The Research On Eddy Detection In Steam Generator U-tube Of Nuclear Power Plant By Numerical Caculation

Eddy-current testing(ECT) is one of non-destructing testing methods based on the electromagnetic theory. It is an experiment method that uses the electric and magnetic properties presented by the material in the electromagnetic field to estimate the inner constitution, function, and the geometry shape of the test specimen. ECT is far-ranging used for detecting in steam generator U-tube of nuclear power plant by the virtue of fast velocity、high sensitivity and non-touch with electricity, etc. But it is the difficult problem to distinguish the tube- disfigurement by the signal of ECT in project.The traditional research of ECT technology has been based on simulating disfigurement with testing specimen, but owing to it’s cost expensive and could not simulate discontiguous disfigurement in some conditions, so could not satisfied the demands for the project of nuclear power, has been maken against the continual progress of ECT. The numerical simulation could explore the relations between signal and disfigurement of ECT’s in theory, which could become an important instrument in research of ECT. It is redounding to complement the shortage of traditional’s experiment, exploiting the instrument and reinforcing the ability exactly to estimate disfigurement in tube.This paper is adopting numerical calculation based on the finite element as the analytical instrument, regarding the Steam Generator U-tube of Nuclear Power Plant and test-coil as the model of symmetrical axis electromagnetic field, mainly bringing to bear finite element method and analytical results, holding the relativity between results of calculation and experiment’s, validating that interrelated theory and calculation are accurately. And then obtained the data by carrying idiographic experiment, in the next compared the disfigurement data by simulative calculation and experiment’s data, educed the quantitative reliability outcome, and ulteriorly discussed the capability effects of eddy current testing by scan quomodo of probe coil which has definite reference value in nuclear power field.