T型管内两相流分配特性数值模拟
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摘要
T型管内气液两相流分配不均易导致换热器偏流和受热不均。为了优化T型管内气液两相流流动,以FLUENT为模拟软件,以流体流动参数和管子几何结构为研究变量,对T型管内流体流动进行数值模拟。发现流体入口液相体积分数越大,入口速度越小,液滴粒径越小,越利于流体均布;同时支管衔接处采取弯管结构较直管结构优越,其中入口速度对流体分布影响最明显,速度相差3个数值即可优化两个出口液相体积分数比差10%左右。结果表明,相应改变流体流动参数和管子几何结构能有效优化T型管内流体流动。
Uneven distribution of gas-liquid two-phase flow in T-tube was easy to cause bias flow and uneven heating in heat exchangers.To optimize the gas-liquid two-phase flow in T-tube,the simulation about influences of flow parameters and tubes geometric structure on distribution of two-phase flow characteristics in T-tube was carried out by FLUENT. It was found that higher volume fraction of liquid phase and slower inlet velocity,and a smaller diameter of liquid drops facilitate even distribution of fluid.Meanwhile,the elbow structure was better than a straight tube at joints of branch tubes,the inlet velocity had most obvious influence on flow distribution,the difference of three units in speed could result in around 10% variation in volume fraction ration between two outlets. The results showed that change the flow parameters and tubes geometric structure correspond could optimize fluid flow in T-tube effectively.
Uneven distribution of gas-liquid two-phase flow in T-tube was easy to cause bias flow and uneven heating in heat exchangers.To optimize the gas-liquid two-phase flow in T-tube,the simulation about influences of flow parameters and tubes geometric structure on distribution of two-phase flow characteristics in T-tube was carried out by FLUENT. It was found that higher volume fraction of liquid phase and slower inlet velocity,and a smaller diameter of liquid drops facilitate even distribution of fluid.Meanwhile,the elbow structure was better than a straight tube at joints of branch tubes,the inlet velocity had most obvious influence on flow distribution,the difference of three units in speed could result in around 10% variation in volume fraction ration between two outlets. The results showed that change the flow parameters and tubes geometric structure correspond could optimize fluid flow in T-tube effectively.
引文
[1]MUELLER A C.Effects of some types of maldistribution on the performance of heat exchangers[J].Heat Transfer Engineering,1987,8(2):75-86.
[2]MUELLER A C,CHIOU J P.Reviewof various types of flowmaldistribution in heat exchanger[J].Heat Transfer Engineering,1988,9(2):36-50.
[3]SIVERT V.Two-phase flowdistribution in heat exchanger mainfolds[D].Trondheim,Norway:Norwegian University of Science and Technology,2003.
[4]MOHAMMAD A,GEORGES B,PIERRE M.General characteristics of two-phase flowdistribution in a compact heat exchanger[J].International Journal of Heat and Mass Transfer,2009,52(1-2):442-450.
[5]杨康,刘吉普,马雯波.基于FLUENT软件的T型三通管湍流数值模拟[J].化工装备技术,2008,29(4):33-36.YANG Kang,LIU Jipu,MA Wenbo.The turbulence numerical simulation of T-tube based on FLUENT software[J].Chemical Equipment Technology,2008,29(4):33-36.
[6]赵铎.水平管内气液两相流流型数值模拟与实验研究[D].青岛:中国石油大学,2007.ZHAO Duo.Numerical simulation and experimental research on flowpattern of gas-liquid flowin horizontal pipe[D].Qingdao:China University of Petroleum,2007.
[7]罗永浩,杨世铭,王孟浩.T型进口三通对分配联箱流量分配的影响[J].动力工程,1998,18(3):29-33.LUO Yonghao,YANG Shiming,WANG Menghao.The influence of T-tube on distribution of flux in distribution header[J].Power Engineering,1998,18(3):29-33.
[8]罗永浩,杨世铭.锅炉集箱支管流动机理探讨[J].锅炉技术,1997(4):11-13.LUO Yonghao,YANG Shiming.The flowmechanism of boiler header pipe[J].Boiler Technology,1997(4):11-13.
[9]MASAHIRO O,TOMOYUKI H,SACHIYO H.Water flowdistribution in horizontal header contaminated with bubbles[J].International Journal of Multiphase Flow,1999,25(5):827-840.
[10]缪正清,徐通模.集箱与并联管屏系统单相流体的流动特性[J].上海交通大学学报,2000,34(9):1206-1210.MIU Zhengqing,XU Tongmo.The fluid flowcharacteristics of single phase in header and parallel tube system[J].Journal of Shanghai Jiao Tong University,2000,34(9):1206-1210.
[11]WANG C C,YANG K S,TSAI J S,et al.Characteristics of flowdistribution in compact parallel flowheat exchangers part I:typical inlet header[J].Applied Thermal Engineering,2011,31:3226-3242.
[12]CHARRON Y,WHALLEY P B.Gas-liquid annular flowat a vertical tee junction-part flowseparation[J].Multiphase Flow,1995,21(4):569-589.
[13]CHIOU J P.The effect of nonuniform fluid flowdistribution on the thermal performance of solar collector[J].Solar Energy,1982,29(6):487-502.
[14]CHIOU J P.Thermal performance deterioration in crossflowheat exchanger due to the flownonuniformity[J].Journal of Heat Transfer,1978,100(4):580-587.
[15]CHIOU J P.The effect of longitudinal heat conduction on crossflowheat exchanger[J].Journal of Heat Transfer,1978,100(2):346-351.
[16]SAAD S B,CLEMENT P,FOURMIGUE J F,et al.Single phase pressure drop and two-phase distribution in an offset strip fin compact heat exchanger[J].Applied Thermal Engineering,2002,49(6):99-105.
[17]MULLER-MENZEL T.Plate-fin heat exchanger performance reduction in special two-phase flowconditions[J].Cryogenics,1995,35(5):297-301.
[18]陶文铨.数值传热学[M].西安:西安交通大学出版社,2001:1-6.
[19]李亚洁.分配联箱气液两相流的实验及数值模拟研究[D].北京:华北电力大学.2009.LI Yajie.Experimental investigation and numerical simulation on gas-liquid two phase flowin distribution header[D].Beijing:North China Electric Power University,2009.
[20]ECKHARD K,BRAHMA N,ALEXANDR Z,et al.Experimental and numerical studies of volume fraction distribution in rectangular bubble columns[J].Nuclear Engineering and Design,2007,237(4):399-408.
[2]MUELLER A C,CHIOU J P.Reviewof various types of flowmaldistribution in heat exchanger[J].Heat Transfer Engineering,1988,9(2):36-50.
[3]SIVERT V.Two-phase flowdistribution in heat exchanger mainfolds[D].Trondheim,Norway:Norwegian University of Science and Technology,2003.
[4]MOHAMMAD A,GEORGES B,PIERRE M.General characteristics of two-phase flowdistribution in a compact heat exchanger[J].International Journal of Heat and Mass Transfer,2009,52(1-2):442-450.
[5]杨康,刘吉普,马雯波.基于FLUENT软件的T型三通管湍流数值模拟[J].化工装备技术,2008,29(4):33-36.YANG Kang,LIU Jipu,MA Wenbo.The turbulence numerical simulation of T-tube based on FLUENT software[J].Chemical Equipment Technology,2008,29(4):33-36.
[6]赵铎.水平管内气液两相流流型数值模拟与实验研究[D].青岛:中国石油大学,2007.ZHAO Duo.Numerical simulation and experimental research on flowpattern of gas-liquid flowin horizontal pipe[D].Qingdao:China University of Petroleum,2007.
[7]罗永浩,杨世铭,王孟浩.T型进口三通对分配联箱流量分配的影响[J].动力工程,1998,18(3):29-33.LUO Yonghao,YANG Shiming,WANG Menghao.The influence of T-tube on distribution of flux in distribution header[J].Power Engineering,1998,18(3):29-33.
[8]罗永浩,杨世铭.锅炉集箱支管流动机理探讨[J].锅炉技术,1997(4):11-13.LUO Yonghao,YANG Shiming.The flowmechanism of boiler header pipe[J].Boiler Technology,1997(4):11-13.
[9]MASAHIRO O,TOMOYUKI H,SACHIYO H.Water flowdistribution in horizontal header contaminated with bubbles[J].International Journal of Multiphase Flow,1999,25(5):827-840.
[10]缪正清,徐通模.集箱与并联管屏系统单相流体的流动特性[J].上海交通大学学报,2000,34(9):1206-1210.MIU Zhengqing,XU Tongmo.The fluid flowcharacteristics of single phase in header and parallel tube system[J].Journal of Shanghai Jiao Tong University,2000,34(9):1206-1210.
[11]WANG C C,YANG K S,TSAI J S,et al.Characteristics of flowdistribution in compact parallel flowheat exchangers part I:typical inlet header[J].Applied Thermal Engineering,2011,31:3226-3242.
[12]CHARRON Y,WHALLEY P B.Gas-liquid annular flowat a vertical tee junction-part flowseparation[J].Multiphase Flow,1995,21(4):569-589.
[13]CHIOU J P.The effect of nonuniform fluid flowdistribution on the thermal performance of solar collector[J].Solar Energy,1982,29(6):487-502.
[14]CHIOU J P.Thermal performance deterioration in crossflowheat exchanger due to the flownonuniformity[J].Journal of Heat Transfer,1978,100(4):580-587.
[15]CHIOU J P.The effect of longitudinal heat conduction on crossflowheat exchanger[J].Journal of Heat Transfer,1978,100(2):346-351.
[16]SAAD S B,CLEMENT P,FOURMIGUE J F,et al.Single phase pressure drop and two-phase distribution in an offset strip fin compact heat exchanger[J].Applied Thermal Engineering,2002,49(6):99-105.
[17]MULLER-MENZEL T.Plate-fin heat exchanger performance reduction in special two-phase flowconditions[J].Cryogenics,1995,35(5):297-301.
[18]陶文铨.数值传热学[M].西安:西安交通大学出版社,2001:1-6.
[19]李亚洁.分配联箱气液两相流的实验及数值模拟研究[D].北京:华北电力大学.2009.LI Yajie.Experimental investigation and numerical simulation on gas-liquid two phase flowin distribution header[D].Beijing:North China Electric Power University,2009.
[20]ECKHARD K,BRAHMA N,ALEXANDR Z,et al.Experimental and numerical studies of volume fraction distribution in rectangular bubble columns[J].Nuclear Engineering and Design,2007,237(4):399-408.