Prediction of pressure drop during forced circulation boiling of water

Abstract A simplified scheme is given for the calculation of pressure drop during the circulation of a two-phase mixture of boiling water and steam. The method follows that proposed by Martinelli and Nelson which has been extended to include the gravitational term in vertical evaporating tubes. Curves are given from which frictional, acceleration and gravitational losses can be estimated provided the outlet quality has been calculated from a heat balance. These curves are based directly on the experimental result of the boiler circulation research sponsored at the University of Cambridge by the Water-Tube Boilermakers' Association. An Appendix gives data for calculating the pressure drop during the two-phase flow of water and steam along an unheated tube.