Based on a D19 high pressure common-rail diesel engine with VGT (variable geometry turbocharger)

an one-dimensional thermodynamic engine model and a three-dimensional CDPF (catalytic diesel particulate filter) model were built by using the GT-Power and AVL Fire. At 3 000 r/min with 50% load

the effects of fuel injection strategy with EGR (exhaust gas recirculation) on engine combustion process and CDPF regeneration performance were studied. The results show that

with the advance of the main-injection timing

the BSFC (brake specific fuel consumption) decreases first and then increases

and the exhaust temperature reduces

while the changes of the exhaust flow and oxygen concentration are not obvious. In addition

the NO in exhaust increases

the CDPF regeneration rate decreases gradually

and the residual particulate matter

pressure drop

as well as NO2 at the CDPF outlet increase simultaneously. With the increase of the EGR rate

the BSFC and exhaust temperature increase

while the exhaust flow

oxygen concentration and NO in exhaust all reduce simultaneously. With delayed main-injection timing

the CDPF regeneration rate increases first and then decreases as the EGR rate increases

while the residual particulate matter decreases first then increases slightly. With earlier main-injection timing

the CDPF regeneration rate reduces while the residual particulate matter increases as the EGR rate increases. With later main-injection timing

increasing the injection pressure can decrease the BSFC and exhaust temperature obviously

while with earlier main-injection timing

improving the injection pressure can increase the BSFC greatly. In addition

with the increase of the injection pressure

the changes of the exhaust flow and oxygen concentration are slight

the NO in exhaust increases

the CDPF regeneration rate decreases slowly

and the residual particulate matter

pressure drop as well as NO2 emission at the CDPF outlet increase simultaneously. In short

compared with the injection pressure

the influence of the main-injection timing on the CDPF regeneration process is greater.