Reliability Analysis Of Boiler Heating Surface Based On Fault Tree And Fuzzy Theory

As a kind of important equipment in civil lives and industry,boilers provide steam and hot water through the method of energy transformation and working fluid state change.In the steam-electric power plant,the reliability of the boilers can directly affects the security of the power plant.The economical and safe operation may be destroyed as leakage occurs on the boiler heat-absorb surfaces,which accounts for almost more than 50% rotating machinery failures.So it is important to analyze the boiler heat-absorb surface failure mechanism and find out the main events lead to those failures.Firstly,this thesis summarized the boiler heat-absorb surface failure mechanism,and the basic events lead to those failures were figured out.Next,the fault tree was built based on the theoretical analysis and the fault tree analysis method.With the boiler heat-absorb surface system studied,the minimal cut set figured out as well as the fault pattern lead to the system failure presented,the main factors influencing the system reliability was brought up.Finally,the robustness of the boiler heat-absorb surfaces and the importance rank of the basis events were sort out after a series of works had been done.These works include investigations with the experts,the transformation of the words to generalized fuzzy numbers and quantitative analysis of the fault tree based on the fuzzy calculator algorithm.The fault tree presented in this paper can help the boiler maintenance personnel sort out the causes to the failures.Thus it can save the time and get the work efficiency promoted.Based on the fault tree,the boiler can be operated safe and sound.