Application of the genetic algorithm and downhill simplex methods (Nelder–Mead methods) in the search for the optimum chiller configuration

Abstract

Methods for searching for the optimum chiller configuration for a heat source plant were examined. In addition to the genetic algorithm (GA), a hybrid of the GA and the Nelder–Mead downhill simplex method was developed. By using the Nelder–Mead downhill simplex method, fewer calculations were required to determine the optimum chiller configuration. Due to applying the GA, the calculations for the developed system did not become trapped in a local optimum, and the algorithm could then determine the global optimum after a few iterations of the Nelder–Mead downhill simplex method.The performance of the developed system was examined for the heating/cooling energy plant of a building; the plant consisted of a centrifugal chiller, a gas-fired absorption chiller, air-source heat pumps, and boilers. It was confirmed that the ability of the GA to find the optimum configuration for the chiller was improved by combining the GA with the Nelder–Mead downhill simplex method.