Theoretical and Numerical Analysis of the Mechanical Erosion in Steam Turbine Blades. Part I

Martínez, Fernando Rueda; Velázquez, Miguel Toledo; Martínez, Aldo Antonio Rueda; Silva, F. Sánchez; Montes, Samuel Alcántara; Chávez, Ortega

doi:10.4236/epe.2011.33029

Cited by 5 publications

(2 citation statements)

References 10 publications

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“…Depending on the operating condition and the backpressure of the turbine the wetness mass fraction is found to be in the range between 3-8%. The condensed water environment consists of very small droplets in the submicron range as well as coarse droplets of up to 100 μm in diameter [30,31]. Nevertheless, the small droplets in the range of 0.1 to 1 μm contribute most to the concentration of the condensed environment.…”

Section: Sample Volumementioning

confidence: 99%

An optical backscatter probe for time resolved droplet measurements in turbomachines

Bosdas

Mansour

Kalfas

et al. 2015

Meas. Sci. Technol.

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The presence of particles in the flow path of turbomachines can result in undesirable engine operation. In order to improve the efficiency of turbomachines and guarantee their safe operation, the flow mechanisms that govern the particles’ need to be studied and associated with the main aerodynamic flow field. This paper describes a newly developed optical backscatter probe for droplet diameter and speed measurements in turbomachines. The miniature probe has a tip diameter of 5 mm and is capable of resolving droplets from 40 to 110 μm in diameter that travel up to 200 m s−1. The calibration of the novel probe is performed with a droplet generator capable of producing monodispersed water droplets. In addition, the probe is calibrated for droplet speed measurements in the same calibration facility. The paper conducts a detailed uncertainty analysis and describes the post processing code. In the final part of this paper the probe is used in an axial turbine with an installed spray generator to perform droplet measurements under two different operating conditions. Measurements have shown that the part load condition results in larger droplet diameters and higher relative droplet speeds. As a consequence higher erosion rates at the rotor leading edge suction side will occur when operating at part load condition.

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Section: Sample Volumementioning

confidence: 99%

An optical backscatter probe for time resolved droplet measurements in turbomachines

Bosdas

Mansour

Kalfas

et al. 2015

Meas. Sci. Technol.

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“…The experimental results showed that the model was accurate for predicting the erosion of catalyst. Moreover, similar studies have also focus on the important equipment components such as steam turbine nozzles [7][8][9] and rotor blades [10,11].…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of the Erosion Mechanism inside the Tube Sockets of Main Steam Thermometers in a Coal-Fired Power Plant

Lv¹,

Yang²,

Wei³

et al. 2023

Fluid Dynamics &Amp; Materials Processing

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Leakage occurring in the tube sockets of the main steam thermometers can seriously threaten the safe operation of coal-fired power plants. Here, assuming a 300 MW unit as a relevant testbed, this problem is investigated numerically through solution of the equations of fluid-dynamics in synergy with the mathematical treatment of relevant statistics. The results indicate that the steam can form a large-scale spiral flow inside the tube socket and continuously scour the inner wall. In the model with the protective casing setting angle of 60°, the average tangential fluid velocity can reach up to 4.8 m/s, which is about twice higher than that in the model with the protective casing setting angle of 0°. The wake disturbance generated by the flow around the thermo-sensitive body leads to differences in the fluid motion inside the tube sockets between the upstream and downstream thermometers. These differences are affected by the distance between the thermometers, the setting angle of protective casing, and other factors. The pressure of the main steam inside the tube socket for a R3 thermometer, located outside the curved pipeline, is about 1756 Pa higher than that of the L3 thermometer located outside the straight pipeline, indicating that the secondary flow generated in the curved pipeline is able to provide stronger energy for the large-scale spiral flow inside the tube socket. On the basis of these findings, an improvement scheme for the installation of longitudinal ribs in the tube sockets is proposed. The simulation results show that the average tangential velocity of the fluid within the near-wall area of tube sockets decreases by more than 90%, which should be enough to effectively alleviate the damage to the inner wall caused by high-pressure fluid or particles.

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Wet steam measurement techniques

Walker

Barham²,

Giddings

et al. 2018

Reviews in Chemical Engineering

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Abstract In recent years a greater need for power station efficiency has become evident; improving turbine blade efficiency is one of the methods proposed. This efficiency depends upon the wetness of the steam that comes into contact with the blades of the low-pressure turbine stage in general and all turbines in nuclear power generation. Therefore, measurement of the moisture content of the steam in real time in conjunction with an accurate measure of steam velocity can give an overall mass flow re-entering the turbine, allowing for a feedback control. The system can rely on one technique that can measure suspended droplets and wall-bound liquid film, or a combination of techniques can operate together. This work gives a comprehensive review of the different techniques used to measure the moisture content including the liquid film and moisture content and techniques that can give measurements on both simultaneously. Each technique has its strengths and weaknesses, and they were analysed to see which technique works best overall and which techniques can be used together.

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Theoretical and Numerical Analysis of the Mechanical Erosion in Steam Turbine Blades. Part I

Cited by 5 publications

References 10 publications

An optical backscatter probe for time resolved droplet measurements in turbomachines

An optical backscatter probe for time resolved droplet measurements in turbomachines

Numerical Analysis of the Erosion Mechanism inside the Tube Sockets of Main Steam Thermometers in a Coal-Fired Power Plant

Wet steam measurement techniques

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