300MW机组四角切圆煤粉炉空气与富氧燃烧对比模拟研究  

Comparative simulation of air and oxygen-enriched combustion in a 300MW tangentially fired pulverized coal boiler

作　　者：李宁 葛家楠 汪健生 LI Ning;GE Jianan;WANG Jiansheng(Hebei Special Equipment Supervision and Inspection Institute CangzhouBranch,Cangzhou 061000,China;Key Laboratory of Efficient Utilization of Low and Medium GradeEnergy,MOE,School of Mechanical Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]河北省特种设备监督检验研究院沧州分院,河北沧州061000 [2]天津大学机械工程学院(中低温热能高效利用教育部重点实验室),天津300072

出　　处：《热力发电》2022年第6期122-131,共10页Thermal Power Generation

摘　　要：富氧燃烧作为一种清洁能源技术可用于锅炉改造,从而降低污染物排放,回收CO_(2)。为研究空气气氛下和富氧环境中炉膛燃烧的不同,采用数值模拟方法研究了亚临界300 MW机组四角切圆煤粉炉炉膛内燃烧的传热特性。通过调整O_(2)体积分数、进入炉膛的烟气比率以及一次风和二次风量,可以得到和空气气氛下燃烧相近的火焰温度。研究了7种工况下的炉膛流场、温度场、O_(2)、CO_(2)、CO体积分数分布,以及它们在炉膛横截面平均体积分数随炉膛高度变化。模拟结果表明:不论是在富氧燃烧还是空气气氛下燃烧,炉膛内的流场分布相似,但是在同样的O_(2)体积分数下下,将N2替换为CO_(2)后会使炉膛内温度下降,火焰中心下移;增加O_(2)体积分数可以改善传热特性,增加煤粉燃烧的稳定性。As a clean energy technology,oxygen-enriched combustion can be used in boiler renovation to reduce pollutant emissions and recover CO_(2).To study the difference of furnace combustion between in air atmosphere and in oxygen-enriched environment,the heat transfer characteristics of combustion in furnace of a subcritical 300 MW tangentially fired pulverized coal furnace are studied by numerical simulation.By adjusting such parameters as the volume fraction of O_(2),the volume fraction of flue gas entering the furnace,and the volume of primary air and secondary air,the flame temperature in oxygen-enriched atmosphere that is similar to that in air atmosphere is obtained.The change rules of flow field,temperature field,volume fraction of O_(2),CO_(2) and CO in the furnace under seven conditions,as well as the mean volume fraction of O_(2),CO_(2) and CO in cross-section of the furnace with the furnace height were investigated.The simulation results reveal that,the flow fields in the furnace are similar in both air and oxygen-enriched combustion atmospheres.However,with the same volume fraction of oxygen,replacing N2 with CO_(2) will cause a decrease in the furnace temperature and make the flame center move down.Increasing the oxygen volume fraction can improve the heat transfer characteristics and make the pulverized coal combustion more stable.

关 键 词：切圆燃烧 O_(2)/CO_(2) 煤粉炉 富氧燃烧 数值模拟 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]