Evaluation of the efficiency of combining wet-steam NPPs with a closed hydrogen cycle

Abstract

Combustion of hydrogen in oxygen allows to produce high-temperature steam, which can be used to generate electricity in cycles of thermal power plants. Depending on combustion conditions the temperature of the generated steam can reach 3500-3600 K under the pressure of 6 MPa. The existing technical solutions imply direct injection of the cooling water or steam into combustion products to reduce the temperature and feed the resulting mixture into the steam cycle. The system of safe hydrogen steam superheating in the NPP cycle using the closed system of hydrogen combustion in the oxygen medium is considered in terms of efficiency of generating peak power at the main steam-turbine unit. This system allows to exclude hydrogen from entering the main NPP steam-power cycle, while unreacted oxygen circulates in the closed combustion system. The thermodynamic efficiency of the considered schemes of hydrogen steam superheating/overheating in the NPP cycle is determined.