| Mine ventilation system is a complex system composed of many variables with uniquesignificance for mine safety. With the increasing depth and the expanding scale of coal mining,ventilation systems would become more complex, and may lead the system reliability reduced.So research on reliability of ventilation system has its practical significance and theoreticalvalue. By analyzing the reliability of mine ventilation system, possible failures and potentialcauses of accidents during operation process can be found timely, which are the scientificbasis for designing and supervising of the mine ventilation system, thus more comprehensiveand reasonable indexes can be composed to evaluate the reliability of part or the wholesystem, and substantially improve the safe operation of mine ventilation systems.Based on its special characteristics of mine ventilation system as shown in the paper, thesystem is regarded as a repairable system composed of subsystems as ventilation net and mainventilation fan. Proper indexes are chosen for reasonable reliability analysis, and twoIndicators of availability and reliability are adopted. Firstly, analysis of the reliability ofairways is performed. When the concept of airway reliability is used,not only the air quantityin the airway is considered,but also the concentration of gas,air temperature andconcentration of other harmful substances in the airflow is considered as constraint criteria.That is to say, the air quantity and the air quality are both required in a defined range at thesame time. The availability of airways can use the two indicators which are average normalventilation time and average time to failure of ventilation to measure. Then established thereliability calculation model of ventilation network, according to the network topologyrelation, put forward probability importance and critical importance of the availability ofairways to analyze influence of the branch airways on the availability of the whole ventilationnetwork. Ventilation buildings are classed as obstructing building, winded building andadjusting building, and evaluated reliability of building from these three aspects. As for therepairable property of ventilation fan system, the reliability analyzing model is set up by using the Markov Process theory, then deduced availability and reliability and average first failuretime of main ventilation fan system, and analyzed failure rate of main ventilation fan.Combination of the above reliability analyzing methods, analyzed the influence factorsof mine ventilation system reliability, and combined with its own characteristics, put thereliability and availability as evaluation index of reliability, quoted examples analyzing frommine ventilation network reliability and mine main ventilation fan reliability. |
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