大容量D型锅炉的振动计算研究

发布时间：2018-01-31 12:39

本文关键词： D型锅炉管束振动热力计算应力分析数值模拟卡门涡街　出处：《江苏科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着机组向大容量、高性能发展,锅炉运行过程中的振动现象越来越普遍。特别是在变负荷下运行时,锅炉特别是炉膛内部的速度、温度及压力变化会带来管束振动变得更加严重。因此,分析锅炉的对流管束振动问题变得非常有意义且有应用价值。本文以某大容量D型锅炉为研究对象,针对其对流区管束的结构静强度及卡门涡街振动问题进行了深入的研究。首先,论述了D型锅炉总体布置和结构设计上的特点,并对D型锅炉的不同负荷工况进行了热力计算。然后,对D型锅炉对流管束的简化模型进行了有限元应力分析,结果表明其结构强度能够满足锅炉受压元件的设计要求。接着,采用数值方法模拟了D型锅炉烟道内烟气流动状况,并据此完成了D型锅炉在不同工况下对流管束后卡门涡街脱落频率数值模拟计算,进而采用快速傅里叶变换得到了对流管束的升力系数和频谱特性曲线。通过对比分析得出如下两点结论:(1)卡门涡街脱落频率的数值模拟结果与传统卡门涡街理论的计算结果变化趋势相同,数值趋于相近。(2)烟气来流速度增大,卡门涡街脱落频率也略有增长,形成卡门涡街振动的部位高度略有下降。本文的研究表明,相比传统经验计算,利用数值模拟计算得到的卡门涡街脱落频率结果更能准确地判断锅炉管束区卡门涡街诱导振动的部位,对指导锅炉工程设计更有价值。
[Abstract]:With the development of large capacity and high performance, the vibration phenomenon in boiler operation is becoming more and more common, especially the speed of boiler, especially in furnace. The change of temperature and pressure will make the vibration of tube bundle more serious. Therefore, it is very meaningful and valuable to analyze the vibration of convection tube bundle of boiler. In this paper, a large capacity D type boiler is taken as the research object. The static strength of the tube bundle and the vibration of the Karman vortex street in the convection zone are studied. Firstly, the characteristics of the general layout and structure design of the D type boiler are discussed. The thermal calculation of D type boiler under different load conditions is carried out. Then, the finite element stress analysis of the simplified model of convection tube bundle of D type boiler is carried out. The results show that the structural strength can meet the design requirements of the boiler pressure element. Then, the flue gas flow in the flue of D type boiler is simulated by numerical method. According to this, the numerical simulation of Karman vortex shedding frequency after convection tube bundle of D type boiler under different working conditions has been completed. Then the lift coefficient and spectrum characteristic curve of convection tube bundle are obtained by using fast Fourier transform. The numerical simulation results of Karman vortex shedding frequency are the same as those of traditional Carmen vortex theory. The numerical value tends to be similar. 2) the velocity of flue gas flow increases, the frequency of Karman vortex shedding increases slightly, and the height of the position where the vibration of Carmen vortex decreases slightly. The research in this paper shows that compared with the traditional empirical calculation. The frequency of Karman vortex shedding obtained by numerical simulation can more accurately judge the location of vibration induced by Carmen vortex in boiler tube bundle area, which is more valuable for guiding boiler engineering design.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK227

【相似文献】