Merchant marine exam third assistant engineer q538. Initially, the reaction turbines rotors are made by. Design development and performance monitoring of split. The turbine rotor, the balance piston, the impulse wheel disc and the subsequent drum parts are. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor.
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. Pdf a cfd analysis of steam flow in the twostage experimental. Difference between cylindrical and salient pole rotor. Are you a person willing to work in industrial sectors then logon to steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Types of steam turbine an overview sciencedirect topics. A velocitycompounded impulse stage consist of a row of fixed nozzles followed by two or more rows of moving blades and fixed blades without expansion. Both classes of machine are similar in stator construction point of view.
Design development and performance monitoring of split micro. This type of turbine makes use of the reaction force produced as the steam accelerates through the nozzles formed by the rotor. A turbine is a turbomachine with at least one moving part called a rotor. This turbine is a single flow type which utilizes the. The efflux angle relative to each row of blades is 70 from the axial direction, the exit velocity of steam from the stator blades is 160ms, the blade speed is 152. Ac 335 turbine engine rotor blade containmentdurability.
A reaction turbine doesnt change the direction of the fluid flow as drastically as an impulse turbine. Schofield ge company schenectady, ny introduction the need to provide stateoftheart products for a diverse and everchanging market is the chal lenge facing steam turbinegenerator manufactur ers in the 90s. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Steam turbines are one of the most versatile and oldest prime mover technologies still in general production used to drive a generator or mechanical machinery. Other deciding factors include how deep the turbine must be set, efficiency, and cost. The blade type best suited for this type of turbine is impulse blading, whereby the pressure drop is kept at a minimum. If an impulse turbine is a bit like kicking soccer balls, a reaction turbine is more like swimmingin. Feb 10, 2017 one of the primary reasons for an impulse type steam turbine to have discs is that pressure balancing across its moving blades.
Gas turbine blades are made of nickelbase and cobaltbase super alloys principally. In hp and ip turbine sections, the reaction type of turbine is favored for its high efficiency. These rotors are not too common in the uk, where they have been applied to lp turbine rotors. In a parsons reaction turbine the rotor blades are similar to the stator blades but with the angles measured in the opposite direction. In the above setup, water is pumped to the turbine, via a pipe. Unfortunately, there is still not enough data which would permit an evaluation of the effectiveness of one or the other method of moisture separation. Ger3646d steam turbines for large power applications. This evolution is a balanced integration of economic, aerodynamic, structural dynamic, noise, and aesthetic considerations, which are known to be machine type and size dependent.
Evolution of d series cc steam turbine r3 ge steam. The diffuser scoop is able to remove liquid from the rotor and convert the kinetic energy of the rotating fluid. Design solutions that limit a turbine engines rotor overspeed in an event of shaft failure, are shown in table 1. Impulse turbine efficiency calculation methods with organic. Impulse turbine and reaction turbine nuclear power.
One of the primary reasons for an impulse type steam turbine to have discs is that pressure balancing across its moving blades. Instead, the blades that project radially from the periphery of the rotor are formed and mounted so that the spaces between the blades have, in cross section, the. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Initially, the reaction turbines rotors are made by solid forged drum type rotor. In a reaction turbine, the blades sit in a much larger volume of fluid and turn around as the fluid flows past them. Pdf power plant lecture notes chapter4 steam turbine. Ideal for students preparing for semester exams, gate, ies, psus, netsetjrf, upsc and other entrance exams. Drum type rotor manufactured from solid or hollow forgings fig 1.
Reaction turbine the reaction turbine, as the name implies, is turned by reactive force rather than by a direct push or impulse. Due to the density difference, the gas phase accelerates more rapidly than the liquid. The static blade assembly has a radially inner static ring. The work produced by a turbine can be used for generating electrical power when combined with a generator. Micro hydro reaction turbine by varying the number of nozzles. The rotor design is based upon advanced calculation. What is awhat is a turbineturbine a turbine is a rotary mechanical device that extracts energy from a fast moving flow of water, steam, gas, air, or other fluid and converts it into useful work.
The pressure of the gas or fluid changes as it passes through the turbine rotor blades. Paper open access prevention of hazardous failure of the. The weightsaving concepts employed in the design of the turbine rotor assembly resulted in a weight reduction of of, of. Franceis and are used for medium head45400 m and medium discharge. The turbine rotor, the balance piston, the impulse wheel disc and the subsequent drum parts are integral forgings of high temperature material. With this blade type, the ratio between absolute blade velocity and incoming gas velocity ranges from 0. The crossflow turbine has a drumlike rotor with a solid disk at each end and guttershaped slats joining the two disks. The flow is thereby accelerated and directed to the rotor through which it is diverted while. The separating turbine uses a diffuser scoop for liquid removal to pressurize the liquid and to prevent gas carryunder. Impulse turbine efficiency calculation methods with. Early turbine examples are windmills and waterwheels.
The shape of the blades is such that on each passage through the. Instead, the blades that project radially from the periphery of the rotor are formed and mounted so that the spaces between the blades have. Steam turbines are used as parts of stationary and transport marine steam turbine power units. A drum type rotor carries an annular row of moving blades having root portions held within a slot in the periphery of the rotor. The principle of performing field balancing is to make usually tempo rary alterations to the mass distribu tion of the rotor, by. Generally, multistage steam turbines of reaction type fig. Turbine components rotor disks, blades, blade attachments are heavy duty components which can be classified as critical components. The reason for doing one versus the other can be many.
Application notes static and dynamic balancing of rigid. Our fuelless engine can do the job or a solar panel can be used to run a high efficiency dc fan motor, which will start the atomic reaction. In general, the cylindrical rotor type machines are confined to 2 and 4 pole turbine generators, while salient pole types are built with 4 poles upwards and include most classes of. Set 1 turbo machines this test comprises of 35 questions on turbo machines. To overcome this nowadays the hollow drumtype rotors are used instead of solid rigid rotors. Merchant marine exam third assistant engineer illustrations. Once comstructed, rightclick on the steam turbine and insert a turbine rotor. Develop the rotor internal spacing for the welded drum type rotor by allowing for spaces between t he drums consisten t with ex isting des igns. The rotor blades of the last rows are grouped by means of damping and binding wires. It degrades very slowly, and can output millions of eu before needing to be replaced. If reducing weight is of paramount interest, discrete rotor disks may be favored. Why rotors of reaction steam turbines are built as drum.
Dec 16, 2004 0017 the at least one impulse turbine stage may be combined with at least one reaction turbine stage on a common drum type rotor, the impulse and reaction stages having the same inner diameter of their turbine flow annulus and the drum rotor having the same, or substantially the same, outside diameter along its axial length. A drumtype rotor carries an annular row of moving blades having root portions held within a slot in the periphery of the rotor. In this type, the total pressure drop expansion of the steam take place only in the first nozzle ring. Reactiontype turbines are constructed in a drum type design. Turbine rotors can either be built as discrete wheels disks or drumtype rotors, as you suggested. Speed is relative low up to 6000 rpm, except for special design up to 12000 rpm. During the past few decades, the operating temperatures of gas turbine engines have been on the rise to achieve higher and higher.
Feb 10, 2015 francis turbine the francis turbine is a type of water turbine that was developed by james b. Paxson nasa lewis research center 2 brookpark road, mis 776 cleveland, oh 445 abstract the benefits of wave rotortopping in small 400 to 600 hpclass and intermediate 3000 to 4000 hpclass turboshaft engines, and large 80,000 to 100,000 lb. Provides guidance and acceptable methods, but not the only methods, that may be used by an applicant in showing compliance with the turbine engine rotor blade containment requirements of part 33 of the federal aviation regulations far. The turbine is placed in a housing to avoid turbine. Ger3705 ge steam turbine design philosophy and technology. A lowpressure steam turbine rotor for mw class power plants becomes a large rotor of more than 500 ton in its ingot weight. Pdf the aim of the paper is to present the cfd analysis of the steam flow in the twostage turbine with a drum rotor and balancing slots. The turbine rotors, the balance piston and the impulse wheel disc, as well as the subsequent drum parts, are a solid forging of high. Hpip inner casings, packings and rotors renewed to accommodate changes. Otc 218 field test results of a rotary separator turbine on. Reaction turbine rankine cycle ipsv1 ipcv 1 from rh. Our fuelless engine can do the job or a solar panel can be used to run a high efficiency dc.
Twophase nozzles the inlet nozzles convert the pressure energy of the twophase flow mixture into kinetic energy. This type of turbine can be employed for two or threephase separation. The gas initially drives the liquid hydrogen pump turbine, then it is further expanded to feed the liquid oxygen turbopump turbine. In the drum rotor configuration, the space for interstage root seal is very limited.
A turbine from the latin turbo, a vortex, related to the greek, tyrbe, meaning turbulence is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. Initially, the reaction turbines rotors are made by solid forged drum. Steam is directed onto the rotor by the fixed vanes of the stator. Francis turbine the francis turbine is a type of water turbine that was developed by james b.
Therefore from the literal meaning of saliency one can guess that salient pole machines must have poles projecting outward. Spe 63039 design and analysis of a multiphase turbine for. Steam turbine rotors may be disktype or drumtype, disktype rotors are used in impulse turbines see turbines, dramtype rotors are used in reaction turbines. As you may be aware, in a particular stage of an impulse turbine, pressure drop happens only across the diaphragm and n. Steam turbine operating range the following criteria are used for selection steam turbine type 3. In reaction turbines, there are no nozzles as such. Francis turbine, a type of widely used water turbine. Due to this, the inertia of the rotor is very high when compare with the disctype rotor of the same capacity. Normally the forged rotor weight is around 50% higher than the final machined rotors. A jet of water enters the top of the rotor through the curved blades, emerging on the far side of the rotor by passing through the blades a 2nd time. This type of rotor is largely used in steam turbines. Steam turbine basic parts mechanical engineering site. Impulse and reaction technologies ges d series combined cycle steam turbine designs incorporate both impulse and reaction technologies. Modern steam turbines frequently employ both reaction and impulse in the same unit.
A admit astern steam to the turbine after securing the ahead steam o b tighten the stern tube packing gland o c apply the prony brake o d secure all steam to the turbine. Drum rotor construction is typical for the reaction type of steam turbine. In the case of singleflow reaction turbines, a balance piston is equipped to cancel the thrust force produced by the pressure drop in the moving blades fig. The reactiontype steam turbine has a drumtype rotor, and stationary blades are either installed in a stationary blade holder, or welded in a stationary blade ring. Turbine rotors are classified as a disktype rotor and a drum type rotor from the viewpoint of configuration. Rotordynamic analysis of the am600 turbinegenerator shaftline. Overseas applications have included hp and ip turbine rotors. In the case of singleflow reaction turbines, a balance piston is equipped to cancel the thrust force produced. In order to get a prior idea about the probable difficulties that may arise during fabrication of the test rig, a 3d solidmodel fig 7 of the setup was made. The definition of an impulse turbine is that the majority of the fluid expansion takes place in the fixed turbine stators. A turbine casing surrounds the rotor and carries a static blade assembly with an annular row of static blades which, together with the annular row of moving blades, constitutes an impulse turbine stage. This is in contrast to the major alternative technology of reaction stage design with a drumtype rotor and related construc tion features. Apr 25, 2018 in general, the cylindrical rotor type machines are confined to 2 and 4 pole turbine generators, while salient pole types are built with 4 poles upwards and include most classes of duty.
A rotor is balanced by placing a cor rection mass of a certain size in a posi tion where it counteracts the unbal ance in the rotor. The crossflow turbine has a drum like rotor with a solid disk at each end and guttershaped slats joining the two disks. The objective of this paper is to provide a historical perspective of the evolution of rotor and blade design during the last 20 years. The at least one impulse turbine stage may be combined with at least one reaction turbine stage on a common drumtype rotor, the impulse and reaction stages having the same inner diameter of their turbine flow annulus and the drum rotor having the same, or substantially the same, outside diameter along its axial length. This divides the velocity drop across the stage into several smaller drops. Steam turbine interview questions are you a person with a degree in mechanical or technical engineering. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum. The reaction turbines are designed with a forged drum type rotor. A admit astern steam to the turbine after securing the ahead steam o b tighten the stern tube packing gland o. Otc 218 field test results of a rotary separator turbine. A method for making a drum rotor useful in a gas turbine engine having an axis of rotation, and comprising a first disk, a second disk, and a seal therebetween, the seal comprising a first annular seal subdetail and a second annular seal subdetail, wherein the disks have a superalloy composition different from the seal subdetail alloy composition, the method comprising the steps of. Most drum rotors have a spacer or knife edge labyrinth seal between adjacent rotor stages disks. Drum rotors are well known in the gas turbine engine industry. Initially, the reaction turbines rotors are made by solid forged drumtype rotor.
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