Zero discharging treatment system for heat-engine-plant tail-end high-salinity wastewater and working method thereof

Abstract

The invention relates to a zero discharging treatment system for heat-engine-plant tail-end high-salinity wastewater and a working method thereof. The zero discharging treatment system is used for zero discharging of the large-power-station tail-end high-salinity wastewater. The zero discharging treatment system comprises a low-temperature smoke pipe, a high-temperature smoke pipe, an air preheater, a smoke cooler, a dust collector, a desulfurizing tower and an induced draft fan; a vacuum pump pumps steam in a low-temperature evaporator to form a vacuum, the high-salinity wastewater entering the tail end of the low-temperature evaporator absorbs heat fed by a smoke heat exchanger at this moment, and is evaporated and concentrated under the low temperature and low pressure condition, generated steam is subjected to steam-water separation, separated gas enters a desulfurizing tower, and separated water becomes supplementing water of a gas desulfurization system to keep a water balance; the concentrated wastewater is sprayed into an inlet flue or an outlet flue of the air preheater and is flashed, and the zero discharging aim of the tail-end high-salinity wastewater is finally achieved. By means of the zero discharging treatment system for the heat-engine-plant tail-end high-salinity wastewater and the working method thereof, zero discharging of the whole-heat-engine-plant tail-end high-salinity wastewater can be achieved, the inlet smoke temperature of the air preheater and the boiler efficiency cannot be influenced, and the blocking risk of the air preheater is avoided.

Description

technical field [0001] The invention relates to a zero-discharge treatment system for high-salt wastewater at the end of a thermal power plant and a working method thereof, which are used for zero-discharge treatment of high-salt wastewater at the end of a thermal power plant. Background technique [0002] my country's national conditions are still dominated by thermal power generation, and thermal power plants have sewage from circulating water, desulfurization wastewater from limestone-gypsum wet desulfurization systems, reverse osmosis sewage, etc. These sewage contain many toxic and harmful substances. Treatment is required to meet discharge requirements. Due to the wide variety of wastewater quality and different water volumes, it is difficult to treat these wastewaters, and these methods generally have problems such as complex systems, large footprints, and high operating costs. [0003] The current terminal high-salt wastewater treatment technologies mainly include th...

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Problems solved by technology

Although this method also achieves zero discharge of wastewater, the concentrated wastewater of this system uses the flue gas before the inlet of the air preheater to evaporate, which will eventually reduce the boiler efficiency and increase the risk of blockage of the air preheater. Limited by the temperature of the low-temperature flue gas, when the temperature of the low-temperature flue gas is lower than 100°C, it will be difficult to concentrate the desulfurization wastewater

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