Optimal Design And Simulation Optimization Of A New Type Of Marine Spray Desulfurization Tower Based On Waste Heat Recovery

With the development of global trade,the trade between countries tends to be frequent,and the maritime transport industry plays an important role in global trade.The environmental pollution caused by the sulfur oxides emitted by ships engaged in marine transportation is becoming more and more serious.The International Maritime Organization（IMO）has established multiple and stricter indicators for the emission of ship exhaust gas.Research on the control technology of ship sulfur oxide emissions has emerged as the times require.Ship exhaust gas desulfurization technology is the most widely used and the most practical in ship sulfur oxide emission control technology.The wet seawater desulfurization technology is the choice of most seaborne ships.The spray desulfurization tower in the wet seawater desulfurization system has a simple structure and is easy to maintain.The desulfurization tower uses sea water as a desulfurizer.The source of the desulfurizer is abundant.It is not easy to scale in the sprayed desulfurization tower.This paper uses ANSYS WORKBENCH software to carry out three-dimensional modeling of the simplified marine wet seawater spray desulfurization tower.The calculation area of the desulfurization tower is divided into the reasonable grids.The standard k-εturbulence model and particle trajectory model are selected according to the relevant assumptions of the calculation area of the spray desulfurization tower,and a model of SO₂ absorption by seawater is established based on the Euler-Lagrangian model and the double membrane theory.Import this model into FLUENT software through UDF interface.Use FLUUENT software to simulate and calculate the flow field distribution and SO₂ absorption status of the marine wet seawater spray desulfurization tower.The simulation results show that there is a problem of flue gas drift in the traditional marine wet water spray desulfurization tower and the desulfurization efficiency of the desulfurization tower is low.This article is to alleviate the phenomenon of flue gas drift in the traditional marine wet water spray desulfurization tower and improve the desulfurization efficiency of the desulfurization tower,a waste heat recovery device is added inside the desulfurization tower to optimize the flow field distribution in the desulfurization tower,aiming at the typical working conditions of waste heat recovery spray desulfurization tower,multi-parameter simulation calculations were performed on operating parameters such as the velocity of the inlet flue gas in the waste heat recovery spray desulfurization tower,the liquid-to-gas ratio,and the initial SO₂ mass fraction contained in the inlet flue gas;In order to improve the desulfurization effect of the marine seawater wet waste heat recovery spray desulfurization tower,based on a new type of desulfurization tower model with waste heat recovery,replace the first spray layer with a spray layer to improve its spray conditions,through optimization calculation of design parameters such as spray nozzle angle,spray layer spacing,spray seawater temperature,and spray layer position,the best spray parameters of the desulfurization tower are obtained.The simulation results show that the installation of a waste heat recovery device in the traditional marine seawater wet spray desulfurization tower can effectively alleviate the deviation of the flue gas in the desulfurization tower,improve the uniformity of the flue gas distribution in the desulfurization tower,and improve the desulfurization efficiency of the desulfurization tower.The desulfurization efficiency of the waste heat recovery seawater wet spray desulfurization tower is 78.62%;the desulfurization efficiency of the waste heat recovery spray desulfurization tower is negatively related to the inlet flue gas velocity,it is positively correlated with the liquid-gas ratio,it is negatively correlated with the initial mass fraction of SO₂ in the inlet flue gas,there is a negative correlation with the angle of the spray nozzle,it is positively correlated with the spacing of the spray layer,it is negatively correlated with the temperature of the sprayed seawater;the angle of the best spray nozzle of the waste heat recovery spray desulfurization tower is 170°,the best spacing of the spray layer is 2.5m,the best temperature of spraying sea water is 300K,and the best position of the spray layer is the first layer.Based on the best spray parameters,the desulfurization efficiency of the desulfurization tower is 96.32%.