Sequential optimization of a polygeneration plant

• Published in: Energy conversion and management 2011-08, Vol.52 (8), p.2861-2869
• Main Authors: Rubio-Maya, Carlos, Uche, Javier, Martínez, Amaya
• Format: Article
• Language: English
• Subjects: Applied sciences; CCHPW; Combined power plants; Cooling; Desalted water; Design engineering; Drinking water and swimming-pool water. Desalination; Economic data; Economics; Electric energy; Energy; Energy economics; Energy storage; Energy. Thermal use of fuels; Exact sciences and technology; General, economic and professional studies; Installations for energy generation and conversion: thermal and electrical energy; Operation; Optimization; Pollution; Polygeneration; Power plants; Superstructures; Synthesis; Tourist sector; Water treatment and pollution
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2011.01.023

► A two-steps optimization procedure of a polygeneration unit was tested. ► First step was the synthesis and design; the superstructure definition was used. ► Second step optimized the operation with hourly data and energy storage systems. ► Remarkable benefits for the analyzed case study (Spanish hotel) were found. This paper presents a two-steps optimization procedure of a polygeneration unit. The unit simultaneously provides power, heat, cooling and fresh water to a Spanish tourist resort (450 rooms). The first step consist on the synthesis and design of the polygeneration scheme: a “superstructure” was constructed to allow the selection of the appropriate choice and size of the plant components, from both economic and environmental considerations. At that first step, only monthly averaged requirements are considered. The second step includes hourly data and analysis as well as energy storage systems. A detailed modelling of pre-selected devices is then required to also fulfil economic and environmental constraints. As a result, a better performance is obtained compared to the first step. Thus, the two-steps procedure explained here permits the complete design and operation of a decentralized plant producing simultaneously energy (power, heat and cooling) but also desalted water (that is, trigeneration + desalination). Remarkable benefits for the analyzed case study are found: a Net Present Value of almost 300,000 €, a primary energy saving ratio of about 18% and more than 850 ton per year of avoided CO 2 emissions.