炼钢转炉低质煤气在旋风分离器中的高效燃烧特性  

Efficient combustion characteristics of converter low-quality gas from steelmaking in cyclone separator

作　　者：王梓熠 李森[1,2] 魏小林 赵京[1] 李博 姚远[1] WANG Ziyi;LI Sen;WEI Xiaolin;ZHAO Jing;LI Bo;YAO Yuan(State Key Laboratory of High Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院力学研究所高温气体动力学国家重点实验室,北京100190 [2]中国科学院大学工程科学学院,北京100049

出　　处：《洁净煤技术》2024年第11期13-23,共11页Clean Coal Technology

基　　金：中国科学院战略性先导A类基金资助项目(XDA29020503)。

摘　　要：转炉低质煤气CO浓度低且含有少量O_(2),存在爆炸危险,无法回收利用,目前通过卷吸空气使转炉低质煤气在气化冷却烟道内无组织地燃烧,现有技术难以实现气化冷却装置内煤气的高效燃烧利用。旋风分离器内部流场拥有强旋流、强混合的特点,实现转炉煤气除尘的同时有利于转炉低质煤气的混合燃烧。为解决转炉低质煤气难以高效燃烧利用的难题,基于转炉煤气全干法回收新工艺,采用数值模拟的方法研究了转炉低质煤气在旋风分离器内部的流动和燃烧情况。结果表明:气化冷却烟道中心附近过量空气系数均低于0.4,而旋风分离器内过量空气系数均大于1,转炉低质煤气与空气在旋风分离器内得到了充分混合;较高的湍流动能、局部旋涡提升了转炉低质煤气与空气在旋风分离器内的混合效果;气化冷却烟道内燃烧区域狭小,流动截面内OH平均体积分数为305×10^(-6),燃烧强度低;旋风分离器内燃烧区域分布广泛,流动截面内OH平均体积分数达到650×10^(-6),燃烧强度高;转炉低质煤气流经旋风分离器后,在前烧阶段燃烧效率从74.64%上升到98.86%,在后烧阶段燃烧效率从44.08%上升到95.05%;在旋风分离器内部实现了转炉低质煤气的高效燃烧。At the beginning and end of oxygen blowing in converter steelmaking,the converter gas produced is of low quality(low CO concentration with a small amount of O_(2)),which is explosive and cannot be recycled.At present,the converter low-quality gas is burned unorganized in the gasification cooling stack by entraining air,which is difficult to realize the efficient combustion and utilization of the gas in the gasification cooling device.The characteristics of strong swirl and strong mixing in the cyclone separator are conducive to the mixed combustion of converter low-quality gas while removing dust from converter gas.In order to solve the difficulty in efficient combustion and utilization of converter low-quality gas,based on a new process of converter gas full dry recovery,the flow and combustion of converter low-quality gas in the cyclone separator were studied by CFD.The results show that:the excess air coefficients near the center of gasification cooling stack are lower than 0.4,all the excess air coefficients in the cyclone separator are higher than 1,the converter low-quality gas is fully mixed with air in the cyclone separator;The higher turbulent kinetic energy and local vortex improve the mixing of converter low-quality gas and air in the cyclone separator;The combustion area in the gasification cooling stack is narrow,the average concentration fraction of OH in the flow section is 305×10^(-6),and the combustion intensity is low;The combustion area in the cyclone separator is widely distributed,the average concentration fraction of OH in the flow section reaches 650×10^(-6),and the combustion intensity is high;After the converter low-quality gas flows through the cyclone separator,the combustion efficiency increases from 74.64%to 98.86%in the pre combustion stage,and the combustion efficiency increases from 44.08%to 95.05%in the post combustion stage;The efficient combustion of converter low-quality gas is realized in the cyclone separator.

关 键 词：转炉低质煤气 气化冷却烟道 高效燃烧 旋风分离器 混合燃烧 燃烧效率 

分 类 号：TF71[冶金工程—钢铁冶金]