Applicability of hybrid ultrasonic flow meter for wide-range flow-rate under distorted velocity profile conditions
Applicability of hybrid ultrasonic flow meter for wide-range flow-rate under distorted velocity profile conditions
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DOI：
10.1016/j.expthermflusci.2018.01.032
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发表时间：
2018-06
影响因子：
3.2
通讯作者：
Ei Muramatsu;H. Murakawa;Daiki Hashiguchi;K. Sugimoto;H. Asano;S. Wada;N. Furuichi
中科院分区：
文献类型：
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作者：
Ei Muramatsu;H. Murakawa;Daiki Hashiguchi;K. Sugimoto;H. Asano;S. Wada;N. Furuichi
在渡越时间超声波流量计（TOF）中，流量是从两个超声波换能器之间的超声波脉冲的渡越时间导出的。要将通过时间转换为流速，需要一个剖面系数（PF）。由于PF在很大程度上取决于速度剖面，因此PF的精确校准对于TOF的准确性至关重要。因此，需要进行现场校准，称为现场校准。在这项研究中，一个混合的超声波流量计，有助于校准TOF使用超声波多普勒测速仪（UDV）的建议，通过整合管道的横截面积的速度分布进行现场校准。为此，研制了一种新型的混合式超声波流量计系统。使用传统UDV测量的最大流速显著低于使用TOF测量的最大流速。因此，开发了一种系统来测量更高的速度和流量。该系统是新颖的，渡越时间和速度剖面可以同时测量使用去混叠方法。为了评估速度分布对PF的影响，在宽范围的流速条件下进行了实验，否则无法使用传统的UDV来实现。为了评估管道中速度分布的影响，在试验段上游8D处放置了障碍板。采用放射状排列的测量线。实验结果表明，增加测量线的数量并没有提高飞行时间的准确性。另一方面，即使在扭曲的流动条件下，也可以使用所提出的UDV通过测量速度分布来准确地获得流量。此外，根据使用建议的UDV获得的流速校准PF是可行的。
In transit-time ultrasonic flow meters (TOF), the flow rate is derived from the transit time of an ultrasonic pulse between two ultrasonic transducers. To convert the transit time into flow rate, a profile factor (PF) is required. Because the PF strongly depends on the velocity profile, a precise calibration of the PF is essential to the accuracy of the TOF. Hence, a field calibration, referred to as on-site calibration, is desirable. In this study, a hybrid ultrasonic flow meter that helps calibrate the TOF using ultrasonic Doppler velocimetry (UDV) is proposed for on-site calibration by integrating the velocity profiles over the cross-sectional area of a pipe. Thus, a new system of hybrid ultrasonic flow meter was developed. The maximum flow rate measured using a conventional UDV is significantly lower than that measured using the TOF. Therefore, a system was developed to measure higher velocities and flow rates. The system is novel in that the transit time and velocity profile can be simultaneously measured using a de-aliasing method. To evaluate the influence of the velocity profile on the PF, experiments were conducted under a wide range of flow-rate conditions, which otherwise cannot be implemented using the conventional UDV. To evaluate the influence of the velocity profile in the pipe, an obstacle plate was placed at 8Dupstream the test section. Radially arranged measuring lines were employed. The experimental results show that increasing the number of measuring lines did not improve the accuracy of the TOF. On the other hand, the flow rate could be accurately obtained using the proposed UDV by measuring the velocity profile even under distorted flow conditions. Furthermore, the calibration of the PF based on the flow rate obtained using the proposed UDV was found to be feasible.