Heavy-duty Vehicle Emissions Research Articles

Assessment of waste heat recovery for heavy-duty vehicles during on-road operation

Waste Heat Recovery (WHR) by means of an Organic Rankine Cycle is a technology often proposed to reduce the fuel consumption and CO2 emissions of heavy-duty vehicles. A Class 5 Heavy Lorry (tractor) with a WHR system was measured over various driving cycles on the chassis dyno and under realistic conditions on the road, performing each test-cycle with WHR enabled and disabled. The use of WHR lead to reductions in fuel consumption of 3.1% over the World Harmonized Vehicle Cycle, 2.5% over the Regional Delivery Cycle (RDC) and 1.9% over the on-road trips. The WHR system was able to produce more power output during the RDC on the chassis dyno compared to the on-road trips, as more exhaust energy was available during the RDC, resulting in a more considerable reduction of the fuel consumption. No statistically significant reduction of the pollutant emissions was observed. On-road trips were simulated with the Vehicle Energy Consumption calculation Tool, (VECTO), and the fuel consumption was predicted with an error of less than 1.5% for the individual trips and less than 0.5% when averaged over the different repetitions. These findings demonstrate the capability of VECTO to accurately simulate vehicles with Waste Heat Recovery under realistic conditions on the road.

Analysis of fuel consumption and emission between C-WTVC and PEMS methods of heavy-duty vehicle

The chassis dynamometer and PEMS test implemented on a heavy-duty vehicle,through comparing the working condition, fuel consumption and emissions result,it showed that the engine working area in PEMS test occupy most of the working area under the engine performance curve from 1300r/min to 2500r/min at the medium load. In the C-WTVC cycle the engine usually worked below 1900r/min at medium and heavy load.Thus in PEMS test the fuel consumption and pollutant emissions are higher than them in C-WTVC test,the fuel consumption is 12.54L/100km which is 9.3% higher, the brake specific emission of NOx,PN,CO are 91.0%,38.7% ,78.9% higher respectively.The PEMS test is more practical and convenient for heavy-duty vehicle emission test while has a poor measurement repeatability under the influence of different road conditions.The C-WTVC test cycle has a good measurement repeatability for its fixed condition.

A detailed study on regeneration of SO2 poisoned exhaust gas after-treatment catalysts: In pursuance of high durability and low methane, NH3 and N2O emissions of heavy-duty vehicles

Utilization of natural gas fuels in heavy duty vehicles offers an effective solution to reduce global warming and improve urban air quality. However, there are problems related to catalyst durability and release of unburned methane (methane slip). Catalyst durability can be achieved through clever designs of both catalyst material and its regeneration process. In this paper, we studied extensively low temperature regeneration strategies of a commercial methane oxidation catalyst (MOC), a three-way catalyst (TWC) and a diesel oxidation catalyst (DOC) as well as two coupled catalysts; TWC-MOC and DOC-MOC. Methane and propane conversion along with NO2, NO, SO2, CO, N2O and NH3 formation were recorded and analyzed in a laboratory setup using a FTIR multigas analyzer. According to our findings, the MOC and the DOC can be regenerated under a broader range of O2 concentrations whereas the TWC requires a very low O2 concentration or anoxic conditions for efficient regeneration. The conversion increase ranged between 0 and 20 percentage points for methane and 0–45 percentage points for propane depending on the catalyst and regeneration technique. The coupled catalysts were highly effective in methane conversion and possessed higher tolerance against SO2 poisoning compared to single catalysts. The study further revealed that 10 ppm regulation limit of NH3 emission is plausible to exceed during the regeneration of a catalyst. By controlling the exhaust gas composition during the regeneration and length of the regeneration, the NH3 and N2O emissions can be minimized.

Analysis of the engine test cycles from China VI heavy duty vehicle standard and China automotive test cycle

This paper studied the engine test cycles including world harmonized steady cycle (WHSC), world harmonized transient cycle (WHTC) , china heavy-duty steady cycle (CHSC) and china heavy-duty transient cycle (CHTC) based on a diesel engine which meet the China VI heavy duty vehicle emission standard. The results show that regression analysis of speed, torque and power all meet the requirements of the China VI heavy duty vehicle standard. For this engine, NOx, PM and THC pollutants under CHSC are 134.5%, 29.6% and 94.4% higher than those under WHSC, respectively. PN emissions of CHSC is 65.6% lower than that of WHSC. NOx, PM and PN pollutants under CHTC are 62.9%, 96.4% and 64.3% higher than those under WHTC, respectively. The exhaust temperature of the first 350 seconds at CHTC is lower, which poses a greater challenge to the conversion efficiency of the after-treatment system at low speed and low load.

A Big Data Application for Low Emission Heavy Duty Vehicles

Abstract Recent advances in green and smart mobility aim to reduce congestion and foster greener, cheaper and with less delay transportation. The reduction of fuel consumption and CO2 emissions have worked on light-duty vehicles. However, the reduction of emissions and consumables without sacrificing on emission standards is an important challenge for heavy-duty vehicles. The paper introduces a big data system architecture that provides an on-demand route optimization service reducing NOx emissions of heavy-duty vehicles. The system utilizes the information provided by the navigation systems, big data analytics such as predictive traffic and weather conditions, road topography and road network and information about vehicle payload, vehicle configuration and transport mission to develop a strategy for the best route and the best velocity profile. The system was proven efficient during the performance evaluation phase, since the cumulative engine-out NOx has been decreased more than 10%.

On-Road Portable Emission Measurement Systems Test Data Analysis and Light-Duty Vehicle In-Use Emissions Development

<div>Portable emission measurement systems (PEMS) [<span>1</span>] are used by the US Environmental Protection Agency (EPA) to measure gaseous and particulate matter mass emissions from vehicles in normal, in-use, on-the-road, and “real-world” operations to support many of its programs. These programs include vehicle modeling, emissions compliance, regulatory development, emissions inventory development, and investigations of the effects of real, in-use driving conditions on NOx, CO<sub>2</sub>, and other regulated pollutants.</div> <div>This article discusses EPA’s analytical methodology for evaluating light-duty vehicle energy and EU Real Driving Emissions (RDE). A simple, data-driven model was developed and validated using measured PEMS emissions test data. The work also included application of the EU RDE procedures and comparison to the PEMS test methodologies and FTP and other chassis dynamometer test data used by EPA for characterizing in-use light- and heavy-duty vehicle emissions. This work was conducted as part of EPA’s participation in the development of UNECE Global Technical Regulations and also supports EPA mobile source emission inventory development. This article discusses the real-world emissions of light-duty vehicles with 12V Start-Stop technology and light-duty vehicles using both gasoline and diesel fuels.</div>

On-board monitoring (OBM) for heavy-duty vehicle emissions in China: Regulations, early-stage evaluation and policy recommendations

The latest China VI emission standard has introduced a remote monitoring rule for regulating in-use emissions of heavy-duty diesel vehicles (HDDVs). Real-time data regarding engine and aftertreatment operating conditions and tailpipe nitrogen oxides (NOx) concentrations are required to be collected through electronic control unit and on-board NOx sensors by vehicle original equipment manufacturers (OEMs), and then transmitted to environmental authorities. Beijing has developed a local standard that requires OEMs to design China VI-like on-board monitoring (OBM) systems for new China V HDDVs since September 2018. Additionally, Beijing has been a pioneer in retrofitting in-use China IV and China V HDDVs with OBM systems since 2017. This paper contains a timely technical and policy assessment for the state-of-the-art OBM programs in China with a focus on the recent progress in Beijing. Both OEM-performed and retrofitted OBM data were collected from a fleet of OBM-instrumented vehicles. First, our assessment shows high data integrity and quality of OEM-performed OBM systems. In contrast, a considerable fraction of HDDVs equipped with retrofitted OBM systems did not completely report NOx concentrations, intake mass air flow and other parameters. Next, eight OBM-instrumented HDDVs were tested on road by portable emissions measurement systems (PEMSs) to examine the reliability of sensor-based NOx concentrations. The majority (6 of 8) shows a good agreement between OBM and PEMS results with an average relative error of approximately −15%. Furthermore, calculation of NOx mass emissions, inter-trip variability, and alternative methods of enforcing in-use emissions management (e.g., to develop concentration metric-based emission limits) are discussed. This early-stage assessment suggests the OBM approach has the potential to play a central role in in-use emission inspections for HDDVs in China. The regulatory agency should focus more attention to the data integrity and the reliability of NOx sensors by developing effective verification processes.

Modelling of a thermoelectric generator for heavy-duty natural gas vehicles: Techno-economic approach and experimental investigation

Global CO2 emissions of heavy-duty vehicles are rising steadily and will continue to increase in the future without the implementation of measures such as technologies to reduce fuel consumption and emissions. In recent years, vehicles with natural gas-powered engines have increasingly been used as an economical and environmentally friendly alternative to diesel engines to reduce emissions. In addition to their lower emissions, these offer a high potential for waste heat recovery.A thermoelectric generator as a waste heat recovery system represents a cost-efficient technology for fuel and emission reduction. Integrated in the exhaust system, some of the otherwise lost heat can be converted to useful electrical energy. The advantages of thermoelectric generators compared to similar systems are low maintenance requirements and therefore a low cost-benefit ratio.This paper presents research on thermoelectric generator systems for heavy-duty natural gas vehicles on multiple levels. As a novelty, a holistic approach is applied, which includes interactions between all its components, all interactions with the overall vehicle system and the total cost of ownership. This approach is combined with a multiphysical numerical simulation model to obtain an economically suitable design. The solution of the simulation study is validated by an experimental investigation using a single channel system with commercially available thermoelectric modules. Approximately 70% of the simulated output power and the calculated efficiency could be measured.The proposed thermoelectric generator solution for heavy-duty natural gas vehicles achieves a peak power of 1507 W and a power density of up to 50 W kg−1. The results indicate a net fuel reduction of −0.54% (gross −1.04%). This is equivalent to a reduction of CO2 emissions of 4.9 (9.4) gCO2 km−1. The maximum system efficiency is simulative up to 4.2% (3.7% experimental). The overall system costs are estimated at 1811 EUR and thus represent a cost-benefit ratio of min. 1.2 EUR W−1. The results exceed the state of the art by more than 84%.The investigated commercially available thermoelectric modules with a power density of 1.1 W cm−2 are currently not application-oriented and are unable to fulfil the economic target of an amortization period of less than 3 years. New approaches are required and discussed. The new solution found with a power density of up to 3 W cm−2 and an efficiency of up to 9% indicates a high potential regarding the future cost-benefit ratio of the technology and will be adopted for further research and development activities.

Well-to-wheels total energy and GHG emissions of HCNG heavy-duty vehicles in China: Case of EEV qualified EURO 5 emissions scenario

Energy security and climate change are critical concerns in the present era. The booming of the vehicle population has worsened the environment and has caused severe air pollution problems, especially in urban areas. The utilization of hydrogen-enriched compressed natural gas in internal combustion engines shows abundant prospects for improved performance and reduced on-road emissions of greenhouse gases and air pollutants. This study aims to provide an insight to well-to-wheels environmental implications of the 20%HCNG fuel mixture in terms of total energy use, and greenhouse gas emissions per megajoules (MJ) of thermal energy output. The well-to-tank (WTT) impacts were evaluated using GREET 1 (2017). GREET 1 is a fuel cycle modeling tool developed by ‘Argonne national laboratory.’ GREET® is extensively used by researchers worldwide to analytically simulate energy use and emission output of various vehicle and fuel combinations. This study uses 12 prospective pathways of gaseous hydrogen production for analysis purposes. In the tank-to-wheels (TTW) phase, the 20%HCNG@EEV reduces the brake specific energy consumption (BSEC) by approximately 5%, and also decreases GHG emissions by 14% compared with 0%HCNG@EURO3. For simplicity, EURO5 is entitled as ‘EEV’ and has been excluded in most of the discussion, only highlighting ‘EEV,’ which abbreviates as ‘Enhanced Environmentally friendly Vehicles.’ For the entire well-to-wheels phase, this research work shows that all of the 20%HCNG@EEV pathways have lower total energy use and GHG emissions than 0%HCNG@EURO3 except the two pathways, such as grid electricity-to-hydrogen (without CO2 sequestration) and coal gasification-to-hydrogen (without CO2 sequestration). The WTW total energy and GHG emissions reduced by approximately 14% and 13%, respectively, with 20%HCNG@EEV based on the coke oven gas pathway compared with 0%HCNG@EURO3. It is essential to note that the use of cleaner feedstock for hydrogen, such as power-to-gas (P2G), biomass, coke oven gas (by-product), and natural gas shows tremendous prospects for realizing and practicing sustainable ‘hydrogen economy’ in China. Further technological advancement and reduction in total costs of HCNG utilization in powertrains will increase the number of HCNG vehicles decreasing the burden of air pollution, climate change, and energy crisis threats.

Green Traffic-Oriented Heavy-Duty Vehicle Emission Characteristics of China VI Based on Portable Emission Measurement Systems

With a continuous increase in vehicle ownership, vehicle emissions have become one of the main sources of air pollution in China. Serious air pollution is a great threat to human health and life. The China VI regulations, which adopt strict particulate matter (PM) and nitrogen oxide ( ${\mathrm {NO}}_{x}$ ) limitations, have been implemented. As one of the best technologies for measuring vehicle emissions, portable emission measurement systems (PEMSs) have gained attention. In this work, the characteristics of China VI heavy-duty vehicle emissions were investigated with a PEMS. The effects of road conditions on NO x , hydrocarbon (HC), carbon monoxide (CO), PM and particle number (PN) pollutants were analyzed based on distance-based emission factors. The results show that the gaseous pollutant levels of NO x , HC and CO for China VI vehicles are much lower than those for China V vehicles. The average distance-based emission factors of NO x CO and HC decreased by 88%, 98%, and 62.7%, respectively. Based on the power-based window method, the PEMS test results for NO x , HC and CO are 460 mg $\cdot $ (kWh)−1, 192 mg $\cdot $ (kWh)−1 and 37.5 mg $\cdot $ (kWh)−1, respectively. According to the PEMS tests, approximately 88%–95% of the particles are in the 10–100 nm class based on three typical operational modes, which represent approximately 0.08%–0.13% of the total particle mass. These heavy-duty vehicles can satisfy the requirements of the PEMS China VI standards. This study emphasizes the importance of obtaining real-world measurements of heavy-duty vehicles to improve the accuracy of emission factors in the development of emission inventories in China.

Regulated emission characteristics of in-use LNG and diesel semi-trailer towing vehicles under real driving conditions using PEMS

On-road driving emissions of six liquefied natural gas (LNG) and diesel semi-trailer towing vehicles (STTVs) which met China Emission Standard IV and V were tested using Portable Emission Measurement System (PEMS) in northern China. Emission characteristics of these vehicles under real driving conditions were analyzed and proved that on-road emissions of heavy-duty vehicles (HDVs) were underestimated in the past. There were large differences among LNG and diesel vehicles, which also existed between China V vehicles and China IV vehicles. Emission factors showed the highest level under real driving conditions, which probably be caused by frequent acceleration, deceleration, and start-stop. NOx emission factors ranged from 2.855 to 20.939 g/km based on distance-traveled and 6.719–90.557 g/kg based on fuel consumption during whole tests, which were much higher than previous researches on chassis dynamometer. It was inferred from tests that the fuel consumption rate of the test vehicles had a strong correlation with NOx emission, and the exhaust temperature also affected the efficiency of Selected Catalytic Reduction (SCR) after-treatment system, thus changing the NOx emission greatly. THC emission factors of LNG vehicles were 2.012–10.636 g/km, which were much higher than that of diesel vehicles (0.029–0.185 g/km). Unburned CH4 may be an important reason for this phenomenon. Further on-road emission tests, especially CH4 emission test should be carried out in subsequent research. In addition, the Particulate Number (PN) emission factors of diesel vehicles were at a very high level during whole tests, and Diesel Particulate Filter (DPF) should be installed to reduce PN emission.

Effect of Sampling Conditions on the Sub-23 nm Nonvolatile Particle Emissions Measurements of a Moped

The solid (or nonvolatile) particle number (SPN) emissions of light-duty and heavy-duty vehicles and engines are regulated in the European Union. The measurements are conducted from the tailpipe during on-road tests, but from the dilution tunnel in the laboratory under controlled conditions. Recently, dedicated laboratory studies for the evaluation of the measurement uncertainty at the two sampling locations found differences due to the formation of nonvolatile particles, i.e., particles that do not evaporate in the thermal pre-treatment part of the particle number systems. In order to investigate the origin of these particles, measurements at the tailpipe, the transfer tube, and the dilution tunnel were conducted with cold and hot dilution and instruments with different lower detection limits (4 nm, 10 nm, and 23 nm). The results showed that sub-23 nm nonvolatile particles could be detected in the dilution tunnel, but not at the tailpipe, due to growth of low volatility compounds in the transfer tube and the finite residence time in the thermal pretreatment part of the particle number systems. When measuring below 23 nm, diluting at the tailpipe or reducing the residence time in the transfer tube to the dilution tunnel is important in order to minimize such differences.

Effect of selective catalytic reduction on exhaust nonvolatile particle emissions of Euro VI heavy-duty compression ignition vehicles

The nonvolatile particle number (PN) emissions of late technology diesel heavy-duty vehicles (HDV) are very low due to the introduction of Diesel Particulate Filters (DPF). Nevertheless, a large fraction (50%) of particles below the current lower regulated size (23 nm) was recently reported. Moreover, large differences between laboratory and PN Portable Emission Measurement Systems (PN-PEMS) have been observed. In order to better understand such differences, the physical properties of the exhaust aerosol from two Euro VI technology diesel heavy-duty engines were studied. It was found that urea injection leads to formation of nonvolatile particles. The produced particles covered a wide size range spanning from below 10 nm to above 100 nm. As such, they contribute to the regulated PN emissions, with measured concentrations corresponding to as high as 2 × 1011 #/kWh over a World Harmonized Transient Cycle (WHTC). However, a large fraction of them was undetected owing to their small particle size. Low-cutoff size (10 nm) Condensation Particle Counters (CPCs) (which are under discussion to be included in the regulations) measured up to twice as high concentrations. Considering the large particle losses in the sampling systems at this size range, the true concentrations can be two times higher from what the low-cutoff CPCs reported. When the temperature of the SCR system exceeded a threshold of 300 °C, the produced particles were found to be positively charged, increasing the average exhaust aerosol charge up to +3 elementary charges per particle. Scanning Mobility Particle Sizer (SMPS) measurements of non-neutralized samples revealed that even the smallest of them can carry more than one positive charge. The findings of this study can explain the differences reported between PEMS and laboratory systems and especially those based on diffusion charging. They also provide insight for a refinement of technical requirements prescribed in the European PEMS regulation to more accurately quantify the PN emissions from such technologies.

Policy implications of liquefied natural gas use in heavy-duty vehicles: Examples in Canada and British Columbia

This study investigates the greenhouse gas (GHG) emissions from diesel- and liquefied natural gas-fueled (LNG) heavy-duty vehicles (HDVs) in the context of Canada and the province of British Columbia (BC) from 2014 to 2050. HDVs accounted for 18% and 11% of the 2014 GHG emissions from the transportation sector in Canada and BC, respectively. Different scenarios are analyzed using the GHGenius model and recent emissions measurements from LNG HDVs. The low emissions scenario of 1 gCH4/kgLNG indicates that LNG HDVs could reduce GHG emissions by 22% and 30% in Canada and BC, respectively. Also, the analysis shows that Canada’s and BC’s well-to-wheels (WTW) methane emissions should be maintained below 13 and 18 gCH4/kgLNG to produce less GHG emissions from LNG HDVs than their diesel counterparts. If WTW methane emissions are maintained at the current estimated rate of 26 gCH4/kgLNG, replacing diesel with LNG in HDVs would change GHG emissions from +1.7% to +24% for Canada, and from −8% to +16% for BC by 2050. Finally, our study indicates that even methane emissions of 1 gCH4/kgLNG would not be enough to decrease GHG emissions of HDVs by 80% below 2005 levels by 2050 as is the target set by the Government of Canada and BC. However, LNG HDVs do reduce nitrogen oxides and particulate matter emissions. Policy makers could support LNG HDVs for immediate reductions of nitrogen oxides and particulate matter, but should support methane emissions measurements and control campaigns, and other alternative fuels to meet the 80% GHG emission reduction target by 2050.

Minimizing Real Driving Emissions of Heavy Duty Vehicles – Exhaust Systems and Legislation

AbstractTrotz sich stetig verbessernder Luftqualität werden die gesetzlich vorgeschriebenen Immissionsziele in urbanen Gebieten noch nicht eingehalten. Deshalb sind im Automobilbereich – auch im Bereich der Nutzfahrzeuge – weitere Verschärfungen der Grenzwerte und vor allem der Testprozeduren zur Überprüfung in Betrieb befindlicher Fahrzeuge angedacht bzw. bereits verabschiedet. Für Nutzfahrzeuge werden Verfahren zur Bestimmung von Realemissionen und anstehende Verschärfungen der gesetzlichen Prozeduren vorgestellt sowie mögliche Maßnahmen zur Einhaltung dieser strengeren Auflagen.

Solid Particle Number Emission Factors of Euro VI Heavy-Duty Vehicles on the Road and in the Laboratory.

Particulate matter (PM), and in particular ultrafine particles, have a negative impact on human health. The contribution of vehicle PM emissions to air pollution is typically quantified with emission inventories, which need vehicle emission factors as input. Heavy-duty vehicles, although they represent a small percentage of the vehicle population in nearly every major country, contribute the majority of the on-road PM emissions. However, the published data of modern heavy-duty vehicle emissions are scarce, and for the newest Euro VI technologies, almost non-existent. The main objective of this paper is to present Solid Particle Number (SPN) emission factors from Euro VI heavy-duty vehicles using diesel, Compressed Natural Gas (CNG), or Liquefied Natural Gas (LNG). Urban, rural and motorway (highway) emissions were determined on the road at various European cities using SPN Portable Emission Measurement Systems (PEMS). Additional tests on a heavy-duty chassis dynamometer showed that the solid sub-23 nm fraction, which is not covered at the moment in the European regulation, is high, especially for CNG engines. The significant contribution of regeneration events and the effect of ambient temperature and engine cold-start on particle emissions were also discussed.

Relationship between black carbon (BC) and heavy traffic in São Paulo, Brazil

Black carbon (BC) concentration measurements were performed using a multi-angle absorption photometer (MAAP) in the eastern region of São Paulo city (EACH site) showing the dominance of heavy-duty diesel vehicle (HDV) emissions. The measurements were combined with traffic counts from a main road (the Ayrton Senna highway) that connects the city to the airport (Guarulhos) and to other important cities and estimated dilution rates from current NOX measurements to compute vehicle BC emission factors (EFBC). The BC emissions represented real operating traffic conditions and were distinguished between HDVs and light-duty gasoline-driven vehicles (LDVs). The EFBC were estimated according to the time of day to distinguish between different fleet compositions and source emission contributions as well as driving and meteorological conditions. Estimates of both the HDVs (170±259mgkm−1) and the LDVs (41±63mgkm−1) show that emissions from HDVs (EFBC(HDVs)) are around 4 times those from LDVs (EFBC(LDVs)). EF estimates for HDVs are consistent with measurements given in the literature not, however, with emission factors for LDVs whose values are slightly higher than those given in the studies reviewed. The correct determination of the EFBC, both for diesel and gasoline vehicles, is necessary so as to give complete knowledge of the BC impacts on external costs, such as air quality, climate and environment, to establish ad-hoc transportation policies and mitigation strategies.

Determination of Emissions of Heavy-duty Hybrid Vehicles by Means of the Powertrain Method

Determination of Emissions of Heavy-duty Hybrid Vehicles by Means of the Powertrain Method

Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets.

Vehicle emissions contribute to fine particulate matter (PM2.5) and tropospheric ozone air pollution, affecting human health, crop yields and climate worldwide. On-road diesel vehicles produce approximately 20 per cent of global anthropogenic emissions of nitrogen oxides (NOx), which are key PM2.5 and ozone precursors. Regulated NOx emission limits in leading markets have been progressively tightened, but current diesel vehicles emit far more NOx under real-world operating conditions than during laboratory certification testing. Here we show that across 11 markets, representing approximately 80 per cent of global diesel vehicle sales, nearly one-third of on-road heavy-duty diesel vehicle emissions and over half of on-road light-duty diesel vehicle emissions are in excess of certification limits. These excess emissions (totalling 4.6 million tons) are associated with about 38,000 PM2.5- and ozone-related premature deaths globally in 2015, including about 10 per cent of all ozone-related premature deaths in the 28 European Union member states. Heavy-duty vehicles are the dominant contributor to excess diesel NOx emissions and associated health impacts in almost all regions. Adopting and enforcing next-generation standards (more stringent than Euro 6/VI) could nearly eliminate real-world diesel-related NOx emissions in these markets, avoiding approximately 174,000 global PM2.5- and ozone-related premature deaths in 2040. Most of these benefits can be achieved by implementing Euro VI standards where they have not yet been adopted for heavy-duty vehicles.

Particle number and particulate mass emissions of heavy duty vehicles in real operating conditions

The article investigates the issue of PM emissions from HDV vehicles. The theoretical part discusses the problem of emission of this toxic compound in terms of particle structure taking into account the mass and dimensions of PM. Next, the methodology of the research and the results of the measurements performed under the conditions of actual operation were presented. The test drive routes were chosen in accordance with the operational purpose of the selected test vehicles. Two heavy vehicles were used for the study: a tractor with trailer and an eighteen meter long city bus. The test vehicles complied with the Euro V standard, with the second vehicle additionally complying with the EEV standard and being equipped with a DPF. The analysis of the research results was performed in the aspect of determining the operating time densities of vehicles and their drive systems as well as defining their emission characteristics and ecological indicators. PM and PN emissions were measured in the tests and particle size distribution was determined. It was shown that the exhaust gas after treatment system used in the city bus had a positive influence on the ecological indicators and had contributed to the reduction of PN emissions for heavier particles.