Exhaust Emission Study of Turbocharged CI Engine under Transient Operation Using BS IV and BS VI Diesel Fuel

Abstract

The stringent laws and regulations concerning the vehicle emissions have compelled the automotive sector and pollution boards to adapt to more advanced engine design and after treatment devices. In addition, the testing facilities have also been upgraded from time to time in order to comply with the latest emission regulations. The diesel fuel has been the prime mover of transportation and power generation sector in the world for over a century. The emission study of engine in real time is crucial to interpret the behavior and effect of fuel oil and lubricant on the engine performance and emissions. India from past few years has been following the emission regulations of Europe, that is, Euro norms, and currently Euro-4 compliant vehicles are manufactured and running all over the country. A transient test schedule, named European Transient Cycle (ETC) was operated on the turbocharged diesel engine with use of ultra low sulfur diesel. A comparison of engine performance and emissions with Bharat Stage BS IV and BS VI diesel fuel was drawn. The concentration and mass of regulated emissions such as nitrous oxides, total hydrocarbons and carbon monoxide were calculated and compared for both the diesel fuels. Particulate matter emissions comprising of fine and ultrafine particulates were measured with full flow dilution method to calculate the particle number concentration and mass from the engine exhaust. The BS VI diesel showed better results with improved brake specific fuel consumption, and reduced particle number (PN) emissions and particulate mass (PM) when compared to BS IV diesel fuel. Specific emissions measured in g/kWh indicate the emissions produced per kWh of electricity (work) produced by the engine. In the following years, portable emission measurement systems (PEMS) will become more common as real time transient results can be obtained during the field trial of vehicles with portable and less bulky equipment required. As the present dilution and conditioning equipments require a very large space and investment, emission systems in the future are expected to become portable.