The Iter Shield Block Thermal Fluid And Thermal Stress Calculation

ITER (International Thermonuclear Experimental Reactor) is currently the largest tokamak experimental device under construction in the world, the purpose is to verify the technical and engineering feasibility of controlled thermonuclear, and provide a theoretical foundation and experimental guidance for future commercial application. The operation in ITER fusion reactions produce large amounts of energy, which is in the form of 14MeV neutrons, and the energy of these neutrons is converted to shield blankets by collision with the shield blankets facing plasma. In addition, most of the energy is transported through water cooling system out of ITER device in process. Therefore, an important requirement of the design for shield blankets is to ensure that the cooling capacity is good enough to take away enough energy. The shield blanket consists of first wall and shield block, of which bear the main energy transport work is shield block, the cooling capacity of shield block affects the cooling effect of shield blanket. In addition, good design of the cooling channels can decrease the local resistance coefficient of the fluid and the fluid velocity distribution, which make the temperature of shield block a small range of change, and the homogeneous distribution of the temperature could reduce the thermal stress and deformation caused by the uneven heat distribution. Based on these requirements, thermal analysis and fluid analysis of shield blocks are particularly important to provide the reliability and validity of verification results and guidelines for the design of the shield blocks.Firstly, this article calculates temperature field and flow field of the fourth shield block (BM04) and the eighth shield block (BM08) design models using universal computational fluid dynamics software ANSYS CFX, and calculates thermal structural coupled field in the ANSYS Workbench using the temperature distribution in previous calculation, thermal stress distribution of the two shielding blocks are obtained, the results is analyzed, they are feasible and safe to meet the ITER requirements. Secondly, the calculation of the two shielding blocks results were compared to found that heat releasing capacity of BM08 cooling pipes are much poorer than BM04, leading to the results of preliminary analysis is the irregular structure of BM08, which can not be designed as radius cooling pipes in BM04. Meanwhile, parallel cooling pipes can not take away enough heat that a thermal deposition zone is formed on the back of BM08. Finally, the cooling pipes structure in the model of the design is analyzed to found that the bottom of the radial tube in BM04 design structure can hardly be achieved in engineering fabrication, and the velocitys of cooling pipes are not well-distributed in BM08, these areas in the designs are pointed out for improvement and some improving suggestions are put forward.