Abstract:The development of comprehensive energy in mining areas can improve energy security,reduce environmental impact,promote economic development,enhance energy efficiency and power supply reliability.Therefore,reasonable control of energy in mining areas is crucial.A smart energy management platform based on multi-protocol and microservice architecture has been designed to address the significant energy loss in mining areas and the complex personnel management of energy equipment under traditional operating modes.It has achieved real-time collection and monitoring of data from various energy devices,effectively processing millions of concurrent connections,and ensuring the consistency and reliability of platform data.The design of this platform can improve high concurrency and low latency of data,providing a very valuable platform for the management of comprehensive energy in mining areas.The platform can be applied to many fields such as smart mines and smart cities,and has certain social promotion value.

Abstract:To explore the influence of inlet and outlet pipes on the explosion pressure measurement of flameproof enclosures in a test tank,two different structures of flameproof enclosures were selected as test samples for methane explosion pressure measurement tests.The results showed that the inlet and outlet pipes have a significant impact on the explosion pressure measurement of flameproof enclosures,which is related to the volume,internal structure,position of inlet and outlet ports,and position of pressure measurement points of the flameproof enclosure.The presence of inlet and outlet pipes reduces the maximum explosion pressure and maximum pressure rise rate measured in the test.For flameproof enclosures with small-section connecting structures,the presence of inlet and outlet pipes can accelerate and enhance their pressure overlap.During the explosion pressure measurement of flameproof enclosures,the stop valves of the inlet and outlet pipes should be placed as close as possible to the test sample to avoid the"explosion venting"and"enhanced turbulence"effects of the inlet and outlet pipes.There are many factors affecting the explosion pressure measurement of flameproof equipment,making it necessary to conduct a rational analysis of the test configuration and explosion pressure curve.

Abstract:The low coal loading rate of the coal winning machine drum in thin coal seams is a significant obstacle to the efficient exploitation of thin coal seam resources.Auxiliary coal loading with an arc-shaped coal baffle is an effective measure to address the low coal loading rate of the coal winning machine drum in thin coal seams.Based on discrete element simulation,a numerical model of coal baffle-assisted drum coal loading was constructed to explore the influence of baffle offset distance on the coal loading rate under different coal loading modes of the drum.The research results showed that there was a monotonic negative correlation between baffle offset distance and coal loading rate.Using a smaller offset distance can effectively improve the drum coal loading rate.However,an excessively small baffle offset distance leads to a significant increase in drum conveying torque,which is prone to induce issues such as drum locked-rotor,recycled coal,and excessive crushing.The optimal offset distance range is between 150 and 225 mm.This conclusion has certain reference significance for improving the coal loading performance of the coal winning machine drum in thin coal seams and provides some guidance for the optimal design of coal baffle parameters.

Abstract:It is of great significance to analyze the influence of excavation arm structural parameters on the working area in coal mine tunnel excavation.A standard DH method was used to establish the forward kinematics model of the excavation arm,and an improved Monte Carlo method based on Beta distribution was proposed to generate the workspace and working face.This method uses only 20 000 spatial points and achieves higher boundary accuracy than the traditional Monte Carlo method with 100 000 spatial points.Based on the layer cutting method,the boundary space points of the working face were extracted,and the working area was calculated to be 78.86 square meters.By analyzing the influence of the structural parameters of the excavation arm on the working area,it was found that the length of the high-frequency crushing equipment,the amplitude of the crushing bucket teeth,the swing angle of the rotary table,and the pitch angle of the support arm had a significant impact on the working area.By optimizing these parameters,the activity range can be effectively adjusted.

Abstract:To address the issue of chain wheel failure in coal mine scraper conveyors,the SGB420/40T scraper conveyor chain wheel was taken as the research object.Through theoretical analysis,3D modeling,and finite element simulation,the meshing force of the chain wheel and chain was analyzed.The results showed that there was a stress concentration problem at the chain wheel chain pocket position,with a maximum stress value of 245 MPa,exceeding the material yield strength,indicating that this position was prone to fatigue damage.Based on this,the structure of the chain wheel chain pocket was optimized.Through orthogonal experiment comparison,the optimal optimization scheme was determined.After optimization,the maximum stress of the chain wheel was 210.4 MPa,a decrease of 15％.Verification through engineering practice showed that after optimization,the downtime for fault maintenance during actual use was reduced to 60％of the original,and the equipment operated stably,achieving the expected application effect.

Abstract:Addressing the issue of slippage during the secondary lifting of a heavy load in an open-type pump-controlled volume speed regulation winch hydraulic system,an AMESim software was utilized to construct a simulation model of the winch's mechanical-hydraulic-control system.This model replicated the speed and pressure variation curves during the secondary lifting and slippage of the winch's load.The analysis revealed that the problem stemmed from a mismatch between the activation of the hydraulic brake and the system pressure buildup time.The simulation results indicated that under heavy load conditions,either reducing the opening of the one-way throttle valve at the brake or increasing the initial starting control current of the variable displacement pump could effectively address this issue.

Abstract:Addressing the issue of poor flexibility in adjusting the pressure boosting and unloading frequency of existing emulsion unloading valve test benches,a test system for emulsion unloading valves based on capacitive pressure gradient control principles has been designed.This system combines a digital pilot speed control valve with an accumulator to control the pressure change gradient at the working port of the unloading valve,achieving control over the pressure boosting and unloading frequency of the tested unloading valve.The testing process meets the testing requirements of the coal industry and is conducive to improving the testing efficiency of emulsion unloading valves.

Abstract:With the deepening development of coal mining,the operational stability of shaft boring machines is crucial for operations.Faced with the leading edge of advanced European and American countries in the field of intelligent shaft boring machines,the inefficiency and high risk issues of traditional manual monitoring and maintenance modes in China urgently need to be addressed.This study has constructed a remote monitoring and operation and maintenance management system for shaft boring machines,adopting a hierarchical distributed architecture that encompasses a perception layer,transmission layer,data processing layer,and user management layer.In terms of hardware,sensors such as temperature,pressure,and vibration were reasonably selected and deployed,and data acquisition and transmission were carried out through a combination of wired and wireless methods,while high-performance and scalable servers were selected.At the software level,using Windows Server as the operating system and MySQL as the database management system,the developed monitoring and operation and maintenance software includes functional modules such as data acquisition,processing,monitoring display,fault diagnosis,and maintenance plan management.This system achieves real-time and accurate monitoring,fault warning,and efficient operation and maintenance management for shaft boring machines.It is expected to assist China's coal mining industry in its intelligent transformation,enhance the operational reliability and production efficiency of shaft boring machines,and reduce the incidence of safety accidents.

Abstract:To achieve precise detection and continuous monitoring of longitudinal tears in mine belt conveyor belts,a machine vision-based monitoring method was proposed.An industrial camera was selected as the image acquisition device to design the exposure time for image acquisition of the conveyor belt based on machine vision.Image preprocessing was achieved through noise removal,contrast enhancement,and feature extraction.Based on the processing results,longitudinal tear damage localization and tracking monitoring of the mine belt conveyor belt were carried out.Experimental results showed that the designed method excelled in longitudinal tear detection of the conveyor belt,with a detection accuracy of over 90％,an average absolute error of only 0.05 mm,and a maximum deviation of no more than 0.10 mm.The designed method can detect the location of longitudinal tears in the conveyor belt and based on precise measurement of the tear length,achieve continuous monitoring of longitudinal tears in the conveyor belt.

Abstract:The neutral-point clamped three-level inverter was widely used in fields such as motor control and renewable energy generation.However,it faces issues of neutral-point potential imbalance and high common-mode voltage.To address these two problems,a novel VSVPWM strategy was proposed.Based on the low common-mode voltage switching state switching criterion was proposed,the novel VSVPWM strategy defines new virtual small vectors and virtual medium vectors.This modulation strategy can effectively achieve neutral-point potential balance and common-mode voltage suppression.Furthermore,it overcomes the problems of simultaneous action of two-phase bridge arms in each switching cycle and switching state transitions during region switching in the traditional RCMV_VSVPWM strategy,improving the quality of output electrical energy and enhancing system reliability.Experimental results verify the effectiveness and superiority of the strategy proposed in this paper.

Abstract:With the widespread application of power electronic equipment in various fields of industrial production,the issue of harmonic pollution in power grids has become increasingly severe.Hybrid Active Power Filter(HAPF),as an effective harmonic suppression method,has garnered widespread attention.However,traditional harmonic current detection algorithms were constrained by the performance of low-pass filters(LPFs),leading to a contradiction between harmonic detection accuracy and response speed in the system,often limiting the filtering effect.Therefore,an HAPF control strategy based on an LMS adaptive filter was adopted to address the issue of unable to balance dynamic and static performance.Finally,a system with an input voltage of 220 V,a rated frequency of 50 Hz,and a harmonic source of a three-phase rectifier with variable load was designed,and the correctness of this scheme was verified using Matlab/Simulink.The research results showed that the HAPF controller based on the LMS adaptive filter had good filtering effects,strong accuracy and real-time performance,and could significantly improve the system's control performance and anti-interference capability,with broad application prospects.

Abstract:In view of the problems of physical exploration construction on coal mining faces being constrained by communication,such as widespread organizational chaos,low efficiency,and unsatisfactory physical data collection,various communication systems have been analyzed to achieve efficient communication.Among them,infrastructure-free cluster communication and wireless ad hoc networks are more suitable for regional and temporary needs in physical exploration construction on coal mining faces facing different communication infrastructures.Furthermore,a comparison between cluster communication and wireless ad hoc networks was conducted in terms of portability,installation layout,voice communication,and reliability.Wireless ad hoc networks have obvious advantages in portability,installation layout,and reliability,while cluster communication is better in voice communication.Both cluster communication and wireless ad hoc networks can meet the communication needs of physical exploration construction on coal mining faces.Wireless ad hoc networks have obvious advantages in portability,installation layout,and reliability,and are considered more suitable for physical exploration construction on underground coal mining faces.

Abstract:A design scheme for a coal mine gas inspection system based on a multifunctional LED display screen was proposed to address the problem of missed and false detections in traditional manual gas inspection processes.The system uses a multifunctional LED display screen to replace handwritten gas inspection boards underground,supporting two modes of automatic monitoring and manual inspection.The multifunctional LED display screen can be matched with various types of sensors to achieve automatic monitoring.Gas inspection workers can achieve manual inspection through handheld terminal apps,intelligent portable devices,NFC positioning cards and other devices.A B/S architecture gas inspection management platform software has been developed,which can realize the full process management and information publishing functions of inspection.This system can improve the efficiency of gas inspection in coal mines and enhance the intelligence level of coal mines.

Abstract:Amidst the wave of intelligent transformation in the coal industry,the role of Mining Data Transfer Protocol(MDTP)has become prominent,providing support for the intelligent transformation of comprehensive mining.Focusing on the MDTP data transmission protocol,the actual effectiveness and redundancy situation in different scenarios were analyzed based on the current application status,and a fully mechanized dynamic construction model(FMDCM)was proposed for comprehensive mining based on the MDTP data transmission protocol.This construction model covers data front-end processing module,model framework building module,and model real-time update and maintenance module,aiming to achieve a model construction method that adapts to different devices and application scenarios,helping industry technological innovation breakthroughs and achieving high-quality development.The application results indicated that compared to static model creation,this construction technique is effective in promoting the advantages of device model construction.

Abstract:In the process of coal mine transportation with conveyor belts,there are often challenges such as production line stagnation,equipment damage,and material waste caused by material blockage at the feeding port.Traditional manual inspection methods have defects such as delayed response,high missed detection rate,and dependence on manpower,which affect the accuracy of material flow volume detection.A machine vision based adaptive detection method for conveyor belt material flow was proposed based on the above problems.By integrating laser line scanning and high-resolution camera equipment,real-time image data of the discharge port was collected,and an image enhancement algorithm based on wavelet transform was used to optimize the image quality under complex lighting conditions.Combining optical flow analysis technology to dynamically capture material motion trajectories,and utilizing consistency analysis of material flow area and direction to achieve material blockage warning.Finally,a dynamic coal volume measurement model was established.The experimental results showed that this method could accurately detect the volume of coal flow,with an average relative error of 1.613％,which meets the actual operational error requirements.In addition,the constructed artificial intelligence platform can trigger real-time blockage alarms,effectively improving monitoring response speed and accuracy.

Abstract:In order to solve the problems of high labor intensity,limited equipment selection range,low integration of execution tools,and low degree of automation in the construction of low and deformed roadway surrounding rock cleaning in coal mines,requirements for the selection of roadway cleaning construction technology and models were proposed.A roadway cleaning robot for coal mines was designed,with a focus on key technologies such as robotic arm,tracked vehicle body,tool box,hydraulic system,and electrical control system.The functional characteristics of each component of the cleaning robot were analyzed.A type test was conducted in the workshop,with a cleaning width of 4.2 m,a crushing height of 5.2 m,a crushing depth of 0.5 m,a climbing ability of 15°,and a remote control distance greater than 25 m.The test showed that all indicators met the design requirements,fully demonstrating the rationality and reliability of the structure,hydraulic system,and electrical control system design of the tunnel cleaning robot.The development of the cleaning robot provides equipment guarantee for the construction of low and deformed tunnel surrounding rock cleaning in coal mines,and provides research ideas for similar product design.

Abstract:To address the explosion prevention issues of metro shield and belt conveyors in non-coal gas tunnel construction in Europe,an economical and reliable metro shield method explosion-proof solution was proposed.We have studied the EU ATEX standard and the Italian NIR44 explosion-proof standard,and carried out corresponding explosion-proof designs according to different explosion-proof areas.The design of explosion-proof positive pressure cabinets,belt conveyors,and conveyor protective covers was completed.The method of real-time dynamic adjustment of the explosion-proof area during excavation was adopted,and the positive pressure explosion-proof cabinet was modified and optimized,making the entire explosion-proof system safe,reliable,and cost-effective.The explosion-proof system has been successfully applied to non-coal gas tunnel projects in Italy.

Abstract:Due to the large amount of dust,high humidity,and multiple equipment involved in shield tunneling construction in coal mines,the optical path was obstructed,which affects the measurement accuracy and reliability of the total station guidance.The inertial navigation system is relatively less affected by the environment and can continuously provide the attitude angle of the equipment.Combined with the excavation stroke,it can calculate the spatial coordinates and deviation values of the equipment in real time.However,over time,its own drift leads to a large cumulative error.A method for autonomous positioning and orientation of shield tunneling system based on the combination of inertial navigation and total station was proposed based on the above issues.By analyzing the principle and characteristics of the combination of inertial navigation and total station positioning and guidance,a combined positioning and orientation model was established.Combined with the advancing mileage during the excavation process,the position parameters measured by the total station and the pose measured by the inertial navigation were used to calculate the pose coordinates of the inertial navigation for real-time substitution,and the fusion information of the autonomous positioning and orientation of the shield machine was obtained.

Abstract:Due to the particularity of its application site,there is currently no complete industry standard in the mining full-section excavation equipment industry to guide technology and construction.In order to achieve fast,efficient,safe and high-quality construction,detailed safety management was required for the construction of full-section excavation equipment.By introducing the safety technical requirements and usage requirements of full-section excavation equipment,risk management content such as risk source identification,assessment,and control methods were derived.Finally,construction safety management measures are clarified to provide reference for safe construction management of full section excavation.

Abstract:The starting requirements for TBM excavation construction in coal mines are extremely important.Due to the heavy weight of the TBM host,it is easy to cause bulging and damage to the bottom plate in unstable surrounding rock,which can cause the TBM host to rise or sink,thereby affecting the control of the host's starting direction.By using the method of pouring concrete on the bottom plate and spraying concrete on both sides for reinforcement,the influence of surrounding rock deformation caused by ground pressure was reduced,thereby improving the accuracy of TBM starting excavation direction control and equipment stability.The early excavation always maintains an upward posture,avoiding the occurrence of TBM host"head falling"phenomenon.Based on the geological conditions of the TBM excavation working face in the high extraction tunnel starting chamber of a certain mine,a corresponding plan for bottom plate reinforcement was provided and successfully implemented.