Multi-field coupled effect of thermal disturbance on quench and recovery characteristic along the hybrid energy pipe

In a novel high temperature superconducting (HTS) hybrid energy pipe, the liquefied natural gas (LNG) and electricity are transported together along the energy pipeline to attain high energy transmission efficiency. When the pipe is exposed to thermal disturbance, the protective medium, liquid nitrogen (LN₂), can restrain the quench phenomenon by boiling heat transfer. In order to analyze the multi-field coupled effects of thermal disturbance on the quench and recovery process of the hybrid energy pipe, a one-dimensional quench model is originally proposed in this paper. The model can reflect the intricate interaction of fluid dynamics, boiling heat transfer and current sharing. The results indicate that the high temperature region moves towards the upstream direction in the recovery process. There are three different characteristics: thermal stable zone, quench controllable zone and quench propagation zone. The critical quench energy Q_qc is 18% of the critical recovery energy Q_rc and the critical quench distance l_qc is 9 times as long as the critical recovery distance l_rc, independent of the operation conditions. The Q_qc and l_qc will results in the longest recovery process of the pipe. The pulse duration hardly affects the quench and recovery characteristics. The critical equilibrium current I_ec is a constant value of 1800 A, independent of the heat pulse parameters. The I_ec will cause the infinite recovery time, which is harmful for the hybrid energy pipe. These rules are significant for the stable operation and design of the hybrid energy pipe. The proposed model can reflect the multi-field strong coupled effect of the thermal disturbance on the quench of system, which fulfils the fast prediction of the quench and recovery behavior.