Salinity Independent Flow Measurement of Vertical Upward Gas-Liquid Flows in a Small Pipe Using Conductance Method

Area of Science:

• Fluid mechanics
• Multiphase flow measurement
• Sensor technology

Background:

• Gas-liquid two-phase flow measurement is complex due to phase distribution, slippage, and varying flow structures.
• Changes in water salinity alter conductivity, further complicating multiphase flow measurements.
• Existing methods struggle with accuracy when salinity fluctuates.

Purpose of the Study:

• To propose a novel methodology for gas-liquid two-phase flow measurement using the conductance method, specifically addressing salinity variations.
• To develop a conductivity detection method ensuring linear sensor output despite conductivity changes.
• To establish new measurement models for water holdup and flow velocity that are independent of salinity.

Main Methods:

• Developed a suitable conductivity detection method for linear sensor response.
• Designed and implemented a combined sensor system including water holdup, velocity, and conductivity sensors.
• Created new water holdup and flow velocity measurement models accounting for flow complexities and salinity changes.

Main Results:

• A conductivity detection method was proposed that maintains high and constant sensor resolution across varying water conductivity.
• The combined sensor system was experimentally validated in a 20 mm pipe for gas-water two-phase flow.
• Novel measurement models were established, achieving salinity-independent water holdup and flow velocity measurements for the first time.

Conclusions:

• The proposed methodology effectively addresses the challenges of measuring gas-liquid two-phase flow with variable salinity.
• The developed combined sensor system and measurement models offer a robust solution for accurate flow parameter determination.
• This work represents a significant advancement in multiphase flow measurement technology, enabling reliable performance across diverse salinity conditions.