Calculation Study on the Variable Geometry Exhaust Manifold Turbo-charging System for the 8170 Diesel Engine

In order to make the diesel engine can give a good performance both at the high load operation and the low load operation,a newly designed variable geometry exhaust manifold(VGEM) turbo-charging system was put forward for this engine.The VGEM turbo-charging system can realize the switch between two charging modes by the controllable valve.The simulations of the system in both steady state and transient state had been done.The steady simulation results indicated that in all 4 loads of 25%,50%,75% and 100%,the scavenging coefficient of the VGEM turbo-charging system is bigger than that of the MPC turbo-charging system,the BSFC of the VGEM turbocharging system is smaller than that of the MPC turbocharging system.The transient simulation results indicates that when the controllable valve is closed,the intake pressure after compressor increases more.