Performance and Emission Analyses of Acetylene Dual Fuel Engine

Abstract

Fossil fuels are exhausting day by day at a very faster rate due to excessive demand for energy. Diesel engines are important prime movers used in different industries. When liquid petroleum fuels are burnt in diesel engines they emit harmful exhaust emissions which pollute the environment and may cause severe chronic diseases. Hence to mitigate over-dependency of crude oil and to protect the environment from harmful emissions, different engine experts and scientists have proposed dual fuel combustion technology to utilize low emissions renewable gaseous fuels without compromising its performance. Most of the work in the literature concentrate on utilizing gaseous fuels such as CNG, LPG, biogas, and hydrogen whereas very little quantum of work has been done to utilize acetylene in the IC engine. The higher flame velocity, high auto-ignition temperature, and high calorific value are the important combustion properties of acetylene which makes it more advantageous in CI engine than the available feedstock. The acetylene can be easily produced from calcium carbonate and water. Hence, the author has considered acetylene as a primary fuel in the present study and diesel as a pilot fuel in the modified CI engine. In this experimental investigation, the author has optimized the flow rate of acetylene by analyzing the performance and emission characteristics of the acetylene fuelled diesel engine at different loads and finally, the obtained results were compared with the neat diesel. The acetylene was inducted at a different gas flow rate of 2 LPM, 3 LPM, and 5 LPM. The results show that when acetylene induction takes place at 2 LPM, the brake thermal efficiency (BTE) increases by 1.4 % at full load during dual fuel mode compared to neat diesel. Brake specific energy consumption (BSEC) increases during acetylene induction whereas carbon monoxide, hydrocarbon, and smoke decrease particularly at medium to high engine loads this may be due to homogenous charge mixture formation, leading to stable combustion. However, there is a slight increase in oxides of nitrogen emissions, which may be due to higher flame speed causing uncontrolled combustion at peak loads relative to baseline diesel.