Energetic and exergetic analysis of cogeneration power combined cycle and ME-TVC-MED water desalination plant: Part-1 operation and performance. (25th June 2016)

• Record Type: Journal Article
• Authors: Almutairi, Abdulrahman; Pilidis, Pericles; Al-Mutawa, Nawaf; Al-Weshahi, Mohammed
• Is Part Of: Applied thermal engineering. Volume 103(2016:Jun.)
• Page Start: 77
• Page End: 91
• Publication Date: 2016-06-25
• Subjects: Cogeneration -- Desalination -- Gas turbine -- Exergy -- HRSG -- Reheat -- Destruction; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.02.121
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Develop a comprehensive model for a very advanced cogeneration plant using real data. Evaluate ME-TVC-MED unit using the latest thermodynamic properties of seawater. Evaluate the desalination unit contribution to the overall efficiency. Evaluate the stage exergetic efficiency in the ME-TVC-MED unit. Numerous possibilities have been suggested to improve the proposed system. Abstract: A comprehensive model of cogeneration plant for electrical power and water desalination has been developed based on energetic and exergetic analyses using real operational data. The power side is a combined cycle power plant (CCPP), while the desalination side is a multi-effect thermal vapour compression plant coupled with a conventional multi-effect plant (ME-TVC-MED). IPSEpro software was utilized to model the process, which shows good agreement with the manufacturer's data and published research. The thermodynamic properties of saline water were obtained from the latest published data in the literature. The performance of the cogeneration plant was examined for different ambient temperatures, pressure ratios, loads, feed water temperatures, number of effects and entrainment ratios. The results show that gas turbine engines produce the highest level of useful work in the system at around 34% of the total fuel input. At the same time, they constitute a major source of irreversibility, which accounts for 84% of the total exergy destruction in the plant, while the lowest source of irreversibility is in the steam turbine of 3.3% due to the type of working fluid and reheating system. In the ME-TVC-MED desalination unit, the highest source of irreversibilities occurs in the effects and in the thermo-compressor. The first two effects in the ME-TVC parallel section were responsible for about 40.6% of the total effect exergy destruction, which constitutes the highest value among all the effects. Operating the system at full load while reducing ambient temperature, and increasing pressure ratio and feed water temperature, were strongly recommended in order to improve the plant's performance; while increasing the number of effects is always preferable with low entrainment ratio for high cogeneration plant performance and capacity.