燃油锅炉油雾燃烧过程中碳烟的排放特性

Emission Characteristics of Soot Particles from Combustion of Fuel Mist in a Fuel Oil Boiler

针对2t/h卧式锅壳锅炉炉膛结构及换热特点，建立了炉膛换热条件下油雾燃烧的非预混燃烧模型，研究了风速对炉内燃料燃烧及碳烟颗粒物排放特性的影响．结果表明，炉内燃料浓度在炉膛轴向0．3—0．7m的范围内快速降低，碳烟颗粒物主要在距炉膛燃料喷口0．3—1．5m的混合燃烧区内迅速生成，并随风速增大而远离喷口，生成速率在着火点位置最大．风速过大或过小都会增加碳烟颗粒物的生成，风速7．5m／s时炉膛碳烟排放浓度最小，出口浓度分布更均匀，约为0．042％（ω）．

A non-premixed combustion model was established based on the chamber structure and heat transfer characteristics of a 2 t/h horizontal shell oil-fired boiler, and the effect of wind speed on the mist combustion and emission characteristics of soot particles analyzed. The results showed that the fuel concentration in the chamber rapidly reduced along the axial direction in 0.3～0.7 m from the fuel nozzle. The soot particles were quickly generated in the mixed combustion zone from the fuel nozzle of 0.3-1.5 m, and went away from the nozzle with increasing of wind speed. The largest generation rate appeared at the ignition point. When the wind speed was too big or too small, the generated soot particles increased. When the wind speed was 7.5 m/s, the soot concentration was the smallest and most evenly, and its value was 0.042%（ω）.