Desulfurized flue gas dehumidification and water recovery system and method

Abstract

The invention discloses a desulfurized flue gas dehumidification and water recovery system and method. The system comprises a dehumidifier, a heat exchanger, a flash evaporator and a steam compressor. A moisture absorption solution in the dehumidifier makes contact with desulfurized flue gas, water in the desulfurized flue gas is removed, and a dilute solution is obtained; the dilute solution flowing out of the dehumidifier enters the heat exchanger for heat exchange, and a high-temperature dilute solution is obtained; the high-temperature dilute solution flowing out of the heat exchanger enters the flash evaporator for flash evaporation, a regenerated moisture absorption solution and low-pressure steam are obtained, the moisture absorption solution enters the dehumidifier, the desulfurized flue gas is dehumidified, the low-pressure steam is compressed through the steam compressor and then enters the heat exchanger, and the dilute solution is heated. After the steam generated in the flash evaporation process is compressed to increase the boiling point, a heating heat source used as the dilute solution is condensed and subjected to heat release, heat needed by regeneration of the dilute solution does not need to be supplied by the exterior, and the energy consumption and operating cost of the desulfurized flue gas solution dehumidification system are reduced to the maximum degree.

Description

technical field [0001] The invention relates to the field of boiler flue gas treatment, in particular to a desulphurization flue gas dehumidification and water recovery system and method. Background technique [0002] Power, metallurgy, iron and steel, and chemical processes usually produce a large amount of moisture-containing gas. The volume content of water vapor in the flue gas discharged from gas-fired boilers can reach about 15%. The volume composition of steam can also reach more than 10% of the total amount of flue gas. These humid gases are basically in a saturated state. When they are directly discharged at the outlet of the chimney, the water vapor will condense into water droplets, thus forming "chimney rain" and "white smoke". And other environmental problems, and the formation of acid inside the chimney to cause corrosion. In addition, the direct discharge of wet gas also causes a waste of water resources. [0003] At present, the solutions to the "chimney ra...

AI Technical Summary

Problems solved by technology

Conventional solution regeneration consumes the heat provided by the outside to evaporate and discharge the water in the dilute solution. The concentration of the solution increases, and the heat provided by the outside is converted into latent heat of water vapor. Due to the heat transfer process, the boiling point of water vapor is lower than the temperature of the heat source required for regeneration, so The latent heat of water vapor cannot be recovered for heating the dilute solution, thus affecting the thermal efficiency of the entire boiler system and increasing the operating cost

On the other hand, although solution dehumidification can extract part of the water from the exhaust gas, the recovery of this part of water needs to be realized by condensing the water vapor generated in the regeneration process of the dehumidification solution. Cooling water, heating return water, etc.) to take away the latent heat of condensation of water vapor, which makes the solution dehumidification system complicated, and the water recovery effect is also limited by the temperature and flow of the cold source

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