Distributed exergy-based simulation-assisted control of HVAC supply chains

Generic model-assisted control algorithms for building energy systems achieve an energy-efficient building operation while the implementation effort is lower than in the case of a taylor-made automation system. In this paper, a generic distributed simulation-model-assisted and exergy-based control algorithm is presented, which is applicable to typical building energy systems (BES). It exploits dynamic nonlinear simulation models from an open-source Modelica library and makes use of sequential neighbor communication. In the supply chains of a BES, the algorithm performs multiple optimizations of small subsystems by considering pre-defined values of pre-defined coupling variables. The objective function is the sum of the exergy destruction and loss, which is based only on measurements without additional information such as monetary costs. In a simulation case study, an open-loop and a closed-loop version of the algorithm are compared to a control system based on rules and feedback controllers that was optimized manually for this particular scenario to provide a benchmark. The tracking error of the closed-loop algorithm is close to the benchmark. The open-loop algorithm achieves an energy consumption close to the benchmark. These results show that the algorithm finds suitable solutions automatically whereas the rule-based control system cannot be expected to perform equally well if boundary conditions were changed.