Abstract:By means of similar material simulation and numerical simulation, simulated mining of No. 8 and No. 5 coal seams in Bai Zi coal mine. Similar simulation results show that the bottom plate pressure of the No. 8 coal seam is fluctuating by the stress value of the original rock of 2.67MPa, and the coal pillars remain stable after the mining of No.8 coal seam. In the case of No.5 coal seam, the maximum abutment pressure of coal floor is 3.92MPa, which is much lower than that of coal pillar 11.8MPa. The numerical simulation shows that the vertical stress of the lower coal pillar is obviously reduced when the No. 5 coal seam is mined, and the decompression zone is formed in the coal mining area. During the upward mining of No. 5 coal seam, the pillar remained in No. 8 coal seam remained stable.

This paper mainly analyzes and studies the safety of mining under river, First of all, through regional exploration, the water abundance, surface soil thickness, coal seam and structure are explored; Based on theoretical calculation and drilling measurement, the height of water flowing fractured zone is determined; through the analysis of aquifer and impermeable layer, the amount of precipitation and the amount of water inflow in the mine, the influence of river water on underground mining is finally determined,It has important guiding significance for mine under River Mining. At the same time, the ground subsidence is simulated by using the surface subsidence software, Providing guidance for the mine of the ground river course.

In order to realize the deep well cooling technology of coal mine, the feasibility analysis was carried out on the vaporization and cooling of mixed liquid liquid roadway in Zhaolou coal mine. According to the cooling capacity of the mine, the demand for the liquid oxygen and liquid nitrogen mixed liquid required for the mine is calculated, and the gas produced and the equipment needed are analyzed. The feasibility of vaporization and cooling of liquid oxygen liquid nitrogen mixed liquid roadway is preliminarily explained.

This article Combined with the MicroStation software development platform of Bentley companies in the United States , using the MDL secondary development method, combined with the complexity of geological conditions of special coal mine, through the establishment of topography and graphics library, drilling database, database structure, etc. forming the ground terrain mesh surface, the three-dimensional borehole columnar body, structure grid, using data and graphics functions,which mainly from the study of coal mine process and key points of 3 d geological modeling, discusses the suitable a set of the concept for 3 d geological modeling , shows the effect of 3 d geological modeling and visualization. Modeling of 3 d mine and play an important role in the development of digital mine.

In order to increase the early-warning accuracy of rock burst monitoring and early warning, the current situation and problems of rock burst multi-parameter monitoring and early warning are analyzed. Besides, the rock burst multi-parameter monitoring and early-warning platform is proposed and developed. Finally, the timeliness of this platform is verified by engineering application. This investigation shows this platform can fully mine the information of monitoring data, overcome the shortcomings of relatively independent monitoring indexes, poor online joint monitoring effects and difficult multi-parameter joint monitoring. Furthermore, this platform can integrate and analyze all kinds of monitoring data in one time-space dimension to increase rock burst early-warning accuracy and timeliness. The result can provide a new method for rock burst monitoring and warning in coalmine.

In the lower-chord panel point of Shanxi Pinglu coal handling trestle pipe truss, outer ring plate and the vertical web rod H-Beam of the wind braced truss connect, its structure and the bearing?condition?are more complicated, which is beyond the scope of the relevant provisions of the existing national specification . In order to evaluate the static performance of such nodes, the full scale model static test is carried out, the elastic-plastic?finite?element?method is used to numerically simulate, and the stress development, deformation process and failure mode are analyzed during the loading process. The results show that the node has good carrying capacity and can meet the requirements of engineering design. The weak part of the node area is in joints between pressure pipe and outer ring, so we should strengthen measures.

Through the sliding movement of the constant resistance body, the anchor bolt with constant resistance and large deformation can achieve constant working resistance and adapt to large deformation of the surrounding rock, and by analysising the principle of the anchor bolt with constant working resistance and large deformation, the constitutive equation of anchor bolt with constant working resistance and large deformation supportting system was established, then it was applied in hengyuan coal mine Ⅱ632 transportation lane to suppot the tunnel using cutting roof to release the pressure. Monitoring results show: the deformation amount of the anchor bolts system with constant resistance and large deformation is 548mm, The constant working resistance can still be maintained after the effect of the advance mining pressure and the effect of the mining pressure, The average value is 328.4kN. When the roof accumulatively sinks 371.7mm, the anchor cable with constant resistance and large deformation will absorb energy through its structural deformation to maintain the overall stability of the roadway roof, while the ordinary anchor cable is pulled off because the deformation of the supporting system exceeds its maximum tensile capacity.

Abstract：Thick coal seam through a small coal mine on the formation, the roof structure of upper formation is very complex, and the mining of the lower coal seam may have a significant adverse impact, which brings great influence for support of the mining roadway below. Aiming at the complexity of the roof structure of 8101 integrated mine roadway, roadway characteristics are classified, and proposes a dynamic roadway timbering principle. The optimization and selection of support parameters are carried out by means of theoretical analysis and numerical simulation, finally determine the roadway using scheme with cable anchor support and shed support supplemented by the "supporting dynamic partition". Field practice shows that the deformation of surrounding rock in a reasonable range, meet the requirements of safe production, roadway research results can provide the reference for the similar condition.

In order to support the working surface by means of the temporary support device, the working resistance of the temporary support device is measured and recorded by using the electronic pressure automatic recorder, and the working pressure of the temporary support device is measured, The reliability, application and reliability of the supporting device are verified by the analysis of the operability, reliability and adaptability of the supporting device.

Based on the background of Xing Sheng coal mine 0913 wind tunnel excavating, using numerical simulation method, analyzed the effect under the condition of narrow coal pillar along gob roadway surrounding rock control technology in mining, put forward the scientific supporting scheme, control the attack mining goaf surrounding rock deformation along the working face effectively, alleviate the mining stress. 0913 working face return roadway in mining working face goaf roadway under the condition of significant technical and economic benefits, not only to the mine roadway under the condition of similar future brings valuable experience, and even the similar conditions to the surrounding mine coal face along goaf was to provide technical reference for valuable mining.

In order to reduce the dangers of safety production in coal mine from water flowing subsided column, the collapse column grouting reinforcemet is a very effective means. Based on the governance engineering of NO.2 collapse column in the 19108 working face Pingshuo Underground mine One, discussing the collapse column grouting reinforcement techniques, using the governance principles of “While construction, while analysis, while optimizing design”, puts forward the end of the grouting engineering standard and the governance effect testing method. The results show that:collapse column development characteristics is the premise of grouting reinforcement governance. Reasonable drilling layout and grouting parameter selection is the key technology of grouting reinforcement governance. Grouting to dilute before they are thick and grouting pressure increased gradually from 2 to 6 MPa. Inspection hole engineering quality inspection, the original exploration hole water yield and water quality analysis is the effect of effective testing method. Finally, 19108 working face safe passing 2 # collapse column after the governance.

Based on the measurement and analysis of the return air lane, this paper optimized the arrangement of transportation lane, which reduced the absolute number of hydraulic support need to be added or withdrew by 36 to 13; Put forward the bracket installation chamber achieved rapid adding hydraulic support, which reduced the operation time from 24 hours to 8-12 hours for adding one support; Put forward to using the rapid removing method with Pre-dug retreating channel withdraw the equipments, which reduced the influence of the production time by expected 10 days to 3-4 days, get the purpose of rapid adding or withdraw the hydraulic support in working face.

Abstract：Through the analysis of relevant literature review and geological data in Qian Jiaying mine.The geological tectonic factors are divided into five parts: buried depth contour, fault number, fault average drop, fault average length and fault density.By means of cluster analysis and analytic hierarchy process,five parts of geological structure factors are simplified,confirming the weights of geological structure factors at various levels in Qian Jiaying mine.Counting the index of gas outburst in different levels,combined with the gas dynamic phenomenon of -850m main cross cut area in Qian Jiaying mine,the critical value of gas outburst is to be 0.308 of geological structure in Qian Jiaying mine.This method quantifies the geological structural factors, and provides a way to analyze the geological structural factors.

Abstract: in order to ensure the drainage effect and achieve the purpose of saving material borehole, the borehole imaging ZKXG30 mine track detection device in internal characteristics of rock layer drilling peep, found above orifice small range rock fissures, most fissures, according to the development situation of drilling hole of rock fracture, the sealing method was improved and developed the metal push rod and the sealing tube fixing device, using a new process of sealing borehole in rock fissures period instead of sealing tube, and sealing of drainage effect compared with the entire sealing tube, also has good air tightness, no leakage, after a month drainage statistics, production parameters consistent with two kinds of drainage borehole sealing technology, can be widely used in gas under similar geological conditions.

In order to reveal the mechanism of the rock burst with Horizontal sectionTop Coal Caving in the steeply inclined thick coal seam, the geological conditions and mining conditions of the mine are taken as the object of the 5521-21 working face of Yaojie No.3 Mine. Based on the impulse power source, it is found that the superposition effect of static and dynamic load is the core of 5521-21 working face.The prevention and control measures of coal body pressure relief blasting, bottom coal pressure relief blasting, coal body large diameter drilling pressure relief and roof deep hole pre-splitting blasting are carried out, and good results are obtained through inspection.

The conveyor belt replacement of existing method is inefficient, high security risk, for a long time and other shortcomings. In this paper, we propose the program of the continuous belt replacing device is based on electromechanical liquid system. The drive source is hydraulically driven, and the transmission belt mechanism uses a three-stage crawler chassis. In addition, the structure and working principle of the device are expounded, the hydraulic system is simulated, and the performance parameters of pulling the belt and clamping circuit are acquired. The further experimental study of the belt replacing device is carried out to reflect the correctness of the simulation. The results show that, the clamping force provided by the clamping circuit is sufficient to allow the tracked chassis to clamp the belt. The pressure of the pulling belt system varies with the belt weight, and the speed of the belt replacing varies with the pump displacement. Meanwhile, for the time from the original 5 days or even more shortened to 3 days. In summary, the safety and efficiency of the continuous belt replacing device with using crawler drag are ensured.

There is a certain distance between the inclinometer and the drill bit, which makes it impossible to measure the borehole parameters directly. In the construction process of directional well of coalbed gas, there is a situation in which the straight section of the straight -steady-state two dimensional directional well is diagonally tilted, which makes the deflection point have a deviation angle and azimuth angle. Based on the field drilling engineering, this paper analyzes and summarizes the function relationship between the tool face and the change of hole drift angle and azimuth angle. This makes it possible to predict the trajectory accurately. A set of directional well trajectory control technology is proposed and verified in the construction of multi-well in the area.

In order to study the deformation law of the surrounding rock in gob-side entry retaining by roof cutting and pressure release in thick coal seams, in the engineering background of S1201-II seam face in Ningtiaota Mining, the deformation of the roof and floor in the roadway and the pressure distribution of the surrounding rock support were researched, through field measuring and FLAC 3D numerical simulation. The results show that the distribution law of the stability of the surrounding rock in the thick coal seam can be divided into three stages: pressure change zone, pressure stabilization zone and pressure stabilization zone. During the forward direction of the working face, the rated value was 9.19MPa, the stability value was 8.47 MPa, the supporting pressure peak point away from the coal wall 6~9 m;the lagging working surface 200m was identified as conservative safe location, after this position, all the temporary support equipment can be withdrawn.As for within lagging working surface 90m surrounding rock deformation was obvious, this scope was the key support area to ensure production safety. The successful application of the research results in the actual engineering of the site provides a useful reference for the popularization and application of gateway retained along goaf Technology with roof breaking and pressure releasing in the thick coal seam.

Overburden movement and mechanics characteristics of steeply dipping large mining height face are more complex, it’s necessary to study overburden movement and mechanics character. Based on numerical simulation and field measurement, overburden movement and mechanics are analyzed. The results show that higher and lower strata of different area show different displacement forms - lower strata displacement profile shifted to the lower face area, higher strata displacement profile shifted to the upper face area, vertical displacement and top pressure of middle and upper face area are bigger than lower area, the upper and lower end are easy to form stress concentration zones in different positions, and the stress at the lower end is concentrated near the roof area, and the stress at the upper end is concentrated near the floor area, The overburden movement and the top pressure are proportional to the mining height.

Taking a ShanXi mine as the engineering background , mathematical expressions about dynamic response of cracked roof at pre-stable state is obtained through vibrating mechanics analysis. Several factors—basic top collapse step, thickness of coal seam, damping coefficient of hydraulic support and rocking elasticity of waste rock—are discussed in order to knew the influence of them on dynamic response of cracked roof. The results show that the vibration time of roof initial collapse is longer 0.25s than that of roof cycle collapse, and the vibration energy consumes 85% in 0.5s; maximum vibration displacement of roof will increase 10mm with collapse step increasing 10m, and reduce 7mm with coefficient of hydraulic support increasing one unit; dynamic response of cracked roof will be significantly lower when coal seam thickness of mining is less than 4m, and elastic modulus of waste rock is greater than 3.5GPa.

According to the characteristics of the formation and the logging data of the boreholes in Hongqinghe coal mine, the strata in the study area were re-divided, and the sedimentary law of the strata was studied by combining with the mark of the sedimentary facies. The results showed that the 3th section of Yanan formation was mainly composed of delta plain subfacies, developing three near the north-south rivers and two near the north-east rivers with the ratio of sandstone thickness to formation thickness greater than 0.4 at distributary channel, and the 1st and 2nd section of Zhiluo formation were mainly composed of braided river and riverbed and flood plain of sedimentary subfacies developing several near the northwest-southeast rivers with the ratio of sandstone thickness to formation thickness between with 0.6 and 0.8 at river center. The results can provide a basis for the evaluation of water abundance later.

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Taking the BBD3854 coal mill of 660-MW unit in Hequ power plant in Shanxi as the research object,the dynamic mathematical model is built to approximate the real system, and the model is verified by real data. In order to enrich the fault knowledge base and research on the fault diagnosis,the real fault of the pulverizing system is simulated, and the variation rule of the characteristic parameters under different faults is excavated.A new method of fault diagnosis based on the fault scaling factor search technique is proposed by summarizing the similarity rules of different severity faults.This method only needs to carry on the off-line training to each kind of fault in the typical fault sample,this makes the fault diagnosis and identification faster and more stable.The effectiveness of the proposed method is verified by an example of an auxiliary coal pulverizer.

In order to study the difference between rotate speed and blade incidence adjustment of contra-rotating auxiliary fan, numerical simulation are carried out at different working conditions by using Fluent. And simulation models are verified by experiment. Pressure, volume, efficiency and shaft power at different pipe distance are analyzed. Results show, both ways can change fan’s output ability, but they have different essence, efficiency decreases as blade incidence reduces, while doesn’t change by speed; combing two means of adjustment can realize high efficiency and energy saving operation.

Abstract: the mechanical properties of rock mining complex, not easy to realize the precise modeling of the drum, the drum design method established by the existing model cannot effectively ensure the actual loading performance of the drum, resulting in lack of shearer drum actual average loading performance of 60%, so the design method of roller working surface based on the field data is of great significance to research. The selection of work field loading performance more than 80% of the 500 sets of roller parameters as the research basis, put forward the pitch s and γ(blade pitch and diameter and cylinder diameter ratio) using two parameter design method, using curve fitting optimum range of blade pitch and legally obtained the calculation formula to establish the design method of double parameters shearer drum. With two kinds of methods are used to design Shandong Bu lian ta coal mine 4500 cylinder of the left and right roller, the contrast test was made in the face of the scene, the drum loading performance measured by dual parameter design method is about 85%, the existing design method of loading performance is about 70%. The results show that the two parameter design method based on the field data can effectively guarantee the actual coal loading performance of the drum.

Based on the fact that the production of gas wells in Hancheng mining area is quite different, in order to make clear the main factors of production control, three production models of single well are summed up on the basis of production data of Hancheng mining area,，Mode I: single peak –attenuation type，Mode II: single peak- stable type and Mode III: multi peak -discontinuous type. The characteristics of medium high yield wells, low producing wells and non producing gas wells are respectively represented . Based on the geological, structural and drilling data, the influencing factors of productivity model are analyzed from three aspects of coal seam thickness, gas content and permeability, It is considered that the thickness of coal seam has little influence on productivity characteristics, and the gas content and permeability condition are the main controlling factors. The structure and hydrogeological condition have important influence on the gas content in the area, and the overall preservation condition is superior. Besides the southeast edge and the shallow part, the gas content in the other areas is higher. The permeability is mainly affected by the coal structure and depth control, generally in the regions of fractured coal is of high permeability, pulverized coal, coal particle area is relatively low, and the permeability of the primary structure coal area by depth control. The results show that coalbed methane production is mainly controlled by structure. It controls gas content, hydrogeological characteristics, depth of formation and structure of coal. It is the key factor that affects the productivity of CBM well in this area.

Abnormal structures in coal measures strata are threatening the progress of mechanized coal mining and the safety of coal mine workers,chasms are the most common ones among them.In-seam Seismic Survey is an effective method to use the channel wave propagating in coal seam to finely investigate the abnormal structures of coal seam.To analyzing the influence of chasms on the channel wave is of great significance for prediction and location of chasms.In this paper, a three-dimensional coal-bearing strata model and a chasm model are established in comsol5.2. Using the Ricker wave with frequency of 200 Hz as the source excitation, channel wave signals carrying chasm information are obtained. The time-frequency analysis of the signals using the generalized S transform shows that the chasms will reduce the amplitude of the channel wave, resulting in the loss of partial frequency energy. When the gap of chasms is smaller than the thickness of coal , the dispersion curve will not be affected.

The dielectric response or dielectric loss of low-rank coal determines the feasibility and economic benefit of microwave heating. According to the propagation rule of microwave in dielectric, the quantitative relationship between microwave energy utilization efficiency and complex relative dielectric constant was derived, and two important parameters describing microwave energy utilization efficiency, microwave absorption coefficient and the average power density of dielectric loss, were derived. In this paper, the influence of coal properties and coal species on microwave dielectric response was studied based on four kinds of low-rank coal. The relationship between dielectric response parameters and microwave heating characteristics was also discussed. The results show that, the microwave absorption coefficient and the average power density of dielectric loss were only affected by their properties under the condition that microwave frequency was fixed and temperature changed little. Moisture and pyrite could help to promote the dielectric response of low-rank coal to microwave, and the particle size which was equal to or less than penetration depth had little effect on microwave dielectric response. The microwave radiation time in the low temperature stage was almost 50% of the total radiation time, that was, 50% of the total energy consumption. The dielectric response parameters of low-rank coal to microwave could reasonably explain the heating characteristics at this stage. Therefore, the dielectric response parameters had important guiding significance for the selection of coal, pyrolysis technology and equipment.

In order to protect the scarce coking coal resources in China, based In order to protect the scarce coking coal resources in China, based on China's coking coal resources reserve, development and utilization status and analysis of coking coal supply and demand relationship, we pointed out the problems in the development of China's coking coal industry, such as the shortage of resources reserves, the excessive exploitation of high-quality coking coal resources, the structural contradiction of output, the contradiction between large-scale blast furnace and shortage of resources; finally, put forward relevant development countermeasures and suggestions including increasing exploration efforts, further advances in structural reforms in the supply side, protective development and utilization, active exploitation and utilization of foreign resources.

In order to study the collision efficiency?between the bubbles in the pulp and the fine slime and its influencing factors in the process of flotation ,a numerical calculation method based on numerical simulation software FLUENT is presented ,then this method is used to simulate the bubble and particle collision behavior of different particle size, particle density, bubble diameter and turbulence intensity,the collision efficiency between bubbles and particles was calculated, and the effects of various factors on the collision efficiency of single bubble and coal particles were obtained.The results are as follows: particle size and bubble size are the main factors that affect the collision efficiency between bubble particles.With the increase of particle size, density and turbulence intensity, the collision efficiency increases.In the still water, the collision efficiency increases with the increase of bubble size;in turbulent flow, the collision efficiency decreases with the increase of bubble size.

This article describes the process of the shear spring，established flip-flop screen simplified mechanical model, get the formulas for the shear spring stiffness through the solution of the equations. The stress cloud and stress-strain curves under compressive conditions and shear conditions are obtained by numerical simulation. Spring stiffness and shear stiffness of shear compression is determined by universal tester, the influence of compression amount to shear stiffness is analyzed, provides theoretical basis for shear spring design calculations, selection and testing in future.

Abstract: Based on the CFD method, the single-phase flow of the cyclone-static microbubble flotation column was simulated by RSM turbulence model, the numerical simulation results were consistent with the PIV experimental results. On the basis of this, the effect of circulation flow rate and feeding mode on flow field in cyclone zone was researched. The results show that: with the increase of the circulating flow rate, the axial velocity and tangential velocity in the swirl inverted cone and column flotation zone are increased, when the circulation flow rate is constant, with the increase of the incident angle, the axial velocity gradually changes from "W" type to "U" type in the swirl inverted cone zone, the tangential velocity decreases with the angle of incidence, the axial velocity and tangential velocity in the column floatation zone are reduced, when the incident angle is 90 °, it decreases to 0 m/s, and the turbulent dissipation rate in the cyclonic reversal cone also increases with the incident angle. When the angle of incidence is low, increasing the angle increases the flotation probability of fine-grained and coarse-grained minerals, and the angle of incidence being the best at 60 °, continue increasing the incident angle, the way of mineralization will changes from cyclone to pipe flow, which is not beneficial to the cyclone zone to sort the particle by the difference in size and density, thereby reducing the separation efficiency.

In view of the common manual mechanical shift mode of coal mine explosion-proof hydraulic transmission vehicle, a set of automatic shift control system of explosion-proof hydraulic transmission vehicle is designed in this paper. First of all, it briefly introduces the structure of the hydraulic drive system of mining explosion-proof vehicles and the characteristics of each component. Based on the principle of the highest torque converter working efficiency, the best power shift rule is deduced. Then the mine explosion-proof automatic shift control system components and functions were introduced. Finally, the bench test confirms the practicability of this automatic shift control system and shift control strategy.

As the core power device of explosion-proof trackless rubber-tyred vehicle vehicle, the performance of explosion-proof diesel engine determines the dynamic performance and emission performance of the vehicle. The advanced explosion-proof electronic fuel system of the explosion-proof electronic control diesel engine can realize precise timing quantitative injection, the maximum injection pressure can reach 130 MPa. Integrated with the methane sensor, surface temperature sensor and other coal mine special requirements, reduce the diesel engine electrical protection system, reduce the complexity of the machine. To meet the requirements of coal mine explosion-proof, the emission performance of explosion-proof diesel engine is greatly improved to ensure the safe and clean production environment of coal mine.