scholarly journals Transient Characterization of Automotive Exhaust Emission from Different Vehicle Types Based on On-Road Measurements

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 64 ◽  
Author(s):  
Chao Ma ◽  
Lin Wu ◽  
Hong-jun Mao ◽  
Xiao-zhen Fang ◽  
Ning Wei ◽  
...  
Keyword(s):  
High Speed ◽  
Exhaust Emissions ◽  
Particulate Filter ◽  
Specific Power ◽  
Vehicle Emission ◽  
Emission Rates ◽  
Automotive Exhaust ◽  
Nucleation Mode ◽  
Medium Speed ◽  
High Emission

Previous works on real-world vehicle emission characteristics have mainly focused on the influences of fuel, speed, vehicle type, elevation, and other factors on vehicle emission quantity and components. However, few studies have investigated the transient trend of automotive exhaust emissions through on-road measurements. The key objective of the present paper was to examine the transient characteristics of exhaust emissions from different vehicle types on the roads of Tianjin. To achieve the goal, a portable emission measurement system (PEMS) was employed to monitor emissions from selected test vehicles—private cars, passenger vehicles, and cargo vehicles. It was found that the high-emission points of test vehicles were mainly distributed in two regions: the high-speed region (speed > 70–90 km/h, vehicle-specific power (VSP) > 0 kW/t) and the medium-speed–acceleration region (20–30 km/h < speed < 60–90 km/h, 0 kW/t <VSP < 12 kW/t). The CO, hydrocarbon (HC), NOx, and particulate number (PN) average emission rates in the high-emission points could be 3.15–14.93 times, 1.93–24.89 times, 3.23–6.03 times, and 3.22–30.27 times of those of average emission rates. The HC, NOx, and PN average emission rates of China IV vehicles in the high-emission points were 2.46–4.92 times, 3.56–6.03 times, and 3.22–13.21 times of those of average emission rates, not less than those of China III (1.93–2.52 times, 2.75–3.90 times, and 9.98–22.34 times). Test vehicles mainly emitted nucleation-mode and Aitken-mode particles, and the increase of the PN concentration emission rate in low-speed and high-speed regions was higher than that in the medium-speed region. The exhaust gas recirculation (EGR) + diesel particulate filter (DPF) could effectively inhibit the Aitken output caused by turbocharged intercooler (CIC). The selective catalytic reduction (SCR) might cause more nucleation-mode particles.

scholarly journals Evaluating the Effects of One-Way Traffic Management on Different Vehicle Exhaust Emissions Using an Integrated Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jieyu Fan ◽  
Kun Gao ◽  
Yingying Xing ◽  
Jian Lu
Keyword(s):  
Traffic Management ◽  
Integrated Approach ◽  
Exhaust Emissions ◽  
Traffic Emissions ◽  
Specific Power ◽  
Emission Measurement ◽  
Emission Rates ◽  
Vehicle Exhaust ◽  
Emission Data ◽  
The Road

One-way traffic management is a recognized traffic organization to improve traffic efficiency and safety, but its effects on different traffic emissions remains unclear. This paper aims to investigate the impacts of one-way traffic management on three typical vehicle exhaust emissions including Carbonic Oxide (CO), Hydrocarbon Compounds (HC), and Nitrogen Oxides (NOx) in a traffic system using an integrated approach. Field experiment was conducted to collect the vehicular emission data under different traffic conditions using the onboard portable emission measurement system. An instantaneous emission model (i.e., Vehicle Specific Power) is calibrated using the collected field emission data and is incorporated into the microscopic traffic simulation tool VISSIM for quantifying the emissions before and after one-way traffic management through simulation. Two scenarios based on real networks and traffic demands of peak hours in part areas of Shanghai are developed for simulation and evaluation. The results show that in the intersections, the emission rates of COHC, NOx after one-way traffic management is significantly reduced by 20.46%, 21.29% and 21.06%, respectively. In the road sections, the emission rates of CO, HC, NOx in the road sections decrease by 23.38% and 26.29%. The overall CO, HC, NOx emissions in the studied network reduce by 21.34%, 22.29% and 23.77% separately due to one-way traffic management. The results provide insights into the derivative effects of one-way traffic management on traffic emissions in the intersections, road sections and network levels, and thus support scientific traffic management for promoting the sustainability of transport system.

scholarly journals Emission performance of major ship classes: An estimation based on a new set of emission factors and realistic activity profile data

2021 ◽  
Vol 899 (1) ◽  
pp. 012005
Author(s):  
Achilleas Grigoriadis ◽  
Sokratis Mamarikas ◽  
Leonidas Ntziachristos
Keyword(s):  
High Speed ◽  
Global Scale ◽  
Emission Factors ◽  
Emission Rates ◽  
Activity Profile ◽  
Activity Data ◽  
Emission Performance ◽  
Medium Speed ◽  
High Speed Diesel ◽  
Sulphur Oxides

Abstract The maritime sector significantly contributes on the major environmental problems that humanity is being confronted with their consequences. The Greenhouse Gases (GHGs) emitted from the sector, which are responsible for the global phenomenon of climate change, are estimated in 2,89% of total anthropogenic GHGs. Ships are also an important source of local air-quality degradation in coastal areas by emitting major quantities of pollutants such as Nitrogen Oxides (NOx), Sulphur Oxides (SOx) and Particulate Matter (PM). The overall emitted quantities of the sector seem not to be equally allocated to the major ship classes (containers, dry and liquid bulk carriers, cruise ships, ro-ro ships etc.), even though the engine technologies that are being used in these classes are approximately the same (slow speed, medium speed, high speed diesel engines). A factor of differentiation among the ship types is the activity profile. Depending on the ship type, engines (main, auxiliary, boilers) present different power needs and therefore are being operated at different load points which among others are related with the sailing profile (cruising, maneuvering, hoteling), the cargo type and weight conditions (laden, ballast). In this context the target of the present paper is to evaluate the emission performance of the major ship classes. This evaluation is performed by using a new set of engine load-dependent Emission Factors for ships, which have been derived by a statistical analysis of emission rates found in literature, in combination with average activity profiles per ship type as these are found in dedicated shipping inventory databases and in literature. These activity data concern a global scale of consideration. Results aim to highlight the differences and similarities in the emission performance of ship types, enhancing the understanding of policy makers and ship operators, on the principle of tackling pollutants especially at ports, close to cities.

scholarly journals Evaluation of Medium Speed Diesel generator sets and energy storage technologies as alternatives for reducing fuel consumption and exhaust emissions in electric propulsion systems for PSVs

2016 ◽  
Vol 9 (18) ◽  
pp. 49 ◽  
Author(s):  
Cristian A. Morales Vásquez
Keyword(s):  
Energy Storage ◽  
Fuel Consumption ◽  
Electric Propulsion ◽  
High Speed ◽  
Exhaust Emissions ◽  
Diesel Generator ◽  
Medium Speed ◽  
High Speed Diesel ◽  
Storage Technologies ◽  
Generator Sets

The use of electric propulsion systems in PSVs in Brazil has recently increased, leading to be the standard for most support vessels. In those ships, the common arrangement uses high speed Diesel generator sets for power generation and induction motors driving propellers, reporting significant reductions in the fuel consumption and exhaust emissions compared with mechanically propelled PSVs. However, further abatements in these parameters could be achieved by implementing other technologies for power production. In this work, the use of medium- speed Diesel generator sets and energy storage technologies in electrically propelled PSVs is evaluated. For the above, the fuel consumption, exhaust emissions, mass, volume and acquisition costs of four arrangements are estimated and compared. Two of the arrangements are equipped with medium-speed Diesel generator sets, two with energy storage units and one with high-speed Diesel generator sets. Energy storage appears as interesting alternative for decreasing fuel consumption and emissions by optimal loading of Diesel engines. Medium speed generators also showed reductions in fuel consumption, but highest emissions. The arrangements with high-speed generators presented the lowest mass, volume and acquisition costs. 

scholarly journals Potential of big data approach for remote sensing of vehicle exhaust emissions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lijun Hao ◽  
Hang Yin ◽  
Junfang Wang ◽  
Xiaohu Wang ◽  
Yunshan Ge
Keyword(s):  
Remote Sensing ◽  
Big Data ◽  
Vehicle Emissions ◽  
Exhaust Emissions ◽  
Specific Power ◽  
Scientific Management ◽  
Vehicle Emission ◽  
Vehicle Exhaust ◽  
Threshold Limit ◽  
Driving Conditions

AbstractAt present, remote sensing (RS) is applied in detecting vehicle exhaust emissions, and usually the RS emission results in a definite vehicle specific power (VSP) range are used to evaluate vehicle emissions and identify high-emitting vehicles. When the VSP exceeds this range, the corresponding vehicle emission RS data will not be used to assess vehicle emissions. This method is equivalent to setting only one VSP Bin qualified for vehicle emission evaluation, and generally only one threshold limit is given for each emission pollutant without considering the fluctuation characteristics of vehicle emissions with VSP. Therefore, it is easy to cause misjudgment in identifying high-emitting vehicles and is not conducive to scientific management of vehicle emissions. In addition, the vehicle emissions outside the selected VSP Bin are more serious and should be included in the scope of supervision. This research proposed the methods of vehicle classifications and VSP Binning in order to categorize the driving conditions of each kind of vehicles, and a big data approach was proposed to analyze the vehicle emission RS data in each VSP Bin for vehicle emission evaluation.

scholarly journals Scenario Analyses of Exhaust Emissions Reduction through the Introduction of Electric Vehicles into the City

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 2030
Author(s):  
Marianna Jacyna ◽  
Renata Żochowska ◽  
Aleksander Sobota ◽  
Mariusz Wasiak
Keyword(s):  
Inner City ◽  
Electric Vehicles ◽  
Transport Model ◽  
Exhaust Emissions ◽  
Scenario Analyses ◽  
High Emission ◽  
Clean Air ◽  
The One ◽  
The City

In recent years, policymakers of urban agglomerations in various regions of the world have been striving to reduce environmental pollution from harmful exhaust and noise emissions. Restrictions on conventional vehicles entering the inner city are being introduced and the introduction of low-emission measures, including electric ones, is being promoted. This paper presents a method for scenario analysis applied to study the reduction of exhaust emissions by introducing electric vehicles in a selected city. The original scenario analyses relating to real problems faced by contemporary metropolitan areas are based on the VISUM tool (PTV Headquarters for Europe: PTV Planung Transport Verkehr AG, 76131 Karlsruhe, Germany). For the case study, the transport model of the city of Bielsko-Biala (Poland) was used to conduct experiments with different forms of participation of electric vehicles on the one hand and traffic restrictions for high emission vehicles on the other hand. Scenario analyses were conducted for various constraint options including inbound, outbound, and through traffic. Travel time for specific transport relations and the volume of harmful emissions were used as criteria for evaluating scenarios of limited accessibility to city zones for selected types of vehicles. The comparative analyses carried out showed that the introduction of electric vehicles in the inner city resulted in a significant reduction in the emission of harmful exhaust compounds and, consequently, in an increase in the area of clean air in the city. The case study and its results provide some valuable insights and may guide decision-makers in their actions to introduce both driving ban restrictions for high-emission vehicles and incentives for the use of electric vehicles for city residents.

On-Road Gaseous Emission Characteristics of China IV CNG Bus in Shanghai

2013 ◽  
Vol 690-693 ◽  
pp. 1864-1871 ◽  
Author(s):  
Di Ming Lou ◽  
Si Li Qian ◽  
Zhi Yuan Hu ◽  
Pi Qiang Tan
Keyword(s):  
Emission Factor ◽  
High Speed ◽  
Idle Time ◽  
Operating Conditions ◽  
Vehicle Emission ◽  
Emission Characteristics ◽  
Emission Measurement ◽  
Gaseous Emissions ◽  
Average Speed ◽  
Portable Emission Measurement System

In this paper, on-road CO, THC, NOX, CO2 gaseous emissions characteristics of china IV CNG bus were analyzed based on on-road vehicle emission test in the peak and non-peak hours of city traffic in Shanghai using a portable emission measurement system (PEMS). The experimental results reveal that: compared with the condition results in the non-peak hours, it (conditions in the peak hours) have lower average speed, longer idle time and shorter high speed time; the NOX emission factor and rate in the peak hour reduced by 5.66% and 70.2%; the CO, HC, CO2 emissions factors are increased by 47.2%, 32.6%, 20.8%, and the CO, HC, CO2 emissions rates reduced by 1.94%, 26.5%, 48.7% respectively, compared with that in the non-peak hours; The CO, HC, NOX, CO2 emissions factors all decreased as bus speed increased, while they increased as bus acceleration increased; the gaseous emissions rates all increased as bus speed increased; both the emissions factors and emissions rates contributions are highest at accelerations, higher at cruise speeds, and the lowest at decelerations for non-idling buses; the emissions rates under the condition of idling is lowest; gaseous emissions contribution under the various operating conditions has displayed certain correlations with the percentage of the time for different operating conditions.

Filtration Efficiency and Regeneration Behavior in a Catalytic Diesel Particulate Filter with the Use of Diesel/Polyoxymethylene Dimethyl Ether Mixture

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1425
Author(s):  
Hao Chen ◽  
Xin Sun ◽  
Xiaochen Wang ◽  
Fengyu Sun ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Removal Efficiency ◽  
Diesel Particulate Filter ◽  
Energy Requirement ◽  
Filtration Efficiency ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Accumulation Mode ◽  
Nucleation Mode ◽  
Particulate Number

Polyoxymethylene dimethyl ether (PODEn) is a promising diesel additive, especially in particulate matter reduction. However, how PODEn addition affects the filtration efficiency and regeneration process of a catalytic diesel particulate filter is still unknown. Therefore, this experimental work investigated the size-dependent particulate number removal efficiency under various engine loads and exhaust gas recirculation ratios when fueling with diesel and diesel/PODEn mixture. In addition, the regeneration behavior of the cDPF was studied by determining the break-even temperatures for both tested fuels. The results showed that the cDPF had lower removal efficiencies in nucleation mode particles but higher filtration efficiencies in accumulation mode particles. In addition, the overall filtration efficiency for P10 particles was higher than that for D100 particles. Positioning the upstream cDPF, increasing the EGR ratio slightly decreased the number concentration of nucleation mode particles but greatly increased that of accumulation mode particles. However, increasing the EGR ratio decreased the removal efficiency of nanoparticles, and this effect was more apparent for the P10 case. Under the same period of soot loading, the pressure drop of P10 fuel was significantly lower than that of diesel fuel. In addition, a significantly lower BET was observed for the P10 fuel, in comparison with D100 fuel. In conclusion, adopting cDPF is beneficial for fueling with P10 in terms of the overall filtration efficiency in the particulate number and the lower input energy requirement for active regeneration. However, with the addition of EGR, the lower filtration efficiencies of nanoparticles should be concerned, especially fueling with diesel/PODEn mixture.

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