Abstract
Understanding the spray/wall interaction of urea water solution in automotive selective catalytic reduction (SCR) of NOx is crucial for robust system performance. The spray impingement of aqueous urea solution on walls at temperatures from 120 to 420 ∘C is investigated experimentally by using high-speed and infrared thermographic recordings. To evaluate wall wetting and spatially resolved heat transfer, the evaporated mass fraction during spray/wall interaction is described quantitatively through an energy balance. Heat transfer at different wall temperatures shows typical non-linear characteristics analogous to those known from pool boiling experiments (Nukiyama boiling curve). The performed extensive parameter study on the influence of injected fluid, injection duration, injection pressure, wall thickness and wall material reveal significant shifts of the boiling regime boundaries and the related characteristic temperatures, e.g. temperature of critical heat flux and Leidenfrost temperature. These basic findings help to understand spray/wall interaction phenomena and give hints for improvement of automotive SCR system design by taking into account the change of the injection system parameters and the choice of advantageous wall material properties.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.