Research On Numerical Simulation Of Fuel Injection Regeneration Of Marine Diesel Particulate Filter

Today’s rapid development of the shipping industry,the pollution problems caused by diesel emissions from ships are thoroughly exposed,and the problem of particulate matter emission reduction has become imminent.At present,the most effective means to reduce particulate matter is to install diesel particulate filter.To solve the regeneration problem of diesel particulate traps for ships,in this paper,we will take the marine diesel particulate filter as the research object and use the numerical simulation method to explore and study the trapping and regeneration process of the marine diesel particulate filter.In this paper,firstly,a mathematical model of the trapping and injection regeneration process of marine diesel particulate filter was established and model comparison was verified.On this basis,a numerical simulation study of the effects of changes in porous media permeability,particulate matter particle size and inlet velocity on the internal flow characteristics was carried out.Then,UDF and UDS were written to interface the reaction kinetics model of thermal oxidation of particulate matter with the solver to establish the transient numerical simulation model of fuel injection regeneration,and the numerical simulation study was carried out to investigate the influence law of temperature peak,residual amount of particulate matter and residual amount of diesel vapor in the regeneration process from four aspects: inlet temperature,inlet velocity,initial diesel vapor amount and injection time point.The numerical simulation results show that: the wall trapping starts from the end,and the distribution of large particle size is more backward;the trapping distribution tends to be more uniform as the permeability decreases;and the increase of the inlet velocity will make the particle distribution more uneven.In the regeneration process,the inlet temperature is too high,the temperature gradient is too large,burning the filter body,the inlet temperature is too low,the temperature peak is too low to meet the regeneration temperature conditions;the inlet velocity is too large,the temperature rise will be accelerated,but the temperature peak is reduced,and the loss of diesel vapor increases;increasing the initial amount of diesel vapor will lose more diesel vapor in the preheating stage,but can increase the temperature peak of the filter body;delaying the time point of starting fuel injection can effectively reduce the amount of diesel outflow in the preheating section,and the effect on the temperature field of the regeneration process is not significant,which is more beneficial to the regeneration process.The conclusions from the numerical simulation analysis study conducted in this paper can provide a theoretical basis and application reference for the fuel injection regeneration of marine diesel engine particulate traps,which can lay the foundation for the subsequent bench test study.