超临界汽轮机转子热—流耦合问题的数值分析
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摘要
随着火电机组参数的不断提高,汽轮机安全性问题变得日益突出,必须采用各种手段保证机组安全运行,因此,准确预测汽轮机设备寿命,进行合理的寿命管理对延长机组运行寿命、保证机组安全可靠运行具有十分重要的意义。利用已经发展成熟的CFD技术对汽轮机内部流动与换热特性进行研究,可以得到机组启停机等多种工况下通流部分详细温度、压力、速度等参数,对准确进行汽轮机寿命评价具有重要的现实意义。
本文研究了采用CFD软件求解热-流耦合问题的数值计算方法,分析了数值网格尤其是边界层网格对计算结果的影响,必须在保证计算准确性的前提下尽可能减少计算网格的数目,以使在现有计算机硬件条件下和课题预期时间内完成计算任务。另外,通过对两种经典热-流耦合问题的数值计算,得出了使用FLUENT进行热-流耦合问题的一般数值方法,并结合超临界压力水蒸气环境下的流动、换热特性,对使用FLUENT进行热-流耦合数值计算的方法进行探讨和研究。
在上述研究的基础上,本文采用数值计算和理论计算的方法研究了高压缸内汽封的流动特性和泄漏量,并结合汽轮机变工况热力计算,得到变工况下汽轮机高压各级的压力、流量和温度等参数,作为高压缸热-流耦合计算的进出口及其它相应边界的边界条件。最终以某600MW超临界参数汽轮机为研究对象,通过对高压缸内部结构的简化,尤其是对压力级动叶、静叶结构的合理简化建立其几何模型,然后对高压缸内进行热-流耦合数值计算,得到了额定工况及变工况下转子表面温度以及蒸汽与高压缸内缸、转子之间的换热情况,为采用有限元法进行转子热应力分析提供温度边界条件。
本文通过对热-流耦合问题计算的数值方法的研究,得到了使用CFD软件进行超临界参数下热-流耦合问题计算的一般方法,并采用这种方法对某600MW汽轮机高压缸内额定工况和变工况下的流动与换热情况,尤其是转子表面的温度场分布进行计算和分析,是进行转子寿命评价的基础。
With the continuous improvement of thermal power units’parameters, the security issues of steam turbine have become increasingly prominent, and a variety of means must be used to ensure the safe operation of generating units. Therefore, accurately service life prediction and reasonable life management of steam turbine equipment are of great significance to extend life span and ensure safe and reliable operation of the unit. Using the developed CFD technology to research the aerodynamic performance in the steam turbine can get the detailed parameters when the turbine starts and shuts down and other conditions,
which is of practical significance to the life assessment of steam turbine. This paper studies the numerical method of heat and flow coupling and analyzes the impact of numerical grid, especially the boundary layer grid on the results, so the number of computational grid must be coordinated with the computing time and computer capacity. In addition, through the numerical analysis of two classic problems of coupling of heat transfer and flow, and combing the flow and heat transfer characters of supercritical steam, the general numerical method of using the FLUENT software to solve the coupling problem under supercritical pressure was obtained.
On the basis of the above, the paper take the numerical and theoretical methods to calculate the seal leakage and the flow characteristics of the high-pressure cylinder, and combined with variable conditions thermal calculation, pressure and temperature in different conditions of the high-pressure cylinder are got as the boundary conditions of the calculation of turbine. And then, a 600MW supercritical steam turbine was taken as the research object. The geometric modeling was created through the reasonable simplification of the internal structure of high-pressure cylinder, especially for the simplification of the pressure-level blade. Finally the flow and heat transfer in the high pressure cylinder was calculated with the FLUENT software and the temperature of rotor surface and the heat exchange between high pressure steam and the cylinder were obtained, which provide the temperature boundary conditions to thermal stress analysis using the finite element method. Based on the research of numerical method of coupling calculation of flow and heat transfer, a general method to calculate and analyze the problem of flow and heat transfer coupling was obtained by using the CFD software, and then the high pressure cylinder of a 600MW steam turbine was calculated in variable conditions and the flow and heat transfer conditions were showed clearly, especially the rotor surface temperature distribution which is the basis for evaluation of the rotor life.
本文研究了采用CFD软件求解热-流耦合问题的数值计算方法,分析了数值网格尤其是边界层网格对计算结果的影响,必须在保证计算准确性的前提下尽可能减少计算网格的数目,以使在现有计算机硬件条件下和课题预期时间内完成计算任务。另外,通过对两种经典热-流耦合问题的数值计算,得出了使用FLUENT进行热-流耦合问题的一般数值方法,并结合超临界压力水蒸气环境下的流动、换热特性,对使用FLUENT进行热-流耦合数值计算的方法进行探讨和研究。
在上述研究的基础上,本文采用数值计算和理论计算的方法研究了高压缸内汽封的流动特性和泄漏量,并结合汽轮机变工况热力计算,得到变工况下汽轮机高压各级的压力、流量和温度等参数,作为高压缸热-流耦合计算的进出口及其它相应边界的边界条件。最终以某600MW超临界参数汽轮机为研究对象,通过对高压缸内部结构的简化,尤其是对压力级动叶、静叶结构的合理简化建立其几何模型,然后对高压缸内进行热-流耦合数值计算,得到了额定工况及变工况下转子表面温度以及蒸汽与高压缸内缸、转子之间的换热情况,为采用有限元法进行转子热应力分析提供温度边界条件。
本文通过对热-流耦合问题计算的数值方法的研究,得到了使用CFD软件进行超临界参数下热-流耦合问题计算的一般方法,并采用这种方法对某600MW汽轮机高压缸内额定工况和变工况下的流动与换热情况,尤其是转子表面的温度场分布进行计算和分析,是进行转子寿命评价的基础。
With the continuous improvement of thermal power units’parameters, the security issues of steam turbine have become increasingly prominent, and a variety of means must be used to ensure the safe operation of generating units. Therefore, accurately service life prediction and reasonable life management of steam turbine equipment are of great significance to extend life span and ensure safe and reliable operation of the unit. Using the developed CFD technology to research the aerodynamic performance in the steam turbine can get the detailed parameters when the turbine starts and shuts down and other conditions,
which is of practical significance to the life assessment of steam turbine. This paper studies the numerical method of heat and flow coupling and analyzes the impact of numerical grid, especially the boundary layer grid on the results, so the number of computational grid must be coordinated with the computing time and computer capacity. In addition, through the numerical analysis of two classic problems of coupling of heat transfer and flow, and combing the flow and heat transfer characters of supercritical steam, the general numerical method of using the FLUENT software to solve the coupling problem under supercritical pressure was obtained.
On the basis of the above, the paper take the numerical and theoretical methods to calculate the seal leakage and the flow characteristics of the high-pressure cylinder, and combined with variable conditions thermal calculation, pressure and temperature in different conditions of the high-pressure cylinder are got as the boundary conditions of the calculation of turbine. And then, a 600MW supercritical steam turbine was taken as the research object. The geometric modeling was created through the reasonable simplification of the internal structure of high-pressure cylinder, especially for the simplification of the pressure-level blade. Finally the flow and heat transfer in the high pressure cylinder was calculated with the FLUENT software and the temperature of rotor surface and the heat exchange between high pressure steam and the cylinder were obtained, which provide the temperature boundary conditions to thermal stress analysis using the finite element method. Based on the research of numerical method of coupling calculation of flow and heat transfer, a general method to calculate and analyze the problem of flow and heat transfer coupling was obtained by using the CFD software, and then the high pressure cylinder of a 600MW steam turbine was calculated in variable conditions and the flow and heat transfer conditions were showed clearly, especially the rotor surface temperature distribution which is the basis for evaluation of the rotor life.
引文
[1]胡先约,汽轮机寿命管理与调峰中的若干问题.动力工程,1985(01)
[2]张保衡,大容量火电机组寿命管理与调峰运行.1988:水利电力出版社
[3]陈四利等,汽轮机转子温度场和应力场的有限元分析.沈阳工业大学学报,2007(02)
[4]罗娟,胡念苏,祁海涛,汽轮机转子温度场有限元法简化计算模型.热力发电,2004(05)
[5]路义萍等,大型空冷汽轮发电机转子温度场数值模拟.中国电机工程学报,2007(12)
[6]葛晓霞与缨国钧,汽轮机启动过程中转子温度的计算分析.热力发电,1997(05)
[7]戴丽萍,蔡虎与康顺,150MW汽轮机高压缸级内流场的数值模拟.动力工程,2008(05)
[8]樊涛等,基于多块网格技术的排汽缸与低压级组耦合流动分析.汽轮机技术,2007(04)
[9]肖玉广与徐惠坚,汽轮机内湿蒸汽流动特性的数值模拟.汽轮机技术,2010(03)
[10]朱华等,汽轮机启、停过程中汽缸温差的数值计算.动力工程,2001(03)
[11]刘晓锋与陆颂元,迷宫密封转子动特性三维CFD数值的研究.热能动力工程,2006(06)
[12] Seghir-Ouali, S., et al., Convective heat transfer inside a rotating cylinder with an axial air flow. International Journal of Thermal Sciences, 2006. 45(12): p. 1166-1178
[13] Chen. H. and B. Zhang, Theoretical and numerical analysis of convective heat transfer in the rotating helical pipes. International Journal of Heat and Mass Transfer, 2003. 46(25): p. 4899-4909
[14]陶文铨与杨世铭,传热学第三版.1998
[15]陶文铨,数值传热学.1988
[16]张丽芬,采用热流耦合方法对内冷式涡轮叶片换热的计算研究,2006
[17]刘振侠与张丽芬,采用热-流耦合方法对气冷涡轮叶片换热的计算.西北工业大学学报,2007(02)
[18] Perelman and T. L., On Conjugated Problem of Heat Transfer. Heat Mass Transfer, 1961: p. 295-300
[19] Luikov and A.V. Aleksashenko, Analytical Methods of Solution of Conjugated Problems in Convective Heat Transfer. Heat Mass Transfer, 1974: p. 1047-1056
[20]李永红,高温气态燃料流量调节阀的多场耦合热力学特性研究,2008
[21] Bohn, D., J. Ren and K. Kusterer, Investigation of the steam-cooled blade in a steam turbine cascade. JOURNAL OF AEROSPACE POWER , 2007. 22(5)
[22] Dorney, D., B. Ng and A. Al-Habbas, Numerical simulations of hot streak migration in a 1-1/2 stage turbine. Aerospace Sciences, 1995
[23]郑民牛,超超临界1000MW锅炉选型的几个关键要点.动力工程,2006(02)
[24]王建国等,垂直上升内螺纹管内超临界压力水的传热特性研究.工程热物理学报,2009. 30(3):第423-427页
[25]王为术等,垂直上升内螺纹管中超超临界压力水的传热特性研究.核动力工程,2007. 28(3):第43-46,60页
[26]朱奇,超超临界百万千瓦汽轮机主调阀流场非稳态数值研究,2010,上海交通大学
[27] Fluent, I., Fluent 6.0 User's Guide. 2001
[28]齐鄂荣与曾玉红,工程流体力学.2005,武汉:武汉大学出版社
[29]赵玉新,Fluent中文全教程,2004:国防科技大学
[30]陶文铨,杨世铭,传热学第三版.1998
[31] Hall, W.B., Heat transfer near the critical point. Advances in heat transfer. Vol. 7. 1971, London: Academic Press Inc
[32]康松,杨建明,胥建群,汽轮机原理.2000:中国电力出版社.65-73
[33]王运民,汽轮机变工况时各监视段压力与温度的定量计算.汽轮机技术,2007(06)
[34] C., P., P.U. S. and S.N. V., Analysis of laminar flow and heat transfer between a stationary and a rotating disk. 1985. 23: p. 1666-1667
[35] Ameri, A.A., E. Steinthorsson and D.L. Rigby, Effect of squealer tip on rotor heat transfer and efficiency. ASME Journal of Turbomachinery, 1998. 120(4): p. 753-759
[36] Roy, G. and C. Nguyen, Numerical investigation of laminar flow and heat transfer in a radial flow cooling system with the use of nanofluids. Superlattices and Microstructures, 2004. 35(3-6): p. 497-511
[37] Imlay, S.T., M. Soetrisno and D.W. Roberts, Three-dimensional simulations of hot streak clocking in a stage turbine. 1996
[38] Schlichting Hermann. Boundary Layer Theory. 7th edition. NY. McGraw Hill. 1979
[39] Dorney DJ, Ng BC, Al-Habbas A. Numerical simulations of hot streak migration in a 1-1/2 stage turbine. Aerospace Sciences. 1995
[40] Saniei N., Z. X. Yuan, Johnson T. Heat Transfer from a Stationary Disk Situated near a Secondary Rotating Disk. 8th AIAA/ASME Joint Thermophysics and Heat Transfer Conference. 2002. 22-24
[41]黄唐,毛国良,姜贵庆,周伟江.二维流场、热、结构一体化数值模拟.空气动力学学报. 2000. (01)
[42]刘中良,马重芳.层流管流耦合换热对流体热边界条件的影响.北京工业大学学报. 2002. (01)
[43]黄山鹤,黄树红,王坤.分析强制冷却对200 MW汽轮机高压转子寿命损耗的影响.广东电力. 2005. 18(3). 16-20,59
[44] Perng Chin-Yuan, Street Robert L. Three-dimensional unsteady flow simulations: Alternative strategies for a volume-averaged calculation. International Journal for Numerical Methods in Fluids. 1989. 9(3). 341-362
[45]王建梅,蔡锴,卫国涛,阚伟民,黄庭辉.调峰汽轮机转子热应力及寿命损耗在线监测系统.汽轮机技术. 2001. 43(5). 298-300
[46]江宁,曹祖庆.考虑到材料温度特性的汽机转子疲劳寿命计算.东南大学学报(自然科学版). 1999. 29(4). 154
[47]张为荣,王强.汽封流场及泄漏特性的数值模拟分析.汽轮机技术. 2008. (02)
[48]孙伟.调峰运行的燃气轮机联合循环汽轮机转子热应力和寿命损耗分析.动力工程. 2003. 23(2). 2266-2269
[49] Imlay Scott T., Soetrisno Moeljo, Roberts Donald W. Three-dimensional simulations of hot streak clocking in a stage turbine. 1996
[50] CHANG SHYY WOEI, YANG TSUN LIRNG, Tong-Miin LIOU, FANG HONG GUO. Heat transfer in rotating scale-roughened trapezoidal duct at high rotation numbers. 2009. 29(8). 1682-1693
[2]张保衡,大容量火电机组寿命管理与调峰运行.1988:水利电力出版社
[3]陈四利等,汽轮机转子温度场和应力场的有限元分析.沈阳工业大学学报,2007(02)
[4]罗娟,胡念苏,祁海涛,汽轮机转子温度场有限元法简化计算模型.热力发电,2004(05)
[5]路义萍等,大型空冷汽轮发电机转子温度场数值模拟.中国电机工程学报,2007(12)
[6]葛晓霞与缨国钧,汽轮机启动过程中转子温度的计算分析.热力发电,1997(05)
[7]戴丽萍,蔡虎与康顺,150MW汽轮机高压缸级内流场的数值模拟.动力工程,2008(05)
[8]樊涛等,基于多块网格技术的排汽缸与低压级组耦合流动分析.汽轮机技术,2007(04)
[9]肖玉广与徐惠坚,汽轮机内湿蒸汽流动特性的数值模拟.汽轮机技术,2010(03)
[10]朱华等,汽轮机启、停过程中汽缸温差的数值计算.动力工程,2001(03)
[11]刘晓锋与陆颂元,迷宫密封转子动特性三维CFD数值的研究.热能动力工程,2006(06)
[12] Seghir-Ouali, S., et al., Convective heat transfer inside a rotating cylinder with an axial air flow. International Journal of Thermal Sciences, 2006. 45(12): p. 1166-1178
[13] Chen. H. and B. Zhang, Theoretical and numerical analysis of convective heat transfer in the rotating helical pipes. International Journal of Heat and Mass Transfer, 2003. 46(25): p. 4899-4909
[14]陶文铨与杨世铭,传热学第三版.1998
[15]陶文铨,数值传热学.1988
[16]张丽芬,采用热流耦合方法对内冷式涡轮叶片换热的计算研究,2006
[17]刘振侠与张丽芬,采用热-流耦合方法对气冷涡轮叶片换热的计算.西北工业大学学报,2007(02)
[18] Perelman and T. L., On Conjugated Problem of Heat Transfer. Heat Mass Transfer, 1961: p. 295-300
[19] Luikov and A.V. Aleksashenko, Analytical Methods of Solution of Conjugated Problems in Convective Heat Transfer. Heat Mass Transfer, 1974: p. 1047-1056
[20]李永红,高温气态燃料流量调节阀的多场耦合热力学特性研究,2008
[21] Bohn, D., J. Ren and K. Kusterer, Investigation of the steam-cooled blade in a steam turbine cascade. JOURNAL OF AEROSPACE POWER , 2007. 22(5)
[22] Dorney, D., B. Ng and A. Al-Habbas, Numerical simulations of hot streak migration in a 1-1/2 stage turbine. Aerospace Sciences, 1995
[23]郑民牛,超超临界1000MW锅炉选型的几个关键要点.动力工程,2006(02)
[24]王建国等,垂直上升内螺纹管内超临界压力水的传热特性研究.工程热物理学报,2009. 30(3):第423-427页
[25]王为术等,垂直上升内螺纹管中超超临界压力水的传热特性研究.核动力工程,2007. 28(3):第43-46,60页
[26]朱奇,超超临界百万千瓦汽轮机主调阀流场非稳态数值研究,2010,上海交通大学
[27] Fluent, I., Fluent 6.0 User's Guide. 2001
[28]齐鄂荣与曾玉红,工程流体力学.2005,武汉:武汉大学出版社
[29]赵玉新,Fluent中文全教程,2004:国防科技大学
[30]陶文铨,杨世铭,传热学第三版.1998
[31] Hall, W.B., Heat transfer near the critical point. Advances in heat transfer. Vol. 7. 1971, London: Academic Press Inc
[32]康松,杨建明,胥建群,汽轮机原理.2000:中国电力出版社.65-73
[33]王运民,汽轮机变工况时各监视段压力与温度的定量计算.汽轮机技术,2007(06)
[34] C., P., P.U. S. and S.N. V., Analysis of laminar flow and heat transfer between a stationary and a rotating disk. 1985. 23: p. 1666-1667
[35] Ameri, A.A., E. Steinthorsson and D.L. Rigby, Effect of squealer tip on rotor heat transfer and efficiency. ASME Journal of Turbomachinery, 1998. 120(4): p. 753-759
[36] Roy, G. and C. Nguyen, Numerical investigation of laminar flow and heat transfer in a radial flow cooling system with the use of nanofluids. Superlattices and Microstructures, 2004. 35(3-6): p. 497-511
[37] Imlay, S.T., M. Soetrisno and D.W. Roberts, Three-dimensional simulations of hot streak clocking in a stage turbine. 1996
[38] Schlichting Hermann. Boundary Layer Theory. 7th edition. NY. McGraw Hill. 1979
[39] Dorney DJ, Ng BC, Al-Habbas A. Numerical simulations of hot streak migration in a 1-1/2 stage turbine. Aerospace Sciences. 1995
[40] Saniei N., Z. X. Yuan, Johnson T. Heat Transfer from a Stationary Disk Situated near a Secondary Rotating Disk. 8th AIAA/ASME Joint Thermophysics and Heat Transfer Conference. 2002. 22-24
[41]黄唐,毛国良,姜贵庆,周伟江.二维流场、热、结构一体化数值模拟.空气动力学学报. 2000. (01)
[42]刘中良,马重芳.层流管流耦合换热对流体热边界条件的影响.北京工业大学学报. 2002. (01)
[43]黄山鹤,黄树红,王坤.分析强制冷却对200 MW汽轮机高压转子寿命损耗的影响.广东电力. 2005. 18(3). 16-20,59
[44] Perng Chin-Yuan, Street Robert L. Three-dimensional unsteady flow simulations: Alternative strategies for a volume-averaged calculation. International Journal for Numerical Methods in Fluids. 1989. 9(3). 341-362
[45]王建梅,蔡锴,卫国涛,阚伟民,黄庭辉.调峰汽轮机转子热应力及寿命损耗在线监测系统.汽轮机技术. 2001. 43(5). 298-300
[46]江宁,曹祖庆.考虑到材料温度特性的汽机转子疲劳寿命计算.东南大学学报(自然科学版). 1999. 29(4). 154
[47]张为荣,王强.汽封流场及泄漏特性的数值模拟分析.汽轮机技术. 2008. (02)
[48]孙伟.调峰运行的燃气轮机联合循环汽轮机转子热应力和寿命损耗分析.动力工程. 2003. 23(2). 2266-2269
[49] Imlay Scott T., Soetrisno Moeljo, Roberts Donald W. Three-dimensional simulations of hot streak clocking in a stage turbine. 1996
[50] CHANG SHYY WOEI, YANG TSUN LIRNG, Tong-Miin LIOU, FANG HONG GUO. Heat transfer in rotating scale-roughened trapezoidal duct at high rotation numbers. 2009. 29(8). 1682-1693