Öresundsverket / CHP Malmö
Factsheet for
The steam turbine
Just like a gas turbine, the steam turbine generates
electricity but it also generates heat. The steam turbine has
a power output of 160 MW, compared with the gas turbine’s
output of 293 MW.
Short facts
•The turbine, manufactured by Alstom, weighs just over 300 tons with all
its auxiliary equipment and consists of components from several different
countries such as Poland, Germany, France and Switzerland.
•The turbine rests on a three-meter thick concrete base with an area of 400
square meters. The base is itself supported by 11.5-meter-high concrete pillars.
This is all to help dampen vibrations.
•The shaft speed of the rotor is 3 000 revolutions per minute and the outer
edges of the turbine’s rotor blades reach a top speed of 2 000 km/hour.
•Öresundsverket utilizes energy produced directly from the combustion of gas
fuel and energy produced from steam pressure to produce electricity in gas
turbines and steam turbines. The electronic efficiency thus reaches a level in
excess of 58 percent, which can be compared with the levels of 40-45 percent
achieved by conventional coal-fired power stations.
•At full production levels for electricity and district heat, the energy in the fuel
is utilized at a level close to 90 percent – only ten percent remains unused.
•The temperature of the exhaust gases after catalytic cleaning is 71° Celsius
– the vast majority of the heat energy has been utilized.
This is how it works
The steam turbine is powered, as the name implies, with steam. The hot steam comes from the boiler
and powers the turbine that via the generator produces electricity. However, some of the steam can be
diverted and utilized to heat water for Malmö’s district heating network.
This is the step-by-step process:
•The hot exhaust gases (630° Celsius) that are
formed when the natural gas-fired gas turbine
produces electricity heat up water, under
pressure, in the large steam boiler to steam at
565° Celsius.
•This steam is then led to the turbine’s rotors,
which it powers with great force and generates
electricity via the generator. The electricity then
travels to the power grid and on to the consumer.
•The turbine consists of a high-pressure section,
a medium-pressure section and a low-pressure
section. Together, these three sections weigh 197
tons of which the rotor accounts for 85 tons.
•Steam at 565° Celsius under a pressure of 140 bar
(equivalent to the pressure at 1 400 meters below
sea level) is led into the high-pressure section.
There the steam expands as the pressure drops to
26 bar and the temperature drops to 330° Celsius,
thus operating the steam turbine’s rotor and
generating 35 MW of electricity.
•After passing through the high-pressure section,
the steam is reheated in the boiler and then
passes into the medium-pressure turbine where it
generates 43 MW of electricity.
•Some of the steam from the medium-pressure
turbine can be drawn off to heat water, via a heat
exchanger, for the district heating network in
Malmö.
•If no steam has been drawn off, that is to say
there has been no district heating production,
the low-pressure section generates 82 MW of
electricity. If the steam is utilized for district
heating, the amount of electricity generated
drops in proportion to the amount of steam used
for heat production.
•By pumping out almost two thousand liters of
water at 90° Celsius every second, the Öresundverket can keep large portions of Malmö warm
when the cold tightens its grip on the city.
Öresundsverket has the capacity to provide 40
percent of Malmö’s heating needs.
•The amount of heat produced is controlled by the
need for heat and that is, of course, at its greatest
in the winter. Öresundsverket can under normal
conditions produce anything between 25 and 250
MW of heat. However, if there are exceptional
demands for heat, the plant can produce up to
408 MW of heat through shutting down the steam
turbine.
•The steam turbine can generate 160 MW of
electricity with no heat production and 110 MW of
electricity whilst producing 250 MW of heat.
•This heat can be called a byproduct of the plant’s
electricity production – by exchanging 1 MW of
electricity for 5 MW of heat. Öresundverket thus
obtains a very high degree of efficiency. Waste
and emissions are minimal.
Cross-section of the steam turbine
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4
5
1
High-pressure steam turbine with 29 stages, meaning 29
rows of guide vanes and rotor blades. Weight 39 tons.
3
Transportation pipe for steam from the mediumpressure turbine to the low-pressure turbine.
2
Medium-pressure steam turbine with 21 stages.
Weight 56 tons.
4
Low-pressure turbine with six stages in each flow
direction. Weight 101 tons.
5
Generator. Air-cooled. Weight 202 tons.
For more information, contact
E.ON Värmekraft Sverige AB, T +46 40 25 50 00
eon.se/oresundsverket
2010.10
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