Turbinas Gas
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TURBINAS A GÁS Prof. Paulo Cesar C. Pinheiro Dept. Engenharia Mecânica da UFMG Abril 2012 Introdução The combustion (gas) turbines being installed in many of today's natural-gas- fueled power plants are complex machines, but they basically involve three main sections: * The compressor, which draws air into the engine, pressurizes it, and feeds it to the combustion chamber at speeds of hundreds of miles per hour. * The combustion system, typically made up of a ring of fuel injectors that inject a steady stream of fuel into combustion chambers where it mixes with the air. The mixture is burned at temperatures of more than 2000 degrees F. The combustion produces a high temperature, high pressure gas stream that enters and expands through the turbine section. * The turbine is an intricate array of alternate stationary and rotating aerofoil- section blades. As hot combustion gas expands through the turbine, it spins the rotating blades. The rotating blades perform a dual function: they drive the compressor to draw more pressurized air into the combustion section, and they spin a generator to produce electricity. Introdução Land based gas turbines are of two types: (1) heavy frame engines (2) aeroderivative engines. Heavy frame engines are characterized by lower pressure ratios (typically below 20) and tend to be physically large. Pressure ratio is the ratio of the compressor discharge pressure and the inlet air pressure. Aeroderivative engines are derived from jet engines, as the name implies, and operate at very high compression ratios (typically in excess of 30). Aeroderivative engines tend to be very compact and are useful where smaller power outputs are needed. As large frame turbines have higher power outputs, they can produce larger amounts of emissions, and must be designed to achieve low emissions of pollutants, such as NOx. Introdução One key to a turbine's fuel-to-power efficiency is the temperature at which it operates. Higher temperatures generally mean higher efficiencies, which in turn, can lead to more economical operation. Gas flowing through a typical power plant turbine can be as hot as 2300 degrees F, but some of the critical metals in the turbine can withstand temperatures only as hot as 1500 to 1700 degrees F. Therefore, air from the compressor might be used for cooling key turbine components, reducing ultimate thermal efficiency. Another way to boost efficiency is to install a recuperator or heat recovery steam generator (HRSG) to recover energy from the turbine's exhaust. A recuperator captures waste heat in the turbine exhaust system to preheat the compressor discharge air before it enters the combustion chamber. A HRSG generates steam by capturing heat from the turbine exhaust. These boilers are also known as heat recovery steam generators. High-pressure steam from these boilers can be used to generate additional electric power with steam turbines, a configuration called a combined cycle.
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turbina a gás
Transcript of Turbinas Gas
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TURBINAS A GS
Prof. Paulo Cesar C. PinheiroDept. Engenharia Mecnica da UFMG
Abril 2012
IntroduoThe combustion (gas) turbines being installed in many of today's natural-gas-fueled power plants are complex machines, but they basically involve threemain sections:
* The compressor, which draws air into the engine, pressurizes it, and feedsit to the combustion chamber at speeds of hundreds of miles per hour.
* The combustion system, typically made up of a ring of fuel injectors thatinject a steady stream of fuel into combustion chambers where it mixes with theair. The mixture is burned at temperatures of more than 2000 degrees F. Thecombustion produces a high temperature, high pressure gas stream that entersand expands through the turbine section.
* The turbine is an intricate array of alternate stationary and rotating aerofoil-section blades. As hot combustion gas expands through the turbine, it spins therotating blades. The rotating blades perform a dual function: they drive thecompressor to draw more pressurized air into the combustion section, and theyspin a generator to produce electricity.
IntroduoLand based gas turbines are of two types:
(1) heavy frame engines(2) aeroderivative engines.
Heavy frame engines are characterized by lower pressure ratios (typicallybelow 20) and tend to be physically large. Pressure ratio is the ratio of thecompressor discharge pressure and the inlet air pressure.
Aeroderivative engines are derived from jet engines, as the name implies,and operate at very high compression ratios (typically in excess of 30).Aeroderivative engines tend to be very compact and are useful wheresmaller power outputs are needed.
As large frame turbines have higher power outputs, they can produce largeramounts of emissions, and must be designed to achieve low emissions ofpollutants, such as NOx.
IntroduoOne key to a turbine's fuel-to-power efficiency is the temperature at which itoperates. Higher temperatures generally mean higher efficiencies, which inturn, can lead to more economical operation. Gas flowing through a typicalpower plant turbine can be as hot as 2300 degrees F, but some of thecritical metals in the turbine can withstand temperatures only as hot as1500 to 1700 degrees F. Therefore, air from the compressor might be usedfor cooling key turbine components, reducing ultimate thermal efficiency.
Another way to boost efficiency is to install a recuperator or heat recoverysteam generator (HRSG) to recover energy from the turbine's exhaust. Arecuperator captures waste heat in the turbine exhaust system to preheatthe compressor discharge air before it enters the combustion chamber. AHRSG generates steam by capturing heat from the turbine exhaust. Theseboilers are also known as heat recovery steam generators. High-pressuresteam from these boilers can be used to generate additional electric powerwith steam turbines, a configuration called a combined cycle.
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Turbina LM500
Turbina LM5000 General MotorsComprimento 6,2mPeso: 12,5 tPotncia: 55,2 MW (injeo de vapor)
Combustveis Lquidos e Gasosos
3.5
10 20 40 50 60 7030
Medium Calorific Value (MCV) High Calorific Value(HCV)NormalSIT Ltd.
DefinitionLow CalorificValue (LCV)
PipelineQuality NG
Wellhead / Associated Gases
37 49 6515
60 % - 25 %Inerts (CO2,
N2)
90%-60 %Inerts
(CO2, N2)
Very lowinerts, high
hydrocarbons(CnHn+2 etc)
LNG High Inert
Wobbe Index (WI) is the main indicator of interchangeability of fuel gases.WI = Higher heating value/(square root of gas specific value)Wellhead gas and associated gases cover Wobbe Index from HCV to LCV withincreasing contents of inert gases (rare gases)WI-range of standard pipeline quality gas from 37 to 49MJ/Nm3
Conjunto das Turbinas a Gs
Compressor Train Turbines / Drives Industrial PowerPlants
CombinedCycle Power
Plants
Gas Turbine
SteamTurbine
ElectricDrive
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Turbinas a Gs Siemens
340279
266198
188163
12168
4529
2517
13875
SGT5-8000H
SGT5-4000F
SGT6-6000G
SGT6-5000F
SGT5-3000E
SGT5-2000E
SGT6-3000E
SGT-1000F
SGT-800
SGT-700
SGT-600
SGT-500
SGT-400
SGT-300
SGT-200
SGT-100 >3,900 gas turbines sold to date
Dry Low Emission Combustion System
SGT-300SGT-200
SGT-400
SGT-100
SGT-100 to SGT-400 Common Design
First DLE unit introduced 1995
335 DLE units now in service
7,315,000 DLE running hours to date
Double SkinImpingementCooledCombustor
Main Burner
PilotBurner
Igniter
Turbina Rolls Royce Trend 60
58 MW, Rendimento 42%
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FIM
