采用射线法对垂直上升管环状流的研究

Study of the Annular Flow in Vertical Risers by Using Ray Methods

讨论了单束伽马射线测量垂直上升管环状流截面含气率及流型演变。快关阀门法用于标定平均截面含气率,并与射线法两种计算公式进行了比较,线性公式和对数公式误差分别在±6.2%及±7.1%以内。根据截面含气率及液相的分布确定垂直上升管环状流动演变共经过不均匀分布区、相对稳定区和断层区3个区域,而射线法截面含气率分布图和两种公式的相对误差大小可以反映环状流的演变过程。实时拍摄图片证明了射线法探测结果的准确性。

Discussed were the void fraction in a section of a vertical riser in annular flow measured by a single beam of γ-ray and the evolution of the flow pattern.The quick closing valve method was used to calibrate an average void fraction in a section and compared with two calculation formulae of the ray method.The errors as calculated by using the linear and logrithm formula were within a range of ±6.2% and ±7.1% respectively.Based on the void fractions in the section and the distribution of the liquid phase,the evolution of the annular flow in the vertical riser was determined to pass through the following three zones,namely,non-uniform distribution zone,relatively stable zone and fault zone.The chart showing the distribution of void fraction in the section by using the ray method and the magnitude of the relative error as calculated between the two formulae can reflect the evolution of the annular flow.The real-time photos verified the accuracy of the results detected by using the ray method.