CFETR核聚变发电厂储热技术对比

Comparison of CFETR nuclear fusion power plant thermal storage technology

为解决核聚变发电热功率输出不稳定性和汽轮发电机组平稳运行之间的矛盾,中国聚变工程实验堆(China Fusion Engineering Test Reactor,CFETR)核聚变发电厂可运用储热技术对核聚变堆的功率输出进行削峰平谷。储热技术有多种类型,各类储热技术对于核聚变发电厂的适用性亟须进行对比。本文选取核聚变反应堆氦冷陶瓷增殖包层的参数作为储热技术边界条件,通过对储热技术适用温度范围进行评估,初步分析出有潜力运用于CFETR核聚变发电厂的三种储热技术,并对其进行成本初步预测。三大类储热技术均可选出适用CFETR核聚变发电厂氦冷增殖包层温度参数的储热介质。但化学储热由于其吸热和放热存在温差,不利于系统的稳定性及造成能量的损耗,显热储热技术和相变储热技术吸热温度和放热温度温差较小,具有应用于CFETR核聚变发电厂的潜力。初步经济性分析结果显示:相变储热成本最低,其次为熔融盐储热,再次为固相显热储热技术中利用硅砖作为储热介质,固相显热储热技术中利用铸钢作为储热介质成本最高。储热技术中,熔融盐储热技术、相变储热技术、固相显热储热具有应用于核聚变发电厂氦冷增殖包层的先决条件。熔融盐储热技术成熟度较高,有大量工程应用,造价在相变储热和固相显热储热之间,运用潜力较大。相变储热的成本最低,参数适用于核聚变发电,但其技术成熟度较低,有望成为未来研究的重点。

[Background]Due 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.[Purpose]This study aims to compare heat storage technologies applied to CFETR nuclear fusion power plants to reduce its the peak and valley power output.[Methods]The 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.[Results]The 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.[Conclusion]In 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.