HeatNetSim: An open-source simulation tool for heating and cooling networks suitable for future energy systems

Low temperature district heating and cooling networks are a promising solution to increase the share of renewable energy within the heating and cooling sector. However, the transition to bidirectional networks poses new challenges (representation of fluid-specific properties, coordinate operation with power grid, retrofitting of existing networks) requiring a new generation of simulation tools. In this paper, we present a simulation tool for thermal networks capable of bidirectional flows, zero mass flows and a dynamic temperature calculation. The structure of the tool allows coupling to other sector’s simulation tools enabling multi-domain analysis of relevant interactions with power and gas grids. We showcase the tool with two case studies inspired by the heating and cooling infrastructure of our campus. The first case study analyzes the operation of a unidirectional high temperature district heating network supplied by a power-driven combined heat and power plant. The case study highlights the suitability of district heating networks as a source of flexibility to the power grid by using its thermal inertia. The second case study investigates the transition from independently operated district heating and district cooling networks into a bidirectional low temperature district heating and cooling network highlighting the energy saving potential by thermal balancing effects.