Development of Supervisory Control Strategy for Online Control of Central Cooling Water Systems

This paper presents a model-based supervisory control strategy for online control of building central cooling water systems to enhance their energy efficiency. Simplified chiller and cooling tower models are developed and used to predict the system energy performance, environment quality as well as the system response to the changes of control settings. A novel and simple optimization technique, named as PMES method, is developed and used to seek the optimal control settings under the given working conditions. The performance of both simplified models is validated using the field measurement data and/or the factory performance test data while the performance of this model-based supervisory control strategy is evaluated by comparing with that of near optimal control strategies and other conventional control strategies for cooling water systems through simulations. The implementation issues of the supervisory control strategy for practical applications are also presented.