Thermal power generation system and operation method thereof, thermal power generation system modification method, steam turbine equipment used in thermal power generation system, carbon dioxide separation and recovery device, overheat reducer

摘要

It becomes possible to collect an excess superheat energy of a bleed steam to be delivered from a steam turbine to a re-boiler in a feed water line of the steam turbine in a larger amount, thereby improving the efficiency of the collection. Thus, disclosed is a thermal power system comprising: a boiler (1), a steam turbine, a water condenser (20); a feed water line (101) through which feed water condensed in the water condenser (20) is delivered to the boiler; a carbon dioxide separation/collection unit (200) in which carbon dioxide is separated from a boiler exhaust gas generated in the boiler; a bleed steam feed line (102) through which bleed steam bled from the steam turbine is delivered to the re-boiler (17) in the carbon dioxide separation/collection unit (200); and a desuperheater (14) which is arranged in the bleed steam feed line (102) and can achieve the thermal exchange between the bleed steam to be delivered to the re-boiler(17) and feed water. The system enables the collection of an superheat energy of the bleed steam into the thermal cycle of the steam turbine without the need of decreasing the temperature or pressure of the steam bled from the steam turbine with a spray, and therefore enables the prevention of the deterioration in efficiency of the collection which may be caused by the bleed steam.