DUAL ENHANCED TUBE FOR VAPOR GENERATOR

摘要

A heat exchange assembly for generating steam from a second medium to be used to drive a steam turbine for generating electricity or for other process, includes a tube having a longitudinal axis and an inner wall and an outer wall. The outer wall includes a plurality of spaced fins oriented generally perpendicular to the longitudinal axis. The inner wall defines a preheat zone and a dual phase zone. The preheat zone defines a helical rib configured to provide swirling motion and increase heat transfer surface area to liquid entering the tube increasing heat transfer from the tube to the liquid. The dual phase zone is spaced from the preheat zone and defines a helical rib configured to provide swirling motion to steam and liquid passing through the dual phase zone increasing heat transfer from the tube to the steam and liquid while preventing vapor stagnation and film boiling.