Research On Typical Damage Of Large Normal Pressure Storage Tank Using Acoustic Emission Nondestructive Evaluation Method

In recent years, in order to ensure the security of oil supply in our country, anumber of national strategic oil bases are planning to build. The consequence isserious if large normal pressure storage tank takes an event of leakage accident.Therefore to strengthen the safety of large normal pressure storage tank monitoringand maintenance management is an important work. In this paper, typical damage oflarge normal pressure storage tank using acoustic emission nondestructive evaluationmethod has been studied, the main work includes:(1) Characteristic of AE signals for steel tank commonly used in stretchingprocess is researched.12MnNiVR steel used as the research object, first the AEsignals and these characteristics are obtained in the stretching process. Then AEsignals statistical parameters characteristic in the four stages is analyzed. In order toanalyze the AE signal waveform, the method of Hilbert-Huang transform is used andtime-frequency characteristics of AE signals is obtained; Based on AE signals of fourstages a damage identification method with an ambiguity function integratedcorrelation coefficient is proposed;(2) Characteristic of AE signals for steel tank commonly used in corrosion stateis researched. Based on the practical operation of large normal pressure storage tank,corrosion device is designed and AE signals in corrosion state are obtained. Thechange of AE signals parameter in actual corrosion state is summarized. The AEsignal waveforms in corrosion stages are extracted and the method of Hilbert-Huangtransform is used.Time-frequency characteristics ofAE signals is obtained;(3) Research on field test of large normal pressure storage tank and patternrecognition. The method of characteristic parameter and Hilbert-Huang transform isused in analyzing the AE signals received by field test taken in No.101largeatmospheric tank Lanshan transfer station Sinopec. The damage identification methodbased on the three ratios and the damage identification method with an ambiguityfunction integrated correlation coefficient is used in large normal pressure storagetank safety evaluation.