Seepage Monitoring Research On Long-distance Water Transmission Pipeline Based On Noise Signal

As the basis of survival and development,water is the indispensable resource to humans.With the economic growth,water consumption of life and industries puts great pressure on the water transmission pipeline and water pipe system is being constructed consistently.Long distance pressure transmission pipeline has a series of advantages,such as smooth and reliable transmission,being free from pollution,low transportation costs,convenient management and maintenance,and effective use of land.Due to force majeure or man-made factors,it frequently causes seepage to water transmission pipelines,resulting in serious waste of water resources.It is significant for the long-distance water transmission pipeline to carry out the research on the water pipe seepage localization and obtain information such as the amount of seepage accurately and timely.Currently,in view of the water pipe seepage,acoustic seepage processing methods are adopted to detect and localize the seepage.The previous research mainly focused on urban water supply network and gas transmission pipeline,which are different from long water pipes in transmission distance,pipe materials and buried conditions et al.It is necessary to refine existing research theories and methods to be applied to long water transmission pipeline seepage monitoring research.In the dissertation,the optical fiber hydrophone with its relevant analysis instruments and equipment is adopted and water transmission pipeline seepage detection and localization method is put forward focused on the long distance,realizing efficient seepage monitoring of water pipeline and providing reference and technical support for the future projects.The main contents and achievements of the research are shown as follows:1.A wide variety of seepage data are analyzed and water pipeline seepage types and reasons are discussed.The main noise sources as the research object and the formation mechanism are identified.Research results showed that noise from the seepage position can be applied for seepage localization.2.Under different conditions,seepage noise frequency,amplitude and the effectson noise are analyzed to adjust the model parameters.It showed the noise amplitude and frequency have relations with the layout of hydrophones,seepage area and tubing pressure.The amplitude via floating hydrophone is the highest.As the hole diameter and pressure increase,the noise amplitude raise.3.Based on existing theories,the corresponding parameters are improved,and seepage model of seepage localization and seepage amount is introduced based on the water pipeline noise.Based on the MATLAB software,acoustic noise post-processing analysis software is developed.The on-site test is conducted for the models and the theoretical data are coMPared with actual results,verifying the feasibility and effectiveness of the model.4.Improved model is applied into the actual project and seepage monitoring project is verified in the middle line of the south-to-north water transfer project,providing reference for the engineering practice to monitor the pipeline seepage effectively and reduce water loss.