大型汽輪發(fā)電機組進汽方式對軸系振動特性影響研究
發(fā)布時間:2018-01-25 06:10
本文關(guān)鍵詞: 汽輪機 進汽方式 振動 重疊度 閥序切換 出處:《東南大學(xué)》2015年碩士論文 論文類型:學(xué)位論文
【摘要】:隨著科技和工業(yè)的快速發(fā)展,大型汽輪發(fā)電機組在工業(yè)生活中扮演著舉足輕重的角色。噴嘴配汽方式以其部分負荷下調(diào)節(jié)汽門節(jié)流損失小、響應(yīng)外界負荷要求速度快和運行經(jīng)濟性好的突出優(yōu)點,成為定壓運行汽輪機的主要配汽方式。所以在試運行期結(jié)束后,為了提高機組運行的經(jīng)濟性,應(yīng)將汽輪機的控制方式從單閥運行切換至順序閥運行。然而大量工程實際表明:在單閥切換成順序閥運行后往往出現(xiàn)軸振不穩(wěn)定、瓦溫高和調(diào)門晃動等問題,有些機組甚至不能在順序閥方式下正常運行。由于部分進汽問題涉及到轉(zhuǎn)子動力學(xué)、軸承動力特性、閥門優(yōu)化設(shè)計等,所以研究此類故障的機理和解決方案不僅有必要,也很有工程實際意義。本文以某臺部分進汽下發(fā)生不穩(wěn)定振動的600MW機組為例,首先利用汽輪機原理及調(diào)節(jié)級變工況計算,建立考慮一定重疊度的調(diào)節(jié)級的剩余汽流力計算模型,計算結(jié)果顯示不同進汽方式下剩余汽流力的值相差很大。然后建立基于Reynolds方程的滑動軸承求解模型,利用有限差分法進行求解,將不同進汽方式下剩余汽流力作用到高壓轉(zhuǎn)子上后,發(fā)現(xiàn)軸承的載荷和載荷角發(fā)生改變,軸承的動力特性也隨之改變。最后通過建立汽輪機高壓轉(zhuǎn)子-軸承動力特性的有限元分析模型,分析了不同閥序?qū)S承動力特性的影響,進而對該機組閥序切換時的不穩(wěn)定振動現(xiàn)象做出合理解釋,同時也表明,綜合閥序調(diào)整和閥門優(yōu)化能夠有效解決機組在閥序切換時的問題。
[Abstract]:With the rapid development of technology and industry, large turbine-generator units play an important role in industrial life. The nozzle steam distribution mode adjusts the valve throttle loss with its partial load. In response to the outstanding advantages of high speed and good operation economy, it has become the main steam distribution mode of the constant pressure steam turbine. So after the trial operation period, in order to improve the economic operation of the unit. The control mode of steam turbine should be switched from the operation of single valve to the operation of sequential valve. However, a large number of engineering practice shows that after the operation of single valve to sequential valve, there are many problems such as instability of shaft vibration, high of watt-temperature and sloshing of adjusting door. Some units can not even operate normally in the sequential valve mode. Due to partial steam intake problems related to rotor dynamics, bearing dynamic characteristics, valve optimization and so on. Therefore, it is not only necessary to study the mechanism and solution of this kind of fault, but also of engineering practical significance. This paper takes a 600MW unit with unstable vibration under some steam inlet as an example. Firstly, by using the principle of steam turbine and the calculation of variable working condition of regulating stage, the calculation model of residual steam flow force of regulating stage considering certain overlap degree is established. The results show that there is a great difference in the residual steam flow force in different steam intake modes. Then a sliding bearing solution model based on Reynolds equation is established and solved by the finite difference method. When the residual steam flow force is applied to the high pressure rotor in different inlet modes, it is found that the load and load angle of the bearing are changed. Finally, the influence of different valve sequence on bearing dynamic characteristics is analyzed by establishing the finite element analysis model of high-pressure rotor-bearing dynamic characteristics of steam turbine. Furthermore, the unstable vibration of the unit during valve sequence switching is explained reasonably, and it is also shown that the integrated valve sequence adjustment and valve optimization can effectively solve the problem of valve sequence switching.
【學(xué)位授予單位】:東南大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2015
【分類號】:TM311
【參考文獻】
相關(guān)期刊論文 前10條
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