| In the process of production and transportation of raw coal underground,one of the key factors affecting the whole process is the balance between production and transportation of coal.With the development of science and technology,modern underground mining transportation equipments are more and more complex.The reliability of transportation equipments has a direct impact on the balance between production and transportation of coal.The more complex the transportation equipments are,the higher the requirement for the reliability of the transportation equipment is.If the reliability of the equipments fails to meet the requirement,the transportation system will fail more likely,and the loss will be greater too.This paper analyzes and improves the reliability of the underground transportation system for the Liangshuijing mine well.The reliability of the transportation system where the raw coal is transported from the mining face to the bottom coal bunker is studied.In view of the low stable-state effectiveness of Liangshuijing well transportation system,the reasons for the current situation is studied.Then,the main transportation system is modeled,and the general method of Markov process is used to find out the reliability indexes of each part of the system.Fault tree,Pareto Diagram and statistics are used to analyze and improve the weakness of the system and equipment.The improvement measures are evaluated from economy and security perspective.The results and conclusions are shown as follow:(1)It is found that the stable-state effectiveness of the eastern sector was 0.775,while that of the western sector was only 0.628.After a buffer coal bunker was added in the western sector to optimize the structure of the transportation system,the stable-state effectiveness of the western sector will be improved to 0.658.The construction cost of coal bunker is about 600,000 yuan,and the planned service life is 5 years.After completion,the annual output of the raw coal will increase by 48000 tons,or 1.92 million yuan.Therefore,the construction of coal bunker conforms to the principle of economy.Furthermore,the construction of coal bunker meets the safety requirements.(2)The belt conveyors are the weak equipments in the system.According to the fault tree diagnosis results,the main cause of the conveyors fault is the drums fault caused by the belt overheating.The installation of temperature sensor devices will reduce the probability of drums failure due to overheating and reduce the cost for drums maintenance.The belt fault will be decreased and the economy of the system will be increased due to the reduce of the idle time,after the installion of the belt protection device.The risk of fire accidents caused by overheating will also be effectively reduced by the improvement of the belt.After the improvement,the comprehensive reliability of the system is increased from 0.9163 to 0.923.(3)The reliability of the system can be further improved by strengthening the equipment maintenance and adopting the equipment condition maintenance system.This paper contents 38 figures,21 tables,52 refreences. |
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