A coupled model of air leakage in gas drainage and an active support sealing method for improving drainage performance

Wang, Zhiming; Sun, Yajun; Wang, Yonglong; Zhang, Junxiang; Sun, Zhidong

doi:10.1016/j.fuel.2018.10.077

Cited by 59 publications

(25 citation statements)

References 39 publications

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“…With the rapid development of mechanical manufacturing, the sealing materials in these industries are facing higher and stricter requirements, hence the preparation of novel sealing materials have become a new challenge . It is well known that polytetrafluoroethylene (PTFE) has unique properties, such as high temperature, thermal stability, and excellent chemical resistance, which is due to high bond energy of carbon‐fluorine .…”

Section: Introductionmentioning

confidence: 99%

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Kou

Pan

et al. 2019

J of Applied Polymer Sci

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To achieve polymer‐matrix composites for sealing materials with thermostability and toughness, PTFE composites filled with short glass fibers (SGFs) were hyperthermal stretched to prepare a substrate material with high thermal stability and porosity. The effects of various tensile rates on the thermal and mechanical properties and morphologies were investigated. The results revealed that the thermal stability could be improved slightly and the thermal expansion coefficient of composites increased by the tensile rate. Through observing the morphologies, tensile process produced cavities and the increased tensile rate had negligible effects on porosity, which also could be proved by density test. From mechanical properties analysis, stretched composites exhibited that the tensile strength increases first and then decreases with the increased tensile rate. Although the variation tendency of Young's modulus is similar to that of tensile strength, which is smaller than that of unstretched composite. When the tensile rate reached 50 mm·min−1, the tensile strength and Young's modulus of the stretched composites increased by 65 and 9% to maximum, respectively. Meanwhile, elongation at break and shore hardness decreased. The thermal and mechanical properties improvement could be ascribed to the strain‐induced crystallization and crystal alignment. In addition, the interplanar spacing and grain size were inversely proportional to the tensile rate. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48175.

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Section: Introductionmentioning

confidence: 99%

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Kou

Pan

et al. 2019

J of Applied Polymer Sci

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“…e surrounding rock of the roadway is deforming at a high speed. More and more serious borehole collapse and deformation are challenging gas drainage and putting forward higher requirements [26,27].…”

Section: Introductionmentioning

confidence: 99%

Research on Optimization of Key Areas of Drainage Borehole Sealing in Ultrathick Coal Seam

Guo

Xue

et al. 2021

Shock and Vibration

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Gas drainage is an important means of gas control. The influence of the key position of the sealing hole on gas drainage was studied by theoretical and numerical simulation combined with field measurement to solve low gas concentration in gas predrainage boreholes in coal mines of China. By analyzing the distribution of cracks around the boreholes and the law of air leakage and simulating the drainage effect of different sealing areas (8 m, 12 m, and 16 m), it was proposed that the key position of the sealing hole should be in the prepeak stress concentration area. According to the actual situation of Baode Mine, the sealing test scheme of different sealing areas was put forward, and the field test was carried out to obtain the key sealing area of gas predrainage boreholes in Baode Mine. Research shows that when the sealing area is 8–16 m, the average gas concentration is 63.57%, and the average pure gas flux is 0.408 m3/min. The sealing effect of this area is better, with fewer cracks, than that of the existing sealing area, effectively preventing gas leakage and increasing the gas concentration and gas scalar.

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“…However, the utilization rate of CMM in China in 2015 was only 35.3%, resulting in considerable energy loss and environmental pollution (National Energy Administration, 2016). Air leakage caused by the poor borehole sealing performance is the main cause of low gas drainage e ciency (Zheng et al, 2016, Wang et al, 2019b, Xia et al, 2014.…”

Section: Introductionmentioning

confidence: 99%

Optimal design method of sealing depth in methane drainage boreholes to realize efficient drainage

Wang

Chen

et al. 2021

Preprint

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The purpose of underground methane drainage technology is to eliminate methane disasters and enable the efficient use of coal mine methane (CMM). The sealing depth is a key factor that affects the underground methane drainage performance. In this work, the layouts of bedding and crossing boreholes were considered to analyze the stress distribution and failure characteristics of roadway surrounding rocks through a numerical simulation and field stress investigation to determine a reasonable sealing depth. The results demonstrated that the depths of the plastic zone and elastic zone in the Xutuan and Qinan coal mines were 16 m and 20 m, respectively. Borehole sealing could minimize the air leakage through the fractures around the roadway when the sealing material covered the failure and plastic zones. In addition, the field test results of CMM drainage at different sealing depths indicated that the CMM drainage efficiency increased with an increase in the sealing depth and not change when the sealing depth exceeded the plastic zone. Moreover, sealing in the high permeability roadway surrounding rock did not strongly influence the borehole sealing performance. Considering these findings, a new CMM drainage system for a specific sealing depth and length was developed, which could effectively improve the CMM drainage efficiency and prolong the high concentration CMM drainage period. The proposed approach can be a valuable quantitative analysis method to select the optimized sealing parameters for underground methane drainage, which can considerably improve the drainage and utilization rates of CMM.

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A coupled model of air leakage in gas drainage and an active support sealing method for improving drainage performance

Cited by 59 publications

References 39 publications

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Effect of tensile rates on thermal and mechanical properties of porous PTFE composites

Research on Optimization of Key Areas of Drainage Borehole Sealing in Ultrathick Coal Seam

Optimal design method of sealing depth in methane drainage boreholes to realize efficient drainage

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