Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller
Само за регистроване кориснике
2022
Конференцијски прилог (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт
Coal preparation system in case of firing lignite at thermal power plant is mainly consisted of high speed impact mills (hammer or fan mills) designed to perform efficient milling and drying of raw coal in order to significantly reduce moisture content and median diameter of particles leaving milling facility. Modelling of such complex rotating two-phase flow includes processes of mass, impulse and heat exchange between phases as well as interaction of coal particles with flow domain boundaries. In general, on the basis of performed researches, it can be stated that dissolution of single particle caused by impact on solid surface depends on intensity of cohesion forces inside particle structure and relative velocity of particle in respect to surface during contact. The aim of this part of research is to identify conditions under which contacts between solid phase and rotating impact plates mostly occur. In order to observe coal particles movement CFD calculations of two-phase flow for ...the geometry model of operated fan mill within TPP “Nikola Tesla”, Unit B, have been performed. Two-phase flow has been treated by use of CFD-DPM approach. Inlet boundary conditions has been set according to the measurements performed on concerned fan mill. Breakage phenomena has not been considered while contacts between solid phase and flow domain boundaries have been modelled by use of hard sphere model. Restitution coefficients has been adjusted so the movement of solid phase corresponds to the wearing pattern of impact plates. After performed calculations pattern of solid phase movement has been examined. Zones with lower and higher solid phase concentration in flow domain has been detected. Relative impact angles and relative impact velocities of coal particles in respect to the rotating impact plates during contact of these two entities has been identified. Additionally, kinetics of drying process used in calculations has been evaluated by use of measured moisture content in coal dust at milling plant outlet. Based on results of this study in next phase of research identification of coal particles breakage function in mill impeller will be performed. Given conclusions in this paper may be of importance for considering mill geometry modification for the purpose of increasing overall milling operating efficiency.
Кључне речи:
two-phase flow / fan mill / coal particles / coal drying / impact millingИзвор:
Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems, 2022Издавач:
- Faculty of Mechanical Engineering and Naval Architecture, Zagreb
Финансирање / пројекти:
- Повећање енергетске и еколошке ефикасности процеса у ложишту за угљени прах и оптимизација излазне грејне површине енергетског парног котла применом сопствених софтверских алата (RS-MESTD-Technological Development (TD or TR)-33018)
Колекције
Институција/група
Mašinski fakultetTY - CONF AU - Stamenković, Ognjen AU - Stupar, Goran AU - Tucaković, Dragan PY - 2022 UR - https://machinery.mas.bg.ac.rs/handle/123456789/6164 AB - Coal preparation system in case of firing lignite at thermal power plant is mainly consisted of high speed impact mills (hammer or fan mills) designed to perform efficient milling and drying of raw coal in order to significantly reduce moisture content and median diameter of particles leaving milling facility. Modelling of such complex rotating two-phase flow includes processes of mass, impulse and heat exchange between phases as well as interaction of coal particles with flow domain boundaries. In general, on the basis of performed researches, it can be stated that dissolution of single particle caused by impact on solid surface depends on intensity of cohesion forces inside particle structure and relative velocity of particle in respect to surface during contact. The aim of this part of research is to identify conditions under which contacts between solid phase and rotating impact plates mostly occur. In order to observe coal particles movement CFD calculations of two-phase flow for the geometry model of operated fan mill within TPP “Nikola Tesla”, Unit B, have been performed. Two-phase flow has been treated by use of CFD-DPM approach. Inlet boundary conditions has been set according to the measurements performed on concerned fan mill. Breakage phenomena has not been considered while contacts between solid phase and flow domain boundaries have been modelled by use of hard sphere model. Restitution coefficients has been adjusted so the movement of solid phase corresponds to the wearing pattern of impact plates. After performed calculations pattern of solid phase movement has been examined. Zones with lower and higher solid phase concentration in flow domain has been detected. Relative impact angles and relative impact velocities of coal particles in respect to the rotating impact plates during contact of these two entities has been identified. Additionally, kinetics of drying process used in calculations has been evaluated by use of measured moisture content in coal dust at milling plant outlet. Based on results of this study in next phase of research identification of coal particles breakage function in mill impeller will be performed. Given conclusions in this paper may be of importance for considering mill geometry modification for the purpose of increasing overall milling operating efficiency. PB - Faculty of Mechanical Engineering and Naval Architecture, Zagreb C3 - Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems T1 - Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller UR - https://hdl.handle.net/21.15107/rcub_machinery_6164 ER -
@conference{ author = "Stamenković, Ognjen and Stupar, Goran and Tucaković, Dragan", year = "2022", abstract = "Coal preparation system in case of firing lignite at thermal power plant is mainly consisted of high speed impact mills (hammer or fan mills) designed to perform efficient milling and drying of raw coal in order to significantly reduce moisture content and median diameter of particles leaving milling facility. Modelling of such complex rotating two-phase flow includes processes of mass, impulse and heat exchange between phases as well as interaction of coal particles with flow domain boundaries. In general, on the basis of performed researches, it can be stated that dissolution of single particle caused by impact on solid surface depends on intensity of cohesion forces inside particle structure and relative velocity of particle in respect to surface during contact. The aim of this part of research is to identify conditions under which contacts between solid phase and rotating impact plates mostly occur. In order to observe coal particles movement CFD calculations of two-phase flow for the geometry model of operated fan mill within TPP “Nikola Tesla”, Unit B, have been performed. Two-phase flow has been treated by use of CFD-DPM approach. Inlet boundary conditions has been set according to the measurements performed on concerned fan mill. Breakage phenomena has not been considered while contacts between solid phase and flow domain boundaries have been modelled by use of hard sphere model. Restitution coefficients has been adjusted so the movement of solid phase corresponds to the wearing pattern of impact plates. After performed calculations pattern of solid phase movement has been examined. Zones with lower and higher solid phase concentration in flow domain has been detected. Relative impact angles and relative impact velocities of coal particles in respect to the rotating impact plates during contact of these two entities has been identified. Additionally, kinetics of drying process used in calculations has been evaluated by use of measured moisture content in coal dust at milling plant outlet. Based on results of this study in next phase of research identification of coal particles breakage function in mill impeller will be performed. Given conclusions in this paper may be of importance for considering mill geometry modification for the purpose of increasing overall milling operating efficiency.", publisher = "Faculty of Mechanical Engineering and Naval Architecture, Zagreb", journal = "Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems", title = "Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller", url = "https://hdl.handle.net/21.15107/rcub_machinery_6164" }
Stamenković, O., Stupar, G.,& Tucaković, D.. (2022). Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller. in Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems Faculty of Mechanical Engineering and Naval Architecture, Zagreb.. https://hdl.handle.net/21.15107/rcub_machinery_6164
Stamenković O, Stupar G, Tucaković D. Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller. in Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems. 2022;. https://hdl.handle.net/21.15107/rcub_machinery_6164 .
Stamenković, Ognjen, Stupar, Goran, Tucaković, Dragan, "Modeling Milling and Drying Process of Raw Coal in Fan Mill – Part 1: Characterization of Coal Particles Movement in Fan Mill Impeller" in Book of Abstracts of 17th Conference on Sustainable Development of Energy, Water and Environment Systems (2022), https://hdl.handle.net/21.15107/rcub_machinery_6164 .