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The modern solution of two-stage combustion, namely the Turbulent Jet Ignition, enables the combustion of ultra-lean mixtures. Thanks to this solution, it became possible to reduce fuel consumption and, at the same time, to increase the combustion process indicators (including the overall combustion system efficiency). The article presents the results of numerical tests of a heavy-duty engine equipped with the TJI system running on hydrogen fuel. The operating conditions of the Heavy-Duty engine at n = 1500 rpm and IMEP = 10 bar with a prechamber with 7 holes were analyzed. The research was conducted with the use of lean mixtures (global lambda ca. 2 or more). The AVL FIRE software was used to perform the analysis of different fuel doses delivered to the main chamber, with a constant global excess air coefficient value. Increasing the proportion of hydrogen in the pre-chamber resulted in its reduction in the main chamber.

Exhaust gas aftertreatment systems can, under certain conditions, create undesired chemical species as a result of their elimination reactions. A prime example of this is ammonia (NH3), which is not formed in the combustion reaction, but which can be formed within a three-way catalyst (TWC) when physicochemical conditions permit. The elimination of NOx in the TWC thus sometimes comes at the cost of significant emissions of NH3. Ammonia is a pollutant and a reactive nitrogen compound (RNC) and NH3 emissions should be analyzed in this context, alongside other RNC species. Examination of the literature on the subject published over the past two decades shows that ammonia, a species which is currently not subject to systematic emissions requirements for road vehicles in any market, is often identified as forming the majority of the RNC emissions under a range of operating conditions.

Hybrid powertrains are replacing conventional combustion drives at an accelerating rate, while offering a reduction in fuel consumption and toxic exhaust emissions. The large share of hybrid solutions in engine vehicles has been observed for the compact class and in SUVs. The Authors of this study proposed an energy flow assessment in the hybrid powertrain system of an SUV in various driving conditions: urban, extra-urban and motorway. The tests were performed in accordance with the stipulations of the RDC test conditions and its requirements. The tests were carried out on a Toyota RAV4 HEV equipped with a 2.5 dm3 engine in a hybrid drive system along with Li-Ion batteries, which had an energy capacity of 1.11 kWh (4.3 Ah). The research was carried out on an urban route in Poznan as well as in its vicinity using three drive modes of the drive system: Eco, Normal and Sport.

This paper discusses the legislative situation regarding type approval of plug-in hybrid vehicles (also known as off-vehicle charging hybrid-electric vehicles, OVC-HEV) in the range of exhaust emissions and fuel consumption. A range of tests were conducted on two Euro 6d-complaint OVC-HEVs to quantify emissions. Procedures were based on EU legislative requirements. For laboratory (chassis dyno) testing, two different test cycles and three different ambient temperatures were used for testing. Furthermore, in some cases additional measurements were performed, including measurement of emissions of particulate matter and continuous analysis of regulated and unregulated pollutants in undiluted exhaust. Consumption of electrical energy was also monitored. On-road testing was conducted on the test vehicle tested on the chassis dyno in the tests mentioned above, as well as on a second OVC-HEV test vehicle.

The paper concerns the analysis of the combustion and exhaust emission phenomena in a direct gasoline dual injection system of a SI engine for various symmetrical injector placement parameters in the combustion chamber. Achieving a good combustion process is shaped by the direct fuel injection process, whose parameters vary. The novel direct injection system, which deploys two direct injectors mounted symmetrically, was subjected to this simulative research. This article focuses on the aspect of spatial and angular position of injectors in order to perform injection and achieve fuel combustion. The injector's pseudo-optimal location has been presented along with several changed positions (3 values of injector inset: 0, 1 and 2 mm, 3 values of injector distance from the cylinder axis: 16, 17, 18 mm and 3 values of angle between injector and the cylinder axis: 42.5, 45 and 47.5 degrees - 27 combinations altogether).

The benefits associated with the use of oxygen-containing diesel fuels in passenger cars are quite well described in the literature. This work describes the results of an 18-meter EEV city bus fueled with diesel fuel with the addition of 10% v/v of triethylene glycol dimethyl ether. This compound was chosen because it was effective in reducing exhaust emissions from light duty diesel vehicles. Emission tests (CO, HC, NOx and PM) of the city bus were performed over SORT (Standardized On-Road Tests) cycles using portable exhaust gas analyzers - PEMS. Significant differences in the emission of exhaust components were observed in individual SORT cycles. The level of road emissions reduced as the traffic smoothness increased, i.e. from the SORT 1 to SORT 3 cycle. The largest reduction in bus emissions associated with the use of the oxygenated additive (triethylene glycol dimethyl ether) applies to carbon monoxide and ranges from 50% for the SORT 3 cycle up to 90% for the SORT 1.

The article is an investigation into the exhaust emission impact of operating a shunting locomotive SM42 and a track diagnostics machine UPS-80-001. The comparison of the two vehicles makes it possible to estimate the overall environmental costs of two different types of rail vehicles operating at their typical work parameters. This was done using selected exhaust emission indicators. It is used to indicate the need for further improvement in vehicle ecology such as hybrid or electric systems. Other solutions are investigated as forms of mitigating the ecological impact of operating such vehicles in or near human population centers.

Particles are one of the pollutants that affect air quality. The assessment of air pollution degree is conducted, among others, on the basis of parameters regarding the mass concentration of particles (PM2.5 and PM10). The growing awareness of the processes accompanying particles emissions is causing a growing interest in their other parameters such as number and diameter. Particles dimensions are important in determining their impact on human health. The most dangerous are particles of the smallest size; characteristic for internal combustion engines, mainly jet engines. The assessment of individual means of transport from the point of view of their ecological aspects is carried out in relation to fuel consumption, while in the case of particles; the analysis must be extended by their individual parameters. The article presents a comprehensive analysis of particles emissions from a jet engine during stationary tests.

The article describes issues related to the impact of transport means on the environment. These issues are currently very popular due to the increasing public awareness of the negative environmental and health effects associated with air pollution. The authors estimated specific emissions in passenger-kilometers, considering a domestic travel by air and road transport. The analyzed route is located between the Polish cities: Gdansk and Cracow. The selected route is long by domestic travel standards, but in that travel distance, the road transport is still competitive to the air transport. Selected means of transport belong to popular representatives in their classes. As a road vehicle, the authors selected a modern passenger car powered by a spark ignition engine, meeting the Euro 6 emission standard. Among the passenger aircrafts, an object which belongs small jet aircrafts, propelled with Rolls-Royce Tay 611C jet engines was selected.

Hydrogen Fuel-Cell (HFC) technology is popular in Asia (mainly Japan), the US (chiefly California) and Europe. HFC is mostly used in passenger cars and urban buses. HFC technology is also being introduced to railway transport. Hydrogen-powered trains are an attractive alternative to diesel trains, in particular on nonelectrified railways - where roughly 70% of the world’s 200 000 locomotives operate today - and in the markets of Europe and the US (together about 55 000 diesel locomotives today). Besides avoiding carbon emissions, hydrogen trains reduce noise and eliminate local emissions of NOX and particulates. Since they use significant amounts of hydrogen, the required infrastructure is limited and can be immediately utilised. Hydrogen-powered trains are already being introduced for light-rail vehicles and regional railways - such as the trams produced by the China South Rail Corporation.

There is a growing appreciation for using buses powered by alternative fuels in urban transport. Considered as such are city bus with engines fuelled with LNG and hybrid bus. This article, as shown above, provides a comparison of road exhaust emissions from three city buses: one with a CI engine fuelled with diesel fuel, and the other with a SI engine fuelled with LNG and Hybrid bus. Both vehicles (CI and LNG) conformed to Euro VI emission standard (hybrid bus EEV), and the tests were carried out in real traffic conditions. Equivocal opinions about differences in emissions from those types of buses, among others - CO2 and NOx emissions, were the underlying cause of the tests. The comparative study was carried out along the same urban routes during bus trips over the following days in similar traffic conditions. Exhaust road emission was determined based on the vehicle's curb weight and route length, and operating fuel consumption.

The share of hybrid and electric powertrains in the market increases continuously. In local driving conditions, electric vehicles are zero-emission, yet their regular use requires an infrastructure allowing the recharging of high-voltage batteries. Hybrid vehicles also allow the use of the electric drive; however, when the high-voltage battery is low, a combustion engine is used to recharge it. Hybrid powertrains do not require any changes in the infrastructure, nor do they force any changes in the driver's habits. The use of a hybrid vehicle may, however, reduce the operating time of the combustion engine, thus contributing to the reduction of fuel consumption. This reduction of fuel consumption results from a specifically selected energy flow strategy in hybrid systems. This strategy was the focus of the research performed to identify the energy flow conditions in a hybrid drive system under driving conditions corresponding to the RDE test.

Non-Road machines constitutes a large group of machines designed for various tasks and mainly using CI engines for propulsion. This category includes vehicles with drive systems of a maximum capacity of several kilowatts as well as with drives with a capacity of up to thousands of kilowatts depending on the purpose of the machine. Within this group, mobile machines referred to as NRMM (Non-Road Mobile Machinery) stand out. Numerous studies of scientific institutions in Europe and around the world have proven the differences between the exhaust emissions tested in type approval tests and the actual emissions in this group of vehicles. They result from differences in operating points (crankshaft speed and load) of engines during their operation. A big problem is also their considerable age and degree of wear. Approval standards themselves are less stringent than those of heavy-duty vehicles (HDVs), although the engines have similar design and performance.

European Union RDE (real driving emissions) legislation requires that new vehicles be subjected to emissions tests on public roads. Performing emissions testing outside a laboratory setting immediately raises the question of the impact of ambient conditions - especially temperature - on the results. In the spirit of RDE legislation, a wide range of ambient temperatures are permissible, with mathematical moderation (correction) of the results only permissible for ambient temperatures <0°C and >+30°C. Within the standard range of temperatures (0°C to +30°C), no correction for temperature is applied to emissions results and the applicable emissions limits have to be met. Given the well-known link between the thermal state of an engine and its emissions following cold start, ambient temperature can be of great importance in determining whether a vehicle meets emissions requirements during an RDE test.

This paper discusses the importance of the inclusion of emissions from the cold start event during legislative on-road tests on passenger cars (RDE - real driving emissions tests conducted under real-world driving conditions, as defined by EU legislation). Results from a recently-registered gasoline-powered vehicle are presented, with the main focus on the comparison of exhaust emission results: excluding/including the cold start during the initial phase of the RDE test. Cold start is the most challenging aspect of emissions control for vehicles with spark ignition engines and the inclusion of the cold start event in RDE test procedure has wide-ranging implications both for the testing process and compliance with RDE legislation via optimisation of aftertreatment systems and the engine calibration. In addition to some theoretical arguments, the results of an RDE-compliant test performed using the aforementioned procedures are presented.

In this study, two vehicles were tested under real driving conditions with gaseous exhaust emissions measured using a portable emissions measurement system (PEMS). One of the vehicles featured a hybrid powertrain with a spark ignition internal combustion engine, while the other vehicle featured a non-hybrid (conventional) spark ignition internal combustion engine. Aside from differences in the powertrain, the two test vehicles were of very similar size, weight and aerodynamic profile, meaning that the power demand for a given driving trace was very similar for both vehicles. The test route covered urban conditions (but did include driving on a road with speed limit 90 km/h). The approximate test route distance was 12 km and the average speed was very close to 40 km/h.

This paper presents a study of passenger cars in terms of emissions measurements in tests conducted under real driving conditions (RDE - Real Driving Emissions) by means of PEMS (Portable Emission Measurement System) equipment. A special feature of the RDE tests presented in this paper is that they were performed under Polish conditions and the specified parameters may differ from those in most other European Union countries. Emission correction coefficients have been defined, based on the test results, equal to the increase (or decrease) of driving emissions during the laboratory (‘chassis dyno’) test or during normal usage in relation to the EU emission standards (emission class) of the vehicle.

The paper describes the measurement of PM emission from an excavator engine under actual operating conditions. The exploration of the relations between the engine operating parameters and its emissions requires measurements under actual conditions of engine operation. The specificity of the emission measurements, PM in particular, requires technologically advanced measuring devices. The situation gets even more complicated when, beside the PM mass. The particle size distribution and number (PN) also need to be measured. An important technical issue is the difficulty in fitting the measurement equipment in/on the vehicle in operation (e.g. excavator), which is why the presented investigations were carried out in a laboratory under simulated operation. The laboratory technicians applied load to the engines through the excavator hydraulic system.

The paper presents the results of tests on a combustion engine of an armored modular vehicle 8x8 Rosomak under combat simulating conditions. For the measurements of the toxic compounds a portable SEMTECH DS analyzer by SENSORS was used. The analyzer allowed a measurement of toxic compounds at the same time measuring the mass flow rate of the exhaust gases. The analysis of the PM emission was performed based on the measurement of the size of the particulate matter (analyzer 3090 EEPS - Engine Exhaust Particle Sizer™ Spectrometer - by TSI Incorporated) and counting of the particles (analyzer Particle Counter by AVL). The measurements of CO, HC, NOx, PM and fuel consumption were performed under the conditions of combat simulation and in the overboost mode. Based on the obtained results, an analysis of the engine and vehicle operation was performed and the on-road and unit exhaust emissions as well as on-road and unit fuel consumption were compared.

The tests related to the exhaust emissions from non-road vehicles are currently performed on a chassis dynamometer under the name of NRSC (ISO 8178) and NRTC. In light of the growing requirements related to the environment protection in transport the authors recommend determining the exhaust emissions through real vehicle operating conditions. The tests carried out under real operating conditions could be used for the process of optimization of future power trains of regular road vehicles and non-road vehicles. What is more, these tests should be taken into account in the works on the changes of the legislation related to the emission limits from combustion engines. The paper presents the results of the tests on the exhaust emissions from an agricultural harvester engine and a tractor engine in real operating conditions. The harvester operation during the test consisted in crops collection from the field and the tractor operation during the test consisted in plowing.