Analysis of fractal particles from diesel exhaust using a scanning-mobility particle sizer and laser-induced incandescence

2010 ◽  
Vol 41 (6) ◽  
pp. 531-540 ◽  
Author(s):  
Jongil Park ◽  
Jaehyuk Yoon ◽  
Soonho Song ◽  
Kwang Min Chun
Author(s):  
Christoph Hassa ◽  
Eggert Magens ◽  
Lena Voigt ◽  
Olaf Diers ◽  
Ingo Otterpohl ◽  
...  

Abstract The production and emission of soot from Kerosene JET-A1 and a blend of a different JET-A1 and 30% HEFA was investigated in a realistic multisector combustor of Rolls-Royce Deutschland. Soot concentration measurements were performed at the exit as well as in the optically accessible primary zone of the combustor. There, information of soot mass concentration is available from measurements using Laser induced incandescence and Laser extinction. At the exit of the combustor, soot particles were measured with a scanning mobility particle sizer. This resulted in particle size distributions from which soot number and mass concentrations were calculated. Within the pressurized combustor, low load points, scaled cruise and high load points were operated. For the investigated operating range which reaches to ∼50% of max pressure but preserves engine AFR, up to 75% reduction of both soot particle mass and number EI were observed for the HEFA blend in part load and 50% at the scaled high-power condition. However at the end of the primary zone, a reduction increasing with soot concentration and fuel load was recorded. This guides attention to the different oxidation characteristics for the fuels in the investigated combustor. Accordingly, larger particles were consistently measured at the exit for the HEFA blend.


Author(s):  
Malte Bierwirth ◽  
Vinzent Olszok ◽  
Varun Aiyar Ganesan ◽  
Jalal Poostforooshan ◽  
Alfred P. Weber

Gefahrstoffe ◽  
2020 ◽  
Vol 80 (01-02) ◽  
pp. 25-32
Author(s):  
C. Asbach ◽  
T. A. J. Kuhlbusch ◽  
U. Quass ◽  
H. Kaminski

Seit Anfang 2009 werden an einer städtischen Hintergrundmessstation in Mülheim-Styrum im westlichen Ruhrgebiet Anzahlkonzentration, Anzahlgrößenverteilung und lungendeponierbare Oberflächenkonzentration submikroner und ultrafeiner Partikel gemessen. Die dazu eingesetzten Messgeräte Scanning Mobility Particle Sizer (SMPS) und Nanoparticle Surface Area Monitor (NSAM) erwiesen sich als gut geeignet für derartige Messaufgaben. Insbesondere das NSAM ist sehr robust und zuverlässig und wird daher neben der Bestimmung der lungendeponierbaren Oberflächenkonzentration auch zur Funktionsüberwachung des SMPS verwendet. Die ultrafeinen Partikel an der Messstation stammen zu einem großen Teil von einer nahegelegenen Autobahn sowie diversen anderen Quellen in der näheren Umgebung. Der etwa 20 km südlich gelegene Flughafen Düsseldorf scheint keinen merklichen Einfluss zu haben. Eine Auswertung der Wochengänge zeigte überraschenderweise, dass in allen Jahren samstagnachts die im Wochenverlauf höchste Anzahlkonzentration von Partikeln >100 nm gemessen wurde. Während an allen anderen Wochentagen die mittleren Konzentrationen seit 2009 kontinuierlich gesunken sind, blieb die Höhe des Maximums in der Nacht von Samstag auf Sonntag nahezu konstant, was auf eine unveränderte, zeitlich sehr begrenzte Quelle hindeutet.


2018 ◽  
Vol 47 (7) ◽  
pp. 777-787 ◽  
Author(s):  
Simon E. Wawra ◽  
Martin Thoma ◽  
Johannes Walter ◽  
Christian Lübbert ◽  
Thaseem Thajudeen ◽  
...  

2016 ◽  
Vol 9 (1) ◽  
pp. 103-114 ◽  
Author(s):  
G. I. Gkatzelis ◽  
D. K. Papanastasiou ◽  
K. Florou ◽  
C. Kaltsonoudis ◽  
E. Louvaris ◽  
...  

Abstract. An experimental methodology was developed to measure the nonvolatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a nonvolatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol (OA; 40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50–60 % of the particles had a nonvolatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon with an 80 % contribution, while OA was responsible for another 15–20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.


2019 ◽  
pp. 146808741987978
Author(s):  
Flavio Dal Forno Chuahy ◽  
Tyler Strickland ◽  
Nicholas Ryan Walker ◽  
Sage L Kokjohn

Advancements in catalytic reforming have demonstrated the ability to generate syngas (a mixture of CO and hydrogen) from a single hydrocarbon stream. This syngas mixture can then be used to replace diesel fuel and enable dual-fuel combustion strategies. The role of port-fuel injected syngas, composed of equal parts hydrogen and carbon monoxide by volume, was investigated experimentally for soot reduction benefits under diesel pilot ignition and reactivity controlled compression ignition strategies. Particle size distribution measurements were made with a scanning mobility particle sizer and condensation particle counter for different levels of syngas substitution. To explain the experimental results, computational fluid dynamics simulations utilizing a detailed stochastic soot model were used to validate and initialize additional simulations that isolate mixing and chemistry effects. Based on these simulations, the influence of adding syngas on soot particle size and quantity is discussed.


2019 ◽  
Vol 19 (18) ◽  
pp. 11985-12006 ◽  
Author(s):  
Peter J. Marinescu ◽  
Ezra J. T. Levin ◽  
Don Collins ◽  
Sonia M. Kreidenweis ◽  
Susan C. van den Heever

Abstract. A quality-controlled, 5-year dataset of aerosol number size distributions (particles with diameters (Dp) from 7 nm through 14 µm) was developed using observations from a scanning mobility particle sizer, aerodynamic particle sizer, and a condensation particle counter at the Department of Energy's Southern Great Plains (SGP) site. This dataset was used for two purposes. First, typical characteristics of the aerosol size distribution (number, surface area, and volume) were calculated for the SGP site, both for the entire dataset and on a seasonal basis, and size distribution lognormal fit parameters are provided. While the median size distributions generally had similar shapes (four lognormal modes) in all the seasons, there were some significant differences between seasons. These differences were most significant in the smallest particles (Dp<30 nm) and largest particles (Dp>800 nm). Second, power spectral analysis was conducted on this long-term dataset to determine key temporal cycles of total aerosol concentrations, as well as aerosol concentrations in specified size ranges. The strongest cyclic signal was associated with a diurnal cycle in total aerosol number concentrations that was driven by the number concentrations of the smallest particles (Dp<30 nm). This diurnal cycle in the smallest particles occurred in all seasons in ∼50 % of the observations, suggesting a persistent influence of new particle formation events on the number concentrations observed at the SGP site. This finding is in contrast with earlier studies that suggest new particle formation is observed primarily in the springtime at this site. The timing of peak concentrations associated with this diurnal cycle was shifted by several hours depending on the season, which was consistent with seasonal differences in insolation and boundary layer processes. Significant diurnal cycles in number concentrations were also found for particles with Dp between 140 and 800 nm, with peak concentrations occurring in the overnight hours, which were primarily associated with both nitrate and organic aerosol cycles. Weaker cyclic signals were observed for longer timescales (days to weeks) and are hypothesized to be related to the timescales of synoptic weather variability. The strongest periodic signals (3.5–5 and 7 d cycles) for these longer timescales varied depending on the season, with no cyclic signals and the lowest variability in the summer.


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