What is low-NOx combustion technology?

The temperature and the amount of excess air in the combustion zone are decisive for the formation of NOx. Therefore, low NOx combustion technology is to control the temperature and air volume in the combustion zone to stop NOx generation and reduce its emission. At present, the commonly used low-NOx combustion technologies are as follows.

combustion optimization

a practical method to control NOx emissions by adjusting the combustion air distribution of the boiler. It takes measures to control NOx emissions by controlling the amount of combustion air, keeping the relative balance of the wind-powder (coal-powder) ratio of each burner and making combustion adjustments to minimize the generation of fuel-based NOx.

air classification combustion technology

is a more widely used low NOx combustion technology, its main principle is to carry out the fuel combustion process in sections. The technology is to divide the combustion air into primary and secondary air, reduce the amount of air in the pulverized coal combustion area (primary air), increase the concentration of pulverized coal in the combustion area, and delay the mixing time of primary and secondary air, so that a fuel-rich zone is formed when the pulverized coal enters the furnace, so that the fuel is burned in the fuel-rich zone without oxygen to reduce the generation of fuel-based NOx. The flue gas generated by anoxic combustion is then mixed with the secondary air to make the fuel burn completely.

The burners of large units put into operation in recent years, especially the supercritical and ultra-supercritical units basically adopt low-NOx combustion technology, which better control the NOx emission concentration.