Experimental studies on cyclic variations in a single cylinder diesel engine fuelled with raw biogas by dual mode of operation

Abstract

In this research work, cycle-by-cycle variations of a single cylinder, diesel engine operated with raw biogas is investigated. The biogas used to run the engine is obtained from food waste and as the composition of 88.10%-CH4 + 11.895%-CO2. To study the combustion characteristics, the naturally aspirated diesel engine is converted into dual mode by inducting the biogas into the intake manifold for different proportions from BG20 to BG60 with a step of 10% is mixed with air (i.e. BG60-60% of biogas by mass) respectively. Combustion parameters are measured and recorded by the means of the data acquisition system (DAQ) for 100 combustion cycle. By determining the parameters such as standard deviation, coefficient of variation and return map, the cycle variability is analyzed. From the experimental result, it is observed that as the engine is operated at higher loads and as the biogas is increased from BG20 to BG60 the cyclic variations for maximum cylinder pressure (Pmax) and indicated mean effective pressure (IMEP) increases. Coefficient of variation of Pmax for BG20 and BG40 is lower by 2.3% and 11.98% as compared to diesel. From time return map, BG40 showed good combustion stability and lesser NOx emission compared to diesel. 2020 Elsevier Ltd