COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF NOx REDUCTION BY AMMONIA INJECTION IN THE MAN B&W 7S50MC MARINE ENGINE

2021 ◽  
Vol 156 (A3) ◽  
Author(s):  
M I Lamas ◽  
C G Rodríguez ◽  
J D Rodríguez ◽  
J Telmo
Keyword(s):  
Numerical Model ◽  
Direct Injection ◽  
Nox Reduction ◽  
Water Injection ◽  
Injection Timing ◽  
Restrictive Temperature ◽  
Marine Engine ◽  
Computational Fluid Dynamics Analysis ◽  
Restrictive Legislation ◽  
Ammonia Injection

Taking into account the importance of NOx (nitrogen oxides) emissions from marine engines and the current increasingly restrictive legislation, this work aims to develop a numerical model to study NOx reduction. To this end, direct injection of NH3 (ammonia) into the combustion chamber was proposed in the MAN B&W 7S50MC marine engine. The numerical model was employed to analyze several injection temperatures, injection timings and ammonia to fuel ratios, obtaining NOx reductions of almost 60%. Besides, a comparison between ammonia injection and water injection was done. The results showed that ammonia is more efficient than water to reduce NOx with a negligible influence on other pollutants such as CO (carbon monoxide) and HC (hydrocarbons). Nevertheless, ammonia is efficient in a very restrictive temperature and injection timing range. This numerical model was compared with experimental measurements, obtaining satisfactory results which validate the work.

Computational Fluid Dynamics Analysis of NOx Reduction by Ammonia Injection in the Man B&W 7s50mc Marine Engine

2014 ◽  
Vol 156 (A3) ◽  
Keyword(s):  
Numerical Model ◽  
Direct Injection ◽  
Nox Reduction ◽  
Water Injection ◽  
Injection Timing ◽  
Restrictive Temperature ◽  
Marine Engine ◽  
Computational Fluid Dynamics Analysis ◽  
Restrictive Legislation ◽  
Ammonia Injection

Taking into account the importance of NOx (nitrogen oxides) emissions from marine engines and the current increasingly restrictive legislation, this work aims to develop a numerical model to study NOx reduction. To this end, direct injection of NH3 (ammonia) into the combustion chamber was proposed in the MAN B&W 7S50MC marine engine. The numerical model was employed to analyse several injection temperatures, injection timings and ammonia to fuel ratios, obtaining NOx reductions of almost 60%. Besides, a comparison between ammonia injection and water injection was done. The results showed that ammonia is more efficient than water to reduce NOx with a negligible influence on other pollutants such as CO (carbon monoxide) and HC (hydrocarbons). Nevertheless, ammonia is efficient in a very restrictive temperature and injection timing range. This numerical model was compared with experimental measurements, obtaining satisfactory results which validate the work.

scholarly journals Numerical Analysis of NOx Reduction Using Ammonia Injection and Comparison with Water Injection

2020 ◽  
Vol 8 (2) ◽  
pp. 109 ◽  
Author(s):  
María Isabel Lamas Galdo ◽  
Laura Castro-Santos ◽  
Carlos G. Rodriguez Vidal
Keyword(s):  
Diesel Engine ◽  
Nox Reduction ◽  
Water Injection ◽  
The Other ◽  
Chemical Effect ◽  
Injection Timing ◽  
Marine Diesel Engine ◽  
Marine Diesel ◽  
Dilution Effects ◽  
Ammonia Injection

This work analyzes NOx reduction in a marine diesel engine using ammonia injection directly into the cylinder and compares this procedure with water injection. A numerical model based on the so-called inert species method was applied. It was verified that ammonia injection can provide almost 80% NOx reduction for the conditions analyzed. Furthermore, it was found that the effectiveness of the chemical effect using ammonia is extremely dependent on the injection timing. The optimum NOx reduction was obtained when ammonia is injected during the expansion stroke, while the optimum injection timing using water is near top dead center. Chemical, thermal, and dilution effects of both ammonia and water injection were compared. The chemical effect was dominant in the case of ammonia injection. On the other hand, water injection reduces NOx through dilution and, more significantly, through a thermal effect.

Application of an Experimental EGR System to a Medium Speed EMD Marine Engine

2009 ◽  
Author(s):  
John Hedrick ◽  
Steven G. Fritz ◽  
Ted Stewart
Keyword(s):  
Nox Reduction ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Marine Engine ◽  
Air Temperatures ◽  
Medium Speed ◽  
Particulate Matter Emissions ◽  
Baseline Test ◽  
Exhaust Energy ◽  
Gas Recirculation

This paper focuses on quantifying emission reductions associated with various on-engine technologies applied to Electro-Motive Diesel two-cycle diesel engines, which are very popular in marine and locomotive applications in North America. This paper investigates the benefits of using exhaust gas recirculation (EGR), separate circuit aftercooler, and retarded injection timing on a EMD 12-645E7 marine engine. The EGR system alone provided up to a 32.9% reduction in brake specific Nitrogen Oxides (NOx) emissions while demonstrating less than one percent increase in cycle brake specific fuel consumption (BSFC). The brake specific particulate matter emissions increased somewhat, but at a modest rate based on the amount of NOx emission reduction. When the enhanced aftercooler system was combined with the addition of EGR, there was a 31.9% reduction in NOx and essentially no change to the BSFC when compared to the baseline test. The minimum manifold air temperature (MAT) was limited due to the size of the standard EMD aftercooler heat exchanger that is fitted on the engine. No efforts to modify the turbocharger to improve the turbo match to take advantage of the lower manifold air temperatures and the corresponding lower exhaust energy. Once 4° static injection timing retard was introduced, along with the EGR and the minimum MAT, a maximum NOx reduction of 49% was realized with only a 1.1% increase over the baseline BSFC.

A Numerical Study of NOx Reduction for a DI Diesel Engine With Complex Geometry

2004 ◽  
Vol 126 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Renshan Liu ◽  
Chao Zhang
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Fuel Injection ◽  
Complex Geometry ◽  
Numerical Study ◽  
Direct Injection ◽  
Nox Reduction ◽  
Geometrical Parameters ◽  
Injection Timing ◽  
Di Diesel Engine

A numerical study of NOx reduction for a Direct Injection (DI) Diesel engine with complex geometry, which includes intake/exhaust ports and moving valves, was carried out using the commercial computational fluid dynamics software KIVA-3v. The numerical simulations were conducted to investigate the effects of engine operating and geometrical parameters, including fuel injection timing, fuel injection duration, and piston bowl depth, on the NOx formation and the thermal efficiency of the DI Diesel engine. The tradeoff relationships between the reduction in NOx and the decrease in thermal efficiency were established.

scholarly journals 2D CFD Simulation of Water Injection Strategies in a Large Marine Engine

2019 ◽  
Vol 7 (9) ◽  
pp. 296 ◽  
Author(s):  
Senčić ◽  
Mrzljak ◽  
Blecich ◽  
Bonefačić
Keyword(s):  
Cfd Simulation ◽  
Soot Formation ◽  
Direct Injection ◽  
Water Injection ◽  
Engine Performance ◽  
Nox Emissions ◽  
Water Emulsion ◽  
Marine Engine ◽  
Soot Emissions ◽  
Injection Strategies

A two-dimensional computational fluid dynamics (2D CFD) simulation of a low-speed two-stroke marine engine simulation was performed in order to investigate the performance of 2D meshes that allow the use of more complex chemical schemes and pollutant formation analysis. Various mesh density simulations were compared with a 3D mesh simulation and with the experimentally obtained cylinder pressure. A heavy fuel model and a soot model were implemented in the software. Finally, the influences of three water injection strategies were simulated and evaluated in order to investigate the capability of the model and the influence of water injection on NOx formation, soot formation, and engine performance. We conclude that the direct water injection strategy reduces NOx emissions without adversely affecting the engine performance or soot emissions. The other two strategies—Intake air humidification and direct injection of fuel–water emulsion—reduced NOx emissions but at the cost of higher soot emissions or reduced engine performance.

scholarly journals Effects of pilot injection timing and EGR on a modern V6 common rail direct injection diesel engine

2013 ◽  
Vol 50 ◽  
pp. 012008 ◽  
Author(s):  
Nik Rosli Abdullah ◽  
Rizalman Mamat ◽  
Miroslaw L Wyszynski ◽  
Anthanasios Tsolakis ◽  
Hongming Xu
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Common Rail ◽  
Injection Timing ◽  
Pilot Injection ◽  
Direct Injection Diesel Engine

scholarly journals A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Simulation Software ◽  
Dual Fuel ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Cylinder Pressure ◽  
Marine Engine ◽  
Full Load ◽  
Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

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