کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6338576 1620370 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Metal nanoparticles in diesel exhaust derived by in-cylinder melting of detached engine fragments
ترجمه فارسی عنوان
نانوذرات فلزی در اگزوز دیزل مشتق شده از طریق ذوب شدن سیلندر قطعات جدا شده موتور
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
چکیده انگلیسی


- Traffic-related metal nanoparticle emissions can pose environmental and health concerns.
- Fe3O4 nanoparticle agglomerates occur in diesel exhaust.
- Steel fragments detached from cylinder engine parts can melt in the combustion chamber.
- A hitherto neglected mechanism of metal nanoparticle formation from internal combustion engines is suggested.

A wide range of environmental and health effects are linked to combustion-generated pollutants related to traffic. Nanoparticles, in particular, are a major concern for humans since they can be inhaled and have potentially toxic effects. The variability and sources of combustion-related nanoparticle pollutants remain inadequately investigated. Here we report the presence of ca. 5-100 nm large Fe3O4 nanoparticles, in form of agglomerates, in diesel exhaust. The mode of occurrence of these nanoparticles, in combination with their chemical composition matching that of steel indicate that they derive by melting of engine fragments in the combustion chamber and subsequent crystallization during cooling. To evaluate this hypothesis, we applied CFD simulations of material transport in the cylinder of a diesel engine, assuming detachment of steel fragments from various sites of the cylinder. The CFD results show that fragments ≤20 μm in size dislodged from the piston surface or from the fuel nozzle interior can be indeed transported to such hot areas of the combustion chamber where they can melt. The simulation results concur with the experimental observations and point out that metal nanoparticle formation by in-cylinder melting of engine fragments can occur in diesel engines. The present study proposes a hitherto neglected formation mechanism of metal nanoparticle emissions from internal combustion engines raising possible environmental and health concerns, especially in urban areas.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 101, January 2015, Pages 34-40
نویسندگان
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