Optimal operation and cleaning scheduling of air coolers in concentrated solar plants

Abstract

Concentrated Solar Power (CSP) plants capture abundantly available solar radiation and offer a renewable energy supply. The optimal design and operation of air coolers in such plants is key to their efficiency, however their dynamic performance is impaired due to fouling and variable external conditions. First, the air cooler section design is optimally designed in a modular way, enabling their use as a network of exchangers that can be operated independently. Then, exploiting the extra degrees of freedom, their simultaneous optimal operation and cleaning scheduling over 10 years is considered using a suitable formulation, with an economic objective function. Seasonal variability and operating conditions uncertainty are included. The resulting mixed-integer non-linear programming (MINLP) problem is solved efficiently using a Benders decomposition approach. Results are presented for two realistic CSP plants in Almería (Spain) and Dubai (United Arab Emirates), which have different external and weather conditions. The optimal solution reduces operating cost and defines optimal cleaning policies which are location dependent.