Effect of acetylene addition in safflower biodiesel fueled CI engine–an experimental study

Abstract

ABSTRACT The aim of the current study is to study the effect of acetylene addition inducted with intake air with safflower biodiesel (SME) as fuel in single cylinder Compression Ignition (CI) engine. Replacement of diesel with SME led to inferior combustion as a result of high viscosity and density. Acetylene was inducted along with intake air in the inlet manifold at various mass shares with diesel and SME as fuel. All the experiments were conducted at 50% and 100% load condition with different acetylene mass shares until knock limit. Tests were conducted until the knock limit was identified at each load with acetylene induction. Acetylene induction improved the brake thermal efficiency (BTE) with both diesel and SME at 100% load, and the improvement was proportional to the increase in acetylene energy share. BTE was improved by 6.6% and 14.3% for maximum acetylene share with diesel and SME, respectively, while the improvement was not significant at 50% load. SME emitted higher NOx in comparison to diesel at both the load conditions and further increased with acetylene induction. While smoke was reduced with SME and further reduced with addition of acetylene at all the loads. HC, CO, and CO2 emissions were lowered with acetylene addition, and maximum reduction of all these three emissions were observed at maximum knock limit. From the experimental study, it is concluded that poor performance of SME was improved with acetylene addition and the BTE of SME with peak acetylene mass share of 10.8% is similar to diesel. Hence, the combination of biodiesel and acetylene can replace diesel in CI engine to match the emission norms.