Thermal-Engineering Stucy on Early Detection of Quench and Hyper Stabilization Method of Superconducting Coil

超导线圈失超早期检测及超稳定方法的热工研究

基本信息

批准号：
03452126
负责人：
AIHARA Toshio
金额：
$ 4.22万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452126/
关键词：
Superconductor Thermal Stability Immersion Cooling Forced Cooling Heat Transfer 超伝導体

项目摘要

The aim of this research project is to clarify thermal mechanism of quench in forced-and immersion-cooled superconducting coils, and to establish theory of thermal stability of superconducting coil, and to propose methods for early detection of the quench. The outline of the results obtained in this 3-year research project is given below.1. Numerical analyzes of quench mechanism and thermal stability of forced-and immersion-cooled superconducting coils were carried out. Various influences of governing factors on them were clarified quantitatively and the basic concept of early prediction of quench was established.2. Since the quench phenomenon is extremely rapid transient and indeterminate, and it occurs in a very strong magnetic field, it is almost impossible to predict the time and place of its occurrence. hence we propose two novel detecting methods : one is a film thermal sensor, and another is a visualization technique.Practical applicability of the film thermal sensor was examine … More d in an experiment on rapid transient boiling heat transfer of a pulse-heated strip in liquid helium. The data obtained in the experiment are also necessary for the precise analysis of the thermal stability. The test piece was a 20-mum-thick stainless steel strip, both surface of which were coated with PVF film and a carbon-paste film. This strip structure was to simulate an insulated superconductor in practical use and the carbon-paste film performed the part of an electric resistance thermometer. The heat-transfer data were reduced from the experimental raw values by numerical calculation considering the heat capacity and transient temperature distribution of the coating layrs : the obtained results had satisfactory accuracy to apply the film sensor to the early detection of quench initiation.As for a visualization technique of quench and its rapid propagation was investigated using a pancake-type superconducting coil immesed in liquid helium. It was found that the visualization technique will be a promising tool of the early detectin of quench ; however, we need further research to make applicatin of this charming technique to practical superconducting coils. Less

该研究项目的目的是阐明强制和浸入冷却的超导线圈中淬灭的热机制，并建立超导线圈的热稳定性理论，并提出提出早期检测淬灭的方法。下面给出了该3年研究项目中获得的结果的概述1。对强制和浸入冷却的超导线圈的淬灭机制和热稳定性的数值分析。定量阐明了管理因素对它们的各种影响，并建立了早期预测的基本概念。2。由于淬灭现象是非常快速的瞬态和不确定的，并且发生在非常强的磁场中，因此几乎不可能预测其发生的时间和地点。因此，我们提出了两种新型检测方法：一种是膜热传感器，另一个是可视化技术。检查了膜热传感器的实践适用性……在有关液体氦气中脉搏加热条的快速短暂沸腾热传递的实验中，更多的d。在实验中获得的数据对于热稳定性的精确分析也是必需的。测试件是20张厚的不锈钢带，两层表面都涂有PVF膜和碳 - 帕斯特膜。这种带状结构是为了模拟实际使用中的绝缘超导体，并将碳 - 帕斯特膜用于电阻温度计的一部分。通过数值计算考虑，从实验原始值中降低了热转移数据的热容量和临时温度分布：获得的结果具有令人满意的精度，可以将膜传感器应用于Quench Initiative的早期检测。用于使用液体螺旋螺旋式的旋转技术可视化技术及其快速传播的速度超级构图。发现可视化技术将是早期检测淬蛋白的承诺工具。但是，我们需要进一步的研究来使这种迷人的技术在实用的超导线圈中应用。较少的