A fast and effective method for modelling and optimizing district heating systems in the Modelica language

A district heating system is a centralized energy that supplies heat to end users such as buildings and industrial facilities. This may have multiple sources, complex distribution network, large number of users. Moreover, the utilization processes entail tumultuous thermal dynamics. Therefore, modelling optimizing generally demands arduous labour necessitates powerful computing resources. To overcome these difficulties, this study introduced fast effective method for systems using Modelica language. Firstly, simplified model was developed. lumped all end-users into single pinot with critical physical constraints. Meanwhile, network two pipelines: supply return. In addition, one-dimensional discrete used describe behaviours water tank storage. Other essential components, like central distributed were modelled basic mass balance equations. Afterwards, optimization frameworks formulated, which incorporated developed model: long-term optimal operation framework aimed at yearly level open-loop two-hour resolution, predictive control daily close-loop one-hour resolution. The proposed tested numerically on university campus in Norway personal computer. Model validation showed approach could capture key characteristics studied system. Optimization results demonstrated effectiveness both short-term optimization.