热力发电2024，Vol.53Issue(1)：175-182,8.DOI:10.19666/j.rlfd.202305066
600 MW对冲燃烧锅炉分磨掺烧煤粉燃尽特性的模拟和试验研究
Simulation and experimental study on the burnout characteristics of pulverized coal in a 600 MW opposed combustion boiler by mixing grinding and burning
摘要
Abstract
In order to explore the effects of mixed coal combustion on reducing the carbon content of fly ash in a subcritical 600 MW natural circulation balanced draft boiler,three types of coal with significant differences in characteristics were used,and numerical simulations were combined with experiments to study the mechanism of mixed coal combustion and its relationship with fuel characteristics,burnout rate,and carbon content in fly ash in the stratified combustion process of the balance boiler.Based on the results,a set of coal blending principles are proposed to improve the combustion characteristics of coal powder in power station boilers.Firstly,three extreme operating conditions were set up,and high-quality coal was respectively focused on the upper,middle,and lower layers of the burner for combustion.And then,through computational fluid dynamics(CFD)simulations,it was found that when the coal powder airflow of the balance combustion boiler flowed upward,and the high-quality coal was distributed in the upper layer of the combustion chamber while the poor-quality coal was distributed in the lower layer,the residence time of poor-quality coal in the furnace increased significantly,allowing it to fully combust in the high-temperature area of the upper layer,resulting in a low carbon content in fly ash.Furthermore,based on the analysis of the heat value,volatile matter and ash content of coal powder in different combustion layers under various working conditions,it was found that the difference in heat value and ash content is the main factor influencing combustion characteristics.Based on the actual operating conditions of the coal-fired power plant,a more realistic set of coal blending scenarios was established,and numerical simulations and on-site experiments were conducted,which showed that the overall combustion characteristics of coal powder under each working condition followed the aforementioned rules,and the carbon content in the fly ash reduced compared with the original operating conditions.Finally,the coal blending principles were established,which take into full consideration of the actual operating conditions of the power plant,recommend high-quality coal with low ash content to be used in the upper and middle layers of the combustion chamber while poor-quality coal with high ash content should be used in the middle and lower layers of combustion burner.关键词
燃煤锅炉/配煤掺烧/煤质/燃尽率/飞灰含碳量Key words
coal-fired boiler/coal blending/coal quality/burnout rate/carbon content of fly ash引用本文复制引用
彭昭雄,刘兵兵,范多文,刘磊,刘小伟..600 MW对冲燃烧锅炉分磨掺烧煤粉燃尽特性的模拟和试验研究[J].热力发电,2024,53(1):175-182,8.基金项目
国家基金委联合基金重点项目(U22A20211)Key Project of the Joint Fund of the National Foundation of China(U22A20211) （U22A20211）
