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AssigneeWestinghouse Electric Corp.
InventorRichard M. Lee
Estimating the term…
In a single cycle combustion turbine power plant, a dry catalytic NOx removal module is disposed in the turbine exhaust stack. A waste heat exchanger system includes an economizer coil and a pair of evaporator coils on upstream and downstream sides of the NO.sub.x removal module to generate steam for injection into the turbine combustors. Bypass stacks across the coils are damper controlled to regulate the exhaust gas temperature at the entry to the NOx removal module. The compressor inlet guide vanes are closed to increase exhaust gas temperature as required after the upstream evaporator bypass flow reaches zero and no longer controls gas temperature. If the inlet guide vanes reach the fully closed position, reductant injection flow is shut off to terminate the NOx removal process under low exhaust gas temperature conditions. A plant afterburner is operated to add heat to the exhaust gas if gas temperature is too low.
Apparatus for recovering heat energy and for removing NOx from the exhaust combustion gas in a single cycle combustion turbine power plant having an exhaust gas duct means, said apparatus comprising NOx removal means for mixing a reductant with the exhaust gas and for generating a catalytic reaction which removes NOx from the exhaust gas within a predetermined gas temperature range, a waste heat recovery system including an economizer coil disposed in said duct means downstream from said NOx removal means and a feedwater supply system for said economizer coil, a steam drum supplied by said economizer coil, a modulating evaporator coil disposed upstream from said NOx removing means and supplied by said steam drum, another evaporator coil disposed downstream from said NOx removing means and supplied by said steam drum, said evaporator coils supplying steam to said steam drum, means for sensing exhaust gas temperature upstream from said NOx removing means, a bypass stack disposed across said modulating evaporator coil, movable damper means for diverting exhaust gas flow from said duct means through said bypass duct, means for positioning said damper means in response to said gas temperature sensing means to hold the exhaust gas temperature within the desired NOx removal range, and means for receiving steam from said steam drum to make production use of the energy therein.
Dependencies are inferred from the claim text.