Study On Optimal Configuration Of Multi Nozzles Of Wet Flue Gas Desulfurization

Industrial sulfur dioxide emissions have brought tremendous environmental damage and economic losses to the whole world.The control of industrial emissions of sulfur dioxide is important for improving air quality.The key component of desulfurization spray tower is the atomizing nozzle,the most basic reaction unit is the slurry droplet.Therefore,the configuration parameters of desulfurization nozzle have a great influence on the mass transfer process.Study on this influence,which provides a theoretical basis for the configuration design of the nozzle,has an important practical value.This paper takes EDV desulfurization tower as an example,based on the double film theory,established the mass transfer model of SO₂.The mass transfer rate equation of SO₂ was determined.A mathematical model for the motion of droplets in spray tower is established,determined the critical particle size of different operating gas velocity.And the equation for calculating the residence time of flue gas is obtained.The mathematical model is established to study the influence of spray droplet size,spray intensity and initial velocity on the pressure drop of the spray layer.According to the results of theoretical research,the Fluent software is used to simulate the gas liquid two phase flow in the desulfurization tower.Study on the influences of nozzle configuration parameters on the desulfurization tower flow field.The results indicate that the spray liquid droplets play an intensive flow straightening role with regard to the flue gas flow field,improve the uniformity of flow.With the increase of the spray cone angle,the area of high turbulence increases gradually,which is helpful to improve the mass transfer rate.Increase the number of nozzle can improve the uniformity of the tower inner flow,reducing the average turbulence intensity.Compare with inline arrangement,staggered arrangement is more conducive to extending the time of gas-liquid contact and mass transfer reaction.Increase the spray layer number make the uniformity of tower inner flow field improved significantly.Used Barracuda-the CPFD software-for numerical simulation of tower desulfurization process,explores the calculating model for gas-liquid flow simulation of desulfurization spray tower.The relationship between nozzle configuration parameters and desulfurization efficiency was studied quantitatively.The result shows that the desulfurization efficiency is inversely proportional to the droplet diameter,proportional to the spray cone angle and the ratio of liquid to gas ratio,and first increase then decrease with the increase of the initial velocity of the droplets.Through the sensitivity analysis of the influencing factors,it was found that the liquid gas ratio was the most important factor to the desulfurization efficiency,followed by the droplet size and spray cone angle.According to the results of the study,relevant principles of desulfurization spray tower nozzle configuration are given.According to the results of the above study,selected the nozzle configuration scheme,and the two-level fuzzy integrated evaluation is carried out.The evaluation result shows that the scheme?is the best scheme,in which the liquid gas ratio is 6.5 L/m³,the spray cone angle is 160°,spray droplet size is 1.2 mm,and spray layer spacing is 1.5 m.