Heavy Duty Gas Turbine Overview
Tra rain inin ing g Pro Progr gra am 1 - Gas Turbin Turbine e Gene nera rall Ove verview rview
Installation Installat ion layo layout ut Main equip eq uipmen mentt lo locat cation ion
2 - Ope pera rating ting Principles
Describe the gas turb Describe turbine ine thermodynamic thermodynam ic cycle, main paramete para meters rs and perf performa ormance nce
3 - GT Compon Compone ente ntes s Descri scription ption
Descri Desc ribe be in det detai aill all all ga gas s turbine componentes and their functions
Tra rain inin ing g Pro Progr gra am 1 - Gas Turbin Turbine e Gene nera rall Ove verview rview
Installation Installat ion layo layout ut Main equip eq uipmen mentt lo locat cation ion
2 - Ope pera rating ting Principles
Describe the gas turb Describe turbine ine thermodynamic thermodynam ic cycle, main paramete para meters rs and perf performa ormance nce
3 - GT Compon Compone ente ntes s Descri scription ption
Descri Desc ribe be in det detai aill all all ga gas s turbine componentes and their functions
Tra rain inin ing g Pro Progr gra am 4 - Main GT Auxilia Auxiliary ry Syste Systems ms
Describe the Auxi Describe Auxiliar liary y systems, P&ID
5 - Gas Turbine Contro Controll System System
Basic of Control and Protection Prote ction Syste System, m, StartStart-up up and Shut-down sequences
6 – Maint inte enance Overview Overview
Scheduled and Borescope Inspection, Disassembling and reassembling procedures, Components Componen ts acceptability criteria
Wha hatt is a Gas Turbin Turbine e?
Gas Turbin Turb ine e is an engine engin e as as a four cycle cy cle recipro reciproca cating ting engine •It’s •It’ s an hi high gh te tech chno nolo logy gy en engi gine ne •It’ an high speed rotating machine (3.000÷30.000 rpm) •In industrial application may drive generators (GD = Generator Drive) or pumps and compressors (MD = Mechanical Drive) •It’s used for mobile mobile application as aircraft ships etc. •Power range of gas turbine is between 100 kW and 350 MW •It’s efficiency is between between 25% and 40% •High specific power (light and powerful machine) •May use a large typology of fuels (gas and liquid types) •It may operate continuously without stop as long as for one year Ad A d d i t i o n al alll y f o r p o w er h i g h er t h an 500 kW k W it i t h as •Low cost of installed kw •Low maintenance costs
Wha hatt is a Gas Turb Turbine ine? ?
The Th e pri prima mary ry sc scop ope e is… is…..
To produce mechanical energy at low cost and continuously!!
How a Gas Tur urbi bine ne Wor Works ks IT DIRECTS HIGH PRESSURE, HIGH TEMPERATURE AIR TO THE TURBINE SECTION, WHICH CONVERTS FUEL
THERMAL ENERGY INTO MECHANICAL ENERGY THAT MAKES THE SHAFT REVOLVE; THIS SERVES, ON THE ONE HAND, TO SUPPLY USEFUL ENERGY TO THE DRIVEN
FUEL
MACHINE, COUPLED TO THE MACHINE BY MEANS OF A COUPLING AND, ON THE OTHER HAND, • IT EXHAUS EXH AUST T LOW PR ESSURE URE, , LOW TEMPERAT TEMPE RATURE URE TO SUPPLY ENERGY NECESSARY FOR AIR COMPRESSION, • IT PRESS INCREA INC REASES SES THE ENERGY ENE RGY LEVEL LEVE L
GASES RESULTING FROM THE ABOVE-MENTIONED TRANSFORMATION INTO THE ATMOSPHERE IT COMPRES COMP RESS S IT TO HIGH H IGHER ER PCHAMBER PRES RESSUR SURE E WHICH TAKES PLACE COMPRESSOR DIRECTLY WITH THE TURBINE SECTION OF THE COMPRESSED AIR• IN BY ADDING AND BURNING FUEL IN COMBUSTION IT A DR DRAWS AWS IN AIR F• ROM FROM THE THE SUR SURROUND ROUNDING ING E ENVIRO NVIRONMEN NMENT T.
Nuovo Pignone
GAS TURBINES GENERAL OVERVIEW
Gas Turbine Families HEAVY DUTY
SINGLE SHAFT
JET
TWO SH AFTS
“ PURE AEREONAUTICAL” “ PENGIUN TURBINES”
INDUSTRIAL & MARINE USE LM SERIES
INDUSTRIAL USE
INDUSTRIAL USE PGT/GE SERIES
Gas Turbines Product Range GE 5-1
5.5 MW
GE 55-2
5.6 MW
GE 1010-1 GE 1010-2 LM 1600/PGT 16 LM 2000/PGT 20 LM 2500/PGT 25 MS 5001 MS 5002C MS 5002E LM 2500+/PGT 25+ MS 5002D MS 6001B LM 6000 MS 7001EA MS 9001E
Solid Technology Base … ... For Every Application
11.2 MW 11.7 MW
High Efficiency, Reliability & Availability
14.2 MW
Low Life- Cycle Costs Application
18.1 MW
23.2 MW
Fuel Flexibility
26.3 MW
Flexibility
Low Emissions
28.3 MW 30.0 MW 31.3 MW 32.5 MW 42.1 MW 44.7 MW 85.1 MW 123.4 MW
Multi Shaft Single Shaft
PGT 5/1 KEY DATA • The PGT5/1 heavy-duty gas turbine has been designed with modular concepts to facilitate accessibility and maintainability. • The gas generator consists of a 15-stage, high efficiency, axial-flow compressor directly coupled to a two stage turbine. • The PGT5 has a single combustion chamber system which is rugged, reliable and able to burn a wide range of fuels, from liquid distillates and residuals to all gaseous fuels, including low BTU gas. • It is specially designed for small power generation and cogeneration
PERFORMANCE (@ ISO CONDITIONS; MD) : 5.220 Kw Output : 26,9 % Efficiency : 13.422 kJ/kWh Heat Rate : 24,6 kg/s Ex. Gas Flow : 524 °C Ex. Gas Temp. : 11.140 rpm Nominal Speed
Weight:
28.000 Kg
PGT 5/2 KEY DATA • The PGT5/2 heavy-duty gas turbine has been designed with modular concepts to facilitate accessibility and maintainability. • The gas generator consists of a 15-stage, high efficiency, axialflow compressor directly coupled to a single stage turbine. • The low pressure shaft is a single-stage, high-energy turbine, with variable second stage nozzles which grant maximum flexibility for mechanical drive service. • The PGT5/2 has a single combustion chamber system which is rugged, reliable and able to burn a wide range of fuels, from liquid distillates and residuals to all gaseous fuels, including low BTU gas. • Typical applications include pump drive for oil pipelines and compressor drive for gas pipelines. Also used in PG
PERFORMANCE (@ ISO CONDITIONS; GD & MD) Output : 5.450 Kw : 26,9 % Efficiency : 13.422 kJ/kWh Heat Rate : 24,6 kg/s Ex. Gas Flow : 524 °C Ex. Gas Temp. : 11.140 rpm Nominal Speed
Weight:
28.000 Kg
GE 5/1 KEY DATA • Single Shaft ideal Prime Mover for Industrial Cogeneration • 50Hz or 60Hz Power Generation • 11 stage Compressor scaled from GE10 • DLE Combustion System • High Reliability & Maintainability • Compact Package • Low Maintenance Cost.
PERFORMANCE (@ ISO CONDITIONS; MD)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 5.500 : 30,7 : 11.740 : 19,6 : 574 : 16.630
Kw % kJ/kWh kg/s °C rpm
Weight:
23.900 Kg
GE 5/2 (New Product) KEY DATA • Twin Shaft driver for Centrifugal Compressors and Pumps • 3D Aero • Advanced static and brush seals • New coatings • Advanced compressor design • Optimization of clearances
PERFORMANCE (@ ISO CONDITIONS)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 5.600 : 31,5 : 11.428 : na : na : na
Kw % kJ/kWh kg/s °C rpm
Weight:
24.000 Kg
PGT 10 A (two shaft) KEY DATA • The PGT10 A/2 design goals are: high performance, high reliability and availability, easy maintenance concepts. • High technology design: High pressure ratio, firing temperature level in line with second generation gas turbines, variable axial compressor stator vanes and power turbine nozzles. • The PGT10 combustion system consists of a single combustion chamber suitable for a large variety of gaseous and liquid fuels. • Typical applications for PGT10 are natural gas compression, centrifugal pump drive and process application, Offshore applications.
PERFORMANCE (@ ISO CONDITIONS)
MD
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: 10.660 : 32,5 : 11.250 42,3 : : 493 : 10.800
GD 10.220 Kw 31,4 % 11.540 kJ/kWh 42,1 kg/s °C 484 10.800 rpm
Weight:
34.000 Kg
GE 10/1 KEY DATA • Derivative of PGT10A - 2.000.000+ hours experience • High efficiency high pressure ratio Compressor with less stages - 11 Vs 17 • DLN combustion system available • Good Reliability & Maintainability • Low maintenance cost • Model available may Have combustion chamber horizontal or vertical according customer request
PERFORMANCE (@ ISO CONDITIONS; GD)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 11.250 : 31,4 : 11.481 : 47,5 : 482 : 11.000
Kw % kJ/kWh kg/s °C
rpm
Weight:
34.000 Kg
GE 10/2 KEY DATA • Turbine designed and developed by Nuovo Pignone Since reliability and availability to worldwide customers while keeping with easy maintenance concepts. • Two shafts for mechanical drive and single shaft for power generation and cogeneration applications. • The GE10 Gas Turbine, with its ability to burn different fuels (natural gas, distillate oil, low BTU fuel), can be installed in many countries with different environmental conditions continental, tropical, offshore and desert. • Oxides (NOx) reduction in order to meet present and future standards for pollutant emissions. Weight:
PERFORMANCE (@ ISO CONDITIONS; MD)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 11.615 32,5 : : 11.121 46,9 : 488 : : 7.900
Kw % kJ/kWh kg/s °C
rpm
40.000 Kg
PGT 16 KEY DATA • First unit in operation 1991 • Based on proven LM 1600 GG and NP developed heavy duty power turbine • High efficiency • Proven reliability in MD and PG applications • Effective DLE system This turbine use some power turbine of PGT 10/A and GE 10/2
PERFORMANCE (@ ISO CONDITIONS) MD
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: : : : : :
14.252 36,2 9.939 47,4 493 7.900
GD 13.735 34,9 10.314 47,4 493 7.900
Kw % kJ/kWh kg/s °C rpm
Weight:
19.000 Kg
PGT 25 KEY DATA • Power Turbine developed by Nuovo Pignone in the early ‘80s • First unit installed in 1983 • M.D. & P.G. fleet firing hours exceed 1,800,000
PERFORMANCE (@ ISO CONDITIONS) MD Output
: Efficiency : Heat Rate : Ex. Gas Flow : Ex. Gas Temp. : PT Nominal Speed :
23.261 (shaft) 37,7 (shaft) 9.560 (shaft) 68,9 525 6.500
GD Kw 22.417 (el.) % 36,3 (el.) 9.919 (el.) kJ/kWh kg/s 68,9 C 525 rpm 6.500
Weight:
38.000 Kg
PGT25 Power Turbine
PGT 25+ KEY DATA • Designed by Nuovo Pignone using G.E. LM 2500 Plus gas generator • The PGT 25 + is a last generator, 30 MW size • First unit in operation during 1997 • Fleet firing hours exceed 100,000
PERFORMANCE (@ ISO CONDITIONS – MD & PG)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: 31.364 41,1 : : 8.754 84,3 : 500 : : 6.100
Kw % kJ/kWh kg/s °C rpm
Natural Gas Fuel
Dry Operation
Base Load
(no steam or water injection)
MS 5001
KEY DATA
• The MS5001 single shaft turbine is a compact heavyduty turbine designed for long life and easy maintenance. • The MS5001 gas turbine is the ideal solution for industrial power generation where low maintenance, reliability and economy of fuel utilization are required. • Low investment costs make the MS5001 package power plant an economically attractive system for peak load generation. • The MS5001 is ideally suited for cogeneration achieving very high fuel utilization indexes • Typical applications are industrial plants for cogeneration of power and process steam or in district heating systems.
PERFORMANCE (@ ISO CONDITIONS; GD)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 26.300 26,3 : : 12.650 : 124,1 487 : : 5.100
Kwe % kJ/kWh kg/s °C rpm
Weight:
87.430 Kg
MS 5002C / MS 5002D KEY DATA • Low capital & maintenance cost • Long maintenance intervals • Fleet leader in excess of 100.000 running hours • More than 420 units worldwide
PERFORMANCE (@ ISO CONDITIONS) MS5002C
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: : : : : :
28.340 28,8 12.470 124,3 517 4.670
Weight:
MS5002D 32.580 29,4 12.239 141,4 509 4.670
Kw % kJ/kWh kg/s °C rpm
110.000 Kg
MS5002E (New Product) Features • • • • •
Leverage GE Technology Moderate Firing Temperature Reliability & Efficiency as Key Factors DLN System derived from large Frames Twin Shaft - suitable for MD or PG
Rotordynamic Test
Introductory Performance
Output Shaft SC Efficiency LPT shaft speed Exhaust Temp. NOx Emission
30 MW : : 36,4 % : 6.100 rpm : 523 °C 25 ppm :
CTV Test Ri g CTV Compressor Test
Weight:
117.000 Kg
LM 6000 KEY DATA • • • •
Most efficient GT in its class Proven high reliability and availability Generator & Mechanical drive applications 3 + millions cumulating operating hours
PERFORMANCE (@ ISO CONDITIONS – PG; MD) Weight:
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: : : : : :
43.076 41,3 8.707 131,0 449 3.600
kW % kJ/kWh kg/s °C rpm
31.000 Kg
MS 6001 B KEY DATA • The MS6001 is a single shaft heavy-duty gas turbine. Its design was based on the well proven mechanical features of the MS5001 in order to achieve a compact, high efficency unit. • The MS6001 is widely applied in power generation applications for base, mid-range and peak load service. • Other typical applications include driving of process machines, such as compressors, in LNG plants. • Combined cycle plants based on MS6001 achieve very high efficiencies with higher availability and reliability.
Weight:
PERFORMANCE (@ ISO CONDITIONS) MD GD Output Efficiency Heat Rate
kJ/kWh Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: : :
43.530 (shaft) 33,1 (shaft) 10.852 (shaft)
42.100 (el.) 32,06 (el.) 11.230 (el.)
: : :
145 544 5.133
145,8 552 5.100
Kw %
kg/s °C rpm
96.000 Kg
MS 7001 EA KEY DATA • The MS7001EA is a single shaft heavy-duty gas turbine for power generation and industrial applications requiring the maximum reliability and availability. • With design emphasis placed on energy efficiency, availability, performance and maintainability, the • MS7001EA is a proven technology machine with more than 500 units of its class in service. • Typical applications in addition to the 60Hz power generation service are large compressor train drives forLNG plants.
PERFORMANCE (@ ISO CONDITIONS) MD GD Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. Nominal Speed
: 81.590 (shaft) : 32,67 (shaft) : 11.020 (shaft) kJ/kWh : 278 : 546 : 3.600
85.100 (el.) 32,73 (el.) 11.000 (el.) 300 537 3.600
Weight:
Kw %
kg/s °C rpm
121.000 Kg
MS 9001 E KEY DATA • The MS9001E is a single shaft heavy-duty gas turbine. • It was developed for generator drive service in the 50 Hertz market. • The MS9001E is widely applied in power generation for base, mid-range and peak load service. • Combined cycle plants based on MS9001E achieve very high efficiencies with higher availability and reliability than conventional thermal plants. • Newest field of application is LNG for MD
Weight:
PERFORMANCE (@ ISO CONDITIONS – PG & MD)
Output Efficiency Heat Rate Ex. Gas Flow Ex. Gas Temp. PT Nominal Speed
: : : : : :
126.100 33,8 10.650 418 543 3.000
kW % kJ/kWh kg/s °C rpm
217.500 Kg
MS 9001 FA
MS 9001 H
Output Range
Nuovo Pignone
32,5 Mw
26 Mw
OUTPUT POWER
29 Mw
23,2 Mw
14 Mw 10,5 Mw
6 Mw 5 Mw
12 Mw
For any fu rther need, please find NP on Internet at the following andress:
2 Mw
http://www.gepower.com/nuovopignone
Load Applic.
Gas Turbines Service according load type
SINGLE SHAFT GAS TURBINES
DOUBLE SHAFT GAS TURBINES
HD GT Families
Heavy Duty Gas Turbine Families HEAVY DUTY
SINGLE SHAFT
TWO SHAFTS
INDUSTRIAL USE
GT Applic. Field
Gas Turbines Applications
Gas Booster, Pipeline and Re-injection
Liquified Natural Gas Plants
Petrochemical Plants
Gas Turbines produced by GE Energy
Power Generation and Cogeneration Plants
District Heating Offshore Applications
Gas Turbines Typical Loads
Centrifugal and Axial Compressors
Reciprocating Compressors
Electric Generators GE Energy Gas Turbines
Centrifugal Pumps
Nuovo Pignone
GAS TURBINES OPERATING PRINCIPLES
KEY TERMS
ISO conditions
Gas Turbine performance are declared in ISO condition and the constructors have to declare fuel used to obtain declared performances.
ISO conditions
Ambient Pressure:
101.325 Pa (14,7 P.S.I.A.)
Ambient Teperature:
15 °C (59 °F)
Relative Humidity:
60%
Pressure drop in inlet/exhaust:
0 mm H2O
They are the conditions to refer for GT performances evaluation
FIRING TEMPERATURE
Section A refers the so called “TURBINE INLET TEMPERATURE”, wich is the average temperature of hot gas at plane A. Section C refers to the so-called “ISO FIRING TEMPERATURE”, wich is the average gas temperature at plane C, calculated as a function of the air and fuel flow rates via a thermal balance of combustion according to the ISO 2314 procedure.
FIRING TEMPERATURE According to the NUOVO PIGNONE-GENERAL ELECTRIC standard, the temperature that best represents point (3) is the one in section B The difference in the interpretation of temperatures in section A and B consists in the fact that the section B temperature takes account of mixing with 1st stage nozzle cooling air, wich was not involved in the combustion process, but mixes with burnt gases after cooling the surface of the nozzle.
T
3
2 4
1
P
S
2
3
1
4
V
PRESSURE RATIO
HEAT RATE P
2
T
3
3 2
4
1
4
HR =
1
S
V
2 4
3
1
Q1 Lu
Heat Rate is the inverse of efficiency, in that it indicates the ratio between thermal energy, resulting from the combustion process, and mechanical energy, obtained on the power shaft.
In generally expressed as kj/kWh
POWER & HEAT RATE
HEAT RATE THERMAL ENERGY THAT WE SPEND TO PRODUCE 1 UNIT OF MECHANICAL ENERGY
Power & Heat Rate
HEAT RATE HEAT RATE IS THE INVERSE OF EFFICIENCY
Power & Heat Rate
If we think about a car, HEAT RATE is…
LOW HEAT RATE
MUCH MONEY FOR OUR COMPANY
Power & Heat Rate
HIGH POWER & LOW HEAT RATE
MUCH MONEY FOR OUR CUSTOMERS
COMPRESSOR RATIO
BRAYTON CYCLE Fuel
Air 1 Intake
Exhaust
4
CC
3
C - Compressor CC - Combustion T - Turbine L - Load
2
T
C
P
Combustion
2
Expansion
L
T
3
3
2 1 Compression
4 Exhaust
4
1
V
S
Specific Compression Work
Wc = c pm (T 2
T 1 ) ×
−
(T 2 − T 1 )
Mesured in
Kj kg inlet _ air 2 4
3
1
Cpm=average specific heat at costant pressure
Specific Expansion Work
Wt = c pm (T 3
−
T 4 ) ×
(T 3 − T 4 )
Mesured in
Kj kg gas 2 4
3
1
Cpm=average specific heat at costant pressure
Heat supplied to the combustion chamber
Q1
=
c pm (T 3
−
T 2 ) ×
(T 3 − T 2 )
Mesured in
Kj kg gas 2 4
3
1
Cpm=average specific heat at costant pressure
Heat suppl. to atmosphe tmosphere re with exha exhauste usted d ga gas s
Q2
=
c pm (T 4
−
T 1 ) ×
(T 4 − T 1 )
Mesured in
Kj kg ehxaust _ gas 2 4
3
1
Cpm=average specific heat at costant pressure
The herm rmod odyn yna ami mic c eff ffic icie ienc ncy y 2 4
3
η cl 1
η T
=
f (η T ;η C ;η CC ;η cl ...)
=
(Q1 − Q2 ) Q1
This equation tell us that, t hat, by pa p arit rity y of hea heat Q1, introdu introduce ced d into the combustion combus tion cha chambe mberr by b y fue f uel, l, effi fficiency ciency will incr i ncre ease as hea heat Q2 “ dissip dissipa ate ted” d” into the atmosphe tmosphere re decreases
Use seful ful work supp supplie lied d to the driv drive en machin machine e
Pu
=
(Gair + G fuel ) × W t − Gair × W c
Meas Me asur ured ed in
2 4
Kj s
3
1
Gair = amo amoun untt of ai air r Gfuel= amo amoun untt of fue fuell
MAIN PARAMETERS AFFECTING G.T. PERFORM.
In the Brayton Cycle the following parameters are very important :
T
3
2 4
FIRING TEMPERATURE PRESSURE RATIO
P2
T 3 1
P1
P
THERMAL EFFICIENCY
S
2
3
SPECIFIC POWER Kw (kg ) s
1
4
V
Brayton Cycle: P1, P2 P1
P2
Brayton Cycle: T1, T2 and T3 T3=?
T1 T2
Brayton Cycle: T3 T3=f(T4,P2)
ß=10,5
963°C (1765°F)
Brayton Cycle: T4
Single and Double shaft: differences to use
…PROBLEM IS IN THE AXIAL COMPRESSOR OF HEAVY DUTY GAS TURBINES…
G.T. for Generator Drive (mainly): Single shaft
Single shaft G.T. are preferred to drive Generators
SINGLE SHAFT GAS TURBINES MUST ROTATE AT CONSTANT SPEED (i.e. 5100 rpm for MS5001/6001, 3600 rpm for MS7001 and 3000 rpm for MS9001) TO AVOID SURGE OR STALL PROBLEMS ON ITS INTERNAL AXIAL COMPRESSOR SINGLE SHAFT GAS TURBINES HAVE BEEN MAINLY DEVELOPED TO DRIVE ELECTRICAL GENERATORS BECAUSE THE GENERATOR IS A MACHINE THAT NEEDS TO ROTATE AT CONSTANT SPEED
Single Shaft G.T. Schematic AIR
4
COMBUSTORS
1
COMBUSTIBILE
EXHAUST GAS
3
STARTING MOTOR
AXIA L
2
LOAD
COMPRESSOR
AUXIL IARY GEARBOX TURBINE
1-2 AIR COMPRESSION 2-3 COMBUSTION 3-4 EXPANSION
60 MW (50%)
120 MW (100%)
60 MW (50%) *
*typical value for HD GT
LOAD: Electric Generator (often), Compressor, Pumps (rarely)
AUXILARY GEAR BOX Drives Auxiliaries (mainly Oil Pumps) and transmits torque from Starting Device
Single Shaft Gas Tubines for GD HEAVY DUTY Single Shaft G.E. Gas Turbine Production Range MS 1001 (*) PGT 2 (*) PGT5/1 GE 5/1 GE 10/1 MS 5001 MS 6001 (**) MS 7001 (**) MS 9001 (**) (*) Out of produ cti on, Upgrade are available
SINGLE SHAFTS
(**) These units are also used in mechanical dri ve application s wh ere constant sp eed i s r equired (i.e. LNG compression plants)
Gas Tubines for Mechanical Drive: Two shafts
Two shafts Heavy Duty type is better to drive loads requiring speed changes infact …
IF WE NEED TO DRIVE….
Two shafts can provide high speed range variation..
… AS MS 5002, WHERE THE HP ROTOR (ROTOR OF AXIAL COMPRESSOR) CONTINUE TO WORK AT CONSTANT SPEED (5.100 rpm), WHILE THE LP ROTOR (ROTOR DRIVING THE LOAD) CAN CHANGE ITS NOMINAL SPEED (100% = 4.670 rpm) IN THE RANGE OF 50% (2340 rpm) TO 105% (4900 rpm)
Two Shafts G.E. G.T. Schematic COMBUSTOR(s)
VANES OF VARIABLE AREA NOZZLE GG STAGES
EXHAUST
PT STAGES
GAS
AIR INL ET LOAD FROM STARTING ENGINE
α
AXIA L TO AUXILIARY
COPRESSOR
GEAR BOX
GAS GENERATOR (GG)
POWER TURBINE (PT)
Gas Generator (GG) turbine drives axial compressor and turbine auxiliary by means of gearbox. Power Turbine (PT) drives the load, usually a centrifugal compressor or a pump, rarely an electric generator. PT e GG works at different speed. GG speed is constant during normal operation. PT speed can change in the range 50-105% of its rated speed during operation. The PT first nozzle is composed of variable vanes. In this way, by varying the angle α of the vanes, it’s possible to manage the power sharing between GG and PT by the speed control of the two rotors.
Speed/Load control in Two shafts G.E. HD GT IN THE G.E. H.D. TWO SHAFT GAS TURBINES, AS THE MS 5002, IN ORDER TO CONTROL THE SPEED OF HP AND LP ROTOR, A SECOND STAGE VARIABLE NOZZLE SYSTEM IS USED
G.E. HD Two Shafts GT: 2nd st.Variable Nozzles
Opened Variable Nozzle : Lowest Pressure Drop on the nozzle, i.e. HP Turbine lowest back pressure
G.E. HD Two Shafts GT: 2nd st.Variable Nozzles
Closed Variable Nozzle : Highest Pressure Drop on the nozzle, i.e. HP Turbine maximum back pressure
Two Shafts Gas Tubines for MD MS 1002 (*) PGT5/2 GE 5/2 (**)
(*) Out of p rodu ctio n, Upgrade are available (**) New m odel (***)
PGT 10/2 GE 10/2 MS 3002 (*) MS 5002
some GE Single Shaft Gas Turbin e can be used for MD applications. in special process as LNG, Methanol, etc
MS 6001, MS 7001, MS 9001
HEAVY DUTY Two Shafts G.E. Gas Turbine Production Range
Heavy Duty G.T. G.E. Supply Chain Greenville ( U.S.A.)
Firenze ( I ) Machine
GE5 GE10 FR5
GT MW 5.5
11
Machine
7E
Belfort ( F )
GT MW
Machine
85
6FA
7FA
172
9E
7H
400 (CC)
9FA
9FA
255
6B
9H
500 (CC)
GT MW 70 123
255
30 42.2
Nuovo Pignone
HEAVY DUTY GAS TURBINES COMPONENTS DESCRIPTION AND MAIN FEATURES
Inlet Section Gas Turbine
Inlet casing: directs the flow of outside air from the air inlet equipment into compressor blading Variable Inlet Guide Vane assembly N°1 bearing assembly Thrust bearings, active and inactive Low pressure air seals
Gas Turbine Axial Compressor
HD GT Axial Compressor Operation COMPRESSOR is the part of the engine where air is compressed
Compressor Discharge: (1) 30% is used for primary air (combustion air) (2) 5% is used to operation of gas turbine accessories:
-bleed air and seal air -gas turbine start and motor air -gas turbine anti-icing (3) Remainder is used as secondary air to: - cool combustion gases - Provide film cooling of the gas generator turbine
HD GT Axial Compressor Operation
HD GT Axial Compressor Design AIR Journal BEARING IGV
DISCS
TENSION RODS
Airfoils with large thicknesses Rotor stage discs linked by thick tension rods. Sliding Journal bearings Compressor Variable Inlet Guide vanes (IGV) (to control the air flow)
HD GT Axial Compressor Design
HD GT Axial Compressor Design
HD GT Axial Compressor Design
Random blades are selected for an automated check for the curvature, thickness, width and so farth.
HD GT Axial Compressor Assembly
Compressor Wheels: Rotor blades are inserted into these slot and held in axial position by spacer pieces, which are in turn staked at each end of slot
HD GT Combustion Chamber(s) Operation COMBUSTOR(s) is the part of the engine where air is mixed with fuel and burned with a portion of the compressor air
The combustion casing allows compressor discharge air to be directed through the flow sleeve and ultimately into the combustion liner
30%
30% 40%
HD GT Combustion Chamber Design COVER
SPARKLING PLUG
LINER
COMBUSTION CHAMB ER WRAPPER
GAS FUEL
LIQUID FUEL
REACTION ZONE
DILUITION ZONE
BURNER
E X H A U S T G A S
COMBUSTION AIR PORT
SLOTS OR HOLES FOR THE LINER COOLING AIR
AIR FROM THE AXIAL COMPRESSOR
GAS CONVEYOR “ TRANSITION PIECE”
- The air flow through the combustion chamber has three functions: oxidize fuel, cool the metal parts, condition the extremely hot combustion products to the desired turbine inlet temperature. - The air enters the combustion chamber and flows forward, entering the liner through holes and louvers in the liner wall. - A portion of the air reaches the head end of C.C. and enters the liner through the cap where the axial swirler creates a vortex.
NOx reduction for Heavy Duty Gas Turbines DRY Systems
WET Systems
1)
This system consists of the injection of atomized steam in the combustion chamber to decrease flame temperature and so NOx.
•
Easy to install
•
Requires Steam
•
Increases maintenance
2)
Water Injection * This system
DLN 1: Dry Low NOx .
Steam Injection*
consists of the injection of atomized water in the combustion chamber to decrease flame temperature and so NOx. DLN 2: Dry Low NOx .
•
Easy to install
•
Requires water
•
Increases maintenance
* Appliable for all GE HD GT
HD GT Turbine Section TURBINE is the part of the engine where the hot gases flowing fr om the combust or produce the mechanical power
The turbine can consist of several stages. Each stage is comprised of stationary row of nozzles where the high energy gases are increased in velocity and directed toward a rotating row of buckets, or airfoils, attached to the turbine shaft. As the gas flows through the turbine rotating shaft, the gas kinetic energy is converted into horsepower.
HD GT Turbine Section Operation
HD GT Turbine Section Design Rotor blades (“Buckets”) and stator nozzles with large thickness, with high corrosion and erosion resistance. They can accept also heavy fuel oil (residual treated oil), but with more frequent maintenance intervals.
ROTATION AXIS
HD GT Turbine Sec. Manufacture & Assembly …after the casting process, machining and grinding is done to the dovetail and to the sealing wings….
HD GT Turb.Sec. Blades Manuf. & Assembly …the bucket is then given a first and second coating…
…the last step before shipping is to give to each bucket a weight and a serial number.
HD GT Turbine Section: Nozzles Design In the turbine there are stationary nozzles which direct the high-velocity flow of the expanded hot combustion gas against the turbine buckets causing the turbine rotor to rotate.
HD GT Turbine Section: Nozzles Design
HD GT Turbine Section : Seals Design Unlike the compressor blading, the turbine bucket tips do not run directly against an integral machined surface of the casing but against annular curved segments called turbine shrouds.
HD GT Exhaust Section
Exhaust casing: the frame consist of an outer cylinder and an inner cylinder interconnected by radial struts. directs the flow of hot gas coming from the turbine section into the exhaust duct Turing Vanes are installed to reduce hot gas path turbolence / losses
HD Gas Turbine Bearings The gas turbine unit contains two/three or four main journal bearings, [depending on if the unit is single or two shafts type] used to support the gas turbine rotor. The unit also includes thrust bearings to maintain the rotor-to-stator axial position and to support the thrust loads developed on the rotor. These bearings and seals are incorporated in two, three or four housing, depending on the bearing number.
The GT bearings are pressure-lubricated by a fluid (oil) supplied from the lubricating system. The fluid flows through branch lines to an inlet port provided in each bearing housing.
HD Gas Turbine Journal Bearings Type:
Elliptical
HD Gas Turbine Thrust Bearings
Type:
Load (Equalizing) Unloaded (Non-Equalizing)
Gas Turbine:
Thrust Loads on Bearings (Example for a single shaft G.T. only)
Start-up and Shutdown Thrust is given by the prevalent action of the compressor load since in the turbine there is no gas expansion (turbine load gradualy increases starting from flame-on). In the same way, turbine reduces its thrust following the power reduction, till the flame out, during shut-down.
Load on Inactive Thrust Bearing
Normal Operation Thrust given by the action of the turbine becomes prevalent, respect to that one of the compressor, starting from flame-on and rising with the turbine load increasing (turbine power is about 200% of compressor power).
Load on
Active Thrust Beari ng
Thrust action direction, on the G.T. Bearing, changes during starting and loading sequence due to th e increased load on the tur bine. It happens, therefore, in the opposite sequence
G.T PERFORMANCES: Influence Factors EXTERNAL FACTORS EXTERNAL FACTORS • AMBIENT TEMPERATURE • AMBIENT PRESSURE • RELATIVE HUMIDITY • GAS FUEL PROPERTIES
INTERNAL FACTORS • PRESSURE DROP IN THE INTAKE SYSTEM • BACKPRESSURE IN THE EXHAUST SYSTEM • AXIAL COMPRESSOR CLEA NLINESS
Effects of Amb. Temper. on P, HR, AF/EF
T
S
Press. ratio If Tamb
Air Flow
⇓ ⇓
Power Output ⇓
Exh. Temp.
⇑
Heat rate
⇑
Effects of Amb. Temp. on Exh. Temp
Effects of Amb. Temp. (Part Load with Modulat. IGV)
Exhaust Temperature vs. Output Percent: VIGV Control Mode
Exhaust Flow vs. Output Percent: VIGV Control Mode
Effects of Ambient Pressure
T
S
If p amb
Pr. ratio
⇔
Air Flow
⇓
Power Output ⇓
Exh.Temp.
⇔
Heat rate
⇔
Effects of Ambient Humidity
T
S
If rH
Mass flow
⇓
Heat Rate
⇑
Power Output
⇓
G.T PERFORMANCES: Influence Factors INTERNAL FACTORS EXTERNAL FACTORS • AMBIENT TEMPERATURE • AMBIENT PRESSURE • RELATIVE HUMIDITY • GAS FUEL PROPERTIES
INTERNAL FACTORS • PRESSURE DROP IN THE INTAKE SYSTEM • BACKPRESSURE IN THE EXHAUST SYSTEM • AXIAL COMPRESSOR CLEANLINESS
Pressure drops effects on air intake system
INTAKE SYSTEM Pressure drop in the intake system is caused by the friction of air flow through the silencers, and by the change in direction of the air path along the intake ducting. Pressure drop causes loss of power (similar to the altitude effect) and the increase of specific fuel consumption (Heat Rate).
Pressure drops effects on Air Intake system
T
p 1'
S
p 1' = p 1 − ∆p ∆p = pressure
Pr. Ratio ∆p = pressure
drop
⇑
Mass flow
⇔ ⇓
Power Output ⇓
Exh. temp.
⇑
Heat rate
⇑
drop
Pressure drops effects on Exhaust system Backpressure in the exhaust system comes from the same mechanism of intake pressure drop, with the addition of the pressure drop due to the boiler, in case of a combined cycle. The increased back pressure reduces the expansion rate and the relevant amount of energy given by the turbine section. As for the intake losses, this causes loss of power and increase of specific fuel consumption (Heat Rate).
Backpressure effects on Exhaust system
T
p 4'
S
p 4' = p 4 + ∆p ∆p = pressure
Pr. ratio ∆p = pressure
drop
⇑
Mass flow
⇔ ⇔
Power Output ⇓
Exh. temp.
⇑
Heat rate
⇑
drop
G.T PERFORMANCES: Influence Factors COMPRESSOR CLEANING CONDITIONS
Performance Calculation Exhample ISO CONDITIONS (MS7001) Temperature (°C) Pressure* (mbar abs) Outpu t pow er*** (ISO kW) Heat Rate ***(kj/kWh) Turbine speed (100% RPM)
SITE CONDITIONS 15 1013 85400 10990 3600
Pressure (mbar abs) Temperature (°C) Inlet system ∆p (mm H2O) Exhaust system ∆p (mm H2O)
989 30 100 100
CORRECTION FACTORS
** FromTemperature Temperature correction correctioncurve curve **From *** Fromperf. perf.curves curvesdesign designdata dataand andnotes notes ***From
Fpressure = 989/1013 = 0.977 FkW- temperature ** 0,90 FkWInlet system ∆p *** = (100-1,7)/100 = 0,983 FkWExh system ∆p *** = (100-0,6)/100 = 0,994 FHR- temperature ** 1,020 FHR- Inlet system ∆p *** = (100+0,45)/100 = 1,0045 FHR- exh system ∆p *** = (100+0,5)/100 = 1,005
Site Outp ut Power (kW)
= ISOkW x 0.977 x 0,90 x 0,983 x 0,994 = 85400 x 0,86 =
73444
Site Heat Rate (kj/kWh)
= Design HR x 1,020 x 1,0045 x 1,005 = 10990 x 1,029 =
11308
Site Heat consumpt ion (Kj/s) = Site Output Power x Sit e HR = 73444 x 11308 / 3600 = Site thermal effici ency
(%) = 3600/ Site Heat Rate = (3600/ 11308) x 100
=
230710 31,80
PERFORMANCE ENHANCEMENT METHODS
1) Cooling inlet air
Inlet Temperature
2) Steam and Water Injection
Increase mass flow
3) Peak Load
Fire Temperature
WARNING !!
Inlet Cooling
Inlet Cooling: Evaporative Cooler Schematic
Inlet Cooling : Application Field
Inlet Cooling : System Balancing Care
Evaporative Cooling Vs. Inlet Chilling