Thermodynamic and economic analyses of nuclear power plant integrating with seawater desalination and hydrogen production for peak shaving.

An integrated system incorporating a nuclear unit, multi-stage flash desalination, and proton exchange membrane electrolyzer is proposed for peak shaving. The extraction steam is used for seawater desalination to produce freshwater, the generator output power is employed to drive the electrolyzer for hydrogen production, and the electrolyzer outlet water heats the feedwater for power boosting. Thermodynamic analysis shows that 53.76 MW is used for seawater desalination-hydrogen production (electrolyzer voltage =2.0 V). The system efficiency is 37.44 % with output hydrogen energy of 37.86 MW, and the specific energy consumption is 4.72 kWh/Nm3. The electrolyzer exergy efficiency of the integrated system is 81.94 %, higher than the standalone electrolyzer with 61.17 %. Sensitivity analysis shows higher voltage and lower water flow rates are conducive to higher hydrogen production rates. Economic analysis shows that the cost of hydrogen production is 15.16 CNY/kg and the annual net income can reach 7.68·106 CNY. • Nuclear unit coupled with MSF desalination and PEM electrolyzer for polygeneration. • Whole-process seawater desalination-hydrogen production for peak shaving. • Real internal temperature distribution of the electrolyzer is revealed. • The integrated system is subject to thermodynamic and economic analysis. [ABSTRACT FROM AUTHOR]