煤体中超声波参数的实验研究

An experimental research on ultrasonic parameters of coal

  • 摘要: 采用声发射实验技术对大安山无烟煤与三河尖肥煤的超声波波速、衰减系数、超声波的时域特征和频域特征进行了研究。研究结果表明,受空隙率和含水率等的影响,无烟煤中的平均波速大于肥煤中的平均波速,其衰减系数平均值低于肥煤的衰减系数平均值;超声波的时域特征和频域特征受煤的品质和波形频率的影响,无烟煤的主频幅值大于肥煤,衰减周期小于肥煤,并且随着波形频率的增加,衰减时间下降,透射波形的能量更加聚集于主频。这些结论可为采掘前煤炭品质和种类的定性提供理论依据。

     

    Abstract: Ultrasonic velocity, attenuation coefficient, time domain and frequency domain features in anthracite coal of Daanshan and fat coal of Sanhejian were studied by acoustic emission experimental techniques. Research results indicate that affected by voidage and moisture content, the mean wave velocity in anthracite coal is larger than that of the average velocity in fat coal, and the mean value of its attenuation coefficient is lower than that of attenuation coefficient in fat coal.Time domain and frequency domain features of ultrasonic are influenced by coal quality and waveform frequency,anthracite has greater amplitudes of main frequency and shorter decay period than fat coal.When the wave frequency increases, the decay time decreases and energy of transmission waveform is more gathered in main frequency. These conclusions can provide theory basis for determination of coal quality and type before coal mining.

     

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