Steam turbines are used for a large marine propulsion. Two independent mechanisms, known as governors, are used to ensure safe operation of. Unit iii unit iii steam nozzles and turbines flow of steam through nozzles, shapes of nozzles, effect of friction, critical pressure ratio,supersaturated flow. It is very useful for all kind of gate, ssc, ese and other competitive examinations. A single stage impulse turbine with a diameter of 1.
Lp exhaust spray cooling system function and system layout. Converging nozzle for highpres per mwh and costing as much as sure hp. The most widely used and powerful turbines of today are those that run on steam. By analyzing the results between nozzles 5, 6, 7 and 8, we. Steam at high temperature and high pressure but relatively low speed enters into the nozzle. The influence of nozzle clearance on the flow field for a variable nozzle turbine, and moreover on the turbine stage performance was numerically investigated. Mar 07, 2015 vanita thakkar bit 51 factors affecting nozzle effeciency nozzle type velocity coefficient roughly cast nozzles 0. The magnitude of each component was determined as 1.
Pj10 misting nozzles at 2900 psi 200 bar, to reach the estimated 4. Modification of nozzles for the improvement of efficiency of. A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to. Steam nozzles and turbines online practice test set 10 mcq steam boilers edit practice test. The fluid power is converted into kinetic energy in the nozzles. Steam turbines are not only employed to operate electric generators in thermal and nuclear power plants to produce electricity, but they are also used a to propel large ships, submarines and so on, and b to drive power absorbing. This highvelocity steam hit the properly shaped turbine blade, as a result. Its modern manifestation was invented by charles parsons in 1884 the steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of. The basic element in a turbine is a wheel or rotor with addles, propellers, blades, or buckets arranged on its circumference in.
Hello, for sometime now ive been into electronics and i have forgotten most of my meager knowledge in thermodynamics. Since the turbines are adequately insulated the surface heat loss by convection and radiation is small. What are the effects of friction on the flow through a steam nozzle. Mechanical engineering steam nozzles and turbines online. In an ocean liner or a jet, hot burning gas is used to spin metal blades at high speedcapturing energy thats used to. Now we will see another modification of the rankine cycle which is very commonly used in practical steam power plant. We can also deliver, install and maintain all energy equipment we sell. Mechanical engineering online mock test for mechanical engineering steam nozzles and turbines topic.
This paper introduces the wind power generator using horizontal axis wind turbine with convergent nozzle. A dropin nozzle block 40 formed in two 180 segments 52 that can be simply lowered into position within the nozzle chamber casing of a steam turbine 42. In this section you can learn and practice mechanical engineering questions based on steam nozzles and turbines and improve your skills in order to face the interview, competitive examination and various entrance test cat, gate, gre, mat, bank exam, railway exam etc. In a sandcastle windmill, the curved blades are designed to catch the winds energy so they flutter and spin. Why is a nozzle used only impulse turbines, and not in. Today were going to concentrate on nozzle block and blade inspections in high pressure hp steam turbines through access from a removed control or governor valve. For water, at pressures below atmospheric, a melting point rises slightly and boiling point drops markedly b melting point rises markedly and boiling point drops markedly c melting point drops slightly and boiling point drops markedly d melting point drops slightly and boiling point.
The moving blades of reaction turbines do have a change in flow area. There is only one value of the ratio p2p1, which produces maximum discharge from the nozzle. Purpose this manual can be used for preliminary selection, steam and cooling water planning for steam turbines in basic and detail engineering stages. The steam inlet nozzles are arranged in several groups with all but the main group having control valves.
Pdf study on valve management of deh for steam turbine. Definition a steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft. The present report discusses the mode of operation of supersonic nozzles for such turbines, and describes a cascade experiment. A inherent moisture and surface moisture are different things b. A steam turbine is basically an assemblage of nozzles and blades. Operation and maintenance schedule of a steam turbine. The velocity through a nozzle is a function of the pressuredifferential across the nozzle. Mechanical and electrical thermal engineering steam nozzles and turbines. Reaction turbine the reaction turbine, as the name implies, is turned by reactive force rather than by a direct push or impulse. Crossflow turbines for smallscale remote power in developing countries are cheap but usually less efficient than other turbines.
Mechanical engineering steam nozzles and turbines online test. The available energy of steam is first changed into kinetic energy, and this kinetic energy is then transformed into mechanical work. Turbine is a rotary engine that converts the energy of a moving stream of water, steam, or gas into mechanical energy. Operation and maintenance schedule of a steam turbine plant. Nozzle is a duct of varying crosssectional area in which the velocity increases with the corresponding drop in pressure. Lp exhaust spray cooling system function and system. What are the various types of nozzles and their functions. Why mechanical engineering steam nozzles and turbines. Since then turbines based on these principles have evolved in parallel and in fact merged to some degree. Steam nozzles a steam nozzle is a passage of varying resection, which converts heat energy of steam into kinetic energy as the steam expands from higher pressure to lower pressure. They are only used for high heads from 60 m to more than 1 000 m.
Wind power generator using horizontal axis wind turbine with convergent nozzle. In reaction turbines, there are no nozzles as such. A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Could you explain how a convergentdivergent nozzle works. Steam boilers, engines, nozzle, turbines mechanical mcqs pdf. To supply high velocity jet of steam in steam turbine. Pdf effect of nozzle geometry on a model thermocompressor. They do not therefore change the velocity of the steam but only change its direction. It provides an oil film it removes heat generated in the bearings. In this way the power produced by the turbine can be varied. The moving blades of impulse turbines do not have a change in flow area.
Modification of nozzles for the improvement of efficiency. Steam nozzles and turbines free lecture notesgiven below download free lecture notes pdf linki download free lecture notes pdf linkii download free lecture notes pdf linkiii download free lecture notes pdf linkiv download free lecture notes pdf linkv download free lecture notes pdf linkvi download free read more. They also have steam inlets usually a set of nozzles and outlets. Steam turbine types steam turbine types based on blade geometry and energy conversion process are. During the lowload running of a turbinegenerator unit, the volume of steam flowing through the last row of the lp turbine blades is reduced considerably and the smooth aerodynamic flow of steam through these blades is lost. Both theory and experiment demonstrate that the conditions imposed upon the supersonic flow immediately downstream. Steam boilers, engines, nozzles and turbines set 01 mcq steam boilers edit practice test. The axes of the nozzles are in the plan of the runner. The condensate supply, before reaching the spray nozzles in each end of the lp turbine cylinder exhaust, normally passes through a manual isolating valve, a pressure reducing valve, a strainer to remove dirt particles, a flow indicating switch measuring water flow to sprays and a pneumatic flow control. They are shaped like nozzles and act to accelerate the steam as it passes through them. Some modern methods are used to improve the turbine efficiency. Ratio of actual exit velocity to the exit velocity when the flow is isentropic between the same pressure. A new analytical nozzle design methodology is presented based on converting the head to kinetic energy at the runner entry. For water, at pressures below atmospheric, a melting point rises slightly and boiling point drops markedly b melting point rises markedly and boiling point drops markedly c melting point drops slightly and boiling point drops markedly.
The area of crosssection should therefore, be constant at all points. All nozzles consist of an inlet section, a throat, and an exit. Because a very small drop size was needed, twentyone 21. From nuclear reactors to thermal power plants, the role of the steam turbine is both pivotal and result determining. Flow nozzles flow solutions for steam in the power for. Instead, the blades that project radially from the periphery of the rotor are formed and mounted so that the spaces between the blades. The performance of steam turbine efficiency can be discussed with the help of its internal efficiency characteristics.
Steam turbine problems and their field monitoring jonas inc. Feb 21, 2008 hello, for sometime now ive been into electronics and i have forgotten most of my meager knowledge in thermodynamics. Nozzle is the stator part of turbine means it is fixed part. In turbines there are basically 2 part one is called rotor and another is known as stator. Pelton turbine or wheel is an impulsive turbine used mainly for high head hydroelectric schemes. Only two fans will be operated at a time, needing 42 of the bete. Impulse turbines do not require a pressure casement around the rotor since the fluid jet is created by the nozzle prior to reaching the blades on the rotor. Two independent mechanisms, known as governors, are used to ensure safe operation of the turbine. To inject feed water in to the boiler in a steam injector. 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. Vanita thakkar bit 51 factors affecting nozzle effeciency nozzle type velocity coefficient roughly cast nozzles 0.
A steam turbine is basically an assembly of nozzles fixed to a stationary casing and rotating blades mounted on the wheels attached on a shaft in a rowwise manner. Cruising turbines of the y100 naval propulsion machinery pdf. Turbine blades are of two basic types, blades and nozzles. Steam boilers, engines, nozzles and turbines set 01. Steam turbine and steam nozzle interview question and. Impulse and reaction principles, compounding, velocity diagrams for simple and multistage turbines, speed regulationsgovernors and nozzle governors. The steam from the boiler is expanded in a nozzle, resulting in the emission of. Bete turbine cooling nozzles pj misting nozzles for turbines. Pdf on apr 10, 2012, kavous ariafar and others published effect of nozzle geometry on a model. Steam boilers, engines, nozzles and turbines questions. For water, at pressures below atmospheric, a melting point rises slightly and boiling point dro steam boilers, engines, nozzles and turbines questions and answers pdf free download for freshers and experienced mechanical engineering students. Because the length of the inlet steam piping can vary from 20 over 80 in length, this application requires a special, long, articulating videoscope. Now we will discuss how to improve steam turbine efficiency as well as the power developed by the turbines. Rotor means which part rotate and stator means which part is fixed.
What are the effects of friction on the flow through a. Which is not the correct statement about moisture in coal. Pj10 misting nozzles were used for each of the three fans. Wind power generator using horizontal axis wind turbine. Steam boilers, engines, nozzles and turbines mechanical. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Flow nozzles flow solutions for steam in the power industry, including acceptance testing for steam turbines. The basic parts of stream turbines are blades and rotors. The mechanical engineering full online mock test paper is free for all students and very helpful for exam preparation.
This manual does not for designing steam turbine and the related parts. Each jet issues water through a nozzle with a needle valve to control the flow figure 6. Calculate turbine efficiency improve steam turbine. As a result of increased steam velocity steam pass through the nozzle in the form of a highspeed jet. A new nozzle design methodology for high efficiency. Aug 31, 2014 steam boilers, engines, nozzles and turbines questions and answers pdf 1. An entire 180 segment can be lowered into position because an inner arcuate portion 58 of the nozzle block fits over and captures mating portions of the casing rather than. Steam boilers, engines, nozzles and turbines mechanical engineering test 1 fire tube boilers are those in which a water passes through the tubes and flue gases surround them. There are some energy losses in the bearings and governing mechanisms which can be reduced by improving the lubrication system. Impulse turbine and reaction turbineprinciple, working. Strength of materials objective questions with answers set 10. Steam boilers, engines, nozzles and turbines questions and answers pdf 1.
Mechanical engineering question and answers in english. Automobile engineering important multiple choice questions with answers pdf file fr. Steam nozzles and turbines online practice test set 10. Mar 14, 2019 mechanical engineering steam nozzles and turbines online test. A new nozzle design methodology for high efficiency crossflow. A convergent divergent adiabatic steam nozzle is supplied with steam at 10 bar and 250c. Herewith we have shared the steam boilers, engines, nozzle, turbines mechanical mcqs pdf mechanical engineering multiple choice questions and answers pdf. Proenergy has a large inventory of energy parts and complete packages. The pelton wheel is among the most efficient types of water turbines.
Jan 02, 2017 in turbines there are basically 2 part one is called rotor and another is known as stator. Both impulse and reaction turbines have steam inlet nozzles. The steam at high pressure enters through a stationary nozzle of a steam turbine, as a result the pressure of the steam is decrease and an increase in steam velocity. Purpose to produce high velocity jet of steam to run in steam turbines. Modification of nozzles for the improvement of efficiency of pelton type turbines by matthew gass, hetch hetchy water and power, moccasin ca usa abstract the latest units in a program of turbine upgrades and efficiency improvements fell short of the expected efficiency after modification. There is a reason why nozzles are not required for reaction turbines. Pelton turbines are impulse turbines where one or more jets impinge on a wheel carrying on its periphery a large number of buckets.
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