超超临界汽轮机高温叶片强度分析
摘要
超超临界技术的发展,使得汽轮机的强度问题日益突出,如何准确地评估汽轮机部件的高温强度,也是目前高参数汽轮机设计和考核中的一大难题。叶片是汽轮机的核心部件之一,其安全可靠性直接影响汽轮发电机组的运行安全。针对超超临界机组大容量,高参数的特性,动叶片叶根以及转子轮槽均承受极大的应力负荷,因此,在设计阶段对汽轮机高温叶片与轮缘进行全面的强度分析和评估十分有必要性。
本课题针对超超临界机组高温环境下工作的叶片的安全性需要,采用了目前在工程领域应用广泛的CFD和FEA计算理论与方法,对汽轮机叶片与轮缘进行全面的强度分析和评估。以实际汽轮机叶片的热应力求解过程为例,从其CFD求解叶型表面对流换热系数开始,说明了采用插值程序将CFD结果插值到有限元模型的过程以及该叶片在启动过程中的温度场和应力场求解方法。给出了汽轮机叶片的热应力分析规范,包括计算状态选取、计算参数的设置、计算结果的处理和评定。简单介绍了蠕变本构模型的选取、蠕变参数的拟合方法,并说明了蠕变应力的分析过程。参考相关应力评定标准,初步建立汽轮机叶片蠕变应力和变形评定标准及分析规范,提出可供设计人员参考的叶片强度评定准则。
本课题的研究有利于解决超超临界机组设计中的瓶颈问题,对超超临界汽轮机现役机组的运行以及自主开发新型高参数、大容量机组的设计奠定坚实的基础、取得宝贵的借鉴经验。
With the development of ultra supercritical steam turbine technologies, strength of steam turbine is drawing more and more attentions. Nowadays, how to accurately evaluate strength under elevated temperature is a nodus in high-parameter steam-turbine design and verification. The blade is one of the most important parts of steam turbine. Operation safety of steam turbine-generator units is closely related to the reliability of rotating blades. The root & groove of high temperature blade bear the high power load for ultra supercritical (USC) unit which has high steam conditions. Hence, the properly analysis and evaluation of the blade strength during design is very necessary.
For the safety demand, the paper analyzes and evaluates the strength of high temperature blade root & groove for USC turbine using the CFD & EFA method which is widely applied in engineering field. Take example for saluting the heat stress of an actual blade. Start with the solution of convective heat exchange coefficient using CFD method. The paper shows the process of interpolating CFD result to the FEA model using interpolating program and the solution method of the temperature field and stress field in turbine start-up. It offers the analysis procedure of heat stress, including the choice of calculating state, the setup of calculating parameter, the dispose and evaluate of calculating result. The choice of creep constitutive model, fitting method of creep parameter and the analysis process of creep stress are brief introduced. The evaluate criterion of blade strength including heat stress and creep stress analysis is offered to designer for reference.
This analytical method has reference meaning in solving the design bottleneck and analyzing strength of turbine’s high temperature blades.
本课题针对超超临界机组高温环境下工作的叶片的安全性需要,采用了目前在工程领域应用广泛的CFD和FEA计算理论与方法,对汽轮机叶片与轮缘进行全面的强度分析和评估。以实际汽轮机叶片的热应力求解过程为例,从其CFD求解叶型表面对流换热系数开始,说明了采用插值程序将CFD结果插值到有限元模型的过程以及该叶片在启动过程中的温度场和应力场求解方法。给出了汽轮机叶片的热应力分析规范,包括计算状态选取、计算参数的设置、计算结果的处理和评定。简单介绍了蠕变本构模型的选取、蠕变参数的拟合方法,并说明了蠕变应力的分析过程。参考相关应力评定标准,初步建立汽轮机叶片蠕变应力和变形评定标准及分析规范,提出可供设计人员参考的叶片强度评定准则。
本课题的研究有利于解决超超临界机组设计中的瓶颈问题,对超超临界汽轮机现役机组的运行以及自主开发新型高参数、大容量机组的设计奠定坚实的基础、取得宝贵的借鉴经验。
With the development of ultra supercritical steam turbine technologies, strength of steam turbine is drawing more and more attentions. Nowadays, how to accurately evaluate strength under elevated temperature is a nodus in high-parameter steam-turbine design and verification. The blade is one of the most important parts of steam turbine. Operation safety of steam turbine-generator units is closely related to the reliability of rotating blades. The root & groove of high temperature blade bear the high power load for ultra supercritical (USC) unit which has high steam conditions. Hence, the properly analysis and evaluation of the blade strength during design is very necessary.
For the safety demand, the paper analyzes and evaluates the strength of high temperature blade root & groove for USC turbine using the CFD & EFA method which is widely applied in engineering field. Take example for saluting the heat stress of an actual blade. Start with the solution of convective heat exchange coefficient using CFD method. The paper shows the process of interpolating CFD result to the FEA model using interpolating program and the solution method of the temperature field and stress field in turbine start-up. It offers the analysis procedure of heat stress, including the choice of calculating state, the setup of calculating parameter, the dispose and evaluate of calculating result. The choice of creep constitutive model, fitting method of creep parameter and the analysis process of creep stress are brief introduced. The evaluate criterion of blade strength including heat stress and creep stress analysis is offered to designer for reference.
This analytical method has reference meaning in solving the design bottleneck and analyzing strength of turbine’s high temperature blades.
引文
[1] R. Viswanathan. Damage Mechanisms and life assessment of High-Temperature Components [M]. ASM International. 1989.
[2]周顺深,火电厂高温部件剩余寿命评估[M],北京:中国电力出版社, 2006
[3]吕智强,韩万金,24.2MPa-566℃/566℃超临界汽轮机材料选择特点[J],汽轮机技术,2004, 46(03):164-166
[4]史进渊,杨宇等.电站汽轮机研制与生产的可靠性技术研究[J].动力工程. 2005,25(1):7-12
[5]安江英,张保衡,关于汽轮机转子寿命预测中的若干问题[J],华北电力大学学报,1996,23(4):68-73
[6]钟启新,张家琛等,汽轮机调节[M],华中工学院出版社,1983
[7]张保衡,大容量火电机组寿命管理与调峰运行[M],北京:水利电力出版社,1988
[8]荆建平,孟光等,汽轮机转子疲劳–蠕变损伤的非线性损伤力学分析[J],汽轮机技术,2003,23(09):167-172.
[9]张俊善,材料的高温断裂与变形[M],北京:科学出版社,2007
[10]林富生,超超临界参数机组材料国产化对策[J],动力工程,2004,24(1):211-317
[11] Sabada K, Kubo K etc. Contribution of coarsening of MX carbonitrides to creep strength degradation in high chromium ferritic steel[J]. Materials Science and Technology. 2003, 19(2):732-740
[12]毛雪平,王罡等,超超临界机组汽轮机材料发展状况[J],现代电力,2005, 2(1):69-75
[13] Lemaitre J. Application of damage concepts to predict creep-fatigue failures[J]. Transaction of ASME, Journal of Engineering Material and Technology. 1979(101):284-292
[14] Lemaitre J. A Continuum damage mechanics model for ductile fracture[J]. Transaction of ASME, Journal of Engineering Material and Technology. 1985(107):83-89
[15]王坤,大型汽轮机寿命问题研究[D],武汉:华中科技大学,2004
[16]史进渊,杨宇等,大型汽轮机部件低周疲劳安全寿命的设计和评定[J],应用力学学报, 2004.21(3):153-156,14
[17]嵇国金,彭颖红,金属体积成形中的韧性损伤准则[J],中国有色金属学报,1999,9(01):35-38
[18]荆建平,孙毅等,非线性连续损伤模型在汽轮机转子低周疲劳分析中的应用[J],中国电机工程学报.2001.21(10):28-32
[19] Turner, M. J. , Clough, R. W. , Martin H. C. ,Topp L. C. , Stiffness and Deflection Analysis of Complex Structures J. Aero. Sci. 1956, 23:805-823
[20] Clough, R. W. , The Finite Element Method in Plane Stress Analysis. Proc. 2nd ASME Conference on Electronic Computation, Pittsburgh, Pa. , Sept. 1960
[21] Besseling, J. F. The Complete Analogy between the Matrix Equations and the Continuous Field Equations of Structural Analysis. International Symposium on Analogue and Digital Techniques Applied to Aeronautics, Liege, Belgium, 1963
[22] Melosh, R. J. , Basis for the Derivation of Matrics for the Direct Stiffness Method. AIAAJ. 1963, 1:1631-1637.Jones, R. E. , A Generalization of the Direct Stiffness Method of Structural Analysis. AIAAJ. 1964, 2:821-826
[23] S. Timoshenkoand, S. Woinowsky-Krieger, Theory of Plates and Shells, McGraw-Hill, New York. 1959
[24]史进渊,孙庆等,大型汽轮机部件蠕变寿命的设计和评估[J],中国电机工程学报,2002.22(3):103-107
[25]朱彦伟,朱惠人,不同湍流模型对叶片表面换热系数结果的影响,机械设计与制造,2008,p46-p48
[26]史进渊,邓志成,杨宇,龚干文,大功率汽轮机叶轮轮缘传热系数的研究,动力工程,2007,vol27(2):p153-p156
[27]史进渊,杨宇,邓志成,张兆鹤,超临界和超超临界汽轮机汽缸传热系数的研究,动力工程,2006,vol26(1):p1-p5
[2]周顺深,火电厂高温部件剩余寿命评估[M],北京:中国电力出版社, 2006
[3]吕智强,韩万金,24.2MPa-566℃/566℃超临界汽轮机材料选择特点[J],汽轮机技术,2004, 46(03):164-166
[4]史进渊,杨宇等.电站汽轮机研制与生产的可靠性技术研究[J].动力工程. 2005,25(1):7-12
[5]安江英,张保衡,关于汽轮机转子寿命预测中的若干问题[J],华北电力大学学报,1996,23(4):68-73
[6]钟启新,张家琛等,汽轮机调节[M],华中工学院出版社,1983
[7]张保衡,大容量火电机组寿命管理与调峰运行[M],北京:水利电力出版社,1988
[8]荆建平,孟光等,汽轮机转子疲劳–蠕变损伤的非线性损伤力学分析[J],汽轮机技术,2003,23(09):167-172.
[9]张俊善,材料的高温断裂与变形[M],北京:科学出版社,2007
[10]林富生,超超临界参数机组材料国产化对策[J],动力工程,2004,24(1):211-317
[11] Sabada K, Kubo K etc. Contribution of coarsening of MX carbonitrides to creep strength degradation in high chromium ferritic steel[J]. Materials Science and Technology. 2003, 19(2):732-740
[12]毛雪平,王罡等,超超临界机组汽轮机材料发展状况[J],现代电力,2005, 2(1):69-75
[13] Lemaitre J. Application of damage concepts to predict creep-fatigue failures[J]. Transaction of ASME, Journal of Engineering Material and Technology. 1979(101):284-292
[14] Lemaitre J. A Continuum damage mechanics model for ductile fracture[J]. Transaction of ASME, Journal of Engineering Material and Technology. 1985(107):83-89
[15]王坤,大型汽轮机寿命问题研究[D],武汉:华中科技大学,2004
[16]史进渊,杨宇等,大型汽轮机部件低周疲劳安全寿命的设计和评定[J],应用力学学报, 2004.21(3):153-156,14
[17]嵇国金,彭颖红,金属体积成形中的韧性损伤准则[J],中国有色金属学报,1999,9(01):35-38
[18]荆建平,孙毅等,非线性连续损伤模型在汽轮机转子低周疲劳分析中的应用[J],中国电机工程学报.2001.21(10):28-32
[19] Turner, M. J. , Clough, R. W. , Martin H. C. ,Topp L. C. , Stiffness and Deflection Analysis of Complex Structures J. Aero. Sci. 1956, 23:805-823
[20] Clough, R. W. , The Finite Element Method in Plane Stress Analysis. Proc. 2nd ASME Conference on Electronic Computation, Pittsburgh, Pa. , Sept. 1960
[21] Besseling, J. F. The Complete Analogy between the Matrix Equations and the Continuous Field Equations of Structural Analysis. International Symposium on Analogue and Digital Techniques Applied to Aeronautics, Liege, Belgium, 1963
[22] Melosh, R. J. , Basis for the Derivation of Matrics for the Direct Stiffness Method. AIAAJ. 1963, 1:1631-1637.Jones, R. E. , A Generalization of the Direct Stiffness Method of Structural Analysis. AIAAJ. 1964, 2:821-826
[23] S. Timoshenkoand, S. Woinowsky-Krieger, Theory of Plates and Shells, McGraw-Hill, New York. 1959
[24]史进渊,孙庆等,大型汽轮机部件蠕变寿命的设计和评估[J],中国电机工程学报,2002.22(3):103-107
[25]朱彦伟,朱惠人,不同湍流模型对叶片表面换热系数结果的影响,机械设计与制造,2008,p46-p48
[26]史进渊,邓志成,杨宇,龚干文,大功率汽轮机叶轮轮缘传热系数的研究,动力工程,2007,vol27(2):p153-p156
[27]史进渊,杨宇,邓志成,张兆鹤,超临界和超超临界汽轮机汽缸传热系数的研究,动力工程,2006,vol26(1):p1-p5