Affiliation:
1. Alstom Power, Baden, Switzerland
Abstract
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].
Publisher
American Society of Mechanical Engineers
Cited by
8 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献