Numerical simulation of ignition mode and ignition delay time of pulverized biomass particles
(2019) In Combustion and Flame 206. p.400-410- Abstract
In this paper, numerical simulations were carried out to identify the mode of ignition and ignition delay time of pulverized biomass particles in hot flue gas produced by a methane/air flame. In the experiments, it was observed that for most biomass residues the dominant combustion mode was the staged gas-phase ignition in the surrounding gas followed by surface ignition at the char surface. There were some exceptions to this general trend, e.g. wheat straw particles, which ignited at the surface of the particle under some temperature conditions. Moreover, temporally and spectrally resolved images of the single burning particles were obtained in the experiments and CH* chemiluminescence at different stages of biomass conversion was... (More)
In this paper, numerical simulations were carried out to identify the mode of ignition and ignition delay time of pulverized biomass particles in hot flue gas produced by a methane/air flame. In the experiments, it was observed that for most biomass residues the dominant combustion mode was the staged gas-phase ignition in the surrounding gas followed by surface ignition at the char surface. There were some exceptions to this general trend, e.g. wheat straw particles, which ignited at the surface of the particle under some temperature conditions. Moreover, temporally and spectrally resolved images of the single burning particles were obtained in the experiments and CH* chemiluminescence at different stages of biomass conversion was recorded. In this study, by means of a detailed numerical model for conversion of biomass particles and employing detailed gas chemistry mechanism, the ignition mode and ignition delay time of the particles are studied. The model is able to distinguish between different ignition modes of the particles in agreement with the experimental data. The underlying physics behind shifting ignition mode from homogeneous ignition to heterogeneous ignition for wheat straw are discussed. The ignition delay times for different biomass sources at different conditions are calculated and the results are in good agreement with the experimental data. Apart from the detailed model, CFD simulations are performed to assess the flow and combustion process (temperature, O2 concentration and velocity difference between the ambient gas and the particle) around the particle. The CFD results show similar trends compared with the CH* chemiluminescence from the particle at different times during the devolatilization stage.
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- author
- Fatehi, Hesameddin LU ; Weng, Wubin LU ; Costa, Mário ; Li, Zhongshan LU ; Rabaçal, Miriam ; Aldén, Marcus LU and Bai, Xue Song LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Combustion, Ignition mode, Numerical simulation, Pulverized biomass
- in
- Combustion and Flame
- volume
- 206
- pages
- 11 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85066093045
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2019.05.020
- language
- English
- LU publication?
- yes
- id
- 1d71b3c5-ce82-4c57-8623-239adf2922a5
- date added to LUP
- 2019-06-11 09:39:47
- date last changed
- 2022-04-26 01:14:03
@article{1d71b3c5-ce82-4c57-8623-239adf2922a5,
abstract = {{<p>In this paper, numerical simulations were carried out to identify the mode of ignition and ignition delay time of pulverized biomass particles in hot flue gas produced by a methane/air flame. In the experiments, it was observed that for most biomass residues the dominant combustion mode was the staged gas-phase ignition in the surrounding gas followed by surface ignition at the char surface. There were some exceptions to this general trend, e.g. wheat straw particles, which ignited at the surface of the particle under some temperature conditions. Moreover, temporally and spectrally resolved images of the single burning particles were obtained in the experiments and CH* chemiluminescence at different stages of biomass conversion was recorded. In this study, by means of a detailed numerical model for conversion of biomass particles and employing detailed gas chemistry mechanism, the ignition mode and ignition delay time of the particles are studied. The model is able to distinguish between different ignition modes of the particles in agreement with the experimental data. The underlying physics behind shifting ignition mode from homogeneous ignition to heterogeneous ignition for wheat straw are discussed. The ignition delay times for different biomass sources at different conditions are calculated and the results are in good agreement with the experimental data. Apart from the detailed model, CFD simulations are performed to assess the flow and combustion process (temperature, O<sub>2</sub> concentration and velocity difference between the ambient gas and the particle) around the particle. The CFD results show similar trends compared with the CH* chemiluminescence from the particle at different times during the devolatilization stage.</p>}},
author = {{Fatehi, Hesameddin and Weng, Wubin and Costa, Mário and Li, Zhongshan and Rabaçal, Miriam and Aldén, Marcus and Bai, Xue Song}},
issn = {{0010-2180}},
keywords = {{Combustion; Ignition mode; Numerical simulation; Pulverized biomass}},
language = {{eng}},
pages = {{400--410}},
publisher = {{Elsevier}},
series = {{Combustion and Flame}},
title = {{Numerical simulation of ignition mode and ignition delay time of pulverized biomass particles}},
url = {{http://dx.doi.org/10.1016/j.combustflame.2019.05.020}},
doi = {{10.1016/j.combustflame.2019.05.020}},
volume = {{206}},
year = {{2019}},
}