Heat Recovery Steam Generator

HRSGs are usually configured for an exhaust gas path with the heat exchanger tube banks. The tubes are usually supported to provide for unrestricted downward expansion, or supported by drilled tube sheets, hung from the steel structure, which also supports the boiler casing. Circulation of the water-steam mixture in the evaporators is achieved by the natural buoyant forces of the water-steam mixture in the tubes, or circulation pumps at ground level.