Numerical Simulation Of Aggregation Kernel Of Turbulence And Brown Synergizing Vapor Condensing On The Surface Of Fine Particulate Matter

PM does enormous harm to the quality of air so that social environment and human health is under serious detriment.One of the main sources of PM is from coal-fired power plants in spite of most of which under electric precipitation due to the non-ideal removal efficiency on PM with size order of 10-6m.Growth and aggregation of PM is an efficient technique catching and collecting of preventing PM from escaping into air and the key of improving the efficiency of the technique is researching the mechanism of PM with size order of 10-6m growing and aggregating in reactor.The growth rate model of vapor condensing on the surface of PM is built via laws of mass conservation and energy conservation.Under different surrounding temperature distribution,different forms of solutions to the model are shown.Dynamic analysis is made to build up the term structure model of particle size distribution and numerical solutions of which describe that how initial particle size distribution and supersaturation of vapor produce an effect on vapor condensing time and particle size in the stable stage.Solutions demonstrate that the process of PM in reactor provide enough time for PM to grow up to stable stage and quickly increased size and mass of PM create a favorable condition for them to be removed in demister.For the spray space of desulfurizing tower that added the vapor inlet,a reactor of PM aggregation kernel synergizing vapor condensing was built to investigate the mechanism of ultrafine particle condensation,growth,as well as its removal.To clear the impact of heterogeneous condensation which combined with turbulent Brownian motion,the dynamic model of superfine particle growth by vapor condensation,the aggregation kernel models,as well as the Brown model were introduced in.Furthermore,the on-way mechanism of ultrafine particle was studied for the first time by means of written the dynamic model of particle growth to the PBM.The results show that the over saturated degree was increased by vapor addition.Meanwhile,the Brownian motion and turbulent motion of ultrafine particle is significant at the reactor inlet,which could greatly improve the removal efficiency of ultrafine particle.Simulation solutions show that though gas is unsaturated and bigger relative humidity at the stage of vapor inlet zone,high humidity in the whole reactor provide a good and available condition to vapor to condense.PM1.0 aggregating effect is obvious due to the apparent influence of turbulence and brown.Adding vapor could promote the growth effect,which indicate the technique is feasible.When no vapor added into the reactor,average removal efficiency decrease tremendously.