Thermal evaluation of different integration schemes for solar-nuclear hybrid systems

Abstract

Solar-nuclear hybrid systems have been proposed to meet the growing energy demand and mitigate the effects of global warming caused by fossil fuels. To achieve optimal design for these systems, an appropriate integration scheme is crucial. This article proposes three integration schemes to couple the solar system with the nuclear power plant and evaluates their performance based on energy and exergy evaluations. A reference design of the hybrid system is used, consisting of a 77.04 MWth solar tower system coupled with a 330 MWth System-Integrated Modular Advanced Reactor. Numerical results show that heating partial feedwater and saturated steam with solar energy is the best-integrated scheme, resulting in the maximum thermal efficiency and exergy efficiency for the solar-nuclear hybrid system. Comparing the standalone reactor power system to the solar-nuclear hybrid system reveals that using solar energy to heat the feedwater and saturated steam can greatly improve the energy efficiency of the power plant, increasing it to 34.97%. The solar heat to nuclear heat ratio is 25.01%, while the solar power to nuclear power ratio is as high as 44.42%, indicating effective utilization of solar heat contribution. Exergy loss distributions of the solar-nuclear hybrid system reveal that exergy losses mainly occur within the nuclear reactor and solar field, taking possession of 70% of all exergy losses.