Optimal operation of a combined cooling system

The effectiveness of Concentrated Solar Power (CSP) plants is significantly influenced by the temperatures at which steam condensation occurs. The existing cooling systems, whether wet (water-cooled) or dry (air-cooled), involve trade-offs. Wet cooling enhances performance but raises concerns due to substantial water usage, particularly in water-scarce regions where CSP plants are often located. On the other hand, dry cooling conserves water but at the cost of reduced efficiency, especially during high ambient temperatures that coincide with peak electricity demand. A possible compromise solution involves a combined cooling system that integrates both wet and dry methods, providing flexibility for overall reduced water consumption and enhanced efficiency. The incorporation of such systems into CSP plants is thus of great interest, owed to the potential adaptability of its operation to changing conditions. In order to make this optimally and feasible, a suitable control system needs to be developed. In this work we present the first implementation, in a real pilot plant, of a two-layer hierarchical control strategy, where the upper layer solves a multi-objective optimization problem for conflicting water and electricity consumptions, and a regulatory PID-based control layer adapts the system operation to the generated optimal references. Copyright (c) 2024 The Authors. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)