An air cooled condenser (ACC) is a direct dry cooling system where steam is condensed inside air-cooled finned tubes. The cool ambient air flow outside the finned tubes is what removes heat and defines the functionality of an ACC. In thermal power plants (T), the steam from the turbine exhaust flows into the ACC where condensation occurs. Then the condensate returns to the boiler (B) in a closed loop. Since the steam coming from the turbine is at a low pressure, the ACC works at a pressure close to a vacuum, and non-condensable gases (G) are removed continuously by an air evacuation unit.
ACCs work well in water-scarce areas
Air cooled condensers are used for thermal power plants like combined cycle, concentrated solar, coal, biomass, and waste to energy. Since these kinds of power plants, which are equipped with ACCs, do not require a large volume of cooling water, the power plants can easily be built in a region where water may not be available, or where its use is restricted or expensive.
The Building blocks of an air cooled condenser
An air cooled condenser is made up of modules that are arranged in parallel rows. Each module contains a number of fin tube bundles. An axial flow forces the cooling air across the heat exchange area of the fin tubes.
The typical set-up for an ACC installation includes:
- the supporting structure
- the steam ducting from the steam turbine interface
- heat exchangers, finned tubes, fans, motors, gearboxes, and auxiliaries such as the condensate and drain pumps
- condensate and duct drain tanks,
- the air evacuation units
- related piping works and instrumentation
Got more questions about ACCs? Have a look at our Air Cooled Condensers! Or get in touch directly