Gas turbine - Wikipedia. For turbines in electricity, see Wind turbine. Wind Turbine Engineering PdfFor turbines in general, see Turbine. A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in between. The basic operation of the gas turbine is similar to that of the steam power plant except that air is used instead of water. Fresh atmospheric air flows through a compressor that brings it to higher pressure. Energy is then added by spraying fuel into the air and igniting it so the combustion generates a high- temperature flow. This high- temperature high- pressure gas enters a turbine, where it expands down to the exhaust pressure, producing a shaft work output in the process. The turbine shaft work is used to drive the compressor and other devices such as an electric generator that may be coupled to the shaft. The energy that is not used for shaft work comes out in the exhaust gases, so these have either a high temperature or a high velocity. The purpose of the gas turbine determines the design so that the most desirable energy form is maximized. Gas turbines are used to power aircraft, trains, ships, electrical generators, and tanks. When the lamp is lit, the heated airflow rises and drives an impeller with horse- riding figures attached on it, whose shadows are then projected onto the outer screen of the lantern. His invention had most of the elements present in the modern day gas turbines. The Gas Turbine Engineering Handbook has been the standard for engineers involved in the design, selection, and operation of gas turbines. This revision includes new case histories, the latest techniques, and new designs to comply with recently passed legislation. EDF Incorporated has provided full service engineering solutions to the OEM, MRO and government propulsion industry since 1978. We specialize in the design and development of engine test facilities and equipment for: - Indoor and outdoor testing - Gas Turbine. Heavy duty TURBINE ELECTRIC FANS . ELECTRIC FAN ENGINEERING (EFE) is a leader in pioneering, researching and developing numerous patented. Wind Turbine Power Calculations RWE npower renewables Mechanical and Electrical Engineering Power Industry INTRODUCTION RWE npower is a leading integrated UK energy company and is part of the RWE Group, one of Europe's leading utilities. The International Journal of Energy and Environmental Engineering (IJEEE) is a multi-disciplinary, peer-reviewed open access journal published under the brand SpringerOpen, covering all areas of energy and environment related fields that apply to the science and engineering communities. The view from our science window, we can see a landscape of newly erected wind turbines going up. So naturally, I had to incorporate that into our labs! I will admit that engineering is my weak area of STEM, but if I expect my students to be uncomfortable while. Welcome to the Department of Mechanical Engineering and Energy Engineering (MEE) at the University of North Texas (UNT)! The department is committed to educating. The Department of Mechanical and Energy Engineering Department would like to reach out. GAS TURBINE PERFORMANCE—WHAT MAKES THE MAP? 251 When combining the above efficiency with the expression for temperature and the isentropic relationship for temperature and pressure (T 2/T 1 = (P 2/P 1) The turbine was designed to power a horseless carriage. Marc Antoine Francois Mennons for a . The patent shows that it was a gas turbine and the drawings show it applied to a locomotive. Teleshov), a Russian aviation pioneer. This principle of propulsion is still of some use. Three 4- ton 1. 00 k. W Parsons radial flow generators were installed in Cambridge Power Station, and used to power the first electric street lighting scheme in the city. Charles Gordon Curtis patented the first gas turbine engine in the USA (. In 1. 90. 3, Moss became an engineer for General Electric's Steam Turbine Department in Lynn, Massachusetts. His design used a small turbine wheel, driven by exhaust gases, to turn a supercharger. Using rotary compressors and turbines it produced 1. Griffith resulting in the publishing in 1. An Aerodynamic Theory of Turbine Design. Working testbed designs of axial turbines suitable for driving a propellor were developed by the Royal Aeronautical Establishment proving the efficiency of aerodynamic shaping of the blades in 1. The first successful use of his engine was in April 1. Following the gas turbine principle, the steam evaporation tubes are arranged within the gas turbine combustion chamber; the first Velox plant was erected in Mondeville, France. In Beznau, Switzerland the first commercial reheated/recuperated unit generating 2. MW was commissioned. Together, these make up the Brayton cycle. In a real gas turbine, mechanical energy is changed irreversibly (due to internal friction and turbulence) into pressure and thermal energy when the gas is compressed (in either a centrifugal or axial compressor). Heat is added in the combustion chamber and the specific volume of the gas increases, accompanied by a slight loss in pressure. During expansion through the stator and rotor passages in the turbine, irreversible energy transformation once again occurs. If the engine has a power turbine added to drive an industrial generator or a helicopter rotor, the exit pressure will be as close to the entry pressure as possible with only enough energy left to overcome the pressure losses in the exhaust ducting and expel the exhaust. For a turboprop engine there will be a particular balance between propeller power and jet thrust which gives the most economical operation. In a jet engine only enough pressure and energy is extracted from the flow to drive the compressor and other components. The remaining high pressure gases are accelerated to provide a jet to propel an aircraft. The smaller the engine, the higher the rotation rate of the shaft(s) must be to attain the required blade tip speed. Blade- tip speed determines the maximum pressure ratios that can be obtained by the turbine and the compressor. This, in turn, limits the maximum power and efficiency that can be obtained by the engine. In order for tip speed to remain constant, if the diameter of a rotor is reduced by half, the rotational speed must double. For example, large jet engines operate around 1. Simple turbines might have one main moving part, the compressor/shaft/turbine rotor assembly (see image above), with other moving parts in the fuel system. However, the precision manufacture required for components and the temperature resistant alloys necessary for high efficiency often make the construction of a simple gas turbine more complicated than a piston engine. More advanced gas turbines (such as those found in modern jet engines) may have 2 or 3 shafts (spools), hundreds of compressor and turbine blades, movable stator blades, and extensive external tubing for fuel, oil and air systems. Thrust bearings and journal bearings are a critical part of design. Traditionally, they have been hydrodynamic oil bearings, or oil- cooled ball bearings. These bearings are being surpassed by foil bearings, which have been successfully used in micro turbines and auxiliary power units. Because of the stresses of operation, turbine materials become damaged through these mechanisms. As temperatures are increased in an effort to improve turbine efficiency, creep becomes more significant. To limit creep, thermal coatings and superalloys with solid- solution strengthening and grain boundary strengthening are used in blade designs. Protective coatings are used to reduce the thermal damage and to limit oxidation. These coatings are often stabilized zirconium dioxide- based ceramics. Using a thermal protective coating limits the temperature exposure of the nickel superalloy. This reduces the creep mechanisms experienced in the blade. Oxidation coatings limit efficiency losses caused by a buildup on the outside of the blades, which is especially important in the high- temperature environment. The microstructure of these alloys is composed of different regions of composition. A uniform dispersion of the gamma- prime phase . The addition of these elements reduces the diffusion of the gamma prime phase, thus preserving the fatigue resistance, strength, and creep resistance. Flow is left to right, multistage compressor on left, combustion chambers center, two- stage turbine on right. Airbreathing jet engines are gas turbines optimized to produce thrust from the exhaust gases, or from ducted fans connected to the gas turbines. Jet engines that produce thrust from the direct impulse of exhaust gases are often called turbojets, whereas those that generate thrust with the addition of a ducted fan are often called turbofans or (rarely) fan- jets. Gas turbines are also used in many liquid propellant rockets, the gas turbines are used to power a turbopump to permit the use of lightweight, low pressure tanks, which reduce the empty weight of the rocket. Turboprop engines. Turboprop engines are used on small aircraft such as the general- aviation Cessna 2. Caravan and Embraer EMB 3. Tucano military trainer, medium- sized commuter aircraft such as the Bombardier Dash 8 and large aircraft such as the Airbus A4. M transport and the 6. Tupolev Tu- 9. 5 strategic bomber. Aeroderivative gas turbines. They are also used in the marine industry to reduce weight. The General Electric LM2. General Electric LM6. Rolls- Royce RB2. Rolls- Royce Avon are common models of this type of machine. A combustion chamber is fabricated and plumbed between the compressor and turbine sections. Most turbojet- powered model aircraft are now using these commercial and semi- commercial microturbines, rather than a Schreckling- like home- build. They supply: compressed air for air conditioning and ventilation,compressed air start- up power for larger jet engines,mechanical (shaft) power to a gearbox to drive shafted accessories or to start large jet engines, andelectrical, hydraulic and other power- transmission sources to consuming devices remote from the APU. Industrial gas turbines for power generation. They are also much more closely integrated with the devices they power. When the gas turbine is used solely for shaft power, its thermal efficiency is about 3. However, it may be cheaper to buy electricity than to generate it. Therefore, many engines are used in CHP (Combined Heat and Power) configurations that can be small enough to be integrated into portable container configurations. Gas turbines can be particularly efficient when waste heat from the turbine is recovered by a heat recovery steam generator to power a conventional steam turbine in a combined cycle configuration. They can also be run in a cogeneration configuration: the exhaust is used for space or water heating, or drives an absorption chiller for cooling the inlet air and increase the power output, technology known as Turbine Inlet Air Cooling. Another significant advantage is their ability to be turned on and off within minutes, supplying power during peak, or unscheduled, demand. Since single cycle (gas turbine only) power plants are less efficient than combined cycle plants, they are usually used as peaking power plants, which operate anywhere from several hours per day to a few dozen hours per year. In areas with a shortage of base- load and load following power plant capacity or with low fuel costs, a gas turbine powerplant may regularly operate most hours of the day. A large single- cycle gas turbine typically produces 1. The power range varies from 1 megawatt up to 5. The majority of installations are used within the oil and gas industries. Mechanical drive applications increase efficiency by around 2%.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2016
Categories |