Reliability Analysis For Mechanisms Of Nuclear Polar Crane

The nuclear polar crane is the main equipment for hoisting heavy parts of nuclear power station.In order to ensure the safe operation of nuclear power station,the nuclear polar crane must have the characteristics of high reliability.Therefore,it is very necessary to analyze the reliability of the nuclear polar crane.The reliability of the various mechanisms of the nuclear polar crane is analyzed in this paper.Firstly,the fault tree of travel mechanism,the hoist traverse mechanism,the main lifting mechanism and auxiliary lifting mechanism are established.Considering that the traditional method of building fault tree from top to bottom is difficult to cover all faults,the accurate reliability cannot be analyzed to obtain.So a combination method of forward structure partition and reverse reliability analysis is used to create a more comprehensive fault tree.Secondly,taking the complexity of the types of faults in the nuclear polar crane and the difficulty of reliability calculation into consideration,based on the fuzzy reliability theory,fuzzy mathematics and logic gate formulas,the reliability of the nuclear polar crane is calculated.Thirdly,the fault tree is transformed into a Bayesian network,and the posterior probability of each event is obtained by the Bayesian reverse reasoning algorithm.Due to the different degree of influence caused by each fault,a comparison matrix is established to give weight to each event,and calculate the weighted posterior probability of each event,so as to identify accurately the weak parts of the system and provide maintenance strategies to improve the reliability of nuclear polar crane.Finally,in order to facilitate the analysis and calculation of reliability,the reliability analysis software based on the Visual Basic programming language is established,which could eliminate the cumbersome process of building fault tree,calculating and analysis and provide a convenient and efficient method for the reliability analysis of nuclear polar crane.It is of significant importance to improve the reliability of the nuclear polar crane and crane maintenance in this study.