基于声波衰减模型对液体管道泄漏位置的极大似然估计

The traditional acoustic attenuation positioning model needs determining pipeline operation parameters before positioning so as to calculate parameters involved in the attenuation model. Here, to solve this problem, a new sensor arrangement scheme was proposed, i.e., two sensors being placed in upstream and downstream of leakage point, and attenuation parameters being obtained with ratio values of experimental signal amplitudes between upstream and downstream sensors. The signal processing method of variational mode decomposition (VMD) was used to denoise experimental signals, and effects of different leakage diameters of 3, 6, 8, 10, 12, 15, 20, 27 mm and different detection distances on leakage signals were studied. Finally, MLE was used to do leakage positioning based on the attenuation model. The results showed that the proposed method can effectively locate leakages under conditions of different leakage calibers and different sensor positions; its positioning effect is better than that of the time difference method, and its error is within the range of 0~15%; the positioning error of knocking experiments is less than 7% to prove the effectiveness of the proposed method.