Techno-economic analysis and simulation of low temperature district heating networks

Sammanfattning: The continuous increase in global energy consumption has led to a greater focus on the energy required for heating buildings. This thesis presents a techno-economic model for analysing low-temperature district heating networks coupled with a geothermal heat source. The model was used to analyse an existing system in Denmark with 15 connected single-family detached houses. Each of the houses has a substation with a decentralised heat pump. Measured data was used to validate the model based on the temperature levels at the evaporator side of each building heat pump. The results revealed that the analysed system benefits from using uninsulated pipes, which receive heat gains from the ground, improving the system's temperature quality. However, according to the simulation results, the efficiency of the system and its economic and environmental performance have room for improvement, mainly due to the ground heat depletion problem. From a hydraulics point of view, the simulated system has the potential to function efficiently, having relatively low-pressure drops on the bore field level, which is beneficial for the SPF of the system. Several solutions were proposed to increase the efficiency, and a preliminary direction for future studies was discussed.