Study on recovery and utilization of cold energy for insulation design of liquid hydrogen tanks

Insulation design is one of the key technologies for Liquid Hydrogen (LH 2 ) tanks. To enhance the insulation efficiency and energy utilization of the LH 2 , this study proposes a novel approach to enhance the insulation performance of LH 2 tank and cold energy cascade utilization of LH 2 . Three Cryo-cooling Insulation Systems (CIS) with various insulation schemes are designed, analyzed and compared from the perspectives of insulation performance, consumption and energy utilization efficiency. An optimal insulation scheme among three CISs is identified and evaluated. Additionally, a dimensionless number ( Ψ ) is proposed to assess the insulation advantages of the CISs. And the insulation performance and economic feasibility of the system be effectively balanced. The findings reveal that the insulation performance of the proposed CIS outperforms previous insulation methods by a factor of 239.13. Among the schemes in three CISs, Schemes 2 (Position of CSs at 6th, 25th and 35th layers), Schemes 3 (Position of CSs at 10th, 40th and 45th layers), and Schemes 3 (Position of CSs at 3rd, 40th and 45th layers) exhibit superior insulation performance in Cases #1 (CIS of LN2-LAr), Cases #2 (CIS of R14-R170), and Cases #3 (CIS of R1150-R23). Notably, Case #1 achieves the highest insulation performance, showing improvements of 2.58 and 1.63 times over Case #2 and Case #3, respectively. However, the energy output in Case #1 is approximately 248.12 W, constituting 83.10 % and 71.60 % of Case #2 and Case #3, respectively. Case #1 demonstrates the highest specific energy output, with improvements of 30.12 % and 81.05 % compared to Case #2 and Case #3, respectively. In terms of the exergy utilization rate of each equipment, the exergy utilization rate of equipment in Case #1 is the highest among the three cases. The study underscore the feasibility of cold energy utilization for insulation, providing solutions for energy conversion and thermal management of LH 2 tanks through cryo-cooling cascade utilization. • The performance of proposed insulation system improved by a factor of 239.13 compared to previous insulation methods. • The insulation performance of Case #1 exhibits an improvement of 2.58 and 1.63 times compared to Case #2 and Case #3. • The energy outputs of Case #1, Case #2 and Case #3 are 248.12 W, 298.58 W and 346.57 W. • The SEO value of Case #1 improves by 30.12 % and 81.05 % compared to Case #2 and Case #3.