First Experiences with Coupled Dynamic Simulation of Building Energy Systems and the District Heating Network

The concept of distributed generation of energy attracts increasing attention nowadays. Such an environment requires new tools to handle the sophisticated multi-production and multi-consumption phenomena in the transmission networks to enhance the quality of the design and to optimize the use of the energy system. The distributed computing with certain rules enables totally new dynamic simulations for the energy system. For example buildings, district heating networks and power plants can be simulated synchronized as a whole system. Our approach utilizes generic ICT-components and interfaces used in distributed computing environment to handle coupling challenge between different simulation platforms. The distributed solution environment can be run over the Internet or LAN-networks. Using distributed simulation considerably accelerates computation, but simultaneously some time is spent on communication between the simulators and the integrator program. It was found that inter-simulator communication of data may take approximately 20-25 % of the total simulation time. This was based on an assumption that more intensive computing (short time step) was required during the hot water tapping peaks. The time share of communication may be even higher if simulated case has frequent energy peaks and a high degree of accuracy for the results is required. For optimal performance in the future, the models should be able to recognize steep gradients and adjust the time step accordingly.