The volume flow in a thermal circuit in my model is not constant at every point. How can this happen?

Green City models utilise existing knowledge to increase simulation performance. This includes the fact that the direction of the media flow in a heating system is usually unidirectional. In order to avoid numerical problems in the model (i.e. overdetermination of the system of equations), only the output volume flows are set in the ‘Pump’ model and the input volume flow is not included in the model. Therefore, when modelling, make sure that the input flow rate always corresponds to the target/output flow rate of the pump.