumber is greater than 1, realizes fractional combustion.
In the present invention, as shown in figure 5, burner further includes igniter and ion inductive needle.Installation is set in side plate 2Igniter and ion inductive needle are so that the firing tip of igniter and the induction end of ion inductive needle protrude into the peace of mixing chamberFill hole I and mounting hole II.Preferably, mounting hole I 6 and mounting hole II 7 is arranged close to center fuel gas conduit 31, with rapid-ignition orDetect ionic current.
In the present invention, the flue gas thermal energy with higher and kinetic energy generated after burning in mixing chamber, in mixing chamberThe raising of pressure, flue gas can the spontaneous opposite side by side plate 2 mixing chamber is discharged, carry out subsequent heat transfer process.Flue gas fromThe process for opening mixing chamber drives without additional blower, reduces energy consumption.
Another aspect of the present invention is, provides a kind of nonflame low nitrogen burning method, and this method includes making combustion gas and high temperatureHigh-speed air moves toward one another, and burns after being diluted by high-temperature flue gas.
Preferably, method is implemented by above-mentioned nonflame low NO in the present invention.
When burning, the spray orifice high speed jet of several groups is passed through in air and combustion gas, and volume participates in burning after inhaling surrounding flue gas, emptyOxygen concentration and gas concentration in gas are reduced because being diluted, and combustion velocity is slack-off.High-speed flow, lower combustionReaction speed is burnt, the burning of disperse formula is formed.
Embodiment
Embodiment 1
As shown in Figure 1, a kind of burning nonflame low NO, air duct 1 and side plate 2 surround cylindric mixing chamber, fuel gas conduitWith air hose protrude into mixing chamber with annular shape layering it is staggered, fuel gas conduit by be located at mixing chamber center 1 center fuel gas conduit31 and 6 periphery fuel gas conduits 32 form, and air hose is by 6 level-one air hoses 41 around center fuel gas conduit 31 and close to 1 outer wall of air duct6 periphery air hoses 42 composition, level-one air hose 41 is around center fuel gas conduit 31, and periphery fuel gas conduit 32 is between level-one air hose 41 and weekBetween side air hose 42, periphery air hose 42 is located at outermost.Center fuel gas conduit 31 and periphery fuel gas conduit 32 are full wall surface aperture；Periphery42 unilateral side of air hose opens up air jet orifices, and opening direction is towards center fuel gas conduit 31, level-one air hose 41 or other air hoses at different levelsFull wall surface aperture.
The diameter of air jet orifices is 2mm on air duct 1, and the distribution density of air jet orifices is 2000/square meter；, air preheat200 DEG C of temperature, air velocity is 15 meter per seconds；
The caliber of center fuel gas conduit 31 is 60mm, and the diameter of gas jet orifice is 1mm, and the distribution density of gas jet orifice is 580A/square meter, gas flow rate are 183 meter per seconds；
The caliber of periphery fuel gas conduit 32 is 25mm, and the diameter of gas jet orifice is 1mm, and the distribution density of gas jet orifice is 780A/square meter, gas flow rate are 183 meter per seconds；
41 caliber of level-one air hose is 60mm, and the diameters of air jet orifices is 8mm, the distribution density of air jet orifices is 590/it is flatRice, 200 DEG C of air preheating temperature, air velocity is 15 meter per seconds；
Air hose 42 caliber in periphery is 60mm, and the diameters of air jet orifices is 8mm, the distribution density of air jet orifices is 440/it is flatRice (distribution density is using entire air hose as benchmark), 200 DEG C of air preheating temperature, air velocity is 15 meter per seconds.
Combustion gas introduces internal gas manifold by external pipe in embodiment 1, then distributes through internal gas manifold intoHeart fuel gas conduit 31 and periphery fuel gas conduit 32, then spray into mixing chamber through gas jet orifice, and injection flue gas presses level-one air hose 41, periphery windThe sequence of pipe 42 is blended with air.Air introduces air chamber through external air channel, and 200 DEG C are preheating in air chamber (simultaneouslyAlso cool down mixing chamber, reduce in mixing chamber and sprayed by air port after flue-gas temperature to 1800K or less), respectively with center combustion gasThe combustion gas mixing that pipe 31 and periphery fuel gas conduit 32 spray realizes subdivision flame, and low concentration fuel and air, multistage are sufficiently mixed,Reduce and be homogenized ignition temperature, the disperse nonflame low nitrogen burning of low coefficient of excess air.
Embodiment 2
The step of structure and implementation of low NO and embodiment 1 are consistent, and difference is only that different zones injection diameterDifference, specifically:
The diameter of air jet orifices is 2mm on air duct 1, and the distribution density of air jet orifices is 2000/square meter, air preheat temperature200 DEG C of degree, air velocity are 15 meter per seconds；
The caliber of center fuel gas conduit 31 is 60mm, and the diameter of gas jet orifice is 1.2mm, and the distribution density of gas jet orifice is580/square meter, gas flow rate is 183 meter per seconds；
The caliber of periphery fuel gas conduit 32 is 25mm, and the diameter of gas jet orifice is 0.5, and the distribution density of gas jet orifice is 780A/square meter, gas flow rate are 183 cubes of meter per seconds；
41 caliber of level-one air hose is 60mm, and the diameters of air jet orifices is 8mm, the distribution density of air jet orifices is 590/it is flatRice, 200 DEG C of air preheating temperature, air velocity is 15 meter per seconds；
Air hose 42 caliber in periphery is 60mm, and the diameters of air jet orifices is 8mm, the distribution density of air jet orifices is 440/it is flatRice, 200 DEG C of air preheating temperature, air velocity is 15 meter per seconds.
Comparative example 1
A kind of combustion method for boiler " is divided using 08 month 2017 patent of invention filed in 09 day of the applicantGrade nonflame low nitrogen burning head " burner.
The structure of low nitrogen burning head and embodiment 1 are consistent, and difference is only that, fuel gas conduit is by being located at 1 of mixing chamber centerCenter fuel gas conduit 31 forms, and air hose system only includes the air duct 1 for participating in surrounding mixing chamber；
Wherein, the caliber of center fuel gas conduit 31 is 60mm, and the diameter of gas jet orifice is 1mm, the distribution density of gas jet orificeFor 580/square meter, gas flow rate is 183 meter per seconds；
The diameter of air jet orifices is 2mm on air duct 1, and the distribution density of air jet orifices is 2000/square meter；Air preheat temperature200 DEG C of degree, air velocity are 15 meter per seconds.
Experimental example
Burner and boiler are equipped, different load are adjusted, to CO (%), NOx (ppm), O in final tail gas2(%) contentIt is monitored, determines combustion case.Wherein, load refers to the percentage for reaching burner rated condition；O2(%) refers to mostO in finality gas2Percentage by volume；CO (%) refers to the percentage by volume of CO in final tail gas.
Table 1
Table 2
Table 3
By the related check data analysis to embodiment 1, embodiment 2 and comparative example 1, different zones injection diameter is adjustedIt is advantageous to reduction CO (%), NOx (ppm) discharge.The present invention is compared to the applicant's invention filed in 09 day in 08 month in 2017Patent " classification nonflame low nitrogen burning head " burner increases on the basis of center fuel gas conduit and mixing cavity wall air jet orificesI and II air hose and periphery fuel gas conduit, the structure of disperse nonflame low nitrogen burning more optimize, and realize low-nitrogen discharged burning dressIt sets the upper limit of the power and 800-1000KW is increased to by 200KW.
Combining preferred embodiment above, the present invention is described, but these embodiments are only exemplary, only play the role of illustrative.On this basis, a variety of replacements and improvement can be carried out to the present invention, these each fall within thisIn the protection scope of invention.