scholarly journals Fuel-Operated Auxiliary Heaters Are a Major Additional Source of Vehicular Particulate Emissions in Cold Regions

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1105
Author(s):  
Panu Karjalainen ◽  
Markus Nikka ◽  
Miska Olin ◽  
Sampsa Martikainen ◽  
Antti Rostedt ◽  
...  
Keyword(s):  
Air Quality ◽  
Electric Vehicles ◽  
Particulate Emissions ◽  
Additional Source ◽  
Original Equipment Manufacturer ◽  
Particle Emissions ◽  
Climate Effects ◽  
Equipment Manufacturer ◽  
Car Exhaust ◽  
Global Emissions

Fuel-operated auxiliary heaters (AHs) can be notable sources of particle emissions from vehicles. The emissions of AHs are unregulated, and the number of devices is high; therefore, they make considerable contributions to local air quality, and even the global emissions budget. Experiments for studying the emissions were performed in Finland for a total of eight selected vehicles with Original Equipment Manufacturer (OEM) AHs installed, including both diesel- and gasoline-operated heaters. We present the numerical results of particle emissions and compare the particle concentrations in the AH exhaust to values found in the tailpipe exhaust of the same vehicle. Our results show that the emissions from auxiliary heaters are typically several orders of magnitude higher than of a car exhaust when idling. This raises the question of whether the use of heaters is justified based on the goal to reduce total emissions from vehicle use; furthermore, whether fuel-operated heaters should also be applied in electric vehicles for cabin heating. More research will be needed to characterize the emissions more thoroughly to understand the air quality and climate effects from AHs, and to provide further recommendations on the use of these heaters.

scholarly journals The Potential Impacts of Electric Vehicles on Urban Air Quality in Shanghai City

2021 ◽  
Vol 13 (2) ◽  
pp. 496
Author(s):  
Xiaojian Hu ◽  
Nuo Chen ◽  
Nan Wu ◽  
Bicheng Yin
Keyword(s):  
Air Quality ◽  
Electric Vehicles ◽  
Public Transportation ◽  
Road Traffic ◽  
Urban Air Quality ◽  
Urban Air ◽  
Vehicular Emissions ◽  
Potential Reduction ◽  
Efficient Measure ◽  
Shanghai City

The Shanghai government has outlined plans for the new vehicles used for the public transportation, rental, sanitation, postal, and intra-city freight to be completely powered by electricity by 2020. This paper analyzed the characteristics of vehicle emissions in Shanghai in the past five years. The potential reduction in road traffic related emissions due to the promotion and application of electric vehicle in Shanghai was evaluated. The potential reduction was quantified by vehicular emissions. The vehicular emissions inventories are calculated by the COPERT IV model under the different scenarios, of which the results indicate that promoting electric vehicles is the efficient measure to control all road traffic related emissions and improve urban air quality. The results also provided basis and support for making policies to promote and manage electric vehicles.

scholarly journals Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

2017 ◽  
Vol 17 (14) ◽  
pp. 8739-8755 ◽  
Author(s):  
Jenni Alanen ◽  
Pauli Simonen ◽  
Sanna Saarikoski ◽  
Hilkka Timonen ◽  
Oskari Kangasniemi ◽  
...  
Keyword(s):  
Air Quality ◽  
Natural Gas ◽  
Particulate Emissions ◽  
Engine Exhaust ◽  
Gas Engine ◽  
Secondary Aerosol ◽  
Formation Potential ◽  
Natural Gas Engine ◽  
Evaporation Temperature ◽  
Catalyst Temperature

Abstract. Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6–268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9–20 mg kgfuel−1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize – more than half an hour – which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was measured to have the highest evaporation temperature, and nitrate had the lowest. The evaporation temperature of ammonium depended on the fractions of nitrate and sulfate in the particles. The average volatility of the total aged particles was measured to be lower than that of primary particles, indicating better stability of the aged natural gas engine-emitted aerosol in the atmosphere. According to the results of this study, the exhaust of a natural gas engine equipped with a catalyst forms secondary aerosol when the atmospheric ages in a PAM chamber are several days long. The secondary aerosol matter has different physical characteristics from those of primary particulate emissions.

scholarly journals Impact of Blow-By Gas and Endgap Ring Position on the Variations of Particle Emissions in Gasoline Engines

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7492
Author(s):  
Vincent Berthome ◽  
David Chalet ◽  
Jean-François Hetet
Keyword(s):  
Internal Combustion Engines ◽  
Particulate Emissions ◽  
Combustion Engines ◽  
Spark Ignition Engines ◽  
Particulate Emission ◽  
Particle Emissions ◽  
Gasoline Engines ◽  
System A ◽  
The Impact ◽  
Ring Position

Particulate emission from internal combustion engines is a complex phenomenon that needs to be understood in order to identify its main factors. To this end, it appears necessary to study the impact of unburned gases, called blow-by gases, which are reinjected into the engine intake system. A series of transient tests demonstrate their significant contribution since the particle emissions of spark-ignition engines are 1.5 times higher than those of an engine without blow-by with a standard deviation 1.5 times greater. After analysis, it is found that the decanter is not effective enough to remove completely the oil from the gases. Tests without blow-by gases also have the advantage of having a lower disparity, and therefore of being more repeatable. It appears that the position of the “endgap” formed by the first two rings has a significant impact on the amount of oil transported towards the combustion chamber by the backflow, and consequently on the variation of particle emissions. For this engine and for this transient, 57% of the particulate emissions are related to the equivalence ratio, while 31% are directly related to the ability of the decanter to remove the oil of the blowby gases and 12% of the emissions come from the backflow. The novelty of this work is to relate the particles fluctuation to the position of the endgap ring.

Research on Pedestrian Detection and Vehicle Distance Algorithms of Electric Vehicle Based on Image Processing

2019 ◽  
Vol 34 (05) ◽  
pp. 2054014
Author(s):  
Jingyi Liu
Keyword(s):  
Image Processing ◽  
Air Quality ◽  
Electric Vehicles ◽  
Carbon Dioxide Emissions ◽  
Traffic Accidents ◽  
Pedestrian Detection ◽  
Detection Algorithm ◽  
The Sustainable Development ◽  
Large Expansion ◽  
New Generation

With the economic growth of our country and the continuous improvement of people’s living standards, cars have begun to enter thousands of households and become a necessity for people. However, the rapid growth of the number of automobiles has led to a sustained increase in carbon dioxide emissions and a significant decline in urban air quality, which seriously restricts the sustainable development of cities. With the introduction of the national air quality protection policy, electric vehicles will eventually replace the existing fuel vehicles and become a new generation of transportation for people to travel. At the same time, the large expansion of the number of cars has increased the hidden dangers of traffic accidents. In order to ensure the safety of pedestrians, drivers are given a more intelligent driving environment. This paper presents the research of pedestrian detection and pedestrian distance algorithm based on image processing. By comparing the performance of pedestrian detection algorithm based on SSD with traditional HOG+SVM pedestrian detection algorithm, the results of pedestrian–vehicle distance calculation are detected, and the feasibility and effectiveness of the algorithm are obtained. The results show that the proposed algorithm has good feasibility and practicability, and provide a good reference for the research of pedestrian detection algorithm for electric vehicles.

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