Boiler optimization method for reducing nitrogen oxide discharge

Abstract

The invention discloses a boiler optimization method for reducing nitrogen oxide discharge. A boiler is a 600MW machine set boiler, and a hearth of the boiler is sequentially divided into an AA layer, an A layer, an AB layer, a B layer, a BC layer, a C layer, a CD layer, a D layer, a DE layer, an E layer, an EF layer, an E layer, an FF layer and an OFA layer from bottom to top. The method comprises the following steps that the opening degree of a secondary air baffle plate of the AA layer of the boiler is set to -40 percent bias switching automation, the opening degree of a secondary air baffle plate of the AB layer of the boiler is set to -10 percent bias switching automation, the opening degree of a secondary air baffle plate of the BC layer of the boiler is set to -23-30 percent bias switching automation, the opening degree of secondary air baffle plates of the CD layer and the DE layer of the boiler is set to unbiassed switching automation, the opening degree of secondary air baffle plates of the EF layer, the FF layer and the OFA layer of the boiler is set to +15 percent bias switching automation, the opening degree of a secondary air baffle plate of the boiler is set to +15 percent bias switching automation, and the opening degree of a circumferential air baffle plate of the boiler is set to 70 percent when the rotation speed of a coal feeding machine of the boiler is higher than 80 percent of the rated rotating speed. The method realizes the low NOx (nitrogen oxide) discharge.

Description

technical field [0001] The invention relates to the field of boilers, in particular to a boiler optimization method for reducing nitrogen oxide emissions. Background technique [0002] The 600MW unit boiler produced by Shanghai Boiler Factory was imported from CE Company of the United States in the 1970s. Boiler design NO x The emission is 350mg / Nm 3 , because the process quality of design, manufacture, and installation in my country cannot meet the requirements, in fact, when the boiler is running under the rated load, NO x Emissions are 600~650mg / Nm 3 . [0003] By analyzing the boiler combustion process NO x Generating rationale: NO produced in the boiler x Mainly divided into thermal NO x and fuel NO x , however, experiments have shown that the NO produced by the inherent N in the fuel x Only 10%, 90% of the NO x Reduction to N under the action of oxygen 2 , so, during normal operation, boiler combustion forms NO x Mainly thermal NO x , that is sent into t...

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Problems solved by technology

[0004] According to the formation of NO x The basic principle is that as long as the oxygen content in the high temperature combustion area is reduced, NO can be controlled x However, if the oxygen content of the furnace in the high-temperature combustion area is reduced, the reducing gas H will easily appear in this area 2 S and CO, forming reducing gas, easily aggravate boiler coking and high temperature sulfur corrosion

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