Numerical Simulation Of Quench Propagation Characteristics For Bi-Based High-Temperature Superconducting Tapes

With the large number of superconducting magnets in the many modern high-technology equipment and engineering applications,the safety of superconducting magnet structures are getten more and more attention. Superconducting magnet systems and devices in practical applications work in complex and multi-field environment,which include the ultra-low temperature and high current-magnetic field, the quench and quench propagation characteristics of them in multi-field environment is directly related to their health, safty and stable operation and evaluation.Firstly, the review on quench of superconducting materials and structures is introduced.Based on the heat conduction equation, the quench and quench propagation velocity for idealized superconductor under adiabatic conditions is derived theoretically, and the reasons for the differences between high-temperature superconducting materials and low-temperature superconducting materials in the quench mechanism and quench propagation velocity are discussed. Secondly, using a thermoelectric coupling quench analysis model and considering the thermal, electrical parameters’nonlinear dependence on temperature for high-temperature superconducting composite tape, a finite element simulation of the the localised thermal quench for Bi-2223/Ag high-temperature superconducting composite tapes is carried outThe temporal and spatial variation of temperature for superconducting tapes during the quench process is obtained. And the influence of transport current, trigger temperature, operating temperature and other factors on the quench propagation characteristics for superconductor is discussed in detail.In the end, an thermo-electric-elastic coupling quench model is established by introducing the effect of strain on the critical current density. The quench process of Bi-2223/Ag high-temperature superconducting composite tapes is simulated.The simulation results show the strain distribution of time and space for superconducting tapes during quench process and the quench propagation velocities, and also further analyse the influence of strain on the quench propagation velocity or quench propagation process.The results of this study are expected to have some guiding significance and reference value for the design and manufacture of superconducting materials and magnets, the stability of superconducting magnets and the design of quench protection system.