This scientific study is focused on the analysis of an influence of the experimental diesel fuel mixtures containing various portions of the biocomponent on the unregulated gaseous emissions generated by a diesel motor vehicle, which is equipped with the diesel engine utilizing the direct fuel injection system “common rail”. The main reason for the choice of this engine type was its wide usage in the current vehicles. The experimental diesel fuel mixtures were created as a mixture of the standard low-sulfur diesel fuel with the biodiesel, using various mixing ratios. The experiments were realized by means of a special 13-regime engine test cycle, which was intentionally developed for the diesel combustion engines. All the individual experiments were performed on the base of the given test cycle with 13 different operational modes. The obtained results offer a complex view on the generation of the unregulated emissions with regard to the operational conditions and taking into consideration operational loading of the given experimental engine.

Large transoceanic ships use marine ancillary diesel engines for generating electricity, which, on the other hand, produce a remarkable amount of harmful emissions during the combustion process. The International Maritime Organisation (IMO) establishes standards that limit the amount of harmful emissions produced during the engine combustion cycle in maritime transport. Because of this restriction, new alternative fuels entered the market. Experiments had been performed with various testing fuels created from biodiesel and ULSD-F (Ultra Low Sulphur Diesel-Fuel) in the ratios of 0%, 50%, 80%, and 100%. During the tests, the engine ran at different speeds and loads so that the mixed fuel influence on engine operation could be observed in detail and investigated.

The scientific contribution is focused on the analysis and optimization of combustion conditions concerning the dual-fuel mixtures. The greatest attention was paid to the temperature of intake air when a mixture of ethanol and gasoline created the applied fuel. An experimental fuel mixture was added into the intake pipe and ultra-low sulphur diesel fuel (ULSDF) was added directly into the engine cylinder using the CR (common rail) injection system. The article analysed the medium- and high-level operational engine load, whereby the engine timing parameters originally corresponded to a conventional diesel engine. The obtained results of the performed analysis showed that the temperature of intake air affected the following operational parameters: delay of ignition, pressure rise rate in the engine cylinder and the maximum level of pressure in the engine cylinder. Lower values of the intake air temperature enabled higher injection speeds for the ethanol–sustainable mixture (ESM), especially at high engine loads. An increase in the injection speed was possible due to lower charge air temperature. While there were reduced nitrogen oxide emissions, we also noted a reduction in both carbon monoxide emissions and the total amount of unburned hydrocarbon emissions.

The innovative system, which was developed for analysis and correction of motor management, is determined for the solution of practical problems concerning the operation of the piston combustion engines. Programming of the ignition curves and fuel maps without relevant feedback, namely, without information obtained from the engine operation, increases the risk of detonation combustion, which can destroy the combustion engine. However, the main application area of this system is the development of an algorithm, which is specified for control of the combustion process based on the HCCI technology (Homogenous Charge Compression Ignition). Nowadays, the functional principle of the HCCI engine is one of the most effective possibilities on how to reach higher operational efficiency of the gasoline engine, that is, closer to the efficiency level of the diesel driving units.

The vehicle emissions tests, which are performed using the Portable Emissions Measurement Systems (PEMS), indicate that the diesel cars produce several times more NOx emissions on the road than during certification realised according to the me...