Tri-Loop design and thermoeconomic analysis for the high temperature gas cooled nuclear reactor coupling energy storage system

Abstract

Thermal energy storage is a proposed solution that enables nuclear power plants to adjust their output without altering power levels. This technology manages fluctuations in the power generation process by storing generated heat above demand levels until it is required to produce steam. Despite the initial investment needed for infrastructure construction, these costs are easily offset by the ultimate returns, especially when efficiency is improved to 85% to 90%. In the context of nuclear power plant applications, helium molten salt energy storage systems demonstrate significant potential as an innovative power generation configuration. In this study, three cycle systems—helium, molten salt, and water (steam)—were employed to investigate and optimize the performance of the system. A series of modeling and simulation processes were conducted using EBSILON software to explore the impact of various parameters (such as pressure, reheat stages, and temperature) on the thermal efficiency of the power plant under both design and off-design conditions. To further study the system's performance, a thermo-economic analysis method based on the second law of thermodynamics was adopted. A thermal-economic analysis model was established, and a fire use analysis was performed on key equipment under representative conditions. Through this approach, we identified the distribution of fire use losses within the system, with the steam generator being the primary contributor to fire use losses among the three systems. Through comprehensive analysis of the simulation results, we conclude that the system exhibits outstanding thermal-economic performance when high-pressure parameters are combined with high temperature. This insight is crucial for modeling and optimizing the construction of nuclear power plants in China, providing a more comprehensive understanding of factors influencing thermal efficiency and contributing to more informed decision-making for the design and operation of tri-generation nuclear power stations.