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Content available Synthetic automotive fuels
EN
The article explains the differences between synthetic fuels of first and second generation. The potential of e-fuels to reduce GHG emissions was indicated. The application requirements that synthetic fuels need to meet in order to be used for powering internal combustion engines have been described. The possibility of using synthetic fuels as "drop-in" fuels, in blends with conventional petroleum-derived fuels as well as by themselves was discussed. E-fuels developed and optimized to power compression ignition and spark ignition engines were characterized. The possibilities of synthetic fuels to reduce emissions of regulated and unregulated exhaust components and to improve the work and operational parameters of the engine were also analyzed using the research carried out so far as basis. At the end of the article, forecasts for synthetic fuels development and applications were presented in the form of a SWOT analysis.
EN
The article presents the concept of a maintenance-free inspection station intended for conducting drive-thru tests of commercial vehicles. The main purpose of building this type of diagnostic line is to carry out non-invasive, preliminary tests of heavy-duty vehicles entering the vehicle service area in terms of parameters affecting the safety of their operation in relation to the applicable standards. The main parameter to be assessed will be the concentration of toxic exhaust components, measured using remote sensing methods. In addition, the proposed diagnostic line can be supplemented with additional remote measurement systems, such as, for example, systems for assessing the condition of vehicle lighting, loads on individual axles and individual wheels of the vehicle, tire pressure, thermal load of the brake system, as well as a system for detecting leaks of fluids from the vehicle. Based on the carried out work, it has been shown that using the current specialist knowledge and the components of measurement systems available on the market, it is possible to develop an innovative diagnostic line using remote measurement methods.
EN
Internal combustion engines represent the largest share of motor vehicle propulsion types. Despite the introduction of alternative drives (hybrid and electric), combustion engines will continue to be the main factor in the development of transport. Therefore, work related to their technological development and reduction of their harmful effects on human health and the environment is required. The development of internal combustion engines can be seen in two directions: technological changes resulting in increased efficiency of such engines and the second direction connected with limitation of exhaust gas emission. The present work is included in the second direction of research interests and concerns the analysis of various operating conditions of internal combustion engines. The operating states, both static and dynamic, determine the operational properties of internal combustion engines, such as fuel and energy consumption as well as pollutant emissions. Sofar, such operating conditions have only been mapped on a chassis dynamometer in various homologation tests. The course of the type approval test was known and the conditions of measurement were also known, which made it impossible to introduce a random factor into such tests. Currently, these properties are determined in tests performed in real vehicle operating conditions – RDE (Real Driving Emissions). Such tests are representing real operating conditions of motor vehicles. Limitations for performing tests in real traffic conditions are, apart from formal requirements concerning the duration and distance of individual parts, the dynamic conditions of vehicles determined by the speed and acceleration of the vehicle. The study analyzed the properties of vehicle speed processes and engine operating states in the RDE test, taking into account its individual phases – driving in urban, rural and motorway conditions. Engine operation states are the processes of the engine rotational speed and its relative torque. It was found that the dynamic properties of the vehicle speed process are much more significant than the engine operating states. It was also found that the road emission of pollutants in the RDE test, which is the property of vehicles measured in the test, the motorway phase properties have greatest impact.
EN
Pollution of the environment is a global phenomenon. The lack of specific actions to reduce environmental pollution can lead to an increase in the average temperature of the Earth's air and to global consequences. One of the important sectors affecting environmental pollution is transport, including road transport. Currently, intensive legislative and construction works are underway to reduce the emission of harmful substances from road transport. Meeting the requirements imposed by the European Union makes it necessary not only to make structural changes to combustion units or exhaust aftertreatment systems, but also to use additional systems supporting the operation of the main engine. This group includes, among others, Mild Hybrid propulsion systems and classic hybrid systems. Their application is to affect not only the possibility of reducing the swept volume of a combustion unit, while maintaining its operational parameters, but also to reduce the emission of harmful substances of exhaust gases. The conducted research and its analysis indicate the legitimacy of using a newer vehicle equipped with a modern propulsion system, i.e. Mild Hybrid, in real conditions. In the case of toxic emissions of exhaust gases, a difference in emissions of individual components is noticeable, depending on the chosen driving mode. However, it is worth mentioning the difference in the emission of nitrogen oxides and the number of particulate matters. Their emission is reduced in relation to a vehicle using a classic powertrain. The use of a modern propulsion system also improves reliability. The tested Mild Hybrid vehicle does not use a conventional alternator and starter. This eliminates the elements that are prone to damage in prolonged operation. This is an unquestionable advantage when taking into account the operation of the vehicle.
EN
To reduce exhaust NOx and smoke, it is important to measure flame temperature and soot amount in combustion chamber. In diesel combustion it is effective to use the two-color method for the measurement of the flame temperature and KL factor, which is related with soot concentration. The diesel flame was directly and continuously observed from the combustion chamber at running engine condition by using a bore scope and a high-speed video camera. The experimental single cylinder engine has 2.0-liter displacement and has the ability with up to five times of the boost pressure than the naturally aspirated engine by external super-charger. The devices of High Boost, Wide Range and High EGR rate at keeping a relatively high excess air ratio were installed in this research engine in order to reduce exhaust NOx emission without smoke deterioration from diesel engines. The video camera nac GX-1 was used in this study. From observed data under the changing EGR rates, the flame temperature and KL factor were obtained by the software of two-color method analysis. The diesel combustion processes are understood well by analyzing high-speed movies of the diesel flame motion and its temperature. The NOx and smoke are mutually related to maximum flame temperature and also it is possible to reduce simultaneously both NOx and soot emissions by high EGR rate in a single cylinder diesel engine.
EN
Fuel consumption achieved in the New European Driving Cycle (NEDC) could be 50% lower than the fuel consumption in real driving conditions and in the case of emissions of regulated toxic compounds the differences could even be much greater. In order to bring the results achieved in official tests closer to real life figures, the European Commission introduced in 2017 the Worldwide Harmonized Light Vehicles Test Procedure (WLTP), which replaced the NEDC. In this article the results of fuel consumption and exhaust emissions for 3 cars fitted with engines of the same displacement but with direct and indirect gasoline injection, determined according to the NEDC and WLTC were presented. The results show that the effect of driving cycle on the fuel consumption is equivocal - for one car, fuel consumption was higher in the WLTC; for the other one in the NEDC; and for the third one, fuel consumption achieved in both driving cycles was practically the same. Emissions of regulated exhaust compounds, except for THC, obtained in the WLTC were higher than in the NEDC driving cycle.
EN
The manuscript presents a comparative analysis of the performance and emission characteristics of a compression ignition engine equipped with a Common Rail injection system. The engine is fueled with diesel-biodiesel mixtures containing 25% and 50% share (by volume) of renewable components. Conventional diesel is used as a reference. Turkey lard and rapeseed oil are used as raw materials and subjected to the single-stage transesterification process to obtain methyl esters. The experiments are performed on a medium-duty, turbocharged, inter-cooled, Common Rail Direct Injection (CRDI) diesel engine. This study concentrates on one engine speed of 1500 rpm, typical for gen-set applications, and mid-load range from 100 Nm to 200 Nm. The scope of measurements covers the analysis of exhaust gasses concentration and engine efficiency parameters. In addition, the in-cylinder pressure measurements are performed in order to provide insight into the differences in combustion characteristics between examined fuel mixtures. The study reveals that the addition of the renewable component to fuel mixture positively affects a number of examined performance parameters as well as de-creases the concentration of the examined toxic exhaust components, in the majority of cases.
EN
The article analyzes the environmental costs which consisted of determining the annual cost for gases and particles released into the atmosphere by city buses meeting the Euro VI norm. To this end, exhaust emissions of a city bus equipped with a conventional drive system were performed. The vehicle had a length of 18m and was powered by a CI engine with a swept volume of 10,5 dm3, with a maximum power of 240 kW. In order to measure the ecological indicators, tests were performed in real driving conditions using the PEMS system. The apparatus made it possible to measure the concentration of gaseous compounds and particulate matter in the exhaust, which made it possible to determine the road exhaust emissions of the tested vehicle. The research was carried out on a test route including urban and suburban roads in accordance with legislative guidelines. The measurements showed that the bus met the exhaust emission limits determined on the basis of measuring windows defined in relation to the work generated by the drive system. In addition to information on the emissivity of the vehicle, the annual emissions from city buses meeting the Euro VI standard in Poland were also estimated. The information contained in the central vehicle register for the number of vehicles registered in Poland that meet the latest emission standards has been used for this purpose.
EN
Multi-role aircraft as a technical object of a certain functional purpose and operating characteristics resulting from its construction, affects the operating environment mechanically, as a source of disturbance of the medium in which it moves and chemically, by generating the emission of harmful substances resulting from the need to use consumable fuels. Operation of multi-role aircraft, in contrast to civil aircraft, is characterized by high volatility of flight data resulting from the diversity of performed tasks. Therefore it seems desirable to attempt the ecological evaluation of the drive in terms of emissions on the basis of a dedicated test for a particular group of aircraft. An attempt at such an assessment is presented in this article.
EN
Public concern and complaints regarding ambient air in zones of dense traffic pertains to two compounds of nitrogen, nitrogen dioxide (NO2) and ammonia (NH3); both are toxic and strongly irritant, such that legal limitations are under discussion. This paper contributes to measuring methods as already in part proposed by GRPE subgroup WLTP-DTP (Worldwide Light Duty Test Procedures – Diesel Test Procedures) for NO2. Despite legally lowered NOx emission levels, lumping both, NO2 and NO, levels of NO2 have risen in cities and agglomerations as a result of both, deployed catalytic exhaust after-treatment devices and low sulphur Diesel fuels. In present tests two different combinations of NO2 measuring methods as proposed by WLTP were checked on Diesel cars for practicability in handling and accuracy. These integral, indirect methods (NO2 = NOx – NO) have been found as useful tools for estimate of NO2 and with use of appropriate analyzers a satisfactory accuracy was attained. Furthermore, attention was brought to ammonia (NH3) emitted by gasoline engines with three way catalysts (TWC) which ought not to be ignored while on the other hand SCR systems for Diesel engines are strictly regulated. Emission levels of more recent TWC turned out to be mostly below 20 ppm NH3. Vehicle of older technology exhibited significantly higher levels, about 10 times more. As chemical reactions depend on pressure and temperature (= i.e. flow condition in CVS-tunnel) as well as concentrations, doubts need to be considered on accuracy of results based on chemical reactive substances. Nevertheless, clear tendencies regarding changes of concentrations of NO2 and NH3 along the path-way could not be observed.
EN
New test procedures for determining exhaust emission from passenger vehicles will be introduced in 2017. For several years, the European Commission has been developing new procedures, which aim is to perform tests in road conditions. The purpose is to determine the real values of emissions, which are not always reflected by the level of emissions obtained in the laboratory. Proper and accurate procedures for determining emissions in real traffic conditions (RDE – Real Driving Emission) have not yet been approved (as opposed to Heavy Duty Vehicles for which such conditions already exist), but there are proposals that are currently being analyzed by major research centers in Europe. There are many differences between those proposals such as determining road emission or research methodology related to emission measurement of hydrocarbons. The work compares the results of emissions measured in road tests using the latest legislative proposals related to passenger cars. The results are shown in relation to the used measurement method: classic method of determining exhaust emission; uses all measurement data determining the mass of harmful compounds and distance travelled during the test; method of averaging the measuring windows (MAW – moving average windows), also in the literature called EMROAD method, which determines the measurement windows (on the basis of carbon dioxide emissions from the WLTC test) and on its basis determines the road emission in RDE test; generalized method of instantaneous power (Power Binning), known in the literature as CLEAR – Classification of Emissions from Automobiles in Real driving, determines road emissions on the basis of generalized instantaneous power during the RDE test.
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