Performance Of Pelton Turbine Research Articles

Effect of inflow disturbances in Pelton turbine distributor lines on the water jet quality

The proper design of the manifold, distributing the flow to the individual nozzles, is crucial for the Pelton turbine performance. The generation of both energy losses and secondary flows must be reduced to a minimum to provide optimal water jet quality and, hence, efficiency. However, the inflow state due to the penstock is commonly disregarded at the design stage. By numerical flow simulation, we show how such penstock perturbations affect the water jet cross-section and axis deviation by considering different pipe bends upstream of the manifold. The two-phase flows resulting in a typical Pelton turbine manifold are predicted using the Volume-Of-Fluid (VOF) approach in conjunction with the k−ω SST turbulence closure model. Pipe bends are attached five manifold inlet diameters upstream of the manifold itself. The consequences on the secondary flows in the nozzles and the free water jet quality are reported quantitatively. The analysis shows that even small inflow perturbations into the manifold due to penstock piping significantly affect the water jet quality. A yet unreported mechanism is revealed, where the secondary flows mitigate the impact of the flow rate imbalance across the nozzle on the water jet deviation.

ANALISIS ALIRAN PADA BUCKET TURBIN PELTON 1 KW DENGAN VARIASI SPEAR NOZZLE MENGGUNAKAN METODE CFD

Pelton turbine have been used for harvesting renewable energy by extracting kineticenergy of water into mechanical energy for more than 100 years. This characteristic makes thissystem remains potential to achieve Goals #12 SDGs. During the operation, the performance ofPelton Turbine is affected by several parameters: hydraulic power, water flow rate, bucketdesign, and nozzle. Among others, nozzle design is the most challenging since this part isresponsible to drive the water direction strike the buckets, converting impulse. The performanceof existing 1 kW Pelton Turbine equipped with 15mm Spear Nozzle is believed can be improvedby varying the nozzle diameter by using low-cost CFD simulation procedure. Ansys Fluent fromAnsys Student 2021 R1 is used in this research. Represented by two-buckets facing spear nozzle,three dimensional CFD simulation is conducted. The nozzle diameter is varied to 15 mm, 14 mm,and 13 mm from two configurations. The first and second configuration is done with water flowrate 3,3 kg/s and 1,3 kg/s respectively. The results show that 15 mm nozzle diameter can producehigher power as high as 594,08 Watt with the first configuration. Even though at the secondconfiguration this 15mm nozzle diameter did not produce the highest power, other parameterssuch as splashing water and erosion effect still show that the 15mm nozzle diameter performedbetter than others. This simulation results also consistent with experimental results whichperformed by using first configuration and 15mm nozzle diameter. The results also show that thesistem performance is much higher at higher water flow rates. Therefore, the development of thesystem can be continued to by using spear nozzle with diameter higher than 15mm.

The interaction between bucket number and performance of a Pelton turbine

The Pelton turbine is a type of hydraulic turbine suitable for medium, high and ultra-high head hydropower exploitation. As energy conversion units, the Pelton turbine has numerous design parameters affecting its energy conversion efficiency. In this paper, a three-dimensional unsteady simulation was conducted to analyze the influence of bucket number on the hydraulic performance and internal flow behavior of a model Pelton turbine. Five different bucket numbers in a total runner were selected for numerical examination, including the optimal number of 21 determined by the empirical formula. As the bucket number increased with the same operating conditions, the predicted hydraulic efficiency of the Pelton turbine rose to the maximum under optimal bucket number and then decline. Compared with the optimal bucket number of 21, the hydraulic efficiency of the Pelton turbine with 15, 17 buckets decreased by 2.8 % and 1 % respectively. By analyzing the variation of torque coefficient and water sheet flow under different bucket numbers, the interacting mechanism between bucket number and performance of the Pelton turbine was discussed. Numerical result indicated that the phase difference of the single bucket torque coefficient affected by the flow pattern exerted an influence on mean of the runner torque coefficient and hydraulic efficiency. This paper provides an in-depth understanding of the bucket number to the flow mechanism in the bucket for exploring the energy conversion efficiency of the Pelton turbine.

The influence of different runner widths on the performance of micro Pelton turbine

Pelton turbine can not only utilize the high head hydraulic resources but also recover the flow kinetic energy in the pipeline. It is more and more widely used. Thus, the research on improving the efficiency and performance of Pelton turbine is important. In this paper, Boltzmann method is used to study the influence of different runner widths on the performance of a micro Pelton turbine. And two micro Pelton turbines with runner widths of 25mm and 20mm are taken as the research object. Then turbine efficiency is calculated and the internal flow characteristics of micro Pelton turbine are analyzed. The results show that the runner width has obvious influence on the efficiency. When the runner width decreases from 25mm to 20mm, the turbine efficiency decreases by 1.16%. Besides, the turbulence area in the runner decreases, and the velocity decreases. But the turbulence intensity and vorticity in the runner is enhanced, which causes more serious hydraulic loss.

Performance analysis of Pelton turbine under different operating conditions: An experimental study

In this article, an experimental work has been carried out to examine the effect of varying operating conditions on performance of Pelton turbine. The experiments have been performed for various nozzle jet diameters ( d ), volume flowrate ( Q ) and pressure head ( H ). The experimental results display that the rise in d leads to reduce the input power due to decrease in H . For a certain nozzle diameter, the results indicated that the maximum brake power increases with increasing in Q owing to increase the torque and consequently, the optimum operational condition can be achieved when using smaller d and higher Q . The best turbine performance has been found when using d = 9.5 mm and Q = 85 L/min owing to produce higher efficiency and cover large range of wheel speed. The maximum efficiency of nozzle diameters 9.5 mm, 10.5 mm, 11.5 mm and 12.5 mm have been found equal 35.5%, 33%, 29.2% and 21.6%, respectively. Hence, d has inversely effect on the turbine performance. The data clearly also indicate that d and Q have substantially influences on the power that generated by turbine. By recognizing the effects of related parameters, it is now possible to generate a higher electric power in hydroelectric power plants that operated by using Pelton turbine.

A Numerical Analysis of Fluid Flow and Torque for Hydropower Pelton Turbine Performance Using Computational Fluid Dynamics

The difficulty of delivering electrical power to rural areas motivated the researchers to explore more accessible power sources. Hydropower is considered a desirable option due to its sustainability and lower costs. Pelton turbines have been widely used in hydropower plants because of their low installation and maintenance costs. This study provides a computational fluid dynamics (CFD) model for Pelton turbine performance under various flow conditions. The model is based on the conservation of mass principle, Newton’s second law, and the first law of thermodynamics. It is used to predict the torque produced by a turbine at different rotational speeds. Previously published experimental results for the same turbine geometry and flow parameters were used to validate the model’s predictions. Validation revealed that the model can reproduce the experimental results. This provides the required robustness for its use as a tool for turbine design and modification.

Primena reverznog inženjeringa pri projektovanju radnog kola Peltonove turbine

The paper describes the innovative solution for revitalization of hydro turbines by using the techniques of reverse engineering and virtual production. The application of modern digital tools in developing, designing and producing shows substantial benefits in improving the existing hydro turbine. Model testing in these cases is not necessary to implement because as the basis is used the known geometry of existing hydro turbine runners and buckets. Digital tools allow a relatively easy way to develop new geometry, improve hydraulic performances of turbines and reach a greater level of usefulness with minimal costs. This paper aims to show optimized geometry and improvement of the Pelton turbine performance using the presented approach

Pengaruh jumlah sudu dan diameter nozel terhadap kinerja turbin pelton

Pelton turbine is one type of impulse turbine that is commonly used in hydroelectric power plants such as micro hydropower plants. The choice of the turbine is based on the high-efficiency generated by the pelton turbine. The main components of the pelton turbine are blades and nozzles. The purpose of this study was to determine the amount of blade and nozzle diameter on the performance of the pelton turbine. The research method was carried out experimentally by design and manufacture of a pelton turbine prototype. Turbines made and protected have specifications of a runner diameter of 150 mm, blade length of 31,1 mm, blade width of 14,6 mm, blade depth of 6,45 mm and number of nozzles 1 piece. From the results of the study note that the number of blades and diameter of the nozzles affect the power turbine. The highest turbine power is obtained using a number of 21 blades and 8 mm nozzle diameter of 2,15 Watts. Whereas with the number of blades 19 and 8 mm nozzle diameter, turbine power is 1,91 Watt, turbine power with 23 blades and 8 mm nozzle diameter is 1,95 Watts. Turbine power with 19 blades and 10 mm nozzle diameter is 1,4 Watts, turbine power with 21 nozzles and 10 mm nozzle diameter is 1,49 Watts and turbine power with 23 blades and 10 mm nozzle diameter is 1,41 Watts. Keywords: Number of blades, nozzle diameter, pelton turbine performance.

Numerical investigation of the jet velocity profile and its influence on the Pelton turbine performance

Numerical investigation of the unsteady flow patterns around the bucket can be helpful to improve the Pelton turbine efficiency. In fact, by studying the loss mechanisms in the flow, one can optimize the bucket design. For this purpose, an accurate investigation of the water jet is also necessary as an inlet condition for the bucket flow. The water jet ejected from the nozzle is actually non-uniform, due to the upstream turbulence and secondary flow in the distributor, bending pipes, needle and supports. This non-uniformity causes a deviation of the water jet from the ideal jet center, which is tangent to the jet circle, and it directly affects the flow patterns around the bucket. Whereas water splashing makes experimental observations very challenging, a numerical approach is effective and convenient to study the unsteady flow pattern in a Pelton turbine. In the present research, numerical analysis of the two-phase flow through the distributor, bending pipe and nozzle, has been performed. The jet velocity profile has been verified with experimental results, which are measured in the model test equipment, and good agreement is obtained for both velocity profile and jet deviation. In addition, the analysis of the bucket unsteady flow is performed using the aforementioned non-uniform jet velocity profile and the calculated flow pattern around the bucket is compared to the previous calculation using a uniform velocity profile at the inlet boundary. The difference between the two cases is discussed based on the quantitative and qualitative evaluation from the numerical analysis.

Physic of secondary flow phenomenon in distributor and bifurcation pipe of Pelton turbine

Abstract In Pelton turbine, two-phase homogeneous model is the fundamental base to investigate the flow inside the turbine. Meanwhile, flow pattern in section of the distributor and bifurcation pipe produces the secondary flow which influences the shape of the jet downstream 6 nozzles. This paper numerically investigated the dynamic process using CFX commercial code under different operating conditions. Volume of Fluid(VOF) model was used to capture the air/water interface. This work focuses on the jet bifurcation problem which can seriously influence the Pelton turbine performance and furthermore it is not yet investigated in hydraulic research. Results indicate that the shape of the distributor induces the secondary flow and Dean vortex structure which are symmetric with the central horizontal plane of the pipe and nozzles. On the other hand, this sequence of vortex develops and transits along the flow and finally affects the shape of jet. Effect of secondary flow in the distributor stretches the jet flow in vertical direction and compress it in horizontal direction. Meanwhile, bifurcating phenomenon is observed outside the nozzle which is also obtained in classical experimentations. This study reveals that the secondary flow is important to be taken into consideration to optimize the performance of Pelton turbine.

Numerical analysis of a Pelton runner water sheet flow under super-high head

The hydraulic performance of Pelton turbine is different from reaction turbines due to its unsteady flow of rotating buckets with time and space. The water sheet flow in Pelton turbine is also very complex as the jet flow is often interacted with air and itself. This paper numerically investigates the dynamic hydraulic performance of a Pelton under super-high head. Unsteady numerical simulations were performed using SST k-ω. Two-phase homogeneous model and VOF were adopted to model he free surface flow. The evolution history of water sheet flow in the buckets were presented. The distribution of pressure coefficient on the bucket surface were also analysed. The results indicate that the development of water sheet flow on the bucket surface can be divided into three stages, corresponding to the output power variation process. This calculation can be used to illustrate the hydraulic mechanism of water sheet flow evolution.

펠턴 터빈 성능에 영향을 미치는 손실계수에 관한 이론적 분석

펠턴 터빈 성능에 영향을 미치는 손실계수에 관한 이론적 분석

Performance of Pelton Turbine for Hydroelectric Generation in Varying Design Parameters

Water power is a renewable energy source which has great potential in replacing fossil energy for generating electricity. The aim of this research is to analyze the influence of vertical distance of water source (water head) and nozzle diameter on the electrical power generated by Pelton turbine. It used Pelton turbine type with 22 buckets (vanes) which employed a PMG 200 watts generator with 1 : 2 pulley transmission system. Four different values of nozzle diameter and three different values of water head were chosen as the design parameters of the turbine. The electrical power was measured in three replications for each combination of the design parameters. The research showed that water head and nozzle diameter significantly affect the power generated by the Pelton turbine. The higher the water head from the surface, the more power generated. It was found that the electric power linearly increases with the increasing of nozzle diameter. However, it reaches the peak in 9 mm nozzle diameter and is getting lower in a larger diameter. The highest electric power of 16.89 watt is observed by adjusting the water head on 4.6 m with 9 mm nozzle diameter. Those design parameters are able can produce a rotation speed at 320 rpm in the generator. By identifying the appropriate parameters, it is possible to have more power generated by the water turbine used for hydroelectric power generation plant.

Pengaruh Jarak dan Posisi Nozzle Terhadap Daya Turbin Pelton

Abstract Pelton Turbine is a turbine which use nozzle as officers the direction of a stream water in order to move around of blade turbine. The rotating of turbine blade efected by some parameters such as the distance of the nozzle, position of nozzle, diameter of nozzle, number of nozzle, and the geometry shape of the blade turbine. An experimental study to analyze the affect of distance and position nozzle to Pelton Turbine of performance. The research method used experiment parameter was position of nozzle with three variations, first position is the right side horizontal of bottom shaft turbine, second position is vertical to down direction, and third position is the left side horizontal of upper shaft turbine. The parameter of nozzle distance used five variations was 24 cm, 23 cm, 22 cm, 21 cm, dan 20 cm, which measured from the end of position nozzle to blade turbine. The result shows that the right side horizontal of bottom shaft turbine with distance of nozzle 23 cm had the maximum performance to produce a power 125 Watt with the rotation of shaft turbine 263 rpm. Abstrak Turbin Pelton adalah sebuah turbin yang menggunakan nozzle sebagai pengatur arah aliran air ke sudu turbin yang berputar. Putaran sudu turbin dipengaruhi oleh beberapa parameter antara lain jarak nozzle , posisi nozzle , diameter nozzle , jumlah nozzle , dan bentuk geometri sudu turbin. Studi eksperimen yang dilakukan pada turbin pelton dimaksudkan untuk menganalisis pengaruh posisi dan jarak nozzle terhadap pergerakkan sudu yang menentukan performa turbin pelton guna mendapatkan daya listrik yang optimum. Metode penelitian yang dilakukan menggunakan parameter pengujian yaitu posisi nozzle dengan tiga variasi yaitu pada posisi pertama adalah horizontal sebelah kanan sisi bawah poros turbin, posisi kedua adalah vertikal ke bawah, dan posisi ketiga pada horizontal sebelah kiri sisi atas poros turbin. Parameter jarak nozzle menggunakan lima variasi yaitu 24 cm, 23 cm, 22 cm, 21 cm, dan 20 cm, yang diukur dari posisi ujung nozzle terhadap sudu turbin pelton. Hasil penelitian menunjukkan bahwa posisi horizontal sebelah kanan sisi bawah dari poros turbin dengan jarak nozzle sebesar 23 cm merupakan hasil yang maksimum untuk menghasilkan putaran poros turbin sebesar 263 rpm dan mampu menghasilkan daya sebesar 125 Watt.

Effect of Flow Parameters on Pelton Turbine Performance by Using Different Nozzles

Effect of Flow Parameters on Pelton Turbine Performance by Using Different Nozzles

Performance Evaluation of Pelton Turbine: A Review

Earlier only experimental techniques were used to predict the performance of turbines. With advanced numerical techniques and increase in processing power of computers, Computational Fluid Dynamics (CFD) has emerged as an effective tool for the performance prediction of Pelton hydraulic turbine involving multi-fluid flow. Extensive work has been done for design optimization of reaction turbines using CFD. Now it is being extended for impulse turbines. The flow in reaction turbines involves only water as working medium, but in case of impulse turbines, water and air are working medium. The water jet issued from nozzle is surrounded by air and pressure around the jet and turbine is atmospheric. The performance of Pelton turbine depends upon the shape, size and quality of jet as well as shape of the buckets. In the present paper, the literature review on applications of CFD for performance prediction, design optimization of Pelton turbine have been discussed.DOI: http://dx.doi.org/10.3126/hn.v13i0.10042HYDRO NEPAL Journal of Water, Energy and EnvironmentIssue No. 13, July 2013Page: 28-35Uploaded date: 3/13/2014

Numerical analysis of the bucket surface roughness effects in Pelton turbine

The internal flow of a Pelton turbine is quite complex. It is difficult to analyse the unsteady free water sheet flow in the rotating bucket owing to the lack of a sound theory. Affected by manufacturing technique and silt abrasion during the operation, the bucket surface roughness of Pelton turbine may be too great, and thereby influence unit performance. To investigate the effect of bucket roughness on Pelton turbine performance, this paper presents the numerical simulation of the interaction between the jet and the bucket in a Pelton turbine. The unsteady three-dimensional numerical simulations were performed with CFX code by using the SST turbulence model coupling the two-phase flow volume of fluid method. Different magnitude orders of bucket surface roughness were analysed and compared. Unsteady numerical results of the free water sheet flow patterns on bucket surface, torque and unit performance for each bucket surface roughness were generated. The total pressure distribution on bucket surface is used to show the free water sheet flow pattern on bucket surface. By comparing the variation of water sheet flow patterns on bucket surface with different roughness, this paper qualitatively analyses how the bucket surface roughness magnitude influences the impeding effect on free water sheet flow. Comparison of the torque variation of different bucket surface roughness highlighted the effect of the bucket surface roughness on the Pelton turbine output capacity. To further investigate the effect of bucket surface roughness on Pelton turbine performance, the relation between the relative efficiency loss rate and bucket surface roughness magnitude is quantitatively analysed. The result can be used to predict and evaluate the Pelton turbine performance.

Numerical and experimental analysis of the hydraulic performance of a prototype Pelton turbine

Unlike the reaction turbines, the hydraulic performance of Pelton turbines varies due to the unsteady flow of the rotating buckets in time and space. This study experimentally and numerically investigates the dynamic performance of a Pelton turbine at five different operating conditions. The unsteady numerical simulations were performed with the SST turbulence model. The three-dimensional unsteady free surface sheet flow behavior in the rotating buckets was modeled by the two-phase homogeneous model. The model was used to analyze the dynamic flow patterns and the torque variations as the buckets rotated. The predicted hydraulic performance at different unit discharge rates are compared with the field test while the free surface flow patterns are compared with previous experimental and numerical results. The predicted relative efficiency agrees well with the field test results. The calculations were used to clarify the hydraulic mechanisms with unsteady free surface sheet flow in the rotating bucket.

Mathematical Model for the Effect of Blade Friction on the Performance of Pelton Turbine

Water turbines have been used in electricity generation for well over a century. Hydroelectricity now supplies 19% of world electricity. Many hydro power plants are operated with Pelton turbines, which is an impulse turbine. The main reasons for using impulse turbines are that they are very simple and relatively cheap. As the stream flow varies, water flow to the turbine can be easily controlled by changing the number of nozzles or by using adjustable nozzles. Scientific investigation and design of turbines saw rapid advancement during last century. Most of the research that had been done on turbines were focused on improving the performance with particular reference to turbine components such as shaft seals, speed increasers and bearings. There is not much information available on effects of blade friction on the performance of turbine. The main focus in this paper is to analyze the performance of Pelton turbine particularly with respect to their blade friction.

Development of Pelton turbine using numerical simulation

This paper describes recent research and development activities in the field of Pelton turbine design. Flow inside Pelton turbine is most complex due to multiphase (mixture of air and water) and free surface in nature. Numerical calculation is useful to understand flow physics as well as effect of geometry on flow. The optimized design is obtained using in-house special optimization loop. Either single phase or two phase unsteady numerical calculation could be performed. Numerical results are used to visualize the flow pattern in the water passage and to predict performance of Pelton turbine at full load as well as at part load. Model tests are conducted to determine performance of turbine and it shows good agreement with numerically predicted performance.