Planning of production and utility systems under unit performance degradation and alternative resource-constrained cleaning policies

• Published in: Applied energy Vol. 183; pp. 577 - 602
• Main Authors: Zulkafli, Nur I., Kopanos, Georgios M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2016
• Subjects: Cleaning; Combined heat and power; Energy planning; Optimization; Performance degradation; Production planning; Utility system; Production planning; Energy planning; Cleaning; Performance degradation; Combined heat and power; Utility system; Optimization
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2016.08.060

•A model for the simultaneous planning of production and utility systems is presented.•The performance degradation and recovery is modeled for the utility units.•Alternative cleaning policies are modeled under limited cleaning resources.•Fixed and variable operating, cleaning and power consumption costs are optimized.•Industrial-inspired case studies show the benefits of the proposed approach.•Reduction in utilities purchases and startup, cleaning and power consumption costs. A general optimization framework for the simultaneous operational planning of utility and production systems is presented with the main purpose of reducing the energy needs and material resources utilization of the overall system. The proposed mathematical model focuses mainly on the utility system and considers for the utility units: (i) unit commitment constraints, (ii) performance degradation and recovery, (iii) different types of cleaning tasks (online or offline, and fixed or flexible time-window), (iv) alternative options for cleaning tasks in terms of associated durations, cleaning resources requirements and costs, and (v) constrained availability of resources for cleaning operations. The optimization function includes the operating costs for utility and production systems, cleaning costs for utility systems, and energy consumption costs. Several case studies are presented in order to highlight the applicability and the significant benefits of the proposed approach. In particular, in comparison with the traditional sequential planning approach for production and utility systems, the proposed integrated approach can achieve considerable reductions in startup/shutdown and cleaning costs, and most importantly in utilities purchases, as it is shown in one of the case studies.