Modeling And Simulation Analysis On The Automatic Tensioning System For Heavy Scraper Conveyor

With the rapid development of coal industry and fully mechanized mining technology,coal mining machinery is toward large-scale,heavy-duty and intelligent direction.As the only transport equipment in the fully mechanized mining face,the safe and stable operation of scraper conveyor is very important.However,during the operation of scraper conveyor,the chain will be loosened due to chain wear and deformation,and the length of chain will also change with the change of its load.When the chain's elongation is too long and does not tense in time,scraper conveyor is very prone to chain stacking and chain jumping accidents.So,all scraper conveyors in actual use need to pre-tension their chains,and the value of tension force is very important to improve the stability of scraper conveyor.Too small tension force cannot achieve the effect of tension.Too large tension force not only increases the wear of scraper chain and its related parts,but also causes greater power loss.The load of heavy scraper conveyor varies greatly.When the load changes greatly,the danger will occur,and the tension effect cannot be achieved only by pre-tensioning.Therefore,the automatic tension of heavy scraper conveyor has great significance to stable operation for scraper conveyor.Fristly,the paper analyses the load of scraper conveyor and the tension of scraper chain by means of conventional design.It is found that a certain mathematical relationship between the tension of chain and the driving force of tail motor for heavy scraper conveyor with drive of head motor and tail motor.Therefore,an automatic tension scheme with variable tension based on the driving force of tail motor is proposed.Then the chain drive system of heavy scraper conveyor is modeled and analyzed by AMESim software.The advantages and disadvantages of conventional tension mode with the tension of constant displacement,tension mode with constant tension and variable tension based on tail driving force are analyzed.The results show that the variable tension based on tail driving can not only realize the self-tension of chain drive system for heavy scraper conveyor,but also realize that the minimum tension of chain is obviously smaller than the constant tension mode,which also proves that the scheme is good.Secondly,the automatic tensioning hydraulic system of the large scraper conveyor is studied.Through the analysis of the program,the key components of the hydraulic system were determined.On this basis,the main components of the hydraulic system were established using the HCD library in the AMESIM software.The key components and systems were then analyzed.The analysis results show that the model can better reflect the dynamic characteristics of the system and meet the tension control requirements of the system.Finally,the fuzzy-PID controller of the system is established by MATLAB/Simulink software,and the co-simulation of the system is established by means of the interface between MATLAB/Simulink and AMESim software.The chain drive system and hydraulic tensioning system are combined with the fuzzy-PID controller.The simulation results show that this control can achieve the tension of the chain of heavy scraper conveyor,and its tensioning effect is better.Taking SGZ1400/5400 heavy scraper conveyor as an example,this paper puts forward an automatic tensioning scheme,and carries out dynamic characteristics analysis and optimal control of the tensioning scheme.The research work of this paper can effectively solve the chain jamming and chain dropping accidents in fully mechanized mining face.It has great significance to improve the mining efficiency of fully mechanized mining face,prolong the maintenance cycle and service life of scraper conveyor,and reduce the maintenance cost of equipment.