Copenhagen: Solutions for Sustainable Cities - Arup

CoolingOur solution in more detail//• Identification of co-located buildings - with coolingrequirements to ensure there was an adequatedemand for a district cooling network.• Building a new cooling station – with a capacityof 15MW and utilizing a combination of existingresources: seawater from the Port of Copenhagen inperiods where the seawater is sufficiently cold, andsurplus heat from the district heating network duringperiods of low heat demand.• Cooling: our solution – the use of excess heat fromthe district heating system during the summermonths (this also helps balance the district heatingsystem)• Integration of different principles of cooling – theplant was designed around three different methodsof cooling making it very flexible and highly energyefficient,depending on the temperature of theseawater:- Free Cooling – Seawater temperature is below 5.5degrees Celsius and cooling demand low (less than2400 kW). All cooling demands are covered by freecooling heat exchangers.- Combined operation – Seawater temperature isbetween 5.5 o C and 11.5 o C. Heat exchangers are usedfor pre-cooling of the cooled water, before it is fullycooled by chillers to the desired temperature.- Chiller cooling – Seawater temperature is above11.5 o C. The seawater is too warm to be used forfree cooling so absorption and compression chillersprovide all cooling. Free cooling heat exchanges arebypassed completely.The benefits of our newcooling system//• Environmental:- Carbon dioxide reduction of 67%, compared totraditional cooling. The annual sulphur dioxide andnitrogen oxide savings are 62% and 69% respectively.- Potential to negate or, at least, reduce the urbanheat island effect .- Demand for electricity is reduced becauseelectrically operated chillers are replaced by freecooling and heat operated chillers and DistrictCooling.- Excess heat, noise and chemicals from or usedin compressions chillers are avoided in individualbuildings.• Social:- Zero noise, in contrast to conventional coolingmethods- Removes many of the health risks associated withcooling towers e.g. Legionnaire’s disease.- Increased energy security from a centralised supplywith improved resilience built in.- Back up provision available.• Economic:- Reduction in expenditure for energy imports.- Cooling contracts with different organisationsand institutions can be replicable, allowing easytransferability.- Free up commercial, retail and parking spaces asconventional cooling systems and fan coils on roofsare replaced by underground infrastructure.• Created multiple connections to a network – DistrictCooling works on the same principles as districtheating. Chilled water is produced centrally andcarried to the end customers through a systemof pipes. Networks can be built adjoining districtheating pipework, or can be laid where no existingnetwork is in place.• Commercial development of network - are based onprofitable business cases.