Reconstruction of Intrinsic Thermal Parameters of Methane Hydrate and Thermal Contact Resistance by Freestanding 3ω Method**Supported by the National Natural Science Foundation of China under Grant No U1262112, and the Fundamental Research Funds for the Central Universities under Grant No 18CX06035A.

Abstract

It is essential to obtain thermophysical properties of methane hydrate precisely with a freestanding probe for modeling and predicting thermal transport in gas hydrates. A method with a freestanding 3ω probe is presented to reconstruct the intrinsic thermal conductivity, thermal diffusivity, and thermal contact resistance of methane hydrate. Isolated from the thermal contact resistance, the intrinsic thermal conductivity of methane hydrate decreases between 250 K and 280 K and is 41% larger than the effective value at 253 K. More importantly, when the thermal contact resistance is isolated, the temperature dependence of intrinsic thermal conductivity shows a converse trend with the generally accepted glass-like feature at high temperature. Otherwise, thermal contact resistances measured in the experiment between the freestanding 3ω probe and the methane hydrate sample are extraordinary large. The freestanding 3ω method in this work is expected to measure the thermal property of methane hydrate more accurately.