Bhosale, S., Suresh, R., and Ray, D., "Cost Efficient Bharat (Trem) Stage IV Solutionsfor TractorEngines," SAE Technical Paper 2015-26-0092, 2015, doi:10.4271/2015-26-0092.
India's high Air Pollution level is the focus of discussions as we grow. Plans to combat this menace and implement the latest Technologies are gathering pace. The increasingly stringent emission legislations provide a continuous challenge for the non-road market. Tractor manufacturers are evaluating the need for cost-effective technology to meet upcoming stringent emissions targets. Simply following global approach may not work for Indian market considering the customer usage pattern & perceptions. With an anticipation of upcoming emission norms being based on US-EPA TIER-4 final up to 75 Hp, major technology up gradation is expected for farm equipment sold in India. The enormous diversification of engines within the different power classes as well as the operation specific requirements regarding various duty cycles, robustness and durability, requires specific solutions to meet these legal limits.The technology solutions are varying from advanced in-cylinder combustion strategies to sophisticated exhaust after-treatment technologies. Generally, the proven technology concepts such as Common Rail System (CRS), efficient Turbocharged-Intercooled (TCI), and controlled cooled EGR along with DOC-DPF in after treatment are used for such stringent emission controls. However, this approach will substantially increase engine cost in addition to the packaging challenges for the existing vehicle layouts.With an aim of providing cost efficient technologies with minimum changes on current vehicle platforms, the potential of Natural Aspirated engine is explored. For a chosen capacity NA engine, an approach of meeting various power density applications with combination of Hot or cold EGR is demonstrated. However NA engines will have limitations for high power density tractor engines and hence technology approach for TCI engines is also discussed.This publication shows the technical feasibility, the boundaries and challenges of such an application, as well as a trade-off between power density and technology for tractor engines in this segment.