Forced circulation steam generator - has flues formed by fire tube bundles in sections with different zigzag step numbers

摘要

In a steam generator of the forced circulation system for use in thermal power stations, all flues are formed by fire tube walls which are assembled in the vertical direction and curved in the horizontal direction. This creates a rigid design of high load bearing capacity which requires no supporting structure. The flues (3) of the furnace (2) has bundles of fire tubes which create zigzag channels (6) with vertical spaces (6a,6b,6c) for the hot gases. The upper bundles (7) consists of parallel tubes with three bends in plan view. The centre bundles (8) have seven bends, and the lower bundles (9) have five. Each bundle is equipped with two inlet and two outlet headers so that the tubes of each bundle are traversed by the steam in alternate directions.