High-rectification near-field thermal diode using phase change periodic nanostructure
High-rectification near-field thermal diode using phase change periodic nanostructure
复制标题
DOI：
10.1063/1.4963317
复制
发表时间：
2016-09-19
影响因子：
4
通讯作者：
Zheng, Yi
中科院分区：
文献类型：
--
作者：
Ghanekar, Alok;Ji, Jun;Zheng, Yi
我们从理论上论证了近场热整流装置的工作原理，该装置利用相变材料来实现辐射换热的非对称性。我们利用了VO2在341K附近金属-绝缘体转变引起的介电性质随温度变化的特性，类似于电二极管，单向的换热系数很高，而当温度梯度的极性相反时，换热系数很小。结果表明，采用一维矩形和三角形VO2面栅可以大大提高热整流效率。随着周期光栅的引入，由于表面波在负极性界面上的隧穿减少，近场整流比得到显著提高。我们的计算表明，在最小温差为20K的情况下，精馏比可达16，在现有文献中，对于类似的操作温度和分离，它是最大的。由AIP出版公司出版。
We theoretically demonstrate workings of a near-field thermal rectification device that uses a phase change material to achieve asymmetry in radiative heat transfer. We exploit the temperature dependent dielectric properties of VO2 due to metal-insulator transition near 341 K. Analogous to an electrical diode, heat transfer coefficient is high in one direction while it is considerably small when the polarity of temperature gradient is reversed. We show that thermal rectification can be greatly enhanced by using 1-D rectangular and triangular VO2 surface gratings. With the introduction of periodic grating, rectification ratio is dramatically enhanced in the near-field due to reduced tunneling of surface waves across the interfaces for negative polarity. Our calculations predict that for minimal temperature difference of 20 K, the rectification ratio as high as 16 can be obtained, and it is maximum in existing literature for comparable operating temperatures and separation. Published by AIP Publishing.