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EN
The process of the atomization and formation of the fuel spray can be described by macro- and microstructure parameters. Knowledge of these parameters may be a key information to conduct further optimization of the combustion process. This paper presents the research results of the microstructure parameters of the diesel oil spray atomized with marine engine injector. A measurement technique, named Laser Induced Fluorescence (LIF) in the combination with Mie scattering was used to determine LIF/Mie ratio across the spray. The fuel was injected into a constant volume vessel. LIF and Mie signals were recorded by two cameras at the same time. Nd:YAG pulsed laser was used to create light sheet for spray illumination. Wavelength of λ = 266 nm was used in this study.
EN
One of the main factors influencing on the optimal combustion process in a marine diesel engine’s cylinder is the fuel injection spray and the fuel atomization. The complexity of mentioned phenomena in the marine diesel engine’s cylinder may cause difficulties in their analysis. Measurement methods, allowing obtaining information about the process of fuel injection and evaporation in the diesel engine’s cylinder are qualified as optical visualization methods. It provides non-invasive measurement of parameters of fuel injection spray. The article presents the analysis of various aspects of optical measurement methods application that allow specifying parameters of fuel injection spray in the diesel engine’s cylinder. Initial studies were carried out using Mie scattering method. In addition, visualization obtained by shadowgraphy method was presented also. The constant volume chamber was used as a working area. The conventional light source was used in case of Mie scattering and a laser light source in shadowgraphy. For the lighting test was used a double-pulse Nd:YAG laser. The wavelength laser 532 nm was used. A course of the injection process was recorded by high-speed camera. The Mie scattering method allows analysing the fuel injection phenomena in macro scale. Specified geometric parameters. The shadowgraphy method allows to asses parameters of diesel fuel injection from marine diesel engine’s injector in the micro scale.
EN
The article presents results of a laboratory study on exhaust gas emission level from a marine diesel engine. The object of the laboratory study was a four-stroke marine diesel engine type Al 25/30 Sulzer, operated at a constant speed. The examination on the engine was carried out according to regulations of the Annex VI to MARPOL 73/78 Convention. The laboratory study consisted of 3 observations: the engine assumed to be operating without malfunctions, delay of the fuel injection by 5° of crankshaft angle in the second engine cylinder, and the leakage of the fuel pump on the second engine cylinder. Additionally, parameters of fuel consumption and thermodynamic parameters of the marine engine were measured during the research. Simulated malfunctions caused changes in total weighed NOx, CO, and CO2 emissions for all considered engine loads. All simulated malfunctions caused a small change in measured thermodynamic parameters of the engine. The engine operation with the delayed fuel injection and the fuel leakage in the fuel pump in one cylinder caused a decrease of NOx and CO emission level. Fuel leakage in the fuel pump causes the CO2 emission to decrease only at low engine load. Calculations of the weighed specific fuel consumption present a 1-2% change in the engine efficiency.
EN
Malfunctions of an intake air duct and an exhaust gas duct have negative impact on the operation of a diesel engine. The article presents results of a laboratory study on nitric oxides (NOx), carbon monoxide (CO) and carbon dioxide (CO2) emission levels from a marine four-stroke diesel engine. CO and CO2 emission levels are connected with oxygen content and specific fuel consumption. For this reason, the results of the laboratory study present oxygen fraction in exhaust gas and specific fuel consumption. The object of the study was laboratory piston engine, operating at constant speed. The measured engine parameters were carried out according to the regulations of the Annex VI to MARPOL 73/78 Convention. The study consisted of tests during engine operation without malfunctions and engine operation with simulated malfunctions. The laboratory study consisted of 3 observations: the engine assumed as operated without malfunctions, throttling of the exhaust gas duct by rotational barrier about 56° and throttling of the air intake duct by reducing of its cross section area by 60%. The simulated malfunctions caused changes in the total weighted NOx and CO emissions in all considered engine loads. All simulated malfunctions resulted in a decrease of all mentioned emission levels in the composition of exhaust gases during the operation at low engine loads and an increase of the CO2 emission level at the maximum engine load operation. The oxygen fraction decrease was observed for throttling of the intake air duct. The calculations of the weighted specific fuel consumption present a 2-3% change in the engine efficiency.
EN
The article presents the results of the laboratory study on nitric oxides (NOx) emission level from marine fourstroke diesel engine. The object of the study was laboratory piston engine, operating at constant speed. Measured engine parameters were necessary to determine the NOx emission in accordance of the requirements of the Annex VI to MARPOL 73/78 Convention. The study consisted of tests during the engine operation without malfunctions and engine operation with simulated malfunctions. Malfunctions of the charge gas exchange in the form of throttling of the air intake duct and the throttling of the exhaust gas duct were taken into account in the simulations. Measurements during the engine operation with simulated malfunctions of the fuel pump on one of the cylinders were also carried out. Mentioned malfunctions were delay of the fuel injection by 5° of the crankshaft angle position and the leakage of the fuel pump of the second engine cylinder. The simulated malfunctions decrease the total weighted NOx emission in all considered the engine loads. All simulated malfunctions resulted in an increase of the NOx emissions during engine operation at low the engine loads and a decrease of the mentioned emission at maximum the engine loads operation. The calculations of the weighted specific fuel consumption present a little change in engine efficiency which are within the range of measuring error of the used method.
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