Operational optimization of district heating system based on an integrated model in TRNSYS

The time-varying feature of heating loads of public buildings creates a considerable space for exploring control strategies of matching the balance between the supply and demand side of district heating system (DHS). However, the strong coupling relationship between hydraulic conditions of each building has brought great difficulties for the operation regulation of DHS. Therefore, an operation strategy based on real-time indoor temperatures was proposed and a new integrated model based on dynamic hydraulic conditions combining with real-time temperatures were developed. The integration model-based strategy selects the operation costs as the main objective function and then a set of optimum neighborhood points were acquired according to the optimum financial point. Finally, the optimum operation solution was determined with consideration of the thermal comfort factor. By this decision-making process, the approach is available to obtain the operation solution which can guarantee a more comfortable indoor environment from energy point of view with a slight increase of financial expenditure. A university campus in Harbin was chosen as the case study to investigate optimization strategy and to evaluate the optimization results. The results showed that, compared with the current experience-based operation procedure, operation costs of heating system can be maximumly cut down by 38.18% with satisfying the requirement of indoor thermal comfort.