Research On Reliability Of Safety Protection System Of Lifting Mechanism Of Nuclear Environment Crane Based On SIL

In recent years,with the continuous improvement of science and technology,the reliability requirement of crane in nuclear environment is getting higher and higher.However,at present,there is no in-depth study on the impact of potential failure modes,failure mechanisms and reliability indicators in the design process on crane in nuclear environment,ignoring the potential risks of crane in nuclear environment,which limits the development of nuclear crane to a certain extent.In this paper,the safety protection system of crane in nuclear environment is taken as the research object.According to the reliability principle and safety integrity level principle,the reliability analysis and research of the safety protection system of hoisting mechanism are carried out.Firstly,the safety protection principle of crane in nuclear environment is described in detail.Secondly,through the analysis of reliability theory and safety integrity level theory,the quantitative relationship between system reliability and system safety integrity level is established.Then,The chapter that follows is concerned with establishing the reliability analysis model of safety protection system for hoisting mechanism of crane in nuclear environment.Based on this model,the reliability of safety system and brake system are studied respectively,and the reliability models of different structures are established,so that the reliability calculation formulas are deduced.Finally,according to the model established above,the relationship between failure probability and safety integrity level of safety system in different redundant structures corresponding with the relationship between failure rate and safety integrity level of brake system under different working conditions of operators and different safety factors of brakes can be calculated.From this,the relationship between the system and safety integrity level under different models and parameters is obtained,which effectively promotes the technical progress of the safety protection system of nuclear crane in design,manufacture,installation,use and supervision,and also has important reference value for the development of crane in nuclear environment.