COWI designs district cooling for new metro in Qatar

Date: 18/05/2016

​The demand for district cooling is on the rise. This also counts for oil and gas rich Qatar where part of the cooling in the upcoming Doha Metro will be delivered by a district cooling system.

Qatar Rail has chosen to change part of the planned decentralized cooling with dry air cooled chillers at each stations in favor of a more energy efficient district cooling system in the upcoming Doha Metro, where some 130 COWI engineers are leading the design work on the Red Line North Underground consisting of two tunnels of each 13 kilometers and 7 underground stations.

“The advantage of district cooling is that is it is far more energy efficient and much less space consuming than decentralized cooling with dry air cooled chillers on each station,” says design manager Niels Vilstrup, COWI. With desert temperatures well over 50° C, the Doha Metro’s cooling system is decisive for the operation, safety and comfort of the metro stations as well as inside the tunnels if a train breaks down.

Cooling more with less
The demand for district cooling is rising around the world due to urbanisation, climate change and a need for more energy efficient solutions.In general, a bigger district cooling system can be up to 40-50% more energy efficient than a decentralized cooling system.Originally, the tunnel concrete walls in the Doha Metro are not designed to support heavy waterfilled 18” cooling pipes needed for a district cooling system. Moreover, the tunnels have many curves and height differences putting high demands on the flexibility of the pipes and especially on the design of pipe supports.”It has taken many unique and creative solutions to make it work, but fortunately we have an advantage, because of our specialists both within tunnel construction, pipe design and district cooling design,” says Niels Vilstrup.A COWI led design Joint Venture is responsible for designing all Civil Works, MEP (mechanical, electrical and plumbing) and architetural work on the Red Line North Underground, a central part of the Doha Metro System.

FACTS

  • ​21 Tunnel Boring Machines and 27.000 people from all over the world are working full speed to finish off 113 kilometers metro tunnels and 74 stations for Qatar Rail in Doha.
  • The metro system will consist of 4 metrolines.
  • Qatar’s overall objective is to improve the existing public transpor infrastructure and reduce urban congestion by 2030.