Quantitative measurements were made of NOx feedgas emissions during transient engine operation as the response time of an EGR system was progressively-degraded. For a simple acceleration-cruise-deceleration engine speed/torque versus time trajectory, it was found that the NOx emissions were higher during acceleration and lower during deceleration than corresponding values predicted from steady-state mapping data. The magnitude of the differences, as well as the total mass of NOx integrated over the speed/torque trajectory, all increased as the EGR response time was increased. Using a simple dynamic EGR model, NOx feedgas emissions were predicted for engine operation with a production EGR system over a 128 second portion of the FTP CVS cycle. The NOx feedgas predictions were shown to be in excellent agreement with actual emission measurements.
The Effect of EGR System Response Time on NOx Feedgas Emissions during Engine Transients
Sae Technical Papers
SAE International Congress and Exposition ; 1985
1985-02-01
Aufsatz (Konferenz)
Englisch
A Comparison Between Predicted and Measured Feedgas Emissions for Dynamic Engine Operation
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|The effect of EGR System response time on NOx feedgas emissions during engine transients
Kraftfahrwesen | 1985
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