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In order to meet emission norms, modern day diesel engines rely on methods of in cylinder emission reduction and expensive exhaust after treatment devices. Engine manufacturers across the world are finding it hard to maintain balance between customers' demand for better fuel consumption and obeying the stringent legislative emission regulations. Optimum combination of variables such as piston bowl shape, compression ratio, fuel injection and turbo charging systems precisely matched with engine, Exhaust Gas Re-circulation (EGR) rate etc can result in refined combustion leading to better engine out emissions as well as fuel efficiency. Optimization of piston bowl geometry and EGR rate would require a lot of experiments, which involves cost and time. If the numbers of variants of piston bowl shapes or EGR rates are more, so would be the expensive and require more testing time.

Indian emission norms for stationary Gensets are upgraded from CPCB I to CPCB II. These new emission norms call for a significant change in emission limits. CPCB II emission norms call for 62% reduction in NOx+HC and 33% reduction in particulates for engines above 75 kW up to 800 kW power range compared to existing CPCB I norms. CPCB II norms are more stringent as compared to European Stage IIIA and CEV BS III. To meet equivalent emission norms in US and Europe most of the engine manufacturers have used Common Rail Direct Injection (CRDI) or electronic unit injection as the fuel injection technology. This paper describes mechanical fuel injection solution for meeting CPCB II emission norms on engines between 93 kW up to 552 kW with acceptable fuel consumption values. The paper presents simulation and experimentation work carried out to achieve the norms for the said power ratings.

Development trend in diesel engines is to downsize and develop more power from same size of engine. This requires additional air flow and hence increased boost pressure ratio (BPR). With increased brake mean effective pressure (BMEP), the altitude capability of engine reduces. This paper presents a novel approach to estimate the altitude capability of engine and calculate deration factor. As the altitude above sea level increases, ambient pressure decreases, air becomes thinner. For same altitude, ambient temperature also varies as per seasonal changes. This results in change (reduction) in ambient air density. This reduction has significant effect on turbocharger (TC), Intercooler and engine performance. Beyond a limiting altitude, engine performance shall be compromised to avoid any damage to engine and its components.