CT-4 Two-Phase Pressure Drop in Tubeside Condensation

C. C. Yang and J. W. Palen

This report presents a new recommended method for calculation of pressure drop during tubeside condensation. Although based on the Martinelli separated flow model, the final result is considerably different from the original Martinelli correlation. The new correlation requires different correlational constants for shear controlled and gravity controlled flows, and uses an HTRI developed flow regime parameter to select the appropriate values. Prediction of all available condensation pressure drop data is significantly improved as compared to present literature methods.

A review of the basic theory and a survey of recent literature for intube two-phase pressure drop are included, and recommended procedures for stepwise and shortcut calculations are outlined with calculated examples.