کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6478264 | 1427916 | 2017 | 8 صفحه PDF | دانلود رایگان |
The formation of ultrafine particulate matter in the early stage of high-sodium lignite combustion was quantitatively investigated in a downward Hencken flat-flame burner under two ambiences of 1200Â K and 1500Â K. Spatially resolved measurement of the ultrafine particle size distributions (PSDs) was made by using a scanning mobility particle sizer with a high sensitivity in the 4.45-156.8Â nm size range. The experimental results indicate that, during the residence time of coal particles from â¼20 ms to â¼40 ms, the number PSDs under 1200Â K exhibit bi-modal while those under 1500Â K keep uni-modal. As time is evolved, the detected peak of ultrafine particles moves from 10.62Â nm to 80.54Â nm under 1200Â K, while that from 10.76Â nm to 38.46Â nm under 1500Â K. Then, a physico-chemical mechanism responsible for the incipient formation of ultrafine particles during high-sodium lignite combustion was developed and computed by solving a discrete-sectional population balance model. The number PSDs of ultrafine particles and the dynamic behavior of Na release measured in experiments are consistent with the simulation results. It is further divulged that the intrinsic cause of the PSD transition between different ambient temperatures is the high concentration of newly formed particles, instead of the enhanced collision frequency.
Journal: Proceedings of the Combustion Institute - Volume 36, Issue 2, 2017, Pages 2083-2090