Thermo-Hydraulic Design of the First Wall of the DTT Facility

The main mission of the divertor tokamak test (DTT) facility is to study advanced solutions for the power exhaust issue in view of a fusion power plant. In this respect, a significant amount of heat is expected to be absorbed by the first wall (FW) during operation. Therefore, the DTT FW is designed to be an actively water-cooled system. A proper hydraulic model is needed for the development of a cooling architecture of the system able to fulfill the requirements of operational safety under thermal loads and compliance with the DTT plant specifications. The present study aims to address this challenge, offering practical inputs for further optimization. Based on the existing conceptual design, the cooling circuits have been setup inside the plasma-facing components (PFCs). In this phase, empirical equations and hydraulic simulations have been adopted to investigate the hydraulic behavior of the modules that make up the FW and to evaluate the main design parameters, namely, velocity and pressure drops in the cooling channels. The outcome of such analysis demonstrated that the current design of the FW system complies with the imposed requirements. Moreover, operating flexibility has been demonstrated by identifying a proper range of the mass flow rate for each subsystem. Therefore, the models implemented in this study and the obtained findings prove to be suitable to support the next activities of engineering design of the FW.