IN-SITU NON-DESTRUCTIVE MONITORING OF WATER FLOW IN DAMAGED AGRICULTURAL PIPELINE BY AE

摘要

Deterioration of water-flow function in a pipeline system has resulted from water-leak accidentsrndue to damage accumulation in pipe materials. The repaired pipeline system cannot be evaluatedrnof water-leak phenomena under the inner water pressure condition. Non destructive evaluation ofrnwater-flow function in pipeline system is currently in urgent demand. In this study, acousticrnemission (AE) method is applied to the evaluation of water-flow function in an existingrnagricultural pipeline, which was inspected and then repaired after water-leak accidents. At threernconditions, experiments were conducted. First, a water leak phenomenon which the pipelinernfilled full with water was investigated. Secondly, an evaluation process of water-drained fromrnfull to empty condition was made in the pipeline. Thirdly, experiments were carried out conditionrnof the pipeline was filled with water after repairing the water-leak section. AE method wasrnapplied to detecting signals of water-leak and flow under these conditions. The results show thatrnwater-leak in the pipeline system could be quantitatively evaluated by using such AE parameters,rnsuch as generation behavior and AE energy. In the third condition, AE generation behavior wasrnvaried with the situation of the pipeline until the pipeline was filled with water. AE energyrnshowed the same tendency as AE generation behavior. When an AE sensor was installed on anrnair valve, AE energy dropped temporarily as the pipeline was being filled with water. However,rnwhen water was filled up to the air valve, the increase in AE energy was confirmed. Thus, itrnbecomes clear that when a pipeline is being filled with water after the repair, the situation ofrnwater in the pipeline can be clearly identified through AE monitoring. Discharge evaluation of arndamaged pipeline system can be conducted in a short time through AE monitoring.