CAJ | 학술논문

由于循环流化床锅炉中二次风穿透深度不够而存在着炉膛中心供氧不足和流动不均匀的现象，这种气固流动的不均匀性不仅加重了水冷壁壁面磨损的问题，更使得燃烧效率大大降低，成为了制约循环流化床锅炉大型化发展的瓶颈。因此针对传统循环流化床锅炉二次风射流问题，本文对某150 MW循环流化床锅炉的二次风入口结构进行了改进设计，并采用欧拉双流体模型对改进前后炉内流场进行了数值模拟和对比分析。结果表明，入口改进后炉膛内部气固流场更加均匀，新的入口结构改善了中心区域“欠氧区”的存在，不仅提高了燃烧效率并可以减轻壁面的磨损程度，同时该结构下二次风以较小的动量即可达到穿透深度的要求，降低了风机的能耗，从而达到了节能的效果。
유우순배류화상과로중이차풍천투심도불구이존재착로당중심공양불족화류동불균균적현상，저충기고류동적불균균성불부가중료수랭벽벽면마손적문제，경사득연소효솔대대강저，성위료제약순배류화상과로대형화발전적병경。인차침대전통순배류화상과로이차풍사류문제，본문대모150 MW순배류화상과로적이차풍입구결구진행료개진설계，병채용구랍쌍류체모형대개진전후로내류장진행료수치모의화대비분석。결과표명，입구개진후로당내부기고류장경가균균，신적입구결구개선료중심구역“흠양구”적존재，불부제고료연소효솔병가이감경벽면적마손정도，동시해결구하이차풍이교소적동량즉가체도천투심도적요구，강저료풍궤적능모，종이체도료절능적효과。
The inadequate depth of secondary air caused boiler insufficient oxygen in the furnace center and uneven flow in the Circulating Fluidized Bed (CFB). The uneven flow between the gas and solid phases not only increased the abrasion on the cooling wall but also reduced the combustion efficiency, restricting the development of large-scale CFB boiler. Aiming at the injection of secondary air in CFB boiler,the design of secondary air inlet for a 150 MW CFB boiler was improved,using Eulerian multiphase model to investigate the flow field in the furnace. The results showed that the internal gas-solid flow field was more even with new inlet and anoxic zone in the center was eliminated, with a great improvement of combustion efficiency and reduction of the abrasion on the cooling wall. The improved design also allowed secondary air enter the furnace with lower momentum which reduced the energy consumption energy cost.