大型LNG储罐在静力及动力工况下的有限元分析
摘要
近年来,在国外技术的支持下,我国多个地区建设了多座大型LNG全容式储罐。同时,在从事储罐建设事业的人员和科研人员的共同努力下,国内在大型LNG储罐的建造和设计技术上也取得了很大的进步,但在很多方面仍然存在技术上的问题,不能完全实现LNG储罐国产化,这就需要更多的后来人员在关键技术上的关注和研究分析。
本文以大型LNG储罐预应力钢筋混凝土外罐壁为研究对象,所做的主要工作如下:
1.采用ANSYS有限元软件建立了16万m3容积的大型LNG储罐外罐的有限元三维模型。
2.参考国内外荷载规范及工程经验资料,确定了各种荷载的取值。同时,采用规范中提出的极限状态设计法,给出了正常荷载工况和偶然荷载工况下各荷载组合公式,并明确了可变荷载组合系数及各荷载偏系数(中国规范称为分项系数)的取值。
3.对LNG储罐外罐在不同工况下进行了有限元计算和分析,得出各种荷载组合工况作用下LNG储罐外罐水平截面和竖直截面的内力沿着高度的变化规律,并对各项结果进行了对比分析。
通过对ANSYS软件计算出的结果的分析发现:LNG储罐在各工况下,罐体顶部和底部所受的内力最大,且拉应力值超出了混凝土抗拉强度设计值,相应部位属于带裂缝工作状态;在荷载(荷载效应)组合中,欧洲规范能适用于荷载组合及荷载效应组合,中国规范只适用荷载效应组合,中国规范的得出的结果较欧洲规范更加偏于安全;在欧洲规范组合中,工况2和工况4在设计中占主导地位,即对罐体产生的内力最为不利。
In recent years, with the support of foreign technology, many large-scale full containment storage tanks of LNG were built in various parts of China. Meanwhile, with the joint efforts of researchers and the persons engaged in construction of the tanks, domestic large-scale LNG storage tank in this field of construction and design technology have made great progress, but there are still so many technical problems not being solved in many ways that localization of LNG storage tanks is not realized completely, so more concern and technical research and analysis are required.
In this paper, the large-scale outer tank of prestressed reinforced concrete is as the object of research, the main work is as follows:
Firstly, the ANSYS finite element software was used, the 3D finite element model of large volume of 160 000 m3 LNG storage tank of outer wall was established.
Secondly, based on domestic/international load standards and the data of engineering experiences, the value of the various loads were determined. At the same time, the limit state design method proposed in relevant codes was adopted, the action or action effect combination formula under the normal and accidental action conditions were given, and the combination coefficients and the partial factor values of the variable load were listed clearly. Thirdly, the outer tank in different cases was caculated and analysed through the finite element software. Under the cases of the various action or action effect combination, the internal forces (axis force, shear force, bending moment) of the horizontal sections and vertical cross-section of the outer tank along the height variation were got, and the results were analyzed.
Through the calculation of using ANSYS software and the analysis of results, some conclusions can be drawn. In various cases, the top and bottom of the tank suffer the maximum of the forces, and the tensile stress exceeds the tensile strength of concrete design value, with corresponding parts are cracking in working condition; In action or action effect combination, the European codes can be applied to the load combinations and load effect combination, but the Chinese codes only can be applied to action effect combination, the calculation result of Chinese codes is more safety than the European codes; Just considering European codes, case 2 and case 4 in the design conditions dominate, at that case, the most negative forces in the outer tank can be generated.
本文以大型LNG储罐预应力钢筋混凝土外罐壁为研究对象,所做的主要工作如下:
1.采用ANSYS有限元软件建立了16万m3容积的大型LNG储罐外罐的有限元三维模型。
2.参考国内外荷载规范及工程经验资料,确定了各种荷载的取值。同时,采用规范中提出的极限状态设计法,给出了正常荷载工况和偶然荷载工况下各荷载组合公式,并明确了可变荷载组合系数及各荷载偏系数(中国规范称为分项系数)的取值。
3.对LNG储罐外罐在不同工况下进行了有限元计算和分析,得出各种荷载组合工况作用下LNG储罐外罐水平截面和竖直截面的内力沿着高度的变化规律,并对各项结果进行了对比分析。
通过对ANSYS软件计算出的结果的分析发现:LNG储罐在各工况下,罐体顶部和底部所受的内力最大,且拉应力值超出了混凝土抗拉强度设计值,相应部位属于带裂缝工作状态;在荷载(荷载效应)组合中,欧洲规范能适用于荷载组合及荷载效应组合,中国规范只适用荷载效应组合,中国规范的得出的结果较欧洲规范更加偏于安全;在欧洲规范组合中,工况2和工况4在设计中占主导地位,即对罐体产生的内力最为不利。
In recent years, with the support of foreign technology, many large-scale full containment storage tanks of LNG were built in various parts of China. Meanwhile, with the joint efforts of researchers and the persons engaged in construction of the tanks, domestic large-scale LNG storage tank in this field of construction and design technology have made great progress, but there are still so many technical problems not being solved in many ways that localization of LNG storage tanks is not realized completely, so more concern and technical research and analysis are required.
In this paper, the large-scale outer tank of prestressed reinforced concrete is as the object of research, the main work is as follows:
Firstly, the ANSYS finite element software was used, the 3D finite element model of large volume of 160 000 m3 LNG storage tank of outer wall was established.
Secondly, based on domestic/international load standards and the data of engineering experiences, the value of the various loads were determined. At the same time, the limit state design method proposed in relevant codes was adopted, the action or action effect combination formula under the normal and accidental action conditions were given, and the combination coefficients and the partial factor values of the variable load were listed clearly. Thirdly, the outer tank in different cases was caculated and analysed through the finite element software. Under the cases of the various action or action effect combination, the internal forces (axis force, shear force, bending moment) of the horizontal sections and vertical cross-section of the outer tank along the height variation were got, and the results were analyzed.
Through the calculation of using ANSYS software and the analysis of results, some conclusions can be drawn. In various cases, the top and bottom of the tank suffer the maximum of the forces, and the tensile stress exceeds the tensile strength of concrete design value, with corresponding parts are cracking in working condition; In action or action effect combination, the European codes can be applied to the load combinations and load effect combination, but the Chinese codes only can be applied to action effect combination, the calculation result of Chinese codes is more safety than the European codes; Just considering European codes, case 2 and case 4 in the design conditions dominate, at that case, the most negative forces in the outer tank can be generated.
引文
[1]顾安忠.迎向“十二五”中国LNG的新发展[J] .天然气工业,2011(6),31(6):1-11.
[2]黄群,夏芳.LNG储罐国产化的可行性[J].天然气工业,2010(7):80-82.王振良,李臻.
[3]国内外大型液化天然气储罐发展状况[J].河南化工,2010,27(5):2-3.
[4]马德萍.隔震LNG储罐的地震反应分析[D].哈尔滨市:哈尔滨工业大学,2007(7).
[5]张云峰,张彬,岳文彤.内罐泄漏条件下LNG混凝土储罐预应力外墙模态分析[J].大庆石油学院学报,2008(12),32(6):86-89.
[6]王伟玲.大型LNG预应力储罐静力荷载下受力性能研究[D].大庆市:大庆石油学院,2009(3).
[7]杨涛.LNG储罐壳体抗风与抗震力学性能研究[D].大庆市:大庆石油学院,2010(3).
[8]柳山.液化天然气(LNG)全容储罐结构和性能研究[D].广州市:华南理工大学,2009(12).
[9]王琪.大型LNG储罐在内罐泄漏及内压工况下的有限元分析[D].天津:天津大学建筑工程学院,2010(6):1-3.
[10]吕娜娜.大型LNG储罐有限元静力分析[D].天津:天津大学建筑工程学院,2010(6):1-16.
[11]杜帅.大型LNG储罐在不同预应力筋张拉阶段的有限元分析[D].天津:天津大学建筑工程学院,2010(6):1-4.
[12]李思.全容式LNG储罐的地震响应分析[D].天津:天津大学建筑工程学院,2010(5).
[13]孙建刚,崔利富,张营.全容式LNG储罐地震响应数值模拟研究[J].2010中国(北京)国际建筑科技大会论文集,2010:225-230.
[14]李文,张彬.内罐泄露条件下LNG储罐预应力混凝土外墙时程分析[J].科学技术与工程,2010(5),10(14):3349-3354.
[15]郭揆常.液化天然气(LNG)应用与安全[M].北京:中国石化出版社,2008.
[16]张抗.世界液化天然气发展状况与展望[J].当代石油石化,2006,14(4):31-34.
[17]杨永谦,肖金生.实用有限元分析技术—ANSYS专题与技巧[M].北京:机械工业出版社,2010(10) .
[18]王新敏.ANSYS工程结构数值分析[M].北京:人民交通出版社,2007(10).
[19]龚曙光,谢桂兰.ANSYS操作命令与参数化编程[M].北京:机械工业出版社,2004(4).
[20]尚晓江,邱峰,赵海峰,李文颖.ANSYS结构有限元高级分析方法与范例应用[M].北京:中国水利水电出版社,2006.
[21]吴浩,卢云祥.上海LNG储罐外罐建造方案研究[J].2008,8(1):138-139.
[22]吕娜娜,谢剑,杨建江.大型LNG低温储罐建造技术综述[J].特种结构,2010(2),27(1):105-108.
[23]张国中、杨炳发、王东锋、高指林、刘家员.大型LNG储罐罐顶预制及顶升工艺[J].中国造船,2010(12),51(2):418–421.
[24]GB 50010-2002,混凝土结构设计规范[S].
[25]EN 14620-5. Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 5:Testing, drying, purging and cool-down[S]. 2006.
[26]EN 14620-1.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 1: General[S]. 2006.
[27]EN 14620-2.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 2: Metallic components[S]. 2006.
[28]EN 14620-3.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 3: Concrete components[S]. 2006.
[29]EN 14620-4.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 4: Insulation components[S]. 2006.
[30]Britain Standard Institute. BS 7777 Flat-bottomed, vertical, cylindrical storage tanks for low temperature service[S]. London: Britain Standard Institute, 1993.
[31]American Petroleum Institute. API 620 Design and construction of large, welded, low-pressure storage tanks[S].Washington: API Publishing Services, 2008.
[32]BS EN 1990:2002. Eurocode-Basis of structural design[S].
[33]GB 50009-2001,建筑结构荷载规范[S].
[34]Greiner R , Derler P. Effect of imperfections on wind-loaded cylindrical shell[J].Thin-Walled Structure,1995(23):271-281.
[35]Colin H,Hansen,Anthony C,Zander. Investigation of passive control devices for potential to a launch vehicle structure to reduce the interiomoise levels during launch[R]. Passive Control Device,2001.
[36]Pricher M. Medium-length thin-walled cylinder under wind loading-case study[J]. Journal of Structure Engineering,2004(130):2062-2069.
[37]Byun C,Kapania R K. Nonlinear transient response of imperfect hyperbolic shells using a reduced method[J]. Computer&Structure,1992,44:255-262.
[38]马涛,计静.大型LNG储罐静力风致屈曲仿真[J].低温建筑技术,2011,6:82-84.
[39]吕西林,蒋欢军.结构地震作用和抗震概念设计[M].武汉:武汉理工大学出版社,2004(10).
[40]孙建刚.大型立式储罐隔震—理论、方法及实验[M].北京:科学出版社,2009(12).
[41]杨正军.混凝土受弯构件斜截面破坏仿真模拟[D].南京:南京林业大学,2007(6).
[42]凌广,吴同乐.钢筋混凝土有限元分析[J].四川建筑,2003(10),23(5):51-53.
[43]吕西林,金国芳,吴晓涵.钢筋混凝土结构非线性有限元理论与应用[M].上海:同济大学出版社,1997.
[44]周波,杨建江,王锐.大型LNG储罐风荷载作用下有限元分析[J].低温建筑技术,2011(12),12.
[45]姜忻良,高海,袁蕾.桩土与结构相互作用效应的卵形消化池三维有限元静动力分析[J].天津大学学报,2009(4),42(4):345-352.
[46]杨建江、周波、王锐.LNG储罐有限元静动力分析方法探讨[J].特种结构,2011(12),28(6).
[47]沈利英,沈士明.有限元软件在大型储罐地震动力响应中的应用[J].油气田地面工程,2009(7),28(1):47-49.
[48]江见鲸,陆新征,叶列平.混凝土结构有限元分析[M].北京:清华大学出版社,2006.
[49]谢剑,赵彤.Excel在建筑工程中的应用[M].天津:天津大学出版社,2008.
[2]黄群,夏芳.LNG储罐国产化的可行性[J].天然气工业,2010(7):80-82.王振良,李臻.
[3]国内外大型液化天然气储罐发展状况[J].河南化工,2010,27(5):2-3.
[4]马德萍.隔震LNG储罐的地震反应分析[D].哈尔滨市:哈尔滨工业大学,2007(7).
[5]张云峰,张彬,岳文彤.内罐泄漏条件下LNG混凝土储罐预应力外墙模态分析[J].大庆石油学院学报,2008(12),32(6):86-89.
[6]王伟玲.大型LNG预应力储罐静力荷载下受力性能研究[D].大庆市:大庆石油学院,2009(3).
[7]杨涛.LNG储罐壳体抗风与抗震力学性能研究[D].大庆市:大庆石油学院,2010(3).
[8]柳山.液化天然气(LNG)全容储罐结构和性能研究[D].广州市:华南理工大学,2009(12).
[9]王琪.大型LNG储罐在内罐泄漏及内压工况下的有限元分析[D].天津:天津大学建筑工程学院,2010(6):1-3.
[10]吕娜娜.大型LNG储罐有限元静力分析[D].天津:天津大学建筑工程学院,2010(6):1-16.
[11]杜帅.大型LNG储罐在不同预应力筋张拉阶段的有限元分析[D].天津:天津大学建筑工程学院,2010(6):1-4.
[12]李思.全容式LNG储罐的地震响应分析[D].天津:天津大学建筑工程学院,2010(5).
[13]孙建刚,崔利富,张营.全容式LNG储罐地震响应数值模拟研究[J].2010中国(北京)国际建筑科技大会论文集,2010:225-230.
[14]李文,张彬.内罐泄露条件下LNG储罐预应力混凝土外墙时程分析[J].科学技术与工程,2010(5),10(14):3349-3354.
[15]郭揆常.液化天然气(LNG)应用与安全[M].北京:中国石化出版社,2008.
[16]张抗.世界液化天然气发展状况与展望[J].当代石油石化,2006,14(4):31-34.
[17]杨永谦,肖金生.实用有限元分析技术—ANSYS专题与技巧[M].北京:机械工业出版社,2010(10) .
[18]王新敏.ANSYS工程结构数值分析[M].北京:人民交通出版社,2007(10).
[19]龚曙光,谢桂兰.ANSYS操作命令与参数化编程[M].北京:机械工业出版社,2004(4).
[20]尚晓江,邱峰,赵海峰,李文颖.ANSYS结构有限元高级分析方法与范例应用[M].北京:中国水利水电出版社,2006.
[21]吴浩,卢云祥.上海LNG储罐外罐建造方案研究[J].2008,8(1):138-139.
[22]吕娜娜,谢剑,杨建江.大型LNG低温储罐建造技术综述[J].特种结构,2010(2),27(1):105-108.
[23]张国中、杨炳发、王东锋、高指林、刘家员.大型LNG储罐罐顶预制及顶升工艺[J].中国造船,2010(12),51(2):418–421.
[24]GB 50010-2002,混凝土结构设计规范[S].
[25]EN 14620-5. Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 5:Testing, drying, purging and cool-down[S]. 2006.
[26]EN 14620-1.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 1: General[S]. 2006.
[27]EN 14620-2.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 2: Metallic components[S]. 2006.
[28]EN 14620-3.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 3: Concrete components[S]. 2006.
[29]EN 14620-4.Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0℃and 165℃—Part 4: Insulation components[S]. 2006.
[30]Britain Standard Institute. BS 7777 Flat-bottomed, vertical, cylindrical storage tanks for low temperature service[S]. London: Britain Standard Institute, 1993.
[31]American Petroleum Institute. API 620 Design and construction of large, welded, low-pressure storage tanks[S].Washington: API Publishing Services, 2008.
[32]BS EN 1990:2002. Eurocode-Basis of structural design[S].
[33]GB 50009-2001,建筑结构荷载规范[S].
[34]Greiner R , Derler P. Effect of imperfections on wind-loaded cylindrical shell[J].Thin-Walled Structure,1995(23):271-281.
[35]Colin H,Hansen,Anthony C,Zander. Investigation of passive control devices for potential to a launch vehicle structure to reduce the interiomoise levels during launch[R]. Passive Control Device,2001.
[36]Pricher M. Medium-length thin-walled cylinder under wind loading-case study[J]. Journal of Structure Engineering,2004(130):2062-2069.
[37]Byun C,Kapania R K. Nonlinear transient response of imperfect hyperbolic shells using a reduced method[J]. Computer&Structure,1992,44:255-262.
[38]马涛,计静.大型LNG储罐静力风致屈曲仿真[J].低温建筑技术,2011,6:82-84.
[39]吕西林,蒋欢军.结构地震作用和抗震概念设计[M].武汉:武汉理工大学出版社,2004(10).
[40]孙建刚.大型立式储罐隔震—理论、方法及实验[M].北京:科学出版社,2009(12).
[41]杨正军.混凝土受弯构件斜截面破坏仿真模拟[D].南京:南京林业大学,2007(6).
[42]凌广,吴同乐.钢筋混凝土有限元分析[J].四川建筑,2003(10),23(5):51-53.
[43]吕西林,金国芳,吴晓涵.钢筋混凝土结构非线性有限元理论与应用[M].上海:同济大学出版社,1997.
[44]周波,杨建江,王锐.大型LNG储罐风荷载作用下有限元分析[J].低温建筑技术,2011(12),12.
[45]姜忻良,高海,袁蕾.桩土与结构相互作用效应的卵形消化池三维有限元静动力分析[J].天津大学学报,2009(4),42(4):345-352.
[46]杨建江、周波、王锐.LNG储罐有限元静动力分析方法探讨[J].特种结构,2011(12),28(6).
[47]沈利英,沈士明.有限元软件在大型储罐地震动力响应中的应用[J].油气田地面工程,2009(7),28(1):47-49.
[48]江见鲸,陆新征,叶列平.混凝土结构有限元分析[M].北京:清华大学出版社,2006.
[49]谢剑,赵彤.Excel在建筑工程中的应用[M].天津:天津大学出版社,2008.