An integrated system and method for dust-laden flue gas condensation heat energy recovery and flue gas purification

Abstract

The invention discloses a system and a method for integrally recycling condensation heat energy of flue gas with dust and purifying the flue gas, and belongs to the field of technologies for recycling heat energy of flue gas with dust and waste gas and deeply purifying the flue gas with the dust and the waste gas. The system comprises a chemical feeding high-position water tank, a dividing wall type heat exchanger, falling-film condensation absorbers and a settlement heat exchanger. A system flue gas inlet and a system external circulating water outlet are formed in the dividing wall type heat exchanger, and the dividing wall type heat exchanger is connected with the falling-film condensation absorbers by flue gas pipelines; the settlement heat exchanger is arranged below the falling-film condensation absorbers; water distributors are arranged on the upper portions of falling-film hole nets. The system and the method have the advantages that the system has integral functions of efficiently recycling waste heat of the flue gas with the dust and tail gas, removing the dust, desulfurizing and purifying the flue gas and the like, circulating water spraying components are not involved, external temperature control devices can be omitted, the flue gas and the tail gas can be directly regulated to be under the optimal wet desulfurization conditions, and efficient falling-film desulfurization can be carried out on the flue gas and the tail gas; the system can run reliably and is low in energy consumption, flue gas flow resistance and deep in desulfurization and low in dust removal cost, and the like.

Description

technical field [0001] The invention relates to an integrated system and method of dust-laden flue gas condensation heat energy recovery and flue gas purification, which belongs to the technical field of flue gas waste heat utilization and deep purification treatment, and can be used in coal-fired, oil-fired heating and power supply boilers and industrial boiler flue gas Heat energy recovery and purification of flue gas with complex components after dust removal by ordinary methods. Background technique [0002] At present, coal, fuel oil and some gaseous fuels usually contain a large amount of solid particles, SOx and NOx, water vapor, etc. in the flue gas of heating and power supply boilers and industrial boilers. Dust removal, there is still a small part of dust that has not been removed, and it needs to be further dusted. On the other hand, the exhaust gas temperature of this type of equipment is still high, about 120-150 ° C, and the content of water vapor in the flue ...

AI Technical Summary

Problems solved by technology

However, when the spray water absorbs heat, the problems of nozzle spraying failure and long-term corrosion due to the clogging of the nozzle due to the soot contained in the water and the condensation of the external soot near the nozzle are seldom considered. To solve this problem, the invention CN 201320198802 set up a flushing spray device, on the basis of the original spray design, regular descaling measures are added

The above-mentioned spraying or flushing spraying devices require large power consumption or the nozzles are prone to frequent blockage

[0005] In addition, CN102407070A provides a falling-film flue gas tail gas waste heat recovery device, which can effectively take into account gas purification, and is better for waste heat recovery and purification treatment of oil-fired gas boiler tail gas. There are still deficiencies in waste heat recovery and purification treatment of gas or exhaust gas. At this time, the water film wet absorption desulfurization process requires more desulfurization agents. At the same time, the partition wall heat exchanger is directly buried at the bottom of the sedimentation tank. In many cases, it is necessary to increase the height of the device to obtain the space required for precipitation and buffering. In addition, the method of direct falling film absorption of flue gas heat energy in this invention will partially evaporate water into the high-temperature and low-humidity flue gas tail gas, resulting in high-grade heat energy. Poor recycling effect

[0006] To sum up, the existing technology is limited to the existing technology combination of flue gas heat recovery and desulfurization and denitrification, but for the waste heat recovery of flue gas tail gas with large dust content, there is still a need for a high-efficiency waste heat recovery, flue gas A comprehensive treatment solution for deep purification, while taking into account the low power consumption performance of the system operation

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