An experimental investigation into the combustion properties, performance, emissions, and cost reduction of using heavy and light fuel oils

Abstract

Heavy fuel oil (HFO) is a fuel that can be used in compression ignition engines because of its cheapness and low operating costs. However, heavy fuel oil is not compatible with most diesel engines and combustion systems in use. As a result, there is a decrease in the efficiency of the combustion process. To treat this problem, and for the purpose of using heavy fuel oil, the characteristics of the diesel engine fuel and combustion system were improved in this study. The high viscosity of heavy fuel oil was reduced (before it was introduced into the engine) by adding a suitable heating device in the fuel line. Light fuel oil (LFO) is also blended with heavy fuel oil to reduce the viscosity of the fuel. HFO properties, such as viscosity, density, calorific value, and sulfur content, were determined. A blend called LFO-H20 (80% LFO:20% HFO) was prepared and tested in a single-cylinder diesel engine. This engine performance and exhaust emissions were evaluated using LFO, HFO (70°C), LFO-H20 and LFO-H20 (70°C). The tests were conducted using a one-cylinder test rig, Kirloskar, which is naturally aspirated, direct injection and has maximum speed of 1500 rpm diesel engine. The results showed that the Brake Thermal Efficiency (BTE) for HFO (70°C), LFO-H20 and LFO-H20 (70°C) was (31.21%, 22.5%, and 10.4%) lower than LFO. The Brake Specific Fuel Consumption (BSFC) also increased by about (28.93%, 20.1%, and 10.5%) compared to LFO. The oxides of nitrogen (NOx) were increased at HFO and single blend fuel by about (19.64%, 11.92%, and 7.53%) compared to LFO. In addition, the unburned hydrocarbon (UHC) for HFO (70°C), LFO-H20 and LFO-H20 (70°C) was (42%, 28.7%, and 18.4%) higher than LFO. The CO concentrations increased by (38.4%, 30.6%, and 18%) compared to LFO. Finally, the smoke opacity values of HFO (70°C), LFO-H20 and LFO-H20 (70°C) were increased by (42%, 26% and 17.2%) respectively. The effect of heating tested fuels at a temperature of (70 °C) resulted in decreasing their density and viscosity, which improved the fuel combustion spray characteristics and enhanced the engine performance and emission.