Erosion wear of the blades of wet-steam turbine stages: Present state of the problem and methods for solving it

Ryzhenkov, V. A.; Lebedeva, A. I.; Mednikov, A. F.

doi:10.1134/s0040601511090138

Cited by 30 publications

(11 citation statements)

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“…The increase in the blade length increases the tip speed of the blade to as high as 900 m/s. Such high speed, in the wet steam medium, causes erosion in the blade [18]. Figure 1a illustrates the sequence of the erosion process experienced in a steam turbine blade.…”

Section: Water Droplet Erosion: Background and Industrial Applicationsmentioning

confidence: 99%

Water Droplet Erosion of Wind Turbine Blades: Mechanics, Testing, Modeling and Future Perspectives

Ibrahim

Medraj

2019

Materials

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The problem of erosion due to water droplet impact has been a major concern for several industries for a very long time and it keeps reinventing itself wherever a component rotates or moves at high speed in a hydrometer environment. Recently, and as larger wind turbine blades are used, erosion of the leading edge due to rain droplets impact has become a serious issue. Leading-edge erosion causes a significant loss in aerodynamics efficiency of turbine blades leading to a considerable reduction in annual energy production. This paper reviews the topic of water droplet impact erosion as it emerges in wind turbine blades. A brief background on water droplet erosion and its industrial applications is first presented. Leading-edge erosion of wind turbine is briefly described in terms of materials involved and erosion conditions encountered in the blade. Emphases are then placed on the status quo of understanding the mechanics of water droplet erosion, experimental testing, and erosion prediction models. The main conclusions of this review are as follow. So far, experimental testing efforts have led to establishing a useful but incomplete understanding of the water droplet erosion phenomenon, the effect of different erosion parameters, and a general ranking of materials based on their ability to resist erosion. Techniques for experimentally measuring an objective erosion resistance (or erosion strength) of materials have, however, not yet been developed. In terms of modelling, speculations about the physical processes underlying water droplet erosion and consequently treating the problem from first principles have never reached a state of maturity. Efforts have, therefore, focused on formulating erosion prediction equations depending on a statistical analysis of large erosion tests data and often with a combination of presumed erosion mechanisms such as fatigue. Such prediction models have not reached the stage of generalization. Experimental testing and erosion prediction efforts need to be improved such that a coherent water droplet erosion theory can be established. The need for standardized testing and data representation practices as well as correlations between test data and real in-service erosion also remains urgent.

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Section: Water Droplet Erosion: Background and Industrial Applicationsmentioning

confidence: 99%

Water Droplet Erosion of Wind Turbine Blades: Mechanics, Testing, Modeling and Future Perspectives

Ibrahim

Medraj

2019

Materials

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“…An accurate WDE model has to account for all parameters influencing the process (i.e., impact velocity, droplets diameter, impact angle, number of impacts, hardness and roughness of the target material [10,11]). Liquid erosion is a common issue in some other applications (i.e., fogging systems and overspray in gas turbines [12,13], rain erosion in wind turbines [14], wet steam flow in steam turbines [15][16][17]). However, no models are available for the specific application in study and the ones developed for other applications are not appropriate because they neglect some aspects that become critical in this case.…”

Section: Introductionmentioning

confidence: 99%

Water washing of axial flow compressors: numerical study on the fate of injected droplets

Agati

Gruttola

Gabriele³

et al. 2020

E3S Web Conf.

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In turbomachinery applications blade fouling represents a main cause of performance degradation. Among the different techniques currently available, online water washing is one of the most effective in removing deposit from the blades. Since this kind of washing is applied when the machine is close to design conditions, injected droplets are strongly accelerated when they reach the rotor blades and the understanding of their interaction with the blades is not straightforward. Moreover, undesirable phenomena like blades erosion or liquid film formation can occur. The present study aims at assessing droplets dragging from the injection system placed at the compressor inlet till the first stage rotor blades, with a focus on droplets impact locations, on the washing process and the associated risk of erosion. 3D numerical simulations of the whole compressor geometry (up to the first rotor stage) are performed by using Ansys Fluent to account for the asymmetric distribution of the sprays around of the machine struts, IGV and rotor blades. The simulations are carried out by adopting the k-ε realizable turbulence model with standard wall functions, coupled with the discretephase model to track injected droplets motion. Droplets-wall interaction is also accounted for by adopting the Stanton-Rutland model which define a droplet impact outcome depending on the impact conditions. The induced erosion is evaluated by adopting an erosion model previously developed by some of the authors and implemented in Fluent through the use of a User Defined Function (UDF). Two sets of simulations are performed, by considering the rotor still and rotating, representative of off-line and on-line water washing conditions, respectively. In the rotating simulation, the Multiple Reference Frame Model is used. The obtained results demonstrate that the washing process differs substantially between the fixed and the rotating case. Moreover, to quantify the water washing effectiveness and the erosion risk, new indices were introduced and computed for the main components of the machine. These indices can be considered as useful prescriptions in the optimization process of water washing systems.

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“…In view of this, in recent years, quite active attempts have been made to develop and implement active and passive methods of protection against droplet erosion [5][6][7][8][9][10]. These measures should lead to an increase in the service life of such blades before the capital repair of the turbine.…”

Section: Introductionmentioning

confidence: 99%

Experimental research results of the aluminum alloy erosion wear at variable parameters of the high droplet impact

Mednikov

Tkhabisimov

Zilova

et al. 2017

J. Phys.: Conf. Ser.

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Abstract. The paper presents the results of experimental research of the aluminum alloy D16T erosion characteristics conducted with variable parameters of high-speed drop impact. Erosion tests were carried out by using the unique research installation URI "Hydroshock rig" Erosion-M" NRU "MPEI". As a result of the work, characteristic points and periods of erosion wear development of an aluminum alloy under various impact conditions were revealed.

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Erosion wear of the blades of wet-steam turbine stages: Present state of the problem and methods for solving it

Cited by 30 publications

References 0 publications

Water Droplet Erosion of Wind Turbine Blades: Mechanics, Testing, Modeling and Future Perspectives

Water Droplet Erosion of Wind Turbine Blades: Mechanics, Testing, Modeling and Future Perspectives

Water washing of axial flow compressors: numerical study on the fate of injected droplets

Experimental research results of the aluminum alloy erosion wear at variable parameters of the high droplet impact

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