翅片管换热过程的数值模拟及实验研究
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摘要
换热器是工业传热过程中必不可少的设备,广泛应用于各工业部门。随着科技及工业的发展,要求换热设备紧凑、轻巧、高效并小型化,翅片管换热器和板式换热器成为人们关注较多的两种高效换热器。其中翅片管作为翅片管换热器的核心元件,其质量的优劣直接影响到热交换器的工作性能。本文通过对采用切削一挤压复合成形方法加工的翅片管进行三维有限元分析,研究其热交换过程和传热效果,以便指导其优化设计与加工。
采用三维实体造型软件(CATIA)构建翅片管换热器的三维实体简化模型;选用ANSYS ICEM CFD生成六面体网格,以ANSYS CFX为仿真工具,将流体与翅片管的接触面设置为流固恒热流耦合传热边界,完成了翅片管换热器模型的建立和模拟计算过程;针对模拟计算结果,分别分析了翅片管结构参数、翅片管内外流体对换热效果的影响,获得了翅片间距、厚度、高度以及翅片管外不同流体种类对换热效果的影响规律。
建立了研究翅片管换热特性的实验平台;通过对翅片管强制对流换热过程的数值模拟,获得了其平均传热系数。实验结果表明,翅片间距对平均传热系数影响最大,翅片厚度次之,翅片高度最小;平均传热系数随翅片高度的增大而增大;随翅片间距的减小而增大;随翅片厚度的增大,先增大后减小。通过翅片管的传热优化分析,获得翅片管最优结构参数,实验结果验证了翅片管数值模拟过程的正确性。
Heat exchanger is indispensable in process of industrial heat transfer,and is widely used by each department on industry.With the development of technology and industry,heat exchangers are required of compactness,portability,high efficiency and miniaturization.The fin tube heat exchanger and plate heat exchanger are paid more concentration by people.Fin tubes are the key part of fin tube heat exchangers,which quality are directly related to working characteristic of heat exchanger.In this thesis,in order to optimize design and manufacture,the heat exchanging process and heat transfer effect of fin tube,which is manufactured by means of cutting-extrusing composite technics,are studied with 3D-finite element analysis method.
The simplified 3-D solid model is built with an 3-D solid modeling software(CATIA).The hexahedral element mesh is generated with ANSYS ICEM CFD.Using ANSYS CFX as simulation tool,setting interfaces between fluid and fin tube as fluid-solid coupled heat transfer boundary in condition of invariable heat flux,model establishment and simulation computation of fin tube heat exchanger are completed.
According to simulation results,analyzing the effect of fin tube structure parameters and fluid around fin tube on heat transfer effect,the influence law that pitch,thickness & height of fin and different types of fluid around fin tube affect heat exchange effect is obtained.
An experimental platform of researching heat exchange performance of fin tubes is built. Average heat transfer coefficient is obtained by means of numerical simulation of forced convection heat transfer around fin tube.The experiment results indicate that the effect of fin height on average heat transfer coefficient comes first,the fin spacing second,the fin thickness last.The average heat transfer coefficient increases at the previous period and decrease at the later period with the increase of the thickness of fins,while it increases with the decrease of fin spacing and the increase of fin height.With optimization analysis of heat transfer,optimum structure parameters of fin tube are obtained,and the experiment results confirms the validity of numerical simulation.
采用三维实体造型软件(CATIA)构建翅片管换热器的三维实体简化模型;选用ANSYS ICEM CFD生成六面体网格,以ANSYS CFX为仿真工具,将流体与翅片管的接触面设置为流固恒热流耦合传热边界,完成了翅片管换热器模型的建立和模拟计算过程;针对模拟计算结果,分别分析了翅片管结构参数、翅片管内外流体对换热效果的影响,获得了翅片间距、厚度、高度以及翅片管外不同流体种类对换热效果的影响规律。
建立了研究翅片管换热特性的实验平台;通过对翅片管强制对流换热过程的数值模拟,获得了其平均传热系数。实验结果表明,翅片间距对平均传热系数影响最大,翅片厚度次之,翅片高度最小;平均传热系数随翅片高度的增大而增大;随翅片间距的减小而增大;随翅片厚度的增大,先增大后减小。通过翅片管的传热优化分析,获得翅片管最优结构参数,实验结果验证了翅片管数值模拟过程的正确性。
Heat exchanger is indispensable in process of industrial heat transfer,and is widely used by each department on industry.With the development of technology and industry,heat exchangers are required of compactness,portability,high efficiency and miniaturization.The fin tube heat exchanger and plate heat exchanger are paid more concentration by people.Fin tubes are the key part of fin tube heat exchangers,which quality are directly related to working characteristic of heat exchanger.In this thesis,in order to optimize design and manufacture,the heat exchanging process and heat transfer effect of fin tube,which is manufactured by means of cutting-extrusing composite technics,are studied with 3D-finite element analysis method.
The simplified 3-D solid model is built with an 3-D solid modeling software(CATIA).The hexahedral element mesh is generated with ANSYS ICEM CFD.Using ANSYS CFX as simulation tool,setting interfaces between fluid and fin tube as fluid-solid coupled heat transfer boundary in condition of invariable heat flux,model establishment and simulation computation of fin tube heat exchanger are completed.
According to simulation results,analyzing the effect of fin tube structure parameters and fluid around fin tube on heat transfer effect,the influence law that pitch,thickness & height of fin and different types of fluid around fin tube affect heat exchange effect is obtained.
An experimental platform of researching heat exchange performance of fin tubes is built. Average heat transfer coefficient is obtained by means of numerical simulation of forced convection heat transfer around fin tube.The experiment results indicate that the effect of fin height on average heat transfer coefficient comes first,the fin spacing second,the fin thickness last.The average heat transfer coefficient increases at the previous period and decrease at the later period with the increase of the thickness of fins,while it increases with the decrease of fin spacing and the increase of fin height.With optimization analysis of heat transfer,optimum structure parameters of fin tube are obtained,and the experiment results confirms the validity of numerical simulation.
引文
[1]何雅玲.对流换热及其强化的理论与实验研究最新进展[M].北京:高等教育出版社,2005:155-167.
[2]马庆芳.换热器[M].北京:机械工业出版社,1983:34-78.
[3]朱聘冠.换热器原理及计算[M].北京:清华大学出版社,1987:23-45.
[4]马昌文.换热器内的对流传热[M].北京:科学出版社,1986:15-33.
[5]夏伟,吴斌,汤勇,李元元.整体翅片管的劈切-挤压加工[J].中国有色金属学报,2001:11(1):27-30.
[6]吴斌,汤勇,夏伟,叶邦彦.一种新型三维整体翅片管的双面犁加工[J].工具技术,2000,12(1):40-43.
[7]Adel Mahmmod Hassan,Amer M.S.Momani.Further improvement in some properties of shot peened components using the burnishing process[J].Machine Tools & Manufacture,2000,40:3-7.
[8]李言.功能表面切削-挤压复合成型方法的研究[J].西安理工大学学报,1999.6:5-9.
[9]钱颂文.换热器管束流体力学与传热[M].北京:中国石化出版社,2001:81-98.
[10]余建祖.换热器原理与设计[M].北京:北京航空航天大学出版社,2006:100-115.
[11]陈占秀.纵流式换热器流动与传热特性的研究[D].天津:天津大学,2003.
[12]Myers G.E,Michell J.W.,and Lindeman C.F.The Transient Response of Heat Exchangers Having an Infinite capacitance Rate Fluid[J].ASME.Journal of Heat Transfer,Vol.92,1980.
[13]Yamashite H,Izumi R.,and Yamaguchi S.Analysis of the Dynamic Characteristic of crossflow Heat Exchangers with Both Fluids Unmixed[J].ASME Bulleton,Vol.21,1987.
[14]Tao W Q,Qu Z G,He Y L.A novel segregated algorithm for incompressible fluid flow and heat transfer problems[J].Numerical Heat Transfer,Part B,2004,45:1-17.
[15]Hou Pingli,Tao Wenquan,Yu Maozheng.Refinement of the convective boundedness criterion of Gaskell and Lau[J].Engineering Computations,2003,20(8):1023-1043.
[16]Liu X L,Tao W Q,He Y L,Wang Q W.Control of convergence in a computational fluid dynamic simulations using fuzzy logic[J].SCI CHINA SER E 45(5),OCT 2002.
[17]李安桂,吴业正.在综合换热作用下矩形直肋散热器换热特性[J].西安冶金建筑学院学报,1994,26(1):48-53.
[18]崔明贤,江菊元,福顺.高效传热的铝合金散热器[J].天津理工学院学报,2001,(S1).
[19]陈景仁.湍流模型及有限元分析法[M].上海:上海交通大学出版社,1989,2:65-78.
[20]张政,张素平.厚翅片管内流体流动和传热的数值分析[J].工程热物理学报,1994/15/04 P:430-434.
[21]陶文铨,何雅玲.对流换热及其强化的理论与实验研究最新进展[M].北京:高等教育出版社, 2005:155-167.
[22]王福军.计算流体力学分析[M].北京:清华大学出版社,2004:13-172.
[23](美)约翰D.安德森(John D.Anderson).计算流体力学基础及其应用[M].北京:机械工业出版社,2007:26-55.
[24]王秋旺.传热学重点难点及典型题精解[M].西安:西安交通大学出版社,2000:11-82.
[25]杨世铭,陶文铨.传热学(第三版)[M].北京:高等教育出版社,1998:26-136.
[26]李人宪.有限体积法基础[M].北京:国防工业出版社,2005:10-13.
[27]唐俊.CATIA V5 R14中文版实例教程[M].北京:清华大学出版社,2005:5-10.
[28]桂小林.网格技术导论[M].北京:北京邮电大学出版社,2005:28-41.
[29]杜平安,甘娥忠,于亚婷.有限元法原理建模及应用[M].北京:国防工业出版社,2004:10-12.
[30]Mark Filipiak.Mesh Generation[M].Edinburgh Parallel Computing Centre The University of Edinburgh.November 1996:5-26.
[31]文书明.微流边界层理论及其应用[M].北京:冶金工业出版社,2002:50-100.
[32]许维德.湍流边界层理论[M].哈尔滨:哈尔滨船舶工程学院出版社,1985,4:101-120.
[33]张国智.ANSYS 10.0热力学有限元分析实例指导教程[M].北京:机械工业出版社,2007:20-26.
[34]Jiin-Yuh Jang,Chien-Nan Lin.Two-Dimensional Fin Efficiency of Plate Fin-Tube Heat Exchanger Under Partially and Fully Wet Conditions[J].J.of Thermal Science Vol,11,No3.
[35]R.V.Seeniraj,R.Velraj,N.Lakshmi Narasimhan.Thermal analysis of a finned-robe LHTS module for a solar dynamic power system[J].Heat and Mass Transfer 38(2002):409-417.
[36]廖永平.正交试验法在机械工业中的应用[M].北京:中国农业机械出版社,1984:127-131.
[37]刘文卿.实验设计[M].北京:清华大学出版社,2005:68-71.
[38]曹玉璋.实验传热学[M].北京:国防工业出版社,1999:1-119.
[39]高青.传热管强化传热性能评价方法研究[J].化工机械,19(5).
[40]倪振伟.评价换热器热性能的三项指标[J].工程热物理学报,1984,5(4):387-389.
[41]高青,卓宁.传热管强化传热能质综合分析[J].化工学报,1990,44(1):90-95.
[42]闫全英,刘迎云.热质交换原理与设备[M].北京:机械工业出版社.2006:267-268.
[43]沈维道.工程热力学(第三版)[M].北京:高等教育出版社,2001:29-167.
[44]倪振伟.换热器的熵增计算法与总熵增率[J].工程热物理学报,1998,9(1):4-6.
[45]J.E.Hesselgreaves.Rationalization of second law analysis of heat exchangers[J].HEAT and MASS TRANSFER,2000,2000(43):4189-4204.
[2]马庆芳.换热器[M].北京:机械工业出版社,1983:34-78.
[3]朱聘冠.换热器原理及计算[M].北京:清华大学出版社,1987:23-45.
[4]马昌文.换热器内的对流传热[M].北京:科学出版社,1986:15-33.
[5]夏伟,吴斌,汤勇,李元元.整体翅片管的劈切-挤压加工[J].中国有色金属学报,2001:11(1):27-30.
[6]吴斌,汤勇,夏伟,叶邦彦.一种新型三维整体翅片管的双面犁加工[J].工具技术,2000,12(1):40-43.
[7]Adel Mahmmod Hassan,Amer M.S.Momani.Further improvement in some properties of shot peened components using the burnishing process[J].Machine Tools & Manufacture,2000,40:3-7.
[8]李言.功能表面切削-挤压复合成型方法的研究[J].西安理工大学学报,1999.6:5-9.
[9]钱颂文.换热器管束流体力学与传热[M].北京:中国石化出版社,2001:81-98.
[10]余建祖.换热器原理与设计[M].北京:北京航空航天大学出版社,2006:100-115.
[11]陈占秀.纵流式换热器流动与传热特性的研究[D].天津:天津大学,2003.
[12]Myers G.E,Michell J.W.,and Lindeman C.F.The Transient Response of Heat Exchangers Having an Infinite capacitance Rate Fluid[J].ASME.Journal of Heat Transfer,Vol.92,1980.
[13]Yamashite H,Izumi R.,and Yamaguchi S.Analysis of the Dynamic Characteristic of crossflow Heat Exchangers with Both Fluids Unmixed[J].ASME Bulleton,Vol.21,1987.
[14]Tao W Q,Qu Z G,He Y L.A novel segregated algorithm for incompressible fluid flow and heat transfer problems[J].Numerical Heat Transfer,Part B,2004,45:1-17.
[15]Hou Pingli,Tao Wenquan,Yu Maozheng.Refinement of the convective boundedness criterion of Gaskell and Lau[J].Engineering Computations,2003,20(8):1023-1043.
[16]Liu X L,Tao W Q,He Y L,Wang Q W.Control of convergence in a computational fluid dynamic simulations using fuzzy logic[J].SCI CHINA SER E 45(5),OCT 2002.
[17]李安桂,吴业正.在综合换热作用下矩形直肋散热器换热特性[J].西安冶金建筑学院学报,1994,26(1):48-53.
[18]崔明贤,江菊元,福顺.高效传热的铝合金散热器[J].天津理工学院学报,2001,(S1).
[19]陈景仁.湍流模型及有限元分析法[M].上海:上海交通大学出版社,1989,2:65-78.
[20]张政,张素平.厚翅片管内流体流动和传热的数值分析[J].工程热物理学报,1994/15/04 P:430-434.
[21]陶文铨,何雅玲.对流换热及其强化的理论与实验研究最新进展[M].北京:高等教育出版社, 2005:155-167.
[22]王福军.计算流体力学分析[M].北京:清华大学出版社,2004:13-172.
[23](美)约翰D.安德森(John D.Anderson).计算流体力学基础及其应用[M].北京:机械工业出版社,2007:26-55.
[24]王秋旺.传热学重点难点及典型题精解[M].西安:西安交通大学出版社,2000:11-82.
[25]杨世铭,陶文铨.传热学(第三版)[M].北京:高等教育出版社,1998:26-136.
[26]李人宪.有限体积法基础[M].北京:国防工业出版社,2005:10-13.
[27]唐俊.CATIA V5 R14中文版实例教程[M].北京:清华大学出版社,2005:5-10.
[28]桂小林.网格技术导论[M].北京:北京邮电大学出版社,2005:28-41.
[29]杜平安,甘娥忠,于亚婷.有限元法原理建模及应用[M].北京:国防工业出版社,2004:10-12.
[30]Mark Filipiak.Mesh Generation[M].Edinburgh Parallel Computing Centre The University of Edinburgh.November 1996:5-26.
[31]文书明.微流边界层理论及其应用[M].北京:冶金工业出版社,2002:50-100.
[32]许维德.湍流边界层理论[M].哈尔滨:哈尔滨船舶工程学院出版社,1985,4:101-120.
[33]张国智.ANSYS 10.0热力学有限元分析实例指导教程[M].北京:机械工业出版社,2007:20-26.
[34]Jiin-Yuh Jang,Chien-Nan Lin.Two-Dimensional Fin Efficiency of Plate Fin-Tube Heat Exchanger Under Partially and Fully Wet Conditions[J].J.of Thermal Science Vol,11,No3.
[35]R.V.Seeniraj,R.Velraj,N.Lakshmi Narasimhan.Thermal analysis of a finned-robe LHTS module for a solar dynamic power system[J].Heat and Mass Transfer 38(2002):409-417.
[36]廖永平.正交试验法在机械工业中的应用[M].北京:中国农业机械出版社,1984:127-131.
[37]刘文卿.实验设计[M].北京:清华大学出版社,2005:68-71.
[38]曹玉璋.实验传热学[M].北京:国防工业出版社,1999:1-119.
[39]高青.传热管强化传热性能评价方法研究[J].化工机械,19(5).
[40]倪振伟.评价换热器热性能的三项指标[J].工程热物理学报,1984,5(4):387-389.
[41]高青,卓宁.传热管强化传热能质综合分析[J].化工学报,1990,44(1):90-95.
[42]闫全英,刘迎云.热质交换原理与设备[M].北京:机械工业出版社.2006:267-268.
[43]沈维道.工程热力学(第三版)[M].北京:高等教育出版社,2001:29-167.
[44]倪振伟.换热器的熵增计算法与总熵增率[J].工程热物理学报,1998,9(1):4-6.
[45]J.E.Hesselgreaves.Rationalization of second law analysis of heat exchangers[J].HEAT and MASS TRANSFER,2000,2000(43):4189-4204.