Dynamic simulation and thermoeconomic analysis of a novel solar cooling system for a triple-pressure combined cycle power plant. (15th August 2018)

• Record Type: Journal Article
• Authors: Calise, Francesco; Libertini, Luigi; Vicidomini, Maria
• Is Part Of: Energy conversion and management. Volume 170(2018)
• Page Start: 82
• Page End: 96
• Publication Date: 2018-08-15
• Subjects: Dynamic simulation -- Solar assisted triple-pressure combined cycle -- Flat evacuated collector -- Absorption chiller; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2018.05.041
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: A dynamic simulation model of a novel integrated solar cycle is presented. A solar cooling system is coupled to a triple-pressure Combined Cycle power plant. Plant efficiency and capacity are improved by reducing air inlet temperature. A special strategy is developed to limit water condensation. The payback period was about 10.7 years. Abstract: This paper presents the design of a novel high-temperature solar assisted triple-pressure level combined cycle power plant. The system includes innovative high-temperature flat plate evacuated solar thermal collectors, a double stage lithium bromide/water absorption chiller, pumps, heat exchangers, storage tanks, mixers, diverters, controllers and a triple-pressure combined cycle power plant. This novel layout uses high-vacuum non-concentrating flat plate solar thermal collectors driving a double effect absorption chiller, leading to an overall high coefficient of performance for the solar cooling section. The provided cooling energy is used to cool gas turbine inlet air to enhance system efficiency and electrical capacity. This effect is mainly performed during central hours of the day when the conventional gas-fired combined cycles dramatically suffer for efficiency and capacity reduction, as a consequence of the corresponding increase of external air temperature. Such increase is related to the higher availability of solar radiation. This technology may be a viable solution, especially for hot and dry areas, in terms of primary energy savings and increased revenues. This prototypal system was numerically analysed for a combined cycle with a rated electrical power of 99 MWe and an electrical efficiency of 56%, developing a dynamic simulation model and detailed thermo-economic optimizations. Special attention is also paid to the design of novel control strategies aiming at maximizing the solar cooling effect. The results of the dynamic simulations show a very high average thermal efficiency of the solar collectors, equal to 34%. Implications of the performed work allowed an increase of the power output up to 5.5% and a satisfactory payback period equal to 10.7 years.