Experimental Investigation Into Thermal Behavior of Steam Turbine Components: Part 2—Natural Cooling of Steam Turbines and the Impact on LCF Life
Experimental Investigation Into Thermal Behavior of Steam Turbine Components: Part 2—Natural Cooling of Steam Turbines and the Impact on LCF Life
复制标题
汽轮机部件热行为实验研究：第 2 部分 — 汽轮机自然冷却及其对 LCF 寿命的影响
DOI：
10.1115/gt2012-68759
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
A. Ehrsam
中科院分区：
文献类型：
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作者：
G. Marinescu;A. Ehrsam
汽轮机涡轮机冷却对循环疲劳寿命有重要影响。停机后较低的初始金属温度导致在下一次启动期间要克服的较高的温差。通常，较低的初始金属温度导致较高的启动应力。为了优化汽轮机的循环运行，必须充分了解自然冷却，这对转子尤其具有挑战性，本文描述了一种二维数值方法，用于评估包括转子、汽缸、阀门和主管道在内的自然冷却过程中的热状态。冷却计算的概念是，在汽封蒸汽吸入阶段，用等效的流体传导率代替蒸汽总浮力，从而对金属部件产生相同的热效应。基于测量结果计算流体等效电导率。该方法是校准与实验数据。最后，循环寿命的预测冷却演变的高度敏感的性质被证明。本文是论文[1]的补充。版权所有© 2012阿尔斯通技术有限公司。
Steam turbine cool-down has a significant impact on the cyclic fatigue life. A lower initial metal temperature after standstill results in a higher temperature difference to be overcome during the next start-up. Generally, lower initial metal temperatures result in higher start-up stress. In order to optimize steam turbines for cyclic operation, it is essential to fully understand natural cooling, which is especially challenging for rotors.A two-dimensional numerical procedure is described for the assessment of the thermal regime during natural cooling including the rotors, casings, valves and main pipes. The concept of the cooling calculation is to replace the steam gross buoyancy during the gland steam ingestion phase by an equivalent fluid conductivity, that gives the same thermal effect on the metal parts. The fluid equivalent conductivity is calculated based on measurements. The approach is calibrated with experimental data. Finally, the highly sensitive nature of the cyclic lifetime to the predicted cooling evolution is demonstrated. This paper is complementary with the paper [1].Copyright © 2012 by Alstom Technology Ltd.