Two-Phase Flow Pressure dro‎p Calculation Using Homogeneous Equilibrium Model

Although two-phase flow is frequently encountered in various locations of the process plants, there is no a generally accepted and verified two-phase flow model that may be used to size lines for such conditions. An obvious example is condensate water return lines. The API method used in this study is based on the homogeneous equilibrium flow assumption, that is, equal velocity and equal temperature in both liquid and vapor phases. Moreover, DIERS method was used to verify and clarify the HEM approach to calculating the pressure drop in two-phase regimes. The objective of this study is to introduce a solution for process lines design during different flashing scenarios. Applying API method, this study can find the two-phase line pressure drop and upstream pressure, while, by using DIERS method, one could realize that for a specified length of pipe how much two-phase flow could pass through when the pressure drop is just the same as that in the API model.