Test And Simulation Analysis Of Marine Diesel Particulate Filter

Particulate matter(PM),as one of the main products of diesel engine emissions,has become more and more serious to the environment.Compared with gasoline engines,diesel engines emit more than tens of times more particulate matter.Therefore,at present,every country in the world has put forward strict standards for particulate matter emissions from diesel engines,which makes it necessary for diesel engines to establish a post-processing system in order to meet their emission standards.Diesel particulate matter trap(DPF)is one of the most effective post-treatment devices to reduce particulate matter emissions.However,the installation of DPF increases the exhaust back pressure of diesel engine,reduces engine efficiency and has a certain impact on its performance.Therefore,the rationality of DPF structure design becomes the focus of design.With the development and perfection of CFD computing technology,it has already been applied to DPF performance analysis and structure design,which makes up for the shortcomings of traditional design and improves its design process.In this article,the DPF is taken as the research object and the velocity and pressure of its internal flow field are analyzed by the method of combining experiment and simulation calculation.Based on the analysis results,the DPF structure optimization design is carried out.Firstly,according to the existing test equipment and literature,the structure scheme of DPF is designed,and the construction of the test bed is completed.DPF performance test was carried out under different working conditions of diesel engine,including capture efficiency test,pressure drop characteristic test and temperature characteristic test.Secondly,according to the design scheme,the three-dimensional Creo software is used to build the simulation model of the solid shell,and then the ANSYS FLUENT software is used to build a complete three-dimensional CFD calculation model of DPF.The SIMPLE algorithm is used,and the standard k-ε two-equation turbulence model is used to simulate the internal flow field of DPF.The air flow and pressure distribution in DPF were obtained by simulation calculation.Then,the axial and radial velocities of air flow in different inlet velocities,different expansion angles and different contraction angles of DPF are analyzed,and the effects of different factors on the uniformity of air flow in DPF are studied.Finally,according to the results of analysis and calculation,the structure is optimized to make the internal flow field more uniform,and the structure is reduced by static pressure and pressure drop.Similarly,the axial velocity,radial velocity and pressure distribution in DPF are compared with the existing calculation results,and the optimization is verified.