Design analysis and manufacturing of the cooling lines of the in vessel components of WENDELSTEIN 7-X

All in vessel components (IVCs) of W7-X are actively cooled. Inside the plasma vessel about 4 km of pipes will be installed, supplying water to the IVC. 226 cooling circuits with 78 variants are necessary. The cooling circuits enter the cryostat and the plasma vessel through ad hoc flanged penetrations called “plug-ins”, which provide for the vacuum boundary between the plasma chamber and the torus hall atmosphere. The plug-ins are installed inside the W7-X ports. Some of the plug-ins are also used for the diagnostic cables. In total eighty plug-ins will be produced and installed. The inlet/outlet cooling lines are connected to the plug-ins using a welded hydraulic connector. The layout of the cooling lines is rather complex in consideration of the limited space and the routing between many component parts. Additionally the differential thermal expansion of the lines with respect to the supporting structures during the different operation scenarios had to be compensated by ad hoc supports and adjustments in the flexibility of the lines.