Technology & Engineering
Gas Turbine
A gas turbine is a type of internal combustion engine that converts natural gas or liquid fuel into mechanical energy. It operates on the principle of continuous combustion, where air is compressed and mixed with fuel to generate high-speed, high-temperature gas flow. This flow then drives a turbine to produce power for various applications, such as electricity generation and aircraft propulsion.
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12 Key excerpts on "Gas Turbine"
No longer available |Learn more- (Author)
- 2014(Publication Date)
- White Word Publications(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 4 Gas Turbine A typical axial-flow Gas Turbine turbojet, the J85, sectioned for display. Flow is left to right, multistage compressor on left, combustion chambers center, two-stage turbine on right A Gas Turbine , also called a combustion turbine , is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between. Gas Turbine may also refer to just the turbine component. ________________________ WORLD TECHNOLOGIES ________________________ Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high pressure environment of the combustor, combustion of the fuel increases the temperature. The products of the combustion are forced into the turbine section. There, the high velocity and volume of the gas flow is directed through a nozzle over the turbine's blades, spinning the turbine which powers the compressor and, for some turbines, drives their mechanical output. The energy given up to the turbine comes from the reduction in the temperature and pressure of the exhaust gas. Energy can be extracted in the form of shaft power, compressed air or thrust or any combination of these and used to power aircraft, trains, ships, generators, or even tanks. History • 150: Hero's Engine ( aeolipile ) — Apparently, Hero's steam engine was taken to be no more than a toy, and thus its full potential not realized for centuries. • 1500: The Chimney Jack was drawn by Leonardo da Vinci: Hot air from a fire rises through a single-stage axial turbine rotor mounted in the exhaust duct of the fireplace and turning the roasting spit by gear/ chain connection. • 1551: Taqi al-Din invented a rudimentary form of an impulse steam turbine, which he used to power a self-rotating spit.
eBook - ePub- Paul Breeze(Author)
- 2014(Publication Date)
- Newnes(Publisher)
To cater for the growing power generation market, the main manufacturers—and there are only a limited number of these because the Gas Turbine is a very specialized high-technology machine—quickly began to build bigger and more efficient engines. Today, single engines of up to 400 MW in capacity are available. Most of these are aimed at the combined cycle market and have efficiencies on their own between 38% and 42%. However, when used in a modern integrated combined cycle plant the latter should be capable of around 60% efficiency.Gas Turbine principle
A Gas Turbine is a machine that harnesses the energy contained within a gas—either the kinetic energy of motion of a flowing gas stream or the potential energy of a gas under pressure—to generate rotary motion. In the case of a Gas Turbine this gas is usually, though not necessarily, air. The earliest human-made device of this type for harnessing the energy in moving air was a windmill described by Hero of Alexandria in the 1st century AD.This earliest known windmill was a near relative of today’s wind turbine, which though clearly a type of Gas Turbine, is far removed from the modern Gas Turbine concept. Closer in concept to the Gas Turbine was the smokejack, developed in the middle of the 2nd century AD. As described in the 17th century by John Wilkins, Bishop of Chester, the smokejack used hot air rising through a chimney to move windmill vanes within that chimney and drive a shaft that could be used to rotate a spit for roasting meat.This principle of harnessing moving air within an enclosed chamber to create rotary motion for driving machinery was developed further during the industrial revolution. Following this principle, the 19th century saw a number of predecessors to the Gas Turbine. These used some form of compressor to generate a human-made flow of pressurized air that was fed into an enclosed turbine. In these machines the compressor was usually separate from the turbine.The direct ancestor of the modern Gas Turbine was first outlined in a patent granted to German engineer F. Stolze in 1872. In Stolze’s design, as in that of all modern Gas Turbines, an axial compressor was used to generate a flow of pressurized air. This air was then mixed with fuel and ignited, creating a very energetic flow of hot, high-pressure gas that was fed into a turbine. Crucially, the compressor and the turbine were mounted on the same shaft (Figure 4.1
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
____________________ WORLD TECHNOLOGIES ____________________ Chapter 4 Gas Turbine A typical axial-flow Gas Turbine turbojet, the J85, sectioned for display. Flow is left to right, multistage compressor on left, combustion chambers center, two-stage turbine on right A Gas Turbine , also called a combustion turbine , is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between. Gas Turbine may also refer to just the turbine component. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high pressure environment of the combustor, combustion of the fuel ____________________ WORLD TECHNOLOGIES ____________________ increases the temperature. The products of the combustion are forced into the turbine section. There, the high velocity and volume of the gas flow is directed through a nozzle over the turbine's blades, spinning the turbine which powers the compressor and, for some turbines, drives their mechanical output. The energy given up to the turbine comes from the reduction in the temperature and pressure of the exhaust gas. Energy can be extracted in the form of shaft power, compressed air or thrust or any combination of these and used to power aircraft, trains, ships, generators, or even tanks. History • 150: Hero's Engine ( aeolipile ) — Apparently, Hero's steam engine was taken to be no more than a toy, and thus its full potential not realized for centuries. • 1500: The Chimney Jack was drawn by Leonardo da Vinci: Hot air from a fire rises through a single-stage axial turbine rotor mounted in the exhaust duct of the fireplace and turning the roasting spit by gear/ chain connection. • 1551: Taqi al-Din invented a rudimentary form of an impulse steam turbine, which he used to power a self-rotating spit.
eBook - PDFFundamentals of Heat Engines
Reciprocating and Gas Turbine Internal Combustion Engines
- Jamil Ghojel(Author)
- 2020(Publication Date)
- Wiley-ASME Press Series(Publisher)
251 Part III Gas Turbine Internal Combustion Engines 252 Introduction III: History and Classification of Gas Turbines Gas Turbines are air-breathing, internal combustion heat engines. There are two types of Gas Turbine cycles: closed and open. Only open cycle Gas Turbine engine will be considered in this book, and the configurations that will be discussed are highlighted in Chart III.1. The development of the steam turbine late in the nineteenth century, beginning with the introduction of the first practical engine by Charles Parsons in 1884, was a logical evolu-tion from piston steam engines to rotating heat engines. Similarly, the development of the Gas Turbine internal combustion engine, starting with the experimental engines of Rene Armengaud and Charles Lemale as early as 1903, was another evolutionary step to replace the steam turbine by eliminating the bulky boiler, condenser, and circulating water. It was also envisaged that with its superior rotary power generation, the Gas Turbine would replace the piston engine and its cumbersome reciprocating piston-crank mechanism. The gas tur-bine has been successful in this endeavour only partially. The steam turbine still reigns supreme in electric power generation ( ∼ 80% of all electric power in the United States), and the piston engine is still dominant in land transport, industrial, and agricultural machinery and remains a serious competitor in low-range power generation. However, the Gas Turbine has been very successful in other areas such as base, midrange, and peak load electric power generation, aircraft propulsion (subsonic and supersonic), ship propulsion, and pump and compressor drives for liquid and gas pipelines. It is also an ideal heat engine for use in com-bined cycle and cogeneration applications, operating with impressive thermal efficiencies.
eBook - PDFSustainable Utility Systems
Modelling and Optimisation
- Petar Sabev Varbanov, Jiří Škorpík, Jiří Pospíšil, Jiří Jaromír Klemeš(Authors)
- 2020(Publication Date)
- De Gruyter(Publisher)
7 Gas Turbines The working fluid of Gas Turbines is heated gas or airflow mixed with products of com-bustion. The Gas Turbines are most often used with combustion chambers, which are based on the so-called open cycle (Razak, 2007). Therefore, they are also often referred to as combustion turbines. An open-cycle Gas Turbine typically contains a turbocom-pressor section, a combustion chamber and a turbine section. For most Gas Turbines, simple designs are developed, since the technology has been tightly related to the jet engines for propulsion. In fact, many Gas Turbine designs for industrial use are derived from jet engines, which have given rise to the classification “ aeroderivative ” gas tur-bines. Figure 7.1 shows a cross-sectional visualisation of an industrial Gas Turbine. The supplied fuel – usually gaseous or liquid – is burned inside the combustion chamber, within the airflow, supplied by the compressor. The combustion releases reaction products, which – together with the combustion air – form the flue gas. The flue gas from the combustion chamber enters the expander (turbine) section. Part of the power output of the turbine section is used by the compressor section and the remainder is supplied to an electric generator (generation configuration) or another device (direct-drive configuration). Gas Turbines are generally installed in various types of applications (Soares, 2020): – standalone configurations for power generation; – for direct drive, for example, for natural gas liquefaction; – Combined Heat and Power (CHP) generation plants; – for driving ships, and as jet engines for propulsion of airplanes. ˙ m co a d e ˙ m fuel ˙ m s c b ˙ m a 0 Fig. 7.1: A principle diagram of a Gas Turbine (combustion turbine) for industrial use ( Š korpík, 2020b).
eBook - PDFGas Turbines
Internal Flow Systems Modeling
- Bijay Sultanian(Author)
- 2018(Publication Date)
- Cambridge University Press(Publisher)
1 Overview of Gas Turbines for Propulsion and Power Generation 1.0 Introduction This is the age of Gas Turbines with their ever-growing contributions to people’s living standard and well-being. As a great technological marvel, perhaps next only to the inventions of electricity and light bulb, Gas Turbines have become indispensible in commercial aviation, shrinking the travel time around the globe in hours rather than days and weeks as was the case in the early 1990s by sea. Almost all modern military fighter jets with high maneuverability deploy Gas Turbine engines. Even in liquid rocket propulsion, Gas Turbines are used to pump liquid fuel and oxidizer to the combustion chamber at high pressure. Nonflying Gas Turbines, where weight considerations are important only to reduce material cost, have revolutionized the means of power generation both on land and sea. Their impressive applications portfolio includes utility and industrial power generation, combined heat and power (CHP), oil and gas, and mechanical drive. Gas Turbines are a strong candidate of choice where fast power is needed in the distributed power generation for commercial buildings and facilities. Their fuel flexibility is leveraged in applications involving biogas, biomass, waste gas, and waste to energy to produce utility steam. In view of the growing demand for energy around the world, it is highly unlikely that wind turbines and other forms of turbomachinery using renewable will make Gas Turbines obsolete as they (Gas Turbines) did to piston-powered reciprocating machines in the early part of the last century. In fact, in the foreseeable future, the world demand for Gas Turbines for both propulsion and power generation is expected to grow monotonically. Bathie (1996), Soares (2014), and Saravanamuttoo et al. (2017) present the history of Gas Turbines for aircraft propulsion and for various power-generation applications.
eBook - PDF- Eugene L. Keating(Author)
- 2007(Publication Date)
- CRC Press(Publisher)
It was not until the 1960s, however, that jet engines entered into satisfactory commercial use. After the 1970s, aircraft-derivative Gas Turbines began to find a variety of new applications, including marinized aircraft designs for ship propulsion, hovercraft applications, and industrialized designs for stationary power generation. Many factors helped to slow development of a reliable Gas Turbine, including the low compressor and turbine component efficiencies of early designs, lack of suitable materials able to withstand locally high temperatures developed in hot sections resulting from continuous combustion, and unacceptably large total stagnation pressure loss across the combustor. Worldwide Gas Turbine industries today manufacture civilian as well as Gas Turbine Engine Combustion 483 military power plants for air, land, and sea applications. Engineering publications and standards are available that support all professional aspects relevant to the science and technology of Gas Turbine components, including compressors, combustors, turbines, intercoolers, reheaters, and/or regenerators. Reference material also deals with various power and thrust configurations of Gas Turbine engines, such as turboshaft, turboprop, turbofan, electric power generators, and turbochargers. Efforts are now underway to try to develop new microturbine machinery for unique applications. Chapter 12 will cover only essential and important fuel-engine energetic charac-teristics of Gas Turbine engines; see Figure 12.2. Material discussion, therefore, will focus primarily on the major combustion component, the combustor. This chapter will be limited to the following issues: the thermochemical nature of the reactive mixture, general Gas Turbine fuel characteristics, basic combustion processes, and related emissions problems generally associated with Gas Turbine operation, as well as basic combustor design.
eBook - PDFHandbook of Electrical Engineering
For Practitioners in the Oil, Gas and Petrochemical Industry
- Alan L. Sheldrake(Author)
- 2016(Publication Date)
- Wiley(Publisher)
2.1.5 Fuel for Gas Turbines The fuels usually consumed in Gas Turbines are either in liquid or dry gas forms and, in most cases, are hydrocarbons. In special cases non-hydrocarbon fuels may be used, but the machines may then need to be specially modified to handle the combustion temperatures and the chemical composition of the fuel and its combustion products. Gas Turbine internal components such as blades, vanes, combustors, seals and fuel gas valves are sensitive to corrosive components present in the fuel or its combustion products such as carbon dioxide, sulphur, sodium or alkali contaminants, see also sub-section 2.2.5. The fuel can generally be divided into several classifications:- • Low heating value gas. • Natural gas. • High heating value gas. • Distillate oils. • Crude oil. • Residual oil. 2.2 ENERGY OBTAINED FROM A Gas Turbine A Gas Turbine functions as a heat engine using the thermodynamic Joule cycle, as explained in many textbooks, see for example References 1 to 5. Most Gas Turbines used in the oil industry use the 24 HANDBOOK OF ELECTRICAL ENGINEERING Figure 2.5 Gas Turbine thermodynamic cycle. Simple-cycle Gas Turbine. ‘simple-cycle’ version of the Joule cycle. The main components of the Gas Turbine are shown in Figure 2.5. The thermodynamic relationships used to describe the operation of the Gas Turbine are the pressure (P ) versus volume (V ) characteristic in Figure 2.6 and the temperature (T ) versus entropy (S ) characteristic in Figure 2.7. These figures also show the effect of practical inefficiencies that occur both in the air compressor and the turbine. Air is drawn into the compressor at atmospheric pressure P 1 (in practice slightly lower due to the inlet silencer, filter and ducting) and atmospheric temperature T 1 , and compressed adiabatically to a higher pressure P 2 to reduce its volume to V 2 and raise its temperature to T 2 . The adiabatic compression is given by the following equations; see standard textbooks e.g.
- Tomasz Krysinski, François Malburet(Authors)
- 2020(Publication Date)
- Wiley-ISTE(Publisher)
The objective of this chapter is to present different transportation powertrains through their basic principles of operation and improvements used to reduce their consumption and pollutant emissions. Gas Turbines, internal combustion engines and electric engines are presented in this chapter.It is important to mention in this introduction that the needs of propulsion systems are not the same according to two industrial sectors considered in this chapter: the aeronautics sector and the automotive sector. Some comparative elements are presented as examples in Table 2.1 .Table 2.1. Comparison of data from aeronautical/automotive specifications [AOU 15 ]AeronauticsAutomobilePower consumption~ 105 hp~ 102 hpLifespan~ 105 h~ 103 hRevision interval~ 104 h~ 102 hMaintenance costs~ 102 $/h~ 100 $/hCatalog price~ 107 $~ 103 $2.2. Gas Turbines
2.2.1. General operating principles
A Gas Turbine, abbreviated GT, is an internal combustion engine that produces two types of energy in the context of aeronautical applications:– mechanical energy used for driving an aircraft propeller or helicopter rotor via a gearbox; – kinetic energy given to the gases at the turbine outlet and expanded in the nozzle to produce thrust on an aircraft. A turbojet is a typical application of this type of propulsion.A Gas Turbine is shown in Figure 2.1 . Atmospheric air (point 1) is sucked in by a gas compressor (GC). The input parameters are pressure p1 and temperature T1 . The air is then compressed to pressure p2 at temperature T2 (point 2). It then passes through the combustion chamber (CCh), where the liquid or gaseous fuel is supplied. The air mass flow rate is noted as qmc .Theoretically, combustion is carried out at constant pressure, but in practice, because of the drop in pressure, the pressure p3 at the turbine inlet at T3 is slightly lower than p2 (it is approximately 95% to 98% of p2 ).Figure 2.1. Diagram of a single-shaft Gas Turbine. ASTAZOU single-shaft Gas Turbine in Gazelle (source: Airbus). For a color version of this figure, see www.iste.co.uk/krysinski/automotive.zip
No longer available |Learn moreAdvanced Thermodynamics
Fundamentals, Mathematics, Applications
- Mehrzad Tabatabaian, R. K. Rajput(Authors)
- 2017(Publication Date)
- Mercury Learning and Information(Publisher)
C H A P T E R 12 In This Chapter l Overview l Classification of Gas Turbines l Merits of Gas Turbines l Demerits of Gas Turbines l Constant Pressure Combustion Gas Turbines l Constant Volume Combustion Turbines l GasTurbineFuels l Jet Propulsion l Rocket Engines l Exercises Gas TurbineS AND JET PROPULSION 12.1. Overview Probably a windmill was the first turbine to produce useful work, wherein there is no pre-compression and no combustion. The characteristic features of a Gas Turbine as we think of the name today include a compres- sion process and a heat addition (or combustion) process. The Gas Turbine represents perhaps the most satisfactory way of producing very large quan- tities of power in a self-contained and compact unit. The Gas Turbine may have a future use in conjunction with the oil engine. For smaller Gas Turbine units, the inefficiencies in compression and expansion processes become greater, and to improve the thermal efficiency it is necessary to use a heat exchanger. In order that a small Gas Turbine may compete for economy with 614 • ADVANCED THERMODYNAMICS the small oil engine or petrol engine, it is necessary that a compact effec- tive heat exchanger be used in the Gas Turbine cycle. The thermal efficiency of the Gas Turbine alone is still quite modest—20 to 30%—compared with that of a modern steam turbine plant—38 to 40%. It is possible to con- struct combined plants whose efficiencies are of the order of 45% or more. Higher efficiencies might be attained in the future. The following are the major fields of application of Gas Turbines: • Aviation • Power generation • Oil and gas industry • Marine propulsion The efficiency of a Gas Turbine is not the criteria for the choice of this plant. A Gas Turbine is used in aviation and marine fields because it is self- contained, lightweight, does not require cooling water, and generally fits into the overall shape of the structure.
eBook - PDFThe Dynamics of Energy
Supply, Conversion, and Utilization
- Horacio Perez-Blanco(Author)
- 2009(Publication Date)
- CRC Press(Publisher)
Some natural gas is used for transportation in IC engines. Of all these applications, we select power production for further study. Of all possible conver-sions, power generation best uses the unique characteristics of natural gas. G AS T URBINES AND C OGENERATION Gas Turbines are a way of implementing the Brayton cycle. Following Figure 4.2, air is compressed (from 1 to 2), fuel is injected in a combustion chamber (from 2 to 3), and the hot gases are expanded in a turbine to release work (3 to 4). The turbine 128 The Dynamics of Energy: Supply, Conversion, and Utilization releases more work than required for compression, and hence useful work is devoted to electricity generation. The main idea behind the cycle is illustrated in the schematic of Figure 4.3, where we simplify the cycle in such a way that air is the working substance. Hence, the combustion process is replaced with heat addition. The chart shows the temperature versus the entropy of the air. To any value of air temperature and entropy, there cor-responds a point on the chart. When air is compressed adiabatically (from 1 to 2), with entropy increasing due to irreversibilities in the flow, point 2 lies to the right and above point 1 because the compression operation increases the temperature, and the irreversibilities do so, too. The temperature of constant pressure lines can be shown to increase (exponentially) with entropy. At constant pressure, heat addition brings the temperature up to point 3, with T 3 being the highest cycle temperature, called, for short, the turbine inlet tem-perature (TIT). Adiabatic expansion in the turbine cools the fluid, still increasing its entropy, to point 4. The reader may wonder why the compression and expansion are adiabatic. The main reason is that these processes occur so fast that there is no time for substantial heat transfer to occur.
eBook - PDF- Philip P. Walsh, Paul Fletcher(Authors)
- 2008(Publication Date)
- Wiley-Blackwell(Publisher)
1.0 Introduction This chapter provides an insight into why the Gas Turbine engine has been dominant in certain applications, while having only minimal success in others. Though it has undoubtedly had the greatest impact on aircraft propulsion, background information on all potential major appli-cations is provided, including a description of an electrical grid system and how to evaluate marine vessel and automotive vehicle shaft power requirements. An understanding of the application is essential to appreciate fully the wider implications of Gas Turbine performance. The attributes of the Gas Turbine are compared with other competing powerplants in relation to the requirements of each application. This discussion includes the reasons for selecting particular Gas Turbine configurations and cycles. High reliability and availability are pre-requisites. Examples of engines and applications currently in service are provided. Engine configurations discussed herein, such as simple or combined cycle, are described fully immediately before this chapter. Performance terms used are defined in section 6.2. Aspects of Gas Turbine performance which impact the choice of engine for a given application are comprehensively presented in later chapters. These include detailed cycle design, transient performance, starting performance, etc. 1.1 Comparison of Gas Turbine and diesel engines The Gas Turbine competes with the high and medium speed diesel engines in all non-aero shaft power applications up to 10 MW. It is therefore logical to compare the powerplants before discussing applications individually. Low speed diesels are heavier and larger than high/medium speed diesels, the main difference being a higher residence time for fuel vaporisation due to a longer stroke, lower speed and indirect injection. They are used where size is not so important and can burn less refined, lower cost fuel.
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