The city of Copenhagen, Denmark has installed a district cooling system which is based on free cooling from seawater abstraction, along with running surplus heat from the district heating network through absorption cooling and compression chillers.
The Adelgade District Cooling Energy centre in Copenhagen, has an installed capacity of 15 MW cooling. The energy centre delivers piped chilled water to nearby buildings that include Banks, Hotels, Museum, offices and a Mint. A 3.5 MW Thermax steam driven absorption chiller is part of the 15 MW installed capacity. A local district heating plant supplies steam to Thermax’s chiller. Sea water from a 19th century canal is used for heat rejection, thereby eliminating investment and subsequent maintenance associated with cooling towers. The absorption chiller circuits are made with special materials to handle sea water.
The new cooling network complements the city’s existing heating system covering 98% of Copenhagen. The new project of 15 MW capacity is expected to save 14,000 tonnes of carbon dioxide per year. Copenhagen’s district cooling system reduces carbon emissions by nearly 70% and electricity consumption by 80% compared to conventional cooling.
During the summer months when demand is low there is an excess surplus heat within the district heating system. The excess heat is used to drive Thermax’s steam double effect absorption chiller to produce chilled water for the city’s cooling needs.