A heat recovery water-saving system for wet desulfurization and its process

Abstract

The invention relates to a heat recovery water-saving system for desulfuration by a wet process and a process method thereof. The process method comprises the following steps: carrying out heat exchange on waste heat of slurry of an absorption tower in a conventional wet gas desulphurization device through an external heat exchanger, wherein the temperature of the slurry in the tower is reduced; pumping the slurry in the tower at lower temperature to a spraying layer through a circulating pump; and continuously carrying out gas-liquid contact in the desulphurization process. The lower temperature of the desulphurization slurry is beneficial for improving the desulphurization efficiency and reducing the liquid-gas ratio in the desulphurization process; the temperature of the desulphurization smoke is reduced from about 130 DEG C to about 40 DEG C similarly, smoke heat is conducted to circular slurry and recovered by the external heat exchanger, and the evaporated water in the smoke temperature reducing process is reduced, so that the water consumption in a wet desulphurization system is reduced; and the purposes of saving energy consumption and water consumption for users as well as lowering the operational cost are realized. Meanwhile, through heat transfer temperature rise of the external heat exchanger, the cooling circular water is about 27 DEG C, and hot water at higher temperature or low pressure steam over 120 DEG C through hot pump treatment is provided for users.

Description

technical field [0001] The invention relates to the technical field of wet desulfurization, in particular to a heat recovery and water-saving system and a process thereof in a wet desulfurization project. Background technique [0002] With the promulgation of new air pollutant emission standards for thermal power plants, the emission standards for sulfur dioxide in flue gas have been further improved, and coupled with the tight supply of coal for domestic power plants, the coal quality components actually used by many power plants deviate greatly from the original design values, resulting in The concentration of sulfur dioxide at the inlet of the desulfurization device far exceeds the original design value, and the original desulfurization device can no longer meet the requirements of environmental protection. In order to ensure the safe and stable operation of the desulfurization system and meet the requirements of standard discharge under new coal quality conditions, the or...

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Problems solved by technology

[0002] With the promulgation of new air pollutant emission standards for thermal power plants, the emission standards for sulfur dioxide in flue gas have been further improved, and coupled with the tight supply of coal for domestic power plants, the coal quality components actually used by many power plants deviate greatly from the original design values, resulting in The concentration of sulfur dioxide at the inlet of the desulfurization device far exceeds the original design value, and the original desulfurization device can no longer meet the requirements of environmental protection. In order to ensure the safe and stable operation of the desulfurization system and meet the requirements of standard discharge under the new coal quality conditions, the original The capacity of the desulfurization device is increased, and various measures are taken to improve the desulfurization efficiency. At present, a heat exchanger is installed in front of the entrance of the absorption tower to reduce the temperature of the original flue gas and achieve the purpose of improving efficiency.

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