Optimal control of chilled water systems based on collaboration of the equipment's near-optimal performance maps

Abstract

The model-based strategies have been widely used for optimization of energy consumptions of chilled water systems. The strategies usually establish the system’s energy consumption models, and use optimization algorithms to search the optimal setpoints. However, the models of these strategies may be inaccurate, and the nonlinearity of the models will cause a large amount of computational load. In order to solve the problems, this paper set up the near-optimal performance maps of system equipment instead of models based on operation data. Each map indicates the highest or near-highest operation efficiency of a kind of equipment under the different operation conditions. A novel control strategy for optimization of chilled water systems is developed based on collaborating those maps. An airport chilled water system which is located in the south of China is used for validation. The proposed strategy is compared with two conventional strategies on the chilled water system. Results show that the proposed strategy can not only significantly save the energy consumption of the system, but also has a lower computation time, so the proposed strategy can be better applied to online optimization control.