The Research On Strain Monitoring System Of High Temperature Pressure Pipeline And Experimental Technology

Nowadays, the industrial technology develops rapidly, and the high temperature pressure pipeline has been used more and more widely, such as in the applications of power stations, chemical plants and petroleum enterprises, etc. The safety problems of high temperature and pressure pipeline should be paid more and more attentions, and the pipeline often conveys the substance which is toxic, flammable and explosive, and is easy to have accidents such as toxic gas leak and pipeline explosion, etc. Nowadays the safety monitoring technology of high temperature pressure pipeline is still existing flaws, which is not suitable for working in high temperature such as at 300℃, so a new monitoring technology is needed necessarily.In this paper, through the analysis to the failure of high temperature pressure pipeline, the main cause of the failure can been high temperature creep damage and wall creep damage, then analyzing the life prediction model of high temperature pressure pipeline and combining with the properties of optical fiber Bragg grating(FBG), a strain safety monitoring system of high temperature pressure pipeline has been developed based on Lab VIEW software.This monitoring system is mainly composed of high temperature FBG stain sensor, fiber coupler, sm130 optical sensing interrogator, the Lab VIEW software monitoring system and GSM short message sending module. The sensing monitoring system of FBG sensors use FBG multiplexing sensing technology. The data is collected by optical sensing interrogator and conveyed to the Lab VIEW software monitoring system, then the data can be processed, and if the result triggers the alarm threshold, the GSM short message sending module will send the information to user’s phone.The monitor software system is designed and written by Lab VIEW software, it has the functions of user’s system, a data processing system and SMS warning system. The function of user’s system consists of user login and management. The data processing system’s function concludes data collection, data processing, data storage and query, and the monitoring report, etc.According to the analysis of life prediction module of high temperature pressure pipeline, and use C projective method, two warning models have been designed which includes the way of strain accumulated limit and way of strain rate overrun.Based on the need of high temperature pressure pipeline’s surface strain monitoring technology, a suitable high temperature alloy structure which is sensitive to strain has been used to package the high temperature polyimide naked FBG, and finished the FBG sensor’s encapsulation for the experiment. The computer monitoring software is written by Lab VIEW software, and the strain real-time monitoring system of high temperature pressure pipeline with FBG multi-point network technology has been developed in this paper which can work the at the range of 0~300℃.In order to verify the effectiveness and performance of real-time of the strain monitoring system of high temperature pressure pipeline based on Lab VIEW software, a FBG strain sensing experiment has been carried out. First the whole experiment system has been built,which is consisted of high temperature cabinet, high temperature FBG strain sensor, high temperature strain gage, equi-intensity cantilever beam, optical sensing interrogator, electricalresistance strain measurement, and weights. Then a strain sensing experiment on the FBG strain sensor which has been encapsulated has been carried out at the range of 0~300℃, and the results show the FBG senor in the test of strain monitoring system can work normally and stably, thus it verifies the train monitoring system of high temperature pressure pipeline can work normally and has the properties of feasibility, performance of real-time and accuracy.