Strategy for designing more energy efficient chiller plants serving air-conditioned buildings

In cities located in the subtropical regions, air-cooled chillers are commonly used to cool commercial buildings almost year-round, which accounts for considerable electricity consumption in the long term. This paper explains how a chiller plant should be designed to enable the chillers to operate frequently with maximum performance. Four design options with respect to the number and size of chillers were studied for a chiller plant satisfying the year-round cooling demand of a hotel. For each design option, the annual electricity consumption of chillers and pumps was assessed using a sophisticated chiller model. The assessment showed that an electricity saving of 10.1% can be achieved by installing a chiller plant with six chillers of three different sizes instead of four equally sized chillers. The results of this paper will give engineers and researchers a better idea about how to select chillers of different sizes and how chiller part load performance curves can be used to evaluate improvements in the energy performance of a chiller plant with alternative designs.