2018 No. 3
Abstract：
In order to realize an accurate identification of the coal and rock interface during the cutting process of the coal shearer, the vibration signals and infrared thermal image signals of the picks during the cutting process were selected as the signals of the coal and rock identification characteristics. According to the x, y and z three directional vibration acceleration signals of the picks during the cutting process, as well as the vibration spectrum, tip infrared flash temperature value and temperature-frequency image were timely collected, the variation law between the vibration signals and infrared thermal image signals of the picks and the different coal and rock percentage specimens were analyzed. The test results showed that with the rock percentage in the specimens increased, the average value of the pick vibration acceleration would be steadily increased and the correspondent root-mean-square value of the spectrum would be steadily increased. During the cutting process of the specimens, a point flash temperature area would be occurred on the tip of the pick. During the cutting of the full rock specimens, the max flash temperature value and high temperature area scale would be larger than the cutting of the full coal specimens and the correspondent frequency of the max temperature in the temperature-frequency image would be steadily increased. The identification results of the BP neural network would be same to the actual coal and rock percentage of the test samples and could accurately indentify the coal and rock percentage of the cutting spectrum. The study results could provide the important method and means to realize the accurate identification of the coal and rock interface.
In order to realize an accurate identification of the coal and rock interface during the cutting process of the coal shearer, the vibration signals and infrared thermal image signals of the picks during the cutting process were selected as the signals of the coal and rock identification characteristics. According to the x, y and z three directional vibration acceleration signals of the picks during the cutting process, as well as the vibration spectrum, tip infrared flash temperature value and temperature-frequency image were timely collected, the variation law between the vibration signals and infrared thermal image signals of the picks and the different coal and rock percentage specimens were analyzed. The test results showed that with the rock percentage in the specimens increased, the average value of the pick vibration acceleration would be steadily increased and the correspondent root-mean-square value of the spectrum would be steadily increased. During the cutting process of the specimens, a point flash temperature area would be occurred on the tip of the pick. During the cutting of the full rock specimens, the max flash temperature value and high temperature area scale would be larger than the cutting of the full coal specimens and the correspondent frequency of the max temperature in the temperature-frequency image would be steadily increased. The identification results of the BP neural network would be same to the actual coal and rock percentage of the test samples and could accurately indentify the coal and rock percentage of the cutting spectrum. The study results could provide the important method and means to realize the accurate identification of the coal and rock interface.
Abstract：
Based on the comprehensive experiment study and the theoretical analysis on the super－critical CO2 injection in the seam at home and abroad，it was found that the super－critical CO2 injection in the seam would be affected to the material composition and the physical structure and could reconstruct the pore cracking system．The major causes could be that the super－critical CO2 injection individually would have the geochemical reaction with the minerals in the coal and the coal matrix．In the reaction system of the super－critical CO2 injection－H2O－coal and rock，the minerals in the coal would have erosion dissolution sediment．Among them，the most sensitivity would bethe carbonate minerals and then would be the feldspar and clay mineral．The sulfide mineral( pyrites) and quartz would be stable relatively．The super－critical CO2 injection would have a certain extraction role to the small molecule in the coal matrix and thus could change the molecular structure of the coal．The major factors affected to the super－critical CO2 injection－H2O－coal and rock reaction would be the coalmineral composition，macerals and coal grade，coal reservoir pressure and ground temperature condition as well as the formation water salin-ity and others．Due to the limitation of the test simulation and numerical simulation，the response mechanism of the super－critical CO2 in-jection－H2O－coal and rock geochemistry would be needed to be discussed in detail and meanwhile a real time observation and position study on the pore cracking network variation of the coal and rock would be more important．
Based on the comprehensive experiment study and the theoretical analysis on the super－critical CO2 injection in the seam at home and abroad，it was found that the super－critical CO2 injection in the seam would be affected to the material composition and the physical structure and could reconstruct the pore cracking system．The major causes could be that the super－critical CO2 injection individually would have the geochemical reaction with the minerals in the coal and the coal matrix．In the reaction system of the super－critical CO2 injection－H2O－coal and rock，the minerals in the coal would have erosion dissolution sediment．Among them，the most sensitivity would bethe carbonate minerals and then would be the feldspar and clay mineral．The sulfide mineral( pyrites) and quartz would be stable relatively．The super－critical CO2 injection would have a certain extraction role to the small molecule in the coal matrix and thus could change the molecular structure of the coal．The major factors affected to the super－critical CO2 injection－H2O－coal and rock reaction would be the coalmineral composition，macerals and coal grade，coal reservoir pressure and ground temperature condition as well as the formation water salin-ity and others．Due to the limitation of the test simulation and numerical simulation，the response mechanism of the super－critical CO2 in-jection－H2O－coal and rock geochemistry would be needed to be discussed in detail and meanwhile a real time observation and position study on the pore cracking network variation of the coal and rock would be more important．
Abstract：
In order to study the seismic response characteristics of deformed coal and improve the accuracy of using 3D seismic to predict deformed coal, the No.Ⅲ102 mining area of Luling Coal Mine was taken as an example. The amplitude characteristics of undeformed coal and deformed coal with different thickness and the characteristics of amplitude absorption attenuation in different tuning frequency were studied by using seismic forward modeling. A method of deformed coal identification based on three-dimensional seismic spectrum decomposition was proposed. The results showed that the amplitude absorption attenuation of undeformed coal and deformed coal was basically the same in the low frequency range of seismic. With the increase of tuning frequency, the difference of amplitude absorption attenuation between undeformed coal and deformed coal increased, at a certain frequency reaches the maximum and then decreased slowly. The smaller the thickness of coal, the higher tuning frequency when the amplitude absorption attenuation difference reached the maximum. In Luling Coal Mine, the conformity between the range of deformed coal development identified by spectral division method and drilling was 93%, and the conformity between conventional method and drilling was 76%. The deformed coal seismic recognition method based on spectral decomposition effectively improved the recognition accuracy of deformed coal.
In order to study the seismic response characteristics of deformed coal and improve the accuracy of using 3D seismic to predict deformed coal, the No.Ⅲ102 mining area of Luling Coal Mine was taken as an example. The amplitude characteristics of undeformed coal and deformed coal with different thickness and the characteristics of amplitude absorption attenuation in different tuning frequency were studied by using seismic forward modeling. A method of deformed coal identification based on three-dimensional seismic spectrum decomposition was proposed. The results showed that the amplitude absorption attenuation of undeformed coal and deformed coal was basically the same in the low frequency range of seismic. With the increase of tuning frequency, the difference of amplitude absorption attenuation between undeformed coal and deformed coal increased, at a certain frequency reaches the maximum and then decreased slowly. The smaller the thickness of coal, the higher tuning frequency when the amplitude absorption attenuation difference reached the maximum. In Luling Coal Mine, the conformity between the range of deformed coal development identified by spectral division method and drilling was 93%, and the conformity between conventional method and drilling was 76%. The deformed coal seismic recognition method based on spectral decomposition effectively improved the recognition accuracy of deformed coal.
Abstract：
Based on the principle of gob-side entry retaining with roof cutting and pressure releasing, the formation mechanism of roadway side wall formed by gangue was analyzed, and the motion characteristics of the roof was discussed by establishing the structure model of surrounding rock. According to the field measured data, the process of the gangue movement was divided into two stages, including rapid collapse stage and slow compaction stage, and then, the interaction relationship between the gangue and the supporting structure at each stage was clearly obtained. Besides, a control ideal, combining static and dynamic in the horizontal direction and extensible at the vertical direction to relief pressure, was put forward to lateral supporting structure base on the motion characteristics of the roof and the gangue. At last, three different control structures were proposed in view of different mining height, and the control system was established, which has been proved to be of good practicality in engineering site.
Based on the principle of gob-side entry retaining with roof cutting and pressure releasing, the formation mechanism of roadway side wall formed by gangue was analyzed, and the motion characteristics of the roof was discussed by establishing the structure model of surrounding rock. According to the field measured data, the process of the gangue movement was divided into two stages, including rapid collapse stage and slow compaction stage, and then, the interaction relationship between the gangue and the supporting structure at each stage was clearly obtained. Besides, a control ideal, combining static and dynamic in the horizontal direction and extensible at the vertical direction to relief pressure, was put forward to lateral supporting structure base on the motion characteristics of the roof and the gangue. At last, three different control structures were proposed in view of different mining height, and the control system was established, which has been proved to be of good practicality in engineering site.
Abstract：
Based on the overlying strata movement behavior under consolidated backfill mining method,the stability of support along side the gob side entry and coal wall was analyzed and then the reasonable width of the support and length of the elastic plastic zone in the coal wall were deducted.Based on Winkler elastic foundation beam theory,a beam model in gob side entry retaining under consolidated backfill mining to analyze the mechanics of immediate roof was built.The No.9301 backfill mining working face in Tangkou Coal Mine was selected as the analysis example,where the three key parameters influencing the roof subsidence in the entry were determined,i.e.the elastic foundation coefficient of the support was 50 MN/m3,the width of the support was 3 m and the elastic foundation coefficient of the backfill body in the gob is 80 MN/m3.In such condition,the roof subsidence could be controlled effectively.In the meantime,combined with the monitoring results of convergence between roof and floor in No.9301 roadway of Tangkou Coal Mine,the filed measurement showed that the maximum convergence of roof and floor was 213 mm，the surrounding rock control in the gob side entry was effective.
Based on the overlying strata movement behavior under consolidated backfill mining method,the stability of support along side the gob side entry and coal wall was analyzed and then the reasonable width of the support and length of the elastic plastic zone in the coal wall were deducted.Based on Winkler elastic foundation beam theory,a beam model in gob side entry retaining under consolidated backfill mining to analyze the mechanics of immediate roof was built.The No.9301 backfill mining working face in Tangkou Coal Mine was selected as the analysis example,where the three key parameters influencing the roof subsidence in the entry were determined,i.e.the elastic foundation coefficient of the support was 50 MN/m3,the width of the support was 3 m and the elastic foundation coefficient of the backfill body in the gob is 80 MN/m3.In such condition,the roof subsidence could be controlled effectively.In the meantime,combined with the monitoring results of convergence between roof and floor in No.9301 roadway of Tangkou Coal Mine,the filed measurement showed that the maximum convergence of roof and floor was 213 mm，the surrounding rock control in the gob side entry was effective.
Abstract：
According to the problem of surrounding rock supporting and stability of equipment remove gateway in ultra-thick seam fully-mechanized caving faces in Suancigou Mine, the deformation and failure characteristics of the surrounding rock of equipment remove gateway are analyzed by field measurements and numerical simulation, the combined supporting technology of cable anchor in equipment remove gateway is put forward. The result shows that when the distance is 30 m between working face and equipment remove gateway, plastic collapse of surrounding rock begins to increase, when the distance is 10 m between working face and equipment remove gateway, plastic collapse of surrounding rock is severe, after working face is connected with equipment remove gateway, the depth of plastic zone of roof reaches 7 m, roof near the coal wall is deeper, the depth of plastic zone of coal pillar is 3.5 m. According to the deformation and failure characteristics of surrounding rock of equipment removal channel, adhering to the principle of controlling "roof and pillar ", the combined supporting technology of cable anchor is used. This technology has been successfully applied in No.6up-109 equipment remove gateway, the equipment has been successfully withdrawn.
According to the problem of surrounding rock supporting and stability of equipment remove gateway in ultra-thick seam fully-mechanized caving faces in Suancigou Mine, the deformation and failure characteristics of the surrounding rock of equipment remove gateway are analyzed by field measurements and numerical simulation, the combined supporting technology of cable anchor in equipment remove gateway is put forward. The result shows that when the distance is 30 m between working face and equipment remove gateway, plastic collapse of surrounding rock begins to increase, when the distance is 10 m between working face and equipment remove gateway, plastic collapse of surrounding rock is severe, after working face is connected with equipment remove gateway, the depth of plastic zone of roof reaches 7 m, roof near the coal wall is deeper, the depth of plastic zone of coal pillar is 3.5 m. According to the deformation and failure characteristics of surrounding rock of equipment removal channel, adhering to the principle of controlling "roof and pillar ", the combined supporting technology of cable anchor is used. This technology has been successfully applied in No.6up-109 equipment remove gateway, the equipment has been successfully withdrawn.
Abstract：
According to the fact that the roof of large span roadway in thick coal was soft and broken and the separation of expansion was easily happened in this roof.These features can easily led to the broken of anchor ropes and the destruction of support structure,and caused the roof fall accident.The large area roof fall of No.20322 haulageway during roadway excavation was chosen as the research background.By the theory analysis and numerical modelling,the paper analysised the pressure phenomenon before the roadway roof-fall accident.The results indicated that the main reasons for the instability of the roof structure were the fractured surrounding rock and the unreasonable parameters of anchor cables.The supporting idea of enhance the integrity and strength of the roof support structure through the adjustment of the anchor cable supporting parameters to control the soft thick coal roof was proposed and good results have been achieved in the practice of the industry.
According to the fact that the roof of large span roadway in thick coal was soft and broken and the separation of expansion was easily happened in this roof.These features can easily led to the broken of anchor ropes and the destruction of support structure,and caused the roof fall accident.The large area roof fall of No.20322 haulageway during roadway excavation was chosen as the research background.By the theory analysis and numerical modelling,the paper analysised the pressure phenomenon before the roadway roof-fall accident.The results indicated that the main reasons for the instability of the roof structure were the fractured surrounding rock and the unreasonable parameters of anchor cables.The supporting idea of enhance the integrity and strength of the roof support structure through the adjustment of the anchor cable supporting parameters to control the soft thick coal roof was proposed and good results have been achieved in the practice of the industry.
Abstract：
In order to ensure safety during driving in gob and stability of surrounding rock in service period, taking equipment roadway of No.1 middle yard as research object, this article studied the adaptability of pipe-shed and capsular bag grouting support technique for gob roadway support by the methods of theoretical analysis, field test and field monitoring, and using the method of cross distribution point continuouslly observed roadway surface displacement for two months, the study results showed that the pipe-shed and capsular bay grouting as advance supporting and the fiexible supports+backfill grouting as permanent support had the advantages of rapid driving speed and support stability, and monitoring results of roadway surface displacement showed that surrounding rock deformation was effectively controlled, the maximum roof convergence was 60 mm, the maximum displacement of side-to-side was 130 mm, the maximum floor heave was 80 mm.
In order to ensure safety during driving in gob and stability of surrounding rock in service period, taking equipment roadway of No.1 middle yard as research object, this article studied the adaptability of pipe-shed and capsular bag grouting support technique for gob roadway support by the methods of theoretical analysis, field test and field monitoring, and using the method of cross distribution point continuouslly observed roadway surface displacement for two months, the study results showed that the pipe-shed and capsular bay grouting as advance supporting and the fiexible supports+backfill grouting as permanent support had the advantages of rapid driving speed and support stability, and monitoring results of roadway surface displacement showed that surrounding rock deformation was effectively controlled, the maximum roof convergence was 60 mm, the maximum displacement of side-to-side was 130 mm, the maximum floor heave was 80 mm.
Abstract：
According to severe strata behaviors occur frequently during the primary mining of the panels under contiguous goaf,In Shendong mining area and it is urgent to know about its reasons.the strata behavior characteristics and its mechanism in different regions during the primary mining are analyzed based on field test and relevent theories.The results show that compared with conventional panels in the upper coal seam,strata behavior of the lower coal seam has obvious aperiodicity and zoning characteristics.Moreover,the weighting positions during the primary of the panel in close-distance goaf coincide with the top coal pillar and the first fracture position of the overlying key strata,and then based on that,the strata behaviors during primary mining are zoning.Strata movement structure and mechanical models in different strata behavior regions during the primary mining are established and the mechanisms of those regions are analyzed.For the region passing the overlying one-side mining pillar,the strata behavior is under the coupling effect of the breaking of key strata and the distance between coal seams,and it is the distance that leads to the eccentric strata behaviors along the panel.For the rest regions under the overlying goaf,the broken coal and rock mass has little influence on the strata behaviors during the weighting ,but has a great influence on that of non weighting period.Some effective control measures are given finally.choosing the open-off cut position and increasing the advancing speed reasonably.
According to severe strata behaviors occur frequently during the primary mining of the panels under contiguous goaf,In Shendong mining area and it is urgent to know about its reasons.the strata behavior characteristics and its mechanism in different regions during the primary mining are analyzed based on field test and relevent theories.The results show that compared with conventional panels in the upper coal seam,strata behavior of the lower coal seam has obvious aperiodicity and zoning characteristics.Moreover,the weighting positions during the primary of the panel in close-distance goaf coincide with the top coal pillar and the first fracture position of the overlying key strata,and then based on that,the strata behaviors during primary mining are zoning.Strata movement structure and mechanical models in different strata behavior regions during the primary mining are established and the mechanisms of those regions are analyzed.For the region passing the overlying one-side mining pillar,the strata behavior is under the coupling effect of the breaking of key strata and the distance between coal seams,and it is the distance that leads to the eccentric strata behaviors along the panel.For the rest regions under the overlying goaf,the broken coal and rock mass has little influence on the strata behaviors during the weighting ,but has a great influence on that of non weighting period.Some effective control measures are given finally.choosing the open-off cut position and increasing the advancing speed reasonably.
Abstract：
According to the limitation of the available expansion constitutive model, based on the humidity field theory and expansion test, the expansion rates of the free expansion and loaded expansion under the lateral restraint were analyzed and the derived constitutive model would have the theoretical base. Among them, the parameter variation would have the physical significance. The study result showed that in the expansion constitutive model, the strain and stress logarithms and the stress linear combination would be in negative correlation function relationship. When an axial stress was small, a logarithmic function fitting could be applied approximately. When an axial stress was high, a linear function fitting could be applied approximately. A water absorption rate of the expansive rock and the axial stress would be in a negative logarithmic function relation.In the fitted constitutive model, the related coefficient would be over 0.97 and could say that the constitutive model could have a good consistency to the related data fitting. The study results could provide the guidance to the 3D expansive theory.
According to the limitation of the available expansion constitutive model, based on the humidity field theory and expansion test, the expansion rates of the free expansion and loaded expansion under the lateral restraint were analyzed and the derived constitutive model would have the theoretical base. Among them, the parameter variation would have the physical significance. The study result showed that in the expansion constitutive model, the strain and stress logarithms and the stress linear combination would be in negative correlation function relationship. When an axial stress was small, a logarithmic function fitting could be applied approximately. When an axial stress was high, a linear function fitting could be applied approximately. A water absorption rate of the expansive rock and the axial stress would be in a negative logarithmic function relation.In the fitted constitutive model, the related coefficient would be over 0.97 and could say that the constitutive model could have a good consistency to the related data fitting. The study results could provide the guidance to the 3D expansive theory.
Abstract：
Based on the experimental analysis of the uniaxial compression process of raw coal samples, the change of transient charge on sample surface is studied and the relationship betweene transient charge and loading stress is discussed.The result show that during the main rupture stage of coal samples,the maximum of the transient charge signals appears before the stress peak,and changes suddenly with the abrupt drop of the stress.At the early stage of destruction,the internal friction is the main reason for the charge generation and accumulation.While at the middle and late stages of destruction,a large number of cracks are formed and propagated,which cause the change of charge signals.According to the variation law of the transient charge on the surface of the coal body,it can reflect the damage of the coal body,and the monitoring of the surface charge can provide an important reference for the prediction of coal and rock dynamic disasters.
Based on the experimental analysis of the uniaxial compression process of raw coal samples, the change of transient charge on sample surface is studied and the relationship betweene transient charge and loading stress is discussed.The result show that during the main rupture stage of coal samples,the maximum of the transient charge signals appears before the stress peak,and changes suddenly with the abrupt drop of the stress.At the early stage of destruction,the internal friction is the main reason for the charge generation and accumulation.While at the middle and late stages of destruction,a large number of cracks are formed and propagated,which cause the change of charge signals.According to the variation law of the transient charge on the surface of the coal body,it can reflect the damage of the coal body,and the monitoring of the surface charge can provide an important reference for the prediction of coal and rock dynamic disasters.
Abstract：
In order to study the cracking network structure and the surface cracking evolution development process of the coal and rock mass,a triaxial loading test was conducted based on the mining stress path of the coal and rock mass.A loading operation was stopped when the stress was just over the peak stress and the pre-fractured coal and rock mass under the mining stress role were obtained.Then the DIC technology was introduced,an uniaxial loading was continued and the cracking evolution development process was observed and recorded.In combination with the fractal geometry,a fractal dimension of the surface cracking on the coal and rock in different loading stage was calculated.The study result showed that under the real mining stress path,with the influence of the surrounding pressure released,the loading capacity of the coal and rock was reduced over 40%.Due to the different roughness of the cracking surface and the heterogeneity and insitu defects,except for the continuous deformation and failure along the pre-fractured cracking surface,the pre-fractured coal and rock mass would occur new secondary cracking.Under the condition of the uniaxial compression,the fractal dimension of the cracking on the surface of the coal and rock mass would be increased from 1.12 to 1.60,and the completed tendency of the cracking evolution would be slow to rapid developed to steady stable.
In order to study the cracking network structure and the surface cracking evolution development process of the coal and rock mass,a triaxial loading test was conducted based on the mining stress path of the coal and rock mass.A loading operation was stopped when the stress was just over the peak stress and the pre-fractured coal and rock mass under the mining stress role were obtained.Then the DIC technology was introduced,an uniaxial loading was continued and the cracking evolution development process was observed and recorded.In combination with the fractal geometry,a fractal dimension of the surface cracking on the coal and rock in different loading stage was calculated.The study result showed that under the real mining stress path,with the influence of the surrounding pressure released,the loading capacity of the coal and rock was reduced over 40%.Due to the different roughness of the cracking surface and the heterogeneity and insitu defects,except for the continuous deformation and failure along the pre-fractured cracking surface,the pre-fractured coal and rock mass would occur new secondary cracking.Under the condition of the uniaxial compression,the fractal dimension of the cracking on the surface of the coal and rock mass would be increased from 1.12 to 1.60,and the completed tendency of the cracking evolution would be slow to rapid developed to steady stable.
Abstract：
In order to compare with the theoretical predicted results and the experiment results between the conventional max circumferential stress criterion and the corrected max circumferential stress criterion with the consideration of the T stress, the accuracy of the corrected max circumferential stress crack extension criterion established was verified. The T stress affected to the fracture toughness and the crack extension law was obtained. The three point bending half disc specimen was applied to study on the Type Ⅰ-Ⅱ complex fracture toughness and the crack initial extension angle with the change of the pre-cracking orientation. The study results showed that when the T stress was considered, the pure I type cracking extension angle would not be kept as 0 and the cracking extension orientation would be deflection. As for the Type Ⅰ-Ⅱ complex fracture, when the T stress was positive, the anti-cracking continuous extension capacity of the material would be enhanced and the fracture strength would be increased. When the T stress was negative, the anti cracking continuous extension capacity of the material would be weakened and the fracture toughness would be reduced. The T stress affected to the crack fracturing angle and the critical stress strength factor could not be ignored and especially would have obvious influence to the Type Ⅱ fracture. The GMTS criterion could be better to predict the compound crack initial extension angle and the fracture toughness of the rock.
In order to compare with the theoretical predicted results and the experiment results between the conventional max circumferential stress criterion and the corrected max circumferential stress criterion with the consideration of the T stress, the accuracy of the corrected max circumferential stress crack extension criterion established was verified. The T stress affected to the fracture toughness and the crack extension law was obtained. The three point bending half disc specimen was applied to study on the Type Ⅰ-Ⅱ complex fracture toughness and the crack initial extension angle with the change of the pre-cracking orientation. The study results showed that when the T stress was considered, the pure I type cracking extension angle would not be kept as 0 and the cracking extension orientation would be deflection. As for the Type Ⅰ-Ⅱ complex fracture, when the T stress was positive, the anti-cracking continuous extension capacity of the material would be enhanced and the fracture strength would be increased. When the T stress was negative, the anti cracking continuous extension capacity of the material would be weakened and the fracture toughness would be reduced. The T stress affected to the crack fracturing angle and the critical stress strength factor could not be ignored and especially would have obvious influence to the Type Ⅱ fracture. The GMTS criterion could be better to predict the compound crack initial extension angle and the fracture toughness of the rock.
Abstract：
In order to study the deformation features of the in-pit dumping site of Yuanbaoshan Surface Mine,based on the control and calculation on the deformation of the bulky soil as the main object,a rheological test was applied to determine the numerical calculation parameters and the Burgers creep model was applied to the analysis on a settlement law of the dumping site in the backfill process and after the backfill completed.And in the vertical direction,a slicing treatment was conducted on the in-pit dumping site.With the dumping height increased,under the dynamic load role of the top overburden,each slicing all would have settlements occurred.With the establishment of the Burgers creep model suitable to the in-pit dumping site,the settlement,displacement and late settlement law in the filling process were analyzed.The calculation results showed that in the rolling area,a max late settlement was 30.7 cm and the horizontal displacement was 27.3 cm.At the year end of 2020,a river channel would be constructed and would meet the deformation requirement of the river.At the non rolling area,the max late settlement was 2.74 m and the horizontal displacement was 2.12 m.The dumping operation of the in-pit dumping site would be completed after 2.5 years and the soil deformation and settlement would be basically completed.
In order to study the deformation features of the in-pit dumping site of Yuanbaoshan Surface Mine,based on the control and calculation on the deformation of the bulky soil as the main object,a rheological test was applied to determine the numerical calculation parameters and the Burgers creep model was applied to the analysis on a settlement law of the dumping site in the backfill process and after the backfill completed.And in the vertical direction,a slicing treatment was conducted on the in-pit dumping site.With the dumping height increased,under the dynamic load role of the top overburden,each slicing all would have settlements occurred.With the establishment of the Burgers creep model suitable to the in-pit dumping site,the settlement,displacement and late settlement law in the filling process were analyzed.The calculation results showed that in the rolling area,a max late settlement was 30.7 cm and the horizontal displacement was 27.3 cm.At the year end of 2020,a river channel would be constructed and would meet the deformation requirement of the river.At the non rolling area,the max late settlement was 2.74 m and the horizontal displacement was 2.12 m.The dumping operation of the in-pit dumping site would be completed after 2.5 years and the soil deformation and settlement would be basically completed.
Abstract：
In order to solve a hard artificial establishment problem of the topological relationship in the mine ventilation system,establishment of ventilation system storage structure and automatic numbering realization of mode was studied,a programming technology was applied to realize the automatic establishment on the topological relationship of the main ventilation system.The results showed that the storage ventilation network of the data structure in the sequence list applied could speed up the data reading speed and meanwhile could reduce the requirements of the storage space.The establishment on the storage structure of the ventilation power could avoid a “false convergence” condition occurred and could optimize the characteristic curve of the ventilator.The storage structure of the ventilation facility established could optimize the treatment mode of the ventilation facility in the network resolution.In a large extent,the path search and the network resolution complicated could be reduced and thus the calculation speed and efficiency would be improved.The automatic numbering of the node could improve the efficiency and accuracy of the topological relationship established in the ventilation system and could provide a convenient and fast to the daily management and maintenance work of the ventilation system.The study applied to verify a ventilation system in a large mine could reduce 34.2% of the convergence time of the network resolution.
In order to solve a hard artificial establishment problem of the topological relationship in the mine ventilation system,establishment of ventilation system storage structure and automatic numbering realization of mode was studied,a programming technology was applied to realize the automatic establishment on the topological relationship of the main ventilation system.The results showed that the storage ventilation network of the data structure in the sequence list applied could speed up the data reading speed and meanwhile could reduce the requirements of the storage space.The establishment on the storage structure of the ventilation power could avoid a “false convergence” condition occurred and could optimize the characteristic curve of the ventilator.The storage structure of the ventilation facility established could optimize the treatment mode of the ventilation facility in the network resolution.In a large extent,the path search and the network resolution complicated could be reduced and thus the calculation speed and efficiency would be improved.The automatic numbering of the node could improve the efficiency and accuracy of the topological relationship established in the ventilation system and could provide a convenient and fast to the daily management and maintenance work of the ventilation system.The study applied to verify a ventilation system in a large mine could reduce 34.2% of the convergence time of the network resolution.
Abstract：
In order to have an optimal layout location to measure an average air velocity in a mine roadway with the wind air velocity sensor in the wind measuring station of an underground mine, based on the wind measuring station in a -175 m level and an air income crosscut of Baiping Underground Mine, Zhengzhou Coal Group as the study object, according to the measured ventilation parameters of the wind measuring station in the mine roadway, a CFD calculation model of the mine roadway air velocity field was established in the wind measuring station. In comparison with the site measured results and the simulation results, the reliability of the simulation calculation by the CFD model of the mine roadway air velocity field in the wind measuring station was verified. The CFD model of the mine roadway air velocity field in the wind measuring station was applied to the quantitative simulation analysis on the mine roadway wind measuring station with the personnel of the station under the condition of the extreme location. The study results showed that the optimum layout area of the air velocity sensor would be a zone distance of 3.63 m, 3.64 m from the mine roadway floor distance to the central vertical line of the mine roadway in the wind measuring station. The air velocity sensor set up within the area could ensure the personnel in the area near the wind measuring station have the wind measuring accuracy of the air velocity sensor in the wind measuring station and they would provide the science guidance and proposals on the accurate wind measuring work in the mine roadway.
In order to have an optimal layout location to measure an average air velocity in a mine roadway with the wind air velocity sensor in the wind measuring station of an underground mine, based on the wind measuring station in a -175 m level and an air income crosscut of Baiping Underground Mine, Zhengzhou Coal Group as the study object, according to the measured ventilation parameters of the wind measuring station in the mine roadway, a CFD calculation model of the mine roadway air velocity field was established in the wind measuring station. In comparison with the site measured results and the simulation results, the reliability of the simulation calculation by the CFD model of the mine roadway air velocity field in the wind measuring station was verified. The CFD model of the mine roadway air velocity field in the wind measuring station was applied to the quantitative simulation analysis on the mine roadway wind measuring station with the personnel of the station under the condition of the extreme location. The study results showed that the optimum layout area of the air velocity sensor would be a zone distance of 3.63 m, 3.64 m from the mine roadway floor distance to the central vertical line of the mine roadway in the wind measuring station. The air velocity sensor set up within the area could ensure the personnel in the area near the wind measuring station have the wind measuring accuracy of the air velocity sensor in the wind measuring station and they would provide the science guidance and proposals on the accurate wind measuring work in the mine roadway.
Abstract：
In order to study the porous structure and the gas diffusion characteristics of the primary structure coal and the tectonic coal, a mercury intrusion, cryogenic liquid nitrogen, carbon dioxide adsorption and pressure stabilized adsorption experiment were applied to the experiment study on the experimental coal samples. The paper had an analysis on the porous structure characteristics of the primary structure coal and the tectonic coal and as well as the time effect of the adsorbed gas under the partical condition. A relationship between the pore complicated degree and the gas migration fast and slow speed in the coal partical of the primary structure coal and tectonic coal was obtained. The study showed that in Qinan Mine and Daning Mine, the micropore length of the primary structure coal was 8.087×1010 m/g and 1.202×1011 m/g individually and the micropore length of the tectonic coal was 6.932×1010 m/g and 1.090×1011 m/g individually. Under the certain condition of the experiment coal samples, the adsorption of the primary structure coal to reach a balanced state would have a required time far longer than the tectonic coal. In the first three minutes, the average adsorption rate of the tectonic coal would be 3.3 and 3.8 times higher than the primary structure coal individually. In the coal samples, the smaller the micropore length, the shorter diffusion path of the gas in the coal would be, the shorter time required of the migration would be and the higher gas adsorption volume in the initial period would be.
In order to study the porous structure and the gas diffusion characteristics of the primary structure coal and the tectonic coal, a mercury intrusion, cryogenic liquid nitrogen, carbon dioxide adsorption and pressure stabilized adsorption experiment were applied to the experiment study on the experimental coal samples. The paper had an analysis on the porous structure characteristics of the primary structure coal and the tectonic coal and as well as the time effect of the adsorbed gas under the partical condition. A relationship between the pore complicated degree and the gas migration fast and slow speed in the coal partical of the primary structure coal and tectonic coal was obtained. The study showed that in Qinan Mine and Daning Mine, the micropore length of the primary structure coal was 8.087×1010 m/g and 1.202×1011 m/g individually and the micropore length of the tectonic coal was 6.932×1010 m/g and 1.090×1011 m/g individually. Under the certain condition of the experiment coal samples, the adsorption of the primary structure coal to reach a balanced state would have a required time far longer than the tectonic coal. In the first three minutes, the average adsorption rate of the tectonic coal would be 3.3 and 3.8 times higher than the primary structure coal individually. In the coal samples, the smaller the micropore length, the shorter diffusion path of the gas in the coal would be, the shorter time required of the migration would be and the higher gas adsorption volume in the initial period would be.
Abstract：
In order to discover the organic solvent effect in the new organic fracturing fluid to the high rank coal, different organic solvents were applied to the solvent extraction of the high rank coal from Changzhi, Shanxi. With the measured results of the contact angel and cryogenic nitrogen adsorption experiment, an analysis was conducted on the surface and porosity difference variation and causes of the high rank coal under the different solvent reconstruction. The study result showed that after the effect of the organic solvent, the coal-water contract angle would be obviously increased, the surface tension would remarkably decreased and the above showed that after the treatment, the hydrophobicity of the coal samples was enhanced. After the treatment of the different solvent, the BET specific surface area and the BJH specific pore volume of the coal samples would be increased in different degree. Among them, after the reconstruction with the acetone, the coal sample volume was increased in largest. The organic solvent would have the pore enlarged effect of the coal sample and the pore enlarged effect of the micro pore would be obvious. By a comparison, after the carbon disulfide, acetone and peracetic acid treated, the open pore and large pore content of the coal sample would be obviously increased and connection of the pores would be obviously improved. The tetrahydrofuran, triethylamine and ethanol solvents would have weaker improvement to the coal sample pores.
In order to discover the organic solvent effect in the new organic fracturing fluid to the high rank coal, different organic solvents were applied to the solvent extraction of the high rank coal from Changzhi, Shanxi. With the measured results of the contact angel and cryogenic nitrogen adsorption experiment, an analysis was conducted on the surface and porosity difference variation and causes of the high rank coal under the different solvent reconstruction. The study result showed that after the effect of the organic solvent, the coal-water contract angle would be obviously increased, the surface tension would remarkably decreased and the above showed that after the treatment, the hydrophobicity of the coal samples was enhanced. After the treatment of the different solvent, the BET specific surface area and the BJH specific pore volume of the coal samples would be increased in different degree. Among them, after the reconstruction with the acetone, the coal sample volume was increased in largest. The organic solvent would have the pore enlarged effect of the coal sample and the pore enlarged effect of the micro pore would be obvious. By a comparison, after the carbon disulfide, acetone and peracetic acid treated, the open pore and large pore content of the coal sample would be obviously increased and connection of the pores would be obviously improved. The tetrahydrofuran, triethylamine and ethanol solvents would have weaker improvement to the coal sample pores.
Abstract：
Based on the efficiency of the mathematical model verified with the experiment and the heat absorption from the mine ventilation air oxidized bed, a numerical study method was applied to study the heat absorption space features(honeycomb ceramic filling rate and honeycomb ceramic hole opening rate) of the mine ventilation air methane oxidized bed affected to the heat absorption. The calculation results showed that when the honeycomb ceramic filling rate of the heat absorption space increased, on one hand, the bed physical velocity of the oxidized bed would be increased, the gas flow rate around the external wall of the heat exchanger would be increased and the convection heat transfer of the heat exchanger would be enhanced. On the other hand, the gas flow of the heat exchanger directly to the convection heat exchanger was reduced, the heat absorption of the heat exchanger was weakened, the honeycomb ceramic filling rate of the heat absorption space would increase the contradiction dual characters of the heat absorption, which would make the heat absorption rate of the heat exchanger firstly increased and then decreased. When the filling rate was 0.49, there would be the maximum existed in the heat absorption rate of the internal heat exchanger within the oxidized bed. The hole opening rate of the filling honeycomb ceramics in the heat absorption space reduced would cause a mismatch of the resistance between the heat exchanger area and the honeycomb ceramic filling area within the heat absorption space, the gas would be priority to select the area of the heat exchanger with a small resistance and would enhance the heat absorption of the heat exchanger. But the resistance difference of the heat exchanger too high would affect the distribution uniformity of the downstream bed gas in the heat absorption are and the hole opening rate of the filling honeycomb ceramic in the heat absorption space would be 0.64 as selected.
Based on the efficiency of the mathematical model verified with the experiment and the heat absorption from the mine ventilation air oxidized bed, a numerical study method was applied to study the heat absorption space features(honeycomb ceramic filling rate and honeycomb ceramic hole opening rate) of the mine ventilation air methane oxidized bed affected to the heat absorption. The calculation results showed that when the honeycomb ceramic filling rate of the heat absorption space increased, on one hand, the bed physical velocity of the oxidized bed would be increased, the gas flow rate around the external wall of the heat exchanger would be increased and the convection heat transfer of the heat exchanger would be enhanced. On the other hand, the gas flow of the heat exchanger directly to the convection heat exchanger was reduced, the heat absorption of the heat exchanger was weakened, the honeycomb ceramic filling rate of the heat absorption space would increase the contradiction dual characters of the heat absorption, which would make the heat absorption rate of the heat exchanger firstly increased and then decreased. When the filling rate was 0.49, there would be the maximum existed in the heat absorption rate of the internal heat exchanger within the oxidized bed. The hole opening rate of the filling honeycomb ceramics in the heat absorption space reduced would cause a mismatch of the resistance between the heat exchanger area and the honeycomb ceramic filling area within the heat absorption space, the gas would be priority to select the area of the heat exchanger with a small resistance and would enhance the heat absorption of the heat exchanger. But the resistance difference of the heat exchanger too high would affect the distribution uniformity of the downstream bed gas in the heat absorption are and the hole opening rate of the filling honeycomb ceramic in the heat absorption space would be 0.64 as selected.
Abstract：
In order to study on monitor parameters and correlation of acoustic emission intensity-electromagnetic radiation intensity-gas concentration and K1, based on the damage mechanics of the continuous medium, the paper analyzed the principles of the acoustic emission and the electromagnetic radiation technology applied to monitor the coal and gas outburst. A KJ838 sound-electricity-gas system was applied to the tracking monitoring of No.11224 transportation and heading roadway in Jinjia Mine. The results showed that the KJ838 sound-electricity-gas system could timely respond the environment variation in the mine roadway, including the acoustic emission, electromagnetic radiation, gas density characteristics variation occurred during the blasting period. Meanwhile,there was a good correlation between the conventional predicted index K1 values. The analysis results could provide the references to the late determination on the real time multi parameters monitoring and early warning model of the coal and gas outburst and the establishment of the early warning platform.
In order to study on monitor parameters and correlation of acoustic emission intensity-electromagnetic radiation intensity-gas concentration and K1, based on the damage mechanics of the continuous medium, the paper analyzed the principles of the acoustic emission and the electromagnetic radiation technology applied to monitor the coal and gas outburst. A KJ838 sound-electricity-gas system was applied to the tracking monitoring of No.11224 transportation and heading roadway in Jinjia Mine. The results showed that the KJ838 sound-electricity-gas system could timely respond the environment variation in the mine roadway, including the acoustic emission, electromagnetic radiation, gas density characteristics variation occurred during the blasting period. Meanwhile,there was a good correlation between the conventional predicted index K1 values. The analysis results could provide the references to the late determination on the real time multi parameters monitoring and early warning model of the coal and gas outburst and the establishment of the early warning platform.
Abstract：
In order to solve a low intelligent degree, poor accuracy and other problems of the available mine height measuring plan for the hydraulic powered support, a height measuring plan of the hydraulic powered support under different attitude was studied, a design method of height measuring system based on inclination sensor was provided for the mine hydraulic powered support and the height measuring system of the mine hydraulic powered support was established based on the inclined sensor. And according to the strong electromagnetic and vibration interference caused the signal degradation problem in the underground mine, the wavelet decomposition and reconstruction were conducted on the collected data and the accuracy of the height measuring system was improved under the harsh environment. Meanwhile,from the aspects to improve the anti-interference capability of the communication, to increase the transmission distance and others, the further study orientation was provided. The height measuring system of the mine hydraulic powered support was tested in the lab and the underground mine. The results showed that under the harsh environment, the error of the height measuring system was within 10 cm and could meet the actual requirements of the coal mining face.
In order to solve a low intelligent degree, poor accuracy and other problems of the available mine height measuring plan for the hydraulic powered support, a height measuring plan of the hydraulic powered support under different attitude was studied, a design method of height measuring system based on inclination sensor was provided for the mine hydraulic powered support and the height measuring system of the mine hydraulic powered support was established based on the inclined sensor. And according to the strong electromagnetic and vibration interference caused the signal degradation problem in the underground mine, the wavelet decomposition and reconstruction were conducted on the collected data and the accuracy of the height measuring system was improved under the harsh environment. Meanwhile,from the aspects to improve the anti-interference capability of the communication, to increase the transmission distance and others, the further study orientation was provided. The height measuring system of the mine hydraulic powered support was tested in the lab and the underground mine. The results showed that under the harsh environment, the error of the height measuring system was within 10 cm and could meet the actual requirements of the coal mining face.
Abstract：
The characteristics of the underground coal mine personnel positioning are analyzed and summarized: the coverage is much larger than the indoor environment; the transmission of the positioning signal should be not line of sight; the attenuation of electromagnetic wave is serious; the attenuation of wireless transmission is affected by the gallery branching, bending, inclination, the area and shape of cross-sectional, the medium of surrounding rock, the roughness of gallery surface, support, longitudinal conductors, transverse conductors, equipment and etc; theelectrical equipment must be explosion-proof; the underground coal mine environment is harsh because of dust, moisture, water and etc.It is proposed that the radio transmission is suitable for the underground coal mine personnel positioning; while ultrasonic, laser, and infrared transmissions are not suitable for underground coal mine personnel positioning.And, it is proposed that the positioning method based on received signal strength indication(RSSI) is not suitable for underground coal mine accurate personnel positioning; the positioning method based on angle of arrival(AOA) measurement is not suitable for underground coal mine accurate personnel positioning; the positioning method based on time of arrival(TOA) and the positioning method based on time difference of arrival(TDOA) within similar signal source are suitable for underground coal mine accurate personnel positioning, and the positioning system based on time difference of arrival(TDOA) within similar signal source costs less than the positioning method based on time of arrival(TOA); the positioning method based on time difference of arrival(TDOA) within different types of signal source is not suitable for underground coal mine accurate personnel positioning.
The characteristics of the underground coal mine personnel positioning are analyzed and summarized: the coverage is much larger than the indoor environment; the transmission of the positioning signal should be not line of sight; the attenuation of electromagnetic wave is serious; the attenuation of wireless transmission is affected by the gallery branching, bending, inclination, the area and shape of cross-sectional, the medium of surrounding rock, the roughness of gallery surface, support, longitudinal conductors, transverse conductors, equipment and etc; theelectrical equipment must be explosion-proof; the underground coal mine environment is harsh because of dust, moisture, water and etc.It is proposed that the radio transmission is suitable for the underground coal mine personnel positioning; while ultrasonic, laser, and infrared transmissions are not suitable for underground coal mine personnel positioning.And, it is proposed that the positioning method based on received signal strength indication(RSSI) is not suitable for underground coal mine accurate personnel positioning; the positioning method based on angle of arrival(AOA) measurement is not suitable for underground coal mine accurate personnel positioning; the positioning method based on time of arrival(TOA) and the positioning method based on time difference of arrival(TDOA) within similar signal source are suitable for underground coal mine accurate personnel positioning, and the positioning system based on time difference of arrival(TDOA) within similar signal source costs less than the positioning method based on time of arrival(TOA); the positioning method based on time difference of arrival(TDOA) within different types of signal source is not suitable for underground coal mine accurate personnel positioning.
Abstract：
In order to predict a fatigue failure time of the flat ring applied to the chains of the scraper conveyor,based on the test load data,a prediction of the service life was conducted. Based on a ø38 mm×137 mm C grade type chain ring as the study object,a tensile strain test device was applied to the online monitoring and measuring of the chain tensile to the scraper conveyor. The flat ring strain loading data of the conveyor chains with 10 working periods were obtained. In combination with the tension numerical calibration,rain flow method,Goodman model and other means,a data processing,analysis and average stress correction were conducted on these data obtained. The yield limit of the chain ring material was applied to estimate the fatigue characteristic curve of the chain ring. The study results showed that the shaft shoulder point of the chain flat ring applied to the scraper conveyor would be the weak point of the strength,a stress concentration phenomenon would be easily occurred and the max stress value would be 719.5 MPa. The analysis on the fatigue life of the flat ring showed that the average service life of the chain flat ring applied to the scraper conveyor would be 42 050 circulations and the gearing between the sprocket and the chain link would be 84 100 times. The conclusion could have important reference significances to the structure design and optimization of the scraper chain link as well as the time references to the maintenances and replacement.
In order to predict a fatigue failure time of the flat ring applied to the chains of the scraper conveyor,based on the test load data,a prediction of the service life was conducted. Based on a ø38 mm×137 mm C grade type chain ring as the study object,a tensile strain test device was applied to the online monitoring and measuring of the chain tensile to the scraper conveyor. The flat ring strain loading data of the conveyor chains with 10 working periods were obtained. In combination with the tension numerical calibration,rain flow method,Goodman model and other means,a data processing,analysis and average stress correction were conducted on these data obtained. The yield limit of the chain ring material was applied to estimate the fatigue characteristic curve of the chain ring. The study results showed that the shaft shoulder point of the chain flat ring applied to the scraper conveyor would be the weak point of the strength,a stress concentration phenomenon would be easily occurred and the max stress value would be 719.5 MPa. The analysis on the fatigue life of the flat ring showed that the average service life of the chain flat ring applied to the scraper conveyor would be 42 050 circulations and the gearing between the sprocket and the chain link would be 84 100 times. The conclusion could have important reference significances to the structure design and optimization of the scraper chain link as well as the time references to the maintenances and replacement.
Abstract：
In order to have the mechanical-hydraulic coupling rigidity characteristics of the hydraulic powered support,an analysis was firstly conducted on the structure dynamics of the hydraulic powered support and the Jacobian matrix to represent a mapping relationship of the driving system between the input rigidity and output rigidity was obtained.Thus the relationship between the mechanical-hydraulic coupling rigidity and the hydraulic parameters of the hydraulic cylinder,the powered support structure type parameter sand attitude parameters of the hydraulic powered support were provided.With the different location point on the canopy selected,the variable parameter calculation was conducted on the horizontal,vertical and rotary directional rigidities of the powered support with the variation law of each parameter.The result showed that the vertical rigidity of the powered support was determined by the leg rigidity mainly and the rotary rigidity of the powered support was depended on the rigidity and the action location of the balance hydraulic cylinder.Relative to the attitude parameters of the powered support,the hydraulic parameters of the hydraulic cylinder and the structure type parameters of the powered support has a high influences to the rigidity of the powered support.Those results could provide the basis to the modeling on single element stability evaluation of the hydraulic powered support and could improve the stress state of the hydraulic powered support applied in the coal mining face.
In order to have the mechanical-hydraulic coupling rigidity characteristics of the hydraulic powered support,an analysis was firstly conducted on the structure dynamics of the hydraulic powered support and the Jacobian matrix to represent a mapping relationship of the driving system between the input rigidity and output rigidity was obtained.Thus the relationship between the mechanical-hydraulic coupling rigidity and the hydraulic parameters of the hydraulic cylinder,the powered support structure type parameter sand attitude parameters of the hydraulic powered support were provided.With the different location point on the canopy selected,the variable parameter calculation was conducted on the horizontal,vertical and rotary directional rigidities of the powered support with the variation law of each parameter.The result showed that the vertical rigidity of the powered support was determined by the leg rigidity mainly and the rotary rigidity of the powered support was depended on the rigidity and the action location of the balance hydraulic cylinder.Relative to the attitude parameters of the powered support,the hydraulic parameters of the hydraulic cylinder and the structure type parameters of the powered support has a high influences to the rigidity of the powered support.Those results could provide the basis to the modeling on single element stability evaluation of the hydraulic powered support and could improve the stress state of the hydraulic powered support applied in the coal mining face.
Abstract：
In order to solve a cumbersome of the available screening equipment and a not suitable fine coal sample preparation problem of the coal samples, a repeated applied inclined screen for a small rotary vibration screen was provided. Based on a multimer kinematics theory, a virtual prototype technology was applied to simulate the kinematic characteristics of the materials on the screen. With the comparison on the kinematic track, speed and angular speed curve of the material under the revolution of five set electric motors, the best motor revolution of the material kinematic characteristics and the interval between the motor speeds in the late test were obtained. A screening efficiency test was conducted at the interval of the manufactured test equipment and the verification was conducted on the simulation results. The result showed that when the material kinematic characteristics were in optimum, a max interval of the motor speed obtained from the simulation was 600 ～ 1 200 r/min. After the test conducted at the interval, the screening effect obtained within a motor speed ranging from 960 ～ 1 020 r/min was best and the simulation results could tally with the test results. The study could provide a new method to design the screen equipment and could provide an important basis to the late study.
In order to solve a cumbersome of the available screening equipment and a not suitable fine coal sample preparation problem of the coal samples, a repeated applied inclined screen for a small rotary vibration screen was provided. Based on a multimer kinematics theory, a virtual prototype technology was applied to simulate the kinematic characteristics of the materials on the screen. With the comparison on the kinematic track, speed and angular speed curve of the material under the revolution of five set electric motors, the best motor revolution of the material kinematic characteristics and the interval between the motor speeds in the late test were obtained. A screening efficiency test was conducted at the interval of the manufactured test equipment and the verification was conducted on the simulation results. The result showed that when the material kinematic characteristics were in optimum, a max interval of the motor speed obtained from the simulation was 600 ～ 1 200 r/min. After the test conducted at the interval, the screening effect obtained within a motor speed ranging from 960 ～ 1 020 r/min was best and the simulation results could tally with the test results. The study could provide a new method to design the screen equipment and could provide an important basis to the late study.
Abstract：
During the coal cutting process of the cutters on the coal shearer, due to the high compressed stress, shearing force and dynamic load, the cutter could not realize a high efficient coal cutting and others of the coal shearer. A stress detection method of the cutter on the coal shearer was provided based on the strain sensor. The detection method was to conduct the real time detection on the cutter stress during the coal cutting process of the coal shearer with a method to stick the strain gauges on the cutters and a stress variation curve of the cutter could be real timely displayed. The test results showed that during the coal cutting period of the coal shearer, the stressed variation curve of the cutter could actually reflect the cutter stressed and the max X directional force of the cutter 1-1 selected would be about 0.70 kN. The max Y directional force value would be 1.72 kN. The max Z directional force value would be 4.16 kN and the torque of the cutter 1 would be 0.59 kN·m. In consideration of the influences of the error and related random factors, the test results closed to the related theoretical calculation value could realize the stress detection of the cutter. The study could realize the pre-judgement on the wear degree and the failure status of the cutter on the coal shearer, could timely found and replace the failure cutter and would have the important significances to improve the work efficiency and service life of the cutting head on the coal shearer.
During the coal cutting process of the cutters on the coal shearer, due to the high compressed stress, shearing force and dynamic load, the cutter could not realize a high efficient coal cutting and others of the coal shearer. A stress detection method of the cutter on the coal shearer was provided based on the strain sensor. The detection method was to conduct the real time detection on the cutter stress during the coal cutting process of the coal shearer with a method to stick the strain gauges on the cutters and a stress variation curve of the cutter could be real timely displayed. The test results showed that during the coal cutting period of the coal shearer, the stressed variation curve of the cutter could actually reflect the cutter stressed and the max X directional force of the cutter 1-1 selected would be about 0.70 kN. The max Y directional force value would be 1.72 kN. The max Z directional force value would be 4.16 kN and the torque of the cutter 1 would be 0.59 kN·m. In consideration of the influences of the error and related random factors, the test results closed to the related theoretical calculation value could realize the stress detection of the cutter. The study could realize the pre-judgement on the wear degree and the failure status of the cutter on the coal shearer, could timely found and replace the failure cutter and would have the important significances to improve the work efficiency and service life of the cutting head on the coal shearer.
Abstract：
Large gas reserves are trapped in the coals of the Middle Jurassic Walloon Subgroup in the Surat Basin. In order to correctly understand the accumulation characteristics, the research means such as sedimentology, geostatistics and natural gas geochemistry are used synthetically to study the sedimentary environment, structural characteristics, coal petrology and quality, origin of gas and models of gas accumulation. The research results show that the coal seams in Walloon subgroup are deposited in the river floodplain of meandering river and the marsh of meandering river delta plain, the coal has the characteristics of low degree of evolution, high ash content and small change in macerals. High permeability and high Langmuir pressure are the prominent characteristics of coal reservoir. Structure transfer zone has an important influence on reservoir permeability. The gas content with the Walloon Subgroup coals is low, and it is most likely to be dominantly secondary biologic gas，thermogenic gas also act to increase gas contents. Coalbed methane accumulation type varies from regions and formations that the Juandah Coal Measures in the northern syncline area is hydrodynamic seal type, the Taroom Coal Measures in Undulla nose zone and some part of the eastern slope is an anticline-water drive sealing type.
Large gas reserves are trapped in the coals of the Middle Jurassic Walloon Subgroup in the Surat Basin. In order to correctly understand the accumulation characteristics, the research means such as sedimentology, geostatistics and natural gas geochemistry are used synthetically to study the sedimentary environment, structural characteristics, coal petrology and quality, origin of gas and models of gas accumulation. The research results show that the coal seams in Walloon subgroup are deposited in the river floodplain of meandering river and the marsh of meandering river delta plain, the coal has the characteristics of low degree of evolution, high ash content and small change in macerals. High permeability and high Langmuir pressure are the prominent characteristics of coal reservoir. Structure transfer zone has an important influence on reservoir permeability. The gas content with the Walloon Subgroup coals is low, and it is most likely to be dominantly secondary biologic gas，thermogenic gas also act to increase gas contents. Coalbed methane accumulation type varies from regions and formations that the Juandah Coal Measures in the northern syncline area is hydrodynamic seal type, the Taroom Coal Measures in Undulla nose zone and some part of the eastern slope is an anticline-water drive sealing type.
Abstract：
Huanglong Jurassic coal field belongs to the typical low-rank CBM-bearing zone.Coal exploration data shows that there are certain exploration potentials of CBM in the west,but the condition of CBM reservoir formation is not clear.Based on the above,this paper studied the CBM reservoir forming conditions in the western area of Huanglong Coalfield from three aspects:CBM geology,coal reservoir characteristics and gas reserving condition,taking Linbei area of Yonglong Mining Area in the west of Huanglong Coalfield as an example.The main controlling factors of CBM reservoir formation in the study area were analyzed.The results showed that the Yan’an Group in western area of Huanglong Coalfield was characterized by low coal metamorphism,thick coal seam,moderate burial depth and good gas bearing property,but the permeability of coal reservoir was poor.The CBM enrichment was mainly affected by the depth of burial and hydrodynamic conditions,and the influence of structure and cap layer was small.The depth of 500～700 m was the best depth of coalbed formation in the study area.In the late period of coal formation,the Yanshan movement was affected by many stages of tectonic movement.The original biogenic gas and thermogenic gas were dissipated.Since the Cenozoic,the coalbed had received shallow surface water and atmospheric precipitation,and received secondary biogas was the key to CBM accumulation.The formation of CBM reservoirs in the study area was typical of the late-stage biotallogenetic accumulation model of basin-margin.
Huanglong Jurassic coal field belongs to the typical low-rank CBM-bearing zone.Coal exploration data shows that there are certain exploration potentials of CBM in the west,but the condition of CBM reservoir formation is not clear.Based on the above,this paper studied the CBM reservoir forming conditions in the western area of Huanglong Coalfield from three aspects:CBM geology,coal reservoir characteristics and gas reserving condition,taking Linbei area of Yonglong Mining Area in the west of Huanglong Coalfield as an example.The main controlling factors of CBM reservoir formation in the study area were analyzed.The results showed that the Yan’an Group in western area of Huanglong Coalfield was characterized by low coal metamorphism,thick coal seam,moderate burial depth and good gas bearing property,but the permeability of coal reservoir was poor.The CBM enrichment was mainly affected by the depth of burial and hydrodynamic conditions,and the influence of structure and cap layer was small.The depth of 500～700 m was the best depth of coalbed formation in the study area.In the late period of coal formation,the Yanshan movement was affected by many stages of tectonic movement.The original biogenic gas and thermogenic gas were dissipated.Since the Cenozoic,the coalbed had received shallow surface water and atmospheric precipitation,and received secondary biogas was the key to CBM accumulation.The formation of CBM reservoirs in the study area was typical of the late-stage biotallogenetic accumulation model of basin-margin.
Abstract：
In order to study the enrichment characteristics of shale gas in Permian Shanxi Formation at the west area of Tianjin,in combination with the previous information from each system of petroleum oil,coal and local mine industry and based on the test data of collected sample test,a comprehensive study was conducted on sediment distribution law of carbonaceous shale in Permian Shanxi Formation in the southwest area of Tianjin. The GIS means and the multi layer fuzzy comprehensive judgement method were applied to evaluation on the study region. The study results showed that within the study region,the carbonaceous shale in Permian Shanxi Formation was thick,the organic matters type was Type Ⅲ,the abundance was high,the pore was well developed,but the permeability was poor. The contents of quartz,feldspar and other brittle minerals were over 30%. In comparison with the marine phase carbonaceous shale mainly with quartz,the contents of brittle minerals was low and was not favorable to fracturing. The shale gas favorable exploration area was located in the south area of Wangkouzhen-Liangtouzhen-Jinghaizhen line and the comprehensive evaluation value was over 0.61 and could be the excellent favorable development zone.
In order to study the enrichment characteristics of shale gas in Permian Shanxi Formation at the west area of Tianjin,in combination with the previous information from each system of petroleum oil,coal and local mine industry and based on the test data of collected sample test,a comprehensive study was conducted on sediment distribution law of carbonaceous shale in Permian Shanxi Formation in the southwest area of Tianjin. The GIS means and the multi layer fuzzy comprehensive judgement method were applied to evaluation on the study region. The study results showed that within the study region,the carbonaceous shale in Permian Shanxi Formation was thick,the organic matters type was Type Ⅲ,the abundance was high,the pore was well developed,but the permeability was poor. The contents of quartz,feldspar and other brittle minerals were over 30%. In comparison with the marine phase carbonaceous shale mainly with quartz,the contents of brittle minerals was low and was not favorable to fracturing. The shale gas favorable exploration area was located in the south area of Wangkouzhen-Liangtouzhen-Jinghaizhen line and the comprehensive evaluation value was over 0.61 and could be the excellent favorable development zone.
Abstract：
In order to mine a Ji Formation coal resources threatened by the Permo- Carboniferous karst water in No. 11 Mine of Pingdingshan Tian’an Coal Company Limited, in combination with the hydrogeologic condition of the mine karst water, the karst development law and the passed year hydrologic information, the paper had an analysis on the mine water filling condition and the distribution law of the karst cracking zone in No. Ji Formation seam and a determination on a method combined with a shallow depth integrated discharging, a deep depth local discharging and local curtain grouting. With an industrial trial of draining lane and draining hole engineering,local curtain grouting and drainage engineering,and local working face waterproofing engineering, the correctness of the combined method was verified. The trial results showed that with a long term comprehensive water prevention and control, By the end of 2016,the water pressure dropped to 0.1 MPa, the threats of the karst water from the seam floor were eliminated and a safety mining was realized.
In order to mine a Ji Formation coal resources threatened by the Permo- Carboniferous karst water in No. 11 Mine of Pingdingshan Tian’an Coal Company Limited, in combination with the hydrogeologic condition of the mine karst water, the karst development law and the passed year hydrologic information, the paper had an analysis on the mine water filling condition and the distribution law of the karst cracking zone in No. Ji Formation seam and a determination on a method combined with a shallow depth integrated discharging, a deep depth local discharging and local curtain grouting. With an industrial trial of draining lane and draining hole engineering,local curtain grouting and drainage engineering,and local working face waterproofing engineering, the correctness of the combined method was verified. The trial results showed that with a long term comprehensive water prevention and control, By the end of 2016,the water pressure dropped to 0.1 MPa, the threats of the karst water from the seam floor were eliminated and a safety mining was realized.
Abstract：
In order to seal FS5-1 water inrush hole in Taran Gaole Mine and also prevent the subsidence and failure of the roofs in the drilling site and the surrounding water inrush gateway occurred in the grouting process,with the sectional grouting and water sealing method in the hole applied,an annular rubber packer was set 24.2 m location of the initial water inrush level in the hole. Thus the water in the hole was divided into upper and low sectional sections and there was an ø63.5 mm×8.0 mm pressure released steel pipe set in the internal ring of the packer. When full water drainage and pressure releasing made with the water released steel pipe,a low pressure grouting was conducted in the low section of the hole and the water drainage channel in the roof of the mine gateway. Then the pressure released pipe was applied to the high pressure grouting in the upper section of the hole and the water bearing strata and the water inrush hole was successfully sealed. The study results showed that the pressure released steel pipe was set at the initial water inrush location in the hole with the drilling rig. A method to set an annular rubber packer at the end of the steel pipe could effectively divide the grouting in the hole into two sections. During the pressure releasing,a low pressure grouting would not only reach the predicted grouting effect and could ensure the safety roof of the water inrush gateway. Therefore when the roof was broken,a good control effect of the water inrush hole would be in the water inrush hole. Meanwhile,the method could be applied to unconsolidate the pipe or the consolidation was failure and to consolidate the pipe or the water sealing under the condition of the water inrush.
In order to seal FS5-1 water inrush hole in Taran Gaole Mine and also prevent the subsidence and failure of the roofs in the drilling site and the surrounding water inrush gateway occurred in the grouting process,with the sectional grouting and water sealing method in the hole applied,an annular rubber packer was set 24.2 m location of the initial water inrush level in the hole. Thus the water in the hole was divided into upper and low sectional sections and there was an ø63.5 mm×8.0 mm pressure released steel pipe set in the internal ring of the packer. When full water drainage and pressure releasing made with the water released steel pipe,a low pressure grouting was conducted in the low section of the hole and the water drainage channel in the roof of the mine gateway. Then the pressure released pipe was applied to the high pressure grouting in the upper section of the hole and the water bearing strata and the water inrush hole was successfully sealed. The study results showed that the pressure released steel pipe was set at the initial water inrush location in the hole with the drilling rig. A method to set an annular rubber packer at the end of the steel pipe could effectively divide the grouting in the hole into two sections. During the pressure releasing,a low pressure grouting would not only reach the predicted grouting effect and could ensure the safety roof of the water inrush gateway. Therefore when the roof was broken,a good control effect of the water inrush hole would be in the water inrush hole. Meanwhile,the method could be applied to unconsolidate the pipe or the consolidation was failure and to consolidate the pipe or the water sealing under the condition of the water inrush.
Abstract：
In order to study surface deformation law of thick coal seam mining when the mining depth and mining height was variable,double factors of mining depth,mining thickness and small buried depth,thickness of No.11401 to No.21601(up)two working face on the surface movement deformation field measurement were analyzed in Huangyuchuan Mine .The results showed that No.21601(up)working face on the earth’s surface deformation degree was greater than No.11401 working face.After two faces full mining surface subsidence value was approximately equal than the reciprocal of the ratio of the two working faces base mining.The same geological conditions the mining ratio concept could be used to measure surface deformation damage evaluation of thick coal seam mining,the base was small surface deformation damage seriously.When the mining ratio increased,the surface deformation accordingly reduced.The end use of indoor physical simulation experiment to simulate the same deep effect of surface deformation rule of thick coal seam mining,the reasonahility of conclusion was verified,the prediction of thick coal seam mining ground surface deformation and evaluation provided the reference.
In order to study surface deformation law of thick coal seam mining when the mining depth and mining height was variable,double factors of mining depth,mining thickness and small buried depth,thickness of No.11401 to No.21601(up)two working face on the surface movement deformation field measurement were analyzed in Huangyuchuan Mine .The results showed that No.21601(up)working face on the earth’s surface deformation degree was greater than No.11401 working face.After two faces full mining surface subsidence value was approximately equal than the reciprocal of the ratio of the two working faces base mining.The same geological conditions the mining ratio concept could be used to measure surface deformation damage evaluation of thick coal seam mining,the base was small surface deformation damage seriously.When the mining ratio increased,the surface deformation accordingly reduced.The end use of indoor physical simulation experiment to simulate the same deep effect of surface deformation rule of thick coal seam mining,the reasonahility of conclusion was verified,the prediction of thick coal seam mining ground surface deformation and evaluation provided the reference.
Abstract：
In order to obtain fly ash with high desulfurization activity, in combination with scanning electron microscope(SEM),particle size analyzer, X-ray diffractometer(XRD),X-ray photoelectron spectrometer(XPS),chemical titration and other characterization methods, the dropper tube furnace was used to study the phase morphology, chemical components of fly ash and active CaO content obtained from pulverized coal combustion with different combustion temperatures. The influence law of coal combustion temperature on the characteristics of fly ash was investigated. The results showed that the combustion temperature had significantly affected on the phase morphology of fly ash, chemical composition, sulfur fixation rate and the content of active calcium oxide. With the temperature increased, the number of irregular shape particles gradually decreased, and particle size increased, the contents of CaO and Ca(OH)2 increased, the content of SO2 showed a trend of rise before they were gentle, the content of active calcium oxide increased gradually, which could effectively improve the fly ash as desulfurizer desulfurization of potential. By comprehensive analysis, the temperature about 800 ℃ was the best combustion conditions.
In order to obtain fly ash with high desulfurization activity, in combination with scanning electron microscope(SEM),particle size analyzer, X-ray diffractometer(XRD),X-ray photoelectron spectrometer(XPS),chemical titration and other characterization methods, the dropper tube furnace was used to study the phase morphology, chemical components of fly ash and active CaO content obtained from pulverized coal combustion with different combustion temperatures. The influence law of coal combustion temperature on the characteristics of fly ash was investigated. The results showed that the combustion temperature had significantly affected on the phase morphology of fly ash, chemical composition, sulfur fixation rate and the content of active calcium oxide. With the temperature increased, the number of irregular shape particles gradually decreased, and particle size increased, the contents of CaO and Ca(OH)2 increased, the content of SO2 showed a trend of rise before they were gentle, the content of active calcium oxide increased gradually, which could effectively improve the fly ash as desulfurizer desulfurization of potential. By comprehensive analysis, the temperature about 800 ℃ was the best combustion conditions.
Abstract：
The traditional Group Contribution method and Semi-empirical Correlation do not consider the interaction of group bonds and lack of calculation methods for the critical properties of heavy distillates in direct coal liquefaction oil(DCLO).So Artificial Neural Network and Group Bond Contribution Coupled Model(ANN-GBC)is constructed to predict critical properties of DCLO.Three layer network structure is adopted,with 45 group bonds and atmospheric boiling point of DCLO,a total of 46 as the number of neurons in the input layer of ANN-GBC Model,the optimum number of neurons in the hidden layer is determined to be 40 by the difference method,and the critical properties is used as the output layer.The correlation between the critical properties of 15 narrow fractions of DCLO and their molecular structure are studied.The critical properties of 20 model compounds are checked and validated by ANN-GBC Model,the relative error between the calculated value and the theoretical deviation is below 2.5%,and the correlation coefficient is 0.999 69.The results show that ANN-GBC Model has good function of simulating and accurately identifying the isomer.The critical temperature and critical volume of DCLO increase with the increase of distillation cutting temperature,and the critical pressure increase firstly and then decreased with the increase of cutting temperature.The results of model prediction and semi empirical correlation are basically the same,and the content difference of different components in each narrow fractions leads to the jump of individual results.The ANN-GBC Model not only reveals the quantitative relationship between the critical properties of DCLO and the molecular structure,but also provides a new and effective method for the prediction of the critical properties of other complex systems.
The traditional Group Contribution method and Semi-empirical Correlation do not consider the interaction of group bonds and lack of calculation methods for the critical properties of heavy distillates in direct coal liquefaction oil(DCLO).So Artificial Neural Network and Group Bond Contribution Coupled Model(ANN-GBC)is constructed to predict critical properties of DCLO.Three layer network structure is adopted,with 45 group bonds and atmospheric boiling point of DCLO,a total of 46 as the number of neurons in the input layer of ANN-GBC Model,the optimum number of neurons in the hidden layer is determined to be 40 by the difference method,and the critical properties is used as the output layer.The correlation between the critical properties of 15 narrow fractions of DCLO and their molecular structure are studied.The critical properties of 20 model compounds are checked and validated by ANN-GBC Model,the relative error between the calculated value and the theoretical deviation is below 2.5%,and the correlation coefficient is 0.999 69.The results show that ANN-GBC Model has good function of simulating and accurately identifying the isomer.The critical temperature and critical volume of DCLO increase with the increase of distillation cutting temperature,and the critical pressure increase firstly and then decreased with the increase of cutting temperature.The results of model prediction and semi empirical correlation are basically the same,and the content difference of different components in each narrow fractions leads to the jump of individual results.The ANN-GBC Model not only reveals the quantitative relationship between the critical properties of DCLO and the molecular structure,but also provides a new and effective method for the prediction of the critical properties of other complex systems.
Abstract：
Aiming at the serious erosion wear on components of coal water slurry valve with high pressure during coal gasification, based on the fluid physical parameters, operation conditions and three-dimensional flow structure of coal water slurry valve, the mathematical model and calculation method are constructed to describe the process of flashing, particles movement and erosion wear. Then the numerical simulation on the erosion wear in the valve is carried out. The results show that severe erosion wear locate on the top of valve spool and the entrance of valve bushing. Among them, the maximum erosion rate occurs on the top surface of valve spool. The numerical results agree well with the actual failure instance, thus the accuracy of calculation model and method is verified. The research results can provide the reference for failure analysis and structural optimization of the similar valves.
Aiming at the serious erosion wear on components of coal water slurry valve with high pressure during coal gasification, based on the fluid physical parameters, operation conditions and three-dimensional flow structure of coal water slurry valve, the mathematical model and calculation method are constructed to describe the process of flashing, particles movement and erosion wear. Then the numerical simulation on the erosion wear in the valve is carried out. The results show that severe erosion wear locate on the top of valve spool and the entrance of valve bushing. Among them, the maximum erosion rate occurs on the top surface of valve spool. The numerical results agree well with the actual failure instance, thus the accuracy of calculation model and method is verified. The research results can provide the reference for failure analysis and structural optimization of the similar valves.
Abstract：
In order to seek a kind of coal gasification process without any special requirements,such as the type of coal or the ratios of the water vapour and oxygen,the low-temperature low-pressure saturated steam was used as the single gasification agent,and microwave was used as an entrained flow auxiliary heat source,absorbing agent was used as the heat transfer medium for the gasification of anthracite,bituminous and lignite.The results were as follows,under optimum conditions of the orthogonal experiment,75 g anthracite was mixed with MnO2-based absorbing agent in accordance with the mass ratio of 3∶1.The mixture was gasified in the 800 W microwave power when the 158.7 ℃ steam flow was 2.2 L/s,and the stable gasification temperature was 1 966 ℃,the complete gasification time was 10.7 s.The microwave energy consumption per unit mass was only 114.2 kJ/kg,the content of hydrogen and carbon dioxide in the water gas made from the above conditions was 94.1%.When the stable gasification temperature was 1 742 ℃,the CO2 concentration was only 0.8%.A high temperature environment effectively inhibited the converting reaction.The composition-ratio curves of three typical water gas were rotated clockwise order by CO、CO2、N2、H2、O2、CH4.The small diameter gasification reactor had a faster speed and lower microwave power consumption.
In order to seek a kind of coal gasification process without any special requirements,such as the type of coal or the ratios of the water vapour and oxygen,the low-temperature low-pressure saturated steam was used as the single gasification agent,and microwave was used as an entrained flow auxiliary heat source,absorbing agent was used as the heat transfer medium for the gasification of anthracite,bituminous and lignite.The results were as follows,under optimum conditions of the orthogonal experiment,75 g anthracite was mixed with MnO2-based absorbing agent in accordance with the mass ratio of 3∶1.The mixture was gasified in the 800 W microwave power when the 158.7 ℃ steam flow was 2.2 L/s,and the stable gasification temperature was 1 966 ℃,the complete gasification time was 10.7 s.The microwave energy consumption per unit mass was only 114.2 kJ/kg,the content of hydrogen and carbon dioxide in the water gas made from the above conditions was 94.1%.When the stable gasification temperature was 1 742 ℃,the CO2 concentration was only 0.8%.A high temperature environment effectively inhibited the converting reaction.The composition-ratio curves of three typical water gas were rotated clockwise order by CO、CO2、N2、H2、O2、CH4.The small diameter gasification reactor had a faster speed and lower microwave power consumption.
