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Largest Air Cooled Condenser made by GEA
Energietechnik GmbH, Germany – 6 × 665 MW Matimba
Power Station, South Africa (1991)
ACC for 95 MW Combined cycle Power plant at
Tamilnadu Electricity Board, Perungulam
(Steam flow –
118.7 TPH)
In an Air Cooled Condenser, exhaust steam flows from
the steam turbine through large ducts to a steam
distribution manifold. This manifold is on the top of
the ACC plant feeding an array of fin tube heat
exchangers. While exhaust steam flows inside the core
tubes, cooling air is drawn through the fins by large
fans.
The air takes the heat from the exhaust steam, which
converts to condensate. The condensate is collected in
the condensate storage tank and transferred to storage
tank/Deaerator.
Various configurations of Fin tubes such as "KL" fin tubes, "LL" fin tubes, "G" fin tubes, Extruded fin tubes, Hot dip galvanized (A) tubes and rectangular tubes with round
edge having Aluminum fins (ALEX) are
supplied by GCT. The hot dip galvanized tubes and ALEX
tubes are the latest generation fin tubes.
The best operating characteristics have been achieved
with the condenser dephlegmator scheme (KD scheme)
Some 85% of all ACC supplied worldwide are equipped
with a combination of parallel flow (condenser) and
counter flow (dephlegmator) heat exchangers. The KD
scheme provides some great advantages like no blanks
zones (dead zones) within the heat transfer surface;
very high operating stability during all load
transients (turbine load fluctuation, bypass
operation, air temperature fluctuation); absolutely
safe even under extremely low temperatures (minus 50° C) and under low load conditions.
The heat transfer optimization of the fin tube has led
to an elliptical shape/rectangular shape with round
edge and to an enlargement of the cross section of the
core tube. The so called "A - tube", tube which has been in use since 1981 and the "Alex" tubes which has been predominantly used since 2000 represent current state-of-the-art Fin Tube design.
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