Performance evaluation of a co-production system of solar thermal power generation and seawater desalination. (May 2021)

• Record Type: Journal Article
• Authors: Yuan, Liyuan; Zhu, Qunzhi; Zhang, Tao; Duan, Rui; Zhu, Haitao
• Is Part Of: Renewable energy. Volume 169(2021)
• Page Start: 1121
• Page End: 1133
• Publication Date: 2021-05
• Subjects: Supercritical carbon dioxide Brayton cycle -- Multi-effect distillation -- Solar thermal power -- Cogeneration; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2021.01.096
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Increasing power cycle efficiency is an important way to reduce the cost of the solar thermal power generation. The power generation system using a supercritical carbon dioxide (s-CO2 ) Brayton cycle has the advantages of high cycle efficiency, small equipment size and low corrosion. Then, low temperature waste heat generated by the s-CO2 Brayton cycle can be used as the low temperature heat source for multi-effect desalination. This paper discusses a s-CO2 Brayton cycle integrated with a multi-effect seawater desalination system. The heat input of the s-CO2 Brayton cycle is from a central-tower solar receiver. The residual heat of the s-CO2 Brayton cycle is the heat input of the multi-effect distillation system. The results show that the integration of multi-effect desalination system does not affect the s-CO2 Brayton cycle efficiency. With the increase of split ratio of the compressor, Brayton cycle efficiency increases and then decreases, and the water production decreases and then increases. With the increase of turbine inlet temperature, Brayton cycle efficiency increases while freshwater production varies insignificantly. After optimizing the design of the cogeneration system, solar thermal power efficiency is 24.04%, the cost of electricity generation can be reduced, the LCOE is 0.081$/kWh. by using the waste heat generated from the power cycle. realized electricity-water cogeneration, the fresh water production from 5-effect MED is 459m 3 /day, and the unit cost of freshwater UPC of 0.81$/m 3 . Highlights: The MED generation without affecting the Brayton cycle efficiency. PRWH and freshwater yield increase with inlet temperature of seawater. Water yield of the MED system does not vary with the turbine inlet temperature. Optimization and economic analysis of the cogeneration system are carried out.