Investigation of the ion current signal in Gen-set turbocharged diesel engine.

摘要

Diesel powered generator sets have traditionally been and remain the number-one choice for standby and emergency power systems. As an established engine technology, diesel engines offer better fuel economy, lower life cycle cost, and higher specific power than SI engines. The combustion process in diesel engines occurs due to the auto-ignition of the air/fuel heterogeneous mixture. Understanding the combustion process is essential for the control of different engine parameters to achieve the production targets particularly for best fuel economy and low emissions. The ion current signal provides vital information about the development of combustion of a particular location in the combustion chamber. Meanwhile, the in-cylinder pressure sensor provides information about the global combustion process.;This thesis investigates the characteristics of the ion current signal under different engine operating conditions of a four cylinder Gen-set diesel engine equipped with an electronically controlled common rail injection system. The experiments are conducted at a constant speed of 1800 RPM and a wide range of loads and injection parameters. The effect of each operating parameter on the features of the ion current signal, as well as its amplitude, timing and phase shift relative to the RHR (rate of heat release), are determined.