CNG-HOME operated dual fuel and HCCI engines

Abstract

The looming extinction of fossil fuels and their hazardous environmental impact caused by automotive systems has led to the use of alternative combustion strategies and renewable fuels for IC engines. Conventional CI engines due to their heterogeneous combustion emit large amount of particulate matter and the major concern regarding diesel engine is that high NOx emissions. However this problem can be resolved by using an advanced combustion technology named as Homogeneous Charge Compression Ignition (HCCI). HCCI has potential to substantially reduce particulates and NOx simultaneously and deliver efficiencies comparable to conventional CI combustion. Dual fuel approach is a well-established technique to make use of different types of fuels in diesel engines and the main advantage of such engines is their lower smoke, HC emissions. In the present work, experimental investigations were carried out on a single cylinder four stroke compression ignition (CI) engine fuelled with diesel in single fuel mode and CNG and HOME injection in a modified dual fuel mode AND using HCCI operation mode. Gaseous fuel like CNG was injected into the intake manifold using a suitable injector and Electronic Control Unit (ECU) facilities. From the results obtained, it is observed that HCCI engines yielded better results than dual fuel engines in conventional mode. However, emissions such as NOx and smoke were lower whereas emissions like HC and CO was increased. The NOx and smoke emissions were decreased to about 98% and 90 - 94% respectively.