基于时间域电磁法的金属矿采空区探测系统研制

发布时间：2018-01-01 17:35

本文关键词：基于时间域电磁法的金属矿采空区探测系统研制　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着经济发展水平的提高,国内对金属矿产资源的需求日益增大,我国的金属矿产资源虽然丰富,但大多数金属矿山因为历史原因都存在错综复杂的采空区,如果在开采作业中地下某个未知的采空区发生塌陷,则可能造成重大安全事故。因此采空区的探测至关重要。时间域电磁法是物探领域一种比较常用的方法,却并没有大规模应用在金属矿采空区探测中。为了验证时间域电磁法是否适用于金属矿采空区的探测,本文对该方法进行建模并转换为等效电路进行计算,并通过Ansoft Maxwell 3D软件构造了地下高阻球体异常模型,用来模拟采空区,通过仿真得到感应电压值与测点位置的关系曲线。从曲线上可以明显看出高阻球体异常的存在,证明时间域电磁法从理论上可以应用于金属矿采空区探测。基于时间域电磁法的可行性,本文设计了一套针对金属矿采空区探测的系统,系统包括发射模块、线圈、接收模块三部分。为了保证仪器的可靠性,对各个模块提出如下参数要求:发射模块在野外条件下能达到200V发射电压,而且发射时间、采集时间等关键参数可调;线圈尺寸应不超过m5m5?;接收模块的采集精度要达到20位,采样率要达到150k Hz,且该模块必须具备“采集”、“叠加”、“保存”等功能,采集全程要求波形能在前面板实时显示。系统的发射模块根据功能划分为参数设置、瞬态大功率电源、大功率H桥、驱动电路、MCU时序控制等单元,分别对各个单元完成设计与仿真后进行整合,制作出发射样机,经测试发射机能稳定输出最大200V的双极性脉冲信号,且脉冲宽度、频率等关键参数可通过面板上的旋钮开关进行调节。接收模块包括硬件和软件两个方面:硬件主要包括信号调理电路单元和信号采集单元,其功能是对接收信号进行调理、采集与保存,并完成AD转换;软件基于Lab VIEW平台采用“生产者-消费者”模型进行编程,为了减小噪声的干扰,软件要将接收到的数字信号进行叠加处理,并将叠加后的数据以特定文件名存储于预设的路径中。将软硬件整合后制作出接收样机,经测试接收机运行稳定,能以156k Hz采样率完成4通道采集工作,信噪比112 d B,采集精度24位。在实验室测试中仪器各项关键参数均达到设计要求。为了验证仪器的实际效果,在河南栾川三道庄钼矿区进行了野外测试,在已知地下有采空区的平台上布置一条测线,用不同的发射电压在测线上进行测量,从反演结果可以看出接收信号在已知的采空区域有明显下降。对实验过程及结果进行分析后,证明本文设计的金属矿采空区探测系统在野外探测中具有较强的功能性与可靠性,可用于对金属矿区地下0-60m的采空区域进行探测,并证实了金属矿采空区的探测深度与发射电压呈正相关的猜测。
[Abstract]:With the improvement of the level of economic development, the domestic demand for metal mineral resources is increasing day by day. Although the metal mineral resources in China are rich, most metal mines have complicated goaf because of historical reasons. If an unknown goaf collapses in the mining operation, it may cause a serious safety accident. Therefore, the detection of goaf is very important. Time domain electromagnetic method is a common method in geophysical exploration field. In order to verify whether the time domain electromagnetic method is suitable for the detection of metal mined-out area, the method is modeled and converted to equivalent circuit for calculation. The underground high resistivity spherical anomaly model is constructed by Ansoft Maxwell 3D software to simulate the goaf. The curve of the relationship between the inductive voltage value and the position of the measuring point is obtained by simulation, and the existence of the anomaly of the high resistance sphere can be clearly seen from the curve. It is proved that the time-domain electromagnetic method can be used to detect the goaf in the metal mine theoretically. Based on the feasibility of the time-domain electromagnetic method, a system for detecting the goaf in the metal mine is designed in this paper, which includes the launching module. In order to ensure the reliability of the instrument, the following parameters are required for each module: the transmitting module can reach 200V transmitting voltage in the field condition, and the transmitting time. The acquisition time and other key parameters can be adjusted; Coil size should not exceed m5m5. ; The acquisition accuracy of the receiving module should reach 20 bits and the sampling rate should reach 150 kHz, and the module must have the functions of "acquisition", "superposition", "preservation" and so on. The transmission module of the system can be divided into parameter setting, transient high-power power supply, high-power H-bridge, driving circuit and MCU timing control unit according to the function of the system. After the design and simulation of each unit are completed, the prototype is made. The test transmitter can output the maximum 200 V bipolar pulse signal stably, and the pulse width can be achieved. The frequency and other key parameters can be adjusted by the knob switch on the panel. The receiving module includes hardware and software: the hardware mainly includes signal conditioning circuit unit and signal acquisition unit. Its function is to adjust the received signal, collect and save, and complete AD conversion; The software is based on the Lab VIEW platform and uses the "producer-consumer" model to program. In order to reduce the noise interference, the software needs to superposition the received digital signals. And the superimposed data is stored in the preset path with the specific file name. After the software and hardware integration, the receiving prototype is made, and the test receiver runs stably. It can complete 4-channel acquisition at 156kHz sampling rate with 112dB signal-to-noise ratio (SNR). In order to verify the actual effect of the instrument, field tests were carried out in Sandaozhuang molybdenum mine area, Luanchuan, Henan Province. A measuring line is arranged on a platform with known underground goaf and measured on the line with different emission voltages. From the inversion results, we can see that the received signal in the known goaf domain has a significant decline. The experimental process and results are analyzed. It is proved that the goaf detection system designed in this paper has strong function and reliability in field exploration and can be used to detect the goaf area of 0-60m underground in metal mining area. The prediction of positive correlation between the detection depth and the emission voltage of the goaf is confirmed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD17;P631.325

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