https://orcid.org/0009-0001-0993-2352
![Sample our Built Environment journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5926/TOC-Subject-Sample-2021-Built-Environment.jpg"})
ABSTRACT
The combustion strategy under a higher ammonia energy ratio (AER) is expected to improve the combustion performance of ammonia-diesel dual-fuel (ADDF) engines, leading to additional reductions in greenhouse gas (GHG) emissions. In order to meet the engine’s performance requirements while achieving the low carbon emissions, this study utilized CFD numerical simulations to analyze the combustion and emission characteristics for an ADDF engine at AER levels from 0% to 90%. It focused primarily on evaluating the effectiveness of diesel pilot-injection strategy in reducing GHG emissions at AER50%. The obtained results showed that the unburned NH3 and N2O emissions exhibited an upward trend with the increment of AER, leading to a degradation in the indicated thermal efficiency (ITE), while GHG emissions were more significant than in the original diesel-only combustion mode. Based on AER50%, the ITE exhibited a trend of initially rising and then falling with the increment of diesel pilot-injection ratio (DPR) from 0% to 60%, reaching a maximum value of 47.1% at DPR 40%. At this point, the unburned NH3 emission decreased by 42.4% compared to the DPR0%, and no longer declined after the DPR exceeded 40%. Based on AER 50% and DPR 40%, ITE peaked at 48.1% with the optimal timing for diesel pilot-injection, which represented a 1.6% rise in ITE relative to the original diesel-only combustion mode, while GHG emissions decreased by 35%, and NO emissions increased by 25%.
Abbreviations
| AER | = | Ammonia Energy Ratio |
| IVO | = | Intake Valve Opening |
| CFD | = | Computational Fluid Dynamics |
| LHV | = | Lower Heating Value |
| IC engines | = | Internal Combustion Engines |
| IVC | = | Intake Valve Closing |
| HRR | = | Heat Release Rate |
| ITE | = | Indicated Thermal Efficiency |
| NH3 | = | Ammonia |
| CO | = | Carbon Monoxide |
| SODI-main | = | Start Of Diesel main-Injection |
| NO2 | = | Nitrogen Dioxide |
| SODI-pilot | = | Start Of Diesel pilot-Injection |
| AFRs | = | Air-Fuel Ratios |
| ADDF | = | Ammonia-Diesel Dual-Fuel |
| EVC | = | Exhaust Valve Closing |
| IMEP | = | Indicated Mean Effective Pressure |
| DPR | = | Diesel Pilot-injection Ratio |
| GHG | = | Greenhouse Gas |
| TDC | = | Top Dead Center |
| CO2 | = | Carbon Dioxide |
| EVO | = | Exhaust Valve Opening |
| N2O | = | Nitrous Oxide |
| SODI | = | Start Of Diesel Injection SODI-main |
| HC | = | Hydrocarbon |
| TKE | = | Turbulent Kinetic Energy |
| NO | = | Nitric Oxide |
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
Data used in this research is not publicly available.
Additional information
Notes on contributors
Xu Chen
Xu Chen is currently a graduate student at the School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, China. His main research focus is on the numerical simulation of combustion in carbon-free ammonia fuel internal combustion engines.
Xuelong Miao
Xuelong Miao is a professor at the School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, China. He earned his Doctor of Engineering degree in 2009 from Shanghai Jiao Tong University. His research areas include spray and combustion of carbon-free new energy fuels, vehicle hybrid power, and key components of engine systems.
Yage Di
Yage Di is an associate professor at the School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, China. He received his Doctor of Engineering degree in 2010 from Xi’an Jiao Tong University. His research areas include testing and control of fuel cell systems, automotive functional safety, and internal combustion engine combustion.
Jinbao Zheng
Jinbao Zheng is an associate professor at the School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, China. He received his Doctor of Engineering degree in 2019 from Xi’an Jiao Tong University. His research focuses on the spray technology of carbon-free fuels and the recirculation injection of hydrogen.
Jian Zhou
Jian Zhou is currently a graduate student at the School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, China. His research interests include automotive functional safety and vehicle power saving.