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Prediction of cavity growth rate during underground coal gasification using multiple regression analysis 被引量:8
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作者 Mehdi Najafi Seyed Mohammad Esmaiel Jalali +1 位作者 Reza KhaloKakaie Farrokh Forouhandeh 《International Journal of Coal Science & Technology》 EI 2015年第4期318-324,共7页
During underground coal gasification (UCG), whereby coal is converted to syngas in situ, a cavity is formed in the coal seam. The cavity growth rate (CGR) or the moving rate of the gasification face is affected by... During underground coal gasification (UCG), whereby coal is converted to syngas in situ, a cavity is formed in the coal seam. The cavity growth rate (CGR) or the moving rate of the gasification face is affected by controllable (operation pressure, gasification time, geometry of UCG panel) and uncontrollable (coal seam properties) factors. The CGR is usually predicted by mathematical models and laboratory experiments, which are time consuming, cumbersome and expensive. In this paper, a new simple model for CGR is developed using non-linear regression analysis, based on data from 1 l UCG field trials. The empirical model compares satisfactorily with Perkins model and can reliably predict CGR. 展开更多
关键词 Underground coal gasification (UCG) - Cavity growth rate . Multiple regression analysis ~ Empirical model
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Study on the Fissure Rate in the Roof Strata of Excavated Coal Seams
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作者 ZHANG Fawang CHEN Li +4 位作者 YAO Hongchao HAN Zhantao QIAN Long CHEN Liang JIANG Chengchao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第6期2090-2090,共1页
In the past decades,the intense excavation of coal resources in China has induced a series of severe waterrelated disasters or problems,such as water burst accidents,severe groundwater depletion and contamination.All ... In the past decades,the intense excavation of coal resources in China has induced a series of severe waterrelated disasters or problems,such as water burst accidents,severe groundwater depletion and contamination.All of these problems were caused by the structural changes of roof rocks or bed rocks induced by coal excavation.The structure of collapsed roof rocks is generally classified into three zones:falling zone. 展开更多
关键词 Study on the Fissure rate in the Roof Strata of Excavated Coal Seams
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Application of coal mine roof rating in Chinese coal mines 被引量:4
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作者 Wang Yongyin Taheri Abbas Xu Xianbi 《International Journal of Mining Science and Technology》 EI CSCD 2018年第3期491-497,共7页
The coal mine roof rating(CMRR) is a measure of roof quality or structure competency for bedded roof types typically of underground coal mines. The CMRR has been used widely in the US, South Africa,Canada and Australi... The coal mine roof rating(CMRR) is a measure of roof quality or structure competency for bedded roof types typically of underground coal mines. The CMRR has been used widely in the US, South Africa,Canada and Australia. In order to investigate the application of the CMRR system in Chinese coal mines,two coal mines in China located in Panjiang Coal Field in Guizhou Province were investigated. Field data were collected which is required to calculate the CMRR value based on underground exposure. The CMRR values of 11 locations in two coal mines were calculated. The investigations demonstrated that the chance of mine roof failure is very low if the CMRR value is more than 50, given adequate support is installed in mine. It was found that the CMRR guideline are useful to preliminarily investigate stability in Panjiang Coal Field mines. 展开更多
关键词 Coal mine roof rating Underground mine Roof stability Panjiang coal field
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Application of the coal mine floor rating(CMFR)to assess the floor stability in a Central Appalachian Coal Mine 被引量:1
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作者 Sena Cicek Ihsan Berk Tulu +2 位作者 Mark Van Dyke Ted Klemetti Joe Wickline 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第1期83-89,共7页
Estimating the overall floor stability in a coal mine using deterministic methods which require complex engineering properties of floor strata is desirable,but generally it is impractical due to the difficulty of gath... Estimating the overall floor stability in a coal mine using deterministic methods which require complex engineering properties of floor strata is desirable,but generally it is impractical due to the difficulty of gathering essential input data.However,applying a quantitative methodology to describe floor quality with a single number provides a practical estimate for preliminary assessment of floor stability.The coal mine floor rating(CMFR)system,developed by the University of New South Wales(UNSW),is a rockmass classification system that provides an indicator for the competence of floor strata.The most significant components of the CMFR are uniaxial compressive strength and discontinuity intensity of floor strata.In addition to the competence of the floor,depth of cover and stress notch angle are input parameters used to assess the preliminary floor stability.In this study,CMFR methodology was applied to a Central Appalachian Coal Mine that intermittently experienced floor heave.Exploratory drill core data,overburden maps,and mine plans were utilized for the study.Additionally,qualitative data(failure/non-failure)on floor conditions of the mine entries near the core holes was collected and analyzed so that the floor quality and its relation to entry stability could be estimated by statistical methods.It was found that the current CMFR classification system is not directly applicable in assessing the floor stability of the Central Appalachian Coal Mine.In order to extend the applicability of the CMFR classification system,the methodology was modified.A calculation procedure of one of the CMFR classification system’s components,the horizontal stress rating(HSR),was changed and new parameters were added to the HSR. 展开更多
关键词 Rock mass classification Coal mine floor rating(CMFR) Floor heave Floor failure Buckling failure mechanism
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Experimental research on Phanerochaete chrysosporium as coal microbial flocculant 被引量:10
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作者 Zhang Dongchen Hou Zhixiang +1 位作者 Liu Zhiyong Wang Tao 《International Journal of Mining Science and Technology》 SCIE EI 2013年第4期515-518,共4页
The flocculation effect of the Phanerochaete chrysosporium on the coal slurry were studied by orthogonal experimental method in this study.The results of research show that the P.chrysosporium has a good effect on flo... The flocculation effect of the Phanerochaete chrysosporium on the coal slurry were studied by orthogonal experimental method in this study.The results of research show that the P.chrysosporium has a good effect on flocculating coal slurry.The optimum combination of the experimental is the P.chrysosporium,which is cultured in 2 days,mixed with 2 mL coagulant and 2 mL broth.The flocculant is a broken liquid with pH value of 6.The hightest flocculation ratio is 93.5%.The result of FTIR shows that the biological extraction of P.chrysosporium contains a lot of acidic polysaccharides that has the effect on flocculation.Microbial flocculant molecules and particles of coal slurry could be flocculated by‘‘absorption bridge’’. 展开更多
关键词 Coal slurry Microbial flocculant Phanerochaete chrysosporium Flocculation rate
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Water protection in the western semiarid coal mining regions of China: A case study 被引量:5
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作者 Huang Hanfu Wang Changshen +1 位作者 Bai Haibo Wang Zihe 《International Journal of Mining Science and Technology》 SCIE EI 2012年第5期719-723,共5页
The coal industry in China has been moving from the semiarid eastern to the drier western regions since the beginning of this century.Water protection is of the utmost concern for coal mining in these regions.Lu'a... The coal industry in China has been moving from the semiarid eastern to the drier western regions since the beginning of this century.Water protection is of the utmost concern for coal mining in these regions.Lu'an,as one of the state coal mining bases in China,has been seeing increasingly heavier pressure for the protection of water resources.This article considers Lu'an as an example and describes the ways these concerns may be alleviated.High mine-water utilization rates have effectively reduced wasting of water and,consequently,have reduced water demand.Using the top layers of the Ordavician as aquifuge barriers can prevent floor karst water inrush into the longwall face and can protect the regional Ordovician karst water resources at the same time.The strength of the overlying Quaternary clay can protect against roof collapse and has successfully preserved the Quaternary porous water resource. 展开更多
关键词 Water-protection Coal mining Mine water utilization rate Aquifuge barrier Arid region
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Numerical simulation of coal wall cutting and lump coal formation in a fully mechanized mining face
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作者 Yong Yuan Shengzhi Wang +1 位作者 Wenmiao Wang Cheng Zhu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第6期1371-1383,共13页
It is difficult to accurately calculate the lump coal rate in a fully mechanized mining face.Therefore,a numerical simulation of the coal wall cutting process,which revealed the crack expansion,development,evolution i... It is difficult to accurately calculate the lump coal rate in a fully mechanized mining face.Therefore,a numerical simulation of the coal wall cutting process,which revealed the crack expansion,development,evolution in the coal body and the corresponding lump coal formation mechanism,was performed in PFC2D.Moreover,a correlation was established between the cutting force and lump coal formation,and a statistical analysis method was proposed to determine the lump coal rate.The following conclusions are drawn from the results:(1)Based on a soft ball model,a coal wall cutting model is established.By setting the roller parameters based on linear bonding and simulating the roller cutting process of the coal body,the coal wall cutting process is effectively simulated,and accurate lump coal rate statistics are provided.(2)Under the cutting stress,the coal body in the working face underwent three stages—microfracture generation,fracture expansion,and fracture penetration—to form lump coal,in which the fracture direction is orthogonal to the cutting pressure chain.Within a certain range from the roller,as the cutting depth of the roller increased,the number of new fractures in the coal body first increases and then stabilizes.(3)Under the cutting stress,the fractured coal body is locally compressed,thereby forming a compact core.The formation and destruction of the compact core causes fluctuations in the cutting force.The fluctuation amplitude is positively related to the coal mass.(4)Because the simulation does not consider secondary damage in the coal,the simulated lump coal rate is larger than the actual lump coal rate in the working face;this deviation is mainly concentrated in large lump coal with a diameter greater than 300 mm. 展开更多
关键词 Fully mechanized face Lump coal rate Fracture evolution Cutting force Particle flow simulation
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Preliminary rib support requirements for solid coal ribs using a coal pillar rib rating(CPRR)
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作者 Khaled Mohamed Mark Van Dyke +2 位作者 Gamal Rashed Morgan MSears Robert Kimutis 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第1期15-22,共8页
Researchers from the National Institute for Occupational Safety and Health(NIOSH)are developing a coal pillar rib rating(CPRR)technique to measure the integrity of coal ribs.The CPRR characterizes the rib composition ... Researchers from the National Institute for Occupational Safety and Health(NIOSH)are developing a coal pillar rib rating(CPRR)technique to measure the integrity of coal ribs.The CPRR characterizes the rib composition and evaluates its impact on the inherent stability of the coal ribs.The CPRR utilizes four parameters:rib homogeneity,bedding condition,face cleat orientation with respect to entry direction,and rib height.All these parameters are measurable in the field.A rib data collecting procedure and a simple sheet to calculate the CPRR were developed.The developed CPRR can be used as a rib quality mapping tool in underground coal mines and to determine the potential of local rib instabilities and support requirements associated with overburden depth.CPRR calculations were conducted for 22 surveyed solid coal ribs,mainly composed of coal units.Based on this study,the rib performance was classified into four categories.A preliminary minimum primary rib support density(PRSD)line was obtained from these surveyed cases.Two sample cases are presented that illustrate the data collection form and CPRR calculations. 展开更多
关键词 Coal rib stability Rib support design Coal pillar rib rating Rib quality mapping CPRR Coal classification
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RESEARCH ON THE QUALITY PRICE RATIO OF COKING COAL
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作者 陶树人 王永君 《Journal of China University of Mining and Technology》 1994年第2期47-63,共17页
If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of me... If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of metallurgical enterprises. This paper propose the principles and mathematicmodel for determination aseortment party of clean cokingcoal and its quality difference of ash content in clean coking coal in order to urge wasbenes into producing superior clean coking cleal whichis under condition of consideration both interest waskeries and interest metallurgicai industry. It canbe used as a method in theory to make price strategies under condition of socialism maket economicfor washeries of clean coking coal 展开更多
关键词 assortment price parity of clean coking coal quality difference of ash content in clean coking coal Output rate of clean coking coal
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Modeling of coal consumption rate based on wavelet neural network
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作者 Xiaoqiang Wen Shuguang Jian 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2017年第3期78-92,共15页
In this paper,two wavelet neural network(WNN)frames which depend on Morlet wavelet function and Gaussian wavelet function were established.In order to improve the efficiency of model training,the momentum term was app... In this paper,two wavelet neural network(WNN)frames which depend on Morlet wavelet function and Gaussian wavelet function were established.In order to improve the efficiency of model training,the momentum term was applied to modify the weights and thresholds,and the output of the network was summed up by function transformation of output layer nodes.When the Gaussian Wavelet Neural Networks(GWNN)and Morlet Wavelet Neural Networks(MWNN)were applied to coal consumption rate(CCR)estimation in a thermal power plant,the results confirmed their potency in function approximation.In addition,the influence of learning rate on the models was also discussed through the orthogonal experiment. 展开更多
关键词 Wavelet neural network Morlet wavelet function Gaussian wavelet function ESTIMATION coal consumption rate
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Energy conservation in China's coal-fired power industry by installing advanced units and organized phasing out backward production 被引量:1
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作者 Weiliang WANG Junfu LYU +3 位作者 Zheng LI Hai ZHANG Guangxi YUE Weidou NI 《Frontiers in Energy》 SCIE CSCD 2019年第4期798-807,共10页
Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conse... Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on. 展开更多
关键词 coal-fired power energy conservation net coal consumption rate new installation phasing out backward production unit capacity structure
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