摘要
在二维热态可视化流化床实验平台上深入研究了O<sub>2</sub>/N<sub>2</sub>和O<sub>2</sub>/CO<sub>2</sub>气氛下单个煤颗粒燃烧特性。实验中流化床床温为1088 K,O<sub>2</sub>浓度为10%<sup>4</sup>0%,拟球形煤颗粒粒径为6 mm,两根热电偶分别记录煤燃烧过程中颗粒中心及表面温度的变化规律。实验结果表明:O<sub>2</sub>/CO<sub>2</sub>气氛下O<sub>2</sub>扩散速率低于O<sub>2</sub>/N<sub>2</sub>气氛,使得煤颗粒的平均表观燃烧速率、升温速率及温度峰值降低,燃尽时间延长;提高O<sub>2</sub>浓度后燃烧特性得以改善。为获得与空气气氛相近的燃尽时间,O<sub>2</sub>/CO<sub>2</sub>气氛下O<sub>2</sub>浓度约需25%,但O<sub>2</sub>浓度需30%才可达到和空气气氛相近的燃烧温度峰值。
Combustionof a single coal particle was stuided in a two-dimensional fmidized bed under O_2/N_2 and O_2/CO_2 atmospheres to evaluate the combustion behavior when replacing N_2 by CO_2.Experiments were performedat a fixed bed temperature of 1088 K with O_2 volume concentrations from 10%to 40%,coal particle diameter is 6 mm.Two thermocouples were inserted in the coal particle,to measure the temperature at the center and near the surface.Results indicate that the low O_2 diffusion rate in O_2/CO_2 decreases the average apparent burn rate increasing the burnout time and decreasing the combustion peak temperature.When O_2 concentration increases,the burn rate becomes increasing.In oxy-fuel atmosphere,the same burnout time and combustion peak temperaiter as in air are achieved at 25%and 30%O_2 concentration,respectively.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2015年第5期1143-1147,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.51276036
No.51306035)
江苏省普通高校研究生科研创新计划
东南大学优秀博士论文基金
关键词
富氧燃烧
流化床
煤颗粒
燃烧温度
燃尽时间
oxy-fuel combustion
fluidized bed
coal particle
combustion temperature
burnout time
