Effect of manifold injection of 1‐hexanol on a reactivity controlled compression ignition engine fuelled with neem oil methyl ester blend

Abstract

AbstractThe novelty of this research aims to attain low‐temperature combustion with the help of reactivity controlled compression ignition (RCCI) in a single cylinder, four‐stroke diesel engine by premixing the low reactivity fuel (LRF) such as 1‐hexanol with air in the intake manifold along with high reactivity fuel (HRF) such as neem oil methyl ester in the volumetric ratio of 80:20 (B20) as a primary fuel. HRF has been utilized as a primary fuel through the main injector along with the manifold injection of LRF fuel through a secondary injector at various energy shares, such as 10%, 20%, 30%, and 40%, and the fuel combinations were designated as B20HI10, B20HI20, B20HI30, and B20HI40. The readings were noted from no load to full load and the experiment showed that the brake thermal efficiency (BTE) was increased in RCCI mode up to 30% 1‐hexanol share compared with B20 due to its better combustion, which was evident by higher heat release rate (HRR); beyond 30%, there was a drop in BTE due to the reduction in pilot fuel quantity. Oxides of nitrogen and smoke were significantly reduced for all combinations in RCCI mode, whereas hydrocarbon and carbon monoxide emissions were increased substantially. A substantial increase in peak pressure and HRR was noticed in RCCI mode compared with conventional mode due to its better homogeneity and prolonged ignition delay. From the findings, this research suggests that B20‐1‐hexanol combinations in RCCI mode can be an attractive replacement for diesel fuel.