Impurity is one of the main factors that affect the measurement accuracy of an ultrasonic heat meter. To study the effects of different impurity species and concentrations on the accuracy of heat meters, flow tests we...Impurity is one of the main factors that affect the measurement accuracy of an ultrasonic heat meter. To study the effects of different impurity species and concentrations on the accuracy of heat meters, flow tests were carried out for the suspending of calcium carbonate and yellow mud. By analyzing the attenuation characteristics of the ultrasound amplitude in different impurity concentrations and species, the influence of the impurities on the heat meter measurement accuracy is evaluated. In order to avoid the inaccuracy caused by the sediment of the reflective bottom surface, a vortex generator is put ahead of the reflective surface. According to the test, the calcium carbonate suspension with a mass concentration of 1%, which influences the heat meter accuracy severely, is used as the flow media. The influence of the vortex generator on the calcium carbonate suspension flow field in the heat meter body is studied with numerical simulations. The results of this paper provide some theoretical guide on improving the heat meter measurement accuracy when the water contains impurities.展开更多
在估计实际品质因子Q值时,因受频段选择、子波叠加、噪声干扰、非本征衰减等因素影响,容易导致Q值估计误差偏大。为此,提出基于不同阶次泰勒级数展开的含非本征衰减频域振幅比平均的Q值估计方法(Am-plitude ratio average in frequency ...在估计实际品质因子Q值时,因受频段选择、子波叠加、噪声干扰、非本征衰减等因素影响,容易导致Q值估计误差偏大。为此,提出基于不同阶次泰勒级数展开的含非本征衰减频域振幅比平均的Q值估计方法(Am-plitude ratio average in frequency domain,FARA法)。该算法首先利用参考频段内振幅比的连乘消除非本征衰减的影响;然后基于振幅因子在参考频点处的1~4阶泰勒级数展开表达式,推导适用于含非本征衰减地震记录的单频点Q值计算公式;其次,采用高、低频双参考频段结合方式削弱参考频段的影响;最后,采用主值频段内所有频点的平均化处理提高算法的稳定性。模型试验表明,采用高、低参考频段结合的模式可以显著提高所提方法的Q值估计精度,相对于对数谱面积双差值(LSADD)法,新方法受时差、时窗及噪声等因素的影响更小。实例应用表明,不同阶次的FARA法Q估计值的一致性较好,且整体大于LSADD法的Q估计值,与模型试验结果吻合,表明由新方法获得的Q值更可靠。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51276102)the Natural Science Foundation of Shandong Province(Grant No.ZR2014EEM015,ZR2011EEM011.)
文摘Impurity is one of the main factors that affect the measurement accuracy of an ultrasonic heat meter. To study the effects of different impurity species and concentrations on the accuracy of heat meters, flow tests were carried out for the suspending of calcium carbonate and yellow mud. By analyzing the attenuation characteristics of the ultrasound amplitude in different impurity concentrations and species, the influence of the impurities on the heat meter measurement accuracy is evaluated. In order to avoid the inaccuracy caused by the sediment of the reflective bottom surface, a vortex generator is put ahead of the reflective surface. According to the test, the calcium carbonate suspension with a mass concentration of 1%, which influences the heat meter accuracy severely, is used as the flow media. The influence of the vortex generator on the calcium carbonate suspension flow field in the heat meter body is studied with numerical simulations. The results of this paper provide some theoretical guide on improving the heat meter measurement accuracy when the water contains impurities.
文摘在估计实际品质因子Q值时,因受频段选择、子波叠加、噪声干扰、非本征衰减等因素影响,容易导致Q值估计误差偏大。为此,提出基于不同阶次泰勒级数展开的含非本征衰减频域振幅比平均的Q值估计方法(Am-plitude ratio average in frequency domain,FARA法)。该算法首先利用参考频段内振幅比的连乘消除非本征衰减的影响;然后基于振幅因子在参考频点处的1~4阶泰勒级数展开表达式,推导适用于含非本征衰减地震记录的单频点Q值计算公式;其次,采用高、低频双参考频段结合方式削弱参考频段的影响;最后,采用主值频段内所有频点的平均化处理提高算法的稳定性。模型试验表明,采用高、低参考频段结合的模式可以显著提高所提方法的Q值估计精度,相对于对数谱面积双差值(LSADD)法,新方法受时差、时窗及噪声等因素的影响更小。实例应用表明,不同阶次的FARA法Q估计值的一致性较好,且整体大于LSADD法的Q估计值,与模型试验结果吻合,表明由新方法获得的Q值更可靠。
