Heat transfer with kinetic phase transition in geomaterials

Different from normal and high temperature, pore water will freeze at low temperature, and thus the heat transfer process in rocks is more complex but less investigated. In this paper, we establish a model to describe the process of heat transfer in rocks with phase transition. The kinetic feature of phase transition is considered here, in comparison with the conventional equilibrium model that assumes the phase transition process is instantaneous. The established model is calibrated and validated by heating tests of water-saturated sandstone and coal samples. In particular, our model can reproduce the observed temperature plateau located above the melting point (0 degrees C), which however cannot be explained by the equilibrium model. When the kinetic rate coefficient is high enough, the temperature plateau approaches the melting point, and our model reduces to the equilibrium model. Further parameter analysis is also conducted on the influencing factors such as kinetic rate coefficient, specific heat, convection coefficient, and environment temperature. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This paper investigates the heat transfer process in rocks with phase transition, establishing a model that considers the kinetic feature of phase transition and conducting calibration and validation. It was found that when the kinetic rate coefficient is high enough, the temperature plateau approaches the melting point, and the model reduces to the equilibrium model.