Combustion experiment and numerical simulation of methane hydrate sediment under different airflow environments

Abstract

Combustion optimization research on methane hydrate sediment will help advance the application of in-situ combustion technology, which is dealt within this paper. The combustion evolution of methane hydrate sediment under five airflow environments were observed experimentally, and numerical simulations were carried out to analyze the combustion characteristics of methane hydrate sediment under forced airflow. The results demonstrate that the flame of methane hydrate sediment under different airflow environments show staged evolution characteristics. High-velocity longitudinal airflow has both the physical effect of the momentum transfer and the chemical effect of oxygen transportation and combustion support, which have the greatest application potential. Longitudinal ducted airflow increases reaction intensity in the center of the combustion zone, but also physically dilutes and cools the flame. The applicable flow velocity range of the crossflow is relatively narrow. Too small airflow wind velocity will weaken the transport of oxygen, and too large airflow wind velocity will cause the flame high temperature zone to shrink and the flame to tilt excessively. Convective airflow may result in a significant reduction in combustion stability and continuity and it is not appropriate for combustion optimization of hydrate sediment.