A rapid method for determining the R70 self-heating rate of coal

Qi, Xuyao; Xin, Haihui; Wang, Biao; Qi, Guansheng

doi:10.1016/j.tca.2013.08.008

Cited by 43 publications

(17 citation statements)

References 34 publications

(46 reference statements)

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“…It has been demonstrated that the process of coal spontaneous combustion is accelerated when the ambient temperature is higher than coal temperature [24]. The inhibition performance of the prepared foams was investigated by a self-designed experiment system, which can simulate the coal acceleration combustion process.…”

Section: Examination Of the Cpt And Co-temperature Evolutionmentioning

confidence: 99%

“…Coal acceleration combustion process is in a pure copper vessel with high thermal conductivity. The statistics has shown that the spontaneous combustion of coal usually occurs under air atmosphere or low concentration oxygen atmosphere [24]. The preheated dry air instead of pure oxygen was used as gas atmosphere in the testing process for more practically simulating the coal acceleration combustion process.…”

Section: Examination Of the Cpt And Co-temperature Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Qin

Jia

Lü

et al. 2015

Fuel

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Section: Examination Of the Cpt And Co-temperature Evolutionmentioning

confidence: 99%

Section: Examination Of the Cpt And Co-temperature Evolutionmentioning

confidence: 99%

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Qin

Jia

Lü

et al. 2015

Fuel

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“…China is the world's leading energy consumer, with coal as its primary energy source, accounting for 76% and 69% of the total primary energy production and consumption, respectively . Statistics show that the number of coalmines at depths below 1000 m accounts for approximately 53% of all coalmines in China, and the number of high gas mines is approximately 50%, making it difficult to prevent gas accidents and disasters . The mining of coal resources in deeper strata has changed significantly, leading to higher in situ stress, coal seam temperature, karst water pressure, and more complex mining conditions.…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional characterization of open and closed coal nanopores based on a multi‐scale analysis including CO₂ adsorption, mercury intrusion, low‐temperature nitrogen adsorption, and small‐angle X‐ray scattering

Nie

Lun

Wang

et al. 2020

Energy Science & Engineering

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Coal seams in China have poor permeability and a complex pore structure, leading to a low gas extraction efficiency. Studying the pore structure of different metamorphic degrees of coal by using modern technological methods and employing appropriate pumping measures for different pore structures can improve the gas extraction efficiency. In this study, the pore sizes of three coal samples with different metamorphic grades were measured at different pore scales through CO 2 adsorption, nitrogen adsorption, small-angle X-ray scattering, and mercury pressure methods. The pore structure was three-dimensionally reconstructed using the lattice Boltzmann methodbased quartet structure generation set algorithm. The optimum pore size measurements performed using the CO 2 adsorption, nitrogen adsorption, small-angle X-ray scattering, and mercury pressure methods were in the ranges of 0.3-2, 1.7-300, 1-50, and 7.5-11 000 nm, respectively; this demonstrates that the structure of a full-scale coal model cannot be accurately tested using a single technique. The pore structure varies depending on the metamorphic degree of the coal; therefore, coal metamorphism should be considered for effective gas extraction. K E Y W O R D S 3D reconstruction, degree of coal metamorphism, multi-scale analysis, pore structure | 2087 NIE Et al. | 2099 NIE Et al.31. Perret J, Prasher SO, Kantzas A, Langford CH. Three-dimensional quantification of macropore networks in undisturbed soil cores. Three-dimensional characterization of open and closed coal nanopores based on a multi-scale analysis including CO 2 adsorption, mercury intrusion, low-temperature nitrogen adsorption, and small-angle X-ray scattering.

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“…Li et al [15; 16] tested the heat release intensity at low temperature and the shortest ignition time of coal spontaneous combustion with the hot-wire method. Chen and Chong [17], Sensogut and Cinar [18], and Wang et al [19][20][21] in succession proposed the Crossing-Point Temperature (CPT) method within various experimental systems to investigate heating and oxidation characteristics leading to spontaneous combustion of different kinds of coal. In addition some large scale tests were conducted by Deng et al [22] who constructed a 15-tone experimental furnace of coal spontaneous combustion to analyze the variations in temperature, so called index-gas ratios, oxygen consumption rate, heat intensity and establish the corresponding relationship between index-gas ratios and coal temperature.…”

Section: Introductionmentioning

confidence: 99%

Spontaneous combustion coal parameters for the Crossing-Point Temperature (CPT) method in a Temperature–Programmed System (TPS)

Wang

Tian

et al. 2017

Fire Safety Journal

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Coal fires originate from coal spontaneous combustion caused by oxidation starting even at low temperatures. In order to evaluate the heating and oxidation of coal placed inside a container, a Temperature-Programmed System (TPS) is used under various flow and oxidation conditions for temperatures ranging from 40 to 250 o C. As the coal samples are heated in the container within the TPS, the concentration histories of the gaseous products are measured as well as the temperature history at the center of the container. The Crossing-point Temperature (CPT) is the temperature (temperature and corresponding time) at which the increasing coal temperature is equal to the increasing oven temperature within the TPS. We have developed energy and oxygen mass conservation equations for the coal pile in a container inside the TPS oven assuming uniform conditions for temperature and oxygen concentrations, both assumptions partially justified because the heating rate in the oven is very low (1 o C/min). By subtracting the convective heat from the thermal inertia of the coal pile in the energy equation, we have obtained from the experimental data the heat owing to oxygen reaction or moisture evaporation. From the oxygen conservation and measurements, we have determined apparent activation energy and pre-exponential factor for oxidation assuming that oxidation is proportional to oxygen concentration. This information is useful for the mathematical modelling of oxidation and heating in the present experiments. Subsequently, the energy and mass conservation equations were solved after being transformed to non-dimensional form, which shows that four dimensionless parameters control the heating of coal in the present experiments. Only three of these parameters are examined in detail, namely a dimensionless flow time, a heat release parameter B, and a Damkohler number Da whereas a moisture parameter is discussed qualitatively. Based on the present analysis and data, four stages are identified: (I) initial heating with essentially no reaction or evaporation, (II) evaporation period with essentially no reaction, (III) an unsteady accelerated oxidation period during which crossover may occur and (IV) a heating late period where all the oxygen reacts inside the container.

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A rapid method for determining the R70 self-heating rate of coal

Cited by 43 publications

References 34 publications

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Three‐dimensional characterization of open and closed coal nanopores based on a multi‐scale analysis including CO₂ adsorption, mercury intrusion, low‐temperature nitrogen adsorption, and small‐angle X‐ray scattering

Spontaneous combustion coal parameters for the Crossing-Point Temperature (CPT) method in a Temperature–Programmed System (TPS)

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A rapid method for determining the R70 self-heating rate of coal

Cited by 43 publications

References 34 publications

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics

Three‐dimensional characterization of open and closed coal nanopores based on a multi‐scale analysis including CO2 adsorption, mercury intrusion, low‐temperature nitrogen adsorption, and small‐angle X‐ray scattering

Spontaneous combustion coal parameters for the Crossing-Point Temperature (CPT) method in a Temperature–Programmed System (TPS)

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Three‐dimensional characterization of open and closed coal nanopores based on a multi‐scale analysis including CO₂ adsorption, mercury intrusion, low‐temperature nitrogen adsorption, and small‐angle X‐ray scattering