Optimal Chiller and Thermal Energy Storage Design for Building HVAC Systems

In the context of indoor building temperature regulation, a controller calculates the inputs for the HVAC system that result in appropriate thermal comfort conditions. Additionally, if electricity prices are time dependent, these control actions will also impact economic expenditures. To improve economic performance, Thermal Energy Storage (TES) is typically used in conjunction with HVAC to time-shift chiller cooling loads to times of low energy price. The method of Economic Model Predictive Control (EMPC) has been demonstrated to effectively reduce expenditures. Since TES and chiller sizes have a direct impact on achievable operational savings, an economic analysis considering the investment costs associated with these equipments is necessary. This work presents a novel algorithm intended to optimally select equipment sizes based on Net Present Value analysis and utilizing the recently developed methods of Economic Linear Optimal Control (ELOC) and constrained ELOC. Implementation of the numeric optimization is illustrated with a case study.