Numerical Study on NOx Emission Reduction Mechanism of HCCI Marine Diesel Engine for IMO Tier III Emission Limits

2017 ◽  
Vol Vol 159 (A2) ◽  
Author(s):  
B Li ◽  
H T Gao
Keyword(s):  
Diesel Engine ◽  
Emission Reduction ◽  
Numerical Study ◽  
Combustion Process ◽  
Reduction Rate ◽  
Marine Diesel Engine ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Marine Diesel ◽  
Main Component

With the advantages of ultra-low emissions of oxides of nitrogen (NOX) and high thermal efficiency, the homogeneous charge compression ignition (HCCI) mode applied to marine diesel engine is expected to be one of the technical solutions to meet the International Maritime Organization (IMO) MARPOL73/78 Convention-Annex VI Amendment Tier III requirement. According to the NOX chemical reaction mechanism, taking a marine diesel engine as the application object, the numerical study on the NOX formation characteristics of n-heptane for HCCI combustion process is performed. The results indicate that NO is usually the main component in the generation and emissions of NOX with the n-heptane HCCI mode. The combustor temperature plays more important role in the proportion of NO generation and emission. Compared with the experimental data of conventional marine diesel engine, the emission reduction rate of NOX can achieve an average of more than 95% in using HCCI technology.

NUMERICAL STUDY ON NOX EMISSION REDUCTION MECHANISM OF HCCI MARINE DIESEL ENGINE FOR IMO TIER III EMISSION LIMITS

2021 ◽  
Vol 159 (A2) ◽  
Author(s):  
B Li ◽  
H T Gao
Keyword(s):  
Diesel Engine ◽  
Emission Reduction ◽  
Numerical Study ◽  
Combustion Process ◽  
Reduction Rate ◽  
Marine Diesel Engine ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Marine Diesel ◽  
Main Component

With the advantages of ultra-low emissions of oxides of nitrogen (NOX) and high thermal efficiency, the homogeneous charge compression ignition (HCCI) mode applied to marine diesel engine is expected to be one of the technical solutions to meet the International Maritime Organization (IMO) MARPOL73/78 Convention-Annex VI Amendment Tier III requirement. According to the NOX chemical reaction mechanism, taking a marine diesel engine as the application object, the numerical study on the NOX formation characteristics of n-heptane for HCCI combustion process is performed. The results indicate that NO is usually the main component in the generation and emissions of NOX with the n-heptane HCCI mode. The combustor temperature plays more important role in the proportion of NO generation and emission. Compared with the experimental data of conventional marine diesel engine, the emission reduction rate of NOX can achieve an average of more than 95% in using HCCI technology.

Research on Combustion Process and NOx Formation in a Marine Diesel Engine

2011 ◽  
Vol 214 ◽  
pp. 628-632
Author(s):  
Song Zhou ◽  
Yuan Qing Zhu
Keyword(s):  
Diesel Engine ◽  
Model Simulation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Combustion Model ◽  
Marine Diesel Engine ◽  
Nox Formation ◽  
Transient Combustion ◽  
Marine Diesel ◽  
Simulation Results

This paper presents the simulation results of histories of pressure, temperature and NO concentrations as well as combustion process and NOx formation in a marine diesel engine. The simulation was done within a full engine cycle with a three-dimensional, transient combustion model including a more accurate NO formation model. Simulation results were verified by data obtained from benchmark tests and further analyses of distributions of pollutants were carried out in this paper. Conclusions from simulation about engine combustion and NOx formation have been finally achieved.

scholarly journals An Experimental Investigation into Combustion Fitting in a Direct Injection Marine Diesel Engine

2018 ◽  
Vol 8 (12) ◽  
pp. 2489 ◽  
Author(s):  
Yu Ding ◽  
Congbiao Sui ◽  
Jincheng Li
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Process Model ◽  
Direct Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Marine Diesel Engine ◽  
Test Bed ◽  
Engine Combustion ◽  
Marine Diesel

The marine diesel engine combustion process is discontinuous and unsteady, resulting in complicated simulations and applications. When the diesel engine is used in the system integration simulation and investigation, a suitable combustion model has to be developed due to compatibility to the other components in the system. The Seiliger process model uses finite combustion stages to perform the main engine combustion characteristics and using the cycle time scale instead of the crank angle shortens the simulation time. Obtaining the defined Seiliger parameters used to calculate the engine performance such as peak pressure, temperature and work is significant and fitting process has to be carried out to get the parameters based on experimental investigation. During the combustion fitting, an appropriate mathematics approach is selected for root finding of non-linear multi-variable functions since there is a large amount of used experimental data. A direct injection marine engine test bed is applied for the experimental investigation based on the combustion fitting approach. The results of each cylinder and four-cylinder averaged pressure signals are fitted with the Seiliger process that is shown separately to obtain the Seiliger parameters, and are varied together with these parameters and with engine operating conditions to provide the basis for engine combustion modeling.

Experimental and numerical study on the characteristics of a penetrating exhaust manifold for low-speed two-stroke marine diesel engine

Energy ◽  
2021 ◽  
pp. 121550
Author(s):  
Yingyuan Wang ◽  
Jie Gu ◽  
Mingyang Yang ◽  
Kun Zhang ◽  
Kangyao Deng ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Numerical Study ◽  
Marine Diesel Engine ◽  
Exhaust Manifold ◽  
Low Speed ◽  
Marine Diesel

Nitrogen Oxides Reduction Effect and the Influence Mechanism of Exhaust Valve Lift on a Two-Stroke Marine Diesel Engine

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Lijiang Wei ◽  
Anmin Wu ◽  
Jie Liu ◽  
Mingliang Zhong ◽  
Xuebai Wang
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Exhaust Valve ◽  
Marine Diesel Engine ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Nox Formation ◽  
Influence Mechanism ◽  
Marine Diesel ◽  
Reduction Effect

For the two-stroke marine diesel engine, the action of exhaust valve has a significant impact on scavenging and combustion processes and ultimately affects the engine performances and emissions. In order to reduce nitrogen oxides (NOx) emissions of a two-stroke marine diesel engine, different exhaust valve lifts (EVLs) were achieved by computational fluid dynamics simulation method in this study. The NOx reduction effect and influence mechanism of EVL on a two-stroke marine diesel engine were investigated in detail. The results showed that the in-cylinder residual exhaust gas and the internal exhaust gas recirculation (EGR) rate gradually increased with the decreasing EVL. Although the total mass of charge enclosed in the cylinder did not change much, the composition changed gradually and the maximum internal EGR rate reached 13.17% in this study. The maximum compression pressure and combustion pressure both rose first and then decreased with the decreasing EVL. While the start of combustion and the maximum combustion temperature were basically unaffected by EVL, the indicated power of the engine was also not much impacted when the EVL was changed from increasing 10 mm to decreasing 20 mm. The indicated specific fuel consumption first declined slowly and then rose rapidly as the EVL reduction exceeded 20 mm. NOx emissions decreased monotonously with the decreasing EVL. The reduction of NOx formation rate and the amount of NOx formation mass mainly occurred at the middle and late stages of combustion for the downward moving of residual exhaust gas. NOx emissions were reduced by 12.57% without compromising other engine performances at medium-reduced EVL in this study. However, in order to further reduce NOx emissions at low EVLs, other measures may be needed to make the residual exhaust gas more evenly distributed during the initial stage of combustion.

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