Modeling and experimental analysis of exhaust gas temperature and misfire in a converted-diesel homogeneous charge compression ignittion engine fuelled with ethanol

Abstract

Homogeneous charge compression ignition (HCCI) and the exploitation of ethanol as an alternative fuel is one way to explore new frontiers of internal combustion engines with an objective towards maintaining its sustainability. Here, a 0.3 liter singlecylinder direct-injection diesel engine was converted to operate on the alternative mode with the inclusion of ethanol fuelling and intake air preheating systems. The main HCCI engines parameters such as indicated mean effective pressure, maximum in-cylinder pressure, heat release, in-cylinder temperature and combustion parameters, start of combustion, 50% of mass fuel burnt (CA50) and burn duration were acquired for 100 operating conditions. They were used to study the effect of varying input parameters such as equivalence ratio and intake air temperature on exhaust gas emission, temperature and ethanol combustion, experimentally and numerically. The study primarily focused on HCCI exhaust gas temperature and understanding and detecting misfire in an ethanol fuelled HCCI engine, thus highlighting the advantages and drawbacks of using ethanol fuelled HCCI. The analysis of experimental data was used to understand how misfire affects HCCI engine operation. A model-based misfire detection technique was developed for HCCI engines and the validity of the obtained model was then verified with experimental data for a wide range of misfire and normal operating conditions. The misfire detection is computationally efficient and it can be readily used to detect misfire in HCCI engine. The results of the misfire detection model are very promising from the viewpoints of further controlling and improving combustion in HCCI engines.