Philosophy for Controlling Auto-Ignition in an HCCI Engine

In the automobile industry, engines are mostly 4-stroke engines (intake stroke, compression stroke, combustion stroke and exhaust stroke) and generally there are two kinds of automobile engines: the Otto engine (Spark Ignition, SI) and the Diesel engine (Compression Ignition, CI). These two types of engines will be discussed as well as the most important pollutants they emit. In order to reduce the emission of these pollutants an alternative combustion process is discussed, called the Homogeneous Charge Combustion Ignition (HCCI). The advantages and problems are treated. One of the major problems to be solved is the ignition timing that is spontaneous in contrast with that of the spark ignition and diesel engines. Results from experiments, performed in a mono-cylinder engine, are analysed in order to discuss criteria that should be taken into account before the solution of controlling the auto-ignition can be discussed. The results are subsequently used in order to propose an outline for controlling the autoignition in an HCCI engine.

Keywords: Philosophic outline, compression ignition, auto-ignition, combustion control, parametric study, engine parameters, emission control, HCCI engine, EGR, influence chemical species, indicated efficiency, equivalence ratio, engine speed, auto-ignition characteristics, new technology, green energy.