Variation in the temperature field of rocks overlying a high-temperature cavity during underground coal gasification

Luo, Jian Ming; Wang, Lianguo; Tang, Furong; He, Yan; Zheng, Lin

doi:10.1016/j.mstc.2011.03.005

Cited by 16 publications

(11 citation statements)

References 3 publications

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“…Modern rock engineering applications such as deep geological disposal of nuclear waste (Ringwood 1985;Gibb 1999;Hökmark and Claesson 2005;Gibb et al 2008;Sanchez et al 2012), geothermal heat (especially of hot dry rock) extraction (Zhao 2000;Ghassemi and Zhou 2011;Feng et al 2012;Gelet et al 2012;Cherubini et al 2013), and underground coal gasification (Burton et al 2007;Luo et al 2011;Kempka et al 2011;Younger 2011;Nakaten et al 2014) experience high-temperature environments, where rocks generally experience high temperatures up to several hundred degrees Celsius. Consequently, rock behaviors under and after high-temperature conditions are of high interest and still a challenge to scientists and engineers of different disciplines.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Sandstones Exposed to High Temperature

et al. 2015

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Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Sandstones Exposed to High Temperature

et al. 2015

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“…Experiments conducted in Russia showed that, depending on the type of rock, due to the heating of the roof, rocks in the cave zone may be in the range of 1.33-3.8 m, and the metamorphized zone of rocks is from 0.65 m to 0.84 m [47]. Luo et al [48], based on numerical simulations, determined that the temperature of 900 • C can have a range of up to 9 m in the roof. On the other hand, Wiatowski et al 2021 [49], based on research on large samples of hard coal, found that when there is a siderite layer in the coal seam, the maximum temperature of 1200 • C occurs at a distance of 0.3 m above the gasified seam.…”

Section: Discussionmentioning

confidence: 99%

Determination of the Extent of the Rock Destruction Zones around a Gasification Channel on the Basis of Strength Tests of Sandstone and Claystone Samples Heated at High Temperatures up to 1200 °C and Exposed to Water

2021

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This article presents the results of laboratory tests regarding the influence of high temperatures on changes in the strength and structural parameters of rocks that are present in the immediate vicinity of a gasification channel. Sandstone and claystone samples were heated at 300 °C, 600 °C, 900 °C and 1200 °C. Additionally, the heated samples were placed in water for 24 h. The results of the laboratory tests were used in the numerical simulation using RS2 software. The main goal of modeling was to determine the extent of the rock destruction zone around the gasification channel for dry and wet rock masses. In the numerical simulations, three widths of the gasification channel and three ranges of high-temperature impact were modeled. On the basis of the obtained results, it was found that the extent of rock destruction, both in the roof and in the floor, is greater by several percent for a wet rock mass. For the first time, this research presents the effect of water on heated rock samples in terms of the underground coal gasification process. The results of laboratory tests and numerical simulations clearly indicate a reduction in strength, deformation and structural parameters for the temperature of 1200 °C.

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“…Kinetic and thermodynamic equilibrium models are commonly used numerical simulation models of UCG. , Most of the attention is on the composition of the produced gas (H 2 , CO, CH 4 , etc.) and the temperature distribution in the gasifier under the condition of single coal thickness. , In addition, the temperature field under the condition of single coal seam thickness is studied by means of mathematical analysis or numerical simulation, and the corresponding analytical solution is obtained. − Xin uses the physical envelope curve method to study the temperature field under fixed boundary conditions and determines the influence range of the temperature field. , However, there is a lack of lateral quantitative comparative studies of gasification parameters under various coal thickness conditions.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of the Temperature Distribution and Evolution Law of Underground Lignite Gasification

Zhou

Chen

et al. 2022

ACS Omega

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To study the temperature distribution characteristics and evolution law of underground lignite gasifiers, a three-dimensional heat conduction model of underground lignite gasification was constructed. Moreover, the effects of different coal thicknesses, advance speeds of the flame working face, and surrounding rock types on the gasifier were analyzed. The results show that with the increase in the coal thickness, the transfer range and distance of temperature in the roof, floor, and coal seam gradually increase, as does the coal quantity in the three zones. The heat loss rate of the gasifier decreased gradually with the coal seam thickness. When the advance speed of the flame working face is 0.5 m/d, the ideal gasification coal thickness range of lignite is 2.5–17.5 m. With the increase in the gasification rate, the maximum transfer distance of temperature to the roof and floor, the average temperature of the gasifier, and the coal quantity of the three zones gradually increase. Conversely, the coal thickness corresponding to the intersection of the coal quantity of the oxidation and reduction zones and the heat loss rate of the gasifier gradually decrease. When the coal seam below 2.5 m is gasified, the gasification rate can be increased appropriately. When the coal seam is above 13 m, increasing the gasification rate will make the coal quantity in the oxidation zone close to or even higher than that in the reduction zone. Regarding the surrounding rock types comprising a combination of siltstone, mudstone, sandy mudstone, and fine sandstone, the most favorable roof and floor type for underground coal gasification is the combination of fine sandstone and sandy mudstone (without considering the sealing and mechanical properties). These results provide important theoretical support for the industrialization of underground coal gasification.

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Variation in the temperature field of rocks overlying a high-temperature cavity during underground coal gasification

Cited by 16 publications

References 3 publications

Mechanical Properties of Sandstones Exposed to High Temperature

Mechanical Properties of Sandstones Exposed to High Temperature

Determination of the Extent of the Rock Destruction Zones around a Gasification Channel on the Basis of Strength Tests of Sandstone and Claystone Samples Heated at High Temperatures up to 1200 °C and Exposed to Water

Numerical Simulation of the Temperature Distribution and Evolution Law of Underground Lignite Gasification

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