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SCR-catalyst utilisation and mixing comparison using a novel biomimetic flash-boiling injector

Larsson, Peter LU ; Ravenhill, Paul ; Larsson, Lars Uno and Tunestål, Per LU (2018) ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018 2. p.1-7
Abstract

NOx pollution from Diesel engines causes over 10 000 premature deaths annually and the trend is increasing. In order to decrease this growing global problem, exhaust after-treatment systems for Diesel engines have to be improved. The most common SCR systems in the market place inject an aqueous Urea solution, DEF that evaporates prior the catalytic surface of the SCR-catalyst. Due to a catalytic reaction within the catalyst, NOx is converted nominally into Nitrogen and Water. Currently, the evaporative process is enhanced by aggressive mixer plates and long flow paths; these, negatively, create extra exhaust back pressure and cool the exhaust gases decreasing engine and catalyst efficiency. To achieve future emission legislation targets... (More)

NOx pollution from Diesel engines causes over 10 000 premature deaths annually and the trend is increasing. In order to decrease this growing global problem, exhaust after-treatment systems for Diesel engines have to be improved. The most common SCR systems in the market place inject an aqueous Urea solution, DEF that evaporates prior the catalytic surface of the SCR-catalyst. Due to a catalytic reaction within the catalyst, NOx is converted nominally into Nitrogen and Water. Currently, the evaporative process is enhanced by aggressive mixer plates and long flow paths; these, negatively, create extra exhaust back pressure and cool the exhaust gases decreasing engine and catalyst efficiency. To achieve future emission legislation targets SCR efficiency has to be improved especially under low catalyst temperature conditions, plus Ammonia slip has to be avoided as it is now legislated against. Swedish Biomimetic’s novel µMistR platform technology, inspired by the Bombardier Beetle, injects a hot, effervescent, finely atomised, highly dispersed spray plume of DEF into the exhaust stream. This is achieved by raising the temperature of the DEF, in a closed volume, above its saturated vapour pressure. The DEF is then rapidly released creating effervescent atomisation. This study investigates a back to back study of the evaporating and mixing behaviour of the µMistR injector and a class leading DEF injector. The test conditions are with and without a mixer plate and the use of two different flow path designs. Spray distribution across the face of the catalyst is assessed by measuring NOx conversion whilst Ammonia slip is also measured post catalyst. This report describes how the novel µMistR injector significantly increases NOx conversion and catalyst surface usage whilst considerably reducing Ammonia slip.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Boiling, Catalysts, Biomimetics, Ejectors
host publication
Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development
volume
2
article number
ICEF2018-9763
pages
7 pages
publisher
American Society Of Mechanical Engineers (ASME)
conference name
ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018
conference location
San Diego, United States
conference dates
2018-11-04 - 2018-11-07
external identifiers
  • scopus:85060393843
ISBN
9780791851999
DOI
10.1115/ICEF2018-9763
project
Bio-Inspired AUS-32 Dosing and NOx Conversion: using A Biomimetic Effervescent Injector
language
English
LU publication?
yes
id
72caae94-70e3-4a2b-b64a-58e62fdf6cd0
date added to LUP
2018-12-14 14:26:46
date last changed
2023-03-29 15:05:26
@inproceedings{72caae94-70e3-4a2b-b64a-58e62fdf6cd0,
  abstract     = {{<p>NOx pollution from Diesel engines causes over 10 000 premature deaths annually and the trend is increasing. In order to decrease this growing global problem, exhaust after-treatment systems for Diesel engines have to be improved. The most common SCR systems in the market place inject an aqueous Urea solution, DEF that evaporates prior the catalytic surface of the SCR-catalyst. Due to a catalytic reaction within the catalyst, NOx is converted nominally into Nitrogen and Water. Currently, the evaporative process is enhanced by aggressive mixer plates and long flow paths; these, negatively, create extra exhaust back pressure and cool the exhaust gases decreasing engine and catalyst efficiency. To achieve future emission legislation targets SCR efficiency has to be improved especially under low catalyst temperature conditions, plus Ammonia slip has to be avoided as it is now legislated against. Swedish Biomimetic’s novel µMistR platform technology, inspired by the Bombardier Beetle, injects a hot, effervescent, finely atomised, highly dispersed spray plume of DEF into the exhaust stream. This is achieved by raising the temperature of the DEF, in a closed volume, above its saturated vapour pressure. The DEF is then rapidly released creating effervescent atomisation. This study investigates a back to back study of the evaporating and mixing behaviour of the µMistR injector and a class leading DEF injector. The test conditions are with and without a mixer plate and the use of two different flow path designs. Spray distribution across the face of the catalyst is assessed by measuring NOx conversion whilst Ammonia slip is also measured post catalyst. This report describes how the novel µMistR injector significantly increases NOx conversion and catalyst surface usage whilst considerably reducing Ammonia slip.</p>}},
  author       = {{Larsson, Peter and Ravenhill, Paul and Larsson, Lars Uno and Tunestål, Per}},
  booktitle    = {{Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development}},
  isbn         = {{9780791851999}},
  keywords     = {{Boiling; Catalysts; Biomimetics; Ejectors}},
  language     = {{eng}},
  month        = {{09}},
  pages        = {{1--7}},
  publisher    = {{American Society Of Mechanical Engineers (ASME)}},
  title        = {{SCR-catalyst utilisation and mixing comparison using a novel biomimetic flash-boiling injector}},
  url          = {{http://dx.doi.org/10.1115/ICEF2018-9763}},
  doi          = {{10.1115/ICEF2018-9763}},
  volume       = {{2}},
  year         = {{2018}},
}