Development of DME-Fueled Diesel Engine for Light-Duty Trucks Meeting Japan's 2009 Emissions Regulations

摘要

DME fuel has been attracting attention as an alternative fuel for diesel engines. DME has a high cetane number and compression ignition capability. This enables a high thermal efficiency comparable to conventional diesel engines. Moreover, DME creates no smoke or sulfur oxide. However, NOx emissions still remain a problem under stringent exhaust emissions regulations. To meet the severe NOx regulations and to aid the development of alternative fuels for diesel engines, a DME-fueled diesel engine (base engine: 4HG1T supplied by Isuzu Motors Limited) for use in light-duty trucks has been developed using a jerk type in-line DME injection system. This engine meets Japan's 2009 emissions regulations. Adopting technology to reduce exhaust emissions, such as a large volume EGR system with air-throttled and inter-cooled turbo-charging, the National Traffic Safety and Environment Laboratory and Bosch Corporation has demonstrated a low-emission engine that reduces NOx emissions to about 50% (0.37 g/kWh) of the level of the 2009 emissions regulations ( < 0.7 g/kWh) without a NOx reduction catalyst system.