Research of heat exchanger fouling ultrasonic testing signal analysis method based on inverse filtering and high order cumulant MUSIC spectrum estimation

Fouling of heat transfer equipments is a common problem in modern industry. Because the traditional fouling monitoring thermodynamic approach has low credibility, ultrasonic echo method is proposed to monitor fouling. Usually the fouling layer of equipment is thin, echo is overlapped and cluttered, and it is difficult to extract features from signals. Inverse filtering method is introduced to transform the hard-to-distinguish delay information in time-domain to frequency-domain information. Then signal processing method, using high order cumulant in combination with MUSIC spectrum estimation, is used to realize the fouling echo information extraction. The experiments of simulation signal and actual signal verified the effectiveness of this method.