Differences between francis and kaplan turbines mech4study. Francis turbine diagram, working, parts, advantages. Efficiency as a function of head and flow are summarized on a hill curve similar to the one shown above for francis turbine operating limits are imposed by cavitation limits, maximum power and pressure surges. Eroded francis turbine components of jhimruk hydropower plant of nepal is shown in figure 1, which demonstrates the severity of erosion on different. The kaplan turbine is a propellertype water turbine which has adjustable blades. His design is extremely flexible and can be tailored to different head heights and flow rates. In the reaction turbines two effects cause the energy transfer from the flow to. In low head turbines, the net head is less than 30 m. It is developed in 19 by the austrian professor viktor kaplan. Different efficiencies, pelton turbine velocity triangles, design parameters, maximum efficiency. Francis turbine is radial flow turbine but in case of modern francis turbine water enters radially and leaves the turbine axially which is called as mixed flow turbine.
The most commonly used turbine in hydroquebecs power system. Design, performance and maintenance of francis turbines. If an impulse turbine is a bit like kicking soccer balls, a reaction turbine is more like swimmingin. This paper presents some specific methods used to design the upstream parts of the turbine such as the spiral casing and the distributor in a first part, the runner and the draft tube in a second part 3. Pdf model testing of francistype hydraulic turbines. It is an inwardflow reaction turbine that combines radial and axial flow concepts.
So runner blades of mixed flow turbine can be divided into two parts, the upper part of the blades use the reaction force of water flowing through it and the lower half is in the shape of a small bucket using the impulse action of water flowing through it. It was developed in 19 by austrian professor viktor kaplan, who combined automatically adjusted propeller blades with automatically adjusted wicket gates to achieve efficiency over a wide range of flow and water level the kaplan turbine was an evolution of the francis turbine. Francis turbines are almost always mounted with the shaft vertical, and they extract energy from the flow as moves through the turbine changing from. Chaplin encyclopedia of life support systems eolss both of these have double casings with the exhaust steam circulating in the annular space between the casings as in the case of the high pressure turbine.
The fluid enters from the penstock to a spiral casing which completely surrounds the runner. The computational model consists of spiral casing, 18 numbers of stay vanes and guide vanes, runner having numbers of blades and a draft tube. Jun 07, 2018 francis turbine can be operated for different head this is the main advantage of this turbine and due to this francis turbine has various applications. A francis turbine consists of the 5 main parts those are. The head ranges from 1070 metres and the output ranges from 5 to 200 mw. Difference between kaplan and francis turbine compare.
When analysing the performance of axial turbines, we assumed, by way of a simplification, a given stator outlet angle. Design of turbine parts in gas turbines follows the same principles. Francis turbine consists mainly of the following parts a spiral or scroll casing it is a closed passage whose crosssectional area gradually decreases along the flow direction. Such types of hydraulic turbines are called as mixed flow turbines. The approximate ranges of head, flow and power applicable to the different turbine types are summarised in the chart of figure 1 up to 500kw power. The rated head and discharge for the turbine were 48 m and 7. Pdf design analysis of parts of francis turbine researchgate. Eroded francis turbine components of jhimruk hydropower plant of nepal is shown in figure 1, which demonstrates the severity of erosion on different components, especially guide vanes and runner. They combine radial and axial concepts in an inwardflow reaction turbine.
In francis turbine water flow is radial into the turbine and exits the turbine axially. The main reason of higher efficiency of francis turbine lies in the design of blades, these blades rotate using both reaction and. There are several different types of reaction turbine. The working principle, main components and its application is discussed in this article. It escapes through the draft tube located under the turbine. Besides the runner, the other major components are the scroll case, wicket gates, and draft tube. Water is introduced just above the runner and all around it and then falls through, causing it to spin. The water flowing from the reservoir or dam is made to pass through this pipe with high pressure. Its invention allowed efficient power production in low head applications that were not possible with francis turbine.
Francis turbine is enclosed in a casing, and the blades have special curved features designed to gain optimal performance from the turbine. The runner is encircled by a ring of stationary channels called as guide vanes. The upper part of the blades use the reaction force of water flowing through it. Introduction hydropower represents an almost ideal energy. Jan 23, 2018 francis turbine is the most widely used turbine in hydropower plants to generate electricity. The francis turbine is a type of water turbine that was developed by james b.
What is the difference between a pelton wheel and the francis. Simulating fluid flow through different turbine components separately is today standard proce dure. Pelton turbine or wheel is an impulsive turbine used mainly for high head hydroelectric schemes. Guide on how to develop a small hydropower plant esha 2004 6 electromechanical equipment1 this chapter gives the main description of the electromechanical equipment, some preliminary design rules and some selection criterion. Francis turbinevelocity triangles, design parameters, runner shapes for different blade speeds. Proto type tests or model tests to determine turbine performance characteristics are discussed with special. Difference between kaplan and francis turbine compare the. Francis turbines operate under a water head of 10650 meters and the generator driven by the turbine can give a power output up to 750 mw. Validation of francis water turbine cfd simulations.
Francis turbine had some limitations which were overcome by kaplan turbine. Complete francis turbine flow simulation for the whole range of discharges z. They operate in a water head from 40 to 600 m to 2,000 ft and are used. It is most efficient hydro turbine we have till date. You have clicked a page that seems to be very popular. The most popular, accounting for 80% of all hydraulic turbines in operation, is the francis turbine see figure 8. Components of francis turbine the main parts of francis turbine are. Pelton wheel is an impulse turbine where static pressure head of water is converted into mechanical energy. The cfd approach for prediction of efficiency of a 3 mw capacity horizontal axis francis turbine is presented. Geometrical description of a francis turbine parts. Francis turbine has a circular plate fixed to the rotating shaft perpendicular to its surface and passing through its center. Increase area of water exit, increase whirling action, suit for. A reaction turbine doesnt change the direction of the fluid flow as drastically as an impulse. What is the difference between a pelton wheel and the.
Francis turbine is an example of mixed flow type, in francis turbine water enters in radial direction and exits in axial direction. In the opencircuit mode figure 3a, performance tests of the model turbines figure 1. Complete francis turbine flow simulation for the whole range of. Apr 04, 2017 components of francis turbine the main parts of francis turbine are. Design of large francis turbine using optimal methods. It provides an encased water path to contain the water pressure. General arrangements for pelton, francis, kaplan and kaplan bulb turbine power plants. The invention of kaplan turbine is evolution in the field of hydraulic turbines or we can say that it is the upgrade version of francis turbine.
Pumps, turbines, and pipe networks, part 2 ch 11 young. They operate in a water head from 40 to 600 m and are used primarily for electrical power production. The hydraulic turbines can be classified based on type of energy at the inlet, direction of flow through the vanes, head available at the. Overview of a typical powerhouse the powerhouse can also be at the base of an existing dam, where the water arrives via an existing.
The kaplan turbine was an evolution of the francis turbine. Francis turbine can be operated for different head this is the main advantage of this turbine and due to this francis turbine has various applications. It was named after james bicheno francis 18151892, the american engineer who invented the apparatus in 1849. Francis turbines are the most common water turbine in use today. The turbines are of basically four types and these are water turbine, steam turbine, gas turbine and wind turbine. Turbo machines vtu notes pdf tm pdf vtu smart world. This video explains the technical points of francis turbines in plain english. It is efficient over a wide range of water head and flow rate.
The main idea is to assume steady state uniform conditions. The stationary guide vanes are fixed on the guide wheel. Francis turbine is the most common type of turbine in practice, which presents a sidebyside design of generator. It is most commonly used turbine in hydro power plant for electricity generation. Here you can download the turbo machines vtu notes pdf tm pdf vtu of as per vtu syllabus. Cfd, numerical simulation, francis turbine, fluent, parallel computing, linux cluster 1. Validation of francis water turbine cfd simulations 1. On the other hand francis and kaplan turbines are reacti. The major part of pressure drop occurs in the turbine itself, unlike the impulse turbine where. Water strikes the edge of the runner, pushes the blades and then flows toward the axis of the turbine.
Different pumps work best in different specific speed ranges. In a francis turbine, runner blades are divided into 2 parts. Its invention allowed efficient power production in lowhead applications which was not possible with francis turbines. We will also discuss here what is turbine, main parts of turbine and working principle of a turbine.
The reverse archimedes screw and the overshot waterwheel are both gravity turbines. This can be used in almost every situation but for very low heads, propeller turbines and kaplan turbines are frequently preferred. Francis turbine its components, working and application. When analysing the performance of axial turbines, we assumed, by way of a simplification, a. Find, read and cite all the research you need on researchgate. Optimization of turbine design was based on two different techniques coupled with the flow solver. With a neat sketch explain the parts of an impulse turbine. In this context, the hydraulic designer can make use of optimal methods to define a francis turbine that meet all the client requirements. Analyzing mathematical and software methods for selecting. The lower half is made in the shape of small bucket so that it uses the impulse action of water to rotate the turbine.
The francis turbine was developed by an american engineer james bichens francis around 1855. Comparing set of variable design and operating point with the basic francis turbine design, the performance improvement was. Description of the different types of turbines used for electricity production. For most of the hydraulic turbines used there is a significant component of both axial and radial flows. Guide on how to develop a small hydropower plant esha 2004 photo 6. The resulting jet of water is directed tangentially at buckets on the. L argesized francis turbine s are commonly used at hydraulic head range of 20700m. This can be used in almost every situation but for very low heads, propeller turbines. Francis turbine working principle, main parts, diagram and. Unesco eolss sample chapters thermal power plants steam turbine components and systems r. Water pressure decreases as it passes through the turbine imparting reaction on the turbine blades making the turbine rotate. It consists of a circular wheel all round the runner of the turbine. Francis turbine hydraulic characteristics hydraulic turbomachine kljucne rijeci cfd fluent francisova turbina hidraulicki turbostrojevi energetske znacajke received primljeno.
Water particle water from spiral casing r a d i a l r a d a l runner guide ivanes runner guide vanes v i e w v e w andi stay vanes and stay vanes 16. Abstract the aim for turbine design is to increase the efficiency and avoid cavitation and fractures during operation. The main components of a hydroelectric system may be classified into two groups. A brief discussion on a the design philosophy during the last 60 years with will be presented. It was designed by american scientist james francis. A francis turbine has a runner with fixed buckets vanes, usually nine or more. Francis turbine is the first hydraulic turbine with radial inflow. Introduction cfd computational fluid dynamic is today standard procedure for simulating and analysing fluid flow through hydraulic machines.
Analyzing mathematical and software methods for selecting and. Complete francis turbine flow simulation for the whole. View francis turbine ppts online, safely and virusfree. The fluid power is converted into kinetic energy in the nozzles. Reaction turbines have some primary features which differentiate them from impulse turbines. In a reaction turbine, the blades sit in a much larger volume of fluid and turn around as the fluid flows past them. Francis turbine is one of the most widely used turbine s.
Alibaba manufacturer directory suppliers, manufacturers. Difference between francis and kaplan turbine pdf 23. The pelton wheel is among the most efficient types of water turbines. Francis turbines are the most common water turbine in use today, and operate in a wide head range of 10 to 650 meters. Different parts and their functions of pelton turbine are as follows. After only 35000 hrs of operation all runners show fatigue cracks at the trailing edges close to the hub which needed to be repaired effortful. The electric generators that most often use this type of turbine have a power output that generally ranges from just a few kilowatts up t.
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