Liquid nitrogen storage and distribution system for 6.5-meter large thermal vacuum chamber-LTVC

Cryogenic systems have been playing a significant role in space simulation and thermal vacuum testing of satellite payloads and sub-systems. Usually liquid nitrogen (LN₂) is a preferred fluid for space simulation systems. This is due to its various favourable operating characteristics like-very low temperature to liquefaction, wide temperature range, inert nonreacting nature, large latent heat of evaporation, abundance, availability and low cost of usage. Space Applications Centre (SAC) has established a 6.5m diameter Large Thermal Vacuum Chamber-LTVC facility to cater to the need for integrated payload level thermal vacuum tests. One of the critical sub-systems is LN₂ storage and its distribution system. LN₂ (approx. 4,00,000 litres) is stored in storage tanks (1,34,000 litres each). The Liquid Nitrogen and GN₂ distribution system consist of vacuum jacketed SI cryogenic lines of different sizes (1/2” to 4” sized-approximately 2000m) which are spread across the facility, connecting various thermal and vacuum systems. This paper presents the system configuration, manufacturing/fabrication, testing of LN₂ storage and distribution systems.