Search Results

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms along with top performance for vehicle, a good strategy should be incorporated to control system out NOx emissions and soot regeneration. Extruded Vanadium catalyst is deployed for this passive regeneration system with DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter) and SCR (Selective Catalyst Reduction), where the amount of catalyst loading in DOC plays an apex role in deciding conversion efficiency of SCR and passive regeneration capabilities. This study mainly focuses on the impact of catalyst loading of DOC over SCR efficiency. NO2 to NOx ratio should be close to 0.5 for optimum conversion efficiency of SCR. Catalyst loading in DOC decides the amount of NO2 coming upstream to SCR.

Diesel exhaust is a complex mixture of combustion products of diesel fuel, and the exact composition of the mixture depends on the nature of the engine, operating conditions, lubricating oil, additives, emission control system, combustion parameters and fuel composition. In a diesel engine, NOx (NO & NO2) and PM (Particulate Matter) are the most critical constituents for the emission legislation. In order to control the PM emission of diesel engine and comply with increasingly stringent exhaust legislation, more information is required on the components and genesis of PM. In general, PM from diesel engines is classified into two fractions: Insoluble Organic Fraction (ISOF) and Soluble Organic Fraction (SOF). In this experimental study, a series of 13 mode ESC cycle were run on a light duty diesel engine after optimization of combustion parameters (Injection Pressure, Injection Timing, Multiple Injections, EGR rate, etc) in successive tests and PM component was analyzed.

Future emissions regulations like BSIV and above in India, Diesel engine manufacturers are forced to find complex ways to reduce exhaust gas pollutant emissions, in particular NOx and particulate matter (PM). Exhaust gas recirculation (EGR) into the engine intake is an established technology to reduce NOx emissions. The distribution of EGR in each cylinder plays vital role in combustion process and hence it will affect exhaust emissions. The influence of EGR mixture design and its effect on distribution across the cylinder has significant impact on the NOx-PM trade-off which is studied on light duty direct injection diesel engine. A simulation and experimental study of EGR mixer design is conducted to explain this effect and the distribution of EGR across the cylinder at different EGR flow rate.

Exhaust gas recirculation (EGR) is one of the most effective methods for reducing the emissions of nitrogen oxides (NOx) of diesel engines. EGR system has already been used to mass-produce diesel engines, in which EGR is used at the low and medium load of engine operating condition, resulting in NOx reduction. In order to meet future emission standards, EGR must be done over wider range of engine operation, and heavier EGR rate will be needed. It is especially important for EGR to be done in a high engine load range since the amount of NOx is larger than the other engine operation conditions. EGR systems adapted to the diesel engines of trucks usually recirculate exhaust gas utilizing the pressure difference between upstream part of the turbocharger turbine and downstream part of the compressor. The venturi throat diameter plays the vital role for the flow of EGR across the exhaust and intake.

The implementation of stringent BSVI norms from April 2020 has greatly revolutionized the automobile industry. With the plan for implementation of more stringent BSVI OBD-II norms from April 2023, in place, meeting legislative limits, particularly with CI engines, will be a challenge. The major challenge is the reduction in nitrogen oxides (NOx) which necessitates a selective catalytic reduction (SCR), together with effective calibration, to maintain the conversion efficiencies at the highest possible levels. The conversion efficiency is majorly dictated by temperature and exhaust mass flow. Hence, optimization of thermal management modes are very important. This is achieved by a close-coupled diesel oxidation catalyst (DOC).