Influence Analysis of Number and Density for Radiation Shields on Leakage Heat of Superconducting Cavity Vertical Test Dewar

doi:10.7538/yzk.2018.youxian.0741

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	Influence Analysis of Number and Density for Radiation Shields on Leakage Heat of Superconducting Cavity Vertical Test Dewar
	Jin, Shufeng 2; Chen, Shuping 2; Zhang, Junhui 1; Su, Hailin 1
刊名	Yuanzineng Kexue Jishu/Atomic Energy Science and Technology
	2019-04-20
卷号	53 期号:4 页码:754-760
关键词	Cavity resonators Dewars Experiments Gas generators Heat conduction Heat flux Helium Liquefied gases Radiation shielding Superfluid helium Temperature Thermal insulation Heat transfer model High vacuum multilayer insulations Insulation performance Liquid helium Numerical calculation Radiation heat flux Superconducting cavities Variable density
ISSN号	10006931
DOI	10.7538/yzk.2018.youxian.0741
英文摘要	The superconducting cavity vertical test Dewar is a liquid helium open vessel, which has high requirement for thermal insulation performance. The inner vessel of the Dewar is insulated with high-vacuum multilayer insulation, and the top cover side is multi-screen insulation. In order to reduce the leakage heat on the top cover side of the Dewar, a variable density radiation shield method was proposed. The coupling heat transfer model of heat conduction, convection and radiation was established for the cover, radiation shield, liquid surface and helium gas, and was verified by experiment. The influence of the number of radiation shield on the leakage heat and the optimal radiation shield density were obtained by numerical calculation. The result shows that the calculated result of the radiation shield temperature is consistent with the experimental result, with an average relative deviation of 8.37%, and the heat transfer model is considered to be reasonable. The Grashof number (Gr) of the helium gas between the first radiation shield (shield 1) near the liquid surface and the liquid surface has a maximum value (T1=9.14 K, Gr=1.12×1014) with the increase of temperature T1 of shield 1, and after T1 exceeds 35 K, Gr remains basically unchanged. When the radiation shield is arranged at equal space, the total leakage heat change is not obvious after the number of radiation shield is greater than 11. Under certain number of radiation shield, the gas heat conduction between two adjacent shields is dominant, and the heat conduction transfer decreases and the radiation heat flux increases from the low temperature area close to the liquid surface to the high temperature area near the cover. As the number of radiation shield is 11, the method of the variable density radiation shield, which is to be arranged for 7 radiation shields in the high temperature area and 4 radiation shields in the low temperature area, has minimal leakage heat. The method can reduce the heat leakage by 4% compared with the equal space method. © 2019, Editorial Dept. of JA. All right reserved.
语种	中文
出版者	Atomic Energy Press
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/114226]
专题	石油化工学院
作者单位	1.Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou; 730000, China 2.College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou; 730050, China;
推荐引用方式 GB/T 7714	Jin, Shufeng,Chen, Shuping,Zhang, Junhui,et al. Influence Analysis of Number and Density for Radiation Shields on Leakage Heat of Superconducting Cavity Vertical Test Dewar[J]. Yuanzineng Kexue Jishu/Atomic Energy Science and Technology,2019,53(4):754-760.
APA	Jin, Shufeng,Chen, Shuping,Zhang, Junhui,&Su, Hailin.(2019).Influence Analysis of Number and Density for Radiation Shields on Leakage Heat of Superconducting Cavity Vertical Test Dewar.Yuanzineng Kexue Jishu/Atomic Energy Science and Technology,53(4),754-760.
MLA	Jin, Shufeng,et al."Influence Analysis of Number and Density for Radiation Shields on Leakage Heat of Superconducting Cavity Vertical Test Dewar".Yuanzineng Kexue Jishu/Atomic Energy Science and Technology 53.4(2019):754-760.