International Journal of Applied Engineering Research

The advent of stringent emission norms and depletion of fossil fuel resources led the engineers to work out new combustion technologies to substantially reduce harmful emission and to improve the overall efficiency of an IC Engine. Factors to be considered while designing a new combustion process are higher compression ratio, lean homogeneous air fuel mixture and complete combustion and instantaneous combustion, which leads to Homogeneous charge compression ignition (HCCI). HCCI is a clean and efficient combustion process. In this experiment we analyze the performance and emission characteristics of HCCI engine operating in premixed charge compression ignition (PCCI) mode assisted with a secondary pilot injector as combustion initiator located at the inlet manifold. Experiments were conducted in a modified single cylinder water-cooled diesel engine, employing our conceptual system known as transient state fuel induction. Here we use diesel, petrol and bio-diesel (jatropha) as the fuels at different mixing ratios. The engine wear and tear and emissions have also been found decreasing with the use of bio-diesel when compared to vegetable oil. Variable valve actuation (VVA) has been proven to extend the HCCI operating region by giving finer control over the temperature-pressure-time history within the combustion chamber. The observations had proved to have increase in brake thermal efficiency with reduced emissions.