Advancing combustion technologies and alternative fuels in hybrid electric vehicles: a pathway to high-efficiency, low-emission propulsion systems

Abstract

In the pursuit of reducing carbon emissions and enhancing fuel efficiency, the integration of advanced combustion technologies and alternative fuels in internal combustion engines (ICEs) remains pivotal, especially when paired with electrified powertrains. This study offers a comprehensive analysis of cutting-edge combustion strategies—Gasoline Direct Injection (GDI), Gasoline Compression Ignition (GCI), and Low-Temperature Combustion (LTC)—and their transformative potential in hybrid electric vehicles (HEVs). Through a detailed examination of these technologies, we assess the thermodynamic optimizations achieved via variable valve timing, variable compression ratio, and cylinder deactivation systems. Additionally, the study investigates the viability of alternative fuels, including compressed natural gas (CNG), liquid petroleum gas (LPG), biodiesel, and hydrogen, as cleaner and more efficient energy carriers. The synthesis of these technologies with HEV platforms not only addresses emission regulations but also pushes the boundaries of thermal efficiency. We provide a critical evaluation of the hybridization benefits, focusing on fuel consumption reductions, particulate matter (PM) mitigation, and overall system efficiency improvements. By coupling multi-mode combustion with electrification, this work underscores a promising trajectory toward achieving near-zero emissions in both light and heavy-duty vehicle sectors. Furthermore, this study offers insights into future propulsion architectures, advocating for a synergistic approach between advanced ICE technologies and electric powertrains to meet stringent global climate targets.