Transformation of conventinal heating networks towards low temperature networks with secondary measures

01.04.2017 - 31.03.2021
Research funding project
District heating currently supplies more than 20% of the Austrian delivered energy for space heating and domestic hot water purposes. This share has increased significantly within the past 10-15 years and it is expected that this trend will continue in the coming years. However
it is assumed that expansions of district heat supply in Austria will primarily occur in areas, in which heat networks already exists to some extent today.
The aim of the project T2LowEx is to increase the efficiency of those networks and facilitate the integration of renewable low-temperature energy sources (e.g. solar thermal energy).
Decreasing the required supply and return line temperatures of such networks - ultimately towards Low-Exergy heating networks - is the key to reach these targets. The quality management (qm) program qm heizwerke as well as international experience in this field clearly indicates that particularly older networks show huge improvement potentials, but also newly constructed networks are far from being optimally designed with respect to temperatures levels.
This efficiency potential can be fully exploited only, if the implemented measures also target the supplied heat consuming facilities and buildings (secondary heating system) as they define the temperature levels demanded by the primary heating network.
By setting the supplied heat consuming facilities and buildings (secondary heating network) into the center of the analysis, the proposed project fundamentally differs from previous projects, which mainly focused on the primary heating network (generation & distribution).
We intend to systematically explore the status and performance of existing buildings connected to district heating networks with regard to temperature levels to find answers for the following research questions: a) which methods allow for automatically identifying cost efficient measures to reduce temperature levels of existing customers in heat networks; b)
which stakeholder profits to which extend and who is going to bear the costs of these efficiency measures; c) which tariff and business models provide incentives for customers
and grid operators to implement measures to reduce temperature levels.
We will perform model and measurement based analyses in case studies for at least five existing district heating grids (among others grids in Salzburg, Vienna, Gleisdorf, Ried). In the course of the project we will monitor the performance of existing buildings in detail, analyze and evaluate optimization potentials and implement and monitor at least 50 selected measures. These on-site activities will be accompanied by comprehensive thermodynamic computer simulations to identify and evaluate additional optimization potentials under varying conditions. Finally, we will transfer the results of the case studies to an Austrian-wide level by utilizing data gathered within the qm heizwerke program and other sources. From this we will draw general conclusions and recommendations for actions to be taken by grid operators and energy policy makers to achieve lower temperature levels in existing heat networks in a cost efficient way.

People

Project leader

Project personnel

Institute

Grant funds

  • FFG - Österr. Forschungsförderungs- gesellschaft mbH (National) Group Thematic programme Austrian Research Promotion Agency (FFG)

Research focus

  • Climate Neutral, Renewable and Conventional Energy Supply Systems: 100%

Publications