Sewage Flowrate Measurement Based on Array Ultrasonic Sensor and Entropy Analysis.

Sewage is the second water resource. The accurate measurement of sewage flowrate is an essential link in the process of sewage resource utilization. In this article, we present a novel sewage flowrate measurement method based on ultrasonic phased array sensor with multi array elements and multi acoustic beams. The flow field information in the ultrasonic scanning plane is obtained by extending the non-contact single point information detection technology to the non-contact multi-point information detection technology, and then combined with the velocity distribution characteristics of the flow field, the entropy analysis method is used to build high-precision sewage flowrate measurement models, which can be developed into a promising sewage flowrate measurement solution. A series of experiments are carried out on the array ultrasonic sensor detection system designed and built in our laboratory. The experimental results, with the combined uncertainty is 0.069 m3/h, show that this method can accurately estimate the sewage flowrate. The circled entropy-boundary layer model has excellent prediction accuracy in 7-14 m3/h range, whose relative error (RE) is less than 2% and the mean absolute percentage error (MAPE) is 0.62%, which has obvious advantages compared with the accuracy of existing flow measurement technologies in the literatures. This study offers new insights on the application of array ultrasonic sensor and entropy analysis signal processing method in sewage flowrate measurement.