Energy conservation on a central chiller plant

Abstract

Air-conditioning is no more treated as a luxury but a day to day requirement essential for the human comfort and productivity. When compared among different sub systems of a building, air-conditioning subsystem is responsible for the largest proportion of the energy consumption especially in a tropical climate like Sri Lanka. Central air-conditioning that comprise of a chiller plant is the most common means of air-conditioning in large commercial buildings. Hence successful energy optimizations that are implemented on a central chiller plant will definitely result with large financial savings. Even though it is a known fact that all individual components that comprise a central chiller plant are now optimized in terms of energy efficiency, the overall behavior of the entire system once these pieces are put together is something that has to be separately worked out. This research proposes and implements energy optimizations on top of a central chiller plant. It evaluates the amount of saving from each optimization and presents a practical model to follow in a similar plant. Energy optimizations proposed in this research were implemented in conjunction with the capabilities of the central chiller plant control system that is already available at the site for the purpose of real time monitoring and controlling of the central chiller plant. Results of energy saved was quantified using the run hour reading gathered prior and after the implementation of the optimizations. A saving of 15.8% from COW pumps, 23.8% from CHW pumps and 32.8% from CTs were achieved as a result of those optimizations. Outcomes of this research can be made use by different parties including investors and decision makers of buildings to promote similar energy saving projects in their organizations.