Mechanism of primary fragmentation of coal in fluidized bed
Abstract
In order to lay a foundation of a credible primacy fragmentation model, a theoretical analysis of the thermo-mechanical processes in a devolatilizing solid fuel particle was carried out. The devolatilization model comprises heat transfer, chemical processes of generation of gaseous products of combustion (volatiles), volatile transfer, and solid mechanic processes. A spatial and temporal analysis of the stresses within the particle showed that the radial stress is caused primarily by the pressure of generated volatiles. This stress monotonously decreases from the particle center towards the particle surface, without changing its sign. The tangential stress is caused primarily by the thermal shock. Close to the surface, it changes its sign. In the particle cross-section, the radial stress prevails close to the particle center, whilst the tangential stress is dominant in the surface region. At the points where these stresses exceed the particle tensile strength, cracks occur. Cracks exte...nd tangentially close to the surface, and radially close to the center of the particle.
Keywords:
primary fragmentation / fluidized bed / devolatilization / coalSource:
Thermal Science, 2016, 20, S125-S132Publisher:
- Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
Funding / projects:
- Fluidized bed combustion facility improvements as a step forward in developing energy efficient and environmentally sound waste combustion technology in fluidized bed combustors (RS-MESTD-Technological Development (TD or TR)-33042)
- Development and improvement of technologies for energy efficient and environmentally sound use of several types of agricultural and forest biomass and possible utilization for cogeneration (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-42011)
DOI: 10.2298/TSCI150603224P
ISSN: 0354-9836
WoS: 000378584200013
Scopus: 2-s2.0-84982867281
Collections
Institution/Community
Mašinski fakultetTY - JOUR AU - Paprika, Milijana J. AU - Komatina, Mirko AU - Mladenović, Milica R. AU - Živković, Goran AU - Dakić, Dragoljub PY - 2016 UR - https://machinery.mas.bg.ac.rs/handle/123456789/2309 AB - In order to lay a foundation of a credible primacy fragmentation model, a theoretical analysis of the thermo-mechanical processes in a devolatilizing solid fuel particle was carried out. The devolatilization model comprises heat transfer, chemical processes of generation of gaseous products of combustion (volatiles), volatile transfer, and solid mechanic processes. A spatial and temporal analysis of the stresses within the particle showed that the radial stress is caused primarily by the pressure of generated volatiles. This stress monotonously decreases from the particle center towards the particle surface, without changing its sign. The tangential stress is caused primarily by the thermal shock. Close to the surface, it changes its sign. In the particle cross-section, the radial stress prevails close to the particle center, whilst the tangential stress is dominant in the surface region. At the points where these stresses exceed the particle tensile strength, cracks occur. Cracks extend tangentially close to the surface, and radially close to the center of the particle. PB - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd T2 - Thermal Science T1 - Mechanism of primary fragmentation of coal in fluidized bed EP - S132 SP - S125 VL - 20 DO - 10.2298/TSCI150603224P ER -
@article{ author = "Paprika, Milijana J. and Komatina, Mirko and Mladenović, Milica R. and Živković, Goran and Dakić, Dragoljub", year = "2016", abstract = "In order to lay a foundation of a credible primacy fragmentation model, a theoretical analysis of the thermo-mechanical processes in a devolatilizing solid fuel particle was carried out. The devolatilization model comprises heat transfer, chemical processes of generation of gaseous products of combustion (volatiles), volatile transfer, and solid mechanic processes. A spatial and temporal analysis of the stresses within the particle showed that the radial stress is caused primarily by the pressure of generated volatiles. This stress monotonously decreases from the particle center towards the particle surface, without changing its sign. The tangential stress is caused primarily by the thermal shock. Close to the surface, it changes its sign. In the particle cross-section, the radial stress prevails close to the particle center, whilst the tangential stress is dominant in the surface region. At the points where these stresses exceed the particle tensile strength, cracks occur. Cracks extend tangentially close to the surface, and radially close to the center of the particle.", publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd", journal = "Thermal Science", title = "Mechanism of primary fragmentation of coal in fluidized bed", pages = "S132-S125", volume = "20", doi = "10.2298/TSCI150603224P" }
Paprika, M. J., Komatina, M., Mladenović, M. R., Živković, G.,& Dakić, D.. (2016). Mechanism of primary fragmentation of coal in fluidized bed. in Thermal Science Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 20, S125-S132. https://doi.org/10.2298/TSCI150603224P
Paprika MJ, Komatina M, Mladenović MR, Živković G, Dakić D. Mechanism of primary fragmentation of coal in fluidized bed. in Thermal Science. 2016;20:S125-S132. doi:10.2298/TSCI150603224P .
Paprika, Milijana J., Komatina, Mirko, Mladenović, Milica R., Živković, Goran, Dakić, Dragoljub, "Mechanism of primary fragmentation of coal in fluidized bed" in Thermal Science, 20 (2016):S125-S132, https://doi.org/10.2298/TSCI150603224P . .