Steam nozzles nptel pdf merge

The steam should be dry and saturated, unless the system specifi. By following one or more of the steps from a to d given above and steps e and f given below, such nozzle loads can be reduced. It does not cover the use of nozzles and venturi nozzles in pipe sizes less than 50 mm or more than 630 mm, or for pipe reynolds numbers below 0. Steam issuing out from the nozzles meets the leading edges of the blades and energy may be lost if the entry is not smooth enough and eddies are formed. The difficulties are eliminated by milling or otherwise machining the nozzles into a.

Steam boilers engines nozzles and turbines mechanical. A suitable test technique using a closedjet tunnel is demonstrated. Introduction, intake efficiency, nozzle efficiency duration. Steam nozzle steam nozzle objective type questions and answers. In this paper by changing the angle of the nozzles, the efficiency of the turbine calculated in terms of nozzle angle. But in order to find the critical pressure ratio critical velocity maximum mass flow rate, approximate formulae may be used. To decide if you need the blank or flat nozzle you need to analyze the job its for. A source of dry steam at or slightly above design pressures must be available at the ejector nozzles at all times. Calculate base dimensions of the nozzle and state of water steam at the exit. Twodimensional kinetics tdk computer program, which has been combined with a boundary layer module blm, is the industry standard jannaf joint. There is a reason why nozzles are not required for reaction turbines. Steam nozzles and engines mechanical engineering questions. Steam ejector is an important component in engineering applications, which require high. Pipe flow measurement flow nozzles iso 51673, bs 10421.

Sep 06, 2015 steam nozzle properties of steam can be obtained from tables or from hs chart. The single nozzle, fixed orifice is the simplest type of ejector. Here the distance between plate and nozzle is constantly increasing by u ms. Rankine cycle, steam generators and their accessories, performance of boilers and combustion of fuel, high pressure boilers, flow through steam and gas nozzles, different type of steam turbines for power generation and.

Numerical study on condensation process of steam flow in nozzles. In this nozzle the cross sectional area gradually decreases from the entrance area to the minimum area which is the exit. Pp ea for less e, e t a pp a a, could derive more forward push by. Recent failures with flow nozzles are associated with using a stainless nozzle inside a p91 pipe. Lecture series on steam and gas power systems by prof. Steam encounters these losses in the blade passages, which depends on the roughness of the blade surface. It is not applicable to the measurement of pulsating flow. By steady flow energy equation between sections 1 and 2. Nozzle governing of steam turbine with inner architecture for example if the turbine consists of 10 nozzles for full power100 %. The nozzles are designed for lowest operating pressure ratio between nozzle throat and exit. The mass flow rate of water steam must be 0,3 kgs1. Subcritical and supercritical boilers, fluidized bed boilers, firetube and watertube boilers, mountings and accessories week 5. The project on development of remaining three quadrants to nptel phasei under grant in aid nmeict, mhrd, new delhi.

If steam at high pressure is allowed to expand through a stationary nozzle, the result will be a drop in the steam pressure and an increase in steam velocity. Steam nozzle steam nozzle objective type questions and. Both the conventional conventional bell and unconventional aerospike and expansiondeflection nozzles can be the subject of consideration of the moc. Impulse and reaction stage, degree of reaction, velocity triangle, week 6. The heat energy required for steam generation is produced by burning fuel in the furnace. The main use of steam nozzle in steam turbines is to produce a jet of steam with a high velocity. Depending on the condition of the steam either the curve for saturated. Nozzle is a duct by flowing through which the velocity of a fluid increases at the expense of pressure drop. Assume friction loss in the nozzle is equal to 10% of the total enthalpy drop. Steam turbine governing and its mechanism ece tutorials. When whole mass of steam is converted into steam then it is called as dry steam. Steam nozzle steam nozzle nozzles for special purposes applications speciallydesigned orifice saves and reduces steam for the same effect.

Flow of gases and steam through nozzles example, the required pressure in the combustion chamber of the space shuttle ssme engine was 20. Friction exists between the steam and the sides of the nozzle. For 16 kgs of steam mass flow rate determine heat drop in nozzle and final state of steam leaving nozzle assuming heat loss to surroundings as 10 kjkg. Numerical solution of steam flow in a nozzle using different. Critical flow nozzles are also called sonic chokes. Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler. The water and steam run through a continuous cycl e of water boiled into steam, used in the engine, condensed back to water, and then pumped back into the boiler for reuse, a cycle first studied scientifically by the. The difference between cornish boiler and lancashire boiler is that a former is fire tube type and latter is water tube type boiler. The effects of different nozzle structures on the performance of a steam ejector have been investigated numerically with the computational fluid dynamics cfd technique. The steam possessesa very high velocity at the end of the expansion, and the enthalpy decreases as.

The variation of steam pressure in the nozzle depends upon the velocity, specific volume and dryness fraction of steam. An efficient nozzle is designed to have higher velocity, greater mass flow and minimum inlet losses. The high pressure steam from the boiler expands while flowing through the convergent divergent nozzle. In a spindleoperated ejector, the nozzle and tapered spindle work together similar to a needle valve. Why is a nozzle used only impulse turbines, and not in. The transition characteristics of the jets also depend on the nozzle cross sectional shape. Steam nozzles ppt steam nozzles a nozzle is a duct of.

Lec10 steam power cycle, steam nozzle lecture series on applied thermodynamics for marine systems by prof. Ideal for saturated steam, superheated steam, and water sampling. Find the properties of the steam at the stagnation state. During the first part of the nozzle, the steam increases its velocity. Halama and hric 3 studied numerical solution of two phase steam flow in the. Other applications include oil in water, water in oil, propant in oil, and sand in oil. In the step of admission of steam turbines reation there are several nozzles that distribute the steam to the blades. Applied thermodynamics videos, lectures, classes, courses, books, tutorials nptel thermodynamics videos, thermodynamics video lectures, thermodynamics video classes. A single moving plate is, therefore, not a practical case. The flow of steam through nozzles may be takenas adiabatic expansion.

Pdf preliminary design of an axial turbine stage for a. The performance of the steam ejectors with five different nozzle structures, namely, conical, elliptical, square, rectangular and crossshaped nozzles, have been compared. The critical pressure ratio for initially dry saturated steam is a. Operating a steam jet vacuum system at steam pressures lower than those specified in the system design will reduce system stability. Power cycles otto cycle spark ignition diesel cycle brayton cycle gas turbine rankinecycle. When the speed of the engine is controlled by means of a valve in a steam pipe, which regulates the pressure of steam entering the engine, then the governing is known as a throttle governing b cutoff governing c bypass governing d none of these. In todays article, you are gonna get a brief knowledge on boiler accessories and mountings. Fixed restriction variable head type flow meters using different sensors like orifice plate, venturi tube, flow nozzle, pitot tube, dall tube, quantity meters like positive displacement meters, mass flow meters etc. A boiler is a closed vessel in which water is heated, vaporized and converted into steam at a pressure higher than the atmospheric pressure. Oxidizer and fuel pumps are powered by combustion turbines that use fuel and engine oxidant as fuel or have other fuel 16, s. Flow is attained at maximum value corresponding to critical exit pressure c. Vanita thakkar bit 17 nozzles a nozzle is a device, a duct of smoothly varying cs area, that increases the velocity of a fluid at the expense of pressure. Reaction turbine 2 iii steam turbine operating range 2 3. Boilers bureau of energy efficiency 27 syllabus boilers.

If the load demand has reduced to 60 % then out of 10 nozzles, 4 nozzles can be closed to provide 60% load with out delay. The smallest section of the nozzle is called throat. This is the heart of an ejector since it converts the energy of pressure to velocity and directs the flow of motive steam into the diffuser. Types, combustion in boilers, performances evaluation, analysis of losses, feed water treatment, blow down, energy conservation opportunities. Power plant lecture notes chapter2 steam power plant cycles. Due to number of openings for either inlet or outlet, stress concentration is more on the structure. Steam nozzles and turbines mechanical engineering questions. Steam nozzles nozzle statistical mechanics free 30day. Boiler mountings and accessories details with video lecture. The steam jet pump is basically comprised of an expanding motive steam nozzle producing high supersonic velocities, a combining chamber for bringing the suction fluid into contiguous or mating contact with the highvelocity motive steam, and a diffuser for compressing both the suction and motive fluids up to the. The steam has a very high velocity at the end of the expansion, and the enthalpy decreases as expansion takes place. How to calculate the steam flow through each nozzle. Steam boilers, engines, nozzles and turbines interview questions and answers pdf. Bellshape nozzles or parabolic nozzles, which are as efficiency as the simplest conical nozzle, but shorter and lighter, though more expensive to manufacture.

Pdf power plant lecture notes chapter4 steam turbine. The focus here will be on boilers sized in between these two extremes, which is also where there is the greatest diversity of design. Thermodynamic and nonthermodynamic properties, microstates and thermodynamic states, concept of energy, microstate driving forces, thermodynamic driving forces, intensive and extensive propertie, the laws of thermodynamics, heat and thermal energy, entropy, energy transport by. The nozzles are of converging or diverging or convergingdiverging type as per the design. They usually save as much as 10% to 20% in motive steam, compared with single nozzle units designed for the same conditions. And then the later part of the nozzle, in which the steam derives more in volume than in velocity. Nozzle exhaust port intake port connecting deflector transfor port piston exhaust gases exhaust. Construction of steam nozzle if great pressure differences exist in front and at the back of inlet nozzles of steam turbines a secure attachment of the nozzles is sometimes rather difficult. Property relationships for pure substances and mixtures, thermodynamic relations, ideal gas mixtures, combustion thermodynamics, gas power cycles, vapour power cycles, refrigeration cycles, reciprocating compressors, compressible flows and steam nozzles.

The particular nozzles tested, of convergentdivergent form, had a straightsided divergent portion of. Steam table lecture 7 ideal gas laws, different processes lecture 8 introduction to vapour power cycle lecture 9 vapour power cycle lecture 10 steam power cycle, steam nozzle lecture 11 basic concept of turbine, velocity diagram lecture 12 steam turbineimpulse. The flow of steam through nozzles may be regarded as adiabatic expansion. The maximum gas flow through a nozzle is determined by critical pressure. The steam which contains some water particles in superposition. Features removal of moisture and oil from steel surfaces. The steamhas a very high velocity at the end of the expansion, and the enthalpy decreases as expansion takes place. Steam boilers, engines, nozzles and turbines, mechanical engineering multiple choice questions objective type questions, mcqs, with question and answers, download free pdf, mechanical engineering, multiple choice questions, objective type questions, mechanical engineering short notes, rapid fire notes, best theory. Isokinetic sampling nozzles probes for sampling gases and liquids including steam and water in steam plants. Steam generator, turbine, pump, nozzle, throttling, the mathematical expression of the 1st law for a closed system, examples of. Pdf power plant lecture notes chapter2 steam power. Numerical study on condensation process of steam flow in. We assume that steam follows an isentropic law pvk k isentropic index for steam for dry saturated steam k 1. Nptel video course ocean engineering advanced marine structures.

Exhaust steam conditions, extraction and admission 7 6. The available energy of steam is first changed into kinetic energy, and this kinetic energy is then transformed into mechanical work. The steam attains very high velocities in the range of ms to 50 ms. Mar 07, 2015 vanita thakkar bit 16 energy conversion in steam turbine energy conversion in steam turbine takes place in two steps. Numerical investigation on the mixing process in a steam. High pressure, high temperature steam expands in nozzles and comes out at a high velocity. The steam passes through the stationary nozzles and is directed at high velocity againstthe rotor buckets causing the rotor to rotate at high speed. Frequently more compact designs and savings in cost can result from such designs. In the impulse steam turbine, the overall transformation of heat into mechanical work is accomplished in two distinct steps. When the dry steam is further heated at constant pressure, the temperature increases the above saturation temperature. The chief use of nozzle is to produce a jet of steam or gas of high velocity to produce thrust for the propulsion of rocket motors and jet engines and to drive steam or gas turbines. The stress concentration will also vary due to the size of hole, location of hole and shape of hole. The course contains the analysis of vapour power cycle i. High velocity steam jets from nozzles impinge on the blades mounted on a wheel rotor get deflected by an angle and suffer a.

The former is a function of x 1 while the later x0. Basic principles of classical and statistical thermodynamics pdf 35p this note covers the following topics. Mix play all mix steam and gas power systems youtube lec 47. Dry saturated steam is expanded in a nozzle from 1. How to determine the steam flow in the nozzles of the stage.

Mechanical power engineering department faculty of engineering. For the love of physics walter lewin may 16, 2011 duration. The inlet narrows to form a throat, which is followed by an enlarging form so that atmospheric pressure is reached by adiabatic expansion, producing a flat jet pattern. Vortex tube refrigeration it consists of nozzle, diaphragm, valve, hotair side, coldair side. Steam nozzles are great for removing moisture as well as oil from steel surfaces. 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. Material brass kbs type spray angle model number inlet connection minimum orifice diameter mm model flow rate of saturated. The far field mean centreline velocity function of a round jet and plane jet are different.

Impulse and reaction stage, degree of reaction, velocity triangle. Vtunptelnmeict project progress report the project on. In order of increasing capacity, three boiler types are the firetube, watertube and waterwall boilers. This course provides a simple understanding of the steam and gas power systems. The expansion causes a very low pressure and increases steam velocity. For hp main steam pipes, a flow nozzle is not strictly needed you can use a short radius elbow with an elbow tap as indicative of steam flow rate, after it is calibrated. It is not possible to increase the flow by increasing inlet pressure.