Thermal Desktop을 활용한 수소 해석 사례 소개4

사례4: 액화수소 탱크

• 수소물성: parahydrogen
• 외부온도: 293.15K, 자연대류
• 단열: 진공단열 & MLI
• 내부탱크부피: 1.8325 m3
• 초기 Fill level: 0.5 meter (체적의 50%채워진 상태)
• Well mixed modeling (case1) 방식과 Liquid core 분리 방식(case2)의 모델링을 비교

Thermal/Fluid Network 해석의 Basic Concept

Model Considerations

• Multiple or singular lumps in the liquid and vapor regions of the Tank
• Real gases (also mixtures) and compressible liquids
• Venting, pressurizing, and draining
• Condensation and evaporation/boiling
• Wall heat transfer
• Elliptical, cylindrical, and spherical tank geometries

First Order Stratification Modeling

• Ullage : nearly completely stagnant
• Liquid : slow recirculation with isolated core

- Isolated most (85~95%) of liquid in “blocked” core

- Recirculate between side/top and core liquid volumes based on boundary layer heat transfer

• Can include fill, drain, pressurize and vent
• Only useful for short term holds

Refined Stratification Modeling

• More detail in the liquid core

- For improved prediction of extracted liquid temperatures

- Allows longer term holds

• Uses a flat-front (FF) Pipe to model the core liquid

- Requires more detailed recirculation calculation

• More difficult to apply in spherical or horizontal tanks
• Core isolation fraction is still a key uncertainty