PROBE AND SYSTEM FOR NONDESTRUCTIVE INSPECTION OF HEAT TRANSFER TUBE OF MOISTURE SEPARATOR AND REHEATER

摘要

The present invention relates to a probe and a system for nondestructive inspection of a heat transfer tube of a moisture separator and reheater of a ferromagnetic material having a curved tube unit and a heat transfer fin. An objective of the present invention is to distinguish the position and shape of a defect by simultaneously measuring a leakage flux of a defect in a circumferential direction and an eddy current of a defect in an axial direction. According to an embodiment of the present invention, the probe for nondestructive inspection of a heat transfer tube of a moisture separator and reheater comprises: a housing having an outer diameter smaller than the inner diameter of a heat transfer tube to be inspected; a magnet inserted into the housing; a differential magnetic sensor which encloses a portion of an outer wall of the housing corresponding to the position of the inserted magnet, and is arranged to be circumferentially parallel with an inner wall of the heat transfer tube when inserted into the heat transfer tube; and an excitation coil enclosing the differential magnetic sensor.;COPYRIGHT KIPO 2020