探头局部扰流对超声流量计测量结果影响

Influence of probe disturbance on the measurement results of ultrasonic flowmeter

插入式探头安装方式会对超声流量计内部流场产生扰动,进而影响测量结果。在高压空气流量标准装置上对DN100 mm和DN200 mm的气体超声流量计进行标定,结果显示探头局部扰流对超声流量计会产生负向误差,管道口径越小,局部扰流引入的误差越大。DN100 mm超声流量计在3~27 m/s的流速范围内的测量误差在–1.5%~–3%之间,而DN200 mm的超声流量计在1.4~13 m/s的流速范围内的测量误差在–1.2%~–2.1%之间。分析不同压力、不同流速下探头局部扰流对超声流量计测量结果的影响规律,并基于流速和测量误差对实验结果进行曲线拟合,提供了拟合曲线的数学模型。

The installation of the inserted probe will disturb the internal flow field inside the ultrasonic flowmeter,which will affect the measurement results.The gas ultrasonic flowmeter of DN100 mm and DN200 mm was calibrated on the high-pressure air flow standard device.The results show that the local disturbance of the probe will produce negative error on the ultrasonic flowmeter.The smaller the pipe diameter,the greater the error introduced by local disturbance.The measurement errors of the DN100 mm ultrasonic flowmeter were between –1.5% and –3% in the flow rate range of 3-27 m/s,while the measurement errors of the DN200 mm ultrasonic flowmeter were between –1.2% and –2.1% in the flow rate range of 1.4-13 m/s.The influence of probe disturbance on the measurement results of ultrasonic flowmeter under different pressure and flow rate was analyzed,and the curve fitting of experimental results was made based on velocity and measurement error,and the mathematical model of fitting curve was provided.