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Temporally and spectrally resolved images of single burning pulverized wheat straw particles

Weng, Wubin LU ; Costa, Mário; Li, Zhongshan LU and Aldén, Marcus LU (2018) In Fuel 224. p.434-441
Abstract

This work focuses into the combustion behaviour of single wheat straw particles with the aim of providing a quantitative description of the particle burning process from ignition to the early stages of the char oxidation. The single particles, in the size range 224–250 µm, were injected upward into a confined region with hot combustion products, produced by a flat flame McKenna burner, with a mean temperature of 1550 K and a mean dry O2 concentration of 6.5 vol%. Spectral emission data and temporally resolved images of the single burning particles were obtained with a spectrometer and an ICCD camera, respectively. To obtain spectrally resolved images the camera was equipped with different band-pass filters. Overall, the... (More)

This work focuses into the combustion behaviour of single wheat straw particles with the aim of providing a quantitative description of the particle burning process from ignition to the early stages of the char oxidation. The single particles, in the size range 224–250 µm, were injected upward into a confined region with hot combustion products, produced by a flat flame McKenna burner, with a mean temperature of 1550 K and a mean dry O2 concentration of 6.5 vol%. Spectral emission data and temporally resolved images of the single burning particles were obtained with a spectrometer and an ICCD camera, respectively. To obtain spectrally resolved images the camera was equipped with different band-pass filters. Overall, the results demonstrate the ability of the present experimental setup and associated optical diagnostics to gather quantitative information of the combustion process of single pulverized solid fuel particles. The emission spectra from the burning wheat straw particles showed that the emission was mainly originated from CH, C2 , Na and K chemiluminescence, and thermal radiation from soot and char burning particles. The ICCD images show that the emission from excited CH, C2, Na and K is initially detected almost at the same time, the burning of the soot particles initiates soon after the ignition, and the char particles experience ignition after the extinction of the homogeneous combustion. During the volatiles combustion stage, the temporal evolution of the normalized emission intensity of the excited CH, C2, atomic sodium and atomic potassium is quite similar; during the char oxidation stage, however, the decrease of the emission intensity of the excited atomic sodium and potassium is delayed in relation to the decrease in the emission intensity of CH and C2 because of the continuous release of atomic sodium and potassium from the burning char particles.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Biomass, Chemiluminescence, Single particle combustion, Temporally and resolved images, Wheat straw
in
Fuel
volume
224
pages
8 pages
publisher
Elsevier
external identifiers
  • scopus:85044048032
ISSN
0016-2361
DOI
10.1016/j.fuel.2018.03.101
language
English
LU publication?
yes
id
f76d559f-3cdd-4ba4-a72f-f54bb330826f
date added to LUP
2018-04-03 12:20:35
date last changed
2019-01-06 13:49:35
@article{f76d559f-3cdd-4ba4-a72f-f54bb330826f,
  abstract     = {<p>This work focuses into the combustion behaviour of single wheat straw particles with the aim of providing a quantitative description of the particle burning process from ignition to the early stages of the char oxidation. The single particles, in the size range 224–250 µm, were injected upward into a confined region with hot combustion products, produced by a flat flame McKenna burner, with a mean temperature of 1550 K and a mean dry O<sub>2</sub> concentration of 6.5 vol%. Spectral emission data and temporally resolved images of the single burning particles were obtained with a spectrometer and an ICCD camera, respectively. To obtain spectrally resolved images the camera was equipped with different band-pass filters. Overall, the results demonstrate the ability of the present experimental setup and associated optical diagnostics to gather quantitative information of the combustion process of single pulverized solid fuel particles. The emission spectra from the burning wheat straw particles showed that the emission was mainly originated from CH<sup>∗</sup>, C<sub>2</sub> <sup>∗</sup>, Na<sup>∗</sup> and K<sup>∗</sup> chemiluminescence, and thermal radiation from soot and char burning particles. The ICCD images show that the emission from excited CH, C<sub>2</sub>, Na and K is initially detected almost at the same time, the burning of the soot particles initiates soon after the ignition, and the char particles experience ignition after the extinction of the homogeneous combustion. During the volatiles combustion stage, the temporal evolution of the normalized emission intensity of the excited CH, C<sub>2</sub>, atomic sodium and atomic potassium is quite similar; during the char oxidation stage, however, the decrease of the emission intensity of the excited atomic sodium and potassium is delayed in relation to the decrease in the emission intensity of CH and C<sub>2</sub> because of the continuous release of atomic sodium and potassium from the burning char particles.</p>},
  author       = {Weng, Wubin and Costa, Mário and Li, Zhongshan and Aldén, Marcus},
  issn         = {0016-2361},
  keyword      = {Biomass,Chemiluminescence,Single particle combustion,Temporally and resolved images,Wheat straw},
  language     = {eng},
  month        = {07},
  pages        = {434--441},
  publisher    = {Elsevier},
  series       = {Fuel},
  title        = {Temporally and spectrally resolved images of single burning pulverized wheat straw particles},
  url          = {http://dx.doi.org/10.1016/j.fuel.2018.03.101},
  volume       = {224},
  year         = {2018},
}