Measurement: Sensors (Nov 2020)

Electromagnetic-conductance measurement method for the flow rate and void fraction of gas-liquid two-phase flows

  • Fucheng Chang,
  • Zitu Hu,
  • Xi Li,
  • Zongrui Feng,
  • Shiyao Ni,
  • Huixiong Li

Journal volume & issue
Vol. 10
p. 100030

Abstract

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Gas-liquid two-phase flow systems are widely existed in many engineering systems and industrial processes, and measurement techniques for two-phase flows are crucial in a diverse range of engineering applications. Most of the existing measurement techniques usually brought extra resistance to the flow in the branch pipes and, to some extent, influenced the original distribution of the gas-liquid two-phase flows in the parallel T-junction system. In order to study the distribution characteristics of two-phase flow in vertically parallel T-junctions, the electromagnetic-conductance measurement method was developed to measure the void fraction and liquid flow rate of the gas-liquid two-phase flow in the branch pipes. Electromagnetic-conductance measurement technique has the advantages of high response rate, satisfactory accuracy and low disturbance on the flow field of gas-liquid two-phase flows. In order to calibrate the conductance measurement method, experiments were carried out with the liquid velocity range of 0.2–2 ​m·s-1, the gas velocity range of 0–50 ​m·s-1 and the volume void fraction range of 0–0.99. Through the calibration experiments, the relationship between the resistance value of each conductivity sensor and the volume void fraction of two-phase fluid was decided to be established as a logistic function. By the error analysis of the calibration results, 75.9% of experimental results of the void fraction in the gas-liquid two-phase flow fell within the ±20% error bands. The electromagnetic-conductance measurement method proposed in this paper could provide a reference for accurate and non-interference measurement of two-phase flow in parallel T-junctions.

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