Research On Rapid Testing Technology For Rolled Defects In Power Plant Boiler Heating Tubes

Safe,economic and reliable operation of power plants directly influences the national economy and people's livelihood.Among many equipment parts in power plant,boiler's heating tube is an important part of,it usually works in high temperature,high pressure,corrosion,fatigue,and under complex stress conditions,its product quality,is very important to continuous reliable operation of generating set.In recent years,the accident of the power plant boiler heating tube leakage occurs due to defects of rolled tube boiler frequently,it has had a huge impact on industrial production and people's life.According to the boiler heating tubes rolled defects seriously endanger the safe operation of generating units,and the existing method is difficult to detect the defects quickly and effectively,a method called direct contact double crystal probes lateral-wave testing is designed.The main research contents include the design of the lateral-wave probes,the design of the special reference block,the construction of the the experimental platform of automatic testing system.The lateral-wave probes use bimorph wedge fixed at specific angle,are assumed to transmit and receive lateral-wave,sound insulation layer is arranged between the piezoelectric crystals to prevent mutual interference.Two kinds of reference blocks are designed,DB-? block is used to test and determine the final feasibility of the testing method and adjust the sensitivity of the testing,DB-? block is used to test the incident point and refraction angle of the probes after processed concave cambered surface.An experimental platform with probes fixed on a mechanical transmission device for oscillating feeding and a 4 channel ultrasonic test instrument is set up,and it may install the probes of different reflection times according to the needs.The experiment proved that direct contact double crystal probes lateral-wave testing method of boiler heating rolled defects is accurate,fast and efficient,for the prevention of boiler tube explosion accident,reduce the times of unscheduled outage,improve the production efficiency can have a positive effect,has better economic benefits.