Extended Node Method for Steady-State Heating Network Calculation based on Electric Analogies

In the context of a multi-energy-grid, the consideration of various energy carriers on the same level is beneficial. This work shows the development of heating network components in electric analogies for their definition and usage in the node-based Extended Node Method. The method enables an efficient iteration algorithm for finding of stable steady-state operation points, even for extended network topologies. Three different thermal equivalent circuit diagrams, a ladder-, Pi- and T-model, describing the thermal behavior of heating pipelines are presented. They simultaneously fulfill the thermodynamic energy balance as well as the electrical equivalent circuit diagram correlations. The influence of the spatial resolution is tested using a single-line model. Moreover, a steady state calculation is also performed for an 18-node sample network. All results are compared with Simulink/Simscape and show satisfactory agreements.