Gas turbine governing dynamics and control systems. In another situation, the mechanicalhydraulic governor on l 1500 hp turbine did not control the turbine s speed after the teeth on the pump half of a grease lubricated gear coupling, wore down the coupling between the turbine and the pump was a purchasint department special bargain. The reaction turbine is composed of moving blades nozzles alternating with fixed nozzles. Differences between francis and kaplan turbines mech4study. Reaction turbines are acted on by water, which changes pressure as it moves through the turbine and gives up its energy. Sample technical specifications of large hydraulic turbines and governing equipment for. The governing equations have been derived using the principles of conservation of mass, momentum and energy. The precise shape of water turbine blades is a function of the supply pressure of water, and the type of impeller selected. We collected most searched pages list related with governing mechanism of pelton turbine and more about it. Governing system of the turbine does the following functions. Now in reaction machines, this is done by this mechanism, i will show you.
Impulse turbines change the direction of flow of a high velocity fluid or gas jet. Keywordshydro classification, hydro turbines, turbine efficiency curve, pico hydro technology, selection charts. Penstock input pipes diameters are between 1 and 10 meters 3 and 33 feet. Experimental study of the mechanism governing the hat. Steam turbine governing is the procedure of controlling the flow rate of steam to a steam turbine so as to maintain its speed of rotation as constant. Turbine type of energy head discharge direction of flow specific name type speed pelton. California polytechnic state university, san luis obispo.
The various turbine types have been explained in detail. The wheelshaped rotating blades sandwich the fixed blades. It consists of a stationary circular wheel on which. Require large water ows to produce signi cant powers. Unloaders a typical turbine governing system has two unloaders one activated by low condenservacuum. This turbine is used for medium heads with medium discharge. It is a hydraulic turbine which is used in most of the hydroelectric power plant to generate electricity. It is used to run the turbine at high speed or at low speed or at constant speed can be maintain by the governing is called governor of turbine. Maintenance and overhaul of steam turbines wgp42 05. Of course the quantity is not there, it is not quantitative but it is a qualitative. Turbine type of energy head discharge direction of. When steam strikes the moving blades through nozzles called impulse turbine and when it strikes the moving blades under pressure via guide mechanism called reaction turbine. It is a reaction turbine and therefore only a part of the available head is. Kaplan turbine requires high value of specific speed because it is works on low head.
Steam turbine governing and its mechanism ece tutorials. Kaplan turbine is employed, where a large quantity of water is available. In this case of governing mechanism, the mass flow rate is controlled by throttling the steam by means of control value. Steam turbine governing is the procedure of monitoring and controlling the flow rate of steam into the turbine with the objective of maintaining its speed of rotation as constant. Ppt on francis and kaplan turbine turbine mechanics. Present day practice is to use digital governing control system in hydroelectric units. Oct 21, 2016 on this channel you can get education and knowledge for general issues and topics. Impulse turbine and reaction turbineprinciple, working and. In most of the hydroelectric units reaction turbines are used. Impulse turbine and reaction turbineprinciple, working. Pelton turbine working, main parts, application with diagram. This operates in an entirely closed conduit to tailrace.
The purpose of the governor is to supply steam into the turbine in such a. Before talking about the differences lets see some similarities 1. Kaplan turbine it is an axial flow reaction turbine. Mechanisms governing the high temperature erosion of. Francis turbine works on medium range of specific speed i. In other words, the steam is continually expanding as it flows over the blades. Introduction a turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. In the case of steam turbines, such as would be used for electricity generation, a reaction turbine would require approximately double the number of blade rows as an impulse turbine, for the same degree of thermal energy conversion. In this article, we see about the impulse turbine and reaction turbineprinciple, working and difference. Rocket turbine design emphasizes power density, because of the overriding concern for mass saving. Now after this governing mechanism, i will show you certain characteristic curve of reaction turbine in dimensionless parameters. The basic criteria governing the design of the case on figult. When the load changes, the governing mechanism rotates all the guide blades about their axis through the same angle so that the water flow rate to the runner.
Review of optimal selection of turbines for hydroelectric. Read working principle of impulse and reaction steam turbine. Design and analysis of a split reaction water turbine. The variation in load during the operation of a steam turbine can have a significant impact on its performance. Given a simplified block diagram of a typical turbine governing sys tem, state the function. Pdf power plant lecture notes chapter6 gas turbines. The modern francis water turbine is an inward mixed flow reaction turbine. Turbines are used in boat propulsion systems, hydroelectric power generators, and jet aircraft engines. The hydraulic turbines can be classified based on type of energy at the inlet, direction of flow through the vanes, head available at the inlet, discharge through the vanes and specific speed. Digital controllers used for turbine governing system are very flexible and can be used for functions not directly related to the turbine governing control function. Reaction turbine blading and conditions figure 3 shows, at the top. Steam turbines classification, governing equations and. In the reaction turbine, the steam is expanded in fixed nozzles and also in the moving nozzles. The optimum diameter for a simple reaction turbine is defined and an equation for the optimum diameter is derived.
The steam turbine working principle and theory has been explained in. Steam turbines have a set of rotating blades and a row of fixed half moon blades. Generally the range of specific speed varies from 600. Chaplin encyclopedia of life support systems eolss figure 4. Are you looking for governing mechanism of pelton turbine. The type of hydropower turbine selected for a project is based on the height of standing waterreferred to as headand the flow, or volume of water, at the site. The control value position will be adjusted to allow the required steam for turbine operation. A radial flow reaction turbine consists of the following main components.
Mechanical engineering assignment help, turbines, illustrate governing mechanism of francis turbine. It changes the position of guide blades to affect variation in the water flow rate in the wake of changing load conditions on the turbine. Unesco eolss sample chapters thermal power plants vol. Both turbines produced power due to both kinetic energy and pressure energy. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery. This speed should also conforms to the power supply frequency. In the case of reaction turbine, the moving blades of a turbine are shaped in such a way that the steam expands and drops in pressure as it passes through them. Schematic of impulse and reaction turbines, where the rotor is the rotating part, and. As a result of pressure decrease in the moving blade, a reaction force will be produced. The francis turbine is an inward flow reaction turbine which was designed and developed by the american engineer james b. Specifications tangential flow turbine high head turbine speed and discharge is very less shape of the blade is double hemi sphere efficiency is near about 88% to 98%. Mechanical engineering assignment help, illustrate governing mechanism of francis turbine, a illustrate governing mechanism of francis turbine. The guide vane mechanism along with the governors provides the regulation of the turbine output.
Elec0047 power system dynamics, control and stability. Reaction turbine blading and conditions figure 3 shows, at the top, the end view of four stages of fixed and moving blades of an. Characteristics of francis turbine they operate in a water head from 10 to 650 meters 33 to 2,3 feet. The governor is a control component with advanced protections for the turbine which ensure safe operation of the turbine. So this mechanism acts as a speed governing mechanism of pelton wheel. The runner is a mechanism that converts the hydraulic energy into mechanical power by. Illustrate governing mechanism of francis turbine, mechanical.
Francis turbines it is a reaction turbine developed by an english born american engineer, sir j. Review of existing hydroelectric turbinegovernor simulation. Introduction to francis turbine diagram, working principle the francis turbine is mixed flow reaction turbine. Efficiency, while clearly a consideration, takes a less prominent role than in aircraft turbine design. Write the short notes of governing mechanisms of pelton wheel. Hydraulic turbines are being used from very ancient times to harness the energy stored in flowing streams, rivers and lakes. The flow rate of steam is monitored and controlled by interposing valves between the boiler and the turbine. Pelton turbine is a tangential flow impulse turbine in which the pressure energy of water is converted into kinetic energy to form high speed water jet and this jet strikes the wheel tangentially to make it rotate. So the use of nozzle governing is limited to small turbines. A turbine governor is provided for this arrangement. Steam turbine governing system is a method, used to maintain a constant steady speed of turbine. In another situation, the mechanicalhydraulic governor on l 1500 hp turbine did not control the turbines speed after the teeth on the pump half of a grease lubricated gear coupling, wore down the coupling between the turbine and the pump was a purchasint department special bargain. It covers the governing system and includes working of the woodward governor type.
Understanding and preventing steam turbine overspeeds by. The reaction turbine was invented by sir charles parsons and is known as the parsons turbine. On this channel you can get education and knowledge for general issues and topics. The steam turbine training course has been developed to assist in turbine maintenance and turbine operation.
Department of energy wind and water power technologies office prepared by vladimir koritarov and leah guzowski decision and information sciences, argonne national laboratory james feltes, yuriy kazachkov, baldwin lam, carlos grandemoran. In a pelton turbine or pelton wheel water jets impact on the blades of the turbine making the wheel rotate, producing torque and power. Steam turbine working principle and types of steam turbine. Jun 08, 2018 francis turbine works on medium range of specific speed i. What is steam turbine description and characteristics. The water supplies energy to the runner in both kinetic and pressure forms. Governing of francis water turbine 111520 the major componentsof the governor mechanism are as under. Impulse and reaction blades can be combined to form an impulsereaction turbine. Review of existing hydroelectric turbinegovernor simulation models anldis5 prepared for u. Selecting hydraulic reaction turbines bureau of reclamation. The water enters the turbine through the outer periphery of the runner in the radial direction and leaves the runner in the axial direction, and hence it is called mixed flow turbine. This turbine combines the rotational forces of the previously described turbines. Steam turbine is the widely use as a prime mover in power plants, refineries, petrochemical plants, food processing plants, power plants etc.
Governing of hydraulic turbine free download as powerpoint presentation. It is a reaction turbine and therefore only a part of the available head is converted into the velocity head before water enters the runner. Request pdf experimental study of the mechanism governing the hat humid air turbine cycle performance of a splitshaft micro gas turbine based on a split shaft micro gas turbine and through. The parts of a steam turbine may be thought of as being in four groupings.
Approval issue module 2347 the turbine governing system. It consists of spiral casing, guide mechanism and draft tube of kaplan turbine runner are similar to those of francis turbine. In the reaction turbines two effects cause the energy transfer from the flow to. The methods used for governing of impulse turbines are. Steam turbines may be classified into different categories depending on their construction, working pressures, size and many other parameters. Controls the turbine speed during startup or in no load condition to permit the unit to be synchronized with the grid. The turbine powered generator power output generally ranges from 10 to 750 megawatts. We have already understood that hydraulic turbines are basically defined as the hydraulic machines which convert hydraulic energy in to mechanical energy and this mechanical energy will be given to a generator to produce the electric energy.
Mechanisms governing the high temperature erosion of thermal barrier coatings used in gas turbines article in wear 25678. Water enters the runner and flows towards the centre of wheel in the radial direction and leaves parallel to the axis of the turbine. To find the approximate efficiency for a reaction turbine. Experimental study of the mechanism governing the hat humid. Reaction turbines the potential energy of water is partly converted into pressure. There have been numerous causes of steam turbine failures worldwide. Get details of governing mechanism of pelton turbine. Learn more about design, analysis, working principle and applications of pelton wheel turbine. Oct 18, 2016 on this channel you can get education and knowledge for general issues and topics. Francis turbine working principle, main parts, diagram and. Oct 24, 2016 in this article we will study about the pelton wheel or pelton turbine working, main parts, application with diagram.
Topic governing of francis water turbine prepared byshubham p. The importance of this method is, the turbine can maintain a constant steady speed irrespective of variation of its load. The specific speed is an important factor governing the selection of the. Impulse and reaction blades can be combined to form an impulse reaction turbine.
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