Simulation Study And Design Of Marine Diesel Particulate Filter

With the rapid development of shipping industry,marine diesel engines have become the main source of atmospheric pollution in port cities.Their exhaust pollutants affect the global environment with the atmospheric flow.As the main pollutant of marine diesel engine,the purification of particulate matter has drawn more and more attention.The installation of diesel particulate filter(DPF)is the most effective measure to reduce exhaust particulate matter,which is also the focus of research in recent years.In this paper,the DPF of a marine diesel engine was taken as the research object,and the simulation of DPF capture and regeneration process was carried out by using the simulation method.The DPF design work was completed.First,the DPF calculation model was established,and the DPF trapping process was simulated and analyzed on the basis of the experimental data.The pressure drop characteristics,soot trapping,trapping efficiency and flow rate characteristics during the process of trapping were studied.The influence of DPF structural parameters and diesel exhaust parameters on the performance were analyzed based on the trapping efficiency and pressure drop.The factors of airflow inside DPF were studied.The results show that the total pressure drop of DPF is composed of seven parts.The DPF captures soot in two ways: the soot accumulates before 0.7 g/L and then becomes the surface trapping.Secondly,the DPF regeneration model was established to analyze the change of DPF temperature,soot volume and pressure drop during regeneration process.The effects of exhaust gas temperature,exhaust oxygen concentration and DPF soot initial amount on regeneration were studied.The simulation results show that the higher the exhaust temperature,the higher the concentration of oxygen in the exhaust gas,the faster the regeneration reaction rate,and the more heat is released in a short time;The increase in the initial amount of soot does not change the temperature distribution trend of the DPF filter,but it will affect the maximum temperature of the filter body's average temperature.Finally,based on the research in this dissertation,a complete set of traps for a certain type of 140 kW marine diesel engine was designed based on the DPF related design method,and a DPF regeneration system was developed based on the domestic fuel injectioncombustion-assisted regeneration system.According to the DPF correlation parameters,combined with the actual operation requirements of marine diesel engine,the precise parameters of the control regeneration system are obtained.The research results of this paper can provide theoretical basis and engineering application reference for the design,selection and practical application of DPF for marine diesel engine,and lay a foundation for the experimental research of DPF in the next step.