Based On The Distributed Optical Fiber Temperature Sensing Monitoring Method Of The Leakage

The technology of distributed optical fiber temperature sensing system has provided anew method to study leakage monitoring of dams. It shows that the technology ofdistributed optical fiber temperature sensing system has unique advantage in leakagemonitoring. The development of this technology makes it possible for us to monitor theleakage of dams integrally, thoroughly, precisely, which have complex geologicalconditions, various topography, complex structures and bulky volume. This technologyhas been used in many engineering practice successfully and gained a lot of excellenttheoretic results and practice experience. It shows the superiority of distributed opticalfiber temperature sensing system as well. However, no matter in the theoreticalfoundation or actual circumstances, the technology of distributed optical fiber sensing isstill in the stage of developing. There are quite many theoretical and practical problemsmust be solved.In this paper, the basic principle of monitoring, through the distributed optical fibertemperature sensor system monitoring leakage model test, with the aid of somenumerical analysis and fitting of mathematical means and MATLAB, COMSOL,Microsoft Visual Studio software tools, draw some useful conclusions.The main contents that researched in this paper including:(1) Summarized the development of distributed optical fiber temperature sensorbased on the general situation and distributed optical fiber temperature sensor leakagecurrent research status monitoring technology, and summarized the advantages of thetechnology.(2) Using software tools COMSOL through the finite element analysis method, thenumerical simulation and leakage test model conditions the same condition, theestablishment of optical fiber and heat transfer medium numerical simulation model,through the finite element method to heating power, moisture content on the opticalfiber temperature and the influence of the temperature of surrounding rock wassimulated, and the results of the numerical simulation and the experimental results wereanalyzed the ratio, the leakage tests verify the correctness of the modeling methodology,feasibility and test the credibility of the data, for the speed and optical fiber to leakageof temperature rise test research to provide the basis. (3) Considering distributed optical fiber itself needs to pay for the cycle of cold andheat cycle, and affect the major indexes of the optical fiber patience and the strength ofthe optical fiber to change is given priority to, the design and test of the durability of theoptical fiber. With computer software of the test data, by fitting the patience to opticalfiber conduct qualitative analysis for future engineering application to provide thereference.(4)Through monitoring tests for leakage obtained by the test data are correspondingnumerical analysis, it is concluded that the clay, fine sand and gravel medium underdifferent heating power leakage of the speed and optical fiber temperature rise and thesame relation curves under heating power leakage speed and the relationship betweenthe optical fiber temperature curve, through the curve find out the leakage of certaintemperature rise speed and optical fiber relationship, using mathematical method andsoftware tools, in the analysis of data processing, and on the basis of fitting out speedand temperature of the optical fiber leakage the relation curve between the, expression,for the further research and the optical fiber leakage rate of the relationship between thetemperature provides theory basis.(5) In view of the leakage monitoring test in DTS data is very much, rely on chartin the form of seepage velocity response, the intuition is not very strong, so that thegrasp of leakage velocity cannot intuitive, timely, in order to solve this problem, basedon the simplified leakage monitoring during the monitoring process, based on thedevelopment of distributed optical fiber temperature sensing technology to seepagemonitoring method for seepage flow monitoring system.