TY - GEN
T1 - Investigation of NO2 formation kinetics in dual-fuel engines with lean premixed methane-air charge
AU - Arabian, Ehsan
AU - Sattelmayer, Thomas
N1 - Publisher Copyright:
Copyright © 2018 ASME.
PY - 2018
Y1 - 2018
N2 - A dual fuel engine concept with lean premixed methane-air charge ignited by a diesel pilot flame is highly promising for reducing NO x and soot emissions. One drawback of this combustion method, however, is the high nitric dioxide (NO 2 ) emissions observed at certain operating points. NO 2 is a toxic gas, which is identifiable by its yellow color. In this paper the conditions leading to increased NO 2 formation have been investigated using a batch reactor model in Cantera. In a first step, it has been found that the high emission levels of NO 2 can be traced back to the mixing of small amounts of quenched CH 4 with NO from the hot combustion zones followed by post-oxidation in the presence of O 2 , requiring that the temperatures are within a certain range. In the second step, NO 2 formation in the exhaust duct of a test engine has been modeled and compared to the experimental results. For that purpose a well-stirred reactor model has been used that calculates the steady-state of a uniform composition for a certain residence time. An appropriate reaction mechanism that considers the effect of NO/NO 2 on methane oxidation at low temperature levels has been used. The numerical results of NO to NO 2 conversion in the duct at low temperature and pressure levels show good agreement with the experimental results for various temperatures and concentrations of unburned methane. The partial oxidation of CH 4 can be predicted well. It can be shown that methane oxidation in the presence of NO/NO 2 at low temperature levels is enhanced via the reaction steps CH 3 + NO 2 ) * CH 3 O + NO and CH 3 O 2 + NO ) * CH 3 O + NO 2 . In addition the elementary reaction HO 2 + NO ) * NO 2 + OH is the important NO oxidizing step.
AB - A dual fuel engine concept with lean premixed methane-air charge ignited by a diesel pilot flame is highly promising for reducing NO x and soot emissions. One drawback of this combustion method, however, is the high nitric dioxide (NO 2 ) emissions observed at certain operating points. NO 2 is a toxic gas, which is identifiable by its yellow color. In this paper the conditions leading to increased NO 2 formation have been investigated using a batch reactor model in Cantera. In a first step, it has been found that the high emission levels of NO 2 can be traced back to the mixing of small amounts of quenched CH 4 with NO from the hot combustion zones followed by post-oxidation in the presence of O 2 , requiring that the temperatures are within a certain range. In the second step, NO 2 formation in the exhaust duct of a test engine has been modeled and compared to the experimental results. For that purpose a well-stirred reactor model has been used that calculates the steady-state of a uniform composition for a certain residence time. An appropriate reaction mechanism that considers the effect of NO/NO 2 on methane oxidation at low temperature levels has been used. The numerical results of NO to NO 2 conversion in the duct at low temperature and pressure levels show good agreement with the experimental results for various temperatures and concentrations of unburned methane. The partial oxidation of CH 4 can be predicted well. It can be shown that methane oxidation in the presence of NO/NO 2 at low temperature levels is enhanced via the reaction steps CH 3 + NO 2 ) * CH 3 O + NO and CH 3 O 2 + NO ) * CH 3 O + NO 2 . In addition the elementary reaction HO 2 + NO ) * NO 2 + OH is the important NO oxidizing step.
UR - http://www.scopus.com/inward/record.url?scp=85060400160&partnerID=8YFLogxK
U2 - 10.1115/ICEF2018-9581
DO - 10.1115/ICEF2018-9581
M3 - Conference contribution
AN - SCOPUS:85060400160
T3 - ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018
BT - Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development
PB - American Society of Mechanical Engineers
T2 - ASME 2018 Internal Combustion Engine Division Fall Technical Conference, ICEF 2018
Y2 - 4 November 2018 through 7 November 2018
ER -