Application of Ultrasonic Method on Particle Concentration in Gas-Liquid Two-Phase Flow

To achieve optimal control of the process and reduce energy consumption, particle size measurements and concentration (or wetness) in gas-liquid two-phase flow is very significant. For example, the wet steam in the latter stages of the low pressure (LP) environment in steam turbines can yield decreased efficiency and turbine blade erosion in large power plants, thereby affecting the efficiency of electricity generation. It is therefore critical to perform an on-line measurement of wet steam in the last stages of LP steam turbines. A low-frequency ultrasonic wave was chosen as an information carrier of droplet concentration; the ultrasonic method has the ability to penetrate a high concentration of wet steam. To investigate the fundamentals of the measurement, wet steam was replaced by a two-phase system of water droplets (generated by a humidifier) in the air. The environment during the LP, final stages observed in steam turbines was simulated to measure the concentration of droplets by the ultrasonic method.