The paper attempts to determine the impact of fuel impurities on the spark discharge energy and the wear of the spark plug electrode. Spark plugs were analyzed in two typical configurations of the ignition system. A number of tests were conducted to determine the wear of the spark plug electrode exposed to different types of impurities. The spark discharge energy for new and worn spark plugs was determined through calculation.

The paper analyses the possibilities of treating the ignition cable in the internal combustion engine as a distributed parameter system. It presents the experimental verification of computer simulations of signal propagation generated by ignition systems in the ignition cables, modelled by the distributed parameter system. The tests conducted to determine the wave parameters of ignition cables, as well as the results of numerical simulations and their experimental verifications, are presented. It is concluded that the modelling of the ignition cable by means of a long line gives positive results that can be used for the design of a spark plug with impedance equal to wave impedance of the ignition cable.

In former coal-mining areas, unseen underground fires can pose a significant danger to people’s health. Careful observation of changes in plant cover can offer an important early warning of such threats.

The paper presents a method of choosing parameters of a mathematical model for simulation of a working cycle of compression-ignition engine on the basis of experimental measurements. In order to choose the parameters of the model, the Nelder-Mead method has been used. As a result of such an approach, a simplified mathematical model with very good numerical effectiveness can be used for simulation of the working cycle of the engine, while very good compatibility of numerical results and experimental measurements is ensured. Suitable algorithms and results of calculations are presented.

The article presents the analysis of the correlation between the self-ignition parameters and the ultimate and proximate analysis, as well as the petrographic properties of Polish lignite, sub-bituminous coal, bituminous coal and anthracite. The following coal properties were determined: the moisture, ash content, volatile matter and sulfur content, gross calorific value, net calorific value, C, O, N and H contents, total porosity, ash oxide composition, rates of spontaneous combustion in 237°C and 190°C, and activation energy. During the petrographic analysis, maceral composition and random reflectance were determined. To determine the linear correlation between the self-ignition parameters and the analyzed coal properties, the Pearson correlation coefficient was calculated. The results show that there is no strong linear correlation between the lignite tendency to self-ignition and its petrographic properties. However, a strong negative correlation between the rate of spontaneous combustion and moisture and volatile matter content was observed. In the case of bituminous coal, strong correlations between self-combustion parameters and various coal properties were confirmed. The most noteworthy are the correlations between self-ignition parameters and the maceral composition, that is, between the content of macerals of the inertinite group in coal and content of macerals of the huminite/vitrinite group. The obtained results suggest that the spontaneous combustion tendency of coal increases with the increasing content of semifusinite and liptinite.

The engine simulations have become an integral part of engine design and development. They are based on approximations and assumptions. The precision of the results depends on the accuracy of these hypotheses. The simplified models of frozen composition, chemical equilibrium and chemical kinetics provide the compositions of combustion products for engine cycle simulations. This paper evaluates the effects of different operating conditions and hypotheses on the exergetic analysis of a spark-ignition engine. The Brazilian automotive market has the highest number of flex-fuel vehicles. Therefore, a flex-fuel engine is considered for simulations in order to demonstrate the effects of these different hypotheses. The stroke length and bore diameter have the same value of 80 mm. The in-cylinder irreversibility is calculated for each case at the closed part of the engine cycle. A comparative analysis of these hypotheses provides a comprehensive evaluation of their effects on exergetic analysis. Higher values of accumulated irreversibility are observed for the oversimplified hypothesis.

The paper discusses the modelling of magnetic coupling in ignition coils by fractional differential equations. The use of fractional-order coupling allows us to consider the losses caused by the non-linearity of the ferromagnetic core of the ignition coil and obtain the waveform of the ignition coil’s secondary voltage closest to the values obtained experimentally.

The aim of the study was to determine the influence of the amount of a commonly used binder in foundry work, furfuryl resin – on the course of the thermal regeneration of used moulding sand. The thermal regeneration procedure was carried out at a temperature of 525°C, the required temperature determined according to a specific procedure, and a lower and less effective temperature of 400°C. On the basis of the ignition losses, the influence of the regeneration temperature on the effects of the procedures carried out was compared. It was found that 400°C was too low to effectively clean the binder matrix, but that the more resin in the spent sand, the more intense the cleaning effect. When the required regeneration temperature for furfuryl resin of 523°C was used, higher binder degradation kinetics were observed due to the additional energy supplied to the process from the combustion of a large amount of organic material in the moulding sand.

To investigate the effect of different proximate index on minimum ignition temperature(MIT) of coal dust cloud, 30 types of coal specimens with different characteristics were chosen. A two-furnace automatic coal proximate analyzer was employed to determine the indexes for moisture content, ash content, volatile matter, fixed carbon and MIT of different types of coal specimens. As the calculated results showed that these indexes exhibited high correlation, a principal component analysis (PCA) was adopted to extract principal components for multiple factors affecting MIT of coal dust, and then, the effect of the indexes for each type of coal on MIT of coal dust was analyzed. Based on experimental data, support vector machine (SVM) regression model was constructed to predicate the MIT of coal dust, having a predicating error below 10%. This method can be applied in the predication of the MIT for coal dust, which is beneficial to the assessment of the risk induced by coal dust explosion (CDE).

Power generation units, suitable for individual users and small scale applications, are mainly based on spark ignition engines. In recently performed research, reductions of emissions coming from such units, especially considering carbon dioxide emissions, are deemed as the issue of particular importance. One of solutions, postponed to reduce impact of spark ignition engine-based units on the natural environment, is transition from fossil fuels into renewable gaseous fuels, as products of organic digestion. Nonetheless, development of new solutions is required to prevent further carbon dioxide emissions. The paper presents a novel dual approach developed to reduce carbon dioxide emissions from stationary power units, basing on spark ignition engine. The discussed approach includes both reduction in carbon content in the fuel, which is realized by its enrichment with hydrogen produced using the solar energy-supported electrolysis process, as well as application of post-combustion carbon dioxide separation. Results of the performed analysis suggest profitability of transition from fossil into the hydrogen-enriched fuel mixture, with significant rise in operational parameters of the system following increase in the hydrogen content. Nevertheless, utilization of the carbon dioxide separation leads to vital soar in internal energy demand, causing vital loss in operational and economical parameters of the analyzed system.

The development of combustion systems construction is associated with the possibility of increasing the thermal or overall efficiency of an internal combustion engine. The combustion systems currently in use (mainly related to direct fuel injection) are increasingly being replaced by hybrid systems, including direct and indirect injection. Another alternative is the use of prechambers in new combustion systems. This article concerns the thermodynamic aspect of this issue – namely, the assessment of the inter-chamber flow of a marine engine equipped with a prechamber combustion spark ignition system. The research was carried out using mainly one-dimensional simulation apparatus, and detailed analyses were presented using three-dimensional modeling. The tests included the engine model at medium load. Differences in mass flows were shown at different diameters and different numbers of holes from the preliminary chamber (while maintaining the same cross-sectional area). Similar values of excess air coefficient during ignition of the fuel dose in the prechamber were observed, which resulted in changes in the flow between the prechamber and the main chamber. The differences in mass flow affected the temperatures achieved in the individual combustion chambers. Based on three-dimensional analyses, the mass transfer rate between the chambers and the temperature distribution were assessed during fuel ignition initiated in the prechamber.

The article describes the results of combustion of a mixture of PCOME (purified cooking oil esters) and bioethanol in the compression ignition Perkins 1104C-44 engine. The engine was prepared for use with the classic type of fuel – diesel oil, not biofuels. That is why bioethanol was added to ester in tests so that the basic physicochemical properties of the obtained mixture were as close as possible to diesel fuel. Thanks to this, the use of such fuel in the future would not require reworking or adjusting the settings of selected elements of the engine power supply system. During this case study, the engine performance and heat release rate were analyzed. For comparison, tests were carried out while powering the engine with ester fuel, 10 and 20 per cent mixtures of bioethanol and PCOME. The speed and load characteristics for each fuel were determined. This article presents selected characteristics where the biggest differences were noticed.