Development of ultrasonic pulse-train Doppler method for velocity profile and flowrate measurement
Development of ultrasonic pulse-train Doppler method for velocity profile and flowrate measurement
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DOI：
10.1088/0957-0233/27/11/115302
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发表时间：
2016-09
影响因子：
2.4
通讯作者：
S. Wada;N. Furuichi;T. Shimada
中科院分区：
文献类型：
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作者：
S. Wada;N. Furuichi;T. Shimada
提出了一种测量管道内流速分布和流量的新技术。与传统的超声脉冲多普勒方法相比，该方法具有速度测量范围大、测量体积小、计算量小、仪器成本低等优点。由于奈奎斯特采样定理，传统方法的速度测量范围有限。此外，以前的报告表明，较小的测量体积增加了测量的准确性。考虑到常规方法在实际流场中的应用，如工业设施和发电厂，速度范围和测量体积的问题是重要的。UPTD算法，它利用两个脉冲的超声与一个短的时间间隔和包络检测，提出。该算法计算的速度分布进行了检查，通过模拟和良好的协议，发现在所有情况下。并分析了信噪比对算法性能的影响。结果表明，UPTD在信噪比较低的情况下也能获得较高的速度剖面精度。在日本国家标准水流量校准装置上进行了实验测量，并对测量结果进行了评价。每一个检测信号形成一组两个脉冲，可以清楚地观察到包络线。结果表明，UPTD可以测量整个管道直径上的速度分布，即使速度超过可测量的速度范围。测量的流量在0.6%以下，所有流量条件的标准偏差在± 0.38%以内，这是以前报告中估计的流量测量的不确定度。总之，UPTD提供了卓越的上级准确性和速度范围的扩展。
We present a novel technique for measuring the velocity profile and flowrate in a pipe. This method, named the ultrasonic pulse-train Doppler method (UPTD), has the advantages of expanding the velocity range and setting the smaller measurement volume with low calculation and instrument costs in comparison with the conventional ultrasonic pulse Doppler method. The conventional method has limited measurement of the velocity range due to the Nyquist sampling theorem. In addition, previous reports indicate that a smaller measurement volume increases the accuracy of the measurement. In consideration of the application of the conventional method to actual flow fields, such as industrial facilities and power plants, the issues of velocity range and measurement volume are important. The UPTD algorithm, which exploits two pulses of ultrasound with a short interval and envelope detection, is proposed. Velocity profiles calculated by this algorithm were examined through simulations and excellent agreement was found in all cases. The influence of the signal-to-noise ratio (SNR) on the algorithm was also estimated. The result indicates that UPTD can measure velocity profiles with high accuracy, even under a small SNR. Experimental measurements were conducted and the results were evaluated at the national standard calibration facility of water flowrate in Japan. Every detected signal forms a set of two pulses and the enveloped line can be observed clearly. The results show that UPTD can measure the velocity profiles over the pipe diameter, even if the velocities exceed the measurable velocity range. The measured flowrates were under 0.6% and the standard deviations for all flowrate conditions were within ±0.38%, which is the uncertainty of the flowrate measurement estimated in the previous report. In conclusion, UPTD provides superior accuracy and expansion of the velocity range.