District Cooling Network Planning. A Case Study of Tallinn

The planning procedure for district cooling as an urban system was presented and carried out using the example of the Tallinn city centre. The following steps were described in detail: cooling demand determination, cooling generation planning and cooling transition analysis. Based on the three proposed methods (average specific cooling load, satellite imagery analysis of a specific building, counting the number of fans in dry coolers and the combination method), the cooling capacity of the evaluated district was estimated at 63.2 MW. In terms of cooling generation, the analysis shows that seawater for free cooling can cover up to 55% of the annual cooling consumption. Electric chillers and absorption chillers that use surplus heat can cover the rest of the district cooling demand. The district cooling network was designed for three scenarios: with one generating unit, with two generating units and a looped network. Despite the fact that the looped network is the most expensive option, this type of solution is considered feasible as it will make it easier to connect new consumers.