The Research Of An Low Nox Coal Burner Of Tiny Disturbing Stream And Precessing Jet Flow

Low NO_x burner is very important content of low NO_x combustion technology,at alltime it is studying emphasis of low NO_x technology. The research is based on whichprecessing jet can intensify large scale mixture of fuel and oxide and devise two new typesof precessing burners and investigate their NO_x characteristic.The liquid of precessing jet on the effect of some stimulation,gives birth to one motionof the azimuthal oscillation of a jet flow about an axis other than its own centre-line.Thesepresessing flows have been demonstrated to be beneficial to combustion,it increases flowmotion,boostes up the large scale mixture,and minishes small scale mixture,reduces srainratesof the flame,lead to the increase of soot in the combustion.The increased volume ofsoot leads to increased radiation,which in turn acts to reduce flame temperature,so theprecessing jet combustion can reduce NO_x emissions effectually.we have devised two different struction of precessing burners in the passage, triangleorificeburner and loudspeaker-mouth burner and took a pilot experiment and numericalsimulation to two new types of burners.The pilot experiment is carried out through in0.3MW uprightness furnace with more advanced apparatus and compare the experimentdata with swirl burner,we have carried parallel experiment of three burners with the samecoal quantity and wind quantity and so on.As a result,triangle-orifice burner andloudspeaker-mouth burner have an evidence effect in lessening NO_x,its NO_x emissionseparately are lower than the former devised swirl burner 29.1% and 35.8%.At the sametime,the two new types of burners come into being more high temperature zone than swirlburner,indicate that the mixture of fuel and air is strengthened.Computational Fluid Dynamics(CFD) have becomed more and more important meansof the burner exploiture and research,we have used Fluent software to simulate the swirlburner,the triangle-orifice burner and the loudspeaker-mouth burner in the passage,obtainedthe detail data of the temperature field,the concentration field and the velocity field ofburners.The simulation makes clear that the flow field of two new types of burners areobvious different with swirl burner,new type of burner can intensify the large scal mixtureof fuel and air.The performance of combustion become more stabiler,at the same time,theNO_x emission are separately 183ppm and 195ppm,is lower than swirl burner,this shows that precessing jet can cut down small scale mixture effectively.The pilot experiment and numerical simulation idicate that triangle-orifice burner andloudspeaker-mouth burner have an evidence effect in lowering NO_x.In the future,we shouldcarry some work as follow:research the adaptability of precessing jet and coal specific;someexperiment under different load,in order to know the adaptability of load and precessingjet;integrating these two new types of burners,boosting up the burny satbility and thecharacteristic of low NO_x emission,as well as the adjusting of burning situation.