District cooling: Copenhagen, home of the largest absorption chiller cooling

A recent report by the City of Copenhagen, home of the largest absorption chiller cooling, network gives a glimpse of its district cooling system which uses seawater and surplus heat from the district heating network (through absorption cooling and compression chillers).
A recent report by the City of Copenhagen, home of the largest absorption chiller cooling, network gives a glimpse of its district cooling (DC) system which uses seawater and surplus heat from the district heating network (through absorption cooling and compression chillers).

A new 15 MW-capacity cooling system complements the existing district heating system which covers 98% of the city and is expected to prevent 14 000 tonnes of CO2 emissions per year. It is claimed to reduce carbon emissions by almost 70% and power consumption by up to almost 80% compared with conventional cooling.

The first DC cooling plant, a 10 MW facility, was implemented in 2010. In the summer, the excess heat from the district heating system is used to drive a double-effect absorption 3400 kW chiller operating with lithium bromide/water to produce chilled water for the city’s cooling needs.
The chilled water is partly cooled thanks to cold seawater from the city’s harbour, with three different methods according to the temperature of the water: when the seawater is below 5.5°C and cooling demand is under 2400 kW, all the cooling demands are covered by the free cooling exchangers; when the seawater is between 5.5 and 11.5°C, a combined operation system uses the seawater to pre-cool the water before it is fully cooled by chillers and when the seawater is over 15°C, the free-cooling chillers are bypassed, in chiller-cooling mode.