Exerimental Study On Smart Sleeve Design For Water Supply Pipeline And Repair Of Leaky Pipeline

China’s urban economy is in a stage of rapid development.The increase in population and the increased demand for water continue to increase the burden on urban water supply networks.The problem of high leakage rate of urban water supply pipelines caused by the aging of old water supply pipelines is becoming more and more serious,not only for drinking water resources,it does great harm to the surrounding soil environment.Relevant research shows that for small and medium diameter water supply pipelines,the probability of occurrence of small-aperture pipe explosion is relatively high,and the existing pipeline repair technology has strong pertinence and high cost,and the existing pipeline leakage monitoring equipment also has problems such as insufficient accuracy and lack of directivity.Aiming at the defects of round hole-shaped water supply pipelines,the project designed outsourcing pipe fittingssmart sleeves that can realize the rapid repair function of pipelines and the online monitoring function of leakage,and carried out the performance characterization test and intelligence of water-activated materials for repairing pipeline leakage and actual water test of the sleeve.Design the smart sleeve structure according to the characteristics of the smart sleeve,calculate the thickness of the outer wall of the sleeve and the size of the fixing bolt,and construct the shape of the intelligent sleeve.Compared with the transmission sensitivity,equipment cost,signal transmission stability and other factors of fiber grating sensors,capacitive sensors and piezoelectric thin-film sensors,piezoelectric thin-film sensors are preferred as the transmission elements of the online monitoring system;the water-activated material in the smart sleeve is selected as a double-layer overlapping overlay arrangement,the sensor placement point is selected between the two layers of material,and the sleeve ear plates and the water activation are selected at the same time The point where the material is attached to the inner wall of the sleeve is used as an auxiliary point;the smart sleeve can ensure good stability at an external pressure of 0.60 MPa and a negative internal pressure of 0.001 MPa,which proves that the smart sleeve has sufficient strength.By analyzing the changes in water absorption and water immersion mechanical properties of nitrile rubber,neoprene rubber,and natural rubber substrates,nitrile rubber is preferred as the substrate for water-activated materials,physical blending method is used to prepare nitrile rubber water-swellable rubber.Formulate design,complete hydrophilic modification of nitrile rubber,rubber raw material mixing and vulcanization process,and prepare water-activated materials.Through the analysis of the mechanical properties and water pressure resistance of the water-activated material after immersion in water,it was found that the tensile properties and tear resistance of the water-activated material decreased by 10% on average,and the double-layer material’s water pressure resistance could reach 0.58MPa;comprehensive Analysis of multiple sets of immersion tests.The water-activated material has a saturated water absorption expansion rate of approximately 410% and a water immersion mass loss rate of approximately 11%.It has good weather resistance and chemical resistance,and has the materials required for smart sleeves.Characteristics and corrosion resistance.The influence of the material on the conventional and specific indicators of water quality after immersion in water was analyzed.After 72 hours of immersion in the material,the turbidity increased by 0.16 and the p H increased to 7.5~8.0.The residual zinc and sulfide in the water can be ignored for the water supply network system Excluding,it can meet the sanitary conditions of drinking water.In order to verify the practicability of the smart sleeve,the static pressure test and the dynamic water flow test were used to analyze the possibility of characterizing the pipeline leakage signal and the alarm rate of leakage.The strain value at the monitoring point under static pressure increases with a large area of water absorption components in the water-activated material,the fluctuation amplitude gradually smoothes,and the strain curve tends to be stable.When the pressure in the pipeline changes,the characteristics of the strain curve change significantly,which is sufficient to characterize the pipeline.Leakage signal;in the dynamic pressure test,within 2 hours of the actual leaky pipeline with the smart sleeve installed,the water-activated material has obvious effect on the repair of the pipeline,the repair rate is higher,the fluctuation value of the strain value of the monitoring point increases slightly,and the amplitude changes Reduced,the material’s water absorption tends to saturation,and the smart sleeve has a higher leak repair rate.In this project,a smart sleeve housing and water-activated materials in the sleeve were constructed.The leakage signal data transmission system was optimized.The physical and chemical properties of the material were studied and practical application tests were conducted.It was used for rapid repair and online monitoring of local leakage of the water supply pipeline.The technology provides a certain theoretical basis,which can effectively control the loss of the water supply network at a lower cost,protect pipeline environment and save water resources.