Research On Invalidation Diagnosis And Condition Inspection Of Heat-pipe In Power Station Boiler

With the increasing capacity of boilers, the unit structure has been more and more complex. Heat-pipes of the power station boiler are more likely to survive failures such as leaking and bursting, which can cause the unscheduled shutdown of the unit and lead to unnecessary losses to power station. To discover and eliminate the potential safety dangers in time, minimize the dangers of boilers and ensure the safe and stable operation of power station boilers, the regular inspection and failure diagnosis for the failure heat-pipes were made.Taking the power station boilers in Tangshan as examples, the failure cases of the four tubes in different furnace types were diagnosed. The state inspection system of boiler heat-pipes in the power station was established. First, through analyzing the conventional test methods in power station boilers the inspection strategies of the key parts of the boilers were optimized. While, through analyzing the main failure forms of the four tubes, the testing methods of different failure mechanisms and failure types were proposed. Secondly, upon the optimization methods failures of superheater of CFB boilers and gas boilers were diagnosed. The results showed that the superheater burst because the long-term overheating produced high temperature creep, which caused the aging metamorphism of detonation tubes. Through the diagnosis on the failure water wall tube of pulverized coal furnaces it was found that under the flames and smoke erosion the water wall has been seriously thinned. Thus, the water wall tube burst because of uneven thermal stress. Finally, through the contrastive analysis of regular and state inspections, upon the real-time monitoring of the boilers the status inspection methods was scientific and reasonable. The state inspection system of the heat-pipes in the power station was established and the relationship between the state inspection and maintenance was coordinated.Studies showed that aiming at different types of furnaces and failure representations of heat-pipes the proper inspection methods were selected, which can quickly and accurately diagnose the failure reasons of heat-pipes and ensure the safe and reliable operation of power station boilers. The research results can enrich the knowledge system of tube failure diagnosis in the power station and provide a theoretical basis and technical support for the implementation of the state inspection methods.