GAS TURBINE COMBUSTOR COMPRESSOR HEAT RECOVERY STEAM … · Natural gas, injected at a pressure of...
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GAS TURBINE: 36–40% efficiency STEAM TURBINE: 16–20% efficiency OVERALL EFFICIENCY OF THE COMBINED CYCLE: 52–60% About 52–60% of each 1 MWh of energy is turned into electric power, which means it generates 0.52–0.6 MWh of electricity. COMPRESSOR The compressor compresses air from its normal pressure of around 1 bar to 17.2 bar. GENERATOR The gas turbine spins the generator at 3,000 rpm, which generates electricity at a voltage of 19 kV. GENERATOR The gas turbine spins the generator at 3,000 rpm, which generates electricity at a voltage of 19 kV. TRANSFORMER Voltage of the three-phase alternating current produced by the generator is increased by transformers to 220 kV, and then fed into the national power grid. COMBUSTOR Natural gas, injected at a pressure of 30 bar, and compressed air join here. The gas and air are mixed and burned, producing combustion gases which have a temperature of about 1,500°C and a pressure of 17 bar. HEAT RECOVERY STEAM GENERATOR The heat of the combustion gases exiting the gas turbine can be utilized by producing steam in the heat recovery steam generator. Incoming water is heated up and vaporized into steam by the cooling combustion gases. STEAM TURBINE The steam turbine is spun/driven (at 3,000 rpm) by steam which exits the heat recovery boiler at a temperature of 550°C. Here, just as in the gas turbine, thermal energy is converted into kinetic energy. STEAM TURBINE Wet steam exiting the steam turbine cannot produce useful work, and therefore needs to be condensed back to liquid state. This is done by the cooling water circulating in the condenser's pipes. WATER COOLING (ONCE-THROUGH COOLING, OTC) The condenser needs a continuous supply of water, which means that "raw" water is taken from a river. In areas with limited water supply Heller-Forgó type cooling towers are used. GAS TURBINE The hot flue gases exiting the combustor spin the gas turbine. The gas turbine rotates at 3,000 revolutions per minute (rpm) and is mounted on the same shaft with the generator and compressor. The turbine's kinetic energy is used partly to run the compressor, and partly to spin the generator. Exhaust gases exit the turbine at a temperature of 560°C and a pressure of 1.5 bar.
Transcript of GAS TURBINE COMBUSTOR COMPRESSOR HEAT RECOVERY STEAM … · Natural gas, injected at a pressure of...
GAS TURBINE: 36–40% e�ciency STEAM TURBINE: 16–20% e�ciency OVERALL EFFICIENCY OF THE COMBINED CYCLE: 52–60%
About 52–60% of each 1 MWh of energy is turned into electric power, which means it generates 0.52–0.6 MWh of electricity.
COMPRESSORThe compressor compresses air from its
normal pressure of around 1 bar to 17.2 bar.
GENERATORThe gas turbine spins the
generator at 3,000 rpm, which generateselectricity at a voltage of 19 kV. GENERATOR
The gas turbine spins thegenerator at 3,000 rpm, which generates
electricity at a voltage of 19 kV.
TRANSFORMERVoltage of the three-phase alternating current producedby the generator is increased by transformers to 220 kV,
and then fed into the national power grid.
COMBUSTORNatural gas, injected at a pressure of 30 bar, and compressed
air join here. The gas and air are mixed and burned, producingcombustion gases which have a temperature of about
1,500°C and a pressure of 17 bar.
HEAT RECOVERYSTEAM GENERATOR
The heat of the combustion gases exiting the gas turbinecan be utilized by producing steam in the heat recovery
steam generator. Incoming water is heated up andvaporized into steam by the cooling combustion gases.
STEAM TURBINEThe steam turbine is spun/driven (at 3,000 rpm) by steam
which exits the heat recovery boiler at a temperature of 550°C.Here, just as in the gas turbine, thermal energy is converted into
kinetic energy.
STEAM TURBINEWet steam exiting the steam turbine cannot
produce useful work, and therefore needsto be condensed back to liquid state.
This is done by the cooling water circulatingin the condenser's pipes.
WATER COOLING(ONCE-THROUGH COOLING, OTC)
The condenser needs a continuous supply of water, which meansthat "raw" water is taken from a river. In areas with limited
water supply Heller-Forgó type cooling towers are used.
GAS TURBINEThe hot �ue gases exiting the combustor spin the gas turbine. The gas turbine rotates
at 3,000 revolutions per minute (rpm) and is mounted on the same shaft withthe generator and compressor. The turbine's kinetic energy is used partly to run the
compressor, and partly to spin the generator. Exhaust gases exit the turbine ata temperature of 560°C and a pressure of 1.5 bar.
