Strategy and methods on thermal integrity management of the ITER Thermal Shield

This paper aims to provide a comprehensiveness description of the ITER Thermal Shield thermal integrity management keeping focused on the methods required for supporting the Thermal Shield manufacturing and assembly phases. Three main aspects are covered: 1) accurate heat load estimation into the Thermal Shield; 2) thermo-hydraulic flow modelling; 3) combined analytical-experimental method for sizing pipe orifices. The Thermal Shield heat loads estimation has to be accurate in order to know the margins regarding the agreed limits with the Cryoplant and Magnets. The proposed methodology results on a better understanding of the level of conservatism of the estimated heat inputs into the Thermal Shield. A detailed analysis of the coolant temperature rise on the cooling tubes is also described in combination with experimental data and fluid-dynamic analysis of the required pipe orifices. As a result, a pipe orifices sizing method is described and it is assessed the convenience of introducing thermo-hydraulic considerations into the flow analysis. As conclusion the paper presents the whole strategy as a powerful tool for properly assessing the impact of the silver coating quality (during manufacturing and assembly) as well as the impact of the final design of the interfacing systems and the actual final flow.