Molecular dynamics simulation investigation of the microwave heating supercritical water

摘要

Nonequilibrium NVE molecular dynamics (MD) simulations were performed to investigate the heating process of supercritical water (SCW) by the microwaves (the field intensities are from 3 x 10(5)V/m to 3 x 10(9)V/m with the frequencies of 915 MHz and 2.45 GHz, respectively). The energy distribution, microscopic molecular structure, diffusivity and hydrogen bond dynamics were analyzed. Microwaves field dependence on the rotational and translational coupling mechanisms of water molecules have been detected. The microwave energy has been converted to the kinetic and intermolecular energies of water. There are about 40% absorbed microwave energy is stored as the intermolecular energy, and the proportion decline at higher field intensity. The diffusion of super-critical water is non-linearly fluctuation due to the coupling of rotation and translation motions. And this work may provide a theoretical basis to improve the efficiency of industrial application with microwave and SCW. (C) 2019 Elsevier B.V. All rights reserved.