A Forecasting System And Modeling For Diffusion Of Ship Exhaust Emission

Waterway transportation accounts for about 50%of marine pollution.Among them,ship exhaust emission has a serious impact on the marine environment and the atmospheric environment of the port area.Harmful gases in the ship's exhaust emission may damage human health and become an important source of air pollution,and have received widespread attention from society.Therefore,it the plays an important role in the atmospheric environment control and cause analysis of the port area to analyze and research ship emission diffusion.In this paper,the Gaussian plume model is improved to realize the construction of the ship emission diffusion model in the marine environment,and a forecasting system is formed.The specific research contents are as follows:Firstly,the wind field intensity information of the corresponding sea area is obtained by ship instrumentation or marine weather map;after the uniform dimension,the Pasquill atmospheric stability is determined by the wind field intensity,the amount of daytime radiation,and the nighttime cloud amount.The Briggs diffusion coefficient is determined by the above-mentioned atmospheric stability,and the input parameters are provided for the ship exhaust diffusion model based on hydrometeorological input parameters.Reasonable consideration of marine environmental factors,the actual direction of exhaust emission diffusion is determined by vector synthesis,thus providing a new "synthetic wind speed" for the improved model,using this wind speed for simulation calculation,effectively simulating the ship exhaust emission in the port area or marine environment Diffusion model.Secondly,a new method was proposed based on dynamic parameters and static parameters of ships that combines the ship's emissions inventory,ship's main engine power,and auxiliary machine power to calculate the source strength(Q)derived from the ship's exhaust.It can effectively replace the measured data and make the model input simple.Thirdly,using the modified Gaussian plume ship exhaust emission diffusion model,the ship speed(v),wind speed(u0),heading angle(0),pollutant concentration(Cs),atmospheric stability(AS)are controlled by the control variable method.The experiments with the above five parameters have different effects on the ship's exhaust emission diffusion,and the wind speed(u0),and pollutant concentration(Cs)have the most significant impact on the ship's exhaust emission diffusion.Comparing the improved model with the original model,the results show that after the vector is synthesized,the wind field strength magnitude and direction error correction are 38.2%and 51.6%,indicating that the improved model can be effectively applied to analysis and research for ship exhaust emission diffusion.Finally,using the improved ship exhaust emission diffusion model to calculate the concentration data of each region,by setting the threshold value,the concentration data is binarized,and the calculation method of the ship exhaust emission high concentration area is designed to solve the high field of view.Concentration area.The diffusion concentrations of different sampling periods are superimposed to obtain a dynamic diffusion map.According to the above algorithm and the improved model,the ship exhaust emission diffusion forecasting system is constructed to make the ship exhaust emission diffusion forecasting fast,intelligent and systematic.This paper is aimed at the impact of shipping on the atmospheric environment,and studies the ship exhaust gas diffusion forecasting system.This system is combined with ArcGIS to apply the smoke diffusion of the "Sanchi Ship" accident to further optimize the marine environment and the atmospheric environment analysis or marine accident in the port area.Provide emergency technical assistance and other technical support.The future research direction is explained.