Low NOx Emission Technology for CFB Boilers
Product Features
High efficiency and low ammonia combustion technology are realized by optimizing the combustion structure in the furnace, reasonable material circulation control, air graded combustion and flue gas recirculation. It emphasizes the construction of ideal laminar fluidization of materials under the condition of reasonable low oxygen classification of secondary air and low primary air rate. Starting from four aspects of optimizing the fluidization of materials inside the furnace, improving the characteristics of ignition and burnout, ensuring or improving the thermal efficiency of the boiler, and optimizing the parameters of steam and air smoke, which includes four technologies:
The secondary air system transformation technology can realize the fractional combustion of air along the direction of the furnace cavity height and width, adjust the temperature field in the furnace so that there is no massive oxygen-rich high-temperature area and significant hypoxia area, and improve the uniformity of furnace temperature and the reasonable distribution of combustion share.
On the premise of ensuring fluidization efficiency, flue gas recirculation modification technology introduces tail low-oxygen flue gas 3 into the primary air system, reduces the oxygen content of primary air and dense phase area, and restrains the bed temperature, thus creating conditions for reasonable air classification.
Cyclone separator efficiency technology improves separation efficiency through inlet reshaping and center cylinder optimization, increases circulating ash amount to reduce bed temperature in dense phase area, increases furnace wall outlet temperature, improves boiler load capacity, and indirectly improves SNCR denitration efficiency.
Furnace bottom air distribution uniformity technology, specially optimized design of the air inlet mode of the furnace bottom air chamber, adjusts the resistance distribution of the hood in different air volume distribution areas, improves the air distribution uniformity, eliminates dust leakage in the air chamber, and solves the deviation of the operating bed material and the uneven bed temperature problem.
The technology has been widely used in nearly 60 boilers with a capacity of 75~1025T/h, among which 60% of slime stable blending is realized in Jisan Project of Yankuang, and more than 90% of high sodium coal is realized in Tunhe Project of Lanshan of Xinjiang.
