Method for controlling considerable coal-fired boiler NOx discharge by multilevel reduction wind

Abstract

The invention relates to a method used for controlling the exhaust of NOx out of a high-capacity coal burning boiler by a multi-level reduction wind in the environmental protection technical field. A plurality of layers of series reduction wind air spouts are arranged along the stroke in a reduction area between a main burner area at the lower part of a furnace hearth and a burn-out wind spout arranged at the upper part of the furnace hearth. The air which is sprayed out of the series spouts is equal to 13%-20% of the total air quantity which is required by the combustion of the boiler coal-fired quantity and is divided into two parts: one part is used for controlling the oxygen consistency of the flue gas in the reduction area so as to reduce the exhaust of nitrogen oxides and the spouts in this part are called control spouts, while the other part is used for protecting the water cooled wall in the reduction area and the spouts in this part is called protection spouts; the slagging and high temperature corrosion are avoided by the oxidation ambience around the water cooled wall. The method used for controlling the exhaust of NOx out of a large-capacity coal-fired boiler by a multi-step reduction wind has the advantages of further enlarging the air classification degree, reducing the exhaust of the nitrogen oxides to a greater extent, protecting the water cooled wall in the reduction area against slagging or high temperature corrosion, reducing the increase of ash carbon-containing quantity caused by the classification, etc.

Description

technical field [0001] The invention relates to a NOx emission method in the technical field of boilers, in particular to a method for controlling NOx emission of a large-capacity coal-fired boiler with multi-stage reducing air. Background technique [0002] Nitrogen oxides (NOx, including NO, NO 2 , N 2 O) is a class of gases that can cause serious air pollution and is considered to be one of the main sources of air pollution. Nitrogen oxides from the burning of fossil fuels account for a large proportion of all nitrogen oxide emissions worldwide each year. The increasingly stringent environmental regulations require the research and development of advanced combustion technologies to reduce emissions of pollutants such as NOx. At present, the most important feature of my country's energy composition is coal, accounting for more than 70%, which will produce a large amount of nitrogen oxide gas. Therefore, such an energy structure will have a negative impact on economic an...

AI Technical Summary

Problems solved by technology

These negative problems in the furnace caused by insufficient technology will seriously affect the economical and safe operation of the boiler

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