Comprehensive utilization method of thermal power plant boiler wastewater

Abstract

The invention provides a comprehensive utilization method of thermal power plant boiler wastewater. The comprehensive utilization method comprises the following process steps: (1) continuous boiler wastewater goes into a continuous blowdown flash tank for reduced-pressure flashing; secondary steam generated after flashing is guided out of the upper part of the continuous blowdown flash tank and into a deaerator; (2) the hot wastewater at the bottom of the continuous blowdown flash tank is guided into a boiler periodic blowdown flash tank for further reduced-pressure flashing together with regular boiler wastewater; (3) the secondary steam generated by flashing from the periodic blowdown flash tank serves as a heat source and is guided into a low-temperature multiple-effect evaporator group, and bottom salt-containing wastewater also goes into the low-temperature multiple-effect evaporator group as the evaporated liquid; (4) the condensed water generated by the low-temperature multiple-effect evaporator group and the steam condensed water out of a cooler are collected to a condensed water tank by use of a condensation header and then fed into a boiler water supply system by use of a condensed water pump to be recycled; a thickened liquid generated by performing multiple-effect evaporation on the salt-containing wastewater is recycled into a thickened liquid recovery tank and then fed into a wet boiler flue gas desulphurization system used as a desulfurizing agent for desulphurization.

Description

technical field [0001] The invention relates to a method for comprehensive utilization of boiler sewage in a thermal power plant. Background technique [0002] Boiler blowdown in thermal power plants is divided into two forms: continuous blowdown and regular blowdown. The blowdown rate is generally between 1% and 2%. The continuous blowdown is drawn from below the liquid surface close to the water level line of the boiler drum, the purpose is to continuously discharge the boiler water with a large salt content, maintain the salt content of the boiler water, and stabilize the quality of the boiler water; the regular blowdown is usually drawn from the bottom of the heating surface, and the thermal power plant boiler Most of them are drawn from the lower header of the boiler water wall, and the purpose is to regularly release solids such as sediment and rust at the bottom of the boiler water. The temperature of boiler sewage hot water is about 100°C, generally alkaline, and th...

AI Technical Summary

Problems solved by technology

This traditional sewage and hot water treatment scheme not only wastes the heat contained in the sewage and hot water, but also needs to be mixed with cold water when it is discharged from the trench, which wastes water resources and pollutes the environment.

Images