Simulation of energy conservation measures and its implications on a combined heat and power district heating system: a case study

In this study a methodology for simulating large-scale energy systems is described. In particular the simulation of a district, supplied by a combined heat and power district heating system is the analysed energy system. In the methodology firstly, the districts’ space heating demand is modelled with the use of a simplified dynamic building model, developed in Modelica. Secondly, the districts’ domestic hot water demand is modelled by using the measured data and generating an average standard profile. Thirdly, the heat distribution is simulated by a simplified dynamic district heating network model, developed in Modelica. Finally, the CHP system-, boiler- and thermal storage-models are implemented in the statistical modelling environment GNU R as static models. These static models are used to calculate the operation of the heating systems by utilizing the simulated total heating demand as input, which are obtained by the above mentioned models. The methodology is presented by means of a case study. In this case study, a scenario is calculated, in which firstly, the change of a district’s heating demand profile due to energy conservation measures in buildings is explored. Subsequently, the implications of this demand modification on the supply side of the district heating system are investigated. It is shown, that the methodology developed in this study is appropriate, in order to investigate large-scale energy systems with similar boundary conditions as the presented case study. Additionally, due to the simulation results of the investigated scenario, it is shown how the refurbishment of a district has significant implications on a district’s combined heat and power district heating system.