Technical and economic optimization of the hydrogen-thermal energy storage at nuclear power plant

The article discusses and optimizes the system developed by the authors based on closed-cycle hydrogen-thermal storage using external and built-in hydrogen-oxygen steam generator. On the basis of the finite element method with the use of the ANSYS software package, the process of starting up and entering the operating mode of the steam generator was simulated. The distribution dynamics of temperature fields and thermomechanical stresses in the walls of the combustion chamber are shown. When using the built-in combustion chamber, the maximum wall temperature after reaching the operating mode was 391°C and for 179°C for the external combustion chamber. The distribution dynamics of thermomechanical stresses fields practically corresponds to the distribution dynamics of temperature fields. In this case, the thermomechanical stresses for the built-in combustion chamber amounted to 219MPa, for the external – 195MPa. Taking into account the estimation of the calculated lifetime, an optimization technical and economic analysis of the efficiency implementation of hydrogen-oxygen steam generator was carried out. The use of built-in hydrogen-oxygen steam generator makes it possible to increase the efficiency of off-peak electricity use by 14.76% and to reduce the cost of peak electricity production by 18.4%, taking into account the lifetime.