核电机组高低压加热器U形传热管涡流检测法对比

Comparison on Eddy Current Testing Methods for U-shaped Heat Transfer Tubes of High and Low Pressure Heaters in Nuclear Power Units

核电机组不同类型加热器U形传热管通常采用不同的涡流检测法,从检测原理、方案实施、缺陷分析等方面将常规涡流检测与远场涡流检测进行对比。结果表明:常规涡流检测对于凹陷的检测灵敏度较高,远场涡流检测对于一定深度的内外伤的检测灵敏度较高,高低压加热器缺陷主要集中在U形传热管外圈及直管与弯管之间的过渡段区域,可以为类似核电机组高低压加热器U形传热管的涡流检测提供参考。

For heaters in nuclear power units,U-shaped heat transfer tubes of different types of heaters were tested with different eddy current testing methods.Comparisons were conducted on conventional eddy current testing and far field eddy current testing through following aspects,such as testing principles,scheme implementations and defect analyses.Results show that,conventional eddy current testing has a high sensitivity for detecting depressions,while far field eddy current testing has a high sensitivity for detecting internal and external injuries with a certain depth.Defects in high and low pressure heaters are mainly concentrated in the outer U-shaped heat transfer tubes and the transition zone between the straight tube and the bent tube.This may provide a reference for eddy current testing of heat transfer tubes of high and low pressure heaters in similar nuclear power units.