Approximate Exhaust Gas Recirculation rate required to reduce engine-out NOx to Tier III limit without urea.
Formula
$$ \text{EGR}% \approx 35 \cdot \sqrt{1 - \text{NO}_x^\text{target} / \text{NO}_x^\text{base}} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $\text{NO}_x^\text{base}$ | Engine-out NOx at 0 % EGR | g/kWh | NOx Technical File |
| $\text{NO}_x^\text{target}$ | Tier III limit | g/kWh | MARPOL Annex VI Reg 13 |
Sources
- MAN ES - EGR Technical Paper.