Power plant using CO.sub.2 as a working fluid

A method for storing energy and then using such stored energy plus heat to generate electrical power, which method comprises the following steps

• creating a reservoir of carbon dioxide at about the triple point thereof, which reservoir contains a substantial percentage of solid carbon dioxide,
• withdrawing a stream of liquid carbon dioxide from said reservoir and very substantially increasing the pressure of said stream of withdrawn liquid,
• heating said higher pressure carbon dioxide,
• expanding said heated carbon dioxide to dry vapor or to vapor containing some entrained liquid to create rotary power,
• using said rotary power to generate electrical power, and
• returning the lower pressure stream to said reservoir where carbon dioxide vapor is condensed by melting solid carbon dioxide therein.

Apparatus for utilizing carbon dioxide slush in combination with the generation of power, which apparatus comprises:

• vessel means including a main vessel for holding carbon dioxide slush to an internal depth of at least about 15 feet,
• refrigeration means associated with said vessel means for creating a reservoir of carbon dioxide slush at the triple point,
• means for withdrawing liquid carbon dioxide from said vessel means, increasing the pressure of said withdrawn carbon dioxide, heating said pressurized carbon dioxide and expanding said heated carbon dioxide in a manner to perform useful work used in the generation of power and to create carbon dioxide vapor,
• said vessel means also including an auxiliary vessel,
• means for transferring carbon dioxide slush from said main vessel to said auxiliary vessel,
• means for returning said carbon dioxide vapor to said auxiliary vessel where it is condensed to liquid by melting solid carbon dioxide, and
• means for transferring liquid carbon dioxide from said auxiliary vessel to said main vessel.

A method for utilizing carbon dioxide slush in combination with the generation of electric power, which method comprises:

• establishing a reservoir zone containing carbon dioxide slush at the triple point to a depth of at least about 15 feet,
• withdrawing liquid carbon dioxide from said reservoir zone, increasing the pressure of said withdrawn carbon dioxide, heating said pressurized carbon dioxide and expanding said heated carbon dioxide to create carbon dioxide vapor in a manner to perform useful work in connection with the ultimate generation of electric power,
• transferring a portion of said carbon dioxide slush from a main section of said reservoir zone to a separate auxiliary section thereof,
• returning said carbon dioxide vapor to said auxiliary reservoir section in a manner so that it is condensed to liquid by melting solid carbon dioxide, and
• transferring liquid carbon dioxide from said auxiliary reservoir section to said main reservoir section.