NOx-Conversion Comparison of an SCR-Catalyst Using a Novel Biomimetic Effervescent Injector on a Heavy-Duty Engine 2019-01-0047
Over 10 000 premature deaths can be saved by reducing the local NOx emissions from diesel engines and this numbers increases even with the emission regulations today. Exhaust after-treatment systems have become an important research topic in order to decrease this growing problem. One important factor in the near future is to reduce the overall emissions by implementing real-driving emissions that make the SCR-Technology even more challenging.
The SCR-Technology dosing an aqueous Urea solution into the flow of exhaust gases upstream of an SCR-Catalyst in order to convert the harmful NOx emissions to Nitrogen and Water. To enable the reactions to occur the Urea solution needs to be fully evaporated before it reaches the catalytic surface and to enhance this process aggressive mixer plates and long pathways is a standard on the market leading systems. The novel biomimetic effervescent injector, that is inspired by the efficient spray mechanism of the Bombardier Beetle, increases the temperature of the Urea solution inside a constant volume chamber to above its saturated vapour pressure. At the time of injection, an electromagnetic controlled outlet valve opens and the heated fluid quickly breaks-up into very small droplets that inject with high velocity into the exhaust stream.
This study compares the difference between this novel technology and the market-leading standard with and without the aggressive mixer plate installed. The novel biomimetic injector shows great potential with significant higher conversion rates and lowers ammonia slip compared to the market-leading injector on a heavy-duty engine.
Peter Larsson, Paul Ravenhill, Per Tunestal
Lund University, Lysander R & D Ltd.
International Powertrains, Fuels & Lubricants Meeting