On the road to low temperature district heating

Abstract

The roadmap to implementation of low temperature (LT) grid taking into account existing district heating (DH) systems is analysed in the paper. Lessons learned from pilot cases in Albertslund, HojeTaastrup, Kalundborg and Łomża are presented. Also in Albertslund and Hoje Taastrup LTDH grids constituting subgrids of the main (third generation) DH grids, and the last is fed from the DH return-flow. In Kalundborg an independent ultra-LTDH grid is considered to utilize the low temperature surplus heat (around 20C) as supply for Municipalities located nearby. In Poland the effects of a lower supply temperature in an entire DH grid were investigated. This lower supply temperature was effective on account of the existing DH-grid infrastructure being oversized.