August 14, 2025Open Access

Thermodynamic Modeling of Multilayer Insulation Schemes Coupling Liquid Nitrogen Cooled Shield and Vapour Hydrogen Cooled Shield for LH2 Tank

JLJingyang LuTianjin University LCLiqiong ChenSouthwest Petroleum University XZXingyu ZhouHangzhou Dianzi University

Key Points

The MLI-LNCS scheme achieved an 88.09% reduction in heat leakage, revealing significant insulation performance improvements.
Optimal configurations for MLI-LNCS included 36 inner multilayer insulation layers positioned at 49% of the tank.
Thermodynamic models were developed to analyze insulation schemes, incorporating boundary conditions to predict temperature effects.
The findings indicate a trade-off between heat leakage reduction and increased system complexity and operational costs.

Abstract

The thermal insulation performance of liquid hydrogen (LH2) storage tanks is critical for long-distance transportation. The active cooled shield (ACS) technologies, such as the liquid nitrogen cooled shield (LNCS) and the vapor hydrogen cooled shield (VHVCS) are important thermal insulation methods. Many researchers installed the VHVCS inside the multilayer insulation (MLI) and obtained the optimal position. However, the MLI layer is often thinner than the vacuum interlayer between the inner and outer tanks, and there is a large vacuum interlayer between the outermost side of MLI and the inner wall of the outer tank. It is unknown whether the insulation performance can be improved if we install ACS in the mentioned vacuum interlayer and separate a portion of the MLI to be installed on the outer surface of ACS. In this configuration, the number of inner MLI (IMLI) layers and the ACS position are interdependent, a coupling that has not been thoroughly investigated. Therefore, thermodynamic models for MLI, MLI-LNCS, and MLI-VHVCS schemes were developed based on the Layer-by-Layer method. By applying Robin boundary conditions, the temperature distribution and heat leakage of the MLI scheme were predicted. Considering the coupled effects of IMLI layer count and ACS position, a co-optimization strategy was adopted, based on an alternating iterative search algorithm. The results indicate that for the MLI-LNCS scheme, the optimal number of IMLI layers and LNCS position are 36 layers and 49%, respectively. For the MLI-VHVCS scheme, the optimal values are 21 layers and 39%, respectively. Compared to conventional MLI, the MLI-LNCS scheme achieves an 88.09% reduction in heat leakage. However, this improvement involves increased system complexity and higher operational costs from LN2 circulation. In contrast, the MLI-VHVCS scheme achieves a 62.74% reduction in heat leakage, demonstrating that using sensible heat from cryogenic vapor can significantly improve the thermal insulation performance of LH2 storage tanks. The work of this paper provides a reference for the design and optimization of the insulation scheme of LH2 storage tanks.

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