80 K Liquid Nitrogen (LN2) Booster System for SST-1

The 80 K thermal shields (double embossed type) in the Steady State Superconducting Tokamak (SST-1) at Institute for Plasma Research (IPR) are envisaged to be cooled to maintain a temperature uniformity of +/- 5 K against the heat load of 20 kW using forced flow single-phase liquid nitrogen at 6 bar (g), 80 K for a designated nominal flow of ∼1 kg s-1. Single phase forced flow sub-cooled LN₂ has been adopted to avoid uneven hydraulic distribution, pressure fluctuations, thermal runaway and vapor locking etc. The 80 K booster system consists of booster pumps, sub-cooler vessel, interconnecting vacuum jacket cryo lines and dummy load along with its ancillary components in a compact skid of 2.3 m (L) × 2.3 m (B) × 6 m (H). This paper describes the conceptual design, process flow diagram (PFD) along with process and instrumentation diagram (P & ID) of the 80 K booster system.