ANN based evaluation of the NOx concentration in the exhaust gas of a marine two-stroke diesel engine

The paper presents a 3D model of the processes taking place in the cylinder of a large 4-stroke marine engine. The model is based on CFD calculations performed on the moving mesh. The modelling range includes the full duty cycle (720° crankshaft position) and the complete geometry of the cylinder with inlet and exhaust ducts. The input data, boundary conditions and validation data were obtained by direct measurements on the real object. Fuel injection characteristics were obtained by Mie scattering measurements in a fixed-volume chamber. The modelling results have been validated in terms of the pressure characteristics of the engine’s cylinder within the entire range of its loads. The mean error did not exceed 1.42% for the maximum combustion pressure and 1.13% for the MIP (Mean Indicated Pressure). The model was also positively validated in terms of the O2 and NOx content of the exhaust gas. The mean error in this case was 1.2% for NOx fractions in the exhaust gas and 0.4% for O2 fractions. The complete model data has been made available in the research data repository on an open access basis.

Section: Fig 2 Diagram Of the Moving Meshmentioning

confidence: 99%

“…This mesh allowed the full engine cycle to be calculated using 25,110 iterations. The mesh and the complete configuration files are provided in the open access data [20] and the calculation performance analysis using this grid in [22].…”

Section: Fig 2 Diagram Of the Moving Meshmentioning

confidence: 99%

High Quality Multi-Zone and 3D CFD Model of Combustion in Marine Diesel Engine Cylinder

Cuper-Przybylska

Nguyen

Cao

et al. 2023

“…For this reason, refineries are undertaking intensive technological works aimed at reducing the production costs of this type of fuel while maintaining their high functional quality [2,22]. Such works also require research examinations, especially numerical simulations, as well as engine tests to assess the combustion, emission, and structural effects of these fuels' application [11,14,16,17,18,20,23]. It turns out that there are few countries in the world that are conducting this type of research on real objects, i.e., full-size marine engines, mainly due to their complex nature [12,24].…”

Section: Introductionmentioning

confidence: 99%

Energy and Emission Quality Ranking of Newly Produced Low-Sulphur Marine Fuels

Korczewski

2022

The article describes the methodology of engine tests on new types of low-sulphur marine fuels in laboratory conditions in order to conduct a comprehensive assessment of their suitability for powering full-size marine engines. The innovativeness of the proposed solution consists of adapting the laboratory Diesel Engine Test Bed to carry out experimental tests using residual and alternative fuels so that it is possible to imitate the real operating conditions of the ship engine. The main aim of the research program was to assess the energy efficiency of six different low-sulphur marine fuels and their impact on the chemical emissivity of engine exhaust gases and air pollution with toxic and harmful chemical compounds. In order to achieve the research purpose formulated in this way, it was necessary to: (1) equip the constructed laboratory stand with highly specialised measuring equipment and (2) develop a technology for determining diagnostic parameters representing the basis for developing a ranking of the energy and emission quality of the tested marine fuels according to the proposed physical model. The model distinguishes 10 diagnostic parameters that, after normalisation, form two subsets of evaluation parameters - stimulant and destimulant. Determining their values made it possible to estimate a synthetic variable, according to which all the tested fuels were adjusted in the order from the “best” to the “worst”, in accordance with the adopted qualitative criteria of such an assessment. The results of the laboratory tests show that among the considered fuels, i.e., MDO, MGO, RMD 80/L, RMD 80/S, RME 180, and RMG 380 type, the best solution is to use MDO distillate fuel to power full-size marine engines. However, taking into account its high purchase price, a rational alternative decision is to choose RMG 380 type residual fuel, which ranks second in the ranking of the functional quality of the tested marine fuels.

“…in both compression-ignition and spark ignition engines [8]. Regarding compressionignition engines, one can refer to the work of Kowalski [9], who characterised NO x and fuel consumption from 15 and 16 inputs, respectively. Celik and Arcaklioglu [10] predicted the consumption, fuel-air equivalence ratio, and EGT, using as inputs the engine power, engine speed, and water temperature.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Pre-Injection System of a Marine Diesel Engine Through Multiple-Criteria Decision-Making and Artificial Neural Networks

Rodríguez

Galdo

Rodrı́guez

et al. 2021

The present work proposes several pre-injection patterns to reduce nitrogen oxides in the Wärtsilä 6L 46 marine engine. A numerical model was carried out to characterise the emissions and consumption of the engine. Several pre-injection quantities, durations, and starting instants were analysed. It was found that oxides of nitrogen can be noticeably reduced but at the expense of increasing consumption as well as other emissions such as carbon monoxide and hydrocarbons. According to this, a multiple-criteria decision-making (MCDM) model was established to select the most appropriate parameters. Besides, an artificial neural network (ANN) was developed to complement the results and analyse a huge quantity of alternatives. This hybrid MCDM-ANN methodology proposed in the present work constitutes a useful tool to design new marine engines.