Method for reducing nitrogen oxide generated by combustion of boiler

Abstract

The invention discloses a method for reducing nitrogen oxide generated by combustion of a boiler. The method comprises the following steps of sucking one part of secondary air of the boiler as the rotary opposed over fire air comprising two parts; directly sending the first part to the upper space of a boiler hearth at the first speed, pressurizing the remained second part, and then sending the pressurized second part to the upper space of the boiler hearth at the second speed. The method for reducing the nitrogen oxide generated by the combustion of the boiler has the advantage that in the premise of ensuring the combustion efficiency of the boiler and the stable combustion state, the total emission amount of the harmful gas of the boiler, such as NOx, is greatly reduced.

Description

technical field [0001] The invention relates to a boiler combustion process, in particular to a boiler staged combustion process. Background technique [0002] With the promulgation of "Emission Standards of Air Pollutants for Thermal Power Plants" (GB13223-2011), my country's nitrogen oxides (NO x ) emission requirements become more stringent. Nitrogen oxides (NOx) produced during boiler combustion x ) is an air pollutant that is harmful to the environment and difficult to deal with, so reducing NO in boiler flue gas x content, thereby reducing NO x The emission of harmful gases is an important and difficult task. [0003] NO and NO generated during boiler combustion 2 Collectively referred to as NO x . According to NO x The formation mechanism of NO can be divided into thermal NO x , fuel type NO x and rapid NO x , where thermal NO x It is produced by a large amount of nitrogen in the air when the furnace temperature is higher than 1350°C during the combustion ...

AI Technical Summary

Problems solved by technology

In the actual use process, it is found that the low-oxygen combustion method can generally obtain a NOx emission reduction effect of about 20%, but it is easy to increase fly ash combustibles, reduce combustion efficiency, and cause side effects such as furnace coking; the pulverized coal concentration separation combustion method, generally It can achieve 20-45% NOx emission reduction effect, but it is easy to have a great impact on the combustion performance. When the pulverized coal is too thick, it is easy to cause the sintering of the burner, thus affecting the reliability of the boiler operation

The air staged combustion method is an effective and simple and feasible way to reduce NO x The technical method of emission can generally obtain 30-50% NOx emission reduction effect, but the existing staged combustion method will increase the carbon content of fly ash due to insufficient combustion, reduce the efficiency of the boiler and move the furnace flame up , consequences such as coking in the export area

Images