Research On Simulation Optimization Of Magnesium Process Marine Waste Gas Desulfurization Tower

Due to the frequent global trade contacts,the marine transportation industry is booming.The SO_xpollution problem caused by running the ship is getting worse.The International Maritime Organization（IMO）has made strict regulations on the emissions of ships SO_x.The use of flue gas desulfurization technology is the most practical solution to meet the strict requirements of IMO.In this paper,the main flue gas desulfurization technology at home and abroad and its adaptation to the ship environment are compared.It is concluded that the spray desulfurization tower used in the magnesium desulfurization technology is simple in structure,easy to maintain,and uses magnesium hydroxide solution and seawater.As a desulfurizing agent,it is relatively easy to obtain and there is no problem such as scaling.In this paper,the ICEM software is used to mesh the simplified calculation model of the traditional marine spray desulfurization tower.The Realizable model and the Euler-Lagrange model are selected according to the relevant basic assumptions.SO₂absorption model,imported into Fluent software through UDF interface,the simulation of the velocity flow field,pressure distribution and absorption of SO₂in the spray desulfurization tower were carried out and related experiments were carried out.Among them,the spray desulfurization tower considers the operating parameters such as opening and closing the spray layer smoke,the liquid-gas ratio,the flue gas inlet flow rate,the initial SO₂mass fraction,etc.;the different flue gas inlet angle,the inlet ratio,the entrance and exit arrangement And other structural parameters;the different nozzle positions of the flue spray technology and the influence of the atomizing nozzle flow on the gas-liquid flow field and the desulfurization process in the spray desulfurization tower.The simulation calculation results and experimental results show that for the marine spray desulfurization tower:the slurry droplets sprayed by the spray layer have a strong"rectifying effect"on the smoke flow field,and the spray desulfurization tower is not formed when other operating parameters are not changed.The desulfurization efficiency decreases with the decrease of the liquid-gas ratio,and the inlet flow rate of the flue gas and the initial mass fraction of SO₂decrease;the down-dip angle of the flue gas inlet of the spray desulfurization tower is recommended to be about 5°.The proportion of the flue gas inlet of the spray desulfurization tower is recommended to be about 0.8.This ratio structure design can effectively avoid the disadvantage that the ratio is too small and too large.The proportion is too small,the diffusion process of the flue gas entering the spray tower is slow,and the flow field uniformity is deteriorated.If the ratio is too large,the strength of the spray tower will decrease,which may cause safety problems.When the atomizing nozzle is installed only in one position,it is installed on the left side of the inlet flue in the direction of flue gas inflow,and the desulfurization efficiency is the best.When the atomizing nozzles are installed on the side of different combinations,the desulfurization efficiency is the best when the flue gas inflow direction is installed on the left side and the right side of the inlet flue,and the desulfurization efficiency of the desulfurization tower increases as the atomizing nozzle flow rate increases.