Air cooled condensers triumphantly make their way to South Hedland

Getting two massive 408 tonne pieces of equipment from China to our South Hedland, Western Australia construction site is no easy task. It takes a detailed plan and months of preparation to put this large job into action.

TransAlta’s new 150 MW South Hedland natural gas combined-cycle power station, to be fully commissioned in 2017, will be equipped with two GEA air cooled condensers manufactured in China.

As TransAlta’s South Hedland site is located in a cyclone region, the project team did not want to take any delay risks with assembly of the air cooled condensers on site, so a decision was made to have the two air cooled condensers manufactured at GEA’s fabrication yard in China and have the fully assembled modules shipped to site. With a 20-day travel time on a large cargo ship to Port Hedland, the massive cooling towers then had to make their way to the South Hedland power station construction site, approximately 20 km away from the port.

“Since the towers are so large and heavy, we needed to close roadways and use specially designed tow and pull system to transport the towers to site,” says Jamie Hodel, South Hedland project manager.

Each condenser module is 38 meters (m) long, 12m wide and 15m high — not your average semi-truck load. Instead, each module was loaded on a specially designed trailer that is pulled by two tractors and pushed by another tractor. A 408 tonne unit also doesn’t transport very quickly, even with the power of three tractors, so what would normally be a 20-minute drive took six hours to get each module from the port to the power station site.

“There was one more challenge of getting the modules to site,” says Hodel. “The roadways on the South Hedland site were not suitable for a load of that size, so we constructed a 700 meter temporary access track from the highway. It took nine months alone for the temporary access track to be permitted and constructed in preparation for the delivery of the air cooled condensers.”

The first air cooled condenser arrived at our South Hedland site on December 18 and the second on January 21. The modules are currently sitting on their foundations ready to be raised up by approximately 13 meters to allow for the required air flow under the towers. Once raised, the towers will be 38m high, or almost as high as nine double decker buses placed on top of each other.

Air cooling condensers help to reduce the power station’s evaporative water consumption. The waste heat from the power station will be used to create steam, which then passes through a turbine to generate additional power. The steam must then be cooled back into water before it can be reused. This is where the air cooled condensers come in by using air drawn up from the fans and pushed through the condenser units to create the required cooling effect for the water to return to the turbines to produce more power.

“These two large air cooled condensers units at South Hedland are an inaugural additional to TransAlta’s fleet and the project team is excited to deliver this new addition,” says Hodel. “They are critical elements of the South Hedland power station design and integral in allowing the station to supply our customers extremely efficiently and with low water usage.”