Pelton turbine working, main parts, application with diagram. The turbine runner is usually directly coupled to the generator shaft and shall be above the downstream level. Pelton wheel is the preferred turbine for hydropower when the available water source has a relatively high hydraulic head at low flow rates. Throughout its length, it has numerous openings at regular intervals to allow the working fluid to impinge on the blades of the runner. The rotation speed rpm is higher than that of the francis turbine. Hydraulic turbines are being used from very ancient times to harness the energy stored in flowing streams, rivers and lakes. First highhead power plant in the country with 18 mw francis doublespiral turbines and twin 15 mw pelton turbines. What is reaction turbine principle, working, main components and application. Failure investigation of a pelton turbine runner request pdf. The kaplan turbine runner has 38 blades while francis turbine runner has 1525 blades in general.
G, india abstracta peltonwheel impulse turbine is a hydro. To stop the runner in a short time, a small nozzle is used which directs the jet of water on the back of buckets. A francis turbine consists of the following main parts. The efficiency of a turbine is highly influenced by its runner wheel and this work aims to study the design of a kaplan turbine runner wheel. A kaplan turbine is basically a propeller with adjustable blades inside a tube. Most efficient among other impulse turbines with efficiency about 90%. Difference between pelton, francis and kaplan turbines. Number of jets obtained by dividing the total rate of flow through the turbine by the rate of flow through single jet. Its invention allowed efficient power production in lowhead applications which was not possible with francis turbines. A pelton wheel is an impulsetype water turbine invented by lester allan pelton in the 1870s. Kaplan turbine is an axial flow reaction turbine which is suitable for low heads and hence requires a large quantity of water to develop a large amount of power. Lecture on pelton turbine indian institute of technology. Kaplan turbine and francis turbine pdfcomponents, working. Francis turbine kaplan turbine tyson turbine gorlov helical turbine.
Difference between kaplan and francis turbine compare the. It is an axialflow turbine, which means that the flow direction does not change as it crosses the rotor. It operates under v ery high heads upto 1800 m and requires comparatively lesser quantity of water. The inward flow reaction turbine having radial discharge at outlet is known as francis turbine, after the name of j. Useful turbine for hydropower if water source has relatively high hydraulic heads and low flow rates. The turbine manufacturer can only give the clearance. The wheel is immersed and operates both the water velocity kinetic energy, that a pressure difference. Classification of turbines the low head kaplan turbine at the jhang branch canal in punjab, pakistan is a micro hydro power turbine. Jan 01, 2020 francis and kaplan turbines francis turbine. Dec 17, 2019 the turbine size runner, generator and powerhouse required is large. Kaplan turbine has a higher efficiency than francis turbine. Explain the general principles of pelton wheels kaplan turbines francis turbine construct blade vector diagrams for moving vanes for a pelton wheels and a francis turbine deduce formulae for power and efficiency for turbines.
The turbine size runner, generator and powerhouse required is large. This type of turbine was created during the gold rush in 1880 by lester pelton. Francis and kaplan turbines notes for civil engineering. Abstract the aim for turbine design is to increase the efficiency and avoid cavitation and fractures during operation.
However, the exit velocity is axial in kaplan runner, while it is the radial one in all other runners. Modelling and analysis of a very low head kaplan turbine. If the flow at runner exit is without swirl then the equation reduces to. The head ranges from 1070 metres and the output ranges from 5 to 200 mw. To estimate the cost of a turbine kaplan, francis or pelton, please submit the required information. Design of the runner of a kaplan turbine for small. Water enters the turbine through spiral casing, and starts entering the runner blades, passing through stay vanes and guide vanes, as it moves along the length of casing the decreasing crosssection area of the spiral casing makes sure that the pressure energy of water would remain uniform along its length, as a portion of water is also entering the runner blades. Turbine speci c speed concepts the turbine speci c speed is a quantity derived from dimensional analysis. In kaplan and propeller shaft turbines axial flow runner is used where as in francis turbine radial flow runner in use. Water strikes the edge of the runner, pushes the blades and then flows toward the axis of the turbine.
Pelton turbine among different types of impulse turbines, pelton wheel is the only turbine beingused at present. The whole arrangement of runner and buckets, inlet and braking jets are covered by the casing. Lecture on francis turbine indian institute of technology. Casing of pelton turbine does not perform any hydraulic actions but prevents the splashing of water while working and also helps the water to discharge to the tail race. Flow analysis in a rotating blade channel of a turbine runner or a pump impeller. Hydroelectric power plant, kaplan turbine, efficiency, hydraulic machinery. Performance of gangrel hydroelectric power plant a case. May 08, 2016 a tangential flow impulse type water turbine invented by lester allan pelton. A tangential flow impulse type water turbine invented by lester allan pelton. The pelton wheel extracts energy from the impulse of moving water, as opposed to waters dead weight like the traditional overshot water wheel. Francis turbines are generally arranged so that the axis is vertical although smaller turbines can have a horizontal axis.
Layout of kaplan turbine at jhang branch canal in punjab, pakistan. Kaplan turbine is employed, where a large quantity of water is available. Learn more about design, analysis, working principle and applications of pelton wheel turbine. Kaplan turbine is a low headturbine and used for heads ofless than 80 meters. It is more compact then francis turbine which can run faster and maintains high efficiency. Design, performance and maintenance of francis turbines.
So selection of type of runners is depends only on the type of turbines. Kaplan turbine the kaplan turbine is a greatdevelopment of early 19thcentury. A brief discussion on a the design philosophy during the last 60 years with will be presented. Nov 05, 2010 kaplan turbine propeller turbine kaplan turbine is a type of propeller turbine which was developed during 1900s by the austrian engineer victor kaplan 1876 1934 kaplan turbine is a low head turbine and used for heads of less than 80 metres. It escapes through the draft tube located under the turbine. A pelton turbine or pelton wheel is a type of hydro turbine specifically an impulse turbine used frequently in hydroelectric plants. General arrangements for pelton, francis, kaplan and kaplan bulb turbine. The kaplan turbine was an evolution of the francis turbine. The kaplan turbine is an axial flow reaction turbine, which means that the working fluid changes pressure as it moves through the turbine and gives up its energy. The savonius wind turbine is an aerodynamically drag based, selfstarting turbine with low cut in speed but their inefficiency curtails them to fewer applications, whereas, darrieus wind turbines. Efficiency of kaplan turbine is higher than francis turbine. What is the difference between a pelton wheel and the francis. The admission of a francis turbine is radial and the outlet is axial. General differences between francis and kaplan turbines.
Hence, these are the parameter changes that has to be incorporated in converting a francis turbine to kaplan turbine. This type of turbine is located in the old lowhead installations less than10 m where they are generally in water chamber, ie without scrollcase. Download kaplan turbine and francis turbine pdf at the end of the article. It has fixed runner blades and adjustable guide vanes. Explain the significance of specific speed to turbine selection. The runner of a kaplan turbine resembles with propeller of a ship. The variation in the operating head is difficult to control because of high heads. This operates in an entirely closed conduit to tailrace. The runaway speed is dependent of the cavitation as shown in the figure. The pelton, francis and kaplan turbines are water turbines that are rotary machines which convert kinetic energy and the. It was discovered in 188 0 by an american engineer lestera. Reaction turbine francis, kaplan and propeller turbine. Engineer, viktor kaplan and is therefore named after him as kaplan turbine.
Kaplan turbine it is an axial flow reaction turbine. The blade angle at the entrance is o 90 and the guide vane angle is o 15. Design and analysis of a kaplan turbine runner wheel. Nevertheless, compared to other types of units, such as kaplan or pelton, francis units working under offdesign conditions suffer from many types of problems and damages. It consists of spiral casing, guide mechanism and draft tube of kaplan turbine runner are similar to those of francis turbine. Like kaplan turbine, the francis is a reaction machine. However, the runner due to inertia goes on revolving for a long time.
Following are the differences between pelton wheel, francis and kaplan turbine. The kaplan is of the propellertype, similar to an airplanepropeller. What is the differences between pelton turbine and kaplan. The water at the exit leaves the blades without any tangential velocity. It was named after james bicheno francis 18151892, the american engineer who invented the apparatus in 1849. First, a theoretical design was performed for determining the main characteristics where it showed an efficiency of 94%.
The real pelton runner for a real pelton runner there will always be loss we will therefore set the hydraulic efficiency to. Pelton wheel is an impulse turbine where static pressure head of water is converted into mechanical energy. B francis an american engineer who in beginning designed inward radial flow reaction turbine. The relationship between the cost of pelton turbine c p and a flow rate q in m 3 s can be expressed by the following formula. In the propeller turbine the runner blades are fixed and nonadjustable. The speed of turbine runner is required to be maintained constant so that. Francis turbine working principle, main parts, diagram and. The runner with buckets is shown in the figure given below. Some features of the low head kaplan turbine are the following turbine runner diameter d 1. The spiral casing around the runner of the turbine is known as the volute casing or scroll case. The rotor of francis and peloton turbines has fixed blades. Many earlier variations of impulse turbines existed, but they were less efficient than peltons design. In a pelton turbine or pelton wheel water jets impact on the blades of the turbine making the wheel rotate, producing torque and power. H thakkar3 1,2,3assistant professor 1,2,3department of mechanical engineering 1,2,3sankalchand patel college of engineering, visnagar, gujarat n.
The inlet guidevanes can be opened and closed to regulate the amount of flow that can pass through the turbine. Kaplan turbine propeller turbine kaplan turbine is a type of propeller turbine which was developed during 1900s by the austrian engineer victor kaplan 1876 1934 kaplan turbine is a low head turbine and used for heads of less than 80 metres. Further a manual separated operation of each guide vane servomotor will be. Oct 24, 2016 francis turbine working principle, main parts, diagram and application. Read the lab manual and any background material needed before you come to the lab.
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