NOx includes thermal type NOx, fast type NOx, and fuel type NOx. Thermal NOx is mainly generated by the high temperature (above 1500 ℃) generated by fuel combustion, which oxidizes N in the air to NOx. Its emissions are affected by combustion temperature, oxygen concentration, and residence time. Fast NOx is generated when the hydrocarbon fuel in the mixture is too rich. Generally, it is only considered when the nitrogen free hydrocarbon fuel is burned at low temperatures. Fuel type NOx mainly refers to the oxidation of N in the fuel to generate NOx during the combustion process. Its generation is mainly related to the atmosphere and environment of fuel combustion. When the combustion temperature of the fuel is about 700 ℃, fuel type NOx will be generated. For gas fired boilers, fuel type NOx is significantly lower than thermal type NOx.

Due to the influence of combustion temperature, oxygen concentration, and residence time on the emission of thermal NOx, when the combustion temperature is below 1500 ℃, the generation of NOx is almost impossible to monitor, and when the combustion temperature is above 1500 ℃, the generation rate of NOx increases exponentially; The higher the oxygen concentration, the higher the combustion temperature, and the greater the amount of NOx generated; The longer the combustion time, the greater the amount of NOx generated.

The low nitrogen combustor developed by our company adopts staged combustion and dense lean combustion technology: the combustion air enters from the combustion air inlet of the low nitrogen combustor, and different combustion air channels are provided at the burner nozzle. For low calorific value blue carbon tail gas, this type of low nitrogen combustor is provided with central combustion air (first graded air), dense combustion swirl air (second graded air), and thin combustion swirl air (third graded air) regions, It is mixed with the corresponding third stage gas region to achieve rich lean and staged combustion, achieving the goal of balancing the furnace temperature field and reducing thermal nitrogen oxides.

The low nitrogen burner is based on the axial airflow dynamic characteristics and the principle of fuel staged replenishment, utilizing the combined effect of vortex and non streamline bodies to achieve uniform distribution of fuel and combustion supporting air, while achieving super mixing of fuel and air, thereby achieving uniform flame temperature and reducing the generation of thermal NOx. In addition to the burner body and nozzle, the system also includes a gas pipeline section, a combustion air section, and a control section.