| As a main electronic control fuel supply system,electronic unit pump(EUP)fuel injection system has the advantages of flexible control and high response,offering a reliable and effective technical way to meet future emission standard.Therefore,EUP has high research value.EUP fuel injection system is a complex system involving many areas,and it is usually composed by electronic control system,electromagnetic conversion system,mechanical system and hydraulic system to display the system function.There are interrelated,interactional and mutual coupling relationships among each system.This article will use 3D joint simulation method of electromagnetic,machine and fluid on the platform of ANSYS Workbench,to research the complicated relationships between each subsystem of EUP fuel injection system.The research work of this thesis and the relevant achievements are mainly embodied in the following aspects:First of all,the thesis carried out a 1D performance simulation research of EUP fuel injection system.The 1D simulation model of EUP fuel injection is set up by AMESim software.The change rules of cavity pressure,pump pressure and cycle fuel injection quantity are researched through changing the characteristic parameters of EUP(high-pressure oil duct diameter,spring pre-tightening force of control valve,high-pressure tubing length,high-pressure oil pipe diameter and sectional area of nozzle),And the influence of characteristics parameters on spray characteristics.The conclusion is that the fuel injection quantity is the largest when the high pressure oil duct diameter is 2.0 mm,control valve spring pre-tightening force is 60 N,high-pressure tubing length is 130 mm,inner diameter is 2.0 mm and nozzle hole diameter is 5.0mm.Secondly,the article conducted a coupling simulation research of electromagnetism,machine and fluid during the supply process of EUP.On the ANSYS Workbench platform,The Maxwell and Fluent are used to build the electromagnetic valve model and 3D flow field model.The data transmission between different modules is achieved by the UDF program,which realized the 3D coupled simulation of multicomponent systems.The change rule of dynamic responses characteristic of valve core and the flow field characteristic parameters are getted under the different valve opening.In addition,the article studies the influence of solenoid valve parameters on the 3D flow field in the supply process of EUP fuel injection system.Through changing the coil number of turns,spring pre-tightening force and moving parts mass of electromagnetic drive system,the mechanism analysis are conducted of complex coupling relationship among several factors.The conclusion is that when the coil turn is 75 turns,the control valve spring pre-tightening force is 75 N and moving parts mass is 17 g,the dynamic response of monomer pump fuel system is the highest,the highest peak mass flow rate is minimum and turbulence intensity is the most obvious.Finally,the article established the internal flow field model of unloading prograss of EUP fuel system,and analyzed the influence of boundary conditions and structure parameters of control valve cavity on the flow characteristics during oil unloading process.And the paper sums up the influence of boundary conditions and structural parameters on pressure distribution of flow field,fuel velocity,turbulence kinetic energy distribution and oil discharge rate.The conclusion is that the circulation characteristics of oil unloading process the best when the boundary pressure peak value is 180 MPa,control valve sealing diameter is 11.0 mm and the seal cone angle is 145°. |
