Part load characteristics of a DI diesel engine achieving HCCI mode of combustion with air preheating

Abstract

The study focuses on the effect of diesel vapour induction on the engine performance and to try and achieve Homogeneous Charge Compression Ignition (HCCI) mode of combustion in the engine. An existing Direct injection CI engine is modified to work as an HCCI engine by using a shell and tube heat exchanger which aids in the production of diesel vapour by utilising energy of exhaust gas. Different readings are taken for 50% and 75% load conditions. The effect of preheating of air is analysed by heating the inlet air by using a coil type heater. Preheating improved the brake thermal efficiency and brought down CO and HC emissions however it slightly increased NOx emissions. Induction of vapour was continued till the point where engine started to knock. Preheating of vapour was limited to 65°C due to continuous increase in NOx emissions. The best operating condition for each load was calculated and finally the optimum condition for the operation of HCCI engine was determined. © IAEME Publication.