Power cycles otto cycle spark ignition diesel cycle brayton cycle gas turbine rankinecycle. High pressure, high temperature steam expands in nozzles and comes out at a high velocity. Supersonic flow in cdnozzles presents a rich behaviour, with shock waves and expansion waves usually taking place inside andor outside. Water is heated, turns into steam in boiler and spins a steam turbine which either drives an electrical generator or does some other work, like ship propulsion. In todays article, you are gonna get a brief knowledge on boiler accessories and mountings.
Mechanical engineering steam nozzles and turbines online. Friction exists between the steam and the sides of the nozzle. 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. Introduction to piping engineering by gerald may, p. Steam consumption of steam turbine is depending to required output power and efficiency of the turbine. Trial on centrifugal pump and plotting of characteristic curves 7. Steam boilers, engines, nozzle, turbines mechanical mcqs pdf. Herewith we have shared the steam boilers, engines, nozzle, turbines mechanical mcqs pdf mechanical engineering multiple choice questions and answers pdf. The nozzles are of converging or diverging or convergingdiverging type as per the design. A steam turbine converts the energy of highpressure, high temperature steam. Several nozzle geometries have been used in propulsion systems. What are the effects of friction on the flow through a steam nozzle. Lec10 steam power cycle, steam nozzle lecture series on applied thermodynamics for marine systems by prof. Applied thermodynamics videos, lectures, classes, courses, books, tutorials nptel thermodynamics videos, thermodynamics video lectures, thermodynamics video classes.
Feb 12, 2017 lecture series on steam and gas power systems by prof. In a nozzle steam expands from 12 bar and 300c to 6 bar with flow rate of 5 kgs. Home mcq steam boilers steam nozzles and turbines mechanical engineering questions set 27 steam nozzles and turbines mechanical engineering questions set 27 mcq steam boilers edit. Oxidizer and fuel pumps are powered by combustion turbines that use fuel and engine oxidant as fuel or have other fuel 16, s.
Vanita thakkar bit 5 rankine cycle a thermal power plant is a power plant in which the prime mover is steam driven. Steam nozzles are great for removing moisture as well as oil from steel surfaces. Depending upon the load demand some no of nozzles will be put in service and some put in out of service. The purpose of gasturbine power plants is to produce mechanical power from the expansion of hot gas in a turbine. The flow of steam through nozzles may be takenas adiabatic expansion. In this nozzle the cross sectional area gradually decreases from the entrance area to the minimum area which is the exit. In this case, the spindle is essentially changing the dimensions of the. Lecture series on applied thermodynamics for marine systems by prof. Nozzles and diffusers momentum and continuity equations duration. Rotor means which part rotate and stator means which part is fixed. Oct 15, 2016 steam nozzles and types nozzle is a duct by flowing through which the velocity of a fluid increases at the expense of pressure drop.
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. The project on development of remaining three quadrants to nptel phasei under grant in aid nmeict, mhrd, new delhi. The reheating can be single, double, or triple time process. Jan 14, 2017 steam turbine velocity digram duration. Boilers bureau of energy efficiency 27 syllabus boilers.
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. The mechanical engineering online mock test exam is very helpful for all students. In nozzle the expansive property of the steam is utilized to. 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. Pdf power plant lecture notes chapter4 steam turbine. Steam nozzles a nozzle is a duct of smoothly varying cross sectional area, in which a steadily flowing fluid can be accelerated to a high velocity by a drop in pressure of the fluid along the duct. Steam nozzle steam nozzle objective type questions and. Nozzles are used in steam and gas turbines, jet engines, rockets, in flow measurement, in injectors for pumping water, in ejectors for removing air from condensers etc. Assuming that the steam expands isentropically according to a law pv1. 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.
Assume friction loss in the nozzle is equal to 10% of the total enthalpy drop. 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. What are the various types of nozzles and their functions. Efficiency will depend on turbine size or rotor diameter, blade geometries, speed, extreme condition of steam and other losses. High velocity steam jets from nozzles impinge on the blades mounted on a wheel rotor get deflected by an angle and suffer a. Supersaturated flow or metastable flow of in nozzles. The steam attains very high velocities in the range of ms to 50 ms. Trial on centrifugal air compressor and plotting its characteristics learning resources. This course provides a simple understanding of the steam and gas power systems. The difficulties are eliminated by milling or otherwise machining the nozzles into a complete or undivided solid ring. This is done to eliminate erosion and corrosion problems in the bladings and to enhance the power output and efficiency. The temperature to which steam can be superheated is limited by metallurgical consideration. If steam at high pressure is allowed to expand through a stationary nozzle, the result will be a drop in.
Syllabus, question banks, books, lecture notes, important part a 2 marks questions and important part b 16 mark questions, previous years question papers collections. In a spindleoperated ejector, the nozzle and tapered spindle work together similar to a needle valve. Due to the high velocities, the time up to which the steam resides in the nozzle is small, and there may not be sufficient. The high pressure steam from the boiler expands while flowing through the convergent divergent nozzle. Applied thermodynamics videos, lectures, classes, courses, books, tutorials nptel thermodynamics videos, thermodynamics video lectures.
The simplest plant is the open turbine gas cycle used to produce electrical. Find the properties of the steam at the stagnation state. This is known as critical pressure ratio and different for different fluids. Dec 16, 2019 the upper pipe has a steam valve and the lower pipe has a water valve which is bolted to the boiler plated by two flanges. The steam should be dry and saturated, unless the system specifi. Me6404 thermal engineering te syllabus unit i gas power cycles. After it passes through the turbine, the steam is condensed in a.
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. The classical quasionedimensional laval nozzle, which has a slender geometry, with a rapidly. An efficient nozzle is designed to have higher velocity, greater mass flow and minimum inlet losses. Boiler mountings and accessories details with video lecture. The main use of steam nozzle in steam turbines is to produce a jet of steam with a high velocity. Steam nozzles and turbines mechanical engineering questions. The course contains the analysis of vapour power cycle i. The focus here will be on boilers sized in between these two extremes, which is also where there is the greatest diversity of design. The mixed pressure turbine is established in industrial plants e.
The available energy of steam is first changed into kinetic energy, and this kinetic energy is then transformed into mechanical work. Vortex tube refrigeration it consists of nozzle, diaphragm, valve, hotair side, coldair side. The flow of steam through nozzles may be regarded as adiabatic expansion. The high velocity steam coming out of the nozzles impinges on the blades. In these notes we will focus on stationary plants for electric power generation, however, gas turbines are also used as jet engines in aircraft propulsion. Flow of gases and steam through nozzles example, the required pressure in the combustion chamber of the space shuttle ssme engine was 20.
A source of dry steam at or slightly above design pressures must be available at the ejector nozzles at all times. Nozzle is a duct of varying crosssectional area in which the velocity increases with the corresponding drop in pressure. Otto, diesel, dual, brayton cycles, calculation of mean effective pressure, and air standard efficiency comparison of cycles. Steam nozzles nozzle statistical mechanics free 30. Mechanical engineering steam nozzles and turbines online test. It converts a part of the energy of high temperature and high pressure. In turbines there are basically 2 part one is called rotor and another is known as stator. As steam expands in the nozzle, the pressure and temperature in it drop, and it is likely that the steam start condensing when it strikes the saturation line. The expansion causes a very low pressure and increases steam velocity. Mar 14, 2019 here we are providing mechanical engineering steam nozzles and turbines online test series in english. In this method the steam flow is regulated by opening or closing some set of nozzles of the turbine. Superheating the steam to higher temperatures has very desirable effect. Steam turbine governing and its mechanism ece tutorials. Steam at 20 bar and 300 oc enters a convergentdivergent nozzle at the rate of 0.
Ramamurthi, department of mechanical engineering, iit madras. The steamhas a very high velocity at the end of the expansion, and the enthalpy decreases as expansion takes place. Nozzle is the stator part of turbine means it is fixed part. Steam turbine 1 content chapter description page i purpose 2 ii steam turbine types 2 2. Reaction turbine 2 iii steam turbine operating range 2 3. These nozzles are actuated by independent control mechanisms. Steam nozzles nozzle statistical mechanics free 30day. Steam power engineering introduction video youtube.
They usually save as much as 10% to 20% in motive steam, compared with singlenozzle units designed for the same conditions. Operating a steamjet vacuum system at steam pressures lower than those specified in the system design will reduce system stability. Dec 01, 2015 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. The critical pressure ratio for initially dry saturated steam is a. First increase dryness fraction upto certain limit and then decrees it. 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. Check mechanical engineering mock test series 2020. Bellshape nozzles or parabolic nozzles, which are as efficiency as the simplest conical nozzle, but shorter and lighter, though more expensive to manufacture. In order of increasing capacity, three boiler types are the firetube, watertube and waterwall boilers. 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. Sep 14, 2018 herewith we have shared the steam boilers, engines, nozzle, turbines mechanical mcqs pdf mechanical engineering multiple choice questions and answers pdf. It steam power plant decreases the moisture content of the steam at the turbine exit as can be seen in ts diagram as shown in figure 2. 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.
Dual pressure system is also utilized in combined cycle. Here we are providing mechanical engineering steam nozzles and turbines online test series in english. Steam nozzles ppt steam nozzles a nozzle is a duct of. It is very useful for all kind of gate, ssc, ese and other competitive examinations. Mar 07, 2015 vanita thakkar bit 16 energy conversion in steam turbine energy conversion in steam turbine takes place in two steps. Dry saturated steam is expanded in a nozzle from 1.
The smallest section of the nozzle is called throat. The nozzles are designed for lowest operating pressure ratio between nozzle throat and exit. Vtunptelnmeict project progress report the project on. Steam turbine is a type of turbomachine which is an assembly of nozzles and blades. A boiler is a closed vessel in which water is heated, vaporized and converted into steam at a pressure higher than the atmospheric pressure. Lecture series on steam and gas power systems by prof. Types, combustion in boilers, performances evaluation, analysis of losses, feed water treatment, blow down, energy conservation opportunities. The heat energy required for steam generation is produced by burning. The upper pipe is opened to the steam and the lower pipe is open to the water with the help of steam and water valves, respectively. Steam nozzle steam nozzle objective type questions and answers. The available energy of steam is first changed into kinetic energy, and this kinetic energy is. The variation of steam pressure in the nozzle depends upon the velocity, specific volume and dryness fraction of steam. This feature enables the use of nozzle governing for part load operation. Pdf me6404 thermal engineering te books, lecture notes.
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