高精度弯管流量计的理论研究和实验验证

通过求取N-S方程数值解的方法对弯管流量计进行理论研究,得出其测量准确度不仅与传感器自身的管径、曲率半径、弯径比、压力测点位置等几何结构尺寸的准确度有关,而且还与测量使用的条件有关。特别是弯管流量计与前后直管段产生的安装偏转角、直管段管径与其自身管径的一致性等环境应用条件会对弯管流量计的高精度使用产生影响。针对上述影响因素,通过对用整体数控加工的、自身带有直管段的弯管流量计进行反复实验, 结果表明:在2σ准则下,弯管流量计可以达到0.5%的测量准确度水平;不同管径情况下,流量系数也具有良好的一致性。

The Theoretical Research and Experimental Testing on Elbow Flow Meter in High Precision

The measurement accuracy of elbow flow meter is not only related to the geometry size precision of the sensor itself in diameter, curvature radius, ratio of curvature radius and diameter, and the position of pressure tap , but also related to the condition for resting, according to the calculating N-S equations to testing elbow flow meter in theory level. Especially, the condition of the application circumstance, such as the deflection angle of installation that generated by the elbow flow and the straight section in both in front and rear sides, the consistency between diameter of straight section and the pipe diameter of itself, would influence the precision of the elbow flow meter in application as well. According to the factors motioned above, by repeatedly testing the elbow flow meter which contains straight section itself machined internally with integral NC, it could be proved that the accuracy of the elbow flow meter could reach 0.5 percent under the criteria in 2σ. Meanwhile, for the circumstance in various pipe diameters, the flow factor performed in good consistency as well.