LNG cold power generation using mixed working fluid
AssigneeSK Gas Co., Ltd.
InventorsJungho Cho, Ung Gi Hong, Mi Young Lee
Life of this patent
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Abstract
LNG cold power generator includes: a working fluid including carbon dioxide and ethane; a pump; an evaporator; a turbine; and a condenser. A molar ratio of the carbon dioxide and the ethane is 85˜95:15:0.5. The working fluid is used in a closed Rankine cycle. A supply pressure of supplied LNG is adjusted to a pressure at which it becomes a saturated liquid. A temperature at an outlet of the condenser is adjusted to a saturated vapor temperature of LNG. A pressure at an outlet of the pump is adjusted to a critical pressure of a mixed working fluid. The cycle includes two turbines and a heater provided therebetween. The heater heats the working fluid to prevent condensation thereof.
Claims2
An LNG cold power generation system comprising:
- a working fluid comprising carbon dioxide and ethane at a molar ratio of carbon dioxide:ethane of 85-95:15-0.5;
- a pump;
- an evaporator;
- two turbines and a heater provided therebetween;
- and
- a condenser,
- wherein:
- the LNG cold power generation system is configured to use the working fluid in a closed Rankine cycle,
- a supply pressure of supplied LNG is a pressure at which LNG becomes a saturated liquid,
- a temperature at an outlet of the condenser is a saturated vapor temperature of LNG,
- a pressure at an outlet of the pump is a critical pressure of the working fluid,
- the heater heats the working fluid in an amount sufficient to prevent condensation thereof,
- either or both of the evaporator and the heater utilize waste heat in a process, and
- a temperature at an outlet of the condenser is within 3° C. of the LNG's temperature when fully evaporated.
A method of generating LNG cold power comprising:
- supplying a working fluid comprising carbon dioxide and ethane at a molar ratio of carbon dioxide:
- ethane of 85-95:15-0.5 to an LNG cold power generation system that comprises a pump, an evaporator, two turbines and a heater provided therebetween, and a condenser,
- using the working fluid in a closed Rankine cycle,
- supplying LNG at a pressure at which LNG becomes a saturated liquid,
- maintaining a temperature at an outlet of the condenser at a saturated vapor temperature of LNG,
- maintaining a pressure at an outlet of the pump at a critical pressure of the working fluid,
- using the heater to heat the working fluid in an amount sufficient to prevent condensation thereof,
- utilizing waste heat in either or both of the evaporator and the heater, and
- maintaining a temperature at an outlet of the condenser within 3° C. of the LNG's temperature when fully evaporated.
Dependencies are inferred from the claim text.