VANDENS – DUJŲ ŠILUMOS MAINAI GAZ-LIFTO TIPO SKRUBERYJE

In order to reduce sulphur oxide emissions from ships the SOX emission regulations in emission control areas shall be strengthenedand allow only 0,1% of sulphur in marine fuels since 2015. High price of this type of fuel forces ship owners to search for alternativemeans of reducing SOx emissions. Most rational measure is to use scrubber technology. Main type of scrubber that has been widelyanalysed is “shower „ type scrubber. How ever even with widely performed research of these scrubbers they still have somedrawbacks that are of most concern for the owners of small ships. Solution – gaz-lift type scrubbers. In order to improve and adaptgaz-lift type scrubber technology for cleaning of exhaust gases a thorough research has to be performed. Important part of this researchis heat exchange between gas and water in gaz-lift type scrubber. This is done with CFD software – Flow3D. The Simulationresults showed that the temperature of exhaust gases passing the scrubber dropped to around 300-350 k. this results matches theexperimental data, confirms the adequacy of calculation and provides basis for the further use of these models in gaz-lift scrubberresearch.KEY WORDS: GAZ-LIFT, SCRUBBER, SOX, EXHAUST GAS CLEANIN

Research of energy and ecological indicators of a natural gas operated diesel engine

The dissertation deals with the changes of energy and ecological parameters of high-speed compression-ignition internal combustion engine, with conventional fuel injection system, convertible to dual-fuel diesel-natural gas fuelled engine. Considering the specificity of dual-fuel combustion influencing the performance of the combustion process characteris-tic, the method of improving the energy and ecological parameters of the dual-fuel engine by early liquid fuel injection phase was evaluated. Limitations of the improvement of energy and ecological indices for the object of study were investigated and confirmed by numerical mathematical modelling. The heat and exergy balance of the dual-fuel engine was investiga-ted and the efficiency of utilization of secondary heat sources and the total efficiency of en-gine operation were evaluated. Based on complex experimental and mathematical numerical modelling research methodological foundations, which do not require large amount of comp-lex data of engine design and work process parameters, to predict the change of energy values of the convertible engine due dual fuel operation

Mathematical modelling of indicative process parameters of dual-fuel engines with conventional fuel injection system

Modern engine research uses multi-dimensional Mathematical Models (MMs) that are applicable to multi-fuel engines. However, their use involves the availability of detailed technical data on the design and characteristics of the engine, which is not always possible. The use of a one-dimensional MM is more expedient for the prediction of engine parameters, but their application for this purpose has not yet been sufficiently investigated. This publication presents the results of numerical studies evaluating the application of a one-dimensional MM with bi-phase Vibe combustion laws for dual-fuel (DF) Diesel (D) and Natural Gas (NG) engine power parameters. The motor test results of a high-speed 4ČN79.5/95.5 Diesel Engine (DE) with a conventional fuel injection system were used as adequacy criteria. The engines were operated with D100 and DF D20/NG80, in high- (HLM), medium- (MLM), and low- (LLM) load modes, and the angle of Diesel-fuel Injection Timing (DIT) was changed from −1 to −13 °CA in the Before Top Dead Center (BTDC) range. Modelling of the single-phase Vibe combustion law has limited applicability for efficient use only in HLM (with an error of 7%). In the MLM and LLM regimes, owing to non-compliance with real bi-phasic combustion with a strongly extended NG diffusive second phase, the modelling error is 50%. Individual MM matching in MLM and LLM in a DF D20/NG80 experiment detected a burn time increase from between 45 and 50 °CA, to 110 and 200 °CA, respectively. Limited use of the one-dimensional MM in the evaluation of DF engine performance has been identified. When comparing a one-dimensional MM with experimental data, a bi-phase law of heat release characteristic should be considered for better coincidence. In addition, individual MM matching with an experiment on each engine load mode ensured acceptable accuracy in testing and optimising the parameters of the indicator process, including DIT

Comparative research into multicomponent Camelina sativa and rapeseed methyl ester biofuels

The article presents the results of comparative motor research on FAME biofuels using diesel engine VALMET 320 DMG. Energy (ηe, be) and environmental parameters (CO2, CO, NOx, HC, SM) of the engine were estimated. The obtained data on motor research into new biofuels show that the properties of Camelina sativa biofuels are as good as those observed in standardized rapeseed methyl ester biofuels. In case of using Camelina sativa biofuels blends VME and ZME at different engine loads, exhaust emissions from gas smoke could be reduced up to 10% and 30% accordingly comparing with mineral diesel. When the engine is fueled with tested biofuel blends, carbon monoxide emissions decrease by about 5–6%, and the factor for effective performance increases by approximately 4%. In all range of engine loads, an increase in nitrogen oxide emissions reaching 2–3% was observed. In all cases of using biofuel blends, carbon dioxide emissions keep close to the application of mineral diesel

The experimental research of additional energy consumption and exhaust gas emissions from use of marine litter collecting nets

The problem of marine litter is one of the most important ecological problems in many countries. Lack of ecological consciousness and disregard for environmental regulations for marine pollution, results in increasing and sometimes even dangerous amounts of floating litter that either pollutes coastal areas or end up degrading into ever smaller particles and poi-soning marine fauna. To solve this problem one of innovative marine litter collection nets – a light weight, easy to assemble was created. However marine litter collection would create additional trawling work which results in additional air pollutant emissions. It is there for necessary to evaluate the air pollutant emissions that occur during trawling of nets and aim to provide tools for ecological optimization of trawling work so that the least amounts of air pollution would be created while gathering the greatest amount marine litter. The special raft was designed and constructed for such nets test. The test was performed in Curonian lagoon. Marine litter collection requires additional energy consumption, because of increase of thug's engines power to overcome increase of nets resistance, that also leads to additional fuel consumptions and higher exhaust gas emissions. The article is based on experimental research of a light weight marine litter collection nets resistance measurement. Evaluation of additional energy consumption and increased exhaust gas emissions during trawling

Influence of marine fuel properties on ignition, injection delay and energy efficiency

According to the International Council on Combustion Engines (CIMAC) and International Maritime Organization (IMO) statistics, the rational selection of Marine Bunker Fuel (MBF) properties is an effective way to improve operating conditions and energy efficiency of all types of marine Diesel Engines (DEs). The publication presents the results of studies on the influence of heavy and distillate MBF properties on the characteristics of different DE types: high-speed (Caterpillar 3512B, MTU 8V 396TB), medium-speed (SKL VDS 48/42, ChN 26.5/31) ir low-speed (MAN B&W 6S60MC). The aim of work is to form a methodological framework for assessing the influence of marine fuel properties on the energy performance of different types of ship power plants. Numerical methods show that in the case of unfavourable selection of the density and viscosity of marine fuels regulated by the standard ISO 8217:2017, the changes in specific fuel consumption be reach up to 10% low-speed, 4…7% medium-speed, and 2…3% high-speed DEs. As the density varies from light grades to 1010 kg/m3, the change in be is 3…4%. At low viscosity, as the density increases to 1030 kg/m3, the low-speed engine comparative fuel consumption increases by 5%. It is recommended not to use fuel with a density >1010 kg/m3 and a viscosity <300…400 mm2/s. Developed solutions for the rational selection of bunkered marine fuel properties for a specific DE model trough the influence of density and viscosity on fuel injection and combustion characteristics based on multiparametric diagrams of relative fuel consumption change

Research on fuel efficiency and emissions of converted diesel engine with conventional fuel injection system for operation on natural gas

This paper presents a study on the energy efficiency and emissions of a converted high-revolution bore 79.5 mm/stroke 95 mm engine with a conventional fuel injection system for operation with dual fuel feed: diesel (D) and natural gas (NG). The part of NG energy increase in the dual fuel is related to a significant deterioration in energy e ciency ( i), particularly when engine operation is in low load modes and was determined to be below 40% of maximum continuous rating. The e ectiveness of the D injection timing optimisation was established in high engine load modes within the range of a co-combustion ratio of NG 0.4: with an increase in i, compared to D, the emissions of NOx+ HC decreased by 15% to 25%, while those of CO2 decreased by 8% to16%; the six-fold CO emission increase, up to 6 g/kWh, was unregulated. By referencing the indicated process characteristics of the established NG phase elongation in the expansion stroke, the combustion time increase as well as the associated decrease in the cylinder excess air ratio ( ) are possible reasons for the increase in the incomplete combustion product emission