Investigation on Effect of Design Parameters on Engine Performance and Emission Characteristics Fuelled with Cashew Nut Shell Biodiesel Blends

Abstract

Energy security, high crude oil prices and air quality have compelled researchers to find alternate fuels to diesel. In recent years, research has been conducted to use biodiesel as a fuel since the characteristics of biodiesel are similar to diesel. Among the various non-edible oils, cashew nut shell liquid biodiesel is chosen for this study since it is a low cost fuel and its properties are similar to diesel i.e., calorific value of 38,400 kJ/ kg and cetane number of 50. Though cashew nut shell liquid is a waste product, using it as a resource for biodiesel production is still at an early stage, and its usage in a diesel engine is yet to be explored. For effective use of this biodiesel, fuel modification such as blending with diesel and additives and adjustment of injection parameters such as injection timing and split injection are required. It is observed that EGR and retardation of injection timing are capable to reduce oxide of nitrogen (NOx) emissions due to reduction in cylinder temperature. However, they can possibly increase smoke and HC emissions. Split injection improves the air fuel mixture that leads to reduction in smoke and hydrocarbon emissions. Hence, the use of split injection strategy along with EGR and retarded injection timing may have a potential to reduce smoke, HC and NOx emissions along with improved engine performance as compared to conventional injection. Based on the literature survey, it is observed that there is ample scope to analyze the engine performance and emission characteristics with the combination of all these parameters specifically when high viscous oil such as cashew nut shell biodiesel blends are used as fuel. Thus, the combination of injection strategies (split injection, injection timing) and EGR are implemented and their effect on performance and emission characteristics of engine is investigated. The experiments are conducted on a twin cylinder, water cooled, CRDI diesel engine. The various injection parameters such as injection timing, split injection percentage...