Analysis And Optimization Of Pressure Field Of 16V280 Diesel Engine Oil Outlet Valve Chamber

Since the speed increase of railway locomotives,the cavitation corrosion problem of16V280 ZJ diesel engine’s internal outlet valve couple is very serious,which leads to cylinder knocking,high fuel consumption rate,red and hot exhaust pipe,continuous black smoke and other phenomena.The serious situation may even cause wear and damage of diesel engine parts,greatly reducing the working efficiency and service life of diesel engine,Therefore,it is necessary to carry out the finite element analysis and structural optimization of the outlet valve couple.In order to improve the usability and economy of the improved outlet valve couple,the static and fluid analysis of the original outlet valve couple of 16V280 diesel engine was carried out by finite element simulation,and the results of the structure static analysis and cavity pressure field analysis of the original outlet valve were obtained.By using the optimization algorithm,the thickness of the cross wall(four places)on the lower side of the oil valve is defined(positive is thickening,negative is thinning).In a reasonable range of values,multiple groups of data are input(each group of data is the four change values of the cross wall on the lower side of the oil valve),and the pressure change value(proportional to the energy loss)and cavitation erosion at the inlet and outlet of the oil valve cavity are optimized,The optimal model is obtained,and the performance of the outlet valve before and after the improvement is compared through the simulation results.The thickness of the cross wall(four places)on the lower side of the optimized outlet valve is reduced by about 0.1 mm.In the simulation state,the unit pressure(i.e.1 MPa)at the inlet of the valve chamber is given.The pressure change value at the inlet and outlet of the valve chamber is changed from 0.436 MPa to 0.408 MPa,the pressure change value is reduced by 7%,and the energy loss at the inlet and outlet is reduced;The cavity volume increases by 3%,which reduces the pressure fluctuation in the later stage of injection,and reduces the generation of negative pressure in the high pressure cavity;The maximum stress and displacement increase by about 30 MPa and 0.0002 mm respectively,but they still meet the requirements of strength and deformation.The optimized outlet valve not only alleviates the cavitation problem,but also reduces the energy loss;It also improves the fuel flow capacity in the cavity,and has a significant effect on reducing the fuel consumption and pollutant emission of diesel engine.