Technical Economy Analysis of External Steam Cooler for Large Coal-fired Power Plant

In order to decrease steam superheat degree of the third extraction steam and increase absolute heat efficiency of units, this paper presents a technical solution of installing external steam cooler. the paper suggest that large coal-fired power plant adopt a series style that 33%~50%of feedwater enters into the exter-nal steam cooler and the external steam cooler be installed on the platform above No.3 high-pressure heater. It is proved by overheat economy analysis that heat consumption rate of steam turbine and coal consumption for power generation are significantly reduced, and absolute efficiency of steam turbine is also improved.