新型径向叶片式旋转床压降分析及气相流场模拟
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摘要
针对折流式旋转床压降高、能耗大的问题,提出了一种新型超重力旋转床设备——径向叶片式旋转床。首先,对该旋转床的压降进行了理论分析和建模,并利用水-空气体系进行了实验研究。通过改变气量、转速和液量探究了新型径向叶片式旋转床压降的变化规律,结果表明压降随气量、转速和液量的增加而增加,且随着气量和转速的增加,液量对压降的贡献逐渐减小。压降模型的预测值与实验数据的相对偏差基本在10%以内,表明模型可以较好地预测新型径向叶片式旋转床的压降。另外,通过计算流体力学(CFD)软件的模拟获得了旋转床内气相流场和压力分布的结果,发现转子内压降是总压降的主要部分;气体进入转子后会因叶片作用使得周向速度变大,并在转子外缘处达到最大值;气体的进口流速将会影响旋转床内的气相分布。利用实验数据对CFD模拟结果进行了验证,两者的相对偏差在10%左右。
A new kind of high-gravity device—the rotating bed with radial blades—has been developed to reduce the pressure drop and power consumption of rotating zigzag bed. Firstly,the pressure drop of rotating bed with radial blades was theoretically analyzed,and the model of pressure drop was established. Then experimental study was conducted using water-air system. The effects of several factors on pressure drop of the rotating bed were studied by changing the gas flow rate,rotational speed and liquid flow rate. It showed that the pressure drop increased respectively with the increase of gas flow rate,rotational speed and liquid flow rate. The contribution of liquid flow to pressure drop gradually decreases with the increase of gas flow rate and rotating speed. Compared with the experimental results,the predicted values of the proposed model relatively deviate by less than 10%,which indicates that the model can properly predict pressure drop. Computational fluid dynamics(CFD)simulation produced the gas flow field and pressure distribution of the rotating bed,and it was found that the pressure drop inside the rotor is the main part of the total pressure drop. When the gas enters the rotor,it was subjected to blades motion thus increasing the circumferential velocity,which reaches the maximum at the outer edge of the rotor. Additionally,the gas phase distribution would be affected by the inlet gas velocity in the rotating bed. The relative deviation between the CFD simulation result and the experimental data was about 10%.
A new kind of high-gravity device—the rotating bed with radial blades—has been developed to reduce the pressure drop and power consumption of rotating zigzag bed. Firstly,the pressure drop of rotating bed with radial blades was theoretically analyzed,and the model of pressure drop was established. Then experimental study was conducted using water-air system. The effects of several factors on pressure drop of the rotating bed were studied by changing the gas flow rate,rotational speed and liquid flow rate. It showed that the pressure drop increased respectively with the increase of gas flow rate,rotational speed and liquid flow rate. The contribution of liquid flow to pressure drop gradually decreases with the increase of gas flow rate and rotating speed. Compared with the experimental results,the predicted values of the proposed model relatively deviate by less than 10%,which indicates that the model can properly predict pressure drop. Computational fluid dynamics(CFD)simulation produced the gas flow field and pressure distribution of the rotating bed,and it was found that the pressure drop inside the rotor is the main part of the total pressure drop. When the gas enters the rotor,it was subjected to blades motion thus increasing the circumferential velocity,which reaches the maximum at the outer edge of the rotor. Additionally,the gas phase distribution would be affected by the inlet gas velocity in the rotating bed. The relative deviation between the CFD simulation result and the experimental data was about 10%.
引文
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[10]张斌,李育敏,耿康生,等.折流式旋转床气液比表面积的实验研究及CFD模拟[J].化工进展,2017,36(5):1635-1641.ZHANG B,LI Y M,GENG K S,et al.Experimental and CFD simulation on gas-liquid effective interfacial area in rotating zigzag bed[J].Chemical Industry and Engineering Progress,2017,36(5):1635-1641.
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[2]刘有智.超重力化工过程与技术[M].北京:国防工业出版社,2009:5.LIU Y Z.Chemical engineering process and technology in high gravity[M].Beijing:National Defense Industry Press,2009:5.
[3]李振虎,郭锴,陈建铭,等.旋转填充床气相压降特性研究[J].北京化工大学学报,1999,26(4):5-10.LI Z H,GUO K,CHEN J M,et al.Research into characteristics of gas pressure drop of a rotating packed bed[J].Journal of Beijing University of Chemical Technology,1999,26(4):5-10.
[4]王延军,阮奇,苏宁子,等.三角形螺旋填料旋转床气相压降特性[J].化学工业与工程,2010,27(3):253-258.WANG Y J,RUAN Q,SU N Z,et al.Gas phase pressure drop characteristics in rotating packed bed with triangular spiral packing[J].Journal of Chemical Industry&Engineering,2010,27(3):253-258.
[5]KUMAR M P,RAO D P.Studies on a high-gravity gas-liquid contactor[J].Industrial&Engineering Chemistry Research,1990,2(5):917-920.
[6]CHANDRA A,GOSWAMI P S,RAO D P.Characteristics of flow in a rotating packed bed(HIGEE)with split packing[J].Industrial&Engineering Chemistry Research,2005,44(11):4051-4060.
[7]LI Y M,JI J B,XU Z C,et al.Pressure drop model on rotating zigzag bed as a new high-gravity technology[J].Industrial&Engineering Chemistry Research,2013,52(12):4638-4649.
[8]YANG W J,WANG Y D,CHEN J F,et al.Computational fluid dynamic simulation of fluid flow in a rotating packed bed[J].Chemical Engineering Journal,2009,156(3):582-587.
[9]孙润林,向阳,初广文,等.旋转填充床气相流场模拟与验证[J].北京化工大学学报(自然科学版),2012,39(4):6-11.SUN R L,XIANG Y,CHU G W,et al.Computational fluid dynamics(CFD)simulation and validation of the gas flow field in a rotating packed bed[J].Journal of Beijing University of Chemical Technology(Natural Science),2012,39(4):6-11.
[10]张斌,李育敏,耿康生,等.折流式旋转床气液比表面积的实验研究及CFD模拟[J].化工进展,2017,36(5):1635-1641.ZHANG B,LI Y M,GENG K S,et al.Experimental and CFD simulation on gas-liquid effective interfacial area in rotating zigzag bed[J].Chemical Industry and Engineering Progress,2017,36(5):1635-1641.
[11]LIN C C,JIAN G S.Characteristics of a rotating packed bed equipped with blade packings[J].Separation and Purification Technology,2007,54(1):51-60.
[12]计建炳,王良华,徐之超,等.折流式超重力场旋转床装置:01134321.4[P].2004-11-10.JI J B,WANG L H,XU Z C,et al.Equipment of zigzag high-gravity rotating beds:CN01134321.4[P].2004-11-10.
[13]何潮洪,冯霄.化工原理[M].北京:科学出版社,2001:51-52.HE C H,FENG X.Principle of chemical engineering[M].Beijing:Science Press,2001:51-52.