№79-5
Numerical analysis of wall temperature in underground channel during pulverized coal combustion modeling
V. Lozynskyi1
1Dnipro University of Technology, Dnipro, Ukraine
Coll.res.pap.nat.min.univ. 2024, 79:49–62
Full text (PDF)
https://doi.org/10.33271/crpnmu/79.049
ABSTRACT
Purpose. To determine the optimal approach for evaluating the temperature characteristics of the channel wall and analyze them in numerical modeling of pulverized coal combustion.
Methods. The study was conducted using numerical modeling of the pulverized coal combustion process in a cylindrical channel 30 m long and 1 m in diameter, which is formed after auger coal mining. The Ansys Fluent software was used for modeling, applying the non-premixed combustion model and the k-ε turbulence model. Calculations were performed for time intervals of 1, 12, 24, 36, and 48 hours.
Findings. Analysis of the obtained temperature fields showed that the maximum temperature in the combustion zone increases from 1220ºC (1 hour) to 1540°C (24 hours). The process stabilizes by the 12th hour at a temperature of 1490ºC. It was found that the temperature in the channel rapidly decreases after 7–10 m from the inlet, stabilizing at 490–520 ºC. The primary cause of heat loss is the high thermal conductivity of the surrounding rocks. It was determined that the Twall parameter most accurately represents the actual temperature regime of the wall and allows for an assessment of the system’s thermal state.
The originality. For the first time, a comprehensive analysis of the temperature field dynamics of the channel wall during prolonged pulverized coal combustion in a coal seam channel was conducted. Critical zones of heat loss and temperature stabilization were identified, allowing for the justified selection of the optimal wall temperature parameter for numerical modeling. Indicators of the percentage distribution of static temperature in the channel and the temperature of the wall around the channel over time were obtained.
Practical implementation. The obtained results can be used to improve numerical modeling methodologies for underground coal combustion and co-gasification processes. The identified temperature distribution patterns enable the optimization of fuel and air supply parameters to enhance the efficiency of thermochemical conversion. The proposed approach can be applied in the design of coal seam co-gasification technologies.
Keywords: computational modeling, pulverized coal combustion, wall temperature, heat transfer, co-gasification.
References
1. Salieiev, I. (2024). Organization of processes for complex mining and processing of mineral raw materials from coal mines in the context of the concept of sustainable development. Mining of Mineral Deposits, 18(1), 54–66. https://doi.org/10.33271/mining18.01.054
2. Bondarenko, V., Salieiev, I., Kovalevska, I., Chervatiuk, V., Malashkevych, D., Shyshov, M., & Chernyak, V. (2023). A new concept for complex mining of mineral raw material resources from DTEK coal mines based on sustainable development and ESG strategy. Mining of Mineral Deposits, 17(1), 1–16. https://doi.org/10.33271/mining17.01.001
3. Williams, A., Pourkashanian, M., & Jones, J.M. (2001). Combustion of pulverised coal and biomass. Progress in energy and combustion science, 27(6), 587–610. https://doi.org/10.1016/S0360-1285(01)00004-1
4. Lozynskyi, V. (2023). Critical review of methods for intensifying the gas generation process in the reaction channel during underground coal gasification (UCG). Mining of Mineral Deposits, 17(3), 67–85. https://doi.org/10.33271/mining17.03.067
5. Lozynskyi, V., Saik, P., Petlovanyi, M., Sai, K., Malanchuk Z., & Malanchyk, Ye. (2018). Substantiation into mass and heat balance for underground coal gasification in faulting zones. Inzynieria Mineralna, 19(2), 289–300. http://doi.org/10.29227/IM-2018-02-36
6. Yelubay, M., Massakbayeva, S., Aitkaliyeva, G., & Radelyuk, I. (2021). Processing of ash and slag waste. Engineering Journal of Satbayev University, 143(6), 79–84. https://doi.org/10.51301/vest.su.2021.i6.11
7. Saik, P., & Berdnyk, M. (2022). Mathematical model and methods for solving heat-transfer problem during underground coal gasification. Mining of Mineral Deposits, 16(2), 87–94. https://doi.org/10.33271/mining16.02.087
8. Ghose, P., Sahoo, T.K., & Sahu, A.K. (2023). Pulverized coal combustion computational modeling approach: A review. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power а Energy, 237(4), 797–818. https://doi.org/10.1177/095765092211329
9. Zhong, B.J., Shi, W.W., & Fu, W.B. (2002). Effects of fuel characteristics on the NO reduction during the reburning with coals. Fuel processing technology, 79(2), 93–106. https://doi.org/10.1016/S0378-3820(02)00102-9
10. Krazinski, J.L., Buckius, R.O., & Krier, H. (1979). Coal dust flames: A review and development of a model for flame propagation. Progress in Energy and Combustion science, 5(1), 31–71. https://doi.org/10.1016/0360-1285(79)90018-2
11. Kansa, E.J., & Perlee, H.E. (1980). A transient dust-flame model: application to coal-dust flames. Combustion and Flame, 38, 17–36. https://doi.org/10.1016/0010-2180(80)90034-6
12. Lozynskyi, V. (2024). Numerical simulation of carbonaceous raw material combustion in a coal seam channel. Mining of Mineral Deposits, 18(4), 109–124. https://doi.org/10.33271/mining18.04.109
13. Sheng, C., Moghtaderi, B., Gupta, R., & Wall, T.F. (2004). A computational fluid dynamics based study of the combustion characteristics of coal blends in pulverised coal-fired furnace. Fuel, 83(11–12), 1543–1552. https://doi.org/10.1016/j.fuel.2004.02.011
14. Aliukov, S., & Osintsev, K. (2021). Mathematical modeling of coal dust screening by means of sieve analysis and coal dust combustion based on new methods of piece-linear function approximation. Applied Sciences, 11(4), 1609. https://doi.org/10.3390/app11041609
15. Shi, X., Chen, X., Zhang, Y., Zhang, Y., Guo, R., Zhao, T., & Liu, R. (2022). Numerical simulation of coal dust self–ignition and combustion under inclination conditions. Energy, 239, 122227. https://doi.org/10.1016/j.energy.2021.122227
16. Shotayeva, Ye., Ryspayeva, М., & Berezovskaya, I. (2021). Increasing the efficiency of gasoline combustion depending on the spray angle in a model combustion chamber. Engineering Journal of Satbayev University, 143(6), 53–57. https://doi.org/10.51301/vest.su.2021.i6.07
17. Lertanan, T., Podjanasatja, V., Chuchan, D., & Sukjai, Y. (2024). Investigating the Characteristics of Pulverized Coal Combustion Using Ansys Fluent: A CFD Study of a 300 kW Swirl Burner. Journal of Combustion, 2024(1), 3128387. https://doi.org/10.1155/jc/3128387
18. Zhang, J., Prationo, W., Zhang, L., & Zhang, Z. (2013). Computational fluid dynamics modeling on the air-firing and oxy-fuel combustion of dried Victorian brown coal. Energy & fuels, 27(8), 4258–4269. https://doi.org/10.1021/ef400032t
19. Marangwanda, G.T., Madyira, D.M., Chihobo, H.C., & Babarinde, T.O. (2021). Modelling co-combustion of bituminous coal and pine sawdust: thermal behaviour. Fuel Communications, 9, 100035. https://doi.org/10.1016/j.jfueco.2021.100035
20. Arasappan, Y. (2022). Mathematical Simulation of Pulverized Coal Combustion. Acta Mechanica Slovaca, 26(3), 64–69. https://doi.org/10.21496/ams.2023.008
21. Du, S., Wang, J., Yu, Y., & Zhou, Q. (2023). Coarse-grained CFD-DEM simulation of coal and biomass co-gasification process in a fluidized bed reactor: Effects of particle size distribution and operating pressure. Renewable Energy, 202, 483–498. https://doi.org/10.1016/j.renene.2022.11.073
22. Bazaluk, O., Lozynskyi, V., Falshtynskyi, V., Saik, P., Dychkovskyi, R., & Cabana, E. (2021). Experimental Studies of the Effect of Design and Technological Solutions on the Intensification of an Underground Coal Gasification Process. Energies, 14(14), 4369. https://doi.org/10.3390/en14144369
