| abstract |
ABSTRACT OF DISCLOSURE A method and system for delivering high pressure, subcooled liquid carbon dioxide. An insulated tank having a height greater than its internal diameter holds liquid CO2 to a depth of at least about 6 feet, and high pressure, subcooled liquid CO2 is delivered from a lower outlet of the tank. CO2 vapor is condensed in the upper region to maintain a desired high pressure, e.g., about 290-310 psig., at the top of the tank. By withdrawing liquid CO2 from an upper region in the tank, subcooling it by heat exchange and returning subcooled liquid CO2 to a lower region, a thermocline region is created at least 2 feet below the surface, and above which equilibrium high pressure liquid CO2 exists. Heat exchange is efficiently carried out during off hours using liquid carbon dioxide to chill the condensed refrigerant from an existing auxiliary mechanical refrigeration unit. |