Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Numerical Investigation of Engine Performance and Emission Characteristics of an Ammonia/Hydrogen/n-Heptane Engine Under RCCI Operating Conditions

Xu, Leilei LU and Bai, Xue Song LU (2024) In Flow, Turbulence and Combustion 112(3). p.957-974
Abstract

This paper examines the potential of using ammonia (NH 3) as a primary fuel in heavy-duty engines for decarbonization, with some challenges yet to be addressed. It presents a numerical study of a Reactivity Controlled Compression Ignition engine, where pilot diesel is used to ignite the premixed ammonia/air mixture. The numerical model and combustion mechanism are validated against engine experimental results using methanol and iso-octane fuels and ignition delay times of ammonia/n-heptane mixtures measured in a rapid compression machine. The findings show that the engine can effectively operate with up to 50% of the total energy supplied by premixed ammonia, albeit with slightly elevated NO emissions compared to a... (More)

This paper examines the potential of using ammonia (NH 3) as a primary fuel in heavy-duty engines for decarbonization, with some challenges yet to be addressed. It presents a numerical study of a Reactivity Controlled Compression Ignition engine, where pilot diesel is used to ignite the premixed ammonia/air mixture. The numerical model and combustion mechanism are validated against engine experimental results using methanol and iso-octane fuels and ignition delay times of ammonia/n-heptane mixtures measured in a rapid compression machine. The findings show that the engine can effectively operate with up to 50% of the total energy supplied by premixed ammonia, albeit with slightly elevated NO emissions compared to a diesel-fueled engine. Increasing ammonia further leads to lower combustion efficiency. Hydrogen can be utilized in the ammonia engine to enhance ammonia combustion; however, NO emissions increase further. Ammonia leakage primarily originates from regions near the cold wall, the center of the cylinder, and the crevice. N 2 O mainly forms at the ammonia flame front. Emission of N 2 O is therefore mainly due to flame front quenching near the wall.

(Less)
Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ammonia, Carbon neutrality, Heavy-duty engine, Nitrogen Oxides, Reactivity controlled compression ignition (RCCI)
in
Flow, Turbulence and Combustion
volume
112
issue
3
pages
18 pages
publisher
Springer
external identifiers
  • scopus:85164023690
ISSN
1386-6184
DOI
10.1007/s10494-023-00453-y
language
English
LU publication?
yes
id
92b37566-f35e-486a-a641-9f5a59dd17d3
date added to LUP
2023-11-07 14:40:32
date last changed
2024-07-17 12:14:16
@article{92b37566-f35e-486a-a641-9f5a59dd17d3,
  abstract     = {{<p>This paper examines the potential of using ammonia (NH <sub>3</sub>) as a primary fuel in heavy-duty engines for decarbonization, with some challenges yet to be addressed. It presents a numerical study of a Reactivity Controlled Compression Ignition engine, where pilot diesel is used to ignite the premixed ammonia/air mixture. The numerical model and combustion mechanism are validated against engine experimental results using methanol and iso-octane fuels and ignition delay times of ammonia/n-heptane mixtures measured in a rapid compression machine. The findings show that the engine can effectively operate with up to 50% of the total energy supplied by premixed ammonia, albeit with slightly elevated NO emissions compared to a diesel-fueled engine. Increasing ammonia further leads to lower combustion efficiency. Hydrogen can be utilized in the ammonia engine to enhance ammonia combustion; however, NO emissions increase further. Ammonia leakage primarily originates from regions near the cold wall, the center of the cylinder, and the crevice. N <sub>2</sub> O mainly forms at the ammonia flame front. Emission of N <sub>2</sub> O is therefore mainly due to flame front quenching near the wall.</p>}},
  author       = {{Xu, Leilei and Bai, Xue Song}},
  issn         = {{1386-6184}},
  keywords     = {{Ammonia; Carbon neutrality; Heavy-duty engine; Nitrogen Oxides; Reactivity controlled compression ignition (RCCI)}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{957--974}},
  publisher    = {{Springer}},
  series       = {{Flow, Turbulence and Combustion}},
  title        = {{Numerical Investigation of Engine Performance and Emission Characteristics of an Ammonia/Hydrogen/n-Heptane Engine Under RCCI Operating Conditions}},
  url          = {{http://dx.doi.org/10.1007/s10494-023-00453-y}},
  doi          = {{10.1007/s10494-023-00453-y}},
  volume       = {{112}},
  year         = {{2024}},
}