Progress in the development of Tier 2 light-duty diesel vehicles

摘要

The U.S. Environmental Protection Agency (U.S. EPA) has been conducting a test program to evaluate efforts to bring light-duty diesel vehicles into compliance with U.S. Federal Tier 2 Light-duty Emission Standards. Between April 2002 and October 2003, five advanced prototype light-duty diesel vehicles equipped with NO{sub}x adsorption catalysts, PM-traps, and diesel oxidation catalysts were tested at the U.S. EPA’s National Vehicle and Fuel Emission Laboratory (NVFEL). The vehicle testing was conducted using low-sulfur (<15 ppm) diesel fuel. All of the tested vehicles demonstrated the considerable progress recently made by vehicle manufacturers and systems integrators in applying advanced NO{sub}x and PM emission control technology to light-duty diesel vehicles in anticipation of the U.S. Light-duty Tier 2 emission standards. PM emissions for all of the vehicles were well below the Tier 2 Bin-5 emission levels. The most recently tested vehicle demonstrated intermediate-useful life (50,000 miles) PM, NO{sub}x, and NMHC emissions at or below the Tier 2 Bin-5 levels. This paper represents an early survey of emissions from the first generation of prototype clean diesel vehicles.