Unidirectional Low Temperature Thermal Networks: Enabling Thermal Distributed Energy Resources

Abstract

This thesis investigates the potential of Unidirectional Low Temperature Thermal Networks (UD-LTTN) as a means to improve community-level energy efficiency through the integration of Thermal Distributed Energy Resources (TDER). UD-LTTN systems are the next generation of District Heating and Cooling (DHC) systems, and utilize decentralized heat pumps to enable distributed generation, reduce thermal pipe losses and decrease system-wide exergy destruction. By providing these benefits, these systems have the potential to decrease the total energy utilization of a community, when compared to traditional DHC systems. To better understand the potential of UD-LTTN systems, an equation-based modelling library was created in the open-source simulation code “Modelica.” This library was then used to perform a comparative analysis between both a UD-LTTN system and DHC system when applied to the same case study. This analysis compared each system based on total energy utilization and carbon emission production for a variety of cases. Additional thematic analysis was then done to understand how the comparative analysis results extend to the more general field of UD-LTTN system design. The results found that UD-LTTNs systems can reduce the total energy generations requirements by capturing energy from decentralized waste energy resources within the community. However, other factors such as electrical generation sources, peak power capacity and pumping power requirements are important considerations when determining the true effectiveness of these innovative systems.