Diesel Engine Response Improvements using Hybrid Turbocharging

Abstract

Turbochargers are commonly used with internal combustion engines due to improvements in power and efficiency and reduced emissions over naturally aspirated engines. A central problem of turbocharged engines poor transient performance characterized by turbo-lag. While the engine itself may respond quickly to load and speed changes the delays associated with the inertias of turbocharger systems make the system as a whole respond accordingly.

In this thesis potential response improvements by use of an electrically assisted turbocharger, or hybrid turbocharger, were presented in simulations. Response improvements of 10-50 % were shown for various transients and degrees of assistance. A design proposal for the implementation of the system is also presented. The results could form a basis for implementing a hybrid turbocharger on an engine in the lab in further work.