摘要
针对液氢贮箱建立了考虑仲-正氢催化转化(P-O)的变密度多层绝热/蒸气冷却屏(VDMLI/VCS)二维传热模型,详细分析VCS内氢气温度梯度对绝热系统的影响,从绝热性能和附加质量的角度对比VDMLI、VDMLI+单蒸气冷却屏(SVCS)、VDMLI+双蒸气冷却屏(DVCS)、VDMLI+SVCS+P-O和VDMLI+DVCS+P-O这5种绝热方案的综合性能.结果表明:SVCS的最佳布置区间为VDMLI厚度的42％～58％,DVCS内、外屏的最佳布置区间分别为VDMLI厚度的12％～28％和55％～72％;增加SVCS和DVCS结构,较VDMLI漏热热通量分别降低69.91％和74.50％,附加质量分别增加68.98％和137.97％;引入仲-正转化后,SVCS的最佳布置区间更靠近冷端,DVCS的最佳布置区间变化较小;仲-正转化的加入提高了绝热性能且附加质量增加极小,因此无仲-正转化的绝热方案不具有性能优势.短期、中期、长期在轨任务分别推荐采用VDMLI、VDMLI/SVCS/P-O、VDMLI/DVCS/P-O绝热方案.
Abstract
A two-dimensional heat transfer model was established for the variable density multi-layer insulation(VDMLI)with vapor-cooled shield(VCS)and catalytic conversion of para-ortho hydrogen(P-O)of the liquid hydrogen tank.The influence of the hydrogen temperature gradient in VCS on the thermal insulation system was analyzed in detail.The comprehensive performances of VDMLI,VDMLI+single vapor-cooled shield(SVCS),VDMLI+double vapor-cooled shield(DVCS),VDMLI+SVCS+P-O,and VDMLI+DVCS+P-O were compared from the perspectives of thermal insulation performance and additional mass.The results show that the optimal layout interval of SVCS is 42％-58％of VDMLI thickness,and the optimal layout intervals of DVCS's inner and outer shield are 12％-28％and 55％-72％of VDMLI thickness,respectively.Compared with VDMLI,the application of SVCS and DVCS reduces the heat flux by 69.91％and 74.50％,and increases the additional mass by 68.98％and 137.97％,respectively.After the introduction of para-ortho hydrogen conversion,the optimal layout range of SVCS is closer to the cold end,and the optimal layout range of DVCS changes less.The addition of para-ortho hydrogen conversion improves the insulation performance and the additional mass increases very little,so the insulation scheme without para-ortho hydrogen conversion does not have performance advantages.Comparing the performance of different adiabatic schemes,the VDMLI adiabatic scheme is recommended for short-term on-orbit missions,the VDMLI/SVCS/P-O adiabatic scheme is advised for medium-term on-orbit missions,and the VDMLI/DVCS/P-O adiabatic scheme can be adopted for long-term on-orbit missions.
维普
万方数据