Research On The Monitoring System Of The Expansion Joint Damage For Underground Heating System

According to the problem of pipe fluid leakage of bellows expansion joint,this paper analyzes the reasons for the failure of bellows expansion joint.The crack and fracture surface morphology and composition were analyzed based on macro detection,XRD,SEM,EDS and other testing methods.Damage cause of expansion joint in underground heating pipe network is coupling effect of deformation martensite in stainless steel,residual stress and chloride ion in the medium.On this basis,we developed a network of underground heating expansion joint damage-line monitoring system.Take the underground heating pipe network of Datang Weihe Thermal Power Plant as research objects.The soil near expansion joint is sampled,According to the soil erosion classification,the map of soil erosion along the pipeline network is drawn..the system of expansion joint damage for online monitoring is designed for an underground heat pipe network in service or new two cases.The device is based on the microcontroller STC89C54RD+,there are five main modules : Temperature acquisition module,Conductivity detection module,Vibration Acceleration Test Module,Level test module and remote monitoring module and so on.Temperature acquisition module uses a 4 channel temperature sensor,at different points of the expansion joint acquisition timing discriminating temperature is bulking agent leak case;Conductivity detection module is mainly used for corrosion rate of expansion joint conductance;Acceleration Test vibration acceleration sensor module analyzes the impact of vibration on the expansion joint Expansion Joints,Including road vehicle vibration,expansion joint itself shake;Level test module analyzes the impact of water level by the level of expansion joints;Remote monitoring module will send test data through the GPRS network to the server and realize remote monitoring.Compare the traditional method,the proposed method(ACCLN)is better than it.Recognition accuracy is 96.3%.The system of the underground heating network monitoring alarm expansion joint damage is applied for a Power Plant,and it has a good effect.