Experimental Assessment of Ozone Addition Potential in Direct Injection Compression Ignition Engines

2019 ◽  
Author(s):  
Michele Bardi ◽  
Guillaume Pilla ◽  
Mickaël Matrat
Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1830 ◽  
Author(s):  
Moonchan Kim ◽  
Jungmo Oh ◽  
Changhee Lee

Compression ignition engines used as marine engines are the most efficient internal combustion engines. They are well-established products, and millions are already on the market. Water-in-MDO (marine diesel oil) emulsions are the best alternative fuel for compression ignition engines and can be utilised with the existing setup of 2.0 L automotive common rail direct injection (CRDI) engines. They have benefits for the simultaneous reduction of both NOx and smoke (black carbon). Furthermore, they have a significant impact on the improvement of combustion efficiency. Micro-explosions are the most important phenomenon of water-in-diesel emulsions inside an internal combustion engine chamber. They affect both the emission reduction and combustion efficiency improvements directly and indirectly in accordance with the brake mean effective pressure (BMEP) and rpm. Owing to the influence of micro-emulsions on the combustion and emissions of water-in-diesel emulsion fuel, the reduction ratios of NOx and smoke in a used engine are approximately 30% and 80%, respectively. The effect of the operating parameters on micro-emulsions is presented.


2020 ◽  
pp. 146808742095132
Author(s):  
José V Pastor ◽  
Antonio García ◽  
Carlos Micó ◽  
Felipe Lewiski

Considering the need of pollutant emissions reduction and the high cost of the after-treatment systems, in-cylinder solutions for pollutant reduction are becoming more and more relevant. Among different proposals, new piston geometries are considered an attractive solution for reducing both soot and nitrogen oxides emissions in compression ignition engines. For this reason, this paper evaluates the soot formation and combustion characteristics of a novel piston geometry proposal, called stepped lip-wave, for light-duty engines. It is compared with other two well-known bowl geometries: re-entrant and stepped lip. The study was performed in an optical single-cylinder direct injection compression ignition engine. Two optical techniques (2 color pyrometry and OH* chemiluminescence) were applied for analyzing soot formation in each piston geometry. Test were performed at different engine loads, fuel injection characteristics and exhaust gas recirculation configuration. The re-entrant piston presents higher soot formation and a slower late oxidation process in comparison with the other two geometries. Stepped lip and stepped lip-wave present similar soot formation levels. However, stepped lip-wave showed a more efficient and faster soot oxidation process during the final combustion stages. Results confirm the potential of the stepped lip-wave concept to reduce soot emissions and achieve a cleaner energy production system.


2020 ◽  
Vol 20 (4) ◽  
pp. 345-361
Author(s):  
Haydar M. Razoqe ◽  
Mahmoud A. Mashkour

The present research investigated multi-zone single-cylinder four-stroke direct-injection model. The model simulates closed cycle processes and describes the combustion behavior by employing thermodynamic equations of a penetration spray theories. The model has been coded on the base of the programming tools of Matlab software. In this simulation model, the combustion events is divided into five zones, in order to determine the amount of fuel, access air, and amount of products in each zone. The simulation model, produced in this work, provides a more accurate framework for zero dimensional model by introducing physical zones within the model that correspond to the combustion structures in the engine. Comparison the results of the simulation model with other methods in the published researches shows that the behavior of engine parameters with theoretical and experimental earlier works has a good agreement. From the simulation model results can be concluded that, there is a change in the limits of the combustion zones with changing engine speed, amount of injected fuel, intake air pressure, and temperature, especially in the rich premixed burn zone.    


2020 ◽  
pp. 146808742092104
Author(s):  
Priya Priyadarshini ◽  
Aimilios Sofianopoulos ◽  
Sotirios Mamalis ◽  
Benjamin Lawler ◽  
Dario Lopez-Pintor ◽  
...  

The development of gasoline compression ignition engines operating in a low temperature combustion mode depends heavily on robust control of the heat release profile. Partial fuel stratification is an effective method for controlling the heat release by creating a stratified mixture prior to autoignition, which can be beneficial for operation across a wide load range. In this study, three-dimensional large eddy simulations were used to model a double direct injection strategy for which 80% of the fuel was injected during the intake stroke, and 20% of the fuel was injected at varying timing during the compression stroke. The simulations replicated a set of experiments performed at Sandia National Laboratories on a 1-L single-cylinder research engine using E10 gasoline (gasoline fuel containing 10% vol. ethanol). The objective of this study is to analyze the effects of the double direct injection strategy on the compositional and thermal stratification of the mixture, and understand the best use of this operating strategy. The modeling results indicated that by retarding the start of the second injection, the mixture stratification increases, which can be used to control the autoignition timing and the combustion phasing. Ignition and CA50 (crank angle of 50% mass fraction burned) are dictated by the mass concentration of the richest zones in the combustion chamber, as well as their location. The richer zones have the lowest temperatures before ignition primarily due to evaporative cooling from direct fuel injection. Overall, this study enhances the understanding of partial fuel stratification that can be used for controlling the heat release in gasoline compression ignition engines.


Sign in / Sign up

Export Citation Format

Share Document