Experimental investigation on pressure and heat release HCCI engine operated with chicken fat oil/diesel-gasoline blends

Abstract Low-temperature combustion is the individuality of Homogenous charge compression ignition (HCCI) engines where the combustion is achieved at the temperature lower than the temperature at which NOx is formed. By achieving this type of combustion in the engine it is possible to reduce the formation of Thermal NOx and PM. But on the other hand, the performance. In this current study, the combustion parameters of the engine are studied by varying the input parameters of the engine that has been modified to run in HCCI mode. The engine is fuelled with the blends of chicken fat oil biodiesel (CFOB) and gasoline. In the present work, the engine is tested for combustion properties such as in-cylinder pressure, heat release rate and the rate of pressure rise for different blend ratios. The ignition delay has persistently elevated for an increase in the gasoline concentration in blends. Also, the knock is consistently seen at higher engine loads with the blends of gasoline and diesel as well as gasoline with biodiesel. Diesel fuel exhibited lower peak pressure whereas, pure biodiesel exhibits higher peak pressure and the peak cylinder pressure within the engine at higher load varies from 40 to 75 bar. On comparing the heat release rate, the diesel fuel exhibit lower heat release as compared to fuel blended with chicken fat oil. Due to the delay in the start of low-temperature reactions the peaks on the rate of heat release is reduced. During higher engine load conditions, the engine seizes to operate in HCCI mode instead it operates in a conventional pattern which is clearly proved by the heat release curves obtained for the indicated pressure and crank angle data of the particular operating mode of the engine.