Condensation particle counters (CPCs) use light scattering to count particles after they have grown to micron size in a supersaturated environment. In single counting mode each particle is counted depending on whether the scattered light exceeds a threshold value or not. In photometric mode the total scattered light is converted in particle number concentration. While for laboratory grade particle number systems, CPCs are allowed to operate only in single counting mode, there is no such requirements for portable emissions measurements systems (PEMS) for real-driving emissions (RDE) testing or for instruments for periodic technical inspection (PTI) of vehicles. In this study two CPCs of the same model were assessed in single counting and photometric modes with silver and graphite particles with sizes ranging from 10 nm to 100 nm. The results showed that the concentration was measured accurately enough for particles in the 25 nm to 50 nm size range, but was underestimated and overestimated for smaller and larger particles, respectively. The key message is that the photometric mode should be avoided or calibrated in function of concentration and particle size.
The following article presents the method of verification of EURO III standard in real conditions for special vehicles. The test object qualified as a special vehicle was tested in road conditions along a defined route, and then the obtained measurement results were compared to the exhaust emission standard (EURO III) applicable for this vehicle. A method of comparing the emission factors in road conditions with the indicators obtained on the engine dynamometer was proposed. An AVL mobile exhaust gas analyzers PEMS dedicated for RDE road tests were used in the research.
The basic problem in terms of measuring exhaust emissions is the approval tests of traction vehicles, which are carried out on engine dynamometers. Therefore, it is impossible to obtain reliable results concerning their actual impact on the natural environment. It is therefore advisable to carry out the tests in real operation conditions, as is the case for road vehicles for which RDE (Real Driving Emissions) tests are carried out. The latest Stage V emission standards push for the introduction of this type of test, but no limit values for toxic exhaust gases have been established and no test guidelines have been defined for assessing actual emissions. This article describes the issues related to the legislative guidelines for non-road vehicles in force in Europe, as well as the measurement tools used, such as mobile equipment for measuring emissions of PEMS (Portable Emissions Measurement Systems) and newly developed emission gates. Additionally, the paper presents examples of locomotive exhaust emission tests in real operating conditions. The aim of the measurements was to assess the emission of toxic compounds against the relevant standards. The subject of the research was a diesel locomotive type T448.P equipped with a modernized internal combustion engine.
The share of road transport accounts for more than 85% of the total structure of freight transportation. In this process, mainly motor vehicles are used to carry out the freight work. In addition to them, forklifts are also used, whose task is to load and unload goods. These vehicles are categorized as NRMM (Non-Road Mobile Machinery). Forklift trucks have internal combustion or electric drive. The paper presents an analysis of the emission of pollutants and fuel consumption from forklift trucks equipped with diesel and LPG power. The study uses the author's test taking into account the raising/lowering of a pallet, a loaded and unloaded run. The measurements were made in the warehouse and outside the warehouse using the Portable Emission Measurement System (PEMS) equipment. The aim was to show the influence of loading conditions on the emission of pollutants and fuel consumption.
Testing of real driving emissions (RDE) with portable emission measuring system (PEMS) in an appropriate road circuit became an obligatory element of new type approval of passenger cars since September 2017. In several projects the Laboratory for Exhaust Emissions Control (AFHB) of the Berne University of Applied Sciences (BFH) performed comparisons on passenger cars with different PEMS’s on chassis dynamometer and on road, considering the quality and the correlations of results. Particle number measuring systems (PN PEMS) were also included in the tests. The present paper informs about influences of E85 on RDE on two flex-fuel-vehicles, discusses some aspects of different ways of evaluation with different programs, shows comparison of different types of PN PEMS and represents the effects of simulation of slope on the chassis dynamometer.
The solid particle number method was introduced in the European Union (EU) light-duty legislation for diesel vehicles to ensure the installation of the best-available technology for particles (i.e., wall-flow diesel particulate filters) without the uncertainties of the volatile nucleation mode and without the need of large investment for purchasing the equipment. Later it was extended to gasoline vehicles with direct injection engines, heavy-duty engines (both compression ignition and positive ignitions) and non-road mobile machinery engines. Real Driving Emissions (RDE) testing on the road with Portable Emissions Measurement Systems (PEMS) for particle number (and NOx) during type approval and in-service conformity testing was recently (in 2017) introduced for light-duty vehicles, and is under discussion for heavy-duty vehicles in-service conformity testing. This paper will summarize the existing legislation regarding solid particle number and discuss the on-going activities at EU level. The main focus at the moment is on improving the calibration procedures, and extending the lower detection size below 23 nm with interlaboratory exercises. In parallel, discussions are on-going to introduce testing at low ambient temperature, regeneration emissions in the light-duty regulation, a particle limit for other technologies such as gasoline port-fuel injection vehicles, and the feasibility of particle measurements to L-category vehicles (mopeds, motorcycles, tricycles and minicars). A short overview of periodical technical inspection investigations and the situation regarding non-exhaust traffic related sources with special focus on brakes and tyres will be described.
The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO2 emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NOx. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm3 urban passenger car with a SI engine and a start-stop system, a 2.5 dm3 off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm3. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO2 emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.
At the beginning of the twenty-first century, one of the major challenges of humanity was to reduce the negative effects of civilization development. Besides the engines used in road vehicles there is a large group of engines for non-road applications. This group includes motor propelled vehicles not used on the road NRMM (Non-Road Mobile Machinery). Engines of these vehicles, among all of the non-road applications, are characterized by very specific working conditions that do not allow for them to be qualified for propulsion engines. The main problem with these vehicles is the particulate matter and nitrogen oxides emission. Rail vehicles operating conditions these requirements take by the similar way, as having a wide range of rolling stock markedly alters the environmental impact of these vehicles. Thus it becomes necessary to consider the issue of the method of evaluation of engine emissions in rail vehicles in terms of their actual operating conditions. Thus, efforts to assess the actual level of emissivity for rail vehicles and attempts to improve it are necessary and justified.
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