In-Cylinder Diesel Particulate and NO_x Control, through Mechanical Fuel Injection Strategy to Achieve CEV BSIII Emission without EGR

摘要

The environmental impact of internal combustion engines has led to increasing governmental regulations regarding the emissions and fuel economy performance of internal combustion engines. The DI Diesel engines, having the evident benefit of a higher thermal efficiency than all other engines, have served for both light- duty and heavy-duty vehicles. But, direct injection diesel engines emit more particulates and oxides of nitrogen than their counterpart and that is a challenge. The NO_x+HC limits for CEV BSIII regulations is 4.00 g/Kw-Hr,3.8 g/Kw-Hr with deterioration factor[DF] against the 10.50 g/Kw-Hr of CEV BSII regulations, which is over 60% reduction in gaseous emissions. Now after this stringent targets defined it is essential to understand the NO_x formation. There are different independent variables or the engine operating parameters for NO_x reduction like injection pressure, injection timing, injection duration, piston bowl geometry, compression ratio, EGR(cooled/hot), pilot injection(which is needs electronic fuel injection system), SCR, injection rate shape, injector nozzle geometry, air/fuel ratio etc. Another approach to reduce the NO_x emission is the exhaust gas recirculation [EGR] either hot or cold loop. However it results in higher soot loading, degradation of lubrication oil, enhanced engine wear, more on the power cylinder components. Further to this EGR leads to additional engine packaging exercise & which is time consuming. Interchangeability on the given end application like wheel loaders, earth movers, excavators with reference to existing packaging is difficult to adopt as well. In this paper, it gives the experimental validation along with typically the high speed data acquisition [HSDA]. The engine configuration used for this experimental validation was turbo charged intercooled with the centrally, vertically mounted injector on the 6 cylinders with 4 valve per cylinder. Paper highlights the approach to identify solution opportunities with the in cylinder combustion by using best of knowledge in the combustion system design. It outlines the strategic advantage of using conventional FIE systems suitable for end user in-terms of cost and aftermarket support and engineering to achieve the objective.