Numerical Analysis of a Pyro-breaker Utilized in Superconducting Fusion Facility

Pyro-breaker is a fast-responding and high-reliable explosive-driven circuit breaker, which has been applied in several quench protection systems, such as ITER and Experimental Advanced Superconducting Tokamak (EAST). The choice of the detonator and the dosage of the explosive is a significant part of the development of a new pyro-breaker. The presented pyro-breaker has two units, both driven by explosives, but the specific driving structures are different from each other. The numerical modeling of these two units includes the coupling of multiple materials, and the model is complex due to the cooperative action of each other. The numerical models of the explosion on the conductors are built respectively for the two units, and the simulation is carried out in ANSYS / LS-DYNA. The conductor structure, explosive dosage, and driving mechanism are checked and calculated. Based on the results of numerical simulation, several explosion tests were conducted to verify the accuracy of the model. The breaking processes of the conductors under different dosages and shaped explosives were analyzed. The mechanical structure of the conductor was optimized and the forming problem after the explosion was solved. The model will be the theoretical basis for the designing of the pyro-breaker in the quench protection system of China Fusion Engineering Experimental Reactor (CFETR).