Transient Control Strategies for an Engine with an Exhaust Treatment System to Meet Future Emissions Standards, 03-R9526Printer Friendly Version
Inclusive Dates: 01/01/05 01/01/07
Background - Manufacturers of diesel-powered light-duty vehicles in the United States and Europe face stringent emissions regulations in the future. A lean NOx trap (LNT) is the likely exhaust treatment device for NOx control in the U.S., while diesel particulate filters (DPF) are a certainty for particulate matter (PM) control. LNTs must be regenerated periodically to purge the nitrate emissions stored under lean operation. The regeneration process requires the diesel engine to be run richer than stoichiometric conditions. Regeneration under relatively steady-state conditions is a common practice in development efforts even though steady-state conditions are not common in real-world driving.
Approach - The objectives of this project are to develop and demonstrate combustion technology and control strategies to accommodate transient operation of a diesel engine that uses a lean NOx trap (LNT)-based, four-way catalyst system with a specific focus on the following:
A Renault G9T-600, a modern diesel engine that complies with the Euro-IV European emissions regulations, is used in this project. This 2.2-liter engine was instrumented and installed in an SwRI emissions laboratory, and an SwRI-designed rapid prototyping electronic control system (RPECS®) is used to replace the production electronic control unit. Strategies for obtaining rich operation before and during a transient event have been proposed.
Accomplishments - The following objectives have been accomplished in this project.