kap 9: gas power systems gassturbin olav bolland - ntnu av slides/slides-kap9... · 3 bolland gas...
Post on 07-Apr-2018
228 Views
Preview:
TRANSCRIPT
1
Bolland
Kap 9: Gas Power SystemsGassturbin
Olav Bolland
TEP4115/4120 Termodynamikk
2
Bolland
Power production in Norway
• National grid: 99.5% hydropower– 27000 MW - 120 TWh/a– Per capita: 6 kW - 27000 kWh/a
• Offshore oil/gas: mechanical power and local grids– 3000 MW gas turbine power - 10 TWh/a
• Future:– Wind power: 2002-2010 +3 TWh/a (2010: 0.9 TWh!!)– More hydropower: potential YES – acceptance NO– Natural gas power: potential YES
problem is CO2
– CO2 is a hot issue!!– Dependence on import of coal & nuclear power?
3
Bolland
Gas Turbines
Assumptions for the basic gas turbine cycle:• Air, as an ideal gas, is the working fluid throughout• Combustion is replaced with heat transfer from an external source
Fig. 9.8, page 389
4
Bolland
Gas Turbine Applications• Aero Engines (jet, turbofan, turboprop)• Gas Pipelines (compressor driver)• Power plants (generator driver)• Combined Heat and Power (generator, utilisation of exhaust heat)• Ship Propulsion• Oil/Gas-Platforms (generator & compressor driver)• Others (emergency backup, desalination)
• 2000: Production value of aero engines larger than for gas turbines for power generation and mechanical drive
• 2001 : Production value of gas turbines for power generation and mechanical drive larger than for aero engines
Annual production value of gas turbines/aero engines: 50 bill. US$
5
Bolland
General Electric LM5000Laget med utgangspunkt i flymotor
6
Bolland
Cutaway diagram of a Westinghouse 501D5A gas turbine
7
Bolland
Siemens V94.2ca. 150 MW,
første gassturbin med lav-NOXNOX = (NO/NO2) = nitrogenoksider
8
Bolland
Turbin i gassturbin4-trinns, Siemens
1. trinns løpeskovler
1. trinns ledeskovler
Ringbrennkammer(brennerne kan ikkesees, bak til høyre)
9
Bolland
Work closed/open systems
2 1
2
1
2 2 2
1 1 1
2
2 1 2 11
2
1
First law for a closed system:
Relating heat to entropy:
Q W U U
Q T dS
T dS dU PdV
Q T dS dU pdV
U U pdV W U U
W pdV
1 2
2 2 2
1 1 1
2 2
1 1
2 2
1 1
First law for an open system (steady-state):
0
Relating heat to entropy:
and and
dUQ W mh mh
dt
Q T dS dU pdV
T dS dU PdV T dS dH Vdp
H U pV dU dH pdV Vdp
Q dH V dp
Q m dh V dp
2
2 1 1 21
2
1
( ) ( ) 0m h h V dp W m h h
W V dp
10
Bolland
The Brayton CycleCycle Analysis:
12
1 2
Wh h
m
233 2
Qh h
m
411 4
Qh h
m
34
3 4
Wh h
m
Fig. 9.9, page 389
11
Bolland
Ideal Brayton Cycle
Using Constant Specific Heats, the cycle thermal efficiency is:
1
2
1
11 k
kpp
Fig. 9.10, page 391
Fig. 9.11, page 394
12
Bolland
Ideal Brayton Cycle, different pressure ratios
Fig. 9.12, page 395
13
Bolland
Irreversibilities in a gas turbine cycle
Fig. 9.13, page 397
14
Bolland
Regenerative/recuperative Gas Turbines
2
4 2
xreg
h h
h h
Fig. 9.14, page 400
Største gassturbin med rekuperatorer Rolls Royce WR21 (20 MW, in UK Type 45 destroyer)Rekuperator benyttes typisk på små GT, 100-500 kW.
15
Bolland
Reheat and Intercooling
Fig. 9.16, page 404
Reheat, regeneration, and intercooling are most effective when used in combination with one another. However, weight limitations (e.g. aircraft applications) often limit their usage.
Fig. 9.18, page 407
Alstom GT26/GT24 (277/191 MW, 3000/3600 rpm)er de eneste gassturbiner som benytter reheat.Alstom bruker begrepet ”sequential combustion”.
16
Bolland
Aircraft Applications
Turbo Jet Applications, with and without afterburner
Fig. 9.20, page 414
Fig. 9.21, page 415
17
Bolland
Turbo jet – with afterburner
18
Bolland
Aircraft Applications
a) Turboprop, b) Turbofan, and c) Ramjet applications
< 600 km/t
< 1000 km/t
19
Bolland
Turbofan
GE90B777-300ER
20
Bolland
RakettmotorRomferge; i brun tank: oksygen hydrogen
21
Bolland
Compressible Flows: The Basics
2 1F V Vm
1-D Steady Flow Momentum Equation:
Velocity of Sound, isentropic wave, ideal gas: c kRT
Mach Number:V
Mc
Stagnation Enthalpy:
2
0 2
Vh h
22
Bolland
Fig. 9.23, page 419
Combined Cycle
23
Bolland
Hvorfor har en kombinert prosesshøy virkningsgrad ?
CARNOTl
h
T
T 1
Carnotvirkningsgrad; en kvalitativ beskrivelse av virkningsgrad for en kraftprosessTl er temperatur for varmeavgivelse fra prosessenTh er temperatur for varmetilførsel for prosessen
T
s
Th
Tl
Th h
s sh
3 2
3 2lav -
1
2
3
4
Th h
s sl
4 1
4 1lav
Dampturbin prosess
T
s
Th
Tl
Th h
s sh
3 2
3 2høy
1
2
3
4
Th h
s sl
4 1
4 1lav
Kombinert prosess
T
s
Th
Tl
Th h
s sh
3 2
3 2høy
1
2
3
4
Th h
s sl
4 1
4 1høy
Gassturbin prosess
24
Bolland
Utvikling av virkningsgrad for gassturbin-anlegg
1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 200620
25
30
35
40
45
50
55
60
65
70
Vir
knin
gsgr
ad [
%]
Kombinerte gassturbin-/dampturbinanleggFlyderiverte" gassturbinerStore industri-gassturbiner
Kombinerte gassturbin-/dampturbinanlegg
"Flyderiverte" gassturbiner
Store industri-gassturbiner
25
Bolland
Varmegjenvinning fra en eksosgass ved dampproduksjon
0
100
200
300
400
500
600
700
0 50 100 150 200 250 300 350
Overført varme [MW]Heat transfer
Tem
per
atu
r [C
]T
emp
erat
ure Eksos/
Exhaust
Vann/DampWater/steam
Eksosgasskurve,stigningstall 1/(m*cp)
Overheter,stigningstall 1/(m*cp)
fordamper,fordamping ved konstant temperatur
pinch,minste dT i kjel,begrensende fordampproduksjon
economiser,stigningstall 1/(m*cp)
26
Bolland
Components of a Vapor Power PlantSteam Power Plant
27
Bolland
Rankine Cycle
Turbine:
1 2tW
h hm
Condenser (1 side):
2 3outQ
h hm
Boiler:
1 4inQ
h hm
Pump:
4 3pW
h hm
Overall Performance:
1 2 4 3
1 4
/ /
/
t p
in
W m W m h h h h
h hQ m
28
Bolland
Combined Cycle Power Plant
29
Bolland
Gasskraftverk Kårstø - 420 MW
30
Bolland
Combined Cycle Power Plant
%5.48100
5.48
%5.89100
415.48
E
PE
QP
%57100
57
E
P
Power Production only Heat & Power Production
31
Bolland
Fuel characteristics for CO2-emission
Fossil fuels consists of the combustible componentsCarbon (C) and Hydrogen (H)
M ethane: C H1 4
The ratio between carbon and hydrogen gives the amount of CO2
C H O CO H O2 2 2m n
coal oil natural gas
coal oil natural gas
mn
mn
m
n
m
n
m
n
4 2
11 0 5 0 25. . .
32
Bolland
Emission of CO2 from fossil fuels
30 35 40 45 50 55 60 65 70 75 80 85 90 95 100Eff iciency [%]
0100200300400500600700800900
1000110012001300
Em
issi
on o
f gr
am C
O2 p
er k
Wh e Methane (H/C=4)
Distillate oil (H/C=2)Lignite (brown coal)Bituminous coalAnthrasit
33
Bolland
”CO2-fri” gasskraft?Mest kjente teknologiprinsipper
Navn/begreper for de tre metodene:1: Post-combustion2: Pre-combustion3: Oxy-combustion (eller oxy-fuel)
CO₂separation
CO₂ compression & conditioning
N₂/O₂
CO₂
ShiftH₂
CO₂
Powerplant
Air
O₂N₂
CO₂
N₂/O₂CO₂ compression
& conditioning
Powerplant
Gasification
Reforming
CO₂separation
H₂
CO₂
CO/H₂
Air separation
CO/H₂
Coa
l, O
il, N
atur
al G
as,
Bio
mas
s Powerplant
Post-combustion
Pre-combustion
Oxy-combustion
top related