Study on EGR Optimization Strategies in Transient Process
Real-time measurement of exhaust gas recirculation （EGR） flow with good stability, high accuracy and precision of EGR rate was made using the Coriolis flow meter on a turbocharged and intercooled heavy-duty high pressure common rail diesel engine. Engine performance at constant speed and increasing toque （CSIT）process were conducted under 1 650 r/min speed of steady test cycle condition. Test results show that applying the optimized EGR rate and injection parameters under ESC conditions to the transient process will cause a serious deterioration of soot emission regardless of any EGR optimization strategies, and smoke opacity increases up to 50% because of overshoot of EGR rate. Mode switching between opti- mized EGR and multi-injection coupled with EGR in transient process can effectively decrease NOx emissions while the strategy of timely EGR closure can obviously decrease the soot. Adjusting the air-fuel mixture ratio and time distribution in various stages of transient process can effectively control the overshoot of EGR rate and decrease the smoke opacity by 20%.
NETL
NSTL
万方数据
维普
