中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2014年
32期
5750-5756
,共7页
于广滨%刘迪%陈巨辉%戴冰%胡汀%赵磊
于廣濱%劉迪%陳巨輝%戴冰%鬍汀%趙磊
우엄빈%류적%진거휘%대빙%호정%조뢰
亚格子反应速率%大涡模拟%煤燃烧%流化床
亞格子反應速率%大渦模擬%煤燃燒%流化床
아격자반응속솔%대와모의%매연소%류화상
sub-grid reaction rates%large-eddy simulation%coal combustion%fluidized bed
基于涡耗散概念燃烧模型思想,考虑小涡上的化学反应建立亚格子反应模型。分析了流化床内煤颗粒的流动与燃烧过程。模拟了出口处气体组分,采用亚格子反应模型的模拟结果更接近实验值。对于挥发分均相反应,给出了亚格子反应速率与总反应速率随颗粒浓度的分布特性,亚格子反应速率与总反应速率分布趋势基本一致,随着浓度的增加也有上升的趋势。亚格子反应速率占总反应速率的22%左右。对于碳燃烧异相反应,给出了采用亚格子反应模型与未采用亚格子反应模型模拟的反应速率随浓度的分布特性,考虑亚格子反应模型与未考虑亚格子反应模型的模拟结果趋势一致,随着浓度的增加反而有所降低,未考虑亚格子反应模型模拟的反应速率大约为采用亚格子反应模型模拟的80%。
基于渦耗散概唸燃燒模型思想,攷慮小渦上的化學反應建立亞格子反應模型。分析瞭流化床內煤顆粒的流動與燃燒過程。模擬瞭齣口處氣體組分,採用亞格子反應模型的模擬結果更接近實驗值。對于揮髮分均相反應,給齣瞭亞格子反應速率與總反應速率隨顆粒濃度的分佈特性,亞格子反應速率與總反應速率分佈趨勢基本一緻,隨著濃度的增加也有上升的趨勢。亞格子反應速率佔總反應速率的22%左右。對于碳燃燒異相反應,給齣瞭採用亞格子反應模型與未採用亞格子反應模型模擬的反應速率隨濃度的分佈特性,攷慮亞格子反應模型與未攷慮亞格子反應模型的模擬結果趨勢一緻,隨著濃度的增加反而有所降低,未攷慮亞格子反應模型模擬的反應速率大約為採用亞格子反應模型模擬的80%。
기우와모산개념연소모형사상,고필소와상적화학반응건립아격자반응모형。분석료류화상내매과립적류동여연소과정。모의료출구처기체조분,채용아격자반응모형적모의결과경접근실험치。대우휘발분균상반응,급출료아격자반응속솔여총반응속솔수과립농도적분포특성,아격자반응속솔여총반응속솔분포추세기본일치,수착농도적증가야유상승적추세。아격자반응속솔점총반응속솔적22%좌우。대우탄연소이상반응,급출료채용아격자반응모형여미채용아격자반응모형모의적반응속솔수농도적분포특성,고필아격자반응모형여미고필아격자반응모형적모의결과추세일치,수착농도적증가반이유소강저,미고필아격자반응모형모의적반응속솔대약위채용아격자반응모형모의적80%。
Based on the eddy dissipation concept (EDC) reaction model, the sub-grid reaction model was presented within small eddy and applied to simulate the flow and combustion behavior of coal particles in fluidized bed combustor. By comparing simulation results with sub-grid reaction model, the simulated gas components at the outlet agreed well with experiment data. For volatile homogeneous reactions, the distributions of the sub-grid and total reaction rates as a function of solid concentration were given. The distributions of sub-grid reaction rates have a similar trend with those of total reaction rates. With the increase of particle concentration, volatile homogeneous reaction rates increase. The sub-grid reaction rates are about 22%of the total reaction rates. The carbon heterogeneous reactions with and without sub-grid reaction model as a function of concentration were also given, which have a similar trend. With the decrease of particle concentration, carbon heterogeneous reaction rates increase. The results without the sub-grid reaction model are about 80%of those with the sub-grid reaction model.