An innovative method to calculate oxygen consumption rate

Abstract

Based on heat and mass transfer characteristics of spontaneous combustion of coal, Arrhenius equation and the Ranz-Marshall correlation, a novel approach was proposed in this paper to estimate oxygen consumption rate of self-ignition of coal at high temperature. Compared with the conventional methods, this approach involves not only kinetic properties of self-ignition of coal and temperature, but also the ambient air flow characteristics and diameter of coal particle. To testify the proposed approach, oxygen consumption rates at high temperature were measured by the programmable isothermal oven experiments. Comparisons between experimental and theoretical results indicate that the rates of oxygen depletion calculated by the proposed approach agree well with those measured from laboratory-scale experiments, which further validates the proposed approach.

Keywords

self-ignition of coal / oxygen consumption rate / oxygen transport / timescale / critical temperature / programmable isothermal oven experiment

References

[1] YangF-q, WuC, LiZ-jun. Spontaneous combustion tendency of fresh and pre-oxidized sulfide ores [J]. Journal of Central South University, 2014, 21(2): 715-719

[2] YangF-q, WuChao. Mechanism of mechanical activation for spontaneous combustion of sulfide minerals [J]. Transactions of Nonferrous Metals Society of China, 2013, 23(1): 276-282

[3] ZhangJ-z, KuenzerC. Thermal surface characteristics of coal fires 1: Results of in-situ measurements [J]. Journal of Applied Geophysics, 2007, 63(3): 117-134

[4] ZhuH-q, SongZ-y, TanB, HaoY-ze. Numerical investigation and theoretical prediction of self-ignition characteristics of coarse coal stockpiles [J]. Journal of Loss Prevention in the Process Industries, 2013, 26(1): 236-244

[5] TarabaB, MichalecZ. Effect of longwall face advance rate on spontaneous heating process in the gob area—CFD modelling [J]. Fuel, 2011, 90(8): 2790-2797

[6] YuanL-m, SmithA C. The effect of ventilation on spontaneous heating of coal [J]. Journal of Loss Prevention in the Process Industries, 2012, 25(1): 131-137

[7] QinY-p, LiuW, YangC, FanZ-z, WangL-l, JiaG-wei. Experimental study on oxygen consumption rate of residual coal in goaf [J]. Safety Science, 2012, 50(4): 787-791

[8] YuanL-m, SmithA C. Numerical study on effects of coal properties on spontaneous heating in longwall gob areas [J]. Fuel, 2008, 87(15): 3409-3419

[9] AkgunF, EssenhighR H. Self-ignition characteristics of coal stockpiles: Theoretical prediction from a two-dimensional unsteady-state model [J]. Fuel, 2001, 80(3): 409-415

[10] EjlaliA, AminossadatiS M, HoomanK, BeamishB B. A new criterion to design reactive coal stockpiles [J]. International Communications in Heat and Mass Transfer, 2009, 36(7): 669-673

[11] EjlaliA, MeeD J, HoomanK, BeamishB B. Numerical modelling of the self-heating process of a wet porous medium [J]. International Journal of Heat and Mass Transfer, 2011, 54(25): 5201-5206

[12] KrishnaswamyS, AgarwalP K, GunnR D. Low-temperature oxidation of coal 3. Modelling spontaneous combustion in coal stockpiles [J]. Fuel, 1996, 75(3): 353-362

[13] KuenzerC, StracherG B. Geomorphology of coal seam fires [J]. Geomorphology, 2012, 138(1): 209-222

[14] StracherG B. Coal fires burning around the world: A global catastrophe [J]. International Journal of Coal Geology, 2004, 59(1): 1-6 2

[15] WuJ-j, LiuX-chen. Risk assessment of underground coal fire development at regional scale [J]. International Journal of Coal Geology, 2011, 86(1): 87-94

[16] VanD P, ZhangJ-z, JunW, KuenzerC, WolfK-Heinz. Assessment of the contribution of in-situ combustion of coal to greenhouse gas emission; based on a comparison of Chinese mining information to previous remote sensing estimates [J]. International Journal of Coal Geology, 2011, 86(1): 108-119

[17] RosemaA, GuanH, VeldH. Simulation of spontaneous combustion, to study the causes of coal fires in the Rujigou basin [J]. Fuel, 2001, 80(1): 7-16

[18] ZhuJ-f, HeN, LiD-ji. The relationship between oxygen consumption rate and temperature during coal spontaneous combustion [J]. Safety Science, 2012, 50(4): 842-845

[19] BeamishB B, BarakatM A, GeorgeJ D S. Adiabatic testing procedures for determining the self-heating propensity of coal and sample ageing effects [J]. Thermochimica Acta, 2000, 362(1): 79-87 2

[20] BeamishB B, BlazakD G. Relationship between ash content and R70 self-heating rate of callide coal [J]. International Journal of Coal Geology, 2005, 64(1): 126-132 2

[21] HeQ-l, WangD-ming. Comprehensive study on the rule of spontaneous combustion coal in oxidation process by TG-DTA-FTIR technology [J]. Journal of China Coal Society, 2005, 30(1): 53-57(in Chinese)

[22] KrajčiovM, JelemenskL, KišaM, MarkošJ. Model predictions on self-heating and prevention of stockpiled coals [J]. Journal of Loss Prevention in the Process Industries, 2004, 17(3): 205-216

[23] WesslingS, KesselsW, SchmidtM, KrauseU. Investigating dynamic underground coal fires by means of numerical simulation [J]. Geophysical Journal International, 2008, 172(1): 439-454

[24] FuW-biaoThe macro-general rules of coal combustion theories [M], 2003, Beijing, Tsinghua University Press(in Chinese)

[25] ChertockA, KurganovA, PetrovaG. Fast explicit operator splitting method for convection-diffusion equations [J]. International Journal for Numerical Methods in Fluids, 2009, 59(3): 309-332

[26] DuarteM, DescombesS P, TenaudC, CandelS B, MassotM. Time-space adaptive numerical methods for the simulation of combustion fronts [J]. Combustion and Flame, 2013, 160(6): 1083-1101