Fluorescent paint for determination on the effective thermal conductivity of YBCO coated conductor
Fluorescent paint for determination on the effective thermal conductivity of YBCO coated conductor
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DOI：
10.1088/1361-6668/abc2a6
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发表时间：
2021-02
影响因子：
3.6
通讯作者：
Yingbo Li;Yanbin Ma;Cong Liu;Xingyi Zhang;H. Yong;Youhe Zhou
中科院分区：
文献类型：
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作者：
Yingbo Li;Yanbin Ma;Cong Liu;Xingyi Zhang;H. Yong;Youhe Zhou
近年来，YBa2Cu3O7−x涂层导体(YBCOCC)在电力电缆和高场强磁体等不同领域得到了广泛的应用。在YBCO CC的所有物理性能中，导热系数被认为是指导温度分布、热流密度和预测失超传播的最重要的参数之一。为了准确地预测这一性能，本研究引入了高速荧光热成像测温技术，以EuTFC为基础，实时监测商用YBCO CCS的热扩散。我们提出了一种新的成像方法，消除了背景强度和光照不均匀对定标结果的影响，同时具有良好的测量精度。并通过静态和动态标定实验对其荧光性能进行了评价。实验结果表明，EuTFC的光致发光具有良好的光稳定性和温度依赖性，与PT100的测量结果相比，其温度响应没有滞后现象。随后，给出了四种常用的热导率理论模型，并给出了相应的YBCO连铸机的计算曲线。最后，在理论模型的基础上进行了数值模拟，再现了非稳态导热过程。模拟结果表明，麦克斯韦等效模型预测的瞬时导热系数与实验结果吻合最好。
Recently, YBa2Cu3O7−x coated conductor (YBCO CC) has been developed intensively for different applications including power cables and high-filed magnets. Of all its physical properties, the thermal conductivity of the YBCO CC is considered as one of the most important parameters in guiding the temperature distribution, heat flux, and prediction of quench propagation. To accurately predict this property, a thermometry technique of high-speed fluorescent thermal imaging is introduced to monitor heat diffusion of commercial YBCO CCs in real time based on the Europium tris[3-(trifluoromethylhydroxymethylene)-(+)-camphorate] (EuTFC) in this study. We propose a new imaging process to eliminate the influences of background intensity and non-uniform illumination on the calibration results accompanying with good accuracy of measurement. And the fluorescence performances are evaluated by static and dynamic calibration experiments. The experimental results show that the photoluminescence of EuTFC has excellent photostability and temperature dependence, and there is no hysteresis in the temperature response when comparing with the PT100 measurements. Subsequently, four kinds of commonly used theoretical models of thermal conductivity and the corresponding calculation curves of the YBCO CC are presented. Finally, the numerical simulation based on the theoretical models has been conducted to reproduce the transient heat conduction process. The simulation results show that the transient heat conduction predicted by the Maxwell’s equivalent model show the best agreement compared with experimental results.