Digital vibroacoustic signal processing for combustions in heavy-duty diesel engine for operational and environmental machine efficiency

The paper concerns the assessment of a combustion process correctness in direct injection compression-ignition engine of a HDV vehicle. The method of such diagnoses is based on the vibration acceleration signal and its digital processing. Identification of a combustion process runs and detection of some failures taking place in the combustion chamber during engine working cycles are important in the point of view of environmental and operational engines characteristics. That is why the authors considered this scientific problem, trying to show the possibility of the precise diagnosis of combustion process regarding with the requirements of OBD regulations. The method of misfire identification for a compression-ignition engine, based on results of parameterizations of a time-frequency a(t,f) map of an engine vibration signal taken from engine heads, was used in the diagnostic process. Parameterization of a(t,f) map gives measures covariable with misfire in a cylinder of an internal combustion engine and obtained point measures can be used as diagnostic parameters for combustion process control and its diagnostics. Reliability of a method for combustion process assessment was checked for research conducted in stationary and real engine operation conditions

Rapeseed Oil Methyl Esters (RME) as Fuel for Urban Transport

The use of biofuels is justified by the common agricultural policy decisions, by the need to improve environment protection and by the search of alternative energy sources. In such a context, methyl esters of vegetable oils, known as biodiesel and ethyl alcohol are receiving increasing attention as alternative fuels for automotive engines. The main advantages of biodiesel and ethyl alcohol are that these fuels are nontoxic, biodegradable, and renewable with the potential to reduce engine exhaust emissions, especially with regard to greenhouse gases emission. The fact that these biofuels are available in larger and larger quantities is of great importance as well. Currently, in the European market the most important biofuel is FAME (Fatty Acid Methyl Esters) manufactured mainly as Rapeseed Methyl Esters (RME). It is forecasted that the scale of production and consumption of this fuel will continue increasing as a result of the growing demand for diesel fuels and a levelled demand for spark-ignition engine fuels. Currently, FAME is added to regular diesel fuels in the amount of up to 7%. Besides, its consumption in a pure form grows as well. This chapter presents ecological properties of RME in relation to conventional diesel fuel. The aim of the research was to determine the potential of RME in reducing exhaust emissions (CO, HC, NOx and PM) from diesel engines operated in buses. The tests were carried out in real operating conditions of a city bus meeting EEV emissions standard. Comparative analysis made it possible to assess the environmental performance of buses depending on the type of fuel used. The obtained results indicate a slightly lower emission of CO, HC and PM when the vehicle was fuelled with RME but at the same time its application results in a slight increase in the emission of NOx. It seems that similar level of exhaust emissions recorded regardless of fuel type results from an advanced exhaust gas aftertreatment system (SCR + DPF) which was applied in the test vehicle

Measurement of Exhaust Emissions under Actual Operating Conditions with the Use of PEMS: Review of Selected Vehicles

This paper is a synthetic approach to real driving (RDE) from selected vehicles: light-duty vehicle (LDV), heavy-duty vehicle (HDV). The tests were performed with the portable emission measurement system (PEMS) equipment under actual traffic conditions. The paper discusses problems of measurement methodology and emission of CO, HC, NOx, and PM. The performed investigation confirms that the main problem is the emission of NOx and PM, which usually is higher than the emission level. The obtained results show that the RDE method is very complex, but is the only way to provide invaluable information on the actual on-road exhaust emissions, not obtainable under laboratory conditions. In recent years, methods of exhaust emission testing under actual operating conditions have been developing rapidly. New technologies for extra low engine emissions pose a new question: does emission testing in a standard laboratory reflects real life emissions of a vehicle in use? In order to answer this question, it is necessary to measure the vehicle in-use emissions. Today, we know that the engine operating conditions (engine load and speed) in laboratory tests are not compliant with the conditions of actual operation. That is why the results of such tests are so desirable

Environmental Aspects of the Use of CNG in Public Urban Transport

This chapter concerns the problem of assessing the exhaust emission from the engines of city transport buses fuelled by CNG. It presents a comparative analysis of toxic exhaust emissions of CO, HC, NOx and PM, from urban buses powered by diesel and CNG. The measurements were carried out over the SORT standardised cycles as well as during a real drive condition on a city bus route. The research revealed that CNG bus generates significantly lower NOx emission, whereas its CO and HC emissions are higher. Taking into account low PM emissions, CNG buses should be regarded as eco-friendly means of public transport

Research of Exhaust Emissions from a Harvester Diesel Engine with the Use of Portable Emission Measurement System

This paper presents the test results of exhaust emissions from the engine of a wheeled harvester. On the basis of the present analysis, the ranges of most frequently used engine loads and speeds were determined. The obtained time density characteristics (distribution of engine speeds and loads in time) of the engines were referred to the measuring points of the exhaust emission homologation test. During the measurement of the exhaust emissions, the machine was in the forest engaged in tree cutting. Exhaust emission tests from non-road vehicle engines are currently performed on engine test beds in the NRSC and NRTC tests. The present methodology is a new solution that could be used in the future as a basis for the development of harvesting technology aimed at reducing exhaust emissions from engines. During the tests, the authors also measured the amount of timber harvested during the felling process in order to be able to relate the emission results to the amount of the generated product. Harvesters are more and more often used in forest operations but they still have to compete with handheld (gasoline powered) chainsaws and that is why in this paper the authors included a comparison of the exhaust emissions from a chainsaw with the emissions from the engine of a harvester. The authors used a portable analyzers (SEMTECH DS and LAM manufactured by SENSORS) for the measurement of the exhaust emissions. The said analyzer can measure the concentrations of exhaust gas components in an on-line mode, while the engine is running under field conditions

Determination of exhaust emission characteristics in the RDE test using the Monte Carlo method

The article presents a method of determining the characteristics of exhaust emissions and fuel mass consumption in real driving conditions based on a single test using the Monte Carlo method. The exhaust emission characteristics used are the relations between the emissions and the average vehicle speed, and the characteristic of the fuel mass consumption is the dependence of the fuel mass consumption at the average vehicle speed. The results of empirical research of a passenger car with a spark-ignition engine in the RDE test were used. The use of the Monte Carlo method made it possible to select the initial and final moments of averaging the process values, thanks to which it was possible to determine the discrete values of the characteristics for various values of average vehicle speeds. The determined discrete characteristics of the particulate mass and number emissions and fuel mass consumption relative to the average vehicle speed were approximated by polynomial functions of the second and third degree. The determined discrete characteristics, presented as sets of points, were characterized by a relatively small dis-persion in relation to their polynomial approximations. The average relative deviation of the points of discrete characteristics from the value of the polynomial was in most cases small less than 4%, only in the case of the number of particles emitted deviated from this, as the average relative deviation of the measured points from the determined polynomial was nearly 14%. Combined with the results of RDE empirical studies, the Monte Carlo method proved to be an effective method for determining the characteristics of exhaust emissions, measured in real vehicle operating conditions. The main advantage of the proposed method was a significant reduction in the actual workload necessary to carry out the empirical research where it became possible to determine the charac-teristics in a large range of vehicle average speed values with just one drive test. Using standard methods of meas-uring this type of data, it would be necessary to conduct multiple tests, driving at different average vehicle speeds

Specific emissions analysis for a combustion engine in dynamometer operation in relation to the thermal state of the exhaust gas aftertreatment systems in a modified NRSC test

Exhaust gas aftertreatment systems have been present in motor vehicles for decades and have contributed to reducing their impact on the environment and people. Most of them for oxidation or reduction of harmful emissions of particulates and fumes require a certain temperature to be reached that changes with the exhaust temperature, i.e. the points of engine operation. The article describes the effect of oxidation reactor and particulate filter temperatures on specific emissions of gaseous compounds and particulate matter during the modified NRSC engine test. Before the first measurement cycle, the engine was idling, before the second measurement cycle, the exhaust system was heated with exhaust gases at full engine load until passive regeneration of the particle filter occurred (noticeable decrease in instantaneous particle concentration)

The growth in the use of methane fuel for fuelling urban buses

Urban transport vehicles have a large share in city traffic. This results in higher emission of hazardous substances and poses direct threat for human life by causing smog. Research and implementation works are underway to prevent this situation. In city transport attention is given to electric and hybrid vehicles, as well as gas vehicles that are used. The last group, i.e. city buses with engines fuelled with methane fuels have positive impact on decreasing emission of certain hazardous substances. This article addresses internal tests and their results that confirm the rationality underlying the use of these fuels in city transport buses

Tests and simulations referring to application the vibroacoustic methods for diagnosing the misfiring in the engines with the self-ignition of the diesel locomotives

Niniejszy artykuł dotyczy możliwości zastosowania metody oceny procesu spalania i jego braku w silnikach spalinowych pojazdów szynowych, bazującej na wykorzystaniu parametrów sygnału drganiowego. Zamieszczono w nim wyniki badań silnika spalinowego lokomotywy w warunkach jej eksploatacji. Wykazano możliwość zastosowania estymat sygnału drganiowego do oceny braku spalania w silniku spalinowym oraz dużą wiarygodność diagnostyki procesu spalania za pomocą powyższej metodyThe present article refers to the possibility of application the assessment method of the combustion process and its lack in the diesel engines of the rail vehicles, basing on using the parameters of the vibration signal. The results of tests of the diesel engine of the locomotive in the conditions of its operation are placed in it. It is shown the possibility of application the estimates of the vibration signal for assessment of the lack of combustion in the diesel engine and the big credibility of the diagnosis of the combustion process by means of the above mentioned method