Two-Objective Optimization of a Kaplan Turbine Draft Tube Using a Response Surface Methodology

The overall cost of a hydropower plant is mainly due to the expenses for civil works, mechanical equipment (turbine and control units) and electrical components. The goal of a new draft tube design is to obtain a geometry that reduces investment costs, especially the excavation ones, but the primary driver is to increase the overall machine efficiency allowing for reduced payback time. In the present study, an optimization study of the elbow-draft tube assembly of a Kaplan turbine was conducted. A CFD model for the complete turbine has been developed and validated; next, an optimization of the draft tube alone was performed using a Design of Experiments technique; finally, several optimum solutions for the draft tube were obtained using a Response Surface technique aiming at maximizing pressure recovery and minimizing flow losses. A selection of optimized geometries was subsequently post-checked using the validated model of the entire turbine and a detailed flow analysis on the obtained results could make it possible to provide insight into the improved designs. It was observed that efficiency could be improved by 1% (in relative terms), and the mechanical power increased by 1,8% (in relative terms) with respect to the baseline turbine.

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Two-Objective Optimization of a Kaplan Turbine Draft Tube Using a Response Surface Methodology

Energies ◽

10.3390/en13184899 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4899

Author(s):

Riccardo Orso ◽

Ernesto Benini ◽

Moreno Minozzo ◽

Riccardo Bergamin ◽

Andrea Magrini

Keyword(s):

Response Surface ◽

Draft Tube ◽

Flow Analysis ◽

Hydropower Plant ◽

Mechanical Equipment ◽

Kaplan Turbine ◽

Control Units ◽

Primary Driver ◽

Response Surface Technique ◽

Tube Assembly

The overall cost of a hydropower plant is mainly due to the expenses of civil works, mechanical equipment (turbine and control units) and electrical components. The goal of a new draft tube design is to obtain a geometry that reduces investment costs, especially the excavation ones, but the primary driver is to increase overall machine efficiency, allowing for a reduced payback time. In the present study, an optimization study of the elbow-draft tube assembly of a Kaplan turbine was conducted. First, a CFD model for the complete turbine was developed and validated. Next, an optimization of the draft tube alone was performed using a design of experiments technique. Finally, several optimum solutions for the draft tube were obtained using a response surface technique aiming at maximizing pressure recovery and minimizing flow losses. A selection of optimized geometries was subsequently post-checked using the validated model of the entire turbine, and a detailed flow analysis on the obtained results made it possible to provide insights into the improved designs. It was observed that efficiency could be improved by 1% (in relative terms), and the mechanical power increased by 1.8% (in relative terms) with respect to the baseline turbine.

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An analysis of the impact of draft tube modifications on the performance of a Kaplan turbine by means of computational fluid dynamics

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406217713520 ◽

2017 ◽

Vol 232 (11) ◽

pp. 1937-1952

Author(s):

Juergen Schiffer ◽

Helmut Benigni ◽

Helmut Jaberg

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Draft Tube ◽

Vertical Axis ◽

Hydropower Plant ◽

Construction Costs ◽

Turbine Efficiency ◽

Kaplan Turbine ◽

The Cost ◽

The Impact

Due to the low electricity prices in central Europe, cost optimisations related to all parts of a new hydropower plant have become increasingly important. In case of a run-of-river hydropower plant using a vertical axis Kaplan turbine, one of the cost drivers are the excavation works. Thus, a decisive factor for the reduction of construction costs is the minimisation of the construction depth of the elbow-type draft tube. In course of the design phase of a new hydropower plant in Austria, an analysis of the impact of draft tube modifications on the performance of the Kaplan turbine was carried out by applying computational fluid dynamics. The net head of the turbine with a diameter of D = 3.15 m accounts for Hnet = 9.00 m and the maximum discharge per unit is Qmax = 57.5 m3/s. After it was proven that there is a good agreement of the numerically calculated and experimentally measured turbine efficiency for the original turbine configuration, various draft tube designs were tested in order to find out their impact on the turbine efficiency and to analyse the sources of draft tube losses in detail. Finally, it was possible to find a new draft tube design representing a compromise of reduced construction costs and acceptable turbine efficiency.

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Modelling and optimisation by response surface technique for adsorption of carbon dioxide by aminated biosilica/alginate composite: Experiments, characterisation and regeneration studies

International Journal of Environmental & Analytical Chemistry ◽

10.1080/03067319.2021.1912337 ◽

2021 ◽

pp. 1-22

Author(s):

Hassan Rasoulzadeh ◽

Saeed Motesaddi Zarandi ◽

Mohamadreza Massoudinejad ◽

Mostafa M. Amini

Keyword(s):

Carbon Dioxide ◽

Response Surface ◽

Response Surface Technique ◽

Surface Technique

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Kinetic Modelling and Optimizing of Butyl Propionate over a Synthesied Material (Tungstan Phosphoric Acid) Heteropoly Catalyst Using Response Surface Technique

Annales de Chimie Science des Matériaux ◽

10.18280/acsm.450402 ◽

2021 ◽

Vol 45 (4) ◽

pp. 273-280

Author(s):

Raju Kalakuntala ◽

Srinath Surnani

Keyword(s):

Experimental Data ◽

Phosphoric Acid ◽

Response Surface ◽

Kinetic Modelling ◽

Quadratic Model ◽

Molar Ratio ◽

Catalyst Loading ◽

Response Surface Technique ◽

Optimized Conditions ◽

Surface Technique

The performance of heteropoly acid i.e., Tungstan phosphoric acid for the synthesis of butyl propionate at optimized conditions. Effect on conversion and yield of propionic acids using the Response Surface Methodology (RSM) were evaluated by different process parameters including catalyst loading, alcohol/acid molar ratio. There were no external and internal mass transmission limits. A quadratic model acquired by the variance study (ANOVA) has been shown to view experimental data successfully with the regression (R2 = 0.94 and R2 = 0.942) coefficients approaching to unity. The pseudo homogeneous kinetic model (PH) validated with experimental data to determine kinetic parameters i.e., activation energy (45.97 kJ/mol) and frequent factor (91319 L/mol-min).

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Flow Measurement to a Kaplan Turbine Using a Direct Method and an Indirect One

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.823.361 ◽

2016 ◽

Vol 823 ◽

pp. 361-366

Author(s):

Ana Maria Budai ◽

Adrian Cuzmos ◽

Cristian Fanica ◽

Damaschin Pepa ◽

Cosmin Ursoniu ◽

...

Keyword(s):

Direct Measurement ◽

Flow Rate ◽

Flow Measurement ◽

Indirect Method ◽

Direct Method ◽

The Other ◽

Hydropower Plant ◽

Kaplan Turbine ◽

A Direct Method

The paper present two different methods for measuring flow in hydropower, one direct and one indirect method. The study consists in comparing the results obtained by measurements made by both methods in a Romanian hydropower plant. The indirect method used is the Winter-Kennedy method. The other method involves direct measurement of the flow rate of water using a specialized outfit in this.

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Aerodynamic Design Optimization of an Axial Flow Compressor Rotor

Volume 5: Turbo Expo 2002, Parts A and B ◽

10.1115/gt2002-30445 ◽

2002 ◽

Cited By ~ 13

Author(s):

Chan-Sol Ahn ◽

Kwang-Yong Kim

Keyword(s):

Design Optimization ◽

Response Surface ◽

Computing Time ◽

Flow Analysis ◽

Three Dimensional ◽

Axial Flow ◽

Navier Stokes ◽

Transonic Compressor ◽

Compressor Rotor ◽

Design Variables

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.

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