Evaluating the Influence of Exhaust Back Pressure on Performance and Exhaust Emissions Characteristics of a Multicylinder, Turbocharged, and Aftercooled Diesel Engine

An experimental study was conducted to quantify the effects of exhaust back pressure (EBP) on performance and exhaust emissions characteristics of a diesel engine for generator application. The electromechanical system was composed of a commercially available six-cylinder, turbocharged, and aftercooled diesel engine, coupled with a generator rated at 500 kilowatt electrical (kWe) at full load. Experiments were conducted at different operating conditions for high and low EBPs. Exhaust emissions of nitrogen oxides (NO_x), soot, particulate matter (PM), carbon monoxide (CO), and total hydrocarbons (HC) were measured. In addition, thermocouples and pressure sensors were provided at various locations to evaluate the engine performance. Results showed that the brake specific fuel consumption (BSFC) was increased at light loads for high EBP, but no significant difference was observed in BSFC at high loads. It was found that NO_x emission was reduced at all operating loads, but soot and PM were increased with the increase in EBP. HC emission was relatively insensitive with increment of EBP.