A once-through vertical tube supercritical evaporator for heat recovery steam generators.

摘要

An once-through steam generator (OTSG) coil comprising a plurality of vertically arranged meander lines 90 in a horizontal heat recovery steam generator (HRSG) replacing a conventional natural circulation HP evaporator to produce supercritical steam 52 and methods are disclosed. The OTSG includes a lower equalization header system 130 that enhances system stability in multiple operating conditions. The equalization header allows partial fluid flow from the lower serpentine curved channel 12 to the equalization header 130 via the equalization line 125. A flow restricting device in the meandering line; drainage structure from the meandering line via the equalization header; a drainage expansion part for receiving stress; and a drainage bypass connection; upstream via the meandering line And downstream flows, mixed flow directions, and longitudinal staggered directions are disclosed.