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The Potential of SNCR Based NOx Reduction in a Double Compression Expansion Engine

Muric, Kenan LU ; Tunestal, Per LU ; Andersson, Arne ; Andersson, Lennart and Oom, Kerstin (2018) In SAE Technical Papers 2018-April.
Abstract

Selective Non-Catalytic Reduction (SNCR), used to reduce the emissions of nitrogen oxides (NOx), has been a well-established technology in the power plant industry for several decades. The SNCR technique is an aftertreatment strategy based on thermal reduction of NOx at high temperatures. In the compression ignition engine application, the technology has not been applicable due to low exhaust temperatures, which makes the SCR (Selective Catalytic Reduction) system essential for efficient nitrogen oxide reduction to fulfill the environment legislation. For a general Double Compression Expansion Engine (DCEE) the complete expansion cycle is split in two separate cycles, i.e. the engine is a split cycle engine. In the... (More)

Selective Non-Catalytic Reduction (SNCR), used to reduce the emissions of nitrogen oxides (NOx), has been a well-established technology in the power plant industry for several decades. The SNCR technique is an aftertreatment strategy based on thermal reduction of NOx at high temperatures. In the compression ignition engine application, the technology has not been applicable due to low exhaust temperatures, which makes the SCR (Selective Catalytic Reduction) system essential for efficient nitrogen oxide reduction to fulfill the environment legislation. For a general Double Compression Expansion Engine (DCEE) the complete expansion cycle is split in two separate cycles, i.e. the engine is a split cycle engine. In the first cylinder the combustion occurs and in the second stage the combustion gas is introduced and further expanded in a low-pressure expansion cylinder. The combustion cylinder is connected with the expansion cylinder through a large insulated high-pressure tank. If an ammonia based solution is injected after the combustion cylinder, the residence time and high gas temperature in the high-pressure tank allows the Selective Non-Catalytic Reduction mechanisms to ensue. In this paper, AUS 32 vaporization efficiency was studied by injection droplet distribution measurements and CFD simulations. The Selective Non-Catalytic Reduction concept was evaluated utilizing a 1D GT-SUITE model of a potential DCEE concept where the SNCR based mechanisms were added. Engine speed, normalized stoichiometric ratio (NSR), load and air-fuel excess ratio were swept in the 1D simulation process. The simulation results suggest efficient vaporization of AUS 32 and the presence of SNCR mechanisms in the Double Compression Expansion Engine's medium and high load operating points was verified with conversion efficiency above 50 % in some of the simulation cases for NSR = 1 and close to 80-100 % for NSR = 2 and NSR = 3 when the exhaust gas temperature from the combustion cylinder was in the optimal range for SNCR based reactions.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
SAE Technical Papers
volume
2018-April
publisher
Society of Automotive Engineers
external identifiers
  • scopus:85045531615
ISSN
0148-7191
DOI
10.4271/2018-01-1128
project
Motorkoncept 2
language
English
LU publication?
yes
id
c1115fa6-ff27-4b23-905a-233dc6981617
date added to LUP
2018-04-27 14:56:54
date last changed
2022-04-25 07:09:21
@article{c1115fa6-ff27-4b23-905a-233dc6981617,
  abstract     = {{<p>Selective Non-Catalytic Reduction (SNCR), used to reduce the emissions of nitrogen oxides (NO<sub>x</sub>), has been a well-established technology in the power plant industry for several decades. The SNCR technique is an aftertreatment strategy based on thermal reduction of NO<sub>x</sub> at high temperatures. In the compression ignition engine application, the technology has not been applicable due to low exhaust temperatures, which makes the SCR (Selective Catalytic Reduction) system essential for efficient nitrogen oxide reduction to fulfill the environment legislation. For a general Double Compression Expansion Engine (DCEE) the complete expansion cycle is split in two separate cycles, i.e. the engine is a split cycle engine. In the first cylinder the combustion occurs and in the second stage the combustion gas is introduced and further expanded in a low-pressure expansion cylinder. The combustion cylinder is connected with the expansion cylinder through a large insulated high-pressure tank. If an ammonia based solution is injected after the combustion cylinder, the residence time and high gas temperature in the high-pressure tank allows the Selective Non-Catalytic Reduction mechanisms to ensue. In this paper, AUS 32 vaporization efficiency was studied by injection droplet distribution measurements and CFD simulations. The Selective Non-Catalytic Reduction concept was evaluated utilizing a 1D GT-SUITE model of a potential DCEE concept where the SNCR based mechanisms were added. Engine speed, normalized stoichiometric ratio (NSR), load and air-fuel excess ratio were swept in the 1D simulation process. The simulation results suggest efficient vaporization of AUS 32 and the presence of SNCR mechanisms in the Double Compression Expansion Engine's medium and high load operating points was verified with conversion efficiency above 50 % in some of the simulation cases for NSR = 1 and close to 80-100 % for NSR = 2 and NSR = 3 when the exhaust gas temperature from the combustion cylinder was in the optimal range for SNCR based reactions.</p>}},
  author       = {{Muric, Kenan and Tunestal, Per and Andersson, Arne and Andersson, Lennart and Oom, Kerstin}},
  issn         = {{0148-7191}},
  language     = {{eng}},
  month        = {{01}},
  publisher    = {{Society of Automotive Engineers}},
  series       = {{SAE Technical Papers}},
  title        = {{The Potential of SNCR Based NO<sub>x</sub> Reduction in a Double Compression Expansion Engine}},
  url          = {{http://dx.doi.org/10.4271/2018-01-1128}},
  doi          = {{10.4271/2018-01-1128}},
  volume       = {{2018-April}},
  year         = {{2018}},
}