District Cooling Network Planning. A Case Study of Tallinn

Abstract

The planning procedure for district cooling as an urban system was described and implemented using the example of the city centre of Tallinn. The following steps were described in detail: determining cooling demand, planning cold supply and analysing cold water distribution. Based on the three proposed methods (average specific cooling load, satellite imagery analysis of a specific building, dry cooler fan counting, and the combination method), the cooling capacity of the evaluated district was estimated at 63.2 MW. In terms of cold supply, the analysis showed that free cooling with seawater can cover up to 55% of the annual cooling demand. Electric chillers and absorption chillers that use excess heat can cover the rest of the district’s cooling demand. The district cooling network was designed for three scenarios: single generating unit, two generating units and a looped network. Despite the fact that the looped network is the most expensive option, it is deemed feasible as it simplifies the connection of new consumers.