化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
9期
3323-3330
,共8页
杨旭%刘雅宁%余剑%蒋富明%韩永生%许光文%葛蔚
楊旭%劉雅寧%餘劍%蔣富明%韓永生%許光文%葛蔚
양욱%류아저%여검%장부명%한영생%허광문%갈위
微型流化床%混合%喷口结构%数值模拟%优化
微型流化床%混閤%噴口結構%數值模擬%優化
미형류화상%혼합%분구결구%수치모의%우화
micro fluidized bed%mixing%injector structure%numerical simulation%optimization
微型流化床反应分析仪是中国科学院过程工程研究所研制的具有等温微分反应特性,且适合于气固反应分析的新仪器。细微样品与高温流化介质的瞬间混合是该仪器实现等温微分的必要条件。针对如何满足该要求,基于欧拉多流体模型对连接不同进样器的微型反应器本体进行了三维数值模拟,得到了不同喷口结构和位置下的流动图景及混合区浓度的相对标准偏差曲线,定量表征了各种进样器的混合质量。同时采用高速摄像手段获得了冷态实验中颗粒流动的快照,验证了模拟计算结果的可靠性。模拟结果对脉冲射流微量进样器结构的优化提出了如下建议:进样细管应避免采用弯角喷口,弯角结构会导致脉冲进样载流气喷出方向与流化气流相逆,使得细微颗粒试样堆积滞留,影响混合效果。
微型流化床反應分析儀是中國科學院過程工程研究所研製的具有等溫微分反應特性,且適閤于氣固反應分析的新儀器。細微樣品與高溫流化介質的瞬間混閤是該儀器實現等溫微分的必要條件。針對如何滿足該要求,基于歐拉多流體模型對連接不同進樣器的微型反應器本體進行瞭三維數值模擬,得到瞭不同噴口結構和位置下的流動圖景及混閤區濃度的相對標準偏差麯線,定量錶徵瞭各種進樣器的混閤質量。同時採用高速攝像手段穫得瞭冷態實驗中顆粒流動的快照,驗證瞭模擬計算結果的可靠性。模擬結果對脈遲射流微量進樣器結構的優化提齣瞭如下建議:進樣細管應避免採用彎角噴口,彎角結構會導緻脈遲進樣載流氣噴齣方嚮與流化氣流相逆,使得細微顆粒試樣堆積滯留,影響混閤效果。
미형류화상반응분석의시중국과학원과정공정연구소연제적구유등온미분반응특성,차괄합우기고반응분석적신의기。세미양품여고온류화개질적순간혼합시해의기실현등온미분적필요조건。침대여하만족해요구,기우구랍다류체모형대련접불동진양기적미형반응기본체진행료삼유수치모의,득도료불동분구결구화위치하적류동도경급혼합구농도적상대표준편차곡선,정량표정료각충진양기적혼합질량。동시채용고속섭상수단획득료랭태실험중과립류동적쾌조,험증료모의계산결과적가고성。모의결과대맥충사류미량진양기결구적우화제출료여하건의:진양세관응피면채용만각분구,만각결구회도치맥충진양재류기분출방향여류화기류상역,사득세미과립시양퇴적체류,영향혼합효과。
The micro fluidized bed reaction analyzer (MFBRA) developed by Institute of Process Engineering, Chinese Academy of Sciences has isothermal differential characteristics and is suitable for gas-solids fast reaction analysis, including the measurement of reaction rate and kinetic parameters. The instantaneously intensive particle mixing between trace sample in milligrams and high-temperature fluidized material is the essential condition to keep isothermal differential characteristics of the micro fluidized bed reactor. Therefore a three-dimensional numerical simulation based on the Eulerian multi-fluid model was performed for the micro fluidized bed connected with different gas jet structures. The instantaneous flow structures and quantitative mixing characterizations for different injector structures and locations were obtained. Experiments were conducted through measurements using high speed camera to capture the instantaneous solids flow pictures in the bed. Comparison revealed good qualitative agreement between experiment and simulation. The simulation results suggested that the injector should avoid the bending angle that confronted the injected gas with the fluidizing gas or left the trace sample in the injector.