• Analysis of antifriction additives to lubricants materials

    pg(s) 32-33

    The article is devoted to the analysis of the most used additives for lubricants. The principle of their operation and the result of their work are considered. The effect of additives on the structure of surface layers on the surface of friction pairs is est imated. The analysis showed the use of only a limited number of principles of the action of antifriction additives. Theoretically promising antifriction additives for base oils, relevant for use in railway transport, have been proposed.

  • Gaz diesel engine operating modes and environmental efficiency analysis

    pg(s) 30-31

    The article discusses the benefits of converting diesel to gaseous fuels, such as reducing the toxicity of engine exhaust gases, fuel costs and noise. It is also noted that the conversion of a gas diesel engine is technically simple and, if necessary, it is possible to operate on diesel fuel. The main focus is on improving the efficiency of the diesel engine by adjusting the fuel mixture so that the power of the gas-diesel engine and the diesel engine is the same under all load conditions. The influence of the explosive properties of fuel and its dosage on the characteristics of gasoline is estimated.

  • Energy and exergy evaluation of co2 closed-cycle gas turbine

    pg(s) 143-146

    This paper present energy and exergy evaluation of CO2 closed-cycle gas turbine process. The most important operating parameters of the whole observed cycle, as well as of each of its constituent components are presented and discussed. In the observed process, produced useful mechanical power for the power consumer drive is equal to 5189.78 kW, while the energy efficiency of the whole cycle is equal to 36.6%. Heat Regenerator is a crucial component of the observed process – without its operation energy efficiency of the whole cycle will be equal to only 16.91%. From the exergy aspect, Turbocompressor (TC) and Turbine (TU) shows good performances because its exergy efficiencies are higher than 90%. Regenerator exergy efficiency could be increased by lowering the temperature of the ambient in which analyzed CO2 closed-cycle gas turbine operates.

  • Initial design of an internal combustion engine for a range extender unit for electric vehicles

    pg(s) 108-111

    The present paper is focusing on a basic research for an initial design of an internal combustion engine for use in a range extender unit for an electric vehicle. The paper introduces a short description of the power train concept as well some interesting points, problems and challenges during the design process of the internal combustion engine. Some of them are connected with a proper selection of the engine configuration (number of the cylinders, their configuration, etc.), a determination of the engine main parameters (bore and stroke) and how they affect the engine operation and performance. Different parametric models are used and some output results are presented.

  • Alternative fuels for public transport vehicles – actual trends

    pg(s) 105-107

    Strategies for sustainable transport, and consequently sustainable mobility, require the use of cleaner vehicles without harmful emissions. The use of alternative fuels contributes to realization of set strategies and different types of alternative fuels are increasingly present in the transport sector. There is great potential in the use of alternative fuels in public transport systems, since this mode of transport plays a very important role in sustainable mobility. The aim is to replace the conventional bus fleets with vehicles with newer and cleaner technologies. Within this paper, alternative types of fuels used in public bus transport will be presented, as well as practical examples of the application of these modes of transport.

  • Indexes of gas engine converted from a tractor diesel

    pg(s) 71-73

    The experience of foreign companies on conversion of diesel vehicles for natural gas operation was analyzed. The results of computer simulations of the gas engine and diesel duty cycle were presented. The features of the gas engine power system converted from the D-243 tractor diesel are shown. The efficiency of the entire range of speed and load modes of a gas engine converted from D-243 diesel to run on natural gas has been experimentally confirmed by reducing the compression ratio from 16 to 12 and equipping it with a gas supply system and ignition system. Its effective power is close to that of a base diesel engine, equivalent to a specific fuel efficiency of up to 25% higher than that of a diesel engine. There is no carbon black in the exhaust gas of the gas engine. The emissions of certain harmful substances in some modes of operation of the gas engine are higher than that of the diesel, but the total toxicity of the exhaust gases resulting from carbon monoxide in the gas engine is 1.96 times lower than that of the diesel.

  • The possibility and analysis of using gas as an alternative fuel in the diesel engine

    pg(s) 68-70

    the article considers the possibilities of diesel engine operation on gaseous fuels, as well as their advantages over standard engines. The focus is on the possibility of running effectively the gas-diesel cycle so that it is brought to the processes occurring in the engine with forced ignition as close as possible. The article also discusses the issues related to optimization of the processes occurring in the gasdiesel engine, which will bring the gas-diesel cycle close to the petrol-running cycle. There are also identified ways to improve the economic and environmental performance of the diesel engine

  • Energy and exergy analysis of deaerator from combined-cycle power plant

    pg(s) 64-67

    Energy and exergy analysis of deaerator from combined-cycle power plant is presented in this paper. The deaerator is analyzed in three operating regimes and in various ambient conditions. The lowest deaerator energy loss of 525.60 kW and the highest energy efficiency of 78.21 % are obtained for the lowest water temperature at the deaerator outlet – in the same operating regime is obtained the lowest deaerator exergy efficiency. Decrease in the ambient temperature resulted simultaneously with an increase in deaerator exergy destruction and with increase in exergy efficiency. Deaerator exergy efficiency in each operating regime and for each observed ambient temperature significantly varies (from 13.82 % to 45.94 %). From the efficiency aspect, deaerator energy and exergy analysis show diametrically opposed results in two observed operating regimes.

  • Investigation of the influence of fulleren-containing oils on tribotechnical characteristics

    pg(s) 34-37

    The influence of fullerenes’ soot concentration, which added to oil М10г2к on few tribotechnical characteristics «steel-steel» was investigated. It was found, that optimal volume of fullerene soot in the oil was 0,1% of the weight. At this level of concentration can be seen the lowest values of coefficient of friction – 0,045, and intense of linear wearing – 2,7×10-9. Through optical investigation the participation of fullerene soot in surface forming mechanism and saturated with carbon was confirmed, it provided an increase in tribotechnical characteristics of the samples.

  • Methodology for static tuning of the HEV fuel flow measuring system

    pg(s) 30-33

    The modern automobiles are subject of more stringent requirements [1] corresponding to power, torque, fuel economy and ecology legislations, which is led to designing of new power sources and constructions, such as the hybrid electric vehicles (HEV). They are moving by the energy [2], which is ensured by the internal combustion engine (ICE) and the battery. The main factor in this area is the HEV fuel system, which is controlled by the electronic control unit (ECU) [1]. The electronic control of the Spark Ignition Engines (SI engines), as well as the Direct Ignition Engines (DI engines) is based on the certain sensors signals, program maps and management algorithms. The result in this electronic control is the management of the fuel injectors. The management of the fuel injectors consists in the start of injection, injection duration, number of injection events, injection advance, injection pressure etc. Moreover, the fuel consumption and fuel efficiency are the main factors, which are determining the HEV advances. The learning and measuring the HEV fuel consumption, as well as, the conventional automobiles, is the ground for achievement of quality results in the education of the automotive engineers, as well as for obtaining of scientific researching for developments and innovations. Significant meaning in this concept has the real, live and practical performance with the help of testing equipment and test-benches. This paper renders the methodology of static tuning the Fuel Flow Measuring System EFMS100 on the test bench SAV-1 with the support of controller Matrix MIAC MI0245 and Flowcode 7 software.

  • The change in energy flow streams for main marine propulsion steam turbine at different loads

    pg(s) 26-29

    This paper present analysis of energy flow streams through the main steam turbine (the turbine is used for commercial LNG carrier propulsion) at three different loads. An increase in the propulsion plant (and proportionally increase in the main turbine) load resulted with an increase in energy flow streams and with an increase in the amount of water droplets inside steam at the main turbine outlet. Analyzed turbine has three steam extractions which opening as well as the amount of energy flow stream delivered through each extraction, significantly differs at various loads. The analysis shows that the highest energy flow stream consumers from the main turbine are deaerator and high pressure feed water heating system.

  • Speciation of C5-C11 hydrocarbons generated by the HCCI gasoline exhaust gas engine

    pg(s) 132-133

    HCCI , SI HYDROARBONE SPECIATION GDIA qualitative and quantitative analysis of toxic but currently non-regulated hydrocarbon chemical species ranging from C5 – C11 was studded which is generated from a modern gasoline direct injection (GDI) engine by using gas chromatography-mass spectrometry (GC – MS). The GDI engine has been operated under different engine speeds and different engine modes (SI and HCCI modes). HCCI has the ability to operate on lean combustion which leads to the reduction in engine pumping losses, and fuel consumption However, HCCI mode has a high levels of unburnt HCs which leads to present heavier species such as Toluene, which is presented in higher concentrations under stoichiometric HCCI engine operation mode, while species such as , benzene, are mainly found in the engine exhaust during SI engine operation, Engine speeds has high impact on engine tail pipe emissions for both engine modes.. increasing engine speed leads to higher concentration in
    Benzene species while toluene was decreased and presented in higher concentration at low engine speed for both engine modes.