Efficient denitration system of W-flame boiler

Abstract

The invention belongs to the technical field of W-flame boiler denitration, and particularly relates to an efficient denitration system of a W-flame boiler. The efficient denitration system of the W-flame boiler is composed of a reducing agent storing and conveying unit, an SNCR blending measuring and mixing distribution unit, a multi-zone n-layer m-combination injection unit, an SCR removal unit, a TFC state detection unit and a data mining and full-automatic control unit; the data mining and full-automatic control unit calculates the denitration efficiency of an SCR denitration system according to the concentrations of NOx at an inlet and an outlet of the SCR denitration system, the numerical value of the denitration efficiency is compared with a set denitration efficiency value, when the numerical value of the denitration efficiency is lower than the set denitration efficiency value, the data mining and full-automatic control unit sends an instruction to the SNCR blending measuring and mixing distribution unit so as to increase the injection capacity of a reducing agent solution in an SNCR denitration system and decreasing the injection capacity of a reducing agent solution in the SCR denitration system simultaneously.

Description

technical field [0001] The invention belongs to the technical field of denitrification of a W flame boiler, and in particular relates to a high-efficiency denitrification system of a W flame boiler. Background technique [0002] With the combustion stability of anthracite, the W flame boiler better solves the problem of using low volatile coal to generate electricity. However, due to the low volatile content of the coal burned, it is difficult to ignite and burn out, there are many combustion zones in the furnace, the combustion temperature is high, and the NOx emission concentration is higher than that of ordinary pulverized coal furnaces, usually at 1300mg / Nm 3 Above, some even as high as 1800-2000mg / Nm 3 . At present, most pulverized coal boilers in power plants use selective catalytic reduction (SCR) technology for flue gas denitrification. The general SCR technology can achieve 90% denitrification efficiency, and it is difficult for the catalyst to maintain a high den...

AI Technical Summary

Problems solved by technology

When the boiler load changes, the change of flue gas volume will cause the change of the flow field. The traditional SNCR technology uses a spray gun with constant outlet pressure, which cannot be well matched with the flow field.

When the load increases, the injection pressure of the traditional spray gun is insufficient, causing the concentration of the reducing agent in the center of the furnace to be small; when the load decreases, the spray gun hedges again, causing the local concentration in the center of the furnace to be too high

The mixing degree of reducing agent and flue gas is not good, which reduces the denitrification efficiency on the one hand and increases ammonia slip on the other hand

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