蝶阀的优化设计和流场研究
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摘要
蝶阀作为广泛使用的管道控制设备,它的可靠性、节能性、制造和运行成本对于国民经济具有重要的意义。在蝶阀设计中,关于如何降低蝶阀的流阻、蝶阀流阻的测算、蝶阀水力矩的计算、蝶阀各个开度的非均布载荷情况和强度分析、密封副的分析和计算等一直是设计中的难点。传统设计中一般采用试验分析和查阅设计手册的方法,这不仅耗时较长,而且加大了设计制造成本。本文旨在采用一种现代设计方法——有限单元法,对某型橡胶软密封蝶阀设计的主要难点进行了深入的研究和分析：
(1)阐述了蝶阀的应用领域及其重要意义,介绍了蝶阀的基本结构、基本性能及特点,进而指出了当前蝶阀设计中的主要设计方法和存在的主要问题,导出了本课题的研究背景和研究意义,阐述了与课题相关的流体理论；
(2)建立了某型橡胶软密封蝶阀的参数化几何模型,并建立了结构静力学仿真分析有限元模型,分析了该橡胶软密封蝶阀在全关状态下的应力、变形结果,根据分析结果,改进了该橡胶软密封蝶阀的结构,并取得较好的效果；
(3)为了分析流过蝶阀的流体,建立了一种计算流阻系数的有限元模型、利用Cosmosflow分析了管道的沿程压力损失、计算了蝶阀在多种开度下的流阻系数,通过与实验值比较,证明这种分析计算是有效的；提出了一种能有效减小流阻系数的蝶板过流面,并对这种过流面的流阻系数进行了验证；建立了分析蝶阀流态的有限元模型,并计算了多种开度下的流态,对各个开度的压力、流速和流线进行了分析；
(4)基于水泵站工况的蝶阀,建立一种流固耦合分析的有限元模型,并进行了多开度工况下的流固耦合分析,得出了蝶阀在各个开度的应力和位移值,从而得出了阀门全关状态是应力、应变最大状态的结论；比较了该模型计算出的水力矩结果与理论计算水力矩结果,得出了最大水力矩时蝶阀的开度；分析并且比较了常流量下和变流量下的蝶阀气蚀,得出了各个开度的气蚀系数,得出了容易产生气蚀的情形；提出了应避免阀前后出现高压差工况从而避免气蚀的观点,进而提出几种防止气蚀的方法；
(5)采用ANSYS软件,建立了蝶阀密封分析的有限元模型,获得了密封圈厚度方向压缩位移与径向尺寸的变化关系曲线；分析了蝶板的旋转过程,提出了蝶板与阀体开始接触的最佳旋转角度,并提出了几种改进密封面的方案。
本论文采用有限单元方法,对蝶阀设计存在的强度、刚度、流阻、流态、密封等方面的问题进行了全面的分析,对于实现阀门设计从经验设计向科学设计的逐渐过渡具有重要意义。
The butterfly valve is wildly used as a control device for the pipe. Its reliability, energy efficiency, manufacturing and operating costs for the national economy are of great significance. It has been the difficulties in butterfly design on reducing and calculating flow resistance, calculating water torque, analyzing load conditions and strength under several opening degree of the valve, calculating sealing performance, and so on. In traditional design, designers usually designed butterfly valve by testing and inspection manual, which not only takes longer, and also increased cost. In this dissertation, the main difficulties are investigated in designing the soft rubber seal butterfly valve by the finite element method (FEM). It is expounded as follow:
Firstly, it introduces structure, main performances and features, application fields and significance of butterfly valve. Then the main methods for butterfly valve design and main problems in the methods are reviewed, and then the research background and meaning are discussed. Also related fluent theory is introduced.
Secondly, a parameter geometry model and a structural static finite element model of the butterfly valve are built. Then the stress and deformation of the valve are analyzed in fully closed state. Afterwards, optimize the structure of the butterfly valve and achieve better performance.
Thirdly, in order to analyze the fluid flow through the butterfly valve, the dissertation built a finite element model for calculating the flow resistance coefficient, and calculated the pressure loss of the pipe using Cosmosflow. Then it calculated the flow resistance coefficient of several opening degrees. Compared with experiment result data, the analysis result of flow resistance coefficient is valid. Afterward, optimize the butterfly plate, which can reduce the flow resistance coefficient. Also, a finite element model was built for analyzing valve flow, and the pressure, flow rate and streamlines of several opening degrees were analyzed.
Fourthly, it built a fluid-structure interaction (FSI) finite elements model of butterfly valve working on pump station. And it analyzed the model on several opening degrees conditions. The analysis results show that the valve fully closed when the stress and strain is the largest. Hydraulic torque of the valve was analyzed using the FSI finite elements model on several opening degrees. Compared the hydraulic torque with the result calculated by theory, the opening degree is acquired when the hydraulic torque is the largest. The dissertation analyzed the cavitations erosion under constant flow and variable flow. The cavitations erosion coefficient of several opening degree and conditions which prone to cavitations erosion are acquired by compare the analyzed results. And it point out that butterfly valve should avoid excessive pressure difference between two sides of the valve plate so that control the cavitations erosion. Also it provides several methods to prevent the cavitations erosion.
Lastly, the dissertation built and analyzed a finite elements model for analyzing sealing performance. And obtain the curve between compressed displacement and radial dimension of sealing ring. Then the progress of valve plate's rotation was analyzed, and the best degree when the plate and bottom started to contact is acquired. Also, it proposes several programs to improve sealing the surface.
The dissertation analyzed the strength, stiffness, flow resistance coefficient, flow status and sealing performance in the butterfly valve design using finite element technique. It helps to realize the transition from traditional design to modern design.
(1)阐述了蝶阀的应用领域及其重要意义,介绍了蝶阀的基本结构、基本性能及特点,进而指出了当前蝶阀设计中的主要设计方法和存在的主要问题,导出了本课题的研究背景和研究意义,阐述了与课题相关的流体理论；
(2)建立了某型橡胶软密封蝶阀的参数化几何模型,并建立了结构静力学仿真分析有限元模型,分析了该橡胶软密封蝶阀在全关状态下的应力、变形结果,根据分析结果,改进了该橡胶软密封蝶阀的结构,并取得较好的效果；
(3)为了分析流过蝶阀的流体,建立了一种计算流阻系数的有限元模型、利用Cosmosflow分析了管道的沿程压力损失、计算了蝶阀在多种开度下的流阻系数,通过与实验值比较,证明这种分析计算是有效的；提出了一种能有效减小流阻系数的蝶板过流面,并对这种过流面的流阻系数进行了验证；建立了分析蝶阀流态的有限元模型,并计算了多种开度下的流态,对各个开度的压力、流速和流线进行了分析；
(4)基于水泵站工况的蝶阀,建立一种流固耦合分析的有限元模型,并进行了多开度工况下的流固耦合分析,得出了蝶阀在各个开度的应力和位移值,从而得出了阀门全关状态是应力、应变最大状态的结论；比较了该模型计算出的水力矩结果与理论计算水力矩结果,得出了最大水力矩时蝶阀的开度；分析并且比较了常流量下和变流量下的蝶阀气蚀,得出了各个开度的气蚀系数,得出了容易产生气蚀的情形；提出了应避免阀前后出现高压差工况从而避免气蚀的观点,进而提出几种防止气蚀的方法；
(5)采用ANSYS软件,建立了蝶阀密封分析的有限元模型,获得了密封圈厚度方向压缩位移与径向尺寸的变化关系曲线；分析了蝶板的旋转过程,提出了蝶板与阀体开始接触的最佳旋转角度,并提出了几种改进密封面的方案。
本论文采用有限单元方法,对蝶阀设计存在的强度、刚度、流阻、流态、密封等方面的问题进行了全面的分析,对于实现阀门设计从经验设计向科学设计的逐渐过渡具有重要意义。
The butterfly valve is wildly used as a control device for the pipe. Its reliability, energy efficiency, manufacturing and operating costs for the national economy are of great significance. It has been the difficulties in butterfly design on reducing and calculating flow resistance, calculating water torque, analyzing load conditions and strength under several opening degree of the valve, calculating sealing performance, and so on. In traditional design, designers usually designed butterfly valve by testing and inspection manual, which not only takes longer, and also increased cost. In this dissertation, the main difficulties are investigated in designing the soft rubber seal butterfly valve by the finite element method (FEM). It is expounded as follow:
Firstly, it introduces structure, main performances and features, application fields and significance of butterfly valve. Then the main methods for butterfly valve design and main problems in the methods are reviewed, and then the research background and meaning are discussed. Also related fluent theory is introduced.
Secondly, a parameter geometry model and a structural static finite element model of the butterfly valve are built. Then the stress and deformation of the valve are analyzed in fully closed state. Afterwards, optimize the structure of the butterfly valve and achieve better performance.
Thirdly, in order to analyze the fluid flow through the butterfly valve, the dissertation built a finite element model for calculating the flow resistance coefficient, and calculated the pressure loss of the pipe using Cosmosflow. Then it calculated the flow resistance coefficient of several opening degrees. Compared with experiment result data, the analysis result of flow resistance coefficient is valid. Afterward, optimize the butterfly plate, which can reduce the flow resistance coefficient. Also, a finite element model was built for analyzing valve flow, and the pressure, flow rate and streamlines of several opening degrees were analyzed.
Fourthly, it built a fluid-structure interaction (FSI) finite elements model of butterfly valve working on pump station. And it analyzed the model on several opening degrees conditions. The analysis results show that the valve fully closed when the stress and strain is the largest. Hydraulic torque of the valve was analyzed using the FSI finite elements model on several opening degrees. Compared the hydraulic torque with the result calculated by theory, the opening degree is acquired when the hydraulic torque is the largest. The dissertation analyzed the cavitations erosion under constant flow and variable flow. The cavitations erosion coefficient of several opening degree and conditions which prone to cavitations erosion are acquired by compare the analyzed results. And it point out that butterfly valve should avoid excessive pressure difference between two sides of the valve plate so that control the cavitations erosion. Also it provides several methods to prevent the cavitations erosion.
Lastly, the dissertation built and analyzed a finite elements model for analyzing sealing performance. And obtain the curve between compressed displacement and radial dimension of sealing ring. Then the progress of valve plate's rotation was analyzed, and the best degree when the plate and bottom started to contact is acquired. Also, it proposes several programs to improve sealing the surface.
The dissertation analyzed the strength, stiffness, flow resistance coefficient, flow status and sealing performance in the butterfly valve design using finite element technique. It helps to realize the transition from traditional design to modern design.
引文
[1]杨源泉,阀门设计手册,北京：机械工业出版社,1992,51-320
[2]X.G.Song,L.Wang, Y.C.Park. Analysis and optimization of a butterfly valve disc. Proceedings of the Institution of Mechanical Engineers,2009,223(2):25
[3]Xue Guan,Lin Wang,Seok Heum Baek etal. Multidisciplinary optimization of a butterfly valve. ISA Transactions,2009,48(3):30-31
[4]S.I.Yi,M.K.Shin,M.S.Shin,etal.Optimization of the eccentric check butterfly valve considering the flow characteristics and structural safety. Proceedings of the Institution of Mechanical Engineers,2008,222 (E1):60
[5]Gheorghe BARAN,arme-Anca SAFTA,Florentian BUNEA,etal.Stages of noises and vibrations to a butterfly valvein working with cavitation. University Politechnical of Bucharest Scientific Bulletin,2008,70(4):14
[6]徐滟,王渭.三偏心蝶阀密封接触问题的有限元分析.润滑与密封.2006,(6)：26-30
[7]王万庆,姚磊.连杆蝶阀蝶板的优化设计.通用机械,2007,(9)：76-77
[8]陈敏,汤文成,张逸芳等.阀门密封结构中超弹性接触问题的有限元分析.中国机械工程,2007,(15)：1773-1775
[9]陈晓霞,邢静忠.CAD/CAE集成的三偏心蝶阀参数化设计.工程图学学报,2009,30(1)：37-40
[10]余龙,俞树荣,李淑新.虚拟现实技术在阀门设计中的应用.阀门,2008,(1)：10-14
[11]王建新,吴向前.蝶阀设计时要考虑的因素.通用机械制造,2009,(6)：75
[12]刘飞,张前,沈曦.蝶阀密封结构的技术进化理论分析.阀门,2007,(6)：8-10
[13]郝承明.蝶阀技术的新进展.阀门,2001,(5)：32-34
[14]张银权.舰船蝶阀技术的发展.机电设备,1992,(4)：9-13
[15]陆培文.阀门设计入门与精通.北京：机械工业出版社,2009,32-34
[16]陆培文,孙晓霞,杨炯良.阀门选用手册.北京：机械工业出版社,2001.5,182
[17]郭建林,双偏心软密封防火蝶阀设计,通用机械,2008,(9)：27-28
[18]肖宁.阀门设计与选用.阀门,2005,(5)：39-41
[19]吴绍良.催化裂化装置蝶阀设计改进及维护.炼油设计,1989,19(1)：28-32
[20]李振东.核电液控止回蝶阀设计.阀门,1994,(4)：2-8
[21]薛祖绳,周云龙.工程流体力学.北京：中国电力出版社,1997：20-203
[22]韩占忠,王敬,兰小平.Fluent流体工程仿真计算实例与应用.北京：北京理工大学出版社,2004：20-60
[23]夏泰淳,工程流体力学,上海,上海交通大学出版社,2006.2,55-172
[24]彭凤祥.阀门气蚀研究.阀门,1994,3：11-16
[25]何煜琛,陈涉,陆利锋.Solidworks2005中文版基础及应用教程.北京：电子工业出版社,2005,61-70
[26]王勖成.有限单元法基本原理和数值方法.北京：清华大学出版社,1997,1
[27]黄国权.有限元法基础及ANSYS应用.北京：机械工业出版社,2004,1-2
[28]孙正兴,丁秋林.CAD系统中有限元分析建模方法探讨.微型电脑应用,1995,(2)：36-38
[29]P.H.Kulla. High precision finite elements. Finite Element in Analysis and Design,1997,(26):97-114
[30]陈菊芳,李小宁.门式框架的有限元分析.机床与液压,2002,(5)：167-168
[31]杜平安.有限元网格划分的基本原则.机械设计与制造,2000,(1)：34-36
[32]童成彪Cosmosflow在蝶阀流体分析中的应用.CAD与CAM与制造业信息化,2008,(6)：66-69
[33]赵毅山,程军.流体力学.上海：同济大学出版社,2004,38-39
[34]刘健,李福堂.大口径蝶阀三维流动的数值模拟及分析.流体机械,2008,9：30-32
[35]邵蕴秋.Ansys 8.0有限元分析实例导航.北京：中国铁道出版社,2004,30-60
[36]王瑞文.流体力学及海洋数值模拟基于POD技术的降维方法研究：[首都师范大学博士学位论文].北京：北京师范大学,2007,20-24
[37]张勇巍.发电厂高压差阀门气蚀问题的解决方法.中国设备工程,2006,S1：1
[38]顾永泉.机械密封比压选用原则.石油化工设备.2000,29(2),25-36
[2]X.G.Song,L.Wang, Y.C.Park. Analysis and optimization of a butterfly valve disc. Proceedings of the Institution of Mechanical Engineers,2009,223(2):25
[3]Xue Guan,Lin Wang,Seok Heum Baek etal. Multidisciplinary optimization of a butterfly valve. ISA Transactions,2009,48(3):30-31
[4]S.I.Yi,M.K.Shin,M.S.Shin,etal.Optimization of the eccentric check butterfly valve considering the flow characteristics and structural safety. Proceedings of the Institution of Mechanical Engineers,2008,222 (E1):60
[5]Gheorghe BARAN,arme-Anca SAFTA,Florentian BUNEA,etal.Stages of noises and vibrations to a butterfly valvein working with cavitation. University Politechnical of Bucharest Scientific Bulletin,2008,70(4):14
[6]徐滟,王渭.三偏心蝶阀密封接触问题的有限元分析.润滑与密封.2006,(6)：26-30
[7]王万庆,姚磊.连杆蝶阀蝶板的优化设计.通用机械,2007,(9)：76-77
[8]陈敏,汤文成,张逸芳等.阀门密封结构中超弹性接触问题的有限元分析.中国机械工程,2007,(15)：1773-1775
[9]陈晓霞,邢静忠.CAD/CAE集成的三偏心蝶阀参数化设计.工程图学学报,2009,30(1)：37-40
[10]余龙,俞树荣,李淑新.虚拟现实技术在阀门设计中的应用.阀门,2008,(1)：10-14
[11]王建新,吴向前.蝶阀设计时要考虑的因素.通用机械制造,2009,(6)：75
[12]刘飞,张前,沈曦.蝶阀密封结构的技术进化理论分析.阀门,2007,(6)：8-10
[13]郝承明.蝶阀技术的新进展.阀门,2001,(5)：32-34
[14]张银权.舰船蝶阀技术的发展.机电设备,1992,(4)：9-13
[15]陆培文.阀门设计入门与精通.北京：机械工业出版社,2009,32-34
[16]陆培文,孙晓霞,杨炯良.阀门选用手册.北京：机械工业出版社,2001.5,182
[17]郭建林,双偏心软密封防火蝶阀设计,通用机械,2008,(9)：27-28
[18]肖宁.阀门设计与选用.阀门,2005,(5)：39-41
[19]吴绍良.催化裂化装置蝶阀设计改进及维护.炼油设计,1989,19(1)：28-32
[20]李振东.核电液控止回蝶阀设计.阀门,1994,(4)：2-8
[21]薛祖绳,周云龙.工程流体力学.北京：中国电力出版社,1997：20-203
[22]韩占忠,王敬,兰小平.Fluent流体工程仿真计算实例与应用.北京：北京理工大学出版社,2004：20-60
[23]夏泰淳,工程流体力学,上海,上海交通大学出版社,2006.2,55-172
[24]彭凤祥.阀门气蚀研究.阀门,1994,3：11-16
[25]何煜琛,陈涉,陆利锋.Solidworks2005中文版基础及应用教程.北京：电子工业出版社,2005,61-70
[26]王勖成.有限单元法基本原理和数值方法.北京：清华大学出版社,1997,1
[27]黄国权.有限元法基础及ANSYS应用.北京：机械工业出版社,2004,1-2
[28]孙正兴,丁秋林.CAD系统中有限元分析建模方法探讨.微型电脑应用,1995,(2)：36-38
[29]P.H.Kulla. High precision finite elements. Finite Element in Analysis and Design,1997,(26):97-114
[30]陈菊芳,李小宁.门式框架的有限元分析.机床与液压,2002,(5)：167-168
[31]杜平安.有限元网格划分的基本原则.机械设计与制造,2000,(1)：34-36
[32]童成彪Cosmosflow在蝶阀流体分析中的应用.CAD与CAM与制造业信息化,2008,(6)：66-69
[33]赵毅山,程军.流体力学.上海：同济大学出版社,2004,38-39
[34]刘健,李福堂.大口径蝶阀三维流动的数值模拟及分析.流体机械,2008,9：30-32
[35]邵蕴秋.Ansys 8.0有限元分析实例导航.北京：中国铁道出版社,2004,30-60
[36]王瑞文.流体力学及海洋数值模拟基于POD技术的降维方法研究：[首都师范大学博士学位论文].北京：北京师范大学,2007,20-24
[37]张勇巍.发电厂高压差阀门气蚀问题的解决方法.中国设备工程,2006,S1：1
[38]顾永泉.机械密封比压选用原则.石油化工设备.2000,29(2),25-36