Abstract: The ecology of the mining areas in western China is fragile, in where rich in coal and lack of water. The protection and utilization of water resources in coal mining is of great significance. Academician Gu Dazhao combined with more than 20 years of technical exploration and engineering practice of coal mine underground reservoir in Shendong mining area, the theoretical framework and technical system of coal mine underground reservoir with "guiding storage and use" as the core was proposed. Based on the construction experience of more than 30 underground reservoirs in Shendong mining area, the design concept of mining area-coal mine underground reservoir system of is studied. The design system composed of mining area-underground reservoir and roadway layout, dam design, reservoir capacity calculation, pipeline design, related chamber and equipment layout and safety monitoring system is constructed. The core technology of each system design is summarized, which is of great significance to the popularization of design of mining area-coal mine underground reservoir.

Based on the field measurement results of 122107 fully mechanized top coal caving face with large mining height in Cao Jiatan Coal Mine, the time of each working procedure and the operating rate of the working face system are systematically summarized. The main methods to optimize and ameliorate the technology of Cao Jiatan fully mechanized top coal caving face are put forward, Which, moderately increase the length of the working face to 350 m, increase the cutting depth of the coal shearer to 1.0 m, and increase the cutting speed of the shearer to 6~8 m/min; The time for support moving should be 15.5~17.3 s, the time for pushing the scraper forward should be 8.2~9.6 s, the time for pulling the scraper backward should be 8.1~10.2 s, the time for extending the fender should be 8.6~10.2 s, and the time for pulling the fender back should be 17.1~25.7 s. The coal drawing method should be adjusted to "double round of coal drawing in groups", so that the monthly output of the working face can reach 1.62~2.17 million tons, the annual output can reach 17.84 million t~23.9 million tons, and the mining efficiency will be 1.8~2.4 times of the current stage, These results are of great significance for optimizing mining technology and intelligent design.

By analyzing the temporal and spatial evolution law of mine pressure in the course of mine-like paste filling mining, the load-bearing evolution mechanism and characteristics of the temporary coal pillars and the filling body in the course of "mining-filling" are explained, Get the requirements for the ultimate strength of the backfill. Based on this, using the coal pillar strength theory and the empirical formula of the development height of the fracture zone, the reasonable range of the temporary coal pillar width, the development height of the fracture zone and the ultimate load of the filling body are calculated. Finally, the strength of the backfill was checked, and the width of the temporary coal pillar was verified and optimized by numerical simulation, and finally a reasonable width of the temporary coal pillar was determined.

In view of the isolation of the coordinated development and production system of coal and coalbed methane, the complexity of continuous design and the poor scientificity of traditional manual compilation, The definition methods of various process types such as surface drilling and extraction of coalbed methane, well construction and development, roadway preparation, coal mining in working face and underground drilling and extraction of coalbed methane throughout are studied. The spatial layout relation and time connection relation database are constructed. The intelligent design platform of production system is developed by using engineering queuing method, dynamic programming method and critical route method. While the process database is built, the construction progress bar chart is generated synchronously, which is convenient for engineers and technicians to check the mutual constraint relationship between various engineering tasks at any time. The project progress report is generated synchronously, and the dynamic statistical analysis of the report per unit production and single entry is realized. At the same time, it also integrates dynamic monitoring functions, including construction team monitoring, connection relationship monitoring, spatial relationship monitoring and key route monitoring. When time conflict, space conflict, connection relaxation, connection tension, construction idle, construction interleaving and other conflicts occur between tasks, the system will automatically alarm and , so as to provide quantitative data support for engineers and technicians to modify the connection system. The results show that the system innovatively expands the single isolated and static production system into a fully integrated and dynamic production system of the four systems of "pumping, construction, excavation and mining" of the whole mine. It can realize the systematic, digital and fine connection of coal and coalbed methane development, realizing the rational layout of coal and coalbed methane development space and orderly connection in time, help the integrated and coordinated development and production practice of coal and coalbed methane, and improve the informatization and intelligence level of mine production.

The design of coal preparation plants mostly adopts two-dimensional design mode, resulting in no BIM model asset accumulation in most coal preparation plants. In this paper, by building a BIM collaborative design platform, the concept of three-dimensional collaborative modeling is applied to the BIM model reconstruction of coal preparation plants based on design drawings, and a set of BIM model reconstruction mode of coal preparation plants with high efficiency and high quality is studied, It solves the problems that affect the modeling efficiency and modeling quality in the BIM model reconstruction of coal preparation plant in the design and construction stage, such as difficult work development, difficult cooperation and many collisions. It is suitable for application in engineering projects with BIM collision inspection, operation and maintenance management and other application requirements, which need to establish BIM model.

Sha qu gas power plant Project Ⅱ was officially put into operation in 2012, a number of field researches indicated that the project was unreasonable in plant ventilation and cooling water tank layout, which resulting that the unit output was far from reaching the design index requirements of 2MW, the comprehensive utilization of gas was insufficient, the technical and economic indicators were lower than expected. According to the project characteristics and field researches, this paper emphatically analyzes the main causes of insufficient output of gas generator unit, and provides targeted and feasible rectification measures, so as to provide reference for the later rectification of the project.

Coal mine shaft is a key part to ensure smooth production, and its deformation of surrounding rock to failure and damage is still one of the main forms that affect the safety of coal mine production. In view of the weathering, cracking and bulging deformation problems of the Jijianao inlet air shaft of Xinyuan Mine, the geological and production conditions and stress environment of the site were investigated in depth, and the damage factors were analyzed and concluded the complex regional stress distribution, the deteriorated rock conditions, the corrosion and weathering of the shaft walls and the unreasonable support method, and it is pointed out that the deterioration of surrounding rock strength in weak strata, the loss of well wall strength caused by well wall corrosion and weathering, and the unreasonable support method are the main reasons for the deformation of the well wall. According to the field conditions, the changes of the stress environment around the shaft are analyzed in detail, including the increase of the additional stress the horizontal force on the shaft wall. The increase of the additional stress is due to the subsidence of the formation caused by the hydrophobicity of the aquifer, and the increase of the horizontal stress is caused by the attenuation of the rock cohesion caused by the deformation of the surrounding rock; In terms of the strength and deformation of the shaft enclosure structure, through the establishment of the mechanical model of the shaft structure, it is concluded that the damage condition of the shaft is that the horizontal force of the shaft wall exceeds its allowable stress limit value. Deformation and damage of the shaft may occur in the rock mass, and two specific directions for repairing the shaft and maintaining its safety are proposed accordingly. On the premise of synthesizing the advantages and disadvantages of various repair technologies, the comprehensive repair plan is proposed including grouting, prestress grouting anchor cable and shotcrete, and then detailed grouting and prestressed anchor cable support parameters are designed, and the construction process of shaft wall repair is formulated. Finally, a long-term deformation observation was implemented after the project was carried out on site, and the results showed that this scheme could maintain the shaft safety and stability.

View of the engineering problems that the coal roadway of Jurassic isolated island working face in Northwest mining area is seriously broken, the deformation speed is fast and the on-site support is difficult under the action of high stress, the transportation chute of zf303 isolated island working face in Xiagou coal mine of Shaanxi Huabin group is taken as the research object, and the methods of theoretical analysis, borehole peeping and industrial test are adopted, The effects of geological factors and support factors are analyzed, the surrounding rock control scheme of "bolt grouting reinforcement" is designed, and the grouting reinforcement parameters are optimized based on theoretical analysis and field practice. The results show that the unique properties of Jurassic coal seam combined with unreasonable initial support parameters are the main reasons for the difficulty of zf303 transportation channel support; The range of 0 ~ 2m in the surrounding rock of zf303 transport channel is general fracture area, the range of 2 ~ 4m is fracture development area (plastic failure area), and the range of 4 ~ 10m is complete area. There is separation between coal seam and direct roof transition area; After adopting "bolt grouting reinforcement" in zf303 transportation channel, the deformation of surrounding rock is significantly reduced and the stability of roadway is effectively maintained.

To solve large floor drum up deep soft rock roadways deformation control problem, in view of the large coal mine 0908 transport of roadway floor drum up serious damage phenomena, through the theoretical analysis of indoor experiment, numerical simulation and industrial test on the site, determine the failure mechanism of roadway ,and based on the optimal scheme, floor drum up integrated prevention control countermeasures are put forward. The results show that the surrounding rock of 0908 transportation roadway is affected by the low strength of engineering rock mass, the joints fractured and high concentration stress by mining ,the overall shows the large deformation failure characteristics of soft rock,which including severe heave, large floor heave and large wall shrinkage. According to the analysis, the surrounding rock of roadway is ⅠABⅡABDⅢABC composite deformation mechanical mechanism, and the integrated control strategy for floor heave prevention is put forward, which transforms the composite into ⅡB stable deformation mechanical mechanism. Field application results show that floor heave failure is effectively controlled, the deformation of floor is less than 97mm, and the maximum deformation of surrounding rock is less than 120mm. The research results provide reference for the research of floor heave failure mechanism and control countermeasures of similar deep buried soft rock roadway.

In order to solve the problem of controlling the stability of gob side entry in thick coal seam, taking Buertai coal mine as the engineering background, the surrounding rock failure mechanism of 42108 auxiliary haulage trough and the integrated control countermeasures of bolting and grouting are systematically studied by means of field investigation, numerical analysis and field industrial test. The results show that: the deformation of the surrounding rock is more obvious due to the influence of low rock strength, superposition of strong mining stress, thick layer of hard roof and groundwater in 42108 auxiliary transportation chute. The top gang deformation and right gang deformation of the roadway during the damage of 42108 auxiliary transport chute are obvious in the numerical simulation results, which are 658mm and 602mm respectively. The top, bottom, left and right gang displacements of the surrounding rock are 149mm, 26mm, 7.7mm and 79mm respectively after adopting the integrated anchor injection control countermeasures, which are reduced by 77.3%, 62.9%, 98.3% and 86.8% respectively. It is verified by field engineering application that the roadway can carry the deformation and pressure caused by the influence of mining under the hollow anchor cable grouting support, and the field application effect is good.

Mining-induced strata separation grouting is an important key technology to reduce surface subsidence, and its effect directly determines the final settlement reduction effect. The layout of grouting boreholes is the key to the final settlement reduction by grouting. In this paper, the complete set of drilling construction technology of subsidence reduction grouting is studied from four aspects, including process principle, process flow, operation points and quality control measures, and a complete set of grouting drilling construction technology is obtained, which is applied to the subsidence reduction engineering practice of railway bridge in Fangezhuang Mine. The results show that the technology increases the injection amount of fly ash slurry by 236 %, and at the same time, through the observation of surface movement, it can be known that the subsidence reduction rate reaches 60.99 % by using this technology. The drilling construction technology has certain guiding significance for the design and construction of related separated grouting subsidence reduction projects.

The side production operation of Xiwan open pit Coal Mine is greatly affected by burnt rock water. In order to reduce the influence of side water gushing on stripping operation and reduce the damage of mine drainage to the ecological environment, the scheme of using clay-cement slurry to construct clay-based flexible curtain water partition wall is proposed to block the passage of burnt rock water and surface water into the pit and realize water-preserving coal mining. The clay stripped from the pit is used as the raw material, and the clay-cement grout ratio obtained through the field test is used as the grouting material for the construction of curtain waterproof wall. After the construction of the curtain wall is completed, the displacement of the mine decreases by 89.82%, the water level inside and outside the curtain wall changes obviously, and the vegetation around the pit can be better restored. compared with the cement-fly ash slurry scheme, the cost of grouting materials is saved by nearly 0.88 million yuan. Engineering practice shows that the clay-based curtain wall has good water resistance, outstanding economic benefit and obvious ecological benefit, and the water conservation mining has been realized. It provides a new method for water gushing treatment and water conservation mining in the side of open pit.

In view of the lack of measured data of failure depth of miningfloor in deep buried and ultra-long working face, the stress, water pressure and strain sensing tests were carried out on the fault part of the second level deep ultra-long working face and the floor of intact coal seam in Chengjiao coal mine by using the field test method. Two measuring holes were arranged on the typical 21105 working face for disturbance and failure monitoring of floor respectively. A strain sensor, stress sensor and water pressure sensor were buried in the vertical depth of floor 10.5 ~ 11.5m in the fault part, and the monitoring points ranged from 65m before mining to 42m after mining. Four strain sensors and one stress sensor were buried in 18.0-32.0 m vertical depth of complete coal seam floor respectively, and the measured data of disturbance failure depth of mining floor were obtained from 55m before mining to 52m after mining. The experimental results show that the depth of mining disturbance is much greater than 10.5m, and the water pressure and additional stress increase first and then decrease gradually, indicating that the surrounding rock is affected by mining, but the influence is very small. In the vicinity of intact coal seam, the increment range of strain induction at measuring point 5 and 4 is 15779με and 12023με, respectively. The strain induction degree of measuring point 3 and 1 is relatively weak, and the normal working state is basically maintained during the whole observation process. The maximum value of additional stress at measuring point 2 is only 14 MPa. The failure depth of the working face floor ranges from 22.0 ~ 27.0m. The test data provide scientific basis for the design of water hazard control scheme for the deep buried and long working face of suburban coal mine.

Against the problem of insufficient research on mining pressure monitoring of top coal caving in super-large mines currently represented by Shendong mining area, this paper takes the top coal caving face of Buertai Coal Mine as the background, and conducts field measurement research on the ground pressure under this condition. The following conclusions are obtained: 1) The roadway deformation monitoring shows that the total subsidence of the tailgate roadway is 100-130 mm, deformation of coal face side is 150 mm, the other side is 100 m, the maximum roof separation is 5 mm, the roadway deformation degree is controllable; 2) The surrounding rock stress results show that the influence range of the advanced bearing pressure is greater than 75m high, and the advanced bolt and cable protection must be strictly implemented; 3) The force monitoring results of the hydraulic support on the working face show that the initial pressure The step distance is 71.3 m, the duration of incoming pressure is 16.9 m, the average step distance of periodic incoming pressure is 14.8 m, and the incoming pressure distance is about 9 m; 4) The microseismic monitoring results show that the microseismic events are mostly concentrated near the nose and tail of the aircraft, the microseismic and large energy events gather near the coal pillar in the lateral goaf. The research can provide reference for the prevention and control of mine pressure in high-yield and high-efficiency top coal caving mines.

In view of the frequent occurrence of low oxygen in the return air corner of Shendong mining area, from the perspective of structural characteristics of overlying strata in goaf of shallow buried depth and close distance coal seam group mining, the 22104 working face of Shangwan Coal Mine was taken as an example, and the PFC discrete element software was used to simulate and study the variation law of rock caving, fracture development and stope stress in the mining process. The results show that under the occurrence condition of shallow buried depth and close distance coal seam group, cracks can develop to the surface, forming through air leakage channel; the mining of lower coal seam can lead to the formation of composite goaf, and at the same time, it has a significant activation effect on the old caving space in the upper part. The development degree of fractures increases, which aggravates the surface air leakage. The mining of the upper coal seam will cause a large pressure relief of the roof of the lower coal seam, which makes the roof of the goaf not easy to collapse and is easy to form a large area of suspended roof. The low oxygen prevention and control system combined with goaf air leakage control, working face pressure regulation and forced roof caving was proposed and established to solve the problems of serious surface air leakage, low oxygen gas emission in composite goaf and sudden collapse of large area suspended roof, respectively, and effectively solve the low oxygen problem in the return air corner of working face.

At present, the automation level of coal mine auxiliary operation in China is not high, and the degree of intelligence of relevant equipment is low. Among them, the installation equipment of underground auxiliary pipelines in coal mines are rarely studied, most mining enterprises still use traditional manual installation, which consumes a lot of labor. For these problems, the study of the control system of multi-axis mechanical arm in coal mines is carried out, including two aspects: (1) Based on embedded Linux operating system, multi-source sensor signal acquisition, analysis and fusion processing, multi-axis hydraulic manipulator and its control system, intelligent algorithm and other technologies, the perception and control system of an automatic installation robot of underground pipelines is designed and developed; (2) Based on the infrared video image and laser radar point cloud data collected by the perception and control system of multi-axis mechanical arm, the pipe support target recognition methods based on image and point cloud data are proposed respectively. In the actual underground coal mine tunnel pipe support scene, the proposed target recognition methods can effectively identify and tag the pipeline and pipe support in the tunnel, which shows the potential of the proposed methods to be applied to the actual coal mine automation auxiliary installation of pipeline.

The real-time video of fully mechanized coal face is the necessary reference information to realize remote visual automatic coal mining. As the video image acquisition equipment, the camera has become the standard configuration of intelligent chemical face. At present, the fixed camera normally used in the working face has limited viewing angle range and large monitoring coverage blind area; Although the pan tilt camera can be rotated to adjust the angle of view, the monitoring pictures cannot be synchronized in a large range, which can not provide real-time and comprehensive video pictures for remote control, and there are certain potential safety hazards. Based on the defects of video monitoring in intelligent chemical working face, this paper analyzes the concerns of camera matching in thin coal seam, medium thick coal seam and large mining height working face, and combs out the relatively comprehensive design requirements. After field angle analysis, main component selection, product architecture planning and circuit safety design, the intrinsically safe multi-objective panoramic camera in fully mechanized mining face is developed, It has a fixed wide-angle monitoring angle of 220 ° horizontally and 90 ° vertically, and the 8million pixel, star level ultra-high definition panoramic picture simultaneously covers the real-time monitoring of the coal wall and the support side environment; The application tests are carried out in the working faces of large mining height, medium thick coal seam and thin coal seam respectively, and the problems existing in the application process are summarized and the follow-up improvement measures are put forward. The application test shows that the developed multi view panoramic camera can realize real-time, full coverage and no dead angle monitoring for the sensitive areas involved in the automatic coal mining process of the working face, ensure the reliability and safety of remote visual coal cutting of the unmanned mining working face, realize "clear" and "complete", and provide the most comprehensive data source for the follow-up "understandable" intelligent identification research, It provides a new video monitoring technical support and product support for the intelligent working face system.

In order to explore the deformation failure characteristics of large mining height stope roof under the effect of dip angle, based on the comprehensive analysis of roof deformation and sliding filling characteristics, this paper studies the roof caving and migration filling law of large-mining-height working face under different dip angles. The results show that due to the influence of the dip angle of the working face, the deformation and failure of the surrounding rock and the filling form show obvious asymmetric characteristics. With the increase of the dip angle of the working face, the length of the gangue support area increases, and the unbalanced constraint effect of the filling gangue on the roof along the dip and strike is enhanced. The regional characteristics of the loading and deformation failure characteristics of the stope roof and the pile-hinge structure formed after the failure are more obvious. The damage degree of the roof in the middle and upper parts is increased, and it is easy to slip and deform and lose stability, forming impact pressure, resulting in a significant increase in the unbalanced loading degree and instability probability of the support in different areas. The stability of the ' support-surrounding rock ' system is greatly reduced, which is easy to induce the disaster of surrounding rock in the working face.

Abstract：At the initial stage of the design of Shenshupan Coal Mine, the panel air return roadway was not designed. During the mining of Panel 31, the main air return roadway was also used as the panel air return roadway, which easily led to the wind speed exceeding the limit. In order to meet the needs of ventilation, ensure the safe production of the coal mine, and solve the hidden danger that the return air in the south wing of Panel 31 exceeds the limit, it is decided to construct a panel auxiliary return air roadway 20m outside the goaf in the north wing of Panel 31. Therefore, on the basis of summarizing the ground pressure monitoring data of 31104 working face in Shenshupan Coal Mine, the reasonable size range of coal pillar for roadway protection is calculated by using coal pillar load estimation and limit equilibrium zone theory; After comprehensive actual measurement analysis and theoretical calculation, taking the geological conditions of coal seams and roadway layout as the background, through numerical simulation of the internal stress and deformation laws of roadway protection coal pillars under the conditions of 10m, 15m, 20m and 25m roadway protection coal pillars, the research results show that: under the influence of mining on one side, 20m roadway protection coal pillars can meet the production needs.

In view of the coal mine production safety background of frequent roof accidents, the principle of force-measuring bolt is analyzed, and a distributed real-time monitoring force-measuring bolt system is constructed, including distributed force-measuring bolt, real-time acquisition substation, intelligent gateway and dynamic intelligent early warning platform. The working conditions such as axial force and bending moment of the bolt can be dynamically and real-time monitored. When the axial force of the bolt exceeds the safety threshold, the system will accurately issue safety warning. The working principle, preparation process and calibration method of distributed force measuring bolt are given. The distributed real-time monitoring force-measuring bolt was successfully applied in the transportation roadway of 21105 working face in Lushun, 1126 ( 1 ), Guqiao Coal Mine, Huainan, and Gaoyang Coal Mine, Fenxi, Shanxi. Based on the monitoring results, the evolution laws of axial force and bending moment of the bolt were analyzed, the response relationship between axial force and periodic weighting of the stope was predicted, and the working condition response law of the bolt during the mining of the roadway was revealed. In the force-measuring section, the ‘ original rock stress zone, mining influence zone, and severe influence zone ’ were divided, which provided data support and guarantee for the bolt support design optimization and roof safety of the roadway.

Rockbolts and cables were prone to corrosion affected by mine water, which usually lead to the degradation of mechanical properties and failure. The basic properties, electrochemical characteristics and corrosion rates of hot-rolled 335, hot-rolled 500, heat-treated 600, heat-treated 700 rockbolts and 1860MPa cables in simulated highly-mineralized mine water were tested and analyzed by chemical composition analysis, microstructure observation and electrochemical tests. The main conclusions were as follows: ①The polarization characteristics of rockbolts and cables tested were active dissolved similarly.②In the simulated corrosive solution, the corrosion rate of heat-treated 600 was the lowest and hot-rolled 500 the highest, with an average corrosion rate of 0.2mm/a. The average corrosion rate of hot-rolled rockbolts was about 1.5 times that of heat-treated ones. The corrosion rate of cable was about one tenth of that of rockbolt.③The pH of mine water had a significant effect on rockbolt corrosion rate, which reached the maximum in pH=2.When pH=5, the corrosion rate decreased to about 20% of that in pH=2. When in pH=5-12, namely weak acid, neutral and alkaline solutions, the corrosion rate decreased slightly in general.④Cl- concentration had certain influence on the corrosion rate of bolt. The corrosion rates of the four rockbolts decreased gradually when Cl- concentration increased from 0.906mmol/L to 90.6mmol/L. When increased to 906mmol/L, the corrosion rate of hot-rolled rockbolt continued to decrease, while that of heat-treated rockbolt began to increase. The corrosion rate of cable increased by 13.35% in 100 times Cl- concentration solution.

There are many layers of burnt rock aquifers with extremely uneven water abundance which is interbedded and overlapped with fissure developed weathered bedrock aquifers in the coal seam roof of the northern Shaanxi mining area. It is of great significance for mine safety to accurately evaluate the water abundance of both and scientifically predict the water inrush hazard of coal seam roof. This paper takes 5-2 coal in Zhangjiamao mine field as an example. The evaluation indicators of water abundance are selected based on the hydraulic characteristics, aquifer thickness and lithologic difference of weathered bedrock and burnt rock of 2-2 coal, 3-1 coal and 4-2 coal. To improve the method of weight determination, comprehensive weighting method based on AHP and the entropy weight were adopted to accurately characterize the spatial water-abundance characteristics of the target aquifers. The calculation method of the guided height based on the correction coefficient is put forward and the thickness data of the guided fractures entering the aquifer are drawn into the partition diagram of the roof cracking stability. By superimposing two kinds of geospatial information, the classification and zoning prediction of roof water inrush risk of 5-2 coal in Zhangjiamao coal mine are realized. The research result provides a new method for prediction of roof water inrush risk under the complex geological conditions of multiple aquifers discontinuous interbedded and an important basis for roof water hazard prevention and control.

The solution to the roof problem cannot be separated from the peep exploration of the roof rock structure. Based on the drilling simulation system with multi-parameter and multi-angle identification of roof structure, this paper conducts drilling simulation tests on different characteristic rocks. The main influencing factors in the process of drilling and rock breaking and the energy loss in the process of drilling were studied and analyzed. The specific work of rock breaking per unit volume was deduced, and the method of fitting with the compressive strength of rock as the identification parameter was proposed. The qualitative relationship between the drilling parameters and the relationship between the specific work of rock breaking per unit volume η and the compressive strength were explored through the simulation test.

Given the complexity of emergency rescue for water hazard incidents in domestic coal mines, the paper analyzes the status quo of manufacture, usage and technology of submersible pump for emergence rescuing purpose, and discusses existing related problems. The trend of emergence rescuing submersible pump in China is then researched and demonstrated, as well as key technologies to be solved and tackled. Study shows that light-weight and mini emergency rescuing submersible pumps applicable to water hazardous environmental conditions, and supporting emergency drainage pipelines with high strength, light weight, fast joint, excellent compatibility and other features, are the inevitable trend in the future. In the meanwhile, that will improve emergency rescuing capacity for coal mine water hazard incidents constantly.

The large amount of latent heat released by unconventional water in the process of icing can be extracted by the phase change heat exchange device as a low temperature heat source for heat pumps to solve the shortage of conventional heat sources (mine drainage and exhaust air; natural gas and electrical energy) in coal mines. In this paper, an industrial experimental study on the coupling of casing phase change condensing heat transfer device and low temperature heat pump system developed for coal mine heating system is carried out, and the research results show that the COP of the system is up to 3.57 in the condensing heat transfer stage, and the heat transfer coefficient decreases from 520 W/m2-K to 285 W/m2-K and the COP decreases from 3.57 to 3.29 when the thickness of icing is between 10 and 30 mm. this study provides improve the benefits of unconventional water resources chemistry and build a model for efficient utilization of unconventional water resources chemistry in mines provides a reference.

In order to reduce the occurrence of ecological geological environment disasters caused by mining surface subsidence effectively, Huangyuchuan coal mine has developed a Tianyan-patrol monitoring system for surface subsidence area with traditional surface movement observation station combined with GNSS, UAV, remote sensing, radar and modern sensor technology. The system designs five core functions according to different research objectives and data acquisition ways. The software architecture adopts the modern design concept of front and rear end isolation to separate the data acquisition end, data service end and client end. The data acquisition end transmits the data to the server through GPRS / 4G / 5G technology for data storage and management. Data storage management and application programs are deployed on the server side to realize data management, analysis, mining subsidence calculation and response to client requests. The client realizes data query, modification, and large screen display through HTTPS request of browser. The client and data server design rest API technology to realize the separation of front and back ends. Taking the three functions of surface movement observation station analysis, geological environment risk zoning and mining subsidence prediction of 11401 working face of Huangyuchuan coal mine as examples, the engineering application demonstration is carried out. The deployment and application effect of the system shows that the system realizes the integration and unification of data acquisition, data management and data use. It provides a basic basis for data analysis and decision-making in the direction of ecological geological environment monitoring to promote the construction of intelligent green mine in Huangyuchuan coal mine. The system research results have popularization and application value in other underground mining areas.

Rock-breaking by high-pressure water jet is a non-linear dynamic problem with many influencing factors. Aiming at the instantaneity of rock-breaking process by jet and the problem of avoiding mesh distortion in finite element method, the rock-breaking process by continuous jet is simulated based on ALE algorithm. Jet and air adopt ALE format and rock adopt J-H-C model. Then the rock-breaking mechanism, rock failure form and rock damage by high-pressure water jet are analyzed. Characteristics of injury. The results show that rock fragmentation is the result of the combined action of impact pressure, water hammer pressure, stress wave and water wedge. Rock fragmentation by jet has periodic cyclicity, and each mode of action has corresponding dominance in different stages of rock fragmentation cycle. The failure mode of rock is time-varying. At different times, the failure mode changes constantly, and the final failure mode is funnel-shaped or deep "V" shaped. Rock damage has stages, which can be divided into non-damage stage, intensive damage stage and failure stage. Rock failure has local characteristics and zoning, which can be divided into damage zone, damage zone and original state zone.

There is a strong trend of sedimentation in low density heavy medium suspension, which may worsen the effect of cyclone separation and enrichment of vitrinite in dense medium cyclone (DMC). In this study, low ash slime, montmorillonite and their mixed composite slime were used as non-magnetic materials to reveal their effects on the cyclone stability and actual separation. The results show that: 1) with the increase of non-magnetic content, the underflow concentration, overflow clarity, concentration efficiency and underflow density difference of the suspension decrease, and the stability increases. And the addition of composite slime has better stability. 2) the concentration efficiency and overflow clarity of suspension with montmorillonite and magnetite powder are higher than those without non-magnetic substance, indicating that the system is more unstable. 3) the target of concentrate with ash content less than 3% and vitrinite content higher than 75% can be obtained by using suspension with magnetic content of 30% and 40%. The lowest possible deviation E value of separation is 0.034g/cm3, but when its content is more than 50%, or the suspension with only low ash slime or montmorillonite cannot meet this requirement. 4) although the addition of too much non-magnetic material can further improve the stability of the suspension, it can also hinder the migration of the selected coal particles in the DMC and make the separation effect worse. therefore, there is an optimal value of non-magnetic content in the suspension.

The industrial analysis and instrumental characterization of coal slime from a coal preparation plant in Ningdong were carried out, and the effects of different flocculants, flocculants and their combination on slime sedimentation were studied. The results show that the ash content of the coal slurry is as high as 47.58%, which contains a certain amount of kaolinite and montmorillonite. There are more oxygen-containing functional groups in the slime, and it has certain hydrophilicity, and the Zeta potential is -32.47 mV. There is strong electrostatic repulsion between the solid particles in the slime water, and the slime water system is stable and not easy to settle. Secondly, in slime water sedimentation test, the effect of PAC is better than PAS and PFS, and the best effect is when the dosage of PAC is 15kg/T. The effect of flocculant CPAM is better than Apam, ACPAM and NPAM. The optimum dosage of CPAM is 150g/t. When PAC and CPAM are used together, when the amount of CPAM is 150g/t and the amount of PAC is 10kg/t, the comprehensive index of slime water is the highest. The settling velocity of coal slurry is 0.65 cm·S-1, the turbidity of supernatant is 44.26 NTU, the floc height is 3.57 cm, and the comprehensive index is 1.26 cm·s-1·NTU-1.

In order to investigate the adaptability of dry pulverized Gasification for Shenhua coal in HT-L gasifier, this paper systematically analyzes and summarizes the quality characteristics and gasification characteristics of the coals used in HT-L gasifier. Taking three Shenhua coals from Yanjiata, Daliuta and Batuta as the research objects, the industrial analysis and ash melting characteristics of these coals are compared with the feed coals for HT-L gasifier. The results show that the bituminous coals are favourable used in HT-L Gasififer via the pressurized gasification technology of pulverized coal. The anthracite coal with high ash melting point can be used in HT-L Gasififer via adding fluxing agent or mixing other coal. The three kinds of Shenhua coals have the characteristics of bituminous coal with high volatile matter, high calorific value, low ash and low sulfur. Base on the industrial analysis, these Shenhua coals meet the coal quality requirements of HT-L Gasififer. However, the adaptability of the Shenhua coals from Daliuta and Batuta for HT-L gasifier need to be improved by mixing with other coal, for the reason that the ash melting points of these Shenhua coals are relatively lower.

The vibration energy generated by the rocker arm of shearer can be converted into electrical energy to power the wireless sensor node through energy collection technology, but the current common piezoelectric power generation device has high natural frequency and low output power. In order to improve the efficiency of vibration energy collection of shearer rocker arm, the typical cantilever piezoelectric power generation device was modeled and analyzed, and the parameters affecting the output voltage and power were found. A multilayer arrangement piezoelectric structure was designed, and the COMSOL software was used for simulation verification. The results show that the natural frequency can be reduced by changing the length and mass of the cantilever beam, and the resonant points in the frequency range below 625Hz are increased to 4, and the output voltage and output power of the piezoelectric power generation device are increased by 65% and 172.4% respectively under the same external conditions.

In order to solve the problem of large volume of L, LCL filters for shearer traction and limited ability to suppress high-frequency harmonics near the switching frequency of rectifier, based on the analysis of the structure and filtering characteristics of L, LCL, LLCL filters, the element volume and loss are added as limiting conditions, and the relationship between inductance ratio, damping resistance and current attenuation coefficient, resonant frequency, damping loss is analyzed, A parameter design scheme of a special LLCL filter for the rectifier side of the traction frequency converter of underground shearer is proposed. By using simulation test and actual test, it is determined that LLCL filter can improve the high-frequency harmonic suppression characteristics, reduce the harmonic distortion rate of feedback current, reduce the harmonic impact on the power grid, and further reduce the filter volume and loss; Compared with the traditional design method, the designed total inductance and loss are lower, and the working cost is saved.

In order to improve the power generation efficiency and protect the gas generator set, it is necessary to separate the liquid water in the gas before the gas enters the generator set. Firstly, this paper analyzes the advantages and disadvantages of different gas-liquid separation mechanisms, and designs a vertical gas-liquid separation device combining gravity and screen filtration. Then, the diameter design of vertical gas-liquid separation device was carried out based on the fact that the gas rising velocity in the gas phase space was equal to 80% of the droplet settling velocity. Then the screen of the gas-liquid separation device was selected. Finally, the height of the device is designed.The gas-liquid separation device is designed according to the working parameters of the DN500mm gas transmission pipeline in Shanxi lanneng power station. The calculation shows that the diameter of the gas-liquid separation device is 1.3m; SP type wire mesh demister with nominal diameter of 1.1m shall be selected for wire mesh; The total height of the gas-liquid separation unit is 2.92m.