Pelton Wheel Research Articles

Design Optimization of a Run-Of-River Small Hydropower Plant: A Case Study of Mabula Kapi Site

Prior to construction, small or large hydropower plants undergo feasibility studies, which involve technical, economic, financial, social, and environmental aspects. Technical studies, particularly, include various engineering disciplines. This study sought to conduct a component of technical feasibility studies, focused on design optimization of the turbine-plant capacity size for a run-of-river case study called Mabula Kapi, on Kaombe River, Serenje, Zambia. The study method used computational modelling, simulation, and optimization techniques, and used secondary data from previous site. A prefeasibility study conducted earlier had underestimated the turbine-plant capacity owing to underestimated discharge data, owing to lack of site gauging station. A less accurate discharge estimation method involving transposition from a gauged similar catchment had been used. A later feasibility-level site hydrological study found improved discharge data. Riding on the improved discharge data, this study found the following optimised plant design parameters based on plant design discharge of 6.20 m3/s: Installed capacity of 10.20 MW; Annual energy production of 42 GWh; Capacity factor of 47.1%; 3 x Pelton wheel of 272 rpm speed, 2.1 m diameter, 2-nozzles of diameter 0.16 m each, 21 buckets of 0.58m width each; and 3 x 4 MVA generators of 50Hz, 22-poles, and 11kV.

Investigation of flow behaviour in the nozzle of a Pelton wheel: Effects and analysis of influencing parameters

The performance of a Pelton wheel is influenced by the jet created by the nozzle. Therefore, a Computational Fluid Dynamics (CFD) simulation was proposed. In this study, the significant output parameters (outlet velocity, outlet pressure, and tangential force component) and input parameters (different pressure and spear locations) were examined. In addition, the influencing parameters and their contributing percentages to the performance of the Pelton wheel were calculated using different optimisation techniques such as Taguchi Design of Experiments (DoE), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Grey Relational Analysis (GRA) and Criteria Importance Through Intercriteria Correlation (CRITIC). The effect of input factors on the output response was examined with DoE, and the results show that the inlet pressure had the most significant impact (97.38%, 99.18%, and 97.38%, respectively, for all different spear sites with a 99% confidence level). In terms of preference values, the TOPSIS and GRA results are comparable (best ranks for simulation runs #24 and #25 and least ranks for simulations #2 and #3, respectively). The CRITIC results for the pressure parameter are in good agreement with the Taguchi ANOVA analysis. The last spear location (5 mm after the nozzle outlet), with an inlet pressure of 413685 Pa generated the best result when employing the TOPSIS and GRA techniques. The outlet pressure of the nozzle was found to have a significant impact on the flow pattern of the Pelton Wheel based on the analysis of the CRITIC, Taguchi, and CFD results.

Design and Modelling of Pelton Wheel Bucket to Improve Its Efficiency

Design and Modelling of Pelton Wheel Bucket to Improve Its Efficiency

Numerical Simulation of Different Splitter Angles of a Pelton Bucket to Increase the Power Generated by The Pelton Wheel

The efficiency of a Pelton turbine depends mostly on its geometry. A design with suitable dimensions, offers higher generation of energy. However, some of these dimensions are underappreciated because of their low influence. Therefore, this study presents through a recompilation of data, the simulation was developed in ANSYS 19®. The importance of taking in count each parameter of the geometry of a Pelton bucket, analyzing in this work the influence of the splitter angle in the force generated by a bucket. Nine geometries of a Pelton bucket are developed with splitter angles between 17 and 25°. The most suitable angle is determined, finding through the simulations that the geometry of 23° generates more force than other geometries. Simplifying the geometry and the mesh can generate faster results, however, exaggerating in the meshing process will affect the reliability of the obtained results.

Experimental Investigation on Effect of Hoop Thickness on Performance of Hooped Pelton Wheel

A recent improvement in Pelton runner design, the hooped runner, is based on a redistribution of behaviour among the buckets and hoops and which allows stresses to be minimized and efficiency is nearly equivalent to conventional Pelton Runner apart from low nozzle opening of 40% and 60%. This advanced design having a couple of superiority from the mechanical orientation as well as from the assembly point of view without any different difficulty from the hydraulic orientation that establishes the significance of this unique concept. In the present work, an actual laboratory-scale hooped Pelton runner is developed. The thickness of its hoop is varied as 2 mm, 3 mm and 4 mm and to prove the competence of this advanced design and the influence of hoop thickness on the hydraulic performance of the Pelton wheel, detailed experimental studies have been performed. From the results it has been concluded that the power output and efficiency of hooped Pelton runner are nearly the same as the conventional Pelton runner at all nozzle opening.

Modification, Simulation and Demonstration of Laboratory Scale Pelton Turbine for Waterfall Hydropower Plant

To demonstrate the concepts of using waterfall hydropower to generate energy, a Mini-Laboratory Pelton Turbine (MLPT) was designed and simulated. The principle of energy conversion from potential energy of water at high elevation to kinetic energy at lower elevation through gravity fall was used. To achieve relative continuity of supply as in waterfall, a centrifugal pump was used to deliver water into a set of three reservoirs positioned at different heights. Water from the reservoirs through pipes of different diameters was used to drive the pelton Wheel turbine. A pipe matrix that allows combination of water from two or three sources at different heights and different pipe diameters was designed to demonstrate principle of conservation of flow at a junction. In the laboratory scale design, a power of 750 W was targeted. The required flow rates from different heights of reservoirs to deliver the power were used to establish nozzle diameters, rotor size, rotational speeds and power coupling ratios. A simulation of the model was conducted with different heights, pipe diameters and flow combinations using pipe matrix, were conducted using Matlab Simulink environment. The results showed that the velocity of flow under gravity increases with height of water and the force and torque associated with the flow rate increase with flow area and height of water. The sum of flows from matrix pipes was always found to be conserved with a variance of 0.27. For water heights of 7, 9 and 11 m, the nozzle diameter was found to be 19.0, 25.4, and 38.1 mm and the corresponding jet velocities were 11.2, 12.5, and 13.8 m/s. The flow rates for the scenarios were 0.0026, 0.0046 and 0.0103 m3/s. The optimum wheel diameter was 313 mm with a power coupling of 5.6:1. Compared to other models [27, 35] from the direct use of jets from pumps, the results have similar characteristics and geometric profiles. The average velocity is lower but, flow rate is higher due to the influence of larger cross sectional area. Thus, it is possible to produce the same power output using lower pressure heads when flow rate is optimized using nozzle diameter to compensate loss in velocity. Such systems can be used to harness most of the low head waterfall in Nigeria. However, the possibility of harnessing waterfalls to generate electricity for low energy demand such as recreation centers and farm settlements is faced with problem of hard-to-reach water source due to topographic complexities.

Performance and control of a reverse osmosis unit integrated with Pelton Wheel to supply emergency electric loads under various operating conditions

Nowadays, the whole world is moving very quickly into the field of seawater desalination. This is because the world suffers from a lack of potable water. Water and energy are adjoining linked fields. The present work aims at investigating the performance of a reverse osmosis (RO) plant integrated with Pelton Wheel under various operating conditions. The main reason for using Pelton turbine instead of the pressure exchanger (PX) is the low cost of Pelton compared to that of PX. The RO system integrated with the Pelton Wheel was tested under various operating pressures of 650, 700, 750, 800, and 850 kPa. Changing the feed water pressure affects the pressure of the reject entering the Pelton wheel and this, in turn, affects the velocity of the water jet. Also, the impact of varying the feed water salinity (total dissolved solids (TDS) = 400, 500, 600, 700, and 850 ppm) and temperature (20–39 °C) on the permeate and reject of RO was tested. In addition, a theoretical modeling was built to predict the performance of the RO system. The permeate flow rate was increased by raising the RO operating pressures. The permeate flow rate was augmented from 2.5 to 4.3 L min−1 when increasing the operating pressure from 650 to 850 kPa, respectively. Therefore, the permeate flow rate is enhanced by around 72% when increasing the operating pressure by only 30%. Besides, increasing the pressure by 30% (from 650 to 860 kPa) decreased the generated power of the Pelton Wheel by approximately 72% (from 960 to 270 W, respectively). Also, increasing the feed water salinity leads to raise the salinity of RO permeate, and vice versa. The RO permeate salinity is raised from 165 to 285 ppm when increasing the operating pressure from 650 to 850 kPa, respectively. As well, the more the increase in feed water temperature, the more improve in the permeate flux and salinity. The permeate TDS was decreased from 140 ppm at feed-water temperature 20 °C to 56 ppm at feed water temperature 39 °C. In this study, the Arduino program circuit was used to supply the required emergency loads by controlling the pressure values of high-pressure pump due to easy and open code program. Finally, the theoretical modelling results are in good correspondence with the experimental results. The average deviation among the theoretical and experimental results was 3.5%.

Efficiency Assessment in a Pelton Wheel as a Function of the Bucket Exit Angle at Several Rotational Speeds

Efficiency Assessment in a Pelton Wheel as a Function of the Bucket Exit Angle at Several Rotational Speeds

A New Control Algorithm to Increase the Stability of Wind–Hydro Power Plants in Isolated Systems: El Hierro as a Case Study

The present paper proposes the implementation of a new algorithm for the control of the speed regulators of Pelton wheel turbines, used in many of the pumped hydroelectric energy storage systems that operate in isolated electrical systems with high renewable energy participation. This algorithm differs substantially from the standard developments which use PID or PI governors in that, in addition to acting on the nozzle needles and deflectors, it incorporates a new inner-loop pressure stabilization circuit to improve frequency regulation and dampen the effects of the pressure waves that are generated when regulating needle position. The proposed algorithm has been implemented in the Gorona del Viento wind–hydro power plant, an installation which supplies the primary energy needs of the island of El Hierro (Canary Islands, Spain). Although, as well as its wind and hydro generation systems, the plant also has a diesel engine based generation system, the validation of the results of the study presented here focuses on situations in which frequency control is provided exclusively by the hydroelectric plant. It is shown that implementation of the proposed algorithm, which replaces the previous control system based on a classical PI governor, is able to damp the pressure wave that originates in the long penstock of the plant in the face of variations in non-dispatchable renewable generation, a situation which occurred with a high degree of relative frequency in the case study. The damper has enabled a substantial reduction in the cumulative time and the number of times that frequency exceeded different safety margins. Damper incorporation also reduced the number of under-frequency pump unit load shedding events by 93%.

A Comprehensive Review on Investigation of Sediment Erosion of Pelton Wheel Turbine

Hydro turbines installed at different hydropower plants face the issue of sediment erosion. Sediment erosion is an ambiguous phenomenon influenced by several parameters, including silt concentration, size, jet velocity, diameter, and fluid viscosity. Silt erosion imposes severe issues for hydropower plants, like shutdown and maintenance costs. The hydro turbine efficiency decreases with the increase in sediment erosion and eventually the breakdown of turbine components. Various researchers conducted small-scale experimental bench studies and numerical simulations to analyze the influence of the above-mentioned parameters on silt erosion, but the actual flow conditions are too complex to simulate. Therefore, no such erosion model has been developed to predict exact erosive wear. This paper presents an extensive review of the literature survey on sediment erosive wear of hydro turbines, both the adopted methodology by previous studies and parameters affecting sediment erosion in Pelton turbine are summarized. Based on literature studies, various aspects of erosive wear, parameters influencing it, and its severe effects on efficiency are thoroughly discussed. Appropriate remedial measurements for erosive wear made by multiple researchers, erosion models developed so far, and their measuring accuracy and the future scope of this research study are articulated in detail.

Adaptive MOMEDA model based variational mode decomposition for Pelton wheel fault detection

A critical step in fault diagnosis is determining the frequency of faults. Variational mode decomposition (VMD) is extensively employed for this purpose since it can describe the signal in the time-frequency domain. On the other hand, the VMD frequently fails to analyse non-stationary data containing low-frequency disturbances/noises. A multipoint optimal minimal entropy deconvolution adjusted (MOMEDA) is used with VMD in this research to improve defect detection performance in the presence of low-frequency disturbances. The filter length has a strong influence on the output of MOMEDA thus choosing the right one is a critical step in recovering a periodic pulse in the event of a weak defective signal. Improved grey wolf optimization (GWO) adaptively selects the appropriate filter length using the autocorrelation energy as its fitness function. The GWO is improved by introducing a gaussian mutation strategy which maintains the proper balance between the exploration and exploitation process. The proposed method has been applied to investigate the bucket defects of the Pelton wheel. The raw vibration signal is first decomposed into a series of modes using VMD. Second, the MOMEDA model is used to purify each mode by reducing low-frequency noise interference. The modes processed by MOMEDA are reconstructed again into a pure signal. Finally, the Hilbert envelop spectrum of the pure signal is obtained to determine the fault frequency. The same is verified from the theoretical fault feature frequency of the turbine bucket. The performance of the proposed method in extracting fault frequency accurately is also compared with other two models: (a) MOMEDA model with ensemble empirical mode decomposition (EEMD) and (b) MOMEDA model with complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN). The comparison results proved the efficacy and superiority of the proposed method.

Effect of flow variation in the Pelton wheel nozzle by design modification of spear

The design of the spear plays a key role in the Pelton wheel. In general, the spear is useful for increasing the velocity outlet of the nozzle. The maximum amount of the output velocity of the nozzle is mainly controlled by the spear. In this paper, the flow analysis in the Pelton wheel nozzle has been performed by varying the surface design of the spear with different dumps in different shapes and placed at different distances and with different sizes. The simulation in the paper is performed to obtain the optimal shaper and the optimal position for the complexity of the problem. We used the Taguchi design optimization method to obtain the optimal shaper to create the nozzle's higher velocity output. The flow simulation is performed in the ANSYS fluent software and the simulation is performed in fluent with the k-ε; the flow simulation is performed in the two-dimensional analysis. Taguchi optimization is performed in the Minitab software. The most optimal condition for the spear to obtain the maximum velocity is at the following aspect the model is inside a triangle and the overall length of the bump is 1mm and the number of bumps is 4 and the distance between the bumps is 1.75 mm from each other.

Design and Development of Broach Cleaning Mechanism

Broaching is most commonly used in industries for rapid and correct profiling of metal work piece. Broaching can be used to generate any desired shape by means of tool called broach. The profile that is largely produced is keyway and Splines. The keyways and splines are required in automotive components such as gears and pulleys. The closure relates to Design and development device used for cleaning broach tool compromising of a circular brush that rotate around the broach through a compressed air (Pelton Wheel turbine Like Mechanism) designed specifically for broaching machine to remove the metal chips accommodated in-between broach tool tooth and thus improve productivity of the broaching machine. A basic overview of burr formation and removal is presented in this paper. The main advantages, disadvantages, limitations, part quality and precision of these operations are presented.

Analysis on influence of bucket angle of Pelton wheel turbine for its structural integrity using aluminium alloy (A390), austenitic stainless steel (CF20), grey cast iron (325) and martensitic stainless steel (410)

Pelton wheel turbine converts gravitational energy of elevated water into a mechanical work. During the process, the turbine buckets experience equivalent stress and total deformation that lead to material failure due to the impingement of high velocity water jet on it. Bucket angle influences the structural integrity of the turbine bucket. Hence it was intended to simulate and study the effect of bucket angle on the equivalent stress and total deformation using different materials viz. aluminium alloy (A390), austenitic stainless steel (CF20), grey cast iron (325) and martensitic stainless steel (410). In this investigation equivalent stress distribution and total deformation in the bucket have been established at various bucket angles (145°, 150°, 155°, 160° and 165°) for the selected materials. Simulation results revealed that lower values of maximum equivalent stress and total deformation occur at the bucket angle of 155°, for all the materials. And the maximum equivalent stress and total deformation induced in the bucket was inferred to be lower for martensitic stainless steel, at all bucket angles. Based on the simulation results, martensitic stainless steel is proved to be a better material for turbine bucket.

An amended grey wolf optimization with mutation strategy to diagnose bucket defects in Pelton wheel

A deep learning-based defect identification scheme for the Pelton wheel has been developed. Initially, the raw vibration signal is passed through a time-varying filter based empirical mode decomposition (TVF-EMD). Filter parameters of TVF-EMD are optimized by a newly developed optimization algorithm i.e., amended grey wolf optimization (AGWO) with Kernel estimate for mutual information (KEMI) as its fitness function. The prominent IMF obtained is used to construct scalogram and prepare dataset. The training dataset trains the convolutional neural network (CNN) model whose accuracy was evaluated by the test dataset and founds to be 100%. The proposed AGWO algorithm was evaluated on twenty-three classical benchmark functions and the Wilcoxon test. Results obtained at benchmark functions and the Wilcoxon test validate the efficiency and superiority of the proposed method as compared to other techniques. A CNN classifier is compared with other learning models which suggested that CNN outperforms all learning models.

Pelton Wheel Bucket Fault Diagnosis Using Improved Shannon Entropy and Expectation Maximization Principal Component Analysis

Pelton Wheel Bucket Fault Diagnosis Using Improved Shannon Entropy and Expectation Maximization Principal Component Analysis

An effective health indicator for the Pelton wheel using a Levy flight mutated genetic algorithm

Fluctuations in the head, discharge, and contaminants in the flow can damage parts of the Pelton wheel. An artificial intelligence technique has been investigated for the automatic detection of bucket faults in the Pelton wheel. Features sensitive to defect conditions are extracted from the raw vibration signal and its variational mode decomposition (VMD). The issue of slow convergence speed of the genetic algorithm during optimization is duly addressed by implementing a Levy flight mutated genetic algorithm (LFMGA) while finding the optimal parameters (regularization parameter and kernel function) of a support vector machine (SVM). The efficacy of the proposed LFMGA is tested against different optimization benchmark functions. The results indicate that the proposed algorithm is stable on the basis of the small standard deviation. Using optimized SVM parameters, the SVM model is trained to prepare a classification model with 10-fold cross-validation. After training, the SVM model is tested for fitness evaluation. The overall recognition rate of the SVM model for identification of defects is found to be 98.84% with training time 27.06 s per iteration. A healthy condition is also compared with splitter wear, added mass defect, and missing bucket conditions separately using the VMD–SVM model and shows a recognition rate of 99.17%, 98.33%, and 98.12%, respectively.

STRUCTURAL ANALYSIS OF PELTON BUCKET WITH AISI 1020 STEEL AND STRUCTURAL STEEL MATERIAL BY USING SOLID WORKS AND ANSYS

Pelton Turbine is the hydraulic turbine, type of impulse turbine. An Impulse turbine generally suitable for the low flow rate and high head. The discharge water from the nozzle impacts the bucket of the Pelton wheel to produce the hydropower. There are some reasons behind the failure of the Pelton bucket like as: silt erosion, cavitation, fatigue etc. The main reason behind the fatigue failure is the material property and stress concentrations. A high concentration of stresses occurs at the root of the bucket due to its cantilever structure each time a bucket experiences the impact of the water jet. In this work, there are two materials AISI 1020 Steel and Structural Steel have been considered for analyzing the Pelton bucket. For the 3D CAD model of Pelton bucket Solid works 14.0 and for simulation work ANSYS 15.0 software has been used. In simulation work analysis types were static structural. This paper focuses on von-mises stress, total deformation of von-mises strain to analyze the suitable material for the Pelton bucket. From the obtained results it has been observed that among both materials Structural Steel is suitable for bucket due to low-stress concentration, total deformation and strain.

A Study to Improve the Efficiency and Performance of a Pelton Wheel using Potential Energy at Low Heads

A Study to Improve the Efficiency and Performance of a Pelton Wheel using Potential Energy at Low Heads

Improving the mechanical efficiency of a Pelton Wheel impulse turbine at Low head during operation

Improving the mechanical efficiency of a Pelton Wheel impulse turbine at Low head during operation