摘要
作为钢铁行业碳减排的重要环节,石灰窑生产工序以空气助燃为主,尾气中CO_(2)浓度偏低,难以实现低成本碳捕集。富氧燃烧是一种有效的碳富集技术,但是采用该技术时石灰窑内高体积分数CO_(2)气体辐射会影响窑内温度分布及碳酸钙的分解特性。为此,本文以双膛石灰窑为研究对象,建立石灰窑生产过程的数值仿真模型,研究富氧燃烧下气体辐射对石灰石煅烧特性的影响,并比较不同O_(2)/CO_(2)配比下窑内的温度、组分及碳酸钙质量分数变化。结果表明:考虑气体辐射后,石灰窑内CO_(2)组分浓度没有明显改变,但窑内最高温度降低约60~100 K,同时最高气相温度随着O_(2)体积分数的增大而升高;考虑气体辐射后,石灰窑内煅烧区气相及碳酸钙的平均温度升高,窑内碳酸钙的分解速率加快,其气相平均温度升高约30~90 K,碳酸钙平均温度升高约30~130 K,且随着O_(2)体积分数的增大而升高,窑内碳酸钙的分解速率也随O_(2)体积分数的增大而加快。本文研究成果可为石灰窑内温度及碳酸钙分解特性的准确模拟提供理论支撑,同时也为富氧燃烧技术在双膛石灰窑内的应用提供参考。
As an important link in carbon emission reduction in the steel industry,the production process of lime kiln is mainly air-fueled combustion,and the CO_(2) concentration in the exhaust gas is low,making it difficult to achieve low-cost carbon capture.Oxygen-enriched combustion is an effective carbon enrichment technology,but the high volume fraction CO_(2) gas radiation in the lime kiln will affect the temperature distribution and decomposition characteristics of calcium carbonate in the kiln.Therefore,the double-chamber lime kiln is taken as the research object to establish a numerical simulation model of the lime kiln production process,study the effect of gas radiation on the calcination characteristics of limestone under oxygen-rich combustion,and compare the changes of temperature,composition and calcium carbonate content in the kiln under different O_(2)/CO_(2) ratios.The results show that the CO_(2) component concentration in the lime kiln does not change significantly after considering the gas radiation,but the maximum temperature in the kiln decreases by about 60~100 K,and the maximum gas phase temperature increases with the increase of O_(2) volume fraction.After considering the gas radiation,the average temperature of the gas phase and calcium carbonate in the calcination area in the lime kiln is increased,and the decomposition rate of calcium carbonate in the kiln is increased,and the average temperature of the gas phase is increased by about 30~90 K,and the average temperature of calcium carbonate is increased by about 30~130 K increasing with the increase of O_(2) volume fraction,and the decomposition rate of calcium carbonate in the kiln also is accelerated with the increase of O_(2) volume fraction.The results can provide theoretical support for the accurate simulation of temperature and calcium carbonate decomposition characteristics in lime kilns,and also provide a reference for the application of oxygen-rich combustion technology in double-chamber lime kilns.
作者
李宏鹏
周浩宇
朱蓉甲
伍东玲
王志奇
杨胡娅
LI Hongpeng;ZHOU Haoyu;ZHU Rongjia;WU Dongling;WANG Zhiqi;YANG Huya(School of Mechanical Engineering and Mechanics,Xiangtan University,Xiangtan 411105,Hunan,China;Zhongye Changtian International Engineering Co.,Ltd.,Changsha 410205,Hunan,China;School of Energy Science and Engineering,Central South University,Changsha 410083,Hunan,China)
出处
《烧结球团》
2025年第6期101-109,共9页
Sintering and Pelletizing
基金
湖南省自然科学基金资助项目(2024JJ7544)
中冶长天科研开发基础研究基金资助项目(2023JCY106)。
关键词
双膛石灰窑
富氧燃烧
气相辐射
数值模拟
double-chamber lime kiln
oxygen-rich combustion
gas-phase radiation
numerical simulation
