Development of Clean Diesel Demonstration Vehicle with Alternative Combustion and Multivariable Control System, 03-R9636Printer Friendly Version
Inclusive Dates: 07/01/06 01/02/08
Background - SwRI has been studying the use of highly dilute combustion modes such as low temperature combustion (LTC) and premixed controlled compression ignition (PCCI) for reducing engine-out NOx and PM for many years. These combustion modes have demonstrated the potential for large reductions in NOx and PM, especially at low engine loads without severe fuel economy penalties. However, maintaining good combustion quality (stability and noise) during transient operation has remained a challenge. This project was concerned with exploring the collection of parameters that could be used to maintain good combustion. Also, the engine-out NOx emissions were measured over a European driving cycle to assess the potential of meeting a moderately severe emissions standard (Euro V).
Approach - A 2.2 liter Euro IV diesel vehicle was used to perform the following project objectives:
Accomplishments - Using injection timing as the combustion control knob, a preliminary correlation was found between injection timing and in-cylinder oxygen concentration when similar compression temperatures were obtained. This correlation is illustrated in Figures 1 and 2.
In relation to the control logic review and modifications, the following accomplishments were achieved: