Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
TURNKEY CHP SOLUTIONS AND
OPERATIONAL EXPERIENCE WITH
COMBINED CYCLE POWER PLANTS
BASED ON SIEMENS’ INDUSTRIAL
GAS TURBINES
MARTIN SIMEN
SIEMENS AG, POWER GENERATION,
ERLANGEN, GERMANY
Abstract
Cogeneration of heat and power (CHP) is acknowledged to be one of the most efficient and
environmentally favorable ways of energy conversion in the power generation industry.
Cogeneration has thus found political support, as it promotes high yield from primary energy
sources and supports decentralized energy supply. On the other hand, it is up to the producers
of power generation equipment and solutions to come up with advanced concepts for both
components and plant designs, to help cogeneration play an important role in future energy
markets from an economic point of view. In this paper, after discussing these market
requirements in detail, typical plant engineering solutions and applications are presented.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
Introduction
For providers of power generation equipment and solutions such as Siemens, the quest for
access to new and growing markets has always been a main business driver. In this sense,
over the last years, Siemens Power Generation has extended its activities in the industrial
power plant market from ‘classical’ steam power plants to biomass power plants such as the
Siecoline® reference plant product, to special power plants such as Kalina cycle based
geothermal plants, to waste incineration power islands and last not least to ga turbine simple
cycle, simple cycle extension, combined cycle (CC or GUD®) and combined heat and power
(CHP) plants. Such a broad spectrum of activities requires careful scrutiny of underlying
external market opportunities and threats as well as internal capabilities.
In the following we take a special look at the CHP technology. From the perspective of an
equipment manufacturer and plant solution provider, we analyze the external environment as
well as available concepts and products regarding this technology. In this sense, we divided
this presentation into three sections, a view of the CHP market, a discussion of possible
solutions to meet these market requirements and a reflection of solutions implemented so far.
CHP Market
With the acquisition of the Alstom Industrial Turbine segment announced in August 2003,
market accessibility in industrial power generation has substantially improved for Siemens
Power Generation.
September 23-25, 2003 Power Generation
Product Range of Industrial Gas Turbines
4 7 8 1317
25 29
43
67
010
2030
4050
6070
GT
outp
ut in
MW
Typhoon
Tornado
Tempes
t
Cyclone
GT35C
GT10B
GT10C
GTX100
V64.3A
Fig. 1, Product Range of Industrial Gas Turbines
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
As shown in Fig. 1, Siemens can now offer gas turbine products ranging from 3 to 70 MW.
Previously only the upper range of the market could be accessed with the V64.3A as an in-
house product, whereas for smaller power demands plant solutions depended on non-Siemens
gas turbine supply. The market potential over the next five years for industrial power
generation in the 3 to 70 MW range is shown in Fig.2.. The average yearly demand according
to Siemens’ projections is strongest in the 35 to 50 MW range with approximately 6 GW. The
3 to 14 MW and 15 to 34 MW market is of approximately the same size at about 2.5 GW
annually. The market in the upper power range of 51 to 70 MW is smallest at about 700 MW
annually, which underlines the significance for Siemens to extend its product portfolio to
lower power ranges. An analysis of the regional split of the 15 to 70 MW market shows the
Americas with about 40% and Asia/Australia with about 25% as core regions market share
followed by Europe and Middle East/Africa.
September 23-25, 2003 Power Generation
Market Volume in Industrial Power Generation
Source: Siemens
Total Power Generation Market in MW (Average 03-07)
Industry and Oil&Gas
2400
24006000
700
3-14 MW15-34 MW35-50 MW51-70 MW
41%
26%
21%
12%
AmericasAsia/AustraliaEuropeMiddle East/Africa
Regional Markets for GTs 15-70 MW (Average 03-07)
Industry and Oil&Gas
Fig. 2, Market Volume in Industrial Power Generation
A yearly breakdown of market projections in the 3 to 70 MW power range is presented in
Fig. 3. For clarity, the oil and gas power generation market due to its product specific market
mechanism is excluded in this analysis. The yearly projections show that after the market
breakdown in 2002 to about 25% of the 2000 level, recovery is anticipated after 2004 to
reach a relatively stable level of about 10GW annually.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
For an analysis of the qualitative drivers behind these quantitative projections, it is helpful to
distinguish between the short term, current situation and the long term trend, in order to cover
the strong dynamics observed in the market.
Analyzing the current situation in world regions, a leading influence is the overall market
downturn in North America which also affected industrial power generation. In Europe,
market liberalization along with changing legislation has led to uncertain economics for
investors, currently hindering growth especially in combined heat and power (CHP)
applications. The Latin American market is currently affected by overall economic slow
down and stagnant power market reforms. South East Asia shows signs of economic recovery
and increasing power demand, however still combined with relatively high reserve margins.
The Middle East and Africa represents an emerging market for CHP solutions especially for
small scale gas based power generation in oil and gas producing countries.
September 23-25, 2003 Power Generation
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Tota
l GT-
Ord
er V
olum
e in
MW
MW/a
Source: Siemens
Industrial Power Generation excl. Oil&Gas (GT 3-70 MW)
Market Development in Industrial Power Generation
Fig. 3, Market Development in Industrial Power Generation
Overall, the current situation in combined heat and power (CHP) generation can be
characterized by market uncertainty. This can be linked to two main factors, uncertain effects
of legislation and uncertain economics. For example in Europe, liberalization of the
electricity and gas market has led to lower electricity prices and fluctuating, relatively high
gas prices. In addition, quite contrary to the trend in America and Asia, deregulation in
Europe continues, with all non-household consumers free to choose power supply by 2004.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
This will lead to a separation of transmission & distribution from production & supply as
well as open access for consumers and producers to the power network, based on transparent
tariffs. In this unstable market environment, major power generation investments are
currently put on hold.
On the contrary, long term perspectives in the CHP market are favorable. Besides the long
term growing electricity demand due to population increase and economic growth, especially
the quest towards highly efficient power and heat generation and upcoming stringent
emissions regulations will lead to higher growth rates in CHP solutions. Decentralization of
power and heat supply especially favors solutions based on small industrial gas turbines.
Without a technology shift, it is expected that worldwide power generation related CO2
emissions would rise by 60% from 1997 to 2020. In consequence, for example in Europe, the
EU commission has defined a “common strategy for CHP” aiming at doubling the
contribution of CHP solutions from 9% to 18% by 2010. Environmental legislation will be a
strong driver for CHP, however it has to be monitored closely, as regulations such as
investment incentives are still country specific and subject to frequent change.
A look at the customer base in the CHP market reveals a major difference to large scale
power generation. Instead of a confined number of utilities or power producers, with power
generation as core business and competence, the CHP customer base is fragmented within a
wide variety of industries. It can range from refineries, chemicals, pulp & paper, cement,
textiles to pharmaceuticals, ceramics, food processing, timber manufacturers, breweries,
leisure parks to hospitals, universities, government offices, airports, community buildings
etc.. This variety presents a special challenge for sales activities as most customer relations
are transitory and local. On the other hand, CHP customers have the following requirements
in common:
1. Low Capital Cost
Power and heat generation is either considered a ‘no frills’ necessity to support the actual
core industrial process as e.g. for refineries, or capital funds are strictly limited as e.g. for
small scale industries in private ownership as. e.g. paper mills .
2. Low Life Cycle Cost
High efficiency and thus cost savings are a prime mover to invest in CHP solutions. This
gives gas turbine based solutions a competitive advantage over conventionally fired boilers.
3. High Reliability/Availability
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
In general industrial processes such as refineries require continuous operation. Hence,
customers for example may prefer redundant, small scale, easy to maintain gas turbines over
a single, large turbine for power generation.
4. Short Delivery Time
Frequently a gas turbine driven CHP plant is installed replacing an aged, inefficient, existing
boiler plant. To keep down-time of the industrial process to a minimum, CHP plant concepts
need to be designed for rapid installation. This favors modularized, container packaged
solutions.
5. Customized Solutions
Power and heat demand as well as layout requirements are generally site specific and within
narrow design margins. Hence, fully standardized plant solutions in general cannot be
implemented. However, a plant concept with standardized core components individually
adapted and arranged to meet site specific needs can be successfully established.
CHP Solutions
Customization can indeed be observed especially in CHP plants. A look at the installed base
can give the impression that “each plant is different”. However, the seemingly infinite variety
of heat and power combinations can indeed be classified into a limited number of principal,
underlying, thermodynamic cycle concepts, which fundamentally determine plant design
configuration. Standardization especially of gas turbines further reduces variety. Gas
turbines, other than steam turbines, are pre-designed to a fixed performance rating. Siemens’
industrial gas turbines now range from 4.35 MW electrical output for the Typhoon engine to
67.5 MW for the V64.3A engine in distinct intervals. Main conceptual classifications are
discussed in the following based on a comparative case study.
1. Simple Cycle
A benchmark for CHP cycle concepts is to compare efficiency against cycles for power
generation only. Selecting the Siemens GTX100 gas turbine with a net electrical power
output rating of 44.2MW for simple cycle base load operation on natural gas fuel, net
electrical and total cycle efficiency is at 36.4%. As parameters, ISO conditions with 15°C
ambient temperature, 60% relative humidity, sea level altitude, inlet and outlet losses of
5mbar have been assumed.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
2. Combined Cycle
In combined GTX 100 gas and steam turbine cycle operation, net power output increases to
63.8 MW and net electrical, total cycle efficiency for power generation reaches 52.7%
applying a dual pressure heat recovery steam generator. As water-steam cycle parameters,
15°C condenser and makeup water, 0.045 bar condenser pressure 0.045bar, 5K economizer
approach and 25K superheater terminal temperature difference, 10K pinch point and 1% heat
losses have been assumed.
3. CHP for Cogeneration
As a first comparison with CHP concepts, Fig. 4 shows results under the same conditions for
the least complex CHP cycle, a gas turbine with the exhaust gas used to produce process heat
in a single pressure heat recovery steam generator.
September 23-25, 2003
100 % fuel
1-pressure HRSG
Gas Turbine
CHP for Cogeneration(GTX100)
12 % losses
35.9 % electricity
52.2 % process heat
Pgt 43.82 MWPst 0 MWPaux 0.23 MWPnet 43.59 MWHeat duty 63.4 MJ/sQfired 121.4 MJ/s
Alfa 0.69 ---Net electrical efficiency 35.9 %Net total efficiency 88.1 %
Fig. 4, CHP for Cogeneration
With a gross electrical output Pgt of 43.82MW of the GTX100, for the cogeneration case no
steam turbine power output Pst and an auxiliary power consumption Paux of 0.23MW, a
combined net electrical output Pnet of 43.59MW is achieved. From the available 121.4 MJ/s
fuel heat (Qfired), 52.2% are converted into process heat (Heat duty), 35.9% into electricity
and 12% losses remain. This yields a power to heat ratio or cogeneration index Alfa of 0.69.
Net total efficiency, also termed fuel utilization, i.e. the percentage of fuel heat converted into
electrical and thermal output, has increased to 88.1% compared to 52.7% in combined cycle
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
power generation. Relatively low investment cost, simple technology but still high efficiency
make this so called cogeneration cycle the preferred solution for smaller size industries.
4. CHP for District Heating
A second CHP concept, frequently applied with inner city power plants, is presented in Fig.
5. Heat is transferred to the district heating cycle at 78°C, i.e. at relatively low temperatures
compared to industrial process applications. The steam turbine is of backpressure type and a
dual pressure heat recovery steam generator is applied. With the added power output of the
steam turbine, compared to the conventional cogeneration cycle, electrical efficiency is
increased to 47.2% and net total efficiency to 89.3%. Conversely, heat output is reduced to
42.1%, which yields power to heat ratio to 1.12.
September 23-25, 2003
100 % fuel
Gas Turbine
ST (district heating)
90 deg C
60 deg C
2-pressure HRSG
CHP for District Heating (GTX100)
510 deg C
78 deg C
78 deg C
11 % losses
35.9 % electricity
11.3 % electricity 42.1 %
heat
Pgt 43.70 MWPst 14.18 MWPaux 0.62 MWPnet 57.26 MWHeat duty 51.1 MJ/sQfired 121.4 MJ/s
Alfa 1.12 ---Net electrical efficiency 47.2 %Net total efficiency 89.3 %
Fig. 5, CHP for District Heating
5. CHP for low Process Steam Demand
CHP solutions for relatively low process steam demands are based on the power generation
combined cycle. The same main components, gas turbine, heat recovery steam generator,
steam turbine and condenser are applied, while the process steam is extracted from the steam
turbine at the desired temperature and pressure conditions. Fig. 6 gives a typical example.
Just 21% of the available fuel heat input is converted into process heat, while 44% is
converted into power resulting in the high power to heat ratio of 2.09. The reduced power
output of the steam turbine due to steam extraction yields 44% electrical efficiency compared
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
to 52.7% of a power generation only combined cycle. However, total cycle efficiency is at
65% significantly higher than for power only cycles. CHP solutions based on extraction
steam turbines are also selected to meet specific, high temperature and pressure process steam
requirements.
September 23-25, 2003 Power Generation
CHP for low process steam demand
steam turbine
21%
condenser
processsteam
100% Brennstoff33%
20%
11%
HRSG
15%
Fig. 6, CHP for low process steam demand
6. CHP for high Process Steam Demand
For relatively high process steam and low power demands i.e. low power to heat ratios,
conventional, fired boiler power plants have been built in the past. However plant efficiency
can be significantly increased, if part of the fuel is used to produce power with a high
efficiency gas turbine, while its exhaust gas is used to produce additional steam in the boiler.
Frequently, retrofit solutions by adding a small gas turbine to an existing large existing boiler
facility are implemented. A typical example for high steam demand is presented in Fig. 7. As
62% of the fuel heat input is converted into process heat at a typical steam temperature of
275°C, the power to heat ratio is just 0.37 and electrical efficiency just 23%. However total
CHP cycle efficiency is again very high at 85%, up to 10% higher than for conventional
boiler power plants.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
September 23-25, 2003 Power Generation
CHP for high process steam demand
15%
50 C
275 C process steam 62%
11%
gas turbine
36% fuel
12%
boiler
64% fuelo
o
520 Co
steam turbine
Fig. 7, CHP for high process steam demand
Available CHP solutions for a given gas turbine with unfired steam generators can be
summarized in a single diagram of electrical versus thermal output. For the GTX 100 turbine,
Fig. 8 shows, how electrical output drops with increasing process heat for CHP solutions
without (case 1 and 2) and with steam turbine (case 3 to 5).
September 23-25, 2003 Power Generation
CHP output(GTX100)
40000
45000
50000
55000
60000
65000
0 10000 20000 30000 40000 50000 60000 70000
Process heat (kJ/s)
Elec
tric
outp
ut (k
We)
33
38
43
48
53
Elec
tric
effic
ienc
y (%
)
40% 50% 60% 70% 80%
0.8 bara
2 bara
5 bara
10 bara
25% Extraction
50% Extraction
75% Extraction
Back Pressure
Cogeneration (no steam turbine) 0.8 bara
Totalefficiency90%
process heat (kJ/s)
Net
ele
ctric
effi
cien
cy (%
)
Net
ele
ctric
out
put (
kWe)
Net total efficiency (%)
Co-generation (no steam turbine)1 2
3
4
Condensing ST, with extraction Backpressure ST
Fig. 8, CHP output (GTX100)
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
Also, as a general rule, electrical efficiency drops with increasing process heat, while total
cycle efficiency increases. In addition, the diagram shows the decrease in power output for
increasing steam extraction or pressure levels. As stated initially, the large variety of possible
heat and power combinations becomes obvious. However the diagram also confirms the
statement that a limited number of principal CHP solutions (cases 1 to 5) can cover this
variety of requirements.
This conclusion is good news for plant designers trying to standardize plant layouts in an
effort to meet customer requirements to reduce cost, delivery time and increase reliability.
One successful example is the now industry wide spread use of standardized pre-packaged
modules containing the pre-tested gas turbine plus its auxiliary systems. Examples within the
Siemens product range are shown in Fig. 9 and 10.
September 23-25, 2003 Power Generation
Cyclone Modular Package
Fig. 9, Cyclone Modular Package
Depending on machine size, the auxiliary systems are either fully integrated as sub-modules
on the base frame as for the Cyclone turbine, or placed next to the turbine frame within the
gas turbine enclosure, as for the GTX100 turbine. For the V64.3A, the largest Siemens
industrial gas turbine, turbine frame size is already 12x5.5x6 meters. Therefore all auxiliaries
are placed in a single lift auxiliaries module (SLAM), which is connected to the turbine via
the single lift intermediate module (SLIM) containing interconnecting piping. The packaged
solution significantly reduces plant footprint and site installation time, while the fully
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
instrumented, wired and pre-tested turbine systems improve product quality. Finally the
standardized package design reduces cost and thus price. So overall, packaging provides a
‘win-win situation’ for both customer and manufacturer.
September 23-25, 2003 Power Generation
GTX100
V64.3A
Gas turbine Packaging
Fig. 10, Gas turbine packaging
Starting standardization at the plant core, the gas turbine, seems natural. This concept is the
base of the the Siemens reference power plant (RPP) design approach shown in Fig. 11,.
Standardization is considered to start from the insight out, while customization starts from the
outside in. Specifically, RPP design starts with the gas turbine and auxiliaries, the so called
Econopac, continues on to the power island, which additionally includes steam generator,
steam turbine, condenser and generators, furthermore includes the power block, which also
includes water steam cycle, electrical equipment, cooling water system, to finally comprise
additional turnkey plant components like fuel, water supply and treatment systems as well as
civil scope such as buildings and foundations. To optimize the balance between
standardization and adaptability, RPP design depth decreases from the inside out, while the
number of design options increases.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
September 23-25, 2003 Power Generation
HV Switch-
gear
Water Pretreatment
BuildingFacilities
Fuel OilStorage
Site Gas Preheating
FuelTransfer
CivilCooling
Tower
WaterSupply
WaterTreatment
RPP Design Approach
Electrical
W/S-Cycle
Machine House Arrangement
I&CGT
GeneratorST
Condenser
HRSG
Customizationstarts from outside to inside ...Customizationstarts from outside to inside ...
... Standardization
starts from inside to outside
... Standardization
starts from inside to outside
Fig. 11, Reference Power Plant (RPP) design approach
A typical example of power island RPP design is shown in Fig. 12. The GUD® 1S.64.3A,
rated at 99.8 MW net power output and 52.2% net electrical efficiency, is a single shaft
combined cycle power plant. The power island comprises the core power train with one
V64.3A gas turbine including gear box, one air cooled generator, a synchronous clutch and a
single casing steam turbine with axial exhaust to the condenser. The gear ratio between the
gas turbine and the generator is 5400/3000 or 5400/3600 rpm according to 50 or 60 Hz
application.
The dual pressure non reheat HRSG operates at 70 bar high pressure and 5 bar low pressure.
For CHP applications, steam extraction for industrial processes or district heating purposes is
possible over a wide range of pressure and temperature levels. A 100% steam bypass system
allows high operating flexibility and even open cycle operation w/o exhaust gas bypass.
The single shaft GUD® power train with the gas turbine and the steam turbine driving one
common generator has various advantages of the alternative multi shaft arrangement:
1. Enhanced simplicity and flexibility,
2. Increased efficiency and output,
3. Reduced lead times,
4. Lower specific investment cost,
5. Improved reliability and availability,
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
6. Simplified operation & maintenance.
Overall, the above benefits result in lower life cycle cost.
September 23-25, 2003 Power Generation
1 Gas turbine2 Air intake duct3 HET gear box4 Generator with cooler5 SSS clutch6 Steam turbine7 Condenser8 Closed cooling water pump
9 Closed cooling water heat exchanger10 Vacuum pump11 Main cooling water pipes12 Main condensate pumps13 Generator bus duct14 Lube oil tank and coolers15 Space allocated for maintenance16 Filter house17 Generator circuit breaker18 Unit transformer19 Power control center20 Unit control room21 Gas turbine auxiliaries container22 Heat recovery steam generator
48 m
20 m
21
22 1
2
14
17
18
19
15
5 6
10
20
37
89
11
1213
16
4
1SV64.3A Single Shaft Power Island
Fig. 12, 1SV64.3A Single Shaft Power Island
A unique feature of single shaft design is operating flexibility. Due to the use of a SSS clutch
between the generator and the steam turbine, the gas turbine can be started individually
without any restriction by the actual condition (hot, warm or cold) of the steam turbine and
the cooling system. After steam of appropriate quality is available from the HRSG, the steam
bypass valves will be closed and the steam turbine be started up.
The SSS clutch automatically engages when the steam turbine is accelerated to the generator
speed. Then the steam turbine is loaded. Full load can thus be achieved in less than 80 min
(120 min) at warm (cold) condition.
The steam turbine and gas turbine cycles can be decoupled not only during start-up but also
during operation via the synchronous clutch. The GT can then be operated independently
from the ST. The steam is dumped to the condenser via the bypass station. For shut-down the
GT exhaust gas and steam temperature are limited to allowable temperature transients.
Therefore, the steam turbine is disconnected from the from the GT at full steam temperature
to allow shortest possible shut-down time.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
The short start-up, shut down, as well as the high loading/de-loading rates provide the
operator with great flexibility in timing the plant dispatch for intermediate load or plant
shifting requirements.
A typical example of a multi shaft arrangement is shown in Fig. 13. It is based on the GT10C
gas turbine, the latest product in the GT10 family introduced in 2000.
September 23-25, 2003 Power Generation
1xGTX10C multi shaft Reference Plant
Net electrical output 41.3 MWNet electrical efficiency 51.1%
Fig. 13, 1xGT10C-multi shaft Reference Plant
In combined cycle operation, the GT10C gas turbine is rated at 28.5 MW, while the steam
turbine generates an additional 13.2 MW and auxiliary loads consume 0.45MW, which brings
total net plant output to 41.3 MW and net efficiency to 51.1%. A reference multi shaft
configuration based on two GT10C gas turbines and one steam turbine yields a net total
output of 83.6MW and 51.8% efficiency.
The family of Siemens combined cycle power plant reference designs based on GT10B,
GT10C, GTX100 and V64.3A gas turbines covers a wide range of power outputs. The 1x1
configurations (one GT, one ST in single or multi shaft design) range from 36MW to
102MW, whereas the 2x1 multi shaft configurations cover a range from 73 to 201MW.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
CHP Experience
With the extended gas turbine product range from 4 to 67.5 MW, Siemens can offer broad
and long lasting experience in CHP projects.
In the 4 to 15MW gas turbine market, Siemens CHP projects date back as far as 1954 with
the Bank of England as a customer in the United Kingdom. Meanwhile 458 units have been
installed by Siemens within this market segment for CHP applications. Within the presently
offered gas turbine range, the Tornado rated at 6.75 MW was the first to become involved in
CHP in 1981, when a food factory in the Netherlands needed heat and power to operate its
facilities. Consequently the Typhoon rated at 4.35 MW was introduced in 1989 to CHP for a
pulp & paper mill in the United Kingdom. This was followed by the Tempest turbine rated at
7.9 MW in 1996, when a ceramics and textiles plant in Turkey needed CHP. Finally the
Cyclone turbine was introduced to CHP in 2000.
Fig. 14 shows the lead Cyclone CHP site, the Bulwer Island refinery in Brisbane, Australia.
BP Refinery Bulwer Island was constructed by Amoco Australia in 1962, acquired by BP in
1984 and employs approximately 260 people. The refinery’s commercial products includes
diesel, jet fuel and fuel oil.
September 23-25, 2003 Power Generation
GT1 Package 22,051 HrsGT2 Package 22,166 Hrs
Bulwer Refinery: Cyclone Lead CHP Site
Fig. 14, Bulwer Island: Cyclone Lead CHP Site
In July 1998, Bulwer Island refinery launched the Queensland Clean Fuel Project to increase
Bulwer’s processing capacity from 73,000 to 88,000 barrels of crude oil a day and enable it to
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
produce environmentally friendly fuels with less than 50 parts per million of sulphur in its
diesel and petrol. The developer BIEP (Bulwer Island Energy Partnership) selected two
Cyclone gas turbine generating sets to provide power and heat for the cogeneration plant.
These are the world’s first operational Cyclone gas turbines and entered commercial service
in July 2000. To date 36 Cyclone gas turbines have been sold and more than 110.000
equivalent operating hours have been accumulated. Bulwer Island as the lead site has
accumulated over 22.000 hours. The cogeneration plant supplies 27 metric tons per hour of
steam or 55 MW of thermal energy and 32 MW of electricity to the refinery, with surplus
electricity exported to the Queensland grid. Prior to installing the cogeneration plant, the
refinery’s considerable energy needs were met by oil fired boilers for steam with all
electricity imported from the grid. The Cyclones operate on natural gas and incorporate a dry
low emissions combustion system to reduce NOx and CO levels to below 25ppmv. Provision
is also made for the injection of surplus steam into the turbine to provide power enhancement.
The cogen plant is Queensland’s cleanest and, at 75%, also the most efficient. It will help
reduce greenhouse gases in the State by 90,000 tonnes per year. An innovative CHP concept, implemented at the Papier und Kartonfabrik in Varel, north-
west Germany, is presented in Fig. 15.
September 23-25, 2003 Power Generation
Varel paper mill, Germany: Tempest CHP site
Fig. 15, Varel paper mill, Germany: Tempest CHP site
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
The paper mill manufactures quality cardboard and papers for corrugated board. It produces
350,000 tonnes of grey and brown board, laminated board, test liner and colour cover board.
The paper products are sold to France, Norway, Sweden and Austria. The paper mill uses
substantial amount of electricity and steam for production which are provided by its own on-
site cogeneration plant. The existing utility comprised of one conventional 60 ton steam
power unit feeding two steam turbines of 3 MW each and one System Hutter® combined gas
and steam unit generating 45 tonnes of steam and 10 MW of electrical power. The patented
combined cycle system developed by Friedrich Hutter GmbH Consulting Engineers was
commissioned in 1989 and has been operating for more than 120,000 hours at a reliability
rate of 99.5 %.
In view of further expansion of paper production and quality improvement, the paper mill
decided on a second combined cycle System HUTTER and retrofitted the existing 60 tonnes
radiation type boiler. The decision was based on a feasibility study, showing superior results
of internal rate of return comparing with all other technologies.
The new combined gas and steam cogeneration scheme consists of a Tempest gas turbine
generating set, a waste heat boiler and a steam turbine. The boiler is a radiation type boiler
uprated to 70 bars, 470 °C with a steam rate of 65 tons per hour and the steam turbine has a
power output of 8.8 MW. The upstream arranged Tempest gas turbine contributes to the
overall power output. The gas turbine’s exhaust gas has an oxygen content of 15% volume
and feeds into the main power burner of the radiation type boiler. The firing rate of the main
burner is 38 MW and the heat content of the gas turbine’s exhaust gas contributes one third of
the boiler’s input demand for generating superheated steam. This is the first Tempest gas
turbine sold in Germany and also represents the 50th Tempest to be sold worldwide.
With a fuel utilization of 93%, this CHP system allows Papier und Kartonfabrik to have a
continuous production process at highest efficiency and also contribute environmentally by
reducing CO2 emissions. The utility operates continuously, connected to the remote
monitoring system EDEN (Electronic Data Exchange Network) for diagnostics within a
Siemens service center. As of August 2003, the gas turbine has logged 1685 hours and 136
starts.
In the 15 to 50 MW gas turbine market, application of Siemens gas turbines in CHP date back
to 1984 with a GT10 gas turbine installed in a cogeneration plant at Runcorn, Great Britain.
Complete CHP plants have been delivered since 1991 based on the KA10 reference design.
Fig. 16 gives an overview, how installed plants are regionally distributed. With a focus on
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
Europe, projects with gas only or dual fuel supply have also been implemented in the Middle
East and Asia. As of today, plant design experience comprises 37 CHP or combined cycle
(CC) projects. Whereas the GT35, rated at 17 MW has once been selected for CHP projects,
the GT10/10B rated at 24.8 MW is the workhorse with 26 CHP plant applications. The
GT10C engine rated at 29.1MW has just recently been introduced to the market with 5 units
sold to date.
September 23-25, 2003 Power Generation
GT10 CHP/CCPP Worldwide References
Ängelholm 1xDHKarlskoga 1xDHLund 1xCGLinköping 1xDH
Den Bosch 1xCEHelmond 1xCEEerbeek 2xCEBorculo 2xCEBergen op Zoom 1xCETer Apelkanaal 1xBErica 2xDHKlazienaveen 2xDH
Lausanne 1xDH
Dessau 1xDHGera 2xDHRostock 3xDHPotsdam 2xDHNeubrandenburg 2xDHFrankfurt Oder 2xDHBonn 1xCG
Electrostal 1xCG
Maricogen 1xB
Soporcel 2xB
Borsodchem 1xCG
Titan, Pasir Gudang 2xCGTitan, Tanjung Langsat 1xC
Gaza 2xC
B: Backpressure STC: Condensing STCE: Extraction STCG: CogenerationDH: District Heating
Fig. 16, GT10 CHP/CCPP Worlwide References
Of special interest is the largest and most efficient Siemens unit in this market segment, the
GTX100 rated at 43 MW, which was first applied to CC power generation in 1998. As shown
in Fig. 17, to date 22 units have been sold with 11 units in CC and 10 units in CHP
applications. Approximately 50.000 operating hours have been accumulated.
The lead site with the first GTX100 installed is the Västhamn plant, located in Helsingborg, a
city of around 115.000 people in the south of Sweden. The owner, Öresundskraft, a
municipally-owned energy utility in Helsingborg, serves more than 1700 commercial
buildings and 5500 homes with electricity, district heating/cooling, supply of natural gas and
communication services within Helsingborg and also sells electricity within Sweden and
Denmark.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
September 23-25, 2003 Power Generation
GTX100 CHP/CCPP Worldwide References
Helsingborg 1xDH
Arjo Wiggins 1xCOGEmin Leydier 1xCOGCerestar 1xCOG
Gendorf 1xCOGHöchst 1xCOG Sandreuth 2xCOGWurzburg 1xCOG
Solvay 1xCOG
Michelin 1xCEBlackburn 1xCE
MMPA 1xSCRedding 1xCOGVernon 2xC
Moscow 4xDH
Riga 2xDH
B: Backpressure STC: Condensing STCE: Extraction STCG: CogenerationDH: District Heating
Fig. 17, GTX100 CHP/CCPP Worlwide References
The plant consisted originally of a 220 MW boiler supplying 78.5 kg/s of steam at 110 bar/
538C to a single-casing, axial-flow steam turbine, rated 64 MWe (electrical). The steam
turbine exhausted into two-stage district heating condensers supplying 132 MWt (thermal) to
the district-heating network. When the plant opened in 1983, it was fired by coal (main fuel)
and oil (backup fuel) to stabilize combustion at low loads. However, wood pellets have been
used increasingly in recent years, accounting for more than half the fuel used during the latest
years.
The key objectives of the extension project were, to
1. increase the output of the plant, primarily in electrical but also thermal output, minimizing
investment cost,
2. increase plant electrical and total efficiency,
3. significantly reduce emissions,
4. maintain availabiltiy and fuel flexibility of the existing plant.
The resulting optimum concept was to extend the plant with a dual fuel GTX100 gas turbine
and a heat recovery steam generator, while retrofitting the steam turbine for higher mass
flows.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
As a result, the extended retrofit CHP plant as presented in Fig. 18, had electrical output
almost doubled from 64 to 126 MW, whereas thermal output was merely increased from
132MWt to 186MWt. Electrical efficiency increased from 30 to 38.5% and total plant
efficiency for 90 to 96%. NOx emissions were signifcantly reduced from 800 to 300
ktons/year, and CO2 emissions for 350 to 200 ktons/year.
September 23-25, 2003 Power Generation
Västhamn plant: GTX100 CHP retrofit site
DH supply
DH return
MWe tot = 126MWth tot = 186Alfa = 0.67% el. efficiency = 38.5% tot. efficiency = 96
HelsingborgGTX 100
Fig. 18, Västhamn plant: GTX100 CHP retrofit site
Within the Siemens gas turbine product range, the 50-70MW market segment is covered by
the V64.3A gas turbine. In 1994, Siemens Power Generation (PG) launched the advanced
V64.3A based on a scale-down approach from the V84.3A/V94.3A. The goal was to reduce
the specific kW-price of the engine by improving the turbine output and implementing
design-to-cost measures based on the proven V64.3 design, while leaving as many
components as possible left unchanged. The gas turbine, rated at 67.5 MW gross electrical
output and 34.8% gross electrical efficiency, was especially designed for application in mid-
size CHP and combined-cycle (CC) plants, allowing base load as well as cycling duty (daily
start-stop) operation. It can be synchronized to both 50 and 60 Hz grids using a reduction
gearbox. Design and factory full load testing was completed in 1998. Meanwhile, as shown in
Fig. 19, with the first unit in operation in 1999, 13 V64.3A turbines have been sold to operate
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
in ten power plants for 50 and 60 Hz grids worldwide. It has logged over 150.000 operating
hours mainly in cogeneration, but also combined cycle applications.
September 23-25, 2003 Power Generation
V64.3A CHP/CCPP Worldwide References
CHP/CCPPCHP/CCPP
Norhtern IrelandBallylumford / 2002
GermanyAltbach HKW 2 / 1999Hannover Linden 3 / 2000Lausward GuD / 2000
Dominican RepublicSan Pedro de Macoris 1 / 2001San Pedro de Macoris 2 / 2001San Pedro de Macoris 3 / 2002
Czech RepublicBRNO Cervený Mlýn / 1999
CIS-RussiaTjumen / 2004
PolandRzeszow / 2003
ItalyTerni / 2000
GhanaEffasu 1 / 2000Efasu 2 / 2000
Fig. 19, V64.3A CHP/CCPP Worlwide References
The lead site for first CHP application of the V64.3A is the Altbach-Deizisau plant located in
Altbach, Germany. In 1993, Neckarwerke Elektrizitätswerke AG, Germany, ordered the first
commercial V64.3A gas turbine, a steam turbine and I&C equipment for implementation in a
new 420-MW cogeneration plant called HKW 2, replacing three 35-year-old steam turbine
units in the existing Altbach-Deizisau plant. As shown in Fig. 20, in the parallel-fired
combined cycle, steam for the 350 MW supercritical steam turbine is generated by a once-
through coal-fired boiler and a heat recovery steam generator. The V64.3A gas turbine
operating on natural gas, exhausts into the unfired HRSG, which is connected in parallel to
the steam cycle for supplementary steam generation in order to improve overall efficiency.
Both steam generators are of the Benson-type once-through design. The GT and the ST can
be operated independently, resulting in high flexibility. The gas turbine is operating in a
daily start-stop cycle with only few operating hours a day. The new plant was commissioned
in 1997 and in operation 1999.
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
September 23-25, 2003 Power Generation
Altbach-Deizisau Unit 2:V64.3A Parallel-powered CHP Plant
Maximum possible heat extraction 280 MW
G~
Station efficiency
G~
~ 90°C
Heat-recoverysteamgenerator
A1
A2 - A3
A5 - A7
A4
540°C59 bar25.3 kg/s
565°C560°C
CoalAir
GT
Air Fuel gas
64.8 MW
540°C239 bar247 kg/s District heat
(max. 280 MW)
347.1 MW
0.071 bar
Hybrid-coolingtower
Parallel-powered combined-cycle operation
Steam generator(alone)
Gas turbine(alone)
50
45
40
35
30
25
20
150 100 200 300 400
Net output in MW
Fig. 20, Altbach-Deizisau Unit 2: Parallel-powered CHP Plant
The largest V64.3A turnkey project built to date is the combined cycle facility San Pedro de
Macoris, located in the Dominican Republic. Siemens PG built the state-of-the-art 300 MW
CCPP San Pedro de Macorís power plant in the Dominican Republic for CESPM, a
consortium consisting of Cogentrix USA and CDC England. The project was executed on the
basis of a turnkey EPC contract, which became effective in April 2000 after financial close
and construction started in May 2000. The project site is located approximately 65 km east of
the capital city of Santo Domingo.
As shown in Fig. 21 the plant consists of three nominal 100-MW GUD® 1S.V64.3A blocks.
Each module is equipped with a V64.3A gas turbine, an air-cooled generator, a single-
casing/axial exhaust industrial-type steam turbine and gearbox aligned on a single shaft. A
duct-fired, dual-pressure, non-reheat HRSG converts the exhaust energy of the gas turbines to
live steam for the steam turbines. The condenser is cooled by a forced-draft, cell-type cooling
tower. The plant is operated exclusively on #2 fuel oil for the first few years. Due to the
choice of #2 fuel oil, water injection is necessary to reduce NOx emissions. Once natural gas
(LNG) becomes available on the island, the engines will be converted to dual-fuel operation.
Using a configuration with three identical blocks allows a reduction of redundancies for the
main pumps in the feed and condensate system. This consequently reduces capital costs and
maintenance efforts. Under the given ambient conditions with fuel oil and water injection, the
plant achieves an output of 3x 99.2 MW and 48.2% net efficiency
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
The first concrete was poured in late June 2000. Erection of the steel structure commenced in
October 2000. The first turbine building was finished in December 2000 and ready for the
start of electro-mechanical erection in January 2001. The first heavy load-transport for Unit
10 with gas turbine, gearbox, generator, steam turbine, condenser, lube oil tank, transformers
and three Power Control Centers (PCC) arrived at the site on January 11, 2001. After a
construction period of only 15 months, the first unit went into commissioning and was handed
over to the client on November 19, 2001. Unit 2 followed in December 2001 and Unit 3 in
January 2002, five weeks ahead of schedule. Cogentrix de La República Dominicana was
formed to operate and maintain the facility with a staff of 31 employees (two expatriates and
29 Dominicans).
September 23-25, 2003 Power Generation
San Pedro, Dominican Republic:3xV64.3A turnkey CCPP site
3 x 100 MW el, Single Shaft3 x V64.3A, ST Condensing 38 MWCommercial Operation 2001
3 x 100 MW el, Single Shaft3 x V64.3A, ST Condensing 38 MWCommercial Operation 2001
Fig. 21, San Pedro, Dominican Republic: 3xV64.3A turnkey CCPP site
Conclusion
Future outlook for CPH plant applications is positive. Despite current market uncertainties,
long-term demand for highly efficient, low emissions CHP solutions will grow. Customer
requirements for low capital and life cycle costs, high reliability, short delivery time, and site
customization can be met by available technologies. Optimized CHP concepts exist for a
wide variety of applications ranging from low cost cogeneration plants, highly efficient
district heating plants, steam extraction concepts tailored for industrial processes, to parallel
gas turbine and fired boiler plants for ultimate flexibility. Concepts for fuel utilization of
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Power-Gen Asia 2003 Ho Chi Minh City,Vietnam
around 90% and power to heat ratios between 0.3 and 2.1 have been presented. Plant power
outputs may vary from 4MW to 100MW based on single Siemens industrial gas turbines.
Reference power plant designs have been developed for single and multishaft applications,
optimizing standardization and design flexibility. To build up a sustainable and profitable
competitive advantage in the future, CHP plant providers will have to offer product based
rather than merely project specific plant solutions.
Acknowledgements
This paper would not have been possible without the contribution in particular of the
following individuals: Jan Wikner, Siemens Power Generation, Finspong, Sweden, Mike
Welch, Siemens Power Generation, Lincoln, UK, Geraldine Roy, Siemens Power Generation,
Lincoln UK, Rob Barnes, Siemens Power Generation, Lincoln, UK, Harald Dichtl, Siemens
Power Generation, Erlangen, Willibald Fischer, Siemens Power Generation, Erlangen, Klaus
Huettenhofer, Siemens Power Generation, Erlangen
References
- K. Huettenhofer/ A. Lezuo, Cogeneration Power Plant Concepts, VGB Kongress 2000
- J. Wikner, Conceptual review of different GT-cycles and their abilities concerning
electrical efficiency, total efficiency and power/heat ratio, Dresden 2002
- W. Fischer, Turnkey CCPP and CHP Solutions based on Siemens’ V64.3A Gas Turbine,
PowerGen Europe, 2003
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