MPC, VAV, pressure, air flow, AHU, HVAC system
A model of a variable air volume (VAV) system is developed that can predict air flow rates, fan pressure rise, and fan power consumption in response to changes in fan speed and damper positions. The system consists of a fan, ductwork, and a number of dampers, one in each VAV box. The model can be used for conducting simulation studies of how advanced control algorithms that seek to provide various services (energy efficiency, personalized comfort, and demand-side flexibility to the grid) may behave when deployed in a building with an existing climate control system, or to do model-based control computations for such services. Comparison of the model's predictions with experimental data from a small commercial building is presented for the single-zone version of the model. The multi-zone model structure is described, but its validation is left for future work. Due to the strong non-linearities in the steady state relation between inputs and outputs, and due to the fast transient response observed in experiments, the dynamic model is constructed to be of Hammerstein type, with a linear dynamic system in series with a static nonlinear model.