- Category Technical paper
- Related event International Congress : SIA Powertrain - Rouen 2014 - 21 & 22 May 2014
- Edition SIA
- Date 05/21/2014
- Author M. Lecompte, S. Raux - IFP Energies Nouvelles
- Language English
Type PDF file (2.6 Mo)
(Downloadable immediately on receipt of online payment)
- Number of pages 7
- Code R-2014-02-34
- Fee Free
The selective catalytic reduction (SCR) based on urea water solution (UWS) is an effective way to reduce nitrogen oxides (NOx) emitted from engines. The high potential offered by this technique makes it a promising way to meet the future stringent exhaust gas legislation.
UWS is injected into the exhaust upstream of a SCR catalyst. The catalyst works efficiently and durably if the spray is completely vaporized before entering and thoroughly mixed with the exhaust gases. Ensuring complete evaporation and an optimum mixture distribution in the exhaust line is challenging, especially with close-couple housing of the SCR catalyst.
Numerous parameters affect the degree of mixing : urea injector technology, internal flow field (aerodynamics), injector location, mixing devices .... In order to quantify mixture quality (vaporization, homogeneity) on entry of the SCR catalyst, it is necessary to employ non-intrusive optical diagnostics techniques. Such techniques can first of all enable a detailed characterization of the UWS spatial distribution upstream of the SCR catalyst. The capability to quantify urea mixture distributions in representative exhaust geometries will ultimately aid the development and performance of SCR systems.
Our experimental tools permit to quickly qualify a technical definition of a SCR exhaust line. The aim of this work is to study the potential of a new compact SCR system in order to optimize the vaporization of UWS and its mixing with the exhaust gases before the SCR catalyst. Experimental results obtained on an engine test bench are presented and discussed.