Two-Phase Pipe Hydraulics and Pipe Sizing

This particular course entitled “Two-Phase Pipe Hydraulics & Pipe Sizing” under the specialization entitled “Design of Industrial Piping Systems” is mainly aimed at predicting the two-phase total static pressure drop in a given piping system when both gas and liquid flow through it concurrently. Pressure drops including heat transfer coefficients depend on two-phase flow regimes since two-phase patterns and local internal structure are different for different flow regimes. Therefore, the formation of various two-phase flow regimes in horizontal and vertical pipes is to be known to the designer, and at the same time, the influence of bend on the formation of two-phase flow regimes in upstream and downstream pipes should also be known. The presence of a bend is inevitable in the piping systems of a plant and its presence restricts the formation of certain two-phase flow regimes commonly found in individual horizontal and vertical pipes for the given flow rates of gas and liquid and pipe diameter. Surprisingly, bend allows the formation of slug flow regimes in both horizontal and vertical pipe runs of a piping system. This is a nerve-wracking issue for the designer since the slug flow regime harms the piping system and in some situations, the slug flow regime becomes the main cause of the failure of the piping system. Therefore, the designer should be cautious during the design of two-phase piping systems and avoid the slug flow regime formation at any cost while designing the two-phase piping system. Looking into the severity of two-phase flow on the piping system integrity, the present course focuses on the formation of two-phase flow regimes in horizontal and vertical pipes and their identification based on gas and liquid flow rates using two-phase flow pattern maps. Next, the course focuses on the effect of bends on two-phase flow regime formation in both upstream and downstream pipelines as piping systems are made of connecting straight pipe runs using bends. F