Optimisation of mechanical systems in an integrated building energy analysis program: part I, conventional central plant equipment

This is the first of two papers that describe the development of simulation methods for optimally controlled central plant equipment which have been implemented in the IBLAST (Integrated Building Loads Analysis and System Thermodynamics) building energy analysis program. In Part I, conventional central plant equipment is discussed, while Part II covers the simulation of optimally controlled thermal storage systems. The goal of conventional central plant optimisation is to minimise the operating cost of the plant equipment. A solution was achieved by using a GRG algorithm to minimise the energy consumption of each feasible equipment combination, for every simulation time step, then searching among these combinations for the one which resulted in the least energy cost. Results are presented for several combinations of conventional chilling and heating equipment.