Superheater and reheater tube arrangement for heat recovery steam generator

摘要

A heat recovery steam generator (HRSG) which contains multiple superheater and reheater tube units, each unit including an upper (32,36) and lower (34,38) header connected pressure-tightly together by a plurality of vertically-oriented tubes (33,37) provided in alternate parallel banks, with the tubes of adjacent units being provided in an internested arrangement. Each superheater and reheater unit contains primary straight tubes (33,37) and secondary bent tubes (33a, 37a) which are offset from the primary straight tubes in a direction perpendicular to the upper and lower headers and parallel to the direction of hot gas flowing transversely past the internested tubes. The ratio of number of superheater tubes to reheater tubes in each row of tubes is provided in proportion to the desired heat transfer from the hot combustion gas to the superheated or reheated steam passing through the tubes in the generator assembly.