化学反应工程与工艺
化學反應工程與工藝
화학반응공정여공예
CHEMICAL REACTION ENGINEERING AND TECHNOLOGY
2015年
3期
254-261
,共8页
圆盘反应器%流场%功率%膜厚%数值模拟
圓盤反應器%流場%功率%膜厚%數值模擬
원반반응기%류장%공솔%막후%수치모의
rotating disc reactor%flow field%power%film thickness%numerical simulation
以圆盘反应器的开发和应用为背景，根据反应器内气液两相的流动特点和接触方式，采用流体体积函数（VOF）模型研究圆盘表面液膜厚度、速度分布和槽内液相流型，得到反应器的流场特性。从轴功率、持液量两方面对反应器性能进行研究，并考察了流场和性能的关系。结果表明，圆盘表面液膜分为起始区、加速区和匀速区。起始区液膜厚，速度慢，部分液体回流；加速区液膜变薄，加速，表面更新快；匀速区膜厚和速度变化较小。液相主体以Stewartson流型为主，盘间距对液相流型影响明显。圆盘液膜与槽内液相通过“垂直涡”进行物质传递，当圆盘间距与圆盘直径之比（L/D）为0.2~0.4时，最有利于两者混合和物质传递。将数值模拟和量纲分析结合，得到功率数（NP）和平均膜厚表达式，并与文献进行比较，表明计算流体力学（CFD）方法能够较好的模拟圆盘反应器内流体力学特性，预测流场和性能。
以圓盤反應器的開髮和應用為揹景，根據反應器內氣液兩相的流動特點和接觸方式，採用流體體積函數（VOF）模型研究圓盤錶麵液膜厚度、速度分佈和槽內液相流型，得到反應器的流場特性。從軸功率、持液量兩方麵對反應器性能進行研究，併攷察瞭流場和性能的關繫。結果錶明，圓盤錶麵液膜分為起始區、加速區和勻速區。起始區液膜厚，速度慢，部分液體迴流；加速區液膜變薄，加速，錶麵更新快；勻速區膜厚和速度變化較小。液相主體以Stewartson流型為主，盤間距對液相流型影響明顯。圓盤液膜與槽內液相通過“垂直渦”進行物質傳遞，噹圓盤間距與圓盤直徑之比（L/D）為0.2~0.4時，最有利于兩者混閤和物質傳遞。將數值模擬和量綱分析結閤，得到功率數（NP）和平均膜厚錶達式，併與文獻進行比較，錶明計算流體力學（CFD）方法能夠較好的模擬圓盤反應器內流體力學特性，預測流場和性能。
이원반반응기적개발화응용위배경，근거반응기내기액량상적류동특점화접촉방식，채용류체체적함수（VOF）모형연구원반표면액막후도、속도분포화조내액상류형，득도반응기적류장특성。종축공솔、지액량량방면대반응기성능진행연구，병고찰료류장화성능적관계。결과표명，원반표면액막분위기시구、가속구화균속구。기시구액막후，속도만，부분액체회류；가속구액막변박，가속，표면경신쾌；균속구막후화속도변화교소。액상주체이Stewartson류형위주，반간거대액상류형영향명현。원반액막여조내액상통과“수직와”진행물질전체，당원반간거여원반직경지비（L/D）위0.2~0.4시，최유리우량자혼합화물질전체。장수치모의화량강분석결합，득도공솔수（NP）화평균막후표체식，병여문헌진행비교，표명계산류체역학（CFD）방법능구교호적모의원반반응기내류체역학특성，예측류장화성능。
The aim of this paper is to explore the application of CFD in RDC design, by using the volume of fluid model. The film thickness and velocity distribution on the disc surface, bulk liquid flow pattern have been numerically simulated in the reactor. The performance of the reactor, especially the power and the liquid thickness have been studied with CFD. The effect of discs spacing on the flow field and performance was also investigated. The result showed that the liquid film on the disc surface according to its characteristic can be divided into initial region, accelerating region and uniform region. In initial region, the liquid film is the thickest and its motion slowest, and party of the liquid back flow. In accelerating region, the liquid film is thinner and faster. In uniform region, film thickness and velocity is nearly constant. The liquid flow pattern is Stewartson flow and discs spacing have major influence on liquid flow pattern. "Vertical vortex" is the main way of mass exchange between discs and tank. WhenL/D is between 0.2 and 0.4, it is beneficial to mixing in the tank. Based on numerical simulation and dimensional analysis, the correlation equation of power number and the expression of average film thickness were obtained. Comparing with the literature, it was showed that CFD method can simulate the hydrodynamics of disc rotating reactor and predict its flow field and performance perfectly.
