Experimental Investigation of Novel Ammonia Mixer Designs for SCR Systems IFP Energies Nouvelles

Format:

Conference/Event

Author/Creator:

Schiffmann, Schiffmann, author.

Contributor:

Laget, Olivier

Lecompte, Matthieu

Conference Name:

WCX World Congress Experience (2018-04-10 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2018

Summary:

AbstractMeeting Euro 6d NOx emission regulations lower than 80mg/km for light duty diesel (60mg/km gasoline) vehicles remains a challenge, especially during cold-start tests at which the selective catalyst reduction (SCR) system does not work because of low exhaust gas temperatures (light-off temperature around 200°C). While several exhaust aftertreatment system (EATS) designs are suggested in literature, solutions with gaseous ammonia injections seem to be an efficient and cost-effective way to enhance the NOx abatement at low temperature. Compared to standard SCR systems using urea water solution (UWS) injection, gaseous NH3 systems allow an earlier injection, prevent deposit formation and increase the NH3 content density. However non-uniform ammonia mixture distribution upstream of the SCR catalyst remains an issue. These exhaust gas/ NH3 inhomogeneities lead to a non-optimal NOx reduction performance, resulting in higher than expected NOx emissions and/or ammonia slip. Thus, efficient mixers upstream of the SCR are crucial for the overall EATS performance. In the experimental study reported in this article, planar laser induced fluorescence (PLIF) is used to quantify mixing performance of four novel CFD optimized static mixers in an optically accessible flow bench. The variation of boundary conditions and the change of exhaust line configurations (e.g.w/wo DOC upstream, w/wo DPF downstream) show a major effect on the mixing process and subsequently the homogeneity of the ammonia-exhaust gas mixture (for example: drop in uniformity index from UI=0.95 to UI=0.60 for a blade mixer design). This points out the need to purposefully design and optimize static mixers for a specific exhaust line configuration

Notes:

Vendor supplied data

Publisher Number:

2018-01-0343

Access Restriction:

Restricted for use by site license