Study of neon heat flux in thermosyphon cooling system for high-temperature superconducting machinery
Study of neon heat flux in thermosyphon cooling system for high-temperature superconducting machinery
复制标题
高温超导机械热虹吸冷却系统氖热通量研究
DOI：
10.1016/j.ijthermalsci.2019.04.030
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发表时间：
2019
影响因子：
4.5
通讯作者：
Oryu T.
中科院分区：
文献类型：
--
作者：
Yamaguchi K.;Miki M.;Shaanika E.;Izumi M.;Murase Y.;Oryu T.
高温超导体在旋转机械中的应用是船舶工业实现高功率密度、高效率电力推进系统的迫切需求。为使船用推进电机中的高温超导场极磁体达到最佳性能，必须将其工作温度控制在40 K以下，并需要一个简单可靠的冷却系统。热虹吸管（TS）是非常合适的，因为其操作原理在于使用自然对流而无需机械循环泵的干预。系统组成简单、重量轻。TS得益于潜热带来的高传热系数。TS的可用温度取决于制冷剂的饱和温度，该饱和温度为低温机器应用提供足够的可控冷却。使用氖的TS系统使我们能够提供28-40 K范围的冷却温度。为确定高温超导电机的最佳气液两相运行方式，设计并搭建了20 MW电机高温超导冷却系统的缩比模型。这使我们能够可视化转子蒸发器部分内部的任何现象和瞬态变化。研究了不同氖量下热负荷下的传热能力。然后计算氖热通量以确定有效冷却的传热面积。沸腾曲线导致具有最佳传热面积的精炼蒸发器设计。在冷凝器和蒸发器之间引入同轴管，实现了在船舶运行所需的倾斜条件下，可能的持续不间断的液-气循环。研究结果为下一步高温超导船舶推进电机和超导电机的设计提供了参考。
High-temperature superconductors (HTS) applied to rotating machine draw much interest in the shipbuilding industry as the urge to get high-power density and efficient electric propulsion systems. To achieve an optimal performance of HTS field pole magnets in ship propulsion motors, it is crucial to regulate the operating temperature under 40 K and a simple and reliable cooling system is necessary. A thermosyphon (TS) is highly suitable since its operation principle consists in using natural convection without the intervention of mechanical circulation pump. The system composition is simple and light-weight. The TS benefits from a high heat transfer coefficient thanks to latent heat. The available temperature for TS depends on the saturation temperature of the refrigerant, which provides adequate controllable cooling for cryogenic machine application. A TS system using neon enables us to supply cooling temperatures of 28–40 K range. To determine the optimal gas-liquid state operation for HTS motors, a scaled model of a 20 MW motor TS cooling system was designed and constructed. This enabled us to visualize any phenomena and transient state change inside the evaporator part of the rotor. We studied heat transfer capacity under heat load for different neon quantities. Neon heat flux was then calculated to determine the heat transfer area for effective cooling. The boiling curve leads to the refined evaporator design with optimal heat transfer area. Introducing coaxial tubing between condenser and evaporator, possible sustainable liquid-gas circulation has been achieved without interruption under inclined condition required for ship operation. The present results contribute to the next stage HTS ship propulsion motor and superconducting machine design.