20 K급 액화수소 모사 조건에서 3종 밸브의 기밀 성능 및 긴급차단밸브 작동 검증

초록

Liquefied hydrogen (LH2) service near 20 K imposes severe sealing requirements on valves, while conventional cryogenic valve standards are generally limited to temperatures down to approximately 77 K. This study applies a previously developed cryogen-free test methodology to three valve types: an emergency shut-off valve, a manual valve, and a check valve. A vacuum-insulated test system using Gifford-McMahon cryocoolers, copper conduction blocks, temperature sensors, helium gas, and a helium mass-spectrometer leak detector was used to reproduce 20 K-class conditions without direct liquid-hydrogen handling. Each valve was evaluated under ambient and 20 K-class conditions for shell and seat leakage, while an operation test was additionally performed for the emergency shut-off valve. Leakage performance was assessed using leakage acceptance criteria adopted from ISO 28921-1:2022. All three valve types satisfied the adopted leakage criteria under both ambient and 20 K-class conditions, and the emergency shut-off valve maintained normal operation under 20 K-class conditions. These results demonstrate the applicability of the cryogen-free 20 K-class test method to the three tested 2-inch valve types.

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