| Water are precious resources, human will not survive without water. However, thefree water as water disasters brings incalculable casualties and economic loss forpeople in the process of tunneling and mining. Therefore, developing the research ofadvanced prediction of water disasters could effectively curb water gushing andreduce the human and economic losses, which is a urgent major scientific problem tosolve. Magnetic resonance sounding detection technology (Magnetic ResonanceSounding, hereinafter referred to MRS) is currently the only way to directly detectwater and pioneered the application of geophysical methods which applications ofnew field of MRS technology. MRS techniques take advantage of hydrogen nuclei inthe water when the frequency of the radio frequency magnetic field meets certainconditions, under work together of the stable magnetic field and radio frequencymagnetic field to absorb the energy of radio frequency magnetic field, finally produceresonance transition. This method uses artificially electrify to the coil laying on thedetection surface with larmor frequency to format radio frequency magnetic field sothat the hydrogen protons resonate transition. Receiving coil with the transmitter coilseparation to receives induced electromotive force signal through MRS signalproduction. The front of hydrological information can be got through signalprocessing. At present the MRS of advanced detection face many difficulties which itfirst is applied in tunnel/mine water disaster detection. This article mainly researchMRS coil of advanced detection is seriously affected by the supporting frame intunnel, makes the excitation current decreases, and affects the establishment of theexcitation field and signal receiving so that the detection result is not accurate. Inorder to solve this problem, combining with transformer model and using thekirchhoff’s current law to establish nuclear magnetic resonance transmitter coil of resistance increment, inductance reduction and tunnel support relationship formula ofequivalent resistance and inductance. To calculate the mutual inductance ofsupporting frame and transmitter coil through the above factor. According to theresistance increment, inductance reduction and the mutual inductance of supportingframe and transmitter coil, so supporting frame of the equivalent resistance andinductance can be got. By experiment demonstrating, the measured results comparedwith the calculated results, make every effort to provide a basis for MRS signalinversion and detection results more accurate.Based on the “twelfth five-year” national important scientific instrumentsdeveloped special “Water disasters (mine/tunnel) direct detection instruments andequipment development and application”(2011yq030133) project of the “Watertunnel disaster magnetic resonance (NMR) associated with transient electromagneticadvanced detector data processing” corpus as the backing, the this article mainresearch content is as follows:The first chapter is the introduction of this article, introduced the nuclear magneticresonance (NMR) water at home and abroad present situation, significance.Thisarticle illustrates the nuclear magnetic resonance (NMR) water in the economy, thehumanities, the importance of scientific research,puts forward the problem of thedifficulties of high technology and science, points out that the focus of the research inthis paper.The second chapter introduced the nuclear magnetic resonance (NMR) frommacroscopic and microscopic aspects of advanced detection principle of nuclearmagnetic resonance (NMR) water instrument (transmitter and receiver) works. Inaddition, this chapter lists the subject of the facingproblems,challenges and tasks.The third chapter analysis the effects of the tunnel supporting frame to nuclearmagnetic resonance (NMR) detection, the related experiment model was established,related theory formula is deduced, the supporting frame and the relationship betweenthe detection coil, calculate the mutual inductance between the two formulas, lay afoundation for subsequent processing.The fourth chapter based on the supporting frame and nuclear magnetic resonance (NMR) receiver coil model, establish relevant experiments, it is concluded that aseries of data, application of actual data analysis of tunnel supporting frame of nuclearmagnetic resonance (NMR) to detect the influence of the reception, for practicaldetection direction is presentedThe fifth chapter based on two advanced detection data acquisition, verify theestablishment of the model in this paper and the derivation of formula and that iscorrect.The sixth chapter summarizes the full article, and gives the suggestions tothe nextstep of work (increase the magnification, improve equipment stability, calibration ofinversion kernel function). |
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