多层材料/气冷屏传热二维模型与绝热性能

Two-dimensional modeling and thermal insulation performance of multilayer insulation/vapor-cooled shield

为更加准确地指导低温贮箱多层绝热(VD-MLI)/气冷屏(VCS)复合绝热结构的设计,建立了VD-MLI/VCS二维模型.考虑了VCS内蒸气升温对绝热性能空间分布的影响,并就传统一维模型和新建二维模型的预测能力与复合绝热结构的传热规律开展了对比分析.结果显示:VCS布置于VD-MLI第16层时漏热热流最小,为0.11 W/m^(2),最小漏热处一维模型对贮箱漏热量产生9%的低估;沿氢气流动方向贮箱漏热热流从0.02 W/m^(2)升高至0.23 W/m^(2),VCS冷却效果逐渐减弱.VD-MLI/VCS绝热结构的温度场随VCS的位置改变呈现不同形式的二维分布,造成贮箱各处绝热性能不一致,建议在VD-MLI总厚度的26.7%~68.3%内布置VCS.

To provide more accurate guidance for the design of multi-layer insulation(VD-MLI)/vapor-cooled shield(VCS)composite insulation structures of cryogenic storage tanks,a two-dimensional VD-MLI/VCS model was established,focusing on the influence of temperature rise of the cryogenic gas in VCS on the spatial distribution of insulation performance.A comparative analysis was conducted on the predictive ability of traditional one-dimensional model and newly constructed two-dimensional model,as well as the heat transfer law of composite insulation structures.The results show that the heat leak reaches the minimum value when VCS is arranged at 16th layer of VD-MLI,which is 0.11 W/m^(2).The one-dimensional model underestimates the heat leak of the storage tank by 9%.The cooling effect of VCS gradually weakens since the heat leak of the storage tank increases from 0.02 W/m^(2) to 0.23 W/m^(2) along the flow direction of hydrogen.The temperature field of VD-MLI/VCS insulation structure exhibits different patterns of two-dimensional distribution as the position of VCS changes,resulting in inconsistent insulation performance in various parts of the storage tank.It is recommended to arrange VCS within the range of 26.7%to 68.3%of the total thickness of VD-MLI.