化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2015年
6期
2049-2054
,共6页
罗燕%周剑秋%郭钊%余蓓%熊卉%杨侠
囉燕%週劍鞦%郭釗%餘蓓%熊卉%楊俠
라연%주검추%곽쇠%여배%웅훼%양협
撞击流%反应器%混合%数值模拟
撞擊流%反應器%混閤%數值模擬
당격류%반응기%혼합%수치모의
impinging stream%reactors%blend%numerical simulation
在混合时间理论计算基础上利用CFD技术模拟连续操作的LISR混合过程,数值计算与验证混合时间的变化规律。结果表明,随着输入比有效功率增大,混合时间先急剧减小后逐渐趋于平稳;LISR撞击区一次撞击局部混合时间在0.25 s以内,与经验公式或理论公式计算所得结果在数量级上完全一致,证明数值方法分析一次撞击局部混合时间是可行的,而且可以弥补实验无法测定中间过程参量的不足;进一步数值分析宏观混合时间与微观混合时间发现,二者大小相差1个数量级,但二者变化规律处于一种联动平衡状态,该结果与前期理论分析结果一致;本研究所得结论可为后续LISR混合强化机理与性能研究提供定量参考。
在混閤時間理論計算基礎上利用CFD技術模擬連續操作的LISR混閤過程,數值計算與驗證混閤時間的變化規律。結果錶明,隨著輸入比有效功率增大,混閤時間先急劇減小後逐漸趨于平穩;LISR撞擊區一次撞擊跼部混閤時間在0.25 s以內,與經驗公式或理論公式計算所得結果在數量級上完全一緻,證明數值方法分析一次撞擊跼部混閤時間是可行的,而且可以瀰補實驗無法測定中間過程參量的不足;進一步數值分析宏觀混閤時間與微觀混閤時間髮現,二者大小相差1箇數量級,但二者變化規律處于一種聯動平衡狀態,該結果與前期理論分析結果一緻;本研究所得結論可為後續LISR混閤彊化機理與性能研究提供定量參攷。
재혼합시간이론계산기출상이용CFD기술모의련속조작적LISR혼합과정,수치계산여험증혼합시간적변화규률。결과표명,수착수입비유효공솔증대,혼합시간선급극감소후축점추우평은;LISR당격구일차당격국부혼합시간재0.25 s이내,여경험공식혹이론공식계산소득결과재수량급상완전일치,증명수치방법분석일차당격국부혼합시간시가행적,이차가이미보실험무법측정중간과정삼량적불족;진일보수치분석굉관혼합시간여미관혼합시간발현,이자대소상차1개수량급,단이자변화규률처우일충련동평형상태,해결과여전기이론분석결과일치;본연구소득결론가위후속LISR혼합강화궤리여성능연구제공정량삼고。
On the basis of theoretical calculation, the mixing process under continuous operation in liquid impinging streams reactor (LISR) was simulated by CFD and the change of mixing time was calculated and verified numerically. With increasing effective specific power, mixing time decreased rapidly at first and then tended to be smooth and steady. The local mixing time in one stroke of impinging mixing was less than 0.25 s, which fully agreed with the order of magnitude figured out by empirical model and theoretical model. It was demonstrated that using the numerical method to analyze local mixing time is feasible. It could also make up for the deficiency of experimental research. To further study macromixing time and micromixing time numerically, it was found that macromixing time was one order of magnitude greater than micromixing time, but both changes were fundamentally consistent and were in a linkage state of equilibrium which was in accordance with our previous theoretical analysis. These conclusions could be used as the mechanism methods and quantitative reference for follow-up study of mixing enhancement mechanism of LISR.