Comparison of CFETR nuclear fusion power plant thermal storage technology

Abstract

BackgroundDue to its pollution-free nature and non consumption of fossil fuels, nuclear fusion is the most ideal future energy source. China is preparing to build a China Fusion Engineering Test Reactor (CFETR) with independent intellectual property rights, and plans to build a commercial thermonuclear fusion power plant that can generate electricity externally by the mid-20th century. However, there is contradiction between the instability of nuclear fusion heating power output and the smooth operation of steam turbine generators, hence thermal storage technology is used for peak shaving and valley smoothing of power output in nuclear fusion reactors.PurposeThis study aims to compare heat storage technologies applied to CFETR nuclear fusion power plants to reduce its the peak and valley power output.MethodsThe parameters of helium cooled ceramic breeder cladding in nuclear fusion reactors was selected as the boundary conditions for thermal storage technology. By evaluated the applicable temperature range of thermal storage technology, three potential thermal storage technologies, i.e., chemical heat storage, sensible heat storage technology and phase change heat storage, for CFETR nuclear fusion power plants were preliminarily analyzed, and their costs were preliminarily predicted.ResultsThe three major types of heat storage technologies can all select heat storage media suitable for the temperature parameters of the helium cooled breeder blanket in CFETR nuclear fusion power plants. However, chemical heat storage has the potential to be applied in CFETR nuclear fusion power plants due to the temperature difference between its heat absorption and release, which is not conducive to the stability of the system and causes energy loss. Sensible heat storage technology and phase change heat storage technology have smaller temperature differences between their heat absorption and release. The preliminary economic analysis results show that the cost of phase change heat storage is the lowest, followed by molten salt heat storage, and the use of silicon bricks as the heat storage medium in solid-phase sensible heat storage technology. The use of cast steel as the heat storage medium in solid-phase sensible heat storage technology has the highest cost.ConclusionIn thermal storage technology, molten salt thermal storage technology has a high degree of maturity and has a large number of engineering applications, with a cost between phase change thermal storage and solid-phase sensible thermal storage, and has great potential for application. The cost of phase change heat storage is the lowest, and the parameters are suitable for nuclear fusion power generation. However, its technological maturity is relatively low, and it is expected to become a focus of future research.

Keywords

• nuclear fusion
• cfetr
• power generation technology
• energy storage
• heat storage
• economic analysis