scholarly journals Assessment of impact of vehicle traffic conditions: urban, rural and highway, on the results of pollutant emissions inventory

2021 ◽  
Vol 60 (4) ◽  
pp. 57-69
Author(s):  
Katarzyna Bebkiewicz ◽  
Zdzisław Chłopek ◽  
Hubert Sar ◽  
Krystian Szczepański ◽  
Magdalena Zimakowska-Laskowska

The use of motor vehicles varies considerably under distinct traffic conditions: in cities, outside cities as well as on motorways and expressways. The impact of road traffic on the natural environment has been studied for many years, including in terms of the nature of the operation of motor vehicles. This problem is particularly important in highly urbanized areas, where traffic congestion is the source of increased emissions of harmful compounds contained in exhaust gases. For this reason, many cities have traffic restrictions, especially for those cars that do not meet the most stringent emission standards. Environmental protection is the driving force behind the development of modern combustion engine supply systems, which allow for proper control of the combustion of petroleum-derived fuels. The exhaust gas cleaning systems in the form of catalytic converters or particulate matter filters are also playing a very important role. Considerable differences in internal combustion engine operating states, both static and dynamic, result in important differences in pollutant emissions. Likewise, the national annual pollutant emission is affected by the share of distances travelled by vehicles under various traffic conditions. At the same time, it is very difficult to estimate exhaust emissions from road transport sources. Very interesting method of emission estimation is the application of the data included in the emission inventory which are a valuable source of information on exhaust emissions under various operating conditions. In the present study, the annual pollutant emissions were analyzed: at a national level (total pollutant emission) and in distinct traffic conditions. There were found large differences between individual pollutants’ shares in the emissions from vehicles under the tested traffic conditions. This is particularly evident for nitrogen oxides with the highest emission share outside cities, as opposed to other substances with the highest emission shares in cities, where traffic congestion is taking place.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1046
Author(s):  
Maksymilian Mądziel ◽  
Tiziana Campisi ◽  
Artur Jaworski ◽  
Giovanni Tesoriere

Urban agglomerations close to road infrastructure are particularly exposed to harmful exhaust emissions from motor vehicles and this problem is exacerbated at road intersections. Roundabouts are one of the most popular intersection designs in recent years, making traffic flow smoother and safer, but especially at peak times they are subject to numerous stop-and-go operations by vehicles, which increase the dispersion of emissions with high particulate matter rates. The study focused on a specific area of the city of Rzeszow in Poland. This country is characterized by the current composition of vehicle fleets connected to combustion engine vehicles. The measurement of the concentration of particulate matter (PM2.5 and PM10) by means of a preliminary survey campaign in the vicinity of the intersection made it possible to assess the impact of vehicle traffic on the dispersion of pollutants in the air. The present report presents some strategies to be implemented in the examined area considering a comparison of current and project scenarios characterized both by a modification of the road geometry (through the introduction of a turbo roundabout) and the composition of the vehicular flow with the forthcoming diffusion of electric vehicles. The study presents an exemplified methodology for comparing scenarios aimed at optimizing strategic choices for the local administration and also shows the benefits of an increased electric fleet. By processing the data with specific tools and comparing the scenarios, it was found that a conversion of 25% of the motor vehicles to electric vehicles in the current fleet has reduced the concentration of PM10 by about 30% along the ring road, has led to a significant reduction in the length of particulate concentration of the motorway, and it has also led to a significant reduction in the length of the particulate concentration for the access roads to the intersection.


2018 ◽  
Vol 196 ◽  
pp. 04065
Author(s):  
Liparit Badalyan ◽  
Vladimir Kurdjukov ◽  
Alla Ovcharenko

Modern development of the construction industry involves accounting and assessment of operating conditions of structures. Excessive technological environmental impact can lead to economic losses and a decrease in the efficiency of investment projects in construction. Mobile sources emission record is an important component of the ecosystem state diagnosis in modern cities. For scientifically substantiated and reliable determination of the mass flow of the motor vehicles pollutants it is necessary to take into account the mixture formation and combustion of the working mixture in the internal combustion engine. The article describes the authors' approach to calculating the volumetric flow rate of exhaust gases based on the characteristics of the vehicle's transport operations available for operational control. Studies have shown that, when using a particular fuel, the determination of the volume flow rate of exhaust gases can be reduced to finding the power of the engine . In addition, the composition changes of the fuel (or fuel replacement) and the regulation of the effective power of the engine (by organization of traffic) allow to influence on the volume and composition of the emission of exhaust gases of vehicles and on the pollution of the urban environment in general. The results of the studies make it easier to calculate the mass of pollutant emissions by the transport stream into the outer air and can be used as preliminary data to assess the negative anthropogenic impact on the ecosystem.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 935
Author(s):  
Monika Andrych-Zalewska ◽  
Zdzislaw Chlopek ◽  
Jerzy Merkisz ◽  
Jacek Pielecha

The paper describes the methodology of research of exhaust emissions from a combustion engine under engine states determined by the vehicle actual operation in the RDE test. The processes of quantities determining the vehicle motion and engine states have been recorded, along with the exhaust emission intensity. Based on the developed research methodology, zero-dimensional characteristics of the processes of the emission intensity have been determined under the conditions of urban, rural and motorway traffic, as well as in the entire test. The authors also determined the average specific distance exhaust emissions under the conditions of urban, rural and motorway traffic, as well as in the entire test. Based on the above results, the unique characteristics of the relation of the average specific distance emissions and the average vehicle speed have been obtained. The obtained characteristics may be used in the modeling of exhaust emissions from motor vehicles under actual traffic conditions. The authors also explored the sensitivity of the average specific distance emissions to the vehicle driving style.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.


Author(s):  
Alex Oliveira ◽  
Junfeng Yang ◽  
Jose Sodre

Abstract This work evaluated the effect of cooled exhaust gas recirculation (EGR) on fuel consumption and pollutant emissions from a diesel engine fueled with B8 (a blend of biodiesel and Diesel 8:92%% by volume), experimentally and numerically. Experiments were carried out on a Diesel power generator with varying loads from 5 kW to 35 kW and 10% of cold EGR ratio. Exhaust emissions (e.g. THC, NOX, CO etc.) were measured and evaluated. The results showed mild EGR and low biodiesel content have minor impact of engine specific fuel consumption, fuel conversion efficiency and in-cylinder pressure. Meanwhile, the combination of EGR and biodiesel reduced THC and NOX up to 52% and 59%, which shows promising effect on overcoming the PM-NOX trade-off from diesel engine. A 3D CFD engine model incorporated with detailed biodiesel combustion kinetics and NOx formation kinetics was validated against measured in-cylinder pressure, temperature and engine-out NO emission from diesel engine. This valid model was then employed to investigate the in-cylinder temperature and equivalence ratio distribution that predominate NOx formation. The results showed that the reduction of NOx emission by EGR and biodiesel is obtained by a little reduction of the local in-cylinder temperature and, mainly, by creating comparatively rich combusting mixture.


Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1604
Author(s):  
Tao Zhu ◽  
Furong Li ◽  
Wenfeng Niu ◽  
Zijun Gao ◽  
Yiwei Han ◽  
...  

Monitoring of toxic and hazardous air pollutants (HAPs) in a petrochemical company in the Beijing-Tianjin-Hebei region of China to assess the impact of HAPs on the health risks of workers in the petrochemical company. The samples were tested by solid-phase adsorption thermal desorption/gas chromatography-mass spectrometry (HJ734-2014), and the pollutant emission list was obtained. According to the pollutant emission inventory, it can be seen that benzene, toluene and xylene are the main components of toxic and harmful air pollutants emitted by the petrochemical enterprise. The method of combining actual monitoring and CALPUFF model prediction was used to evaluate the impact of the toxic and harmful air pollutants emitted by the enterprise on the health of workers. The risk characterization results show that when benzene is the maximum concentration value predicted by the model, it will pose a carcinogenic risk to the factory workers. Therefore, based on the results of this study, it is recommended not to allow residents to live within the predicted concentration range of the model. The results of this study can enable China’s oil refining industry to better understand the characteristics of pollutant emissions from petrochemical companies in the Beijing-Tianjin-Hebei region. Moreover, the results of this study can be used as a policy basis for improving the health of workers in petrochemical enterprises, and are of great significance to the protection of public health.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4561 ◽  
Author(s):  
José R. Serrano ◽  
Francisco J. Arnau ◽  
Jaime Martín ◽  
Ángel Auñón

Growing interest has arisen to adopt Variable Valve Timing (VVT) technology for automotive engines due to the need to fulfill the pollutant emission regulations. Several VVT strategies, such as the exhaust re-opening and the late exhaust closing, can be used to achieve an increment in the after-treatment upstream temperature by increasing the residual gas amount. In this study, a one-dimensional gas dynamics engine model has been used to simulate several VVT strategies and develop a control system to actuate over the valves timing in order to increase diesel oxidation catalyst efficiency and reduce the exhaust pollutant emissions. A transient operating conditions comparison, taking the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC) as a reference, has been done by analyzing fuel economy, HC and CO pollutant emissions levels. The results conclude that the combination of an early exhaust and a late intake valve events leads to a 20% reduction in CO emissions with a fuel penalty of 6% over the low speed stage of the WLTC, during the warm-up of the oxidation catalyst. The same set-up is able to reduce HC emissions down to 16% and NOx emission by 13%.


Author(s):  
Amin Akbari ◽  
Vincent McDonell ◽  
Scott Samuelsen

Co firing of natural gas with renewable fuels such as hydrogen can reduce greenhouse gas emissions, and meet other sustainability considerations. At the same time, adding hydrogen to natural gas alters combustion properties, such as burning speeds, heating values, flammability limits, and chemical characteristics. It is important to identify how combustion stability relates to fuel mixture composition in industrial gas turbines and burners and correlate such behavior to fuel properties or operating conditions. Ultimately, it is desired to predict and prevent operability issues when designing a fuel flexible gas turbine combustor. Fuel interchangeability is used to describe the ability of a substitute fuel composition to replace a baseline fuel without significantly altering performance and operation. Any substitute fuel, while maintaining the same heating load as the baseline fuel, must also provide stable combustion with low pollutant emissions. Interchangeability indices try to predict the impact of fuel composition on lean blowoff and flashback. Correlations for operability limits have been reported, though results are more consistent for blowoff compared to flashback. Yet, even for blowoff, some disagreement regarding fuel composition effects are evident. In the present work, promising correlations and parameters for lean blow off and flashback in a swirl stabilized lean premixed combustor are evaluated. Measurements are conducted for fuel compositions ranging from pure natural gas to pure hydrogen under different levels of preheat and air flow rates. The results are used to evaluate the ability of existing approaches to predict blowoff and flashback. The results show that, while a Damköhler number approach for blowoff is promising, important considerations are required in applying the method. For flashback, the quench constant parameter suggested for combustion induced vortex breakdown was applied and found to have limited success for predicting flashback in the present configuration.


2019 ◽  
Vol 179 (4) ◽  
pp. 86-92
Author(s):  
Mieczysław DZIUBIŃSKI ◽  
Ewa SIEMIONEK ◽  
Artur DROZD ◽  
Michał ŚCIRKA ◽  
Adam KISZCZAK ◽  
...  

The article discusses the impact of ignition system damage on the emission of toxic subcategories in a spark-ignition internal combustion engine. The aim of the work was to develop an analytical model of ignition system diagnostics, test performance and comparative analysis of the results of simulations and experiments. The model developed allows to analyse the basic parameters of the ignition system affecting the content of toxic substances in the exhaust. Experimental tests were carried out using the MAHA MGT5 exhaust gas analyser for four different combustion engines fueled with petrol at various operating conditions. During the tests, the content of toxic substances in the exhaust gas of a properly working engine and the engine working with damage to the ignition system were registered. The tests will be used to assess the impact of the damage of the spark-ignition engine on the emission of individual components of toxic fumes.


2021 ◽  
Vol 15 (2) ◽  
pp. 5-14
Author(s):  
Carmelia Mariana Dragomir Balanica ◽  
Ciprian Cuzmin ◽  
Cecilia Serban ◽  
Cristian Muntenita

Road transport, including accessibility and individual mobility is considered unanimously as a fundamental element of contemporary living. The study area is considering Braila County with a total population of around over 305,000. The area it is well served by 6 national roads, 27 county roads and 42 communal roads and contains some of the most heavily trafficked stretches of road in the Romania. The emissions analysed in this study CH4, CO, CO2, N2O, NH3, NOx, PM2.5 and PM10, were collected by the Agency for Environmental Protection Braila during 2015-2019 based on questionnaires according to EMEP/EEA air pollutant emission inventory guidebook. The highest level of pollutant emissions was recorded in 2017, more exactly 191714,5 Megatons. In this article we analysed five categories of pollution sources: Passenger car, Light commercial trucks, Heavy-duty vehicles, Motorcycles and Non - Road vehicles and other mobile equipment. With the exception of CO2, N2O and NH3, pollutant emissions decreased for the eight pollutants analysed.


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