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EAST超导托卡马克冷屏结构与受力分析 总被引:3,自引:2,他引:1
EAST是一个全超导磁体系统的托卡马克实验装置,超导纵场和极向场磁体工作在4K温区下。在磁
体和其它发热部件之间布置有冷屏系统,以减少作用到所有低温冷质部件上的热载,将其保持在最低水平。该系
统包括真空室冷屏(内冷屏)和外真空杜瓦冷屏(外冷屏)两部分。在分析了冷屏低温运行时所受热应力以及等离
子体破裂时所受电磁载荷的基础上,运用大型有限元分析程序NASTRAN,对其不同载荷状况进行了数值计算,为其
结构设计与优化提供了理论依据。 相似文献
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线圈终端盒(CTB)是保证ITER装置可靠运行的关键部件之一,为磁体系统与低温车间、电源大厅、数据采集系统和低温控制元件提供4.5K的超低温工作环境。线圈终端盒(CTB)内部设有80K冷屏,以吸收室温环境对其内部工作空间带来的辐射热负荷,在杜瓦和冷屏中间,设有30mm的真空多层绝热夹层。首先采用量热法和称重法,对多层绝热试件进行了热性能测试,然后分别与理论分析和CTB原型件系统实验结果进行对比,得出了CTB盒中多层绝热结构的热性能参数,为下一步大规模生产提供了有力的技术支持。 相似文献
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选择304LN 不锈钢作为冷屏的制作材料,将杜瓦冷屏分为16 个扇区,每个扇区由20 个子部分组成,在每一个子部分上布置相应的冷却管。选择液氦作为冷却剂。为检验杜瓦冷屏结构是否符合设计要求,分析了杜瓦冷屏的传热方式以及冷却原理,利用FLUENT 软件对设计的冷屏结构进行了热分析,得到了杜瓦冷屏面板的温度分布情况以及冷却管道进出口压力差。结果表明,杜瓦冷屏面板温度和冷却管道进出口压力差在合理范围内,验证了冷却管道布局的合理性,为后续杜瓦冷屏的设计提供了重要参考。 相似文献
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根据高μ子源超导俘获线圈整体测试系统的要求,设计了μ子源超导俘获线圈测试杜瓦系统.包含液氦杜瓦、真空杜瓦及绝热冷屏,采用Solidworks软件对测试杜瓦系统进行3D建模.通过对绝热冷屏统进行了详细的传热学计算,绝热冷屏的可以满足μ子源超导俘获线圈测试过程的漏热需求;根据μ子源超导俘获线圈测试实际工况,对真空杜瓦和液氦杜瓦进行了Ansys有限元软件分析与校核,得到杜瓦详细的应力及变形结果,分析表明,测试杜瓦的设计较为合理,可以作为工程设计的理论计算依据 相似文献
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本文报道由液氦(~4Hc)获得1K级低温的减压降温装置技术及其热分析.实验结果已达到1.17 K.测量了实验杜瓦的轴向温度分布.已用于超流氦温度下复合材料导热系数的实验研究和氦λ点温度以下温度计的标定. 相似文献
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在传导冷却超导磁体系统中,超导磁体与系统其它部分的温度平衡过程是依靠固体间的热传导来实现热量传递的。由于超导磁体和冷屏等低温部件冷却条件的差异,将导致磁体内部各处和冷屏不同部位的温度分布不均匀。分析研究超导磁体系统的低温温度分布状况,对于低温系统的热设计和磁体的温度裕度设计具有重要意义。文中借助于ANSYS有限元分析软件,建立了一个大口径传导冷却超导磁体低温系统的稳态三维热分析模型,仿真了超导磁体和冷屏的空间温度场,得到了传导冷却超导磁体低温系统的热分布规律。该分析结果对于大口径传导冷却超导磁体的低温系统设计具有重要的参考价值。 相似文献
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Acceleration of heavy ions through the superconducting linear accelerator is achieved by superconducting resonators housed in the cryomodules operating at 4.2 K. In the cryomodule, radiation heat flow from the ambient to the 600 kg of cold mass at 4.2 K is thermally screened by the intermediate thermal shield made of copper. The six surfaces of 17 m2 total surface area of the box-shaped thermal shield are cooled in series by the forced flow of liquid nitrogen at 3.2 bar absolute pressure. The boiling temperature of liquid nitrogen at 3.2 bar is 90 K. The steady-state temperatures of the different surfaces of the thermal shield are in the range of 96–115 K at 21.25 L/h flow rate. The steady-state thermal profile of the different surfaces of the thermal shield has also been estimated for different flow rates using a simple analytical technique. The analytical thermal profile of the thermal shield has been correlated with the experimental measurement. 相似文献
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In this paper, the design and structure of a vacuum variable-temperature blackbody system were described, and the steady-state thermal analysis of a 3-D blackbody model was presented. Also, the thermal performance of the blackbody was evaluated using an infrared camera system. The blackbody system was constructed to operate under vacuum conditions (2.67 × 10−2 Pa) to reduce its temperature uncertainty, which can be caused by vapor condensation at low temperatures usually below 273.15 K. A heat sink and heat shield including a cold shield were embedded around the radiator to maintain the heat balance of the blackbody. A simplified 3-D model of the blackbody including a radiator, heat sink, heat shield, cold shield, and heat source was thermophysically evaluated by performing finite elements analysis using the extended Stefan–Boltzmann’s rule, and the infrared radiating performance of the developed system was analyzed using an infrared camera system. On the basis of the results of measurements and simulations, we expect that the suggested blackbody system can serve as a highly stable reference source for the calibration and measurement of infrared optical systems within operational temperature ranges. 相似文献
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《Solid State Communications》1987,64(3):327-328
The thermal expansion of the High Tc superconducting ceramic YBa2Cu3O7-δ has been measured from 50 K up to room temperature by means of a capacitance dilatometer. No detectable anomalous change in lenght is observed at the critical temperature Tc, within the resolution of our experimental set up: Δl/l = 5 10−8. This indicates a weak dependence of Tc on pressure, contrarily to the one measured on (LaBa)CuO lower Tc superconducting ceramics. The Debye temperature is also estimated. 相似文献
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K. Tanaka A. Odawara S. Bandou A. Nagata S. Nakayama K. Chinone A. Yasaka Y. Koike S. Iijima 《Physica C: Superconductivity and its Applications》2009,469(15-20):881-885
We have developed a Transition Edge Sensor (TES) – Energy Dispersive Spectroscopy (EDS) for Transmission Electron Microscope (TEM) based on a dilution refrigerator. The dilution refrigerator was cooled by liquid helium (L-He), which was supplied from an L-He container separated from the dilution refrigerator. We adopted the hybrid magnetic shields combining a permalloy shield and a NbTi/Nb/Cu superconducting shield to operate the TEM–TES system under a magnetic field of 200 mT. The permalloy shield was used to prevent the ambient magnetic field until the NbTi superconducting shield cooled from room temperature (RT) to 2 K. The critical magnetic field was 220 mT for the TES change from a superconducting state to a normal state. The SQUID – current vs. bias current curve, under the condition that the snout was inserted in the TEM, was equal to the curve of the snout that was out of the TEM. The C (0 0 2) planes could be observed at 120 kV under the condition the snout was inserted in the TEM. 相似文献
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V. R. Romanovskii 《Technical Physics》2017,62(4):560-568
The conditions of the occurrence and development of thermal instabilities in the composite superconductor with a continuously increasing current-voltage characteristic, which is described by the power equation, have been studied. The conditions for thermal stabilization have been analyzed in the general form using dimensionless variables that keep their invariance when varying. For the local temperature disturbance, the critical energies and velocities of its irreversible propagation have been calculated. It has been proved that composites superconductors can have stable states, when the ultimate currents can be higher or lower of the conventionally preset critical current of the composite. Furthermore, superconductivity destruction at supercritical currents takes place not in the form of a stepwise transition from the superconducting to normal state, but due to the formation of thermal and electric switching waves that propagate along the composite superconductor with a constant speed. The condition for full thermal stabilization has been formulated for the superconducting composites with a power current–voltage characteristic. The results of the numerical experiments have proved that the existing theory of thermal stabilization, which assumes a stepwise superconducting–normal transition, leads to the considerable limitation of the range of the stable currents, at which a superconducting state can be kept. 相似文献
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本文研制了一台可以用于低温超导磁体冷却的液氦温区分离型二级脉管制冷机.单独测试第一级最低达到了13.8K,是单级脉管制冷机最低制冷温度新纪录;在40K温度下具有55.9W制冷量,可望在高温超导磁体冷却方面获得广泛应用.使用单压缩机单旋转阀驱动二级脉管,二级最低温度达到了2.6K,在4.2K下有590mW制冷量,同时一级在36.7K有15W的制冷量,满足小型低温超导磁体冷却的要求. 相似文献