Reliability evaluation of mine ventilation systems based on multi-state system theory

Mine ventilation system plays an essential role in underground workings. To improve the reliability of mine ventilation systems, main fans often include cold-standby units. It makes main fans have several possible states with distinct performance rates (levels). When multi-state main fan components are operating in combination, the entire mine ventilation system performs with various levels in air-flow rate. In this paper, we apply multi-state system (MSS) theory and methods to the reliability evaluation of mine ventilation systems. The states of the main fan component with a cold-standby unit are investigated and the corresponding steady-state probabilities are calculated by using Markov process. Then, the Universal Generating Function (UGF) technique is used to determine the availability of the entire mine ventilation system. An illustrative example is subsequently employed to demonstrate how to apply the proposed approach.