摘要
随着国际能源日趋紧缺,煤化工行业在国内迅速发展,含固多相流对设备及管道的磨蚀易引发恶性事故,始终困扰着企业的安全生产。由于磨蚀机理复杂、相关设备及管道的运行工况恶劣,很难准确把握具体的失效位置。工程上多采用提升材质、加厚管壁等方法来预防磨蚀穿孔,大大提高了生产成本,但效果并不明显,磨蚀失效仍未得到有效控制。
本文针对煤制油加氢反应器至高温高压分离器管道系统的典型气液固多相流磨蚀案例,研究腐蚀与磨损耦合作用机理;在此基础上,对多相流管道系统进行几何建模和流动磨损数理建模,采用湍流模型、多相流模型和离散相模型并求解多相流场,得到液相及固体颗粒在管道内的分布情况及管道壁面的相对磨损速率,并确定整个管道系统减薄泄漏的危险区域;通过对比分析不同管道结构和固体颗粒特性,探讨各因素对管道冲蚀磨损的影响规律,结果表明在其它条件不变的情况下,管道的磨损速率随着内径的增加而减小、管道的最佳曲率半径需要根据实际情况进行确定、固体颗粒越接近球形磨损越小、颗粒粒径越大磨损越大,但当粒径大到一定程度后,磨损速率随颗粒粒径的变化不明显;对原有管道系统进行了结构优化设计和计算分析,使新结构的磨损速率降低了近60%,优化效果明显。根据本文的磨蚀预测方法对现役管道系统进行检验布点,可明显减少在役检验工作量,并确保整个管道系统的安全。
本论文的创新在于:以煤制油工艺中典型气液固多相流管道系统为研究对象,从研究腐蚀与磨损耦合作用机理出发,综合考虑液相相分率和固体颗粒磨损两个因素,采用流体动力学方法来预测磨蚀失效问题;采用单条件改变法,获得了管道的流动磨损影响规律;将预测结果及磨损规律应用于管道的结构优化和在役检验布点方案,为深入研究煤液化设备及管道的安全、稳定、长周期运行奠定了良好的理论基础。在进一步深化研究的基础上,本论文的研究成果有望推广应用于以煤化工等为代表的化工企业含固多相流设备及管道系统的磨蚀失效分析、结构优化设计、局部强化处理、在役检测定位、寿命预测、风险评估等安全保障工程,经济效益和社会效益显著。
With the increasing shortage of international energy, the coal industry is developing rapidly in China. The erosion of equipment and pipe caused by multiphase flow containing solid particles has long been a security risk for enterprises. As the erosion mechanism is very complex and the operating conditions of related equipments and pipes are terrible, it is difficult to forecast the specific failure location. The regular practice in engineering is to upgrade materials and to thicken the wall to prevent erosion perforation, which increase the cost of production greatly with no obvious effect.
In this thesis, the typical gas-liquid-solid multiphase flow pipeline that connects the hydrogenation reactor and high temperature and pressure separator of coal-to-liquid is the erosion case. The interaction of corrosion and wear is analyzed firstly. Then, the geometric and mathematical simulation model of the multiphase flow pipeline system is built. Turbulence model, multiphase flow model and the discrete phase model are adopted to solve the multiphase flow field. The distribution of liquid and solid particles in pipes, relative wear rate of pipe wall and the danger zone of entire pipeline system are obtained. Through comparative analysis of different pipe structures and characteristics of solid particles, the different influence factors on the pipeline wear are discussed. The results show that pipeline wear rate decreases with the increasing in diameter in the case of other conditions unchanged. The optimal pipe radius of curvature should be determined according to the actual situation. Spherical solid particles closer to the less wear, and the larger particle size the greater wear rate, until the diameter is large enough, the wear rate increases with the particle size does not change significantly. The piping system is designed and the related analysis and calculation is done. The results show that the wear rate of the new structure is sixty percent of the original. To determine the detection points of the active pipeline system with the erosion prediction method above can significantly reduce the workload of in-service inspection and to ensure the security of the entire pipeline system.
The innovation of this thesis is to take the pipeline of coal-to-liquid as a typical gas-liquid-solid multiphase flow to study the interaction of corrosion and wear, to analysis liquid phase fraction and the solid particles wear synthetically and predict erosion failures using Computational Fluid Dynamics Method. The law of the pipeline wear is obtained just changing one single condition. The predicted results and the law of wear, which is applied to the optimization of the pipeline structure and in-service inspection lay a good theoretical basis for the in-depth study of coal liquefaction equipment and pipeline security, stability and long-period operation. This study provides a set of corrosion-wear failure prediction, in-service inspection and structural optimization technology. On the basis of further research, the method is expected to be applied to the abrasion failure analysis, structural optimization, local enhanced processing, in-service detection, life-span prediction, risk assessment and other security engineering of multiphase flow equipment and piping systems in coal chemical industry. The economic and social benefits must be remarkable.
引文
[1]刘鸿亮,曹凤中.煤化工产业的发展与环境资源约束. 2008中国煤炭加工与综合利用技术、市场、产业化发展战略研讨会论文集[C]. 2008:158 ~ 161
[2]中华人民共和国国民经济和社会发展第十一个五年规划纲要
[3] Jun Li,Jianli Yang,Zhenyu Liu. Hydrogenation of heavy liquids from a direct coal liquefaction residue for improved oil yield[J]. Fuel Processing Technology. 2009,90(4):490~495
[4]柯伟.中国腐蚀调查报告[M].第1版.北京:化学工业出版社,2003:247 ~ 249
[5]我国防腐蚀工作概况[J].表面工程咨询. 2005,5 (4):3 ~ 4
[6] Fokeer S,Kingmana S,et al. Characterization of the cross sectional particle concentration distribution in horizontal dilute flow conveying a review[J]. Chemical Engineering Processing. 2004,43(4):677 ~ 691
[7]宋光雄,张晓庆,常彦衍,张峥,钟群鹏.压力设备腐蚀失效案例统计分析[J].材料工程,2004,2 :6 ~ 9
[8]董刚,张九渊.固体粒子冲蚀磨损研究进展[J].材料科学与工程学报,2003,21(2):307 ~ 312
[9]陈冠国,褚秀萍.关于冲蚀磨损问题[J].河北理工学院学报,1997,19(4):27 ~ 32
[10] Matthew T S,Stephen J H,Wang Q. A universal wear law for abrasion[J]. Wear,2007,262(7-8):883 ~ 888
[11] Finnie I. Erosion of surface by solid particles[J]. Wear,1960,3(2):87 ~ 103
[12] Tabakoff W,Korwar P,Hamed A. Erosion study of different materials effected by coal ash particles[J]. Wear,1987,52(1):161 ~ 173
[13] Mabrouk R,Chaouki J,Guy C. Wall surface effects on particle–wall friction factor in upward gas-solid flows[J]. Powder Technology,2008,186:80 ~ 88
[14] Hishide M. Local heat transfer coefficient distribution on a ribbed surface[J]. Enhanced Heat Transfer,1996,3(3):187 ~ 200
[15]吴伟.三体磨料磨损试验机设计研究[D].兰州:甘肃农业大学,2007
[16]方睿.贵阳电厂9#炉尾部烟道流场分析[D].重庆:重庆大学,2004
[17]沈天耀,林建忠.叶轮机械的气固两相流基础[M].第1版.北京:机械工业出版社,1994:91 ~ 98
[18]车得福,李会雄.多相流及其应用[M].第1版.西安:西安交通大学出版社,2007:15~17
[19] Rudinger G. Fundamentals of Gas-Particle Flow[M]. Elsevier Scientific Publishing Co,Amsterdam,1980
[20] Sinclair J L,Jackson R. Gas-particle flow in a vertical pipe with particle-particle interactions[J]. AIChE,1989,35(6):1473 ~ 1486
[21] Louge M,Mastorakos E,Jenkins J. The role of particle collisions in pneumatic transport[J]. Fluid Mech,1991,231(10):345 ~ 359
[22]谢灼利,张政.气力输送的数值模拟研究[J].北京化工大学学报,2001,28(1):22 ~26
[23] Cheng G,Wei F,et a1. Modeling the hydrodynamics of downer reactors based On kinetic theory[J]. Chem Eng Sol,1999,54(13):2019 ~ 2027
[24] Zheng Y,Wan X,Qian A,et al. Numerical simulation of the gas-particle turbulent flow in riser reactor based on k-ε-kp-εp two fluid model[J]. Chemical Engineering Science,2001,56(24):6813 ~ 6822
[25] Zheng Yu,WAN Xiao-tao,et al. Modeling of the gas-solid turbulent flow in a riser reactor[J]. The Chinese Journal of Process Engineering,2001,1(3):249 ~ 256
[26] WAN Xiao-tao,ZHENG Yu,et al. Numerical simulation of gas-solid turbulent flow in riser reactor—k-ε-kp-εp-θtwo phase flow model [J].J Chem Ind and Eng,2002,53(5):461~468
[27]郑雨,刘飞,魏飞.提升管内气粒流动行为的数值模拟[J].高校化学工程学报,2003,17(3):304 ~ 313
[28] Tilly G P.Erosion caused by impact of solid particles[J].Treatise On Materials Science and Technology,1979,13:287 ~ 298
[29] Kliafas Y,Holt M.LDV measurements of a turbulent air-solid two-phase flow in a 90°bend[J]. Experiments in Fluids,1987,5(2):73 ~ 85
[30]林福严,邵荷生.软磨料冲蚀磨损机理的研究[J].水利电力机械,1990,1:17 ~ 21
[31] Lee B E,Tu J Y,Fletcher C A.On numerical modeling of particle wall impaction in relation to erosion prediction:Eulerian versus Lagrangian method [J]. Wear,2002,252(3-4):179 ~ 188
[32]李志,曲敬信,赵振业,邵荷生.镍基合金涂层滑动磨损过程中磨屑的演变机理[J].润滑与密封,2003,(3):48 ~ 49,53
[33] Efird, K.D. Disturbed flow and flow accelerated corrosion in oil and gas production[J]. Proceedings: ASME Energy Resources Technology Conference. Houston,TX,1998
[34]祁世芳,王东.工业管线安全评估模式的比较与分析[J].钢结构,2002,(4):53-56
[35]陶文铨.计算传热学的近代进展[M].北京:科学出版社,2001
[36] Roache P. Computational Fluid Dynamics[M]. Hermosa,1972
[37]江亲瑜,李宝良,孙晓云.凸轮机构磨损数值仿真软件研制[J].润滑与密封,2000,(4):2~4
[38]严立,徐久军.磨损问题的仿真求解研究[J].摩擦学报,1999,19(1):50 ~ 55
[39]公铭扬,李晓刚,杜伟.流化催化剂磨损机制的研究进展[J].摩擦学学报,2007,7(1):91~96
[40]李会雄,邓晟,李良星,陈听宽,王飞.蒸汽-冷流体接触冷凝流动的数值模拟[J].工程热物理学报,2005,25(6):963 ~ 966
[41] Sussman M,Smereka P,Osher S. A Level Set Approach for Computing Solutions to Incompressible Two-Phase Flow[J]. J Computational Physics,1994,114:146 ~ 159
[42] Guegffier D,Li J. Volume of Fluid Interface Tracking with Smoothed Surface Stress Methods for 3D Flows[J]. J of Computational Physics,1999,152:423 ~ 456
[43]周力行.多相流反应流体力学[M].北京:国防工业出版社,2002
[44] Branley N,Jones W P. Large Eddy Simulation of a Turbulent Non-Premixed Flame. Combustion and Flame[J],2001,127(1-2):1914 ~ 1934
[45]林宗虎.两相流与沸腾传热[M].西安:西安交通大学出版社,2002
[46] Liang-Shih Fan,Chao Zhu. Principles of Gas-Solid Flows[M]. Cambridge University Press,1997
[47] Corwe C,Stock D,Sharma M. Particle-Source-In Cell (PSI CELL)Model for Gas-Drop Flows[C] . ASME Transactions Series I - Journal of Fluids Engineering,1977,99:325 ~ 332
[48] Crowe, C. T. The State of the Art in the Development of Numerical Models for Dispersed Two-Phase Flows[C], Proceedings of the First International Conference on Multiphase Flows,Tsukuba,1994
[49]赵玉新译. Fluent帮助中文版[M].第十九章离散相模型
[50] Herbreteau C,Bouard R. Experimental study of parameters which influence the energy minimum in horizontal gas-solid conveying [J]. Powder Technology,2000,112 (3):213 ~ 220
[51]蒲文灏,熊源泉,赵长遂等.垂直管煤粉高压密相气力输送特性的模拟研究[J].中国电机工程学报,2008,28(17):21 ~ 25
[52]张元,靳涌涛,牛海峰.磨煤机煤粉管道抗磨弯头材质研究[J].煤矿机械,2001,(2):20~23
[53]邹伟斌,陈敬明,邹捷.延长水泥细磨仓衬板使用寿命的措施及衬板材质的选取[J].新世纪水泥导报,2008,(6):39 ~ 43
[54]吴帅,王红生,杨秀秀.旋流器用渣浆泵磨损分析及减轻磨损的途径[J].选煤技术,2009,1:28 ~ 30
[55]胡金锁,郝敬敏,李治源,王莹.碳钢表面渗硼和激光热处理改性层的磨粒磨损性能和机理研究[J].摩擦学学报,2002,22(2):150 ~ 152
[56]贾富玉.循环流化床锅炉磨损及防磨方法探讨[J].泸天化科技,2006,2: 145~147,141
[57]李柏林,余先林,宋谦.水泥厂非标管道耐磨材料的选用[J].新世纪私泥导报,2007,(6):22 ~ 23
[58]姚军,章本照,樊建人.弯管减磨方法的实验研究[J].动力工程,2000,20(4):792~796
[59]姚军,陈丽华,樊建人.一种气固两相流中弯管抗磨方法的数值试验研究[J].中国电机工程学报,2002,22(5):134 ~ 138
[60]林建忠,吴法理,余钊圣.一种减轻固粒对壁面冲蚀磨损的新方法[J].摩擦学学报,2003,23(3):231 ~ 235
[61]宋国良,周俊虎,刘建忠,曹欣玉,岑可法.浓相气力输送中变径管道优化设计方法的研究[J].浙江大学学报,2005,39(11):1788 ~ 1792
[62]李燕,饶金土.循环流化床锅炉磨损机理分析与防磨措施.第一届中国循环流化床燃烧理论与技术学术会议暨全国电力行业CFB机组技术交流服务协作网第六届年会[C],2007:627-631
[63]付秀勇,胡文革.凝析气田集输管线冲刷腐蚀与防护问题[J].腐蚀与防护,2008,29(8):467 ~ 470
[64]沈新荣.抗磨肋条减少颗粒两相流对壁面磨损的机理研究[D].杭州:浙江大学,1998
[65]魏秀芝.气力输送颗粒在输送管弯头中的运动及磨损[J].黑龙江石油化工,1996,(2):36 ~39
[66]刘丽,焦舒玉.代替能源:煤炼油[J].新能源,1999,21(11) :46 ~ 49,33
[67]舒歌平.煤炭液化技术[M].北京:煤炭工业出版社,2004
[68]黄标.气力输送[M].上海:上海科学技术出版社,1982
[69]刘烈炜,胡倩,郭沨,赵新强,吴建军.硫化氢对不锈钢在酸性体系中腐蚀行为影响的研究[J].腐蚀与防护,2002,25(1):10 ~ 14
[70]化学工业部化工机械研究院主编.腐蚀与防护手册—化工生产装置的腐蚀与防护[M].北京:化学工业出版社,1991:322 ~ 380
[71]王福军.计算流体动力学分析—CFD软件原理与应用[M].第1版.北京:清华大学出版,2004:21 ~ 22
[72]曹会敏.液固循环流化床管内颗粒分布及磨损特性的研究[M].河北工业大学,2008
[73]江帆,黄鹏. Fluent高级应用与实例分析[M].北京:清华大学出版社,2008:73~ 87
[74]黄卫星,陈文梅.工程流体力学[M].第1版.北京:化学工业出版社,2001:44 ~ 65
[75]朱幼兰.初边值问题差分方法及绕流[M].第1版.北京:科学出版社,1980
[76]车得福,李会雄.多相流及其应用[M].第1版.西安:西安交通大学出版社,2007:68~74
[77]马正先.气力输送系统的弯头结构形式及合理选用[J].起重运输机械,1996,6:7 ~ 11
[78]马颖,任峻,李元东,陈体军,李炳.冲蚀磨损研究的进展[J].兰州理工大学学报,2005, 31(1):21 ~ 25
[79]里符希茨著,熊欲均,于绍和翻译.高能量头离心式鼓风机[M].北京:机械工业出版社,1982
[80]庞佑霞,陆由南,尹喜云.含沙量和沙粒粒径对QT500材料冲蚀磨损特性的影响[J].机械工程材料,2006,30(4):51 ~ 53
[81]姜胜利,郑玉贵,姚治铭. 20SiMn低合金钢在不同砂粒粒径的多相流中的损伤行为[J].金属学报,2004,40(2):163 ~ 167
[82]吴国清,方亮,邢建东,张晓峰.磨料尺寸对磨料磨损过程影响的随机模拟[J].西安交通大学学报,2001,31(5):527 ~ 531
[83]鲍崇高,潘伟,苗赫濯,齐龙浩.磨粒粒径对Si3N4结构陶瓷冲蚀磨损性能的影响[J].西安交通大学学报,2005,39(11):1219 ~ 1222,1263
[84]田立言,黄继汤,丁彤.含沙水流中闸门槽蚀损的实验研究[J].水利水电技术,1999,30(5):14 ~ 16