5
GE LM2500 – Operational data
• Power turbine output: ~ 22 MW• Thermal efficiency: ~ 37 %• Pressure ratio: 18:1• HP turbine inlet temperature (TIT): 1270 K• HP Turbine speed: 9700 rpm• Power turbine speed: 3600 rpm
The turbine parts are exposed to high temperaturesand mechanical stress resulting in deterioration
6
TurbineB
lade
spee
dCompressor
Mechanical energy
Kinetic energy
Pressure
Bla
desp
eed
Pressure
Kinetic energy
Mechanical energy
7
T3
Inlet/outler pressure
Combustor pressure
• GT cycle characterized by pressure ratio and turbine inlet temperature, T3
• Increased turbine inlet temperature, T3, increases thermal efficiency and power output
Comp.
Comb.
Turb1 4
32T3
The Gas Turbine Cycle
4 2 1
2
4 2 1
3
3 2
3
3 (
shaft
fuel fuel LHV
p p
p
P h h hEff
hh
T
iciencym H h
c T cc T
T TT
ideal gas)
4 2 13p pPower output m c T c T TT (ideal gas)
9
Operational conditions
Frequent starts/stops – thermal stress
Rapid changes in loading - high turbine inlet temperature and deterioration rate
Humid environment - salt deterioration
Stable loads – low deterioration rate
10 Snøhvit - Gas turbine system
Filter house Inlet duct,
silencer
Gas turbine Exhaustduct
Bleed duct
Ventduct
14.1 m
22.4 m
13
1
2 34
5
6
7
Startmotor
Innløp
Sentrifugalkompressor
Diffusor
1.turbin
(Legg merke til at de to turbinene er frikoplet, dvs. 2 akslinger)
2.turbin (kraftturbin)
Eksoskanal
Aksling til generator
• Arbeidsmediet er luft som opptrer som ideell gass• Temperaturløftet som skjer på grunn av forbrenningen er
presentert som en varmeoverføring fra en ekstern kilde.