Sediment erosion in low specific speed francis turbines: A case study on effects and causes

Gautam, Saroj; Neopane, Hari Prasad; Acharya, Nirmal; Chitrakar, Sailesh; Thapa, Biraj Singh; Zhu, Baoshan

doi:10.1016/j.wear.2019.203152

Cited by 39 publications

(24 citation statements)

References 25 publications

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“…GCI value from successive mesh scheme was calculated choosing suitable variable of measurement. In current case, efficiency and erosion rate as suggested by [9] was chosen for measuring the uncertainty with different mesh scheme. The uncertainties in efficiency measurements were found to be 0.132% and 0.012% using medium grid and fine grid.…”

Section: Validation Of Numerical Model 31 Grid Convergence Studymentioning

confidence: 99%

“…Major components that are affected by sediment erosion in Francis turbines are the Guide vanes and the runner, where major energy conversion takes place. In the guide vanes, severe erosion is due to high velocity of water while flowing through it and leakage flow that travels from clearance gap [9]. In the runner, the erosion at the inlet is due to abrasion of high velocity of sediment that hits the runner blade or leakage vortices that travels from clearance gap of guide vanes [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…It was reported that clearance gap of guide vanes increased by 4.2 mm after 16500 hours of operation in a hydropower plant in Nepal [10]. In a recent study by [9] [12], power plant in India suffered severe erosion in guide vanes, runner and other component due to high sediment flow. These facts about severe erosion reported mainly in power plant of Himalayan Rivers of South Asia have been studied and several efforts have been made to minimize such effects since few decades [13].…”

Section: Introductionmentioning

confidence: 99%

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Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Lama

Gautam

Neopane

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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Sediment erosion in hydraulic turbines are severe in case of hydropower plants operating in Himalayan Rivers of Nepal. Francis turbine components are heavily eroded while hard particles as quartz flow along with water through the water conduit in power plant. In Francis turbines, the runner blades where significant portion of hydraulic energy converts in mechanical energy are heavily eroded. This is due to complexity in fluid flow while operated at different operating conditions with sediment contained water. Conventional design of Francis turbines has overlooked on the effects of sediment erosion while considering optimum efficiency at all operating conditions. This paper examines multi-objective optimization of a reference 92 kW model Francis runner for minimizing sediment erosion effects. The model turbine studied in this paper is a scale down model turbine of Jhimruk Hydropower Plant, Nepal that is severely affected by sediment erosion. It was found that sediment erosion was reduced significantly at part load, full load and best efficiency point with improvement in hydraulic performance for model turbine utilizing multi-objective optimization on runner blade design.

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Section: Validation Of Numerical Model 31 Grid Convergence Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Lama

Gautam

Neopane

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…Comparison of the calculation results with the actual wear situation allowed the factors that influence the wear of the water turbine guide vanes to be identified and an improved design method to reduce the wear was proposed. Gautam et al 4 presented a case study of an Indian power plant containing a low-specific-speed Francis turbine. Numerical analysis of the flow inside the turbine was performed to investigate the causes of the various erosion patterns that occurred in the turbine components.…”

Section: Introductionmentioning

confidence: 99%

Sediment wear of turbine guide vane before and after tungsten carbide treatment

Zhao

Peng

Yang

et al. 2022

Advances in Mechanical Engineering

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This paper describes three-dimensional unsteady simulations of sand–water flow within a turbine passage. Sand abrasion of a movable guide vane made from ZG06Cr13Ni4Mo is tested before and after tungsten carbide spray-coating. ZG06Cr13Ni4Mo forms medium- and high-strength stainless steel castings for engineering structures. Different sand particle sizes produce different wear forms on the guide vane. For 0.4-mm sediment particles, the guide vane head is more seriously worn by impact; for 0.058-mm sediment particles, the guide vane tail is more seriously worn by sediment scouring. Spray-coating the guide vane with tungsten carbide produces significant anti-sand-wear performance. Before tungsten carbide spraying, the total guide vane wear at the maximum position reached 45 μm after 90 h of testing, but after spray-coating, the guide vane wear at the maximum position was only 2.6 μm after 136 h of testing. Sand abrasion test results before and after tungsten carbide treatment are used to derive a calculation formula that provides a basis for anti-silt-abrasion hydraulic turbine design and operation. The movable guide vane’s life expectancy in a power plant was estimated. Before spraying, the guide vane had to be replaced after 22.7 months of operation at P = 11.4 MW, but it operated for 44.2 months after spray-coating.

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“…Numerous researchers have performed the studies on erosion wear of various pump materials by varying the different parameters, namely, concentration, target properties, velocity, particle size, time, etc. (Kumar et al , 2018a; Gautam et al , 2020; Singh et al , 2020).…”

Section: Introductionmentioning

confidence: 99%

Tribo-performance analysis of HVOF sprayed 86WC-10Co4Cr & Ni-Cr₂O₃ on AISI 316L steel using DOE-ANN methodology

Singh

2021

ILT

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Purpose The purpose of this paper is to carry out erosion wear investigation on high-velocity oxy-fuel (HVOF)-deposited 86WC-10Co4Cr and synergistic Ni/Chromia powder (i.e. 80Ni-20Cr2O3) on AISI 316L. Design/methodology/approach Design of experiments-artificial neural network (DOE-ANN) methodology was adopted to calculate the erosion wear. Taguchi’s orthogonal array L16 (42) was used to perform set-of-erosion experiments followed by lower-the-better rule. The artificial neural network (ANN) model is used on erosion wear data obtained from the experiments. Findings Experimental results indicate that 86WC-10Co4Cr provided better erosion wear resistance as compared to Ni/Chromia. The erosion wear of 86WC-10Co4Cr and synergistic Ni/Chromia coatings increases with an increase in time duration, solid concentration and time. The magnitude of erosion generated by ashes was comparatively lower than sand. The arithmetic mean roughness (Ra) of finished AISI 316L, 86WC-10Co4Cr and Ni/Chromia coating was found as 0.46 ± 0.13, 6.50 ± 0.16 and 7.04 ± 0.23 µm, respectively. Surface microhardness of AISI 316L, 86WC-10Co4Cr and Ni/Chromia coating was found as 197 ± 18, 1,156 ± 18 and 1,021± 21 HV, respectively. Practical implications The present results can be useful for estimation of erosion wear in slurry pumps used in mining industry for the conveying of sand and in thermal power plants for the conveying of ashes to the dyke area. Originality/value The erosion wear of HVOF-sprayed 86WC-10Co4Cr and Synergistic Ni/Chromia powders was studied experimentally as well as predicted by the ANN model, and wear mechanisms are well discussed by scanning electron micrographs.

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Sediment erosion in low specific speed francis turbines: A case study on effects and causes

Cited by 39 publications

References 25 publications

Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Sediment wear of turbine guide vane before and after tungsten carbide treatment

Tribo-performance analysis of HVOF sprayed 86WC-10Co4Cr & Ni-Cr₂O₃ on AISI 316L steel using DOE-ANN methodology

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Sediment erosion in low specific speed francis turbines: A case study on effects and causes

Cited by 39 publications

References 25 publications

Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Recent developments in the optimization of Francis turbine components for minimizing sediment erosion

Sediment wear of turbine guide vane before and after tungsten carbide treatment

Tribo-performance analysis of HVOF sprayed 86WC-10Co4Cr & Ni-Cr2O3 on AISI 316L steel using DOE-ANN methodology

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Product

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About

Tribo-performance analysis of HVOF sprayed 86WC-10Co4Cr & Ni-Cr₂O₃ on AISI 316L steel using DOE-ANN methodology