Spray system capable of concentrating desulfurization waste water by use of flue gas waste heat

Abstract

The invention discloses a spray system capable of concentrating desulfurization waste water by use of flue gas waste heat. The spray system comprises a flue heat exchanger, an evaporator set, a tail gas condenser, a tail gas condensation tank and a spray system body, wherein a desulfurization waste water pipeline and the flue heat exchanger are connected with the evaporator set, steam treated by the evaporator set sequentially enters the tail gas condenser and the tail gas condensation tank via pipelines, and a concentrated liquid treated by the evaporator set enters the spray system body through a pipeline; the flue heat exchanger heats the desulfurization waste water in the evaporator set by use of the flue gas waste heat; the evaporator set separates moisture and salt impurities in the desulfurization waste water in an evaporation manner; the evaporated steam is cooled to be condensed by the tail gas condenser; the tail gas condensation tank stores the condensed water and sends the condensed water into a finished product water tank; the spray system body atomizes the concentrated liquid and sprays the concentrated liquid in a boiler fuel gas exhaust channel. According to the system, no chemicals are added in the concentration process of the desulfurization waste water, clean water obtained after distillation is recycled, and the water recovery rate of a desulfurization waste water treatment system is higher than 90%.

Description

technical field [0001] The invention relates to the technical field of desulfurization wastewater treatment in thermal power plants, in particular to a spray system for concentrating desulfurization wastewater by using waste heat of flue gas. Background technique [0002] Limestone-gypsum desulfurization process (FGD) is the most widely used desulfurization technology in the world. About 90% of the flue gas desulfurization projects supporting coal-fired thermal power plants use this process. [0003] In the limestone-gypsum wet boiler flue gas desulfurization system of a large-scale thermal power plant, in order to ensure the desulfurization efficiency and maintain the balance of chloride ions in the system, part of the desulfurization wastewater needs to be discharged. Because the wastewater contains a large amount of dissolved salts, suspended solids, and a small amount of harmful pollutants such as fluoride ions and heavy metal ions, it cannot be discharged directly, and ...

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Problems solved by technology

[0005] (1) The amount of desulfurization wastewater is not large; however, the project occupies a relatively large area, and the process and equipment are complex

[0006] (2) The cost of engineering equipment and operating costs are high, which is difficult for power plants to accept

[0007] (3) Some ions with very little content, such as fluoride ions, are difficult to remove; they cannot meet the emission standards

[0008] (4) Scaling, corrosion and other problems often occur; affecting the safe operation of the system

[0009] (5) System maintenance is troublesome and complicated

[0010] (6) In addition to the reuse of treated water; the benefits of the power plant itself are small and the investment is huge

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