Research On Multichannel Ultrasonic Detection Technology For Fouling In Heat Exchanger Tubes

Heat exchange equipment is widely used in various industries,including electric power,aerospace,and chemical,as well as in daily life.However,abnormal fouling in heat exchange equipment can cause a direct reduction in heat exchange efficiency and even lead to safety accidents.Thus,establishing a real-time detection system for fouling in heat exchange pipes is crucial.The Ultrasonic Time-Domain Reflection method is a common scheme for detecting heat exchanger fouling,but its echo signal often has interference and overlap due to the rough internal structure of the detection target and complex working conditions,making it difficult to obtain accurate Time of Flight and affecting the accuracy of fouling thickness measurement.Therefore,this paper presents research on a multi-channel ultrasonic detection technology for heat exchanger pipeline fouling.Firstly,the paper analyzes the heat exchanger pipe fouling detection system and scheme and introduces a multi-channel small-angle oblique incidence to improve the ultrasonic time-domain reflection method.A mathematical model is built,and the feasibility of the scheme is analyzed from the perspective of echo energy change and echo separation effect,and the system of the improved detection scheme is designed.Secondly,the paper builds a finite element simulation model based on the actual detection scheme and proposes a teaching and learning optimization algorithm improved by chaos mapping and spiral search,combined with the matching tracking algorithm to perform sparse decomposition and crossover time acquisition of the dirt ultrasonic detection signal.Finally,a weighted average method is designed to study the fusion of fouling thickness data of heat exchange pipes.The results show that the multi-channel oblique incidence method proposed in this paper not only increases the information acquisition channels and improves the reliability of measurement results but also weakens the mutual mixing problem between echoes with the increase of angle.The improved Teaching Learning Based Optimization combined with the matching tracking algorithm can effectively extract the features of the ultrasonic detection signal affected by noise,and the data fusion processing method is appropriate.Under normal conditions,the multi-channel oblique incidence detection scheme of this paper can improve the accuracy of the results,and when the previous scheme cannot be detected normally,the scheme proposed in this paper can still obtain relatively accurate results,which improves the stability and reliability of the measurement results.In summary,this study and its further improvement can provide a new technique for the detection of heat exchanger pipe fouling thickness and have a good application prospect for the direction of ultrasonic thickness measurement of multilayer media.