The Research On Miller Cycle And EGR Technology Of Diesel

With the problem of energy and environment increasingly prominent,regulations of diesel engine is becoming more and more strict,reducing harmful emissions of diesel engine,at the same time,ensuring the performance and fuel economy of diesel engine is very important.Due to the miller cycle and exhaust gas recirculation(EGR)in reducing diesel engine's NO emissions has tremendous potential and apparent advantage,and it is easy to implement the two technologies on diesel engine,this paper studies these two technologies.Choose a certain type of diesel engine as the research object,software FIRE is used to establish engine three dimensional simulation platform,and through comparing with the test data,which verify the accuracy of the simulation platform.Next to simulation research of miller cycle and EGR,and the two combined technology,analyze the influence of diesel engine combustion process and NO emission.Based on diesel engine performance,fuel economy and emission characteristics of comprehensive consideration,select the best degree of miller and EGR rate matching values,and on the basis,optimize the injection advance angle and compression ratio,it is concluded that optimal matching result.Simulation results show that when using miller cycle of diesel engine,as miller degree increases,the highest average temperature in cylinder reduce,ignition delay period increase,CA50 delay and combustion duration reduce,comprehensive analysis,the optimal degree of miller is M60,compare with the original condition,at 25% load,NO falls by 7.6%,while 50% load,NO falls by 38.9%,while 75% load,NO falls by 42.5%,when 100% load,NO falls by 49.8%.When the miller cycle and EGR are combined,NO emission of diesel engine can reduce further,meantime the performance and fuel economy of diesel engine remains the same basically,propeller characteristics of75% load,when miller cycle and EGR are combined,the best match value of miller degree is 60 and EGR rate is 0.1,relative to the M60 miller degree,EGR rate is zero,NO falls by 61.5% Diesel engine compression ratio and fuel injection advance angle is optimized,the best optimization results of compression ratio is 13.5,fuel injection advance Angle is.21? A.