Research On Mining Detection Of Mrs With Minor Loops

With the development of NMR detection technology, the NMR technology have matured in China.As the only physical method of finding water, it is mainly used in the ground finding water.But reffering to coal mining disaster and water tunnel detection,it is still infancy.Relying on the national "twelfth five-year" major scientific equipment development projects " Development and Application for Disaster Water(tunnel/mine) direct Detection Equipment ", this paper uses multi-turn minor loops working device probing for coal mine/tunnel disasters and water finding.Through NMR method experimental research on the ground and underground, using the actual data on the ground, and comparing the underground and ground noise,since the underground tunnel NMR system is closer to the metal, cables, etc., the underground signal strength of MRS receives greater noise, weaker anti-interference ability of the instrument and lower data signal to noise ratio. By using magnetic source emitting device,we compare circular, rectangular, and "8" shaped loop receiving devices,and the results is that whether it is underground or ground, "8" shaped loop devices receives the best noise reduction and the highest signal to noise ratio; We can first use "8" shaped loop devices to tile floor, then constantly changing direction,and we can find the best noise suppression direction, obtain a higher signal to noise ratio by detecting in a noisy complex environment area. Research on the results of simple stack, stack on the threshold and weighted stack, and weighted stack is better than the other two methods;To further improve the signal to noise ratio, the threshold stack can be superimposed with the weighted stack combination. Propose the best method of noise suppression based on the processing method of noise and the actual data processing: "8" shaped loop receiving devices+a threshold stack+Weighted stack+(adaptive notch) + low pass filtering.In order to carry out small loops of magnetic resonance to detect underground experimental research, using emitting device of rectangular magnetic source and a receiving device for detecting an experimental study on the ground,by changing the angle between the transmitting and receiving coils,namely change in the angle between the magnetic field and artificial geomagnetic field in one side of the coil axis. We study signal response characteristics of MRS and contrast inversion results, MRS strongest signal when the artificial magnetic field and the earth’s magnetic field direction angle is 90 °;According to the results of ground tests and the application of the above-described MRS signal processing method of underground data processing, we can transient electromagnetic method in combination with magnetic resonance method, carry out underground water storage experiment.The artificial magnetic field and the earth’s magnetic field direction angle is 90 by setting the emission direction of the magnetic source,then we use the method of transient electromagnetic to probe and find low resistivity anomaly point on the potential cross-sectional view, and it is the strongest and significantly higher than the other points; Then using the method of magnetic resonance to detect and verify outliers, the water content is large, up to 80% in the detection point corresponding to the depth of the probe; While in dry roadway pilot study, the inversion results for the water content is very low, only up to 4%. The outcome of the case of anhydrous than the case of water is low twenty times, showing that the method of the magnetic resonance detecting the reaction of the underground water storage is sensitive.Based on multi-turn small loop NMR pilot study underground, we combine with underground transient electromagnetic method and magnetic resonance method to verify the validity and accuracy of this method,and it is provided for reference that goaf water probe for the future application of magnetic resonance method.