Indian Journal of Cryogenics

The ITER Cryogenic system is essentially one of the most complex systems in the world. It consists of cryoplant (source of cold power), cryodistribution system (for distribution of cold power) and cryolines (for channeling of cold power). These cryolines are of about 5 km in length having complex geometry (considering bends, angles, branch connections, etc.) and stringent criteria for design. The ITER cryolines are presently under preliminary or final design phases except the nitrogen cryolines which are under manufacturing phase after successful completion of final design. These nitrogen cryolines have length of around 600 m with pipe in pipe geometry and diameters of process pipes (PP) ranging from DN 15 to DN 250 with outer vacuum jacket ranging from DN50 to DN400. The sizing of these nitrogen cryolines has been optimized based on the specified pressure drop limit. In order to meet the specification of heat load as 2 W/m, the design of internal components such as internal sliding spacers, fix spacers has been performed and layers of multi-layer insulation (MLI) have been estimated accordingly. The paper describes the major input data, constraints for design of nitrogen cryolines, their design & analysis approach and result.