Device for improving desulfurization efficiency of circulating fluidized bed boiler and method for improving desulfurization efficiency

Abstract

The invention relates to a device for improving desulfurization efficiency of a circulating fluidized bed boiler and a method for improving desulfurization efficiency. At present, an in-furnace desulfurization technology of the fluidized bed boiler adopts the method that lime stone is directly added from a material return valve, the interior of the lime stone cannot be in full contact with flue gas, the desulfurization reaction speed is relatively low, and improvement of the in-furnace desulfurization efficiency is limited. The device comprises a water feeding pipeline (1), wherein an inlet of the water feeding pipeline is connected with water feeding pumps (2); the water feeding pumps are connected with an inlet of a water storage tank (3) through the water feeding pipeline; an outlet of the water storage tank is connected with one ends of booster water pumps (5) through a water supply pipeline (4); the other ends of the booster water pumps are connected with flow adjusting valves (6); the flow adjusting valves are connected with a humidifying water spray gun (7) through the water supply pipeline; the humidifying water spray gun is mounted inside a material return leg (8); and the material return leg is mounted at the lower part of the fluidized bed boiler (9). The device is used for improving desulfurization efficiency of the circulating fluidized bed boiler.

Description

Technical field: [0001] The invention relates to a device and a method for improving the desulfurization efficiency of a circulating fluidized bed boiler. Background technique: [0002] At present, many desulfurization technologies in the fluidized bed boiler adopt the method of directly adding limestone from the return valve. [0003] The interior of the limestone cannot fully contact with the flue gas, and the desulfurization reaction speed is slow, which limits the improvement of the desulfurization efficiency in the furnace. The limestone is calcined in the return leg and the furnace to produce CaO for desulfurization reaction. Because it takes a long time for the limestone to be completely calcined, the fine-grained limestone is difficult to be captured by the cyclone separator, and it is easy to be directly discharged from the boiler together with the fly ash without reaction. Due to the limitation of the specific surface area of ​​the limestone, the interior of the l...

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Problems solved by technology

[0003] The interior of the limestone cannot fully contact with the flue gas, and the desulfurization reaction speed is slow, which limits the improvement of the desulfurization efficiency in the furnace

Limestone is calcined in the return leg and the furnace to produce CaO for desulfurization reaction. Because it takes a long time for the limestone to be completely calcined, the fine-grained limestone is difficult to be captured by the cyclone separator, and it is easy to be directly discharged out of the boiler together with fly ash without reaction. Due to the limitation of the specific surface area of ​​the limestone, the interior of the limestone cannot fully contact with the flue gas, and the desulfurization reaction speed is slow. The above reasons limit the further improvement of the desulfurization efficiency in the furnace, and also limit the utilization rate of the limestone. How to further improve the desulfurization in the furnace Efficiency, currently there is no effective technical means

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