The impulse turbine is composed of moving blades alternating with fixed nozzles. Impulse turbine and reaction turbine nuclear power. Governing of impulse turbines free download as pdf file. It covers the governing system and includes working of the woodward governor type. California polytechnic state university, san luis obispo. The pelton wheel is among the most efficient types of water turbines. The design data are taken from wattwon hydropower in pyin oo lwin, myanmar. The pressurevelocity compounding is a combination of the above two types of compounding.
Comparison between impulse turbine and reaction turbine. Pelton turbine is a tangential flow impulse turbine in which the pressure energy of water is converted into kinetic. Impulse stages may be either pressurecompounded, velocitycompounded, or pressurevelocity compounded. Unloaders a typical turbine governing system has two unloaders one activated by low condenservacuum. This practice is still commonplace today in marine steam. Automatic generation control and monitoring the mechanism of micro hydro power plant with impulse turbine and synchronous generator conference paper pdf available november 2016 with 874 reads. Impulse turbine works on the basic principle of impulse. Jun 08, 2018 francis turbine works on medium range of specific speed i. In this method the steam flow is regulated by opening or closing some set of nozzles of the turbine.
Before talking about the differences lets see some similarities 1. Difference between impulse and reaction turbine impulse turbine reaction turbine 1. Understanding and preventing steam turbine overspeeds by. Oct 20, 2016 on this channel you can get education and knowledge for general issues and topics. The buckets are so shaped that water enters tangentially in the middle and discharges backward and flows again tangentially in both the direction to avoid thrust on the wheel as shown in the line sketch. Steam turbines classification, governing equations and.
This turbine combines the rotational forces of the previously described turbines. Steam turbine governing system is a method, used to maintain a constant steady speed of turbine. There are two basic types of turbines according to the mode of steam. Governing system of gas turbine control theory throttle. Pelton turbine used for large water heights 300 m or more 31. The runner is a mechanism that converts the hydraulic energy into mechanical power by. H thakkar3 1,2,3assistant professor 1,2,3department of mechanical engineering 1,2,3sankalchand patel college of engineering, visnagar, gujarat n. This turbine used to rotate the generator, which produces electric power. On this channel you can get education and knowledge for general issues and topics. Impulse and reaction turbine are compared below presented in picture and tabular form. Governing mechanism of pelton turbine pdf runner with bucket. Steam turbines have a set of rotating blades and a row of fixed half moon blades. Impulse turbine efficiency calculation methods with. 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.
Ed nelson is a tu rbo machinery consultant based in dickinson, texas. Unesco eolss sample chapters thermal power plants vol. Impulse turbines change the direction of flow of a high velocity fluid or gas jet. The steam turbine working principle and theory has been explained in. 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. Dahlqvist approved 20121016 examiner damian vogt supervisor jens fridh commissioner contact person 1 abstract a turbine was investigated by various methods of calculating its efficiency. Specific speed, governing and limitations of impulse turbine. The guide vane mechanism along with the governors provides the regulation of the turbine. Okay we have discussed pelton wheels first, that is the impulse flow turbine, purely. When the jet of water strikes at the turbine blade with full of its speed, it generates a large force which used to rotate the turbine. Iet institute for energy technology 556,784 views 10. Francis turbine works on medium range of specific speed i.
A pelton turbine develops 2000 kw under a head of 100 m and with an overall. A water turbine is a rotary machine that converts kinetic energy and potential energy of water. Now in reaction machines, this is done by this mechanism, i will show you. Standard deviation for compressive strength of concrete with example pdf.
Pelton turbine among different types of impulse turbines, pelton wheel is the only turbine being used at. Gas turbine governing dynamics and control systems. This pdf explains in details about the different types of governing systems being used in gas turbines. The variation in load during the operation of a steam turbine can have a significant impact on its performance. Governing of hydraulic turbine free download as powerpoint presentation. The specific speed is an important factor governing the selection of the. 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 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. Steam turbine governing and its mechanism ece tutorials. Steam turbine governing is the procedure of controlling the flow rate of steam to a steam turbine.
It operates under v ery high heads upto 1800 m and requires comparatively lesser quantity of water. Turbine parameter impulse turbine reaction turbine steam pressure decreases in every nozzle. Impulse turbine basic mechanical engineering benchmark ktu duration. Reaction turbine blading and conditions figure 3 shows, at the top. Approval issue module 2347 the turbine governing system. Write the short notes of governing mechanisms of pelton wheel. The parts of a steam turbine may be thought of as being in four groupings. In an impulse turbine, all the energy available by water is converted into kinetic energy by passing a nozzle. Pdf power plant lecture notes chapter6 gas turbines.
This is why we call this type of turbine as impulse turbines. The flow energy to the impulse turbines is completely converted to kinetic energy before. Turbines a turbine is a rotary engine that exerts energy from a fluid flow and converts it into useful work. Action or impulse type turbines the potential energy of water is converted into pressure and then into kinetic energy by passing through nozzles. Efficiency, while clearly a consideration, takes a less prominent role than in aircraft turbine design.
Different parts and their functions of pelton turbine are as follows. Being impulse turbine it must run at atmospheric pressure a nd therefore, these are located above the tail race. The various turbine types have been explained in detail. Oct 21, 2016 on this channel you can get education and knowledge for general issues and topics. Many earlier variations of impulse turbines existed, but they were less efficient than peltons design. The turbine in the operation can be either driven by principle of reaction mechanism or impulse mechanism.
If francis turbine is run below 50 percent head for a long period it will not only lose its efficiency but also the cavitation danger will become more serious 4. Both turbines produced power due to both kinetic energy and pressure energy. 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%. Understanding and preventing steam turbine overspeeds by william e. Impulse and reaction blades can be combined to form an impulsereaction turbine. 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. The modern demonstration of turbine was invented by sir charles parsons in 1884. It is the most renowned example of impulse turbine. It was discovered in 188 0 by an american engineer lestera. The impulse generated in this procedure is used to provide the momentum to the blades. The word turbine has been derived from the greek word tyrbe which has the meaning turbulence.
In principle, the impulse steam turbine consists of a casing containing stationary steam nozzles and a rotor with moving or rotating buckets. Hydraulic turbines are being used from very ancient times to harness the energy stored in flowing streams, rivers and lakes. Schematic of impulse and reaction turbines, where the rotor is the rotating part, and. Impulse turbine efficiency calculation methods with organic. Kaplan turbine requires high value of specific speed because it is works on low head. Turbine speed governing system plz use speakers duration. It consists of a stationary circular wheel on which. Pelton turbine parts, working and design aspects the constructor. The pelton wheel extracts energy from the impulse of moving water, as opposed to waters dead weight like the traditional overshot water wheel. The importance of this method is, the turbine can maintain a constant steady speed irrespective of variation of its load. Pelton turbine among different types of impulse turbines, pelton wheel is the only turbine beingused at present. Impulse turbine and reaction turbineprinciple, working. What is the difference between an impulse and a reaction.
Explain parts and working principle of pelton turbine with neat sketch. Read working principle of impulse and reaction steam turbine. Action or impulsetype turbines the potential energy of water is converted into pressure and then into kinetic energy by passing through nozzles. Types of governing mechanisum for impulse turbine 1needle wheel rod. Governing system of gas turbine free download as powerpoint presentation. The fluid power is converted into kinetic energy in the nozzles. If you do not add any mechanism to changed the driving torque, the speed of the rotor will. The steam turbine training course has been developed to assist in turbine maintenance and turbine operation. The high velocity jet coming out of the nozzle then impinges on a series of buckets fixed around the rim of a wheel. Governing of impulse turbines jet engine turbine scribd. The force is depends on the time interval and velocity of jet strikes the blades. He retired fro m amoco oil company, after more than 36 years in. Nelson turbomachinery consultant dickinson, texas and perryc. In fact, a series of velocitycompounded impulse stages is called a pressurevelocity.
Impulse turbine efficiency calculation methods with organic rankine cycle johan e. With a poor governing system, these smaller, less abrupt, load changes can still result in. Steam turbine working principle and types of steam turbine. Reaction turbine 2 iii steam turbine operating range 2 3. Pelton turbine or wheel is an impulsive turbine used mainly for high head hydroelectric schemes. G, india abstracta peltonwheel impulse turbine is a hydro. When the steam passes through the stationary nozzles and is directed at high velocity against the rotor buckets. Later, impulse turbines were developed which didnt use swirl. Learn more about design, analysis, working principle and applications of pelton wheel turbine. In the reaction turbine, first the steam flows through the guide mechanism.
Turbine is a machine which uses the kinetic energy of fluids and transforms into mechanical energy through a designed mechanism. Rocket turbine design emphasizes power density, because of the overriding concern for mass saving. So this mechanism acts as a speed governing mechanism of pelton wheel. One of the most popular example of impulse turbine is pelton wheel. Low initial cost and simple mechanism makes throttle governing the most apt method for small steam turbines.
Steam turbine 1 content chapter description page i purpose 2 ii steam turbine types 2 2. A pelton wheel is an impulsetype water turbine invented by lester allan pelton in the 1870s. Each bucket reverses the flow of water and this impulse spins the turbine. 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. Schematic diagram summarising the differences between impulse turbine and reaction turbine, where the rotor is the rotating part and the stator is the stationary part of the machine. Chaplin encyclopedia of life support systems eolss figure 4. This type of governing is suitable for simple impulse turbine and most efficiently in part load conditions.
The methods used for governing of impulse turbines are. The flow rate of steam is monitored and controlled by interposing valves between the boiler and the turbine. Water leaving those wheels typically still had high. In impulse turbine the steam flows through the nozzle and strike on the moving blades. Specific speed governing and limitations of impulse turbine nptel. Generally the range of specific speed varies from 600. The wheelshaped rotating blades sandwich the fixed blades. Impulse turbine and reaction turbineprinciple, working and. This paper is to design the pelton turbine, its regulating mechanism and speed control system that can develop a power output of 225 kw. Pdf automatic generation control and monitoring the. Review of optimal selection of turbines for hydroelectric. Curtis turbine, rateau turbine, or browncurtis turbine are impulse type turbines. In the impulse turbine, the steam is expanded in fixed nozzles and remains at constant pressure when passing over the blades.
The pelton turbine is a tangential flow impulse turbine. In this article, we see about the impulse turbine and reaction turbine principle, working and difference. Use of a small section of a curtis arrangement, typically one nozzle section and two or three rows of moving blades, is usually termed a curtis wheel and in this form, the curtis found widespread use at sea as a governing stage on many reaction and impulse turbines and turbine sets. Pressurevelocity compounding curtis turbine curtis turbine pressurevelocity compounding. The highvelocity jets of water hit spoonshaped buckets on the runner. Steam turbine is the widely use as a prime mover in power plants, refineries, petrochemical plants, food processing plants, power plants etc. Apr 25, 2016 impulse turbine works on the basic principle of impulse. Differences between francis and kaplan turbines mech4study. This speed should also conforms to the power supply frequency. Impulse turbines rotate due to the impact of fluid over the blade, thus rotating the hub. Comparison between throttling and nozzle governing mechanisms. In this paper, the turbine used for hydropower plant is the pelton turbine which is one of the impulse turbines. Elec0047 power system dynamics, control and stability.