反动式汽轮机转子热应力分析及寿命管理软件的设计

发布时间：2018-02-27 18:27

本文关键词： 汽轮机转子温度场应力场 ANSYS 寿命损耗 PI接口　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国经济的高速发展,电力的生产和消费在国民经济中起着越来越大的作用,电网的峰谷差值日益突出,原来带额定负荷运行的大中容量机组将不能经常满负荷运行,而是参与调峰,调峰时启动停机和负荷变化非常频繁,导致汽轮机转子内部产生较大的温度梯度,会产生很大的热变形和热应力,并且部件内部也会有低周率的热交变应力,在高温条件下会引起材料的塑性变形,在转子表面产生裂纹,使得机组的寿命损耗与带基本负荷时相比大大增加,而汽轮机转子作为电力生产中的一个重要部件,其寿命的长短直接影响到整个生产链的运营状况,并且随着越来越多的大容量、高参数机组的投入运行,反动式汽轮机所占比重也变得越来越大,因此深入研究反动式机组转子的寿命损耗具有很重要的实际意义。运用ANSYS有限元分析软件,对某汽轮机制造厂商150MW反动转鼓式汽轮机组转子在启动过程中的温度场和应力场进行了计算分析,建立转子二维有限元模型,设置材料热属性和单元属性,首先加载换热系数和初始条件,计算出转子的温度场,随后转变单元属性,加载材料的结构属性和温度场计算结果,进行转子应力场的计算。通过转变叶片的材料为正交材料,消除离心力对热应力的抵消作用,计算结果中在调节级左右两侧拐角处的应力值与各向同性材料计算时相比大了约20MPa左右。其他表面的应力变化会根据转子叶片产生离心应力大小变化而变化,在高压缸第一级和中压缸第一级附近,其差值约为40-50MPa。此次启动用时300min,启动过程中的最大应力值出现在刚开始启动时,大小约为160MPa,远远低于转子材料的屈服极限504MPa。随后在原有寿命损耗检测软件的基础上,通过PI接口的设计,改变原计算软件的计算流程,消除PI数据库的安全隐患,实现某电厂汽轮机组在线运行情况的实时监测。
[Abstract]:With the rapid development of our economy , the production and consumption of electric power plays a more and more important role in the national economy , the peak - valley difference of the power grid is increasingly prominent , the large medium - capacity unit with rated load operation will not be always full - load operation , but the large medium - capacity unit with rated load will not always carry out full - load operation , but also has high thermal deformation and thermal stress , and the turbine rotor is used as an important part in electric power production , and the service life of the turbine rotor is directly affected to the operation condition of the whole production chain . By using ANSYS finite element analysis software , the temperature field and stress field of a 150MW reverse rotating drum type steam turbine set rotor in a steam turbine manufacturer are calculated and analyzed , the two - dimensional finite element model of the rotor is established , the thermal properties and the unit properties of the rotor are set up , the temperature field of the rotor is first loaded , the temperature field of the rotor is calculated , the structure property of the loading material and the calculation result of the temperature field are calculated , and the calculation of the rotor stress field is carried out . The effect of centrifugal force on the thermal stress is eliminated by changing the material of the blade as the orthogonal material . The stress value of other surfaces is about 20 MPa as compared with the calculation of isotropic material . The stress change of other surfaces is about 40 - 50MPa in the vicinity of the first stage of the high - pressure cylinder and the first stage of the medium - pressure cylinder . At the time of start - up , the maximum stress value appears at about 160MPa , which is much lower than the yield limit of the rotor material 504MPa . then on the basis of the original life loss detection software , through the design of the PI interface , the calculation flow of the original calculation software is changed , the potential safety hazard of the PI database is eliminated , and real - time monitoring of the on - line operation of a steam turbine group of a power plant is realized .

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK263;TP311.52

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