Fluidized bed boiler denitration device and method based on cyclone separators

Abstract

The invention provides a fluidized bed boiler denitration device based on cyclone separators. The cyclone separators are connected to a hearth outlet flue of a fluidized bed boiler. Ammonia guns are arranged on outlet flues of the cyclone separators, and jet orifices of the ammonia guns of the outlet flues are downward. The invention further provides a fluidized bed boiler denitration method. According to the fluidized bed boiler denitration device provided by the invention, the flue gas temperature at the outlet flues of the cyclone separators is located between the optimum temperatures of denitration agent and NOx reaction; denitration reaction can be better conducted; the utilization rate of denitration agents is increased; a shut-off valve is installed on each newly-added pipeline to be matched with an original pipeline; and operation of the ammonia guns in the different positions can be switched at any moment under the different working conditions of the boiler, so that the optimum reaction combination is sought.

Description

technical field [0001] The invention belongs to the field of exhaust gas purification, and in particular relates to a denitration device and a denitration method for boiler flue gas. Background technique [0002] Selective non-catalytic reduction (abbreviated as SNCR) NOx removal technology is to spray the reducing agent containing NHx group (such as ammonia gas, ammonia water or urea, etc.) decomposed into NH 3 and other by-products, followed by NH 3 SNCR reaction with NOx in flue gas to generate N 2 . [0003] The advantages of SNCR denitrification include simple system, no need to change the equipment settings of the existing boiler, but only need to add ammonia or urea storage tank, ammonia or urea injection device and its injection port on the basis of the existing coal-fired boiler, The system investment is small, and the impact on the normal operation of the boiler is small; the system occupies a small area and other advantages. [0004] The main chemical reactio...

AI Technical Summary

Problems solved by technology

while NH 3 —In the SNCR system, the NOx reduction reaction is very sensitive to temperature conditions and residence time, which often leads to a low degree of chemical reaction and insufficient reaction, resulting in a low reduction rate of NOx, and the NH that did not participate in the reaction 3 Increase, excessive ammonia gas will overflow to form ammonium sulfate, which will easily cause blockage of air preheater and cause corrosion risk

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