Abstract: By using the Markov model, the reliability model of deaerator water level protection system was established. The influences of system structure, the diagnosis coverage rate, the common factors and others on the reliability of deaerator water level protection system were analyzed. The simulation data show that to adopt multiple redundant system structure, to increase the system diagnosis coverage rate and to reduce the influence of the system common factors can increase the MTTF of whole system and decrease the system failure rate.

Key words: reliability, Markov model, diagnosis coverage rate, common factors, mean time to failure (MTTF), failure rate, deaerator water level