Vibration Analysis and Treatment of a Heating Steam Extraction Pipeline of A 300MW Unit

Feed-heating in steam turbines, the use of steam extracted from the turbine to heat the feed-water, is known to raise the plant efficiency and so is included in most steam turbine power plant designs. The steam is extracted through an extraction slot that runs around the casing downstream of a rotor blade row. The slot is connected to a plenum, which runs around the outside of the turbine annulus. Steam flows to the feed-heaters through a pipe connected usually to the bottom of the plenum. The steam extraction is driven by a circumferentially nonuniform pressure gradient in the plenum. This causes the mass flow rate of steam extracted to vary circumferentially, which affects the main passage flow downstream of the extraction point. The flow in the extraction plenum and the influence of the steam extraction on the mainstream aerodynamics is analyzed numerically in this paper. A complete annulus with the extraction slot and plenum together with the downstream stator and rotor blade rows is modeled in this study. The results reveal a highly nonuniform steam extraction around the annulus with the highest extraction rates from the bottom nearest the extraction pipe and the lowest at the top of the annulus. This difference in extraction rates modifies the flow angle and loss circumferential distribution downstream of the stator blade row. This study finds out that the distribution of steam extraction around the annulus and its influence on the main passage flow could be greatly improved by changing the shape and increasing the volume of the extraction slot and plenum.

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On the Question of Rational Design of the Low-Pressure Flow Channel of Turbines with Heating Steam Extraction

Proceedings of Higher Educational Institutions Маchine Building ◽

10.18698/0536-1044-2018-12-68-73 ◽

2018 ◽

Author(s):

А.А. Сидоров ◽

Keyword(s):

Rational Design ◽

Low Pressure ◽

Flow Channel ◽

Pressure Flow ◽

Steam Extraction ◽

Heating Steam

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Analysis and Troubleshooting of Steam Induced Instability for an Industrial Turbomachinery

Volume 1: 22nd Biennial Conference on Mechanical Vibration and Noise, Parts A and B ◽

10.1115/detc2009-87831 ◽

2009 ◽

Author(s):

Song-yuan Lu ◽

Zheng-feng Wu ◽

Xu Zhao

Keyword(s):

Fault Diagnosis ◽

Numerical Analysis ◽

Vibration Analysis ◽

Vibration Measurement ◽

Whole Process ◽

Fault Handling ◽

Steam Extraction

This paper presents the whole process of vibration analysis and troubleshooting of a new commissioning T6530 unit, a steam extraction and backpressure turbomachinery, which exhibited steam-excited instability during load-up. Through vibration measurement, fault diagnosis, site fault handling and stability numerical analysis of bearing and shaft train, the unit was redesigned and manufactured to resolve vibration faults finally.

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