Enabling simultaneous reductions in fuel consumption, NOx, and CO2 via modeling and control of residual-affected low temperature combustion

Abstract

There are currently 200 million vehicles on the road in the United States alone, resulting in the consumption of 600 billion liters of fuel each year. With annual growth rates of vehicle sales and miles driven at 0.8 and 0.5%, respectively, our domestic challenges are no less than two-fold: increasing dependence on foreign sources of transportation fuel [1] and the release of significant amounts of greenhouse and smog-generating chemicals, including CO2 and NO x[2]. There is a solution-by integrating advanced internal combustion engines (ICEs) on hybrid powertrains there is a wonderful opportunity to realize a 50% reduction in fuel consumption by 2020 (Heywood et al. 2003). A significant step to meeting this goal will be the implementation and coordinated control of a number of exciting, evolving engine technologies: direct, multi-point fuel injection; flexible intake and exhaust valve actuation (i.e., variable valve actuation (VVA)); real-time, production-viable in-cylinder sensing/estimation; cooled exhaust gas recirculation (EGR), and dual-stage variable geometry turbocharging. Exploring the most capable and cost-effective mix of these technologies is a key challenge in the ongoing effort to deliver the most effective engines to end-users (both individuals and industry). One particularly promising approach leveraging these advances, residual-affected low temperature combustion (LTC), exhibits a substantial increase in efficiency by 10-15% compared to spark-ignition (SI), and has NO x and soot levels that are dramatically lower than either diesel or SI. However, to date LTC has been difficult to practically implement because it has no specific initiator of combustion and is subject to cyclic coupling through the temperature of reinducted or trapped combustion gases. This chapter details the merits and history of residual-affected LTC, and the approaches being pursued in academia and industry to meet the aforementioned hurdles to practical on-road implementation. © 2008 Springer Science+Business Media B.V.