Device and system for white smoke elimination, emission reduction and deep waste heat recovery for coal-fired flue gas

Abstract

The invention provides a device and a system for white smoke elimination, emission reduction and deep waste heat recovery for coal-fired flue gas, and relates to the energy field. The device comprisesa flue gas desulfurization unit, a flue gas waste heat recovery unit, a flue gas-air total heat exchange unit and a flue gas white smoke elimination unit. Through the arrangement for the flue gas-airtotal heat exchange unit, flue gas waste heat is recovered, and the moisture content of combustion-supporting air is increased, so that the dew point temperature of the flue gas is increased; throughthe arrangement for the flue gas waste heat recovery unit and the flue gas white smoke elimination unit, vapor in the flue gas is condensed and recovered, and finally the moisture content of flue gasemission is lowered, and the generation of white smoke is reduced; the humidification degree of air is increased, a combustion temperature can be lowered, and the emission of NOx and SO2 is reduced;the technical problems that lots of flue gas waste heat is wasted and the phenomenon of white smoke is generated, in the prior art, are alleviated; and a natural cold source of outdoor air in winter is utilized as a main cooling and dehumidification source, mutual coupling in mechanism and mutual supplement are achieved, and the effect of integrating the functions of desulfurization, nitrogen reduction, waste heat recovery, white smoke elimination and the like is realized.

Description

technical field [0001] The invention relates to the field of energy technology, and is particularly suitable for boiler flue gas waste heat recovery and reduction of sulfide and nitrogen oxide emissions, and in particular to a coal-fired flue gas whitening, emission reduction and waste heat deep recovery device and system. Background technique [0002] Coal contains hydrogen and water, and boiler combustion produces a large amount of water vapor. This part of the latent heat of water vapor is often discharged directly into the atmosphere along with the flue gas, resulting in waste of waste heat from the flue gas. The waste heat of the flue gas accounts for about 10% of the low-level calorific value of coal. . Therefore, if the temperature of the flue gas can be lowered below the dew point and the recovery of this part of latent heat plays an important role in saving fuel consumption. On the other hand, the flue gas produced by boiler combustion contains a large amount of su...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a coal-fired flue gas whitening, emission reduction and waste heat deep recovery device and system, so as to alleviate the technical problems in the prior art that a large amount of flue gas waste heat is wasted and the phenomenon of "white smoke" is generated

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