Wendelstein 7-X is the world’s largest nuclear fusion experiment of stellarator type, in which a hydrogen plasma is confined by a magnet field generated with external superconducting coils, allowing the plasma to be heated up to fusion temperature. The water-cooled Plasma Facing Components (PFC) protect the Plasma Vessel (PV) against radiative and convective heat from the plasma. After the assembly process of heat shields and baffles, several cracks were found in the braze and cooling pipes. Due to heat loads occurring during each Operational Phase (OP), thermal-stresses are generated in the heat sinks, brazes and cooling pipes, capable to drive cyclic crack-growth and, eventually, a water leak through the pipe wall. The aim of this study is to predict the operational limits of the baffles and heat shields, by using numerical models based on FEM-DBEM approach in order to obtain a prediction of the number of tolerable load cycles.
FEM-DBEM Coupled Procedure To Analyse Crack Scenarios In A Baffle Cooling Pipe
CITARELLA, Roberto Guglielmo;GIANNELLA, VENANZIO;LEPORE, MARCELLO ANTONIO;
2016-01-01
Abstract
Wendelstein 7-X is the world’s largest nuclear fusion experiment of stellarator type, in which a hydrogen plasma is confined by a magnet field generated with external superconducting coils, allowing the plasma to be heated up to fusion temperature. The water-cooled Plasma Facing Components (PFC) protect the Plasma Vessel (PV) against radiative and convective heat from the plasma. After the assembly process of heat shields and baffles, several cracks were found in the braze and cooling pipes. Due to heat loads occurring during each Operational Phase (OP), thermal-stresses are generated in the heat sinks, brazes and cooling pipes, capable to drive cyclic crack-growth and, eventually, a water leak through the pipe wall. The aim of this study is to predict the operational limits of the baffles and heat shields, by using numerical models based on FEM-DBEM approach in order to obtain a prediction of the number of tolerable load cycles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
