90 MW Cogeneration
Power plant for Indian
Petrochemicals,
Gandhar
 46 MW
captive power plant for Gujarat Cements, Piparav |
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Turbine Details :
Gas Turbine Based Power Plants : Technology and Market Status
This Note provides an overview of the issues related to
the development and utilization of gas turbines (GT)
when used either in open cycle or combined cycle
(CC), and is divided into three major parts:
-
Natural gas fired plants.
- Non natural gas fired plants utilizing fuels such as
low Btu gases, ash forming fuels oils (e.g. crude
oils and heavy oils), naphtha, condensates or gases
from the iron and steel industry.
- Integrated gasification combined cycle (IGCC).
Technology and environmental performance, design,
costs and trends in market demand are discussed. The
paper indicates how ongoing research and development
trends can deliver further efficiency and performance
benefits.
Major points discussed in the Note
include :
-
Industrial gas turbines are a well established technology,
manufactured by major industrial groups in
Europe, Japan and North America whose performance
has benefited greatly from the large expenditures
over the last fifty years on the development
of aero jet engines. Ongoing development and near
term introduction of the most advanced products
will improve GT efficiency to about 40% in the case
of the largest GT units (250 MW to 350 MW). GTs,
in combination with waste heat recovery steam gen-
erators that supply steam to steam turbines thus
forming a combined cycle (CC) plant, are already
achieving efficiencies well over 50%, with these
projected to approach 60% within the next few
years with corresponding plant capacities being in
the range of 375 MW to 500 MW.
-
Using low cost salts such as Epsom salts as
inhibitors the GT components of combined cycle
plants can be successfully fired with contaminated
fuel oils of high sodium and vanadium content. Use
of such fuels demand less sophisticated gas turbine
technology with lower inlet temperatures and rigorous
monitoring so that formation of corrosive salts
and acids is entirely inhibited.
-
In some countries, deregulation followed by competition
has caused downward pressure on generator's
prices thus benefiting GT technology since power
from these units can be produced at very competitive
rates especially in the current environment of low oil
and gas prices. Tightening environmental standards
have also helped to increase market share of GTs
since their low specific emissions of SOx , NOx , particulates
and ash provide them with a comparative
advantage over other power generation technologies.
Their relatively low level of greenhouse gas
(GHG) emissions may also be noted.
-
GTs have the ability to handle a wide variety of
fuels of varying quality, including low calorific
value as well as contaminated fuels (the latter
requiring great care for their successful use). IGCC
that utilize refinery fuels and gasified coal is
expected to become a widespread commercially
proven technology. This is likely to occur first in
developed countries for refinery applications.
In the case of developing countries and
especially for coal based applications, commercial
competitiveness is still to be demonstrated. This
results partly from the fact that in developing countries
technical operating risks are perceived to be
greater with some consequences for commercialization
of the technology.
-
The cost and construction time of GT based plants
have been reduced in part because of design standardization
and automation as well as their modularity
i.e. plant construction and commissioning can
be staged in accord with the demands of the power
system.
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