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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).

The demand for reduced pollutant emissions has motivated various technological advances in commercial diesel engines. The challenge for the direct injection diesel engines today is to reduce harmful emissions of diesel engines, such as Particulate Matter (PM) and Nitrogen oxides (NOx), and enhance the fuel efficiency and power. To meet this challenge, more accurate control of injection parameters such as the injection timing, injection rate, and injection quantity is required. A comprehensive study is carried out in order to better understand combustion behavior in a direct injection diesel engine working under different injection strategies particularly with post and pre-injections and number of injection. The objective of the study described in this paper is to explore the potential of multiple injection patterns with a common rail system in light duty diesel engines.

Development works with metallic open channel PM Filter Catalyst in conjunction with diesel oxidation catalysts and Pre Turbo Catalyst (PTC) on Diesel Cars and Commercial Vehicles with CRDi engines have been reported earlier. These results show that PM conversion efficiency of the order of 40 % can be achieved with PM Filter Catalyst on passenger car diesel engines with continuous regeneration capability. Recently experiments were carried out on a DI engine having distributor type rotary fuel injection equipment with electronic control, turbocharged and inter-cooled, calibrated for BS-III (EURO-III) emissions, with an aim to explore the potential of oxidation catalyst and the PM Filter Catalyst to meet BS-IV (Euro-IV) emission norms. These experiments were carried out with 500ppm sulphur diesel. The results of the tests are presented in this paper. It is seen that with only an oxicat of low level catalyst loading, PM (soluble organic fraction) can be brought down by 20%.