Evaluation of losses in district heating system, a case study

• Main Authors: Vesterlund, Mattias, Sandberg, Johan, Lindblom, Bo, Dahl, Jan
• Format: Conference Object
• Language: English
• Published: Luleå tekniska universitet, Energivetenskap 2013
• Subjects: District heating; Evaluation; Losses; Pipe series; Case study; Energy Engineering; Energiteknik; Kiruna; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-35161

To be able to create a model that accurately describes a district heating system, it is important to identify the thermal losses and how they are distributed. However, general methods targeting the determination of losses are scarce in the literature. In the current case the losses for a district heating system in Kiruna, a town in northern Sweden, has been estimated in the year 2010 to be 12%, which is in the range for a typical Swedish network. Unfortunately, detailed information of the thermal losses is lacking.In this paper two methods to determine loss distribution in a district heating system are presented.Two databases of pipe lengths and diameters have been compiled for two piping categories, loops and feeds. Any missing data regarding pipe diameters in the map has then been determined with the two different methods.In the first method average pipe diameters for loops and feeds are calculated. All pipes with unknown diameter are then assumed to have the average one. The second method considers a percentage based distribution of known diameters and assigns the same distribution to the missing pipe diameters. The losses were estimated in the whole system according to the data from a pipe producer catalogue, in which losses are calculated according to current European standard. The results show that the losses in the system are similar to the losses caused by pipes with the lowest insulating capacity.By using the two methods two fictitious pipe series reproducing exactly the losses in the system are created by scaling the calculated losses of the catalogue pipe series which would give the most similar losses (the one with the lowest insulating capacity). This adjustment was +3.1% by using the first method, and +4.9% by using the second method.The major conclusion of this study is that, both methods can be used for calculating the distribution of thermal losses in the district heating system of Kiruna; moreover, this kind of analysis can be an important tool for analyzing investments in the district heating ...