EAST阻性换热器多物理场耦合模拟计算

Multi-physics Coupling Simulation of Resistive Heat Exchanger in EAST

阻性换热器是EAST高温超导(HTS)电流引线的重要组成部分,目前有三头螺旋翅片和叠片两种结构形式,为了比较这两种阻性换热器的优劣,对它们的热工水力性能进行了多物理场耦合模拟计算,计算结果表明:两种阻性换热器在换热性能方面基本相当,均可满足快速换热的要求,但叠片换热器的流动阻力远小于三头螺旋翅片换热器的。实际运行过程中,三头螺旋翅片换热器中氮冷却回路的压力控制较为困难,经常需人工调节控制阀阀门,而叠片换热器中氮冷却回路的压力控制则较为简单,不需经常调节。因此,叠片式结构较三头螺旋翅片式结构更适合应用在EAST阻性换热器中。

Two types of resistive heat exchangers which are cooled with nitrogen vapor are designed for the HTS current leads in EAST.The study of the thermal-hydraulic performance with multi-physics coupling simulation for the two types of resistive heat exchangers was presented in this paper.The simulation results show that the two resistive heat exchangers are almost the same in heat transfer performance,but the foil stack heat exchanger is much better than three-helical fin heat exchanger in flow performance with a low flow resistance.Considering the large pressure drop of nitrogen vapor in the three-helical fin heat exchanger,which can cause troubles for the control of pressure in the nitrogen cooling loop,the foil stack is a better choice than three-helical fin for the resistive heat exchanger in EAST HTS current leads.