单个焦炭颗粒在燃烧环境中的曳力研究  

Drag Force on Single Char Particle Under Combustion Conditions

作　　者：屈思博 张纬 由长福[1,2] Qu Sibo;Zhang Wei;You Changfu(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Department of Energy and Power Engineering,Tsinghua University,Beijing100084,China;Shanxi Research Institute for Clean Energy,Tsinghua University,Taiyuan 030000,China)

机构地区：[1]清华大学能源与动力工程系热科学与动力工程教育部重点实验室,北京100084 [2]清华大学山西清洁能源研究院,太原030000

出　　处：《燃烧科学与技术》2022年第6期701-707,共7页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51761125012);华能集团总部科技项目——基础能源科技研究专项资助项目(HNKJ20-H50).

摘　　要：为明确单个焦炭颗粒在非燃烧与燃烧状态下的曳力变化,采用虚拟区域方法对半径为100~500μm的固定焦炭颗粒分别在303 K(非燃烧)与1173K(燃烧)温度下的受力及其流场进行数值模拟.结果显示,同样在悬浮状态下,受高温环境下物性变化与化学反应的影响,燃烧的焦炭颗粒的雷诺数更小,生成的流场更稳定.燃烧的焦炭颗粒所受黏性力比非燃烧的大,所受压力比非燃烧的小,且其差值随着气体速度与粒径增大而增大.因此,较大尺寸的燃烧焦炭颗粒的终端速度比非燃烧的更大,对应的曳力系数更小.To clarify the difference of drag force on single char particle under non-combustion and combustion conditions,the force and flow field were obtained from the numerical simulation of fixed char particle(radius:100-500 μm)in a gas flow under 303 K(non-combustion)and 1 173 K(combustion),respectively,by fictitious domain method. Results show that in the same floating state,the burning char particle yields smaller Reynolds number and more stable flow field due to the changes in physical properties and the chemical reactions in the environment of high temperature. Compared with the cold char particle,the viscous force on the burning particle is greater,and the pressure is smaller. The difference is more significant with the increase of gas velocity and particle size. Therefore,the terminal velocity of larger burning char particle is greater than that of cold char particle,while the drag coefficient is smaller.

关 键 词：多相流 煤燃烧 终端速度 曳力 虚拟区域法 

分 类 号：TK11[动力工程及工程热物理—热能工程]