Influence of Ambient Temperature on the Incubation Period, and the Tendency of Coal to Ignite Spontaneously


Annotation:

Crushing coal during mining significantly increases the contact area of combustible components with atmospheric oxygen. The heat released during coal oxidation can lead to an increase in the temperature of the coal accumulation and the appearance of places of spontaneous combustion. For the timely prevention of endogenous fires, it is required to know the incubation period of spontaneous combustion, which is necessary for the coal accumulation to reach the critical temperature. Based on this parameter, the category of coal propensity to spontaneous combustion is established, and measures are developed to reduce the endogenous fire hazard. 
The known method for estimating the incubation period does not sufficiently consider the influence of the environmental parameters on coal heating. The discrepancy between the calculated and actual duration is observed for coal at a negative temperature, for example, in the mines, and the open-casts in the permafrost areas, as well as in the warehouses in winter on a significantly large territory of Russia. Studies showed that a decrease in temperature significantly reduces the rate constant of oxygen sorption by the coal, and the release of heat in the coal accumulation. The process of spontaneous combustion of coal also slows down due to additional heat losses for the phase transition of water from solid to liquid state.  
For improving the accuracy of calculating the incubation period of spontaneous combustion of coal at negative temperatures, it is proposed to consider the specific heat of melting ice, and to determine the oxygen sorption rate constant at a constant temperature from –10 to –20 ° C.
The influence of negative temperatures of coal accumulation increases the incubation period of spontaneous combustion of coal by 2–3 times allowing to reduce the cost of measures to prevent endogenous fires.

References:
1. Skochinskiy A.A., Ogievskiy V.M. Mine fires. Moscow: Izd-vo «Gornoe delo» OOO «Kimmeriyskiy tsentr», 2011. 375 p. (In Russ.).
2. Yutyaev E.P., Portola V.A., Meshkov A.A., Kharitonov I.L., Zhdanov A.N. Development of self-heating process in coal stocks under molecular diffusion of oxygen. Ugol = Coal. 2018. № 10 (1111). pp. 42–46. (In Russ.). DOI: 10.18796/0041-5790-2018-10-42-46
3. Lin Q., Wang S., Liang Y., Song S., Ren T. Analytical prediction of coal spontaneous combustion tendency: Velocity range with high possibility of self-ignition. Fuel Processing Technology. 2017. Vol. 159. pp. 38–47.
4. Deng J., Zhao J.-Y., Huang A.-C., Zhang Y.-N., Wang C.-P., Shu C.-M. Thermal behavior and microcharacterization analysis of second-oxidized coal. Journal of Thermal Analysis and Calorimetry. 2017. Vol. 127. Iss. 1. pp. 439–448. DOI: 10.1007/s10973-016-5493-8
5. Liu W., Yueping Q., Xiaobin Y., Wenqiang W., Youqiang C. Early extinguishment of spontaneous combustion of coal underground by using dry-ice’s rapid sublimation: A case study of application. Fuel. 2018. Vol. 217. pp. 544–552. DOI: 10.1016/j.fuel.2017.12.124
6. Yuan H., Restuccia F., Richter F., Rein G. A computational model to simulate self-heating ignition across scales, configurations, and coal origins. Fuel. 2019. Vol. 236. pp. 1100–1109. DOI: 10.1016/j.fuel.2018.09.065
7. Liang Y., Wang S. Prediction of coal mine goaf self-heating with fluid dynamics in porous media. Fire Safety Journal. 2017. Vol. 87. pp. 49–56. DOI: 10.1016/j.firesaf.2016.12.002
8. Portola V.A. Assessment of the effect of some factors on spontaneous coal combustion. Journal of Mining Science. 1996. Vol. 32. Iss. 3. pp. 212–218.
9. Wang J., Zhang Y., Xue S., Wu J., Tang Y., Chang L. Assessment of spontaneous combustion status of coal based on relationships between oxygen consumption and gaseous product emissions. Fuel Processing Technology. 2018. Vol. 179. pp. 60–71. DOI: 10.1016/j.fuproc.2018.06.015
10. Semenova S.A., Patrakov Y.F., Majorov A.E. Assessment of the likelihood of underground coal oxidation and self-ignition: A review. Koks i khimiya = Coke and Chemistry. 2020. № 5. pp. 12–21. (In Russ.).
11. Portola V.A. Danger of Coal Dust Self-Ignition. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2015. № 6. pp. 36–39. (In Russ.).
12. Sin S.A. The use of nitrogen to fight the spontaneous combustion of coal in the mines. Vestnik KuzGTU = Bulletin of the Kuzbass State Technical University. 2015. № 1 (107). pp. 167–171. (In Russ.).
13. Instructions for the prevention of exogenous and endogenous fire hazards at mining facilities in the coal industry: Federal rules and regulations in the field of industrial safety. Ser. 05. Iss. 61. Moscow: ZAO NTTs PB, 2021. 60 p. (In Russ.).
14. Alperovich V.Ya., Chuntu G.I., Pashkovskiy P.S., Koshovskiy B.I., Eyner F.F. Incubation period of coals spontaneous combustion. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 1973. № 9. pp. 43–45. (In Russ.).
15. Instructions for determining the incubation period of the coal spontaneous combustion: Federal rules and regulations in the field of industrial safety. Ser. 05. Iss. 38. Moscow: ZAO NTTs PB, 2013. 24 p. (In Russ.).
16. Veselovskiy V.S., Alekseeva N.D., Vinogradova L.N., Orleanskaya G.L., Terpogosova E.A. Spontaneous-combustion of industrial materials. Moscow: Nauka, 1964. 246 p. (In Russ.).
17. Veselovskiy V.S., Vinogradova L.P., Orleanskaya G.L., Terpogosova E.A., Odinokova L.V., Sukhova L.F. Forecast and prevention of endogenous fires. Moscow: Nauka, 1975. 158 p. (In Russ.).
DOI: 10.24000/0409-2961-2022-1-27-32
Year: 2022
Issue num: January
Keywords : endogenous fire spontaneous combustion of coal incubation period of spontaneous combustion oxygen sorption rate constant tendency to spontaneous-combustion coal temperature
Authors:
  • Portola V.A.
    Portola V.A.
    Dr. Sci. (Eng.), Prof., portola2@yandex.ru KuzGTU named after T.F. Gorbacheva, Kemerovo, Russia
  • Bobrovnikova A.A.
    Bobrovnikova A.A.
    Cand. Sci. (Chem.), Head of the Department T.F. Gorbachev Kuzbass State Technical University, Kemerovo, Russia
  • Protasov S.I.
    Protasov S.I.
    Cand. Sci. (Eng.), Director Innovative firm «KUZBASS-NIIOGR», Kemerovo, Russia