Application of Flue Gas Deep Cooling System in 1 000-MW Ultra-Supercritical Units

In order to fully utilize the waste heat from flue gas to heat up the condensate to realize the low-temperature dust removal with high efficiency in the electrostatic precipitator(ESP) through reducing the fly ash specific resistivity at lower flue gas temperatures, to improve the boiler efficiency and to reduce the heat consumption and gross coal consumption for power generation units, a flue gas waste heat recovery device is designed and installed between the air pre-heater outlet and the ESP inlet in a 1 000-MW boiler. Practical operation shows that with the flue gas deep cooling device installed, the ESP dust removal efficiency is increased by 0.1% while the desulfurization water consumption is lowered substantially and the net coal consumption is significantly decreased.