Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 371

Liczba wyników na stronie
first rewind previous Strona / 19 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  combustion engines
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 19 next fast forward last
PL
Osady tworzone na powierzchniach różnych wewnętrznych elementów tłokowych silników spalinowych i układów z nimi współpracujących stanowią niepożądane zjawisko, narastające wraz z czasem eksploatacji silników i zagrażające ich poprawnemu działaniu. Powstawanie osadów w wyniku przebiegu procesów wtrysku paliwa, tworzenia mieszanki paliwowo-powietrznej i jej spalania w tłokowych silnikach spalinowych jest zjawiskiem normalnym. Dopiero na początku XXI wieku rozpoczęto szerokie, wielokierunkowe badania mające na celu ustalenie nie tylko przyczyn powstawania osadów, mechanizmów ich tworzenia i czynników sprzyjających procesom przyrostu osadów, ale także określenie składu chemicznego różnych grup osadów. Potrzeby takich badań wynikały z konieczności spełniania przez silniki sukcesywnie zaostrzanych przepisów w zakresie ochrony środowiska naturalnego człowieka, a to wiązało się z wprowadzaniem coraz bardziej złożonych konstrukcji silników oraz strategii sterowania procesami precyzyjnego, dzielonego na części wtrysku paliwa do komór spalania silników i zaawansowanych algorytmów sterujących procesami spalania w zależności od systemu spalania oraz przeznaczenia silnika. Okazało się jednak, że współdziałanie coraz bardziej złożonych technologii i rozwiązań silników, a zwłaszcza układów wtrysku paliwa, może być w sposób istotny zaburzane tworzonymi w nich osadami. Coraz bardziej skomplikowane konstrukcje silników oraz rosnąca dokładność wykonania współpracujących ze sobą elementów wymuszają konieczność wielokierunkowego badania szkodliwych osadów. Identyfikowanych jest coraz więcej czynników wpływających na tworzenie osadów, co prowadzi do opracowywania coraz bardziej złożonych klasyfikacji i podziałów osadów ze względu na ich rodzaj, skład i postać. Równocześnie poszukiwania sposobów dalszego obniżania emisji składników szkodliwych do atmosfery i poprawy sprawności silników wymuszają dalsze zmiany w konstrukcji zarówno silników, jak i samych pojazdów. Zwiększające się ciśnienie i temperatura procesów spalania silnikach w połączeniu ze zmianami ich tradycyjnego cyklu pracy wpływają na zmiany wymagań stawianych paliwom silnikowym. W konsekwencji powyższe zmiany mają wpływ zarówno na skład chemiczny, jak i morfologię tworzonych w silnikach osadów. Wielkość tworzonych osadów koksowych może zaburzać procesy rozpylania paliwa, napełniania komór spalania silnika, zawirowania ładunku w komorach spalania, a w konsekwencji wpływać na sprawność napełniania komór spalania oraz na jakość tworzenia mieszanki paliwowo-powietrznej. Doprowadziło to do opracowania wielu znormalizowanych metod oceny wielkości osadów. Ustalono przy tym, że w przypadku silników ZI osadami najbardziej zagrażającymi ich poprawnej pracy, w rozumieniu zachowania deklarowanych przez producentów osiągów w czasie oraz walorów użytkowo-eksploatacyjnych, są te, które tworzą się w komorach spalania, na zaworach dolotowych, w kanałach dolotowych i na końcówkach wtryskiwaczy paliwa. W przypadku silników ZS najbardziej niebezpieczne są osady koksowe (węglowe) tworzone na zewnętrznych powierzchniach końcówek rozpylaczy wtryskiwaczy oraz wewnątrz kanalików wtrysku paliwa rozpylaczy. W Europie obligatoryjne procedury oceny wielkości różnych osadów koksowych powstających na różnych elementach, zarówno w silnikach ZI, jak i ZS, opracowywane są w ramach grup roboczych CEC (Co-ordinating European Council for the Development of Performance Tests for Transportation Fuels, Lubricants and Other Fluids). W teoretycznej części pracy opisano problemy związane z osadami tworzonymi w tłokowych silnikach spalinowych oraz w ich układach paliwowych. Omówiono standardowe oraz niestandardowe silnikowe i analityczne metody zarówno ilościowej, jak i jakościowej oceny osadów. Przedstawiono znaczenie obecnie stosowanych metod ocen dla tworzenia klasyfikacji osadów. Wskazano zakres stosowania oraz przydatność metod do określenia zagrożeń, jakie stwarzają różnego typu osady dla funkcjonowania silnika, jak i ustalenia przyczyn ich powstawania, w tym w szczególności związanych ze składem stosowanych paliw i smarowych olejów silnikowych. Przedyskutowano wpływ składu paliw, jak również konstrukcji silników i warunków ich eksploatacji na tworzenie różnych osadów zarówno w samych silnikach, jak i w układach wtrysku paliwa. Wskazano możliwe przyczyny powstawania szkodliwych osadów. Podkreślono też ogromne znaczenie opracowywania i stosowania nowoczesnych dodatków do paliw kontrolujących i przeciwdziałających tworzeniu szkodliwych osadów silnikowych. W części doświadczalnej zaprezentowano wyniki badań prowadzonych w ramach projektów badawczych i prac statutowych w Instytucie Nafty i Gazu – Państwowym Instytucie Badawczym. Niniejsze wyniki dotyczą: • nieporównywalności ocen właściwości detergentowych paliw w różnych, znormalizowanych testach silnikowych; • wielokierunkowych ocen wpływu różnych dodatków detergentowo-dyspergujących na tworzenie się szkodliwych osadów podczas testów silnikowych; • wpływu sposobu uszlachetniania paliw na procesy ilościowego i jakościowego tworzenia osadów w tłokowych silnikach spalinowych; • oceny wpływu wybranych związków chemicznych stanowiących zanieczyszczenia zawarte w paliwach na procesy powstawania osadów w silnikach i układach wtrysku paliwa; • oceny wpływu różnych struktur związków chemicznych stanowiących zanieczyszczenia zawarte w paliwach i biopaliwach na procesy powstawania osadów w silnikach i układach wtrysku paliwa; • wielokierunkowych badań wpływu biokomponentów zawartych zarówno w benzynach, jak i olejach napędowych na tendencje do tworzenia osadów silnikowych; • wielokierunkowych badań wpływu starzenia FAME zawartego jako biokomponent w oleju napędowym na tworzenie szkodliwych osadów w silnikach i układach wtrysku paliwa.
EN
The undesirable deposits forming on the surfaces of various internal parts of reciprocating internal combustion engines and the systems operating in conjunction with them worsen during the operation of the engines and threaten their proper functioning. The deposits form as a normal result of the processes of fuel injection and creating and combusting the fuel–air mixture in engines. It was not investigated until the beginning of the 21st century, when extensive multi-directional research began not only to identify the causes of these deposits, the mechanisms behind their formation, and the factors leading to deposit growth, but also to determine the chemical composition of various groups of deposits. Such research became necessary because engines must comply with gradually tightening regulations on environmental protection, necessitating the introduction of increasingly complex engine designs and strategies for controlling the processes of precise and divided fuel injection into the combustion chambers and advanced algorithms for controlling the combustion processes according to the combustion system and the purpose of the engine. However, it became apparent that the co-functioning of the increasingly complex engine technologies and solutions, particularly of fuel injection systems, may be significantly disturbed by the deposits forming inside them. More and more complicated engine designs with tighter and tighter tolerances of the working parts necessitate the multi-directional testing of harmful deposits. An increasing number of factors affecting deposit formation are being identified, which leads to the development of increasingly complex classifications and subdivisions of deposits according to their type, composition, and form. At the same time, the search for lower emissions and greater engine efficiency is driving further mechanical changes in engines and vehicles. The higher temperatures and pressures connected with these changes are likely to impact the fuel being handled within the fuel and combustion systems. Such effects will inevitably cause the deposit chemistry and morphology to change. The size of the coke deposits produced may disturb the processes of fuel atomization, of filling the engine combustion chambers and swirling the charge, and in consequence may affect the efficiency of filling and the quality of the fuel–air mixture. These problems led to the development of a number of standardized and unstandardized methods for assessing the size of deposits. It was found that in the case of SI engines, the deposits that most endanger correct engine operation are those which are formed in the combustion chambers, on the inlet valves, inlet ducts, and fuel injector tips. The most common sign of deterioration caused by deposits is the loss over time of the performance, usability, and operational value which were originally declared by the manufacturer. In the case of CI engines, the most dangerous are coke (carbon) deposits formed on the external surfaces of the fuel injector nozzle tips and inside the injector nozzle orifices. In Europe, mandatory procedures for assessing the size of different coke deposits formed on different components in both SI and CI engines are being developed by the Coordinating European Council for the Development of Performance Tests for Transportation Fuels, Lubricants, and Other Fluids (CEC). The theoretical part of this publication reports the problems of the deposits produced in reciprocating internal combustion engines and their fuel systems. It discusses standard and non-standard engine test methods for both quantitative and qualitative assessment of deposits and presents the significance of the assessment methods which are currently used for the classification of deposits. The publication also presents the scope of application and the usefulness of methods for determining the threats posed to the functioning of an engine by various types of deposits and methods for identifying the causes of deposit formation, in particular those related to the composition of the fuels and lubricating oils used. The effects which fuel composition and the engine’s construction and operating parameters have on various engine deposits, the possible causes of deposit formation, and the importance of modern deposit control additives and high-technology solutions in counteracting this detrimental phenomenon are also all discussed. The experimental part presents the results of research carried out at the Oil and Gas Institute – National Research Institute concerning: • the incomparability of measurements of fuel performance obtained from various engine tests, • studies on the influence of various deposit control additives on the formation of harmful engine deposits during engine tests, • the influence of fuel treatments on the deposit formation processes in internal combustion engines (described qualitatively or quantitatively), • determination of the impact which various chemical compounds, serving as contaminants within the fuels, have on deposit formation in internal combustion engines and fuel injection systems, • determination of the impact that various chemical structures of the compounds within the fuels and biofuel blends have on deposit formation in internal combustion engines and fuel injection systems, • studies on the influence of bio-components contained in both petrol and diesel fuels on tendency for deposits to form in internal combustion engines, and • multidirectional studies on the impact of FAME degradation processes in biodiesel fuel blends on the formation of harmful engine deposits.
2
Content available Modelling of the low-pressure gas injector operation
EN
In recent years, there has been a growing interest in alternative sources of power supply for internal combustion engines. Lique-fied petroleum gas injection systems are among the most popular. It becomes necessary to know mathematical descriptions of the opera-tion of individual components. The article presents a mathematical model that describes the operation of the low-pressure gas injector. Valtek plunger injector was chosen as the test object. The mathematical description includes three parts, i.e. electric, mechanical and pneumatic. The electrical part describes the generation of electromagnetic force by a circuit with a coil, in the mechanical equilibrium equa-tion of forces acting on the plunger, and in the pneumatic part the air pressure on the plunger. The calculations were performed in the Matlab/Simulink environment, creating current waveforms, acting forces and plunger displacement. Correctness of mathematical descrip-tion and determined in the course of opening and closing time calculations were related to the values declared by the manufacturer, show-ing differences below 3%. The presented mathematical model can be modified for other injector design solutions.
EN
The article presents research results referring to the influence of supply pressure on the functional parameters of the impulse low-pressure gas-phase injector. The study was done on the original stand for flow test of gas-phase injectors. In the indirect evaluation, with the initial parameters and the length of the forced impulse, the current line, acceleration and pressure sensor courses were used. Apart from the volumetric flow rate, the analysed parameters were the time periods of the injector opening and closing process. Those time segments were composed of response time and opening/closing time, the sum of which gives time of full opening. Functional relationships describing the volumetric flow rate, time of full opening and closing are presented, which are helpful not only in comparative tests of different injectors, but also in modelling the operation of gas injector or algorithms of gas supply control system. The reference to the volumetric flow rate allowed to indicate possible causes of variability of this parameter depending on the supply pressure.
EN
The constructions of today's of internal combustion engines used in PC category vehicles require the use of exhaust gas aftertreatment systems in order to meet the emission standards. The oxidation or reduction reaction processes of toxic compounds in the system is directly related to the temperature of the medium and determines the operating efficiency. The temperature value is of particular importance in the spark-ignition engine, in which the variations due to the quantitative regulation of the fuel-air mixture are greater. The temperatures obtained may be low especially in urban conditions, due to road congestion, in which the engine operates at idle generating exhaust gas at low temperature. The article presents exhaust system temperature tests of a modem SI engine depending on the operating point in a simulated real drive cycle through the Poznań agglomeration, previously recorded during tests in accordance with the RDE procedure. The temperature measurement was carried out upstream and downstream of the catalytic converter, as well as at the location corresponding to the end point of the vehicle exhaust system. The obtained results have been compared to maximum temperature of exhaust sample for PEMS analyzers.
PL
Konstrukcje dzisiejszych silników spalinowych stosowanych w samochodach kategorii PC wymagają zastosowania układów oczyszczania spalin w celu spełnienia norm ich emisji. Procesy reakcji utleniania lub redukcji toksycznych związków w układzie wylotowym są bezpośrednio związane z jego temperaturą i determinują możliwość ich realizacji. Wartość temperatury spalin ma szczególne znaczenie w silniku o zapłonie iskrowym, w którym zmiany wynikające z ilościowej regulacji mieszanki paliwowo-powietrznej są większe niż w silniku Diesla. Uzyskana temperatura układów oczyszczania spalin może być zbyt niska, szczególnie w warunkach miejskich, z powodu kongestii, w których silnik pracuje na biegu jałowym, bądź jest wyłączany przez system start-stop. W artykule przedstawiono badania temperatury układu wylotowego nowoczesnego silnika SI w zależności od punktu pracy w symulowanym rzeczywistym cyklu jazdy przez aglomerację poznańską, uprzednio zarejestrowanym podczas badań zgodnie z procedurą RDE. Pomiary temperatury przeprowadzono przed i za reaktorem katalitycznym, a także w miejscu odpowiadającym punktowi końcowemu układu wydechowego pojazdu. Uzyskane wyniki porównano z maksymalną temperaturą próbki spalin dla stosowanych analizatorów PEMS.
EN
Current trends in the high bypass ratio turbofan engines development are discussed in the beginning of the paper. Based on this, the state of the art in the contemporary turbofan engines is presented and their change in the last decade is briefly summarized. The main scope of the work is the bypass ratio growth analysis. It is discussed for classical turbofan engine scheme. The next step is presentation of reach this goal by application of an additional combustor located between high and low pressure turbines. The numerical model for fast analysis of bypass ratio grows for both engine kinds are presented. Based on it, the numerical simulation of bypass engine increasing is studied. The assumption to carry out this study is a common core engine. For classical turbofan engine bypass ratio grow is compensated by fan pressure ratio reduction. For inter turbine burner turbofan, bypass grown is compensated by additional energy input into the additional combustor. Presented results are plotted and discussed. The main conclusion is drawing that energy input in to the turbofan aero engine should grow when bypass ratio is growing otherwise the energy should be saved by other engine elements (here fan pressure ratio is decreasing). Presented solution of additional energy input in inter turbine burner allow to eliminate this problem. In studied aspect, this solution not allows to improve engine performance. Specific thrust of such engine grows with bypass ratio rise – this is positive, but specific fuel consumption rise too. Classical turbofan reaches lower specific thrust for higher bypass ratio but its specific fuel consumption is lower too. Specific fuel consumption decreasing is one of the goal set for future aero-engines improvements.
EN
The article presents the possibility of using self-learning control algorithms to manage subassemblies of an internal combustion engine in order to reduce exhaust emissions to the natural environment. In compression ignition (CI) engines, the issue of emissions mainly concerns two components: particulate matter (PM) and nitrogen oxides (NOx). The work focuses mainly on the possibility of reducing the emission of nitrogen oxides. It is assumed that the particularly problematic points when it comes to excessive emission of harmful substances are the dynamic states in which combustion engines operate constantly. In dynamically changing operating points, it is very difficult to choose the right setting of actuators such as the exhaust gas recirculation (EGR) valve to ensure the correct operation of the unit and the minimum emission of these substances. In the light of the above, an attempt was made to develop a selflearning mathematical model, which can predict estimated emission levels of selected substance basing on current measurement signals (e.g. air, pressure, crankshaft rotational speed, etc.). The article presents the results of the estimation of nitrogen oxides by the trained neural network in comparison to the values measured with the use of a sensor installed in the exhaust system. The presented levels of estimated and measured results are very similar to each other and shifted over time in favour of neural networks, where the information about the emission level appears much earlier. On the basis of the estimated level, it shall be possible to make an appropriate decision about specific settings of recirculation system components, such as the EGR valve. It is estimated that by using the chosen control method it is possible significantly to reduce the emission of harmful substances into the natural environment while maintaining dynamic properties of the engine.
EN
Regeneration of parts is the most correct form of use of worn out components and contributes, among others, to reduce CO2 emissions. In the case of elements of fuel injector systems, very high precision is required and such regeneration should be carried out using the original parts. It also requires testing on the original testing stands of these manufacturers, which very often characterized by the fact that it is not possible to perform a short test, which means that it is only possible to perform a time-consuming comprehensive test. An unquestionable advantage in some cases would be the possibility of preliminary verification of the correct operation of the regenerated subassembly without the need for a full time-consuming test. In the present situation, only after completing a time-consuming comprehensive test of the diagnosed element of the injection system, it is often necessary to carry out its disassembly, replacement or correction of one of the components and reassembly with the next time-consuming test. In the case of low unemployment in the labour market, this is extremely unfavourable, and it is often not possible to organize work in such a way that the diagnostic test of the subassembly takes place without the participation of an employee. On the basis of the analyses presented in this article, carried out in the research and development department in company whose employee is one of the co-authors, it can be stated that in the current situation on the labour market where skilled workers are required to work and for the development of science is the most purposeful recognition of the possibility of using vibroacoustic signals to shorten time of tests, which with a high probability may end in a negative result. The preliminary analysis carried out, show that limitation of diagnostic time can be over 35%.
EN
Limiting emissions of harmful substances is a key task for vehicle manufacturers. Excessive emissions have a negative impact not only on the environment, but also on human life. A significant problem is the emission of nitrogen oxides as well as solid particles, in particular those up to a diameter of 2.5 microns. Carbon dioxide emissions are also a problem. Therefore, work is underway on the use of alternative fuels to power the vehicle engines. The importance of alternative fuels applies to spark ignition engines. The authors of the article have done simulation tests of the Renault K4M 1.6 16v traction engine for emissions for fuels with a volumetric concentration of bioethanol from 10 to 85 percent. The analysis was carried out for mixtures as substitute fuels – without doing any structural changes in the engine's crankshafts. Emission of carbon monoxide, carbon dioxide, hydrocarbons, oxygen at full throttle for selected rotational speeds as well as selected engine performance parameters such as maximum power, torque, hourly and unit fuel consumption were determined. On the basis of the simulation tests performed, the reasonableness of using the tested alternative fuels was determined on the example of the drive unit without affecting its constructions, in terms of e.g. issue. Maximum power, torque, and fuel consumption have also been examined and compared. Thus, the impact of alternative fuels will be determined not only in terms of emissions, but also in terms of impact on the parameters of the power unit.
EN
The article presents the conditions for the use of ethyl alcohol as a component and a sole fuel for internal combustion engines. Methods of ethanol production, its properties and the benefits and risks associated with using it as engine fuel have been described. The variants of commercial ethanol fuels allowed by law have also been presented. Ecological aspects of the use of ethanol fuels for modern internal combustion engines were presented. The opinion was expressed that although ethanol is used in bulk as a component of gasolines, its use as a self-contained fuel is and probably will continue to be small in the near future.
PL
W artykule przedstawiono uwarunkowania stosowania alkoholu etylowego jako składnika oraz samodzielnego paliwa do silników spalinowych. Opisano metody produkcji etanolu, jego właściwości oraz korzyści i zagrożenia związane ze stosowaniem go jako paliwa silnikowego. Zaprezentowano dopuszczalne prawem warianty handlowych paliw etanolowych. Przedstawiono ekologiczne aspekty stosowania paliw etanolowych do współczesnych silników spalinowych. Wyrażono opinię, iż mimo, że etanol stosowany jest masowo jako komponent benzyn silnikowych, to jego zastosowanie jako samodzielnego paliwa jest i prawdopodobnie w najbliższej przyszłości będzie niewielkie.
EN
The article presents the compression-ignition engine test results of static operating states in driving tests: NEDC (New European Driving Cycle), RDE (Real Driving Emissions) and the Malta custom test cycle, developed at the Poznan University of Technology. The NEDC and Malta tests were carried out as drive cycle simulations on the engine test bench, the RDE test was carried out in the real driving conditions. The engine operating states are described by the physical quantities of speed and torque. For each of the tests, zero-dimensional characteristics of the values describing the engine operation states were determined, including: mean value and average standard deviation and coefficient of variation. Histograms of quantities describing the engine's operating states for considered tests and driving conditions were also determined. A large diversity of zero-dimensional characteristics of the quantities describing the engine's operating states for the considered driving tests and driving conditions was found.
EN
The article presents results of the studies on the charged, dual-fuel CI compression ignition engine fuelled with propane. The main goal of the studies was to fuel the engine so that the amount of energy provided with propane is possibly highest at the high efficiency, low emission of harmful exhaust constituents and proper combustion. As the studies conducted so far have shown, with the increase of energy from propane we observe crucial changes in the combustion process. As these changes may be a barrier in the further increase of energy, we decided to change the injection parameters of the diesel fuel. The changes introduced allowed for the 70% energetic contribution of gas fuel at the subsequent elimination of unfavourable phenomena. The fuel injection was realized divided into two doses. Both proportions and angle at the beginning of the injection for both doses were variable. The angle at the beginning of injection for the first dose was changed in a wide range and depended on the value of charging pressure. The angle at the beginning of injection for the second dose was changed in a much narrower range, mainly due to very clear changes in the nature of combustion process. The studies have been conducted for three values of charging pressure, namely 200; 400 and 600 [mbar], and also for the naturally aspirated version. Study results have been presented in a form of regulation characteristics for the angle of the beginning of injection of the pilot dose for the chosen charging variants, as well as volume and angle of the beginning of injection for the main dose. The obtained results show that the content of exhaust constituents for the dual-fuel CI engine depends highly on assumed regulations of injection parameters of the fuel dose initiating the ignition, as well as engine charging pressure.
EN
The article presents selected problems concerning tests of toxic exhaust emissions from engines of vehicles, mobile devices, engines used in gardening and construction works. For this group of engines, this type of testing is carried out primarily in laboratory conditions, however, variable load conditions during actual operation justify efforts to determine the level of emissions in real operating conditions. Research in real operating conditions for different engine categories becomes increasingly more standard, in this aspect, it is necessary to verify the state of knowledge and methodology in the aspect of testing engines of machines and mobile devices. The research performed by the authors was the first of this type using PEMS equipment, hence some conclusions and observations can be made from the obtained results. At present, the type approval procedures for the engine group in question do not account for emissions tests in real operating conditions, while also missing any description of a standardized research methodology. In addition, the engine group in question is not really suitable for testing in real conditions. An introduction to research aimed at developing an exhaust emission test methodology in real operating conditions of mobile device engines was included in the article.
13
Content available Modern drive systems of rail vehicles
EN
Rail vehicles are one of the sources of environmental pollution in the transport sector. Therefore, it is necessary to equip these vehicles with modern drive systems. This article concerns the issues of contemporary and future-oriented solutions of drive systems used in rail vehicles. The article analyzes energy storage possibilities including: electrochemical, mechanical and hydraulic accumulators. The conducted analyzes have taken into account the importance of how frequently they charge up, which dictates their possible applications. Characteristics of hybrid drive systems were presented, with particular emphasis on parallel systems of: hydrostatic, flywheels and electrochemical batteries. The analysis of energy flow control strategies in hybrid drive systems of railway vehicles has been made. In the summary, a solution was chosen that resulted in high conversion efficiency of the energy extracted from the vehicle's wheels.
EN
The article presents the exhaust emission results from a diesel engine in dynamic states of engine operation in the driving tests: NEDC (New European Driving Cycle) and Malta test, developed at the Poznan University of Technology. The NEDC and Malta tests were carried out as simulations on the engine test bench mimicking the driving tests conditions. The test results of the emission of carbon monoxide, hydrocarbons and nitrogen oxides obtained in each of the tests were presented. The dynamic states have been classified depending on the time derivative value of the torque and engine rotational speed. Both the positive and negative as well as zero time derivative values of torque and rotational speed were considered. Therefore, overall six types of dynamic states were analyzed. A high sensitivity of exhaust emission to various types of dynamic states was found. The exhaust emission sensitivity to dynamic states in the Malta test was found to be higher than for the NEDC test, although these tests have similar properties (average rotational speed and average torque). This is due to the fact that the NEDC test is created on the basis of the similarity of zero-dimensional characteristics of the car's speed characteristic, whereas the Malta test was designed in accordance with the principle of faithful representation in the time domain of the NEDC speed curve.
EN
The subject of this article is a comparative analysis of exhaust emissions for: HC (hydrocarbons), CO (carbon monoxide), CO2 (carbon dioxide), NOx (nitrogen oxides) from a passenger vehicle and a motorcycle in laboratory conditions on a dynamometer station. The first vehicle category was represented by a compression-ignition engine with a displacement volume of 1.3 dm3 and a power of 66 kW. The exhaust aftertreatment system included a catalytic converter and a particulate filter. The second category was a motorcycle, equipped with an engine with a displacement of 0.7 dm3 and a maximum power of 55 kW. The two-wheeled vehicle was equipped with a three-way catalytic converter. Speeds were modeled on the European type approval test - NEDC (New European Driving Cycle). In order to conduct a comparative analysis of exhaust emissions and fuel consumption from vehicles of different categories, the obtained results were presented in the form of emissions converted into passenger-kilometers (g/pkm). The research used modern equipment belonging to the PEMS (Portable Emissions Measurement Systems) group of devices. The analyzes carried out enable the decision making on which vehicles have a greater environmental impact due to their exhaust emissions, taking into account the distance and the number of passengers carried.
EN
Comparative analysis of combustion and hybrid propulsion unit in aviation application in terms of emission of harmful compounds in the exhausts emitted to the atmosphere. For the propulsion of the AOS 71 motor glider, two types of propulsion were planned as development versions. The first analysed propulsion is based on a combustion engine, but of the Wankel type (LCR 814 engine with the power of 55 kW). The second designed propulsion is an hybrid based on a LCR 407 combustion engine with a power of 28 kW, which is connected in series with an electric generator propelling the engine (Emrax 228 engine), total power of the propulsion is 55 kW. The comparison of emissions of harmful compounds emitted to the atmosphere generated by the combustion and hybrid power unit intended for assembly in the AOS 71 motor glider, assuming various loads and methods of hybrid propulsion control, was made. The tests were conducted in laboratory conditions. Several different programs were designed to simulate different energy management methods in a hybrid system, depending on the predicted mission and load of the motor glider. On the basis of laboratory tests, exhaust emission was determined from both propulsions as a function of rotational speed and load. Then, based on the assumed flight trajectory and collected test data, the emission for both propulsions variants was determined. The values of emission parameters were compared and the results were presented in diagrams and discussed in the conclusions.
EN
Analysis of the possibility of using an engine with a rotating piston as the propulsion of an electric generator in application to a motor glider propulsion The paper presents an analysis of the possibilities of application of a rotating piston engine (Wankel type) as a propulsion for an electric generator in the motor glider propulsion system. This generator would be a part of the propulsion system of a hybrid motor glider using the AOS 71 motor glider airframe. In the research, the rotational characteristics of the LCR 407ti engine were determined experimentally. Driving torque run, power and fuel consumption were determined as a function of engine speed. The obtained results are presented in diagrams. The conceptual diagram of the hybrid drive is presented. The current generator was selected and the effectiveness of the generator and the entire propulsion were assessed from the motor glider's performance point of view. On the basis of the conducted research, conclusions were drawn and there were indicated the objectives and directions of further research on hybrid propulsion with specific aerodynamic and mass limitations of the aircraft.
PL
Pomiary emisji związków szkodliwych spalin podczas testów na hamowni podwoziowej są jednymi z najistotniejszych i najbardziej skomplikowanych badań, jakim są poddawane pojazdy napędzane silnikami spalinowymi. Podczas pomiarów emisji spalin należy zwracać baczną uwagę na wiele czynników, wpływających na prawidłowość otrzymywanych wyników. W artykule omówiony został wpływ regulacji hamowni podwoziowej wykorzystywanej do wykonywania pomiarów emisji związków szkodliwych spalin oraz zużycia paliwa.
EN
Exhaust emission measurements on the chassis dynamometer are one of the most important and most complex tests which are performed on vehicles powered by combustion engines. Many factors must be under control during exhaust emission measurements, which have an influence on correctness of the obtained results. In this paper, the impact of the chassis dynamometer regulation on the exhaust emission results is analysed.
PL
Przedmiotem niniejszego artykułu jest analiza drogowej emisji liczby oraz masy cząstek stałych w rzeczywistych warunkach eksploatacji z pojazdu hybrydowego. Co więcej, analizie poddano również warunki pracy badanego pojazdu oraz silnika. W tym celu wykonane zostały badania emisji cząstek stałych i parametrów eksploatacyjnych z lekkiego pojazdu samochodowego z napędem hybrydowym, wyposażonego w 104 kW silnik o objętości skokowej 1,58 dm3. Badania przeprowadzono w rzeczywistych warunkach ruchu, przestrzegając procedury RDE (Real Driving Emission). Test wykonano na obszarze aglomeracji poznańskiej, trasa obejmowała drogi o różnych dopuszczalnych prędkościach. Do badań wykorzystano mobilną aparaturę, należącą do grupy PEMS (Portable Emissions Measurement System), w skład której wchodziły takie urządzenia jak: SEMTECH DS., AVL MSS (Micro Soot Sensor) oraz EEPS 3090 (Engine Exhaust Particle Sizer). Uzyskane wyniki zostały odniesione do wartości dopuszczalnych emisji zgodnie ze standardem EURO 6.
EN
The subject of this article is the analysis of the particle number and mass road emission from a hybrid vehicle in real operating conditions. Additionally, the operating conditions of the tested vehicle and engine were also analyzed. To this end, particulate emissions and performance tests were carried out from a light hybrid vehicle, equipped with a 77 kW engine with a displacement of 1.58 dm3. The tests were conducted in real traffic conditions, following the standard RDE (Real Driving Emission) procedure. The test was performed within the Poznań agglomeration, the route included roads with different maximum speed limits. The research involved the use of mobile measuring equipment, belonging to the PEMS (Portable Emissions Measurement System) group, which included equipment such as: SEMTECH DS, AVL MSS (Micro Soot Sensor) and EEPS 3090 (Engine Exhaust Particle Sizer). The results obtained have been referred to the vehicle exhaust emission limit values in accordance with the Euro 6 norm.
PL
W artykule przedstawiono wyniki symulacji przepływu gazów wylotowych przez trzy konfiguracje ceramicznego nośnika umieszczonego w układzie wylotowym silnika. Nośniki różniły się parametrami gęstości cel na całej długości filtra. Przebadano filtr o stałym parametrze CPSI (ang. Cell per Square Inch), filtr o dwóch różnych gęstościach cel oraz nośnik potrójny. Dla każdego z elementów filtra wprowadzone zostały warunki brzegowe, które określają charakter przepływu oraz definiują rodzaj powierzchni danego elementu. Określony został także skład gazów wylotowych, których przepływ jest symulowany. Warunki początkowe symulacji zawierają dane dotyczące ciśnienia, temperatury oraz prędkości przepływu. Do przeprowadzenia symulacji wykorzystano oprogramowanie AVL Fire Aftertreatment. Program stanowi wiodące narzędzie do symulacji CFD w dziedzinie silników spalinowych.
EN
The article presents the results of exhaust gas flow simulation by three configurations of a ceramic support placed in the engine exhaust system. The carriers differed in the cell density parameters along the entire length of the filter. A filter with a fixed CPSI (Cell per Square Inch) parameter, a filter with two different cell densities and a triple support were tested. For each element of the filter, boundary conditions have been introduced, which define the nature of the flow and define the type of surface of a given element. The composition of the exhaust gases whose flow is simulated was also determined. The initial conditions of the simulation include data on pressure, temperature and velocity. AVL Fire Aftertreatment was used to carry out the simulation. The program is a leading tool for CFD simulation in the field of internal combustion engines.
first rewind previous Strona / 19 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.