Experimental Study of Liquid Holdup of Liquid-Gas Two-Phase Flow in Horizontal and Inclined Pipes

This paper aims to identify the model that can accurately predict the liquid holdup under specific conditions. For this purpose, 431 sets of test data were obtained from a 60mm-diameter pipe and a 75mm-diameter pipe, and six existing models were evaluated against these data with the pipes in the horizontal direction or at small inclined angles. Three statistical parameters were introduced to select the best-performing model. The test data were also adopted to explore the effects of pipe diameter, gas-liquid ratio, liquid types and pipe inclination on liquid holdup. It is concluded that he modified-Hughmark correlation boasted the best accuracy for air-water mixture in the horizontal direction and at small inclination angles, while the Beggs-Brill model outperformed the other models for white oil-air flow; the increase in liquid holdup is proportional to pipe diameter at the same gas-liquid ratio; as long as the gas-liquid ratio is lower than 100, the inclined angle in the range of 0 similar to 30 degrees had little effect on liquid holdup, and the effect gradually decreased with the increase in the gas-liquid ratio; the liquid holdup is positively correlated with the viscosity and the content of heavy components, and negatively with density; the gas-liquid ratio had a great impact on liquid holdup. The research findings provide a valuable reference for studies in similar fields.