Torque nm against turbine rotational speedhz curve. A pelton wheel is an impulsetype water turbine invented by lester allan pelton in the 1870s. L11construction of pelton turbine mi304fluid machines. Q v t r where q is the volumetric flow rate through the turbine and v t is the tangential flow velocity. Shows students how an impulse pelton turbine works and tests its performance. The pelton wheel or pelton wheel turbine is a tangential flow impulse turbine used for high heads of water. The pelton wheel turbine is invented by lester allan pelton, an american engineer.
Water leaving those wheels typically still had high. What is the difference between a pelton wheel and the. Pelton wheel synonyms, pelton wheel pronunciation, pelton wheel translation, english dictionary definition of pelton wheel. The difference between the two is easily seen when viewing the blades from the end. Pelton wheel definition of pelton wheel by the free. This requirement for a high precision housing makes the construction of a reaction turbine impractical for this project. The function of this tank is to hydraulically isolate the turbine from deviations in the head. A turbine has speed, known as specific speed and is represented by n specific speed of a water turbine in the speed at which a geometrically similar turbine would run if producing unit power 1 kw and working under a net head of 1 m. Working and design of pelton wheel is elaborated through video animation in this lecture. The pelton wheel is a turbine to convert fluid energy to mechanical energy. Pelton wheel turbine is used in hydroelectric power plant for mechanical power generation high head applications. For the love of physics walter lewin may 16, 2011 duration. The ratio of utmost and least operating head can even be two in the case of francis turbine. The buckets are small compared to the wheel and so they have a single velocity u.
Turbine safety an important safety issue concerns the turbine. In order to understand pelton wheel you need to have knowledge about what are hydraulic turbines and also how they are classified. Turbine a machine which produce continuous power by rotation. The scroll casings are normally welded steel plate constructions. It was discovered in 188 0 by an american engineer lestera. A pelton turbine or pelton wheel is a type of hydro turbine specifically an impulse turbine used frequently in hydroelectric plants. The energy available at the turbine is only kinetic energy. Pelton turbine parts, working and design aspects the constructor. The drum has a reflector and clear cover to work with an optional tachometer to measure the speed of the turbine.
Find out why close hindi construction and working of pelton turbine engineers academy. A wheel power divided by the initial jet power, is the turbine efficiency. A small mechanical pressure gauge at the inlet of the turbine measures the inlet water pressure. In hydroelectric power plant it is used to drive the generator attached to it and the generator generates the mechanical energy of the turbine into electrical energy. Pelton wheel definition of pelton wheel by merriamwebster. Power outputw against turbine rotational speedhz curve and turbine efficiency% against turbine rotational speedhz curve 2. Dhakan, abdul basheer pombra chalil casing is an important part of vertical pelton turbine unit, which acts as a housing for runner and the support for generator. Pelton worked on a design for a water wheel that would work with the. Learn more about design, analysis, working principle and applications of pelton wheel turbine. A specific aspect of pelton turbines simulation is the fact that due to periodic change of the relative position between the waterjet and the bucket the flow is unsteady and has a free surface. The water strikes the bucket along the tangent of the runner.
Pelton turbine design of gilgel gibe ii at a runner circumferential velocity of around half the jet velocity, the maximum efficiency in the energy conversion is reached because the energy of the discharging water is at its minimum. Pelton turbine is used in the hydroelectric power plant where the water available at high head i. Different parts and their functions of pelton turbine are as follows. Pelton wheel definition is an impulse turbine or waterwheel consisting of a row of double cupshaped buckets arranged around the rim of a wheel and actuated by one or more jets of water playing into the cups at high velocity. It operates under v ery high heads upto 1800 m and requires comparatively lesser quantity of water. The fluid power is converted into kinetic energy in the nozzles. If the vane moves towards the jet, the water gains speed. Hydraulic turbines are the hydromachines to generate electricity in hydro electrical power.
Abstract sediment erosion not only reduces efficiency and life of hydropower turbines but also causes problems in operation and maintenance. Many earlier variations of impulse turbines existed, but they were less efficient than peltons design. Advanced composite pelton wheel design and study its. Design and construction of main casing for four jet vertical pelton turbine prakash k. The pelton wheel is an impulse turbine with tangential flow the water hits its wheel at a tangent. Construction and working of pelton turbine youtube. Such a turbine would be an imaginary one and is called specific turbine. At the back of the wheel is a brake drum that works with a cord and two spring balances to measure the torque in the turbine. Pelton wheel is an impulse turbine where static pressure head of water is converted into mechanical energy. As the equations indicate, when a real pelton wheel is working close to maximum efficiency, the fluid flows off the wheel with very little residual velocity. A pelton wheel is a tangential impulse turbine, and the available energy at the entrance is completely kinetic energy. The result is that an impulse turbine, specifically a pelton wheel was chosen for the turbine design.
The pelton wheel turbine is a tangential flow impulse turbine. These turbines are generally used for sites with heads greater than 300 meters. Depending on water flow and design, pelton wheels can operate with heads as. The pressure energy at the inlet and outlet of the turbine is atmospheric. The unit consists of a pelton wheel mounted in a corrosionresistant enclosure.
Here importance of bucket shape, number of buckets and bucket to jet speed ratio on performance of pelton. The dynamic characteristics of a hydro turbine power depend on set input parameter. Pelton turbine among different types of impulse turbines, pelton wheel is the only turbine beingused at present. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and. H thakkar3 1,2,3assistant professor 1,2,3department of mechanical engineering 1,2,3sankalchand patel college of engineering, visnagar, gujarat n. Children love poking sticks into things which spin around. Solution specific speed of pelton turbine is given by eq.
The pelton turbine is an impulse turbine that extracts. Kaplan turbine spiral casing runner guide vanes stay vanes draft tube cone. The water in a pelton turbine is moving quickly high velocity head, figure 2 and the turbine extracts. Hydraulic turbines are being used from very ancient times to harness the energy stored in flowing streams, rivers and lakes. Hydraulic turbine turbine is hydraulic machine which convert hydraulic energy into mechanical energy. Hydraulic turbines may be defined as prime movers that transform the. This type of turbine was created during the gold rush in 1880 by lester pelton. The flow rate and head are given h 1 m q 28,5 m3s p 288 mw 2. The design of casing requires consideration of hydraulic as well as mechanical aspects. This short animation explains how pelton wheels pelton turbines work. The energy available at the inlet of the turbine is only kinetic energy. Figure 5 and figure 6 clarify the concept of flow areas and blade symmetry.
Pelton turbine design of gilgel gibe ii uchicago geosci. Pelton wheel turbine parts and working mechanism assigned by mr. Bits of the wheel could break off and get in their eyes at high velocity. It has a large wheel or runner that has buckets turbine blades that absorb the energy in the water. Pelton wheel is designed to find out the following data. Francis turbine diagram, working, parts, advantages. Jet ratio m vs rpm when we increase the jet ratio i.
Gandhi pelton turbine the available pressure head is completely converted into kinetic energy. Pelton wheel turbine leston a pelton impulse turbine high head 4 5. Loose clothing could also be wound in by the rotating wheel causing injuries. Following are the differences between pelton wheel, francis and kaplan turbine. Apart from some energy lost to friction can be introduced by a bucket ef.
Draft tube cone runner lower cover upper cover turbine shaft spiral casing governing ring guide stay vanes vanes stay ring dajiang power plant, china power. The turbine capable of working under the high potential head of water is the pelton wheel turbine which works on the head greater than 300 m. It is a model of runner of the pelton turbine wheel. In a pelton turbine or pelton wheel water jets impact on the blades of the turbine making the wheel rotate, producing torque and power. It is good for applications with high pressure head and low flow. The pelton wheel is an important and efficient fluid power machine, used in many applications.
The runner consists of a circular disc with a suitable number of double semiellipsoidal cups known as buckets which are evenly spaced around its periphery. Hindi construction and working of pelton turbine youtube. The difference in the operating head can be extra simply controlled in francis turbine than in the pelton wheel turbine. Pelton wheel pelton turbine hydropower 3d animation youtube. The resulting jet of water is directed tangentially at buckets on the wheel producing impulsive force on them. Several factors are responsible for this erosion in hydro turbine components.
Many earlier variations of impulse turbines existed, but they were less. On the other hand francis and kaplan turbines are reacti. Looking for downloadable 3d printing models, designs, and cad files. Speed of the runner pelton wheel is usually designed with the. At each loading, note down the rotational speed rpm of the turbine using a tachometer. The pelton wheel extracts energy from the impulse of moving water, as opposed to waters dead weight like the traditional overshot water wheel. Pelton wheel turbine is the type of impulse turbine which is work under the atmospheric pressure and it work on high head which is lies in the range between 2000 meters. Pelton turbine this turbine is named after lester a.
View l11construction of pelton turbine from me 231a at iit kanpur. The real pelton runner for a real pelton runner there will always be loss we will therefore set the hydraulic efficiency to. Applying bernoulli equation to free jet shown in fig. The tangential flow velocities at inlet and outlet are. The mechanical efficiency of the pelton wheel decreases faster by wear than francis turbine.