Abstract

Rapid transfer of large cryogenic models between ambient and cryogenic environments causes severe thermal shocks to the dry air system, threatening dew-point stability and equipment safety. Using CFD, this study builds a 1:1 model of a cryogenic transport isolation system, including the dry hall, model carrier, temperature-conditioning room, and test section plenum. Three scenarios are analyzed: static suspension, descent to the temperature-conditioning room, and descent to the test section plenum. The effects of descent speed (1.2 vs. 2.5 m/min) and makeup air flow (0–12,500 m3/h) on temperature distribution and cable safety are examined. Results show that after 10 min of static suspension, the carrier interior averages 192 K with strong stratification and a minimum of 170 K. During descent, higher speed and larger air flow improve thermal retention. At 2.5 m/min and 10,000 m3/h, cable-adjacent gas stays above −60 °C. For the plenum, descent-matched displacement ventilation (e.g., 6000 m3/h for 1.2 m/min) keeps both the cable and the plug-in unit safe. Including the cable thermal capacity gives a smaller actual temperature drop than conservative gas-temperature estimates. This work provides numerical guidance for dry system design, operation optimization, and cryogenic protection during rapid model transfer.

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