Method for freezing and purifying carbon dioxide gas in air in closed space by utilizing liquid oxygen cooling capacity

The invention discloses a method for freezing and purifying carbon dioxide gas in the air in a closed space by utilizing liquid oxygen cooling capacity. The method is characterized in that a scheme for freezing and removing carbon dioxide gas generated by respiratory metabolism of a human body by utilizing the liquid oxygen cooling capacity through a low-temperature separation method is provided for the first time, a liquid oxygen cooling capacity recycling method and a low-temperature freezing carbon dioxide separation method are combined, liquid oxygen is utilized as a cold source, energy generated by liquid oxygen cooling capacity recovery is fully utilized, carbon dioxide in the air is frozen (desublimated) and separated out under normal pressure by means of the substance characteristic that the carbon dioxide phase change (desublimation) critical point is different from other gas components, and a new technical way for removing the carbon dioxide in the closed space is achieved. 本发明公开了一种利用液氧冷量来冻结净化密闭空间的空