隧道支护架对核磁探测影响的研究

发布时间：2019-06-07 10:03

【摘要】：核磁共振超前探测在隧道中因受到支护架的影响,使发射电流减小,影响激发场的建立和信号的接收,以至于探测结果不精确。为了定量讨论这种影响,通过分析支护架与探测线圈物理关系、电磁场相互影响等,建立了变压器模型。简化电路模型,利用基尔霍夫电流定律建立核磁共振发射线圈的电阻增量、电感减量与隧道支护架电阻、电感的关系公式,得知发射电流增加和减少的量化分析。分析支护架与发射线圈的位置关系,推导出支护架与发射线圈的互感系数公式,根据电阻增量、电感减量以及支护架与发射线圈的互感系数,可以得到支护架的电阻以及电感。通过实验论证,实测结果与理论结果相吻合,这对后续反演提供了依据。
[Abstract]:The advance detection of nuclear magnetic resonance (NMR) in the tunnel is affected by the support frame, which reduces the emission current and affects the establishment of the excitation field and the reception of the signal, so that the detection results are not accurate. In order to quantitatively discuss this influence, the transformer model is established by analyzing the physical relationship between the support frame and the detection coil, the interaction of electromagnetic field and so on. The circuit model is simplified, and the relationship between the resistance increment of nuclear magnetic resonance emission coil, inductance reduction and tunnel support resistance and inductance is established by using Kirchhoff current law, and the quantitative analysis of the increase and decrease of emission current is obtained. The position relationship between the support frame and the transmitting coil is analyzed, and the formula of the mutual inductance coefficient between the support frame and the transmitting coil is derived. according to the resistance increment, inductance reduction and the mutual inductance coefficient between the support frame and the transmitting coil, the resistance and inductance of the support frame can be obtained. The experimental results show that the measured results are in good agreement with the theoretical results, which provides a basis for subsequent inversion.
【作者单位】：吉林大学地球信息探测仪器教育部重点实验室仪器科学与电气工程学院;
【基金】：科技部科技创新工作方法项目(3B810Z950537) 国家重大科学仪器设备开发专项(2011YQ030133)
【分类号】：U452.1

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