Experimental Measurement of Thermal Conductivities in a Thin Heterogeneous Structure of Thermal Diodes

¹ Department of Energy and Power Engineering, Tsinghua University, 100084, Beijing, China
² Renewable Energy Resources Lab, Department of Mechanical and Aerospace Engineering, University of California, Irvine, 92697-3975, CA, United States

^* Corresponding author: zhewang@tsinghua.edu.cn

Abstract

Thermal diode has a wide application in the field of thermal management and thermal control. This article reports experimental results about measurement of the thermal conductivities of a novel thin layer (the thickness is about 0.3mm) for thermal diode applications. The layer consists printing paper, nylon mesh and liquid water, which are sealed between two pieces of aluminum, thus has a heterogeneity sublayers structure. It is shown that the thermal conductances are different in the two opposite through-plane directions. At 75 ˚C, the thermal conductivity is 0.457 W/mK in the conductive direction, more than 3 times larger than that in the opposite direction (0.133 W/mK). This phenomenon is due to the one-direction flow of working fluid. The thermal performance is dependent on the operating temperature and liquid water content in the structure.