The study looked at how cold loading affects the structure of coal in coalbed methane reservoirs. By applying pressure and injecting liquid nitrogen into coal samples, researchers found that higher pressure leads to more damage in the coal structure. After three cycles of cold loading under high pressure, the coal sample broke. Without pressure, the coal sample is more likely to be damaged by the cold liquid nitrogen. Fractures in the coal extend along certain directions, which is important for improving gas permeability in coal seams.