An Evaluation of the Effect of Twisted-Tape Swirl Generators in Two-Phase Flow Heat Exchangers

Abstract

Correlations covering all modes of single- and two-phase heat transfer with twisted-tape swirl generators have been incorporated into a computer program that predicts the effect of twisted tapes on the heat duty in fluid-to-fluid once-through vapor generators. These Results are compared with those from axial flow once-through vapor generators operating at the same inlet conditions. Pumping power and pressure drop with and without swirl generators are compared. The correlations used satisfactorily predict the performance of both types of heat exchangers. Significant area, pressure drop, and pumping power reductions are possible using twisted-tape swirl generators; almost the entire area reduction is attributable to the suppression of the critical heat flux condition.