高校化学工程学报
高校化學工程學報
고교화학공정학보
JOURNAL OF CHEMICAL ENGINEERING OF CHINESE UNIVERSITIES
2013年
4期
597-603
,共7页
李超%代正华%孙钟华%李召召%王辅臣
李超%代正華%孫鐘華%李召召%王輔臣
리초%대정화%손종화%리소소%왕보신
气流床气化炉%综合模型%颗粒停留时间分布%气化动力学
氣流床氣化爐%綜閤模型%顆粒停留時間分佈%氣化動力學
기류상기화로%종합모형%과립정류시간분포%기화동역학
entrained flow gasifier%comprehensive model%particle residence time distribution
采用颗粒停留时间分布表征炉内颗粒流动,建立了一种考虑了炉体结构、颗粒粒径以及煤焦反应动力学的气流床气化炉综合模型,其中包含了煤脱挥发份、均相反应、非均相反应、气-固相能量方程、相间传热等子模型。模拟结果与多喷嘴对置式水煤浆气化炉工业运行数据吻合良好,考察了气相组分、温度以及不同粒径颗粒的碳转化率和温度在炉内的一维无因次分布。对模拟结果的分析表明:煤颗粒的预热、脱挥发份和燃烧过程在约30 ms内完成,气化过程占颗粒反应历程的绝大部分;气化炉内100μm以下的小颗粒升温速率快,且温度较高,碳转化率基本接近100%;而200μm以上的大颗粒升温速率较慢,碳转化率较低,影响了气化炉整体碳转化率。
採用顆粒停留時間分佈錶徵爐內顆粒流動,建立瞭一種攷慮瞭爐體結構、顆粒粒徑以及煤焦反應動力學的氣流床氣化爐綜閤模型,其中包含瞭煤脫揮髮份、均相反應、非均相反應、氣-固相能量方程、相間傳熱等子模型。模擬結果與多噴嘴對置式水煤漿氣化爐工業運行數據吻閤良好,攷察瞭氣相組分、溫度以及不同粒徑顆粒的碳轉化率和溫度在爐內的一維無因次分佈。對模擬結果的分析錶明:煤顆粒的預熱、脫揮髮份和燃燒過程在約30 ms內完成,氣化過程佔顆粒反應歷程的絕大部分;氣化爐內100μm以下的小顆粒升溫速率快,且溫度較高,碳轉化率基本接近100%;而200μm以上的大顆粒升溫速率較慢,碳轉化率較低,影響瞭氣化爐整體碳轉化率。
채용과립정류시간분포표정로내과립류동,건립료일충고필료로체결구、과립립경이급매초반응동역학적기류상기화로종합모형,기중포함료매탈휘발빈、균상반응、비균상반응、기-고상능량방정、상간전열등자모형。모의결과여다분취대치식수매장기화로공업운행수거문합량호,고찰료기상조분、온도이급불동립경과립적탄전화솔화온도재로내적일유무인차분포。대모의결과적분석표명:매과립적예열、탈휘발빈화연소과정재약30 ms내완성,기화과정점과립반응역정적절대부분;기화로내100μm이하적소과립승온속솔쾌,차온도교고,탄전화솔기본접근100%;이200μm이상적대과립승온속솔교만,탄전화솔교저,영향료기화로정체탄전화솔。
With taking the effects of gasifier structure, particle size and reaction kinetics on gasification results into account, a comprehensive model of entrained flow gasifier was developed in this study, in which the particle residence time distribution was employed to characterize the particle flow behavior. Submodels of coal devolatilization, homogeneous and heterogeneous reactions, energy balance and heat transfer were included in this model. The simulation results of an OMB (opposed multi-burner) gasifier are in well agreement with industrial operating data. 1-D distributions of gas components, temperature and total carbon conversion in gasifier were obtained. Additionally, profiles of temperature and carbon conversion of particles with different diameters along normalized gasifier length are included as well. Following results can be observed quantitatively: Preheating, devolatilization and combustion of coal particles are completed in about 30 ms. Gasification of particle is the major process in gasifier. Small particles are heated rapidly and converted completely because of having high heat transfer and reaction rate. Carbon conversion ratio of the particles smaller than 100μm reaches about 100%at the outlet of gasifier. However, for the particles larger than 200μm, their temperature increases slowly and carbon conversion ratio is relatively lower.