Carbon dioxide compression energy storage system and method

The invention relates to the technical field of compression energy storage, in particular to a carbon dioxide compression energy storage system and method. Carbon dioxide at the shaft end is sealed by sealing the gas tank, introducing sealing gas and the shaft sealing fan, carbon dioxide gas is prevented from leaking to the outside, and high-temperature gas can also be prevented from being exposed to a plant to cause personal injury; meanwhile, a separator is added, the mixed media (carbon dioxide and sealing gas) are separated, and the separated carbon dioxide and sealing gas respectively enter the low-pressure gas storage unit and the sealing gas tank again and are repeatedly used. According to the system, carbon dioxide can be prevented from being exposed, meanwhile, the system efficiency and the energy density are improved, and the economical efficiency is further improved. Compared with an existing carbon dioxide system which prevents gas in through-flow from leaking to the outside only through sealing g