The invention discloses an energy
cascade comprehensive utilization method of LNG (
liquefied natural gas) cold energy. The energy
cascade comprehensive utilization method comprises the following steps that firstly, the LNG cold energy of a deep cold part is converted into
electric energy by
Rankine cycle power generation; then, the LNG cold energy of a middle cold part is recovered by a
cooling medium for supplying cold to a
cold storage warehouse, meanwhile, the gasifying pressure of a power generation working medium in the
Rankine cycle power
generation process is controlled, the cold energy released by the gasifying of the liquid power generation working medium is matched with the temperature of the required cold energy of the
cold storage warehouse, and the cold energy released by the gasifying of the liquid power generation working medium is used as a cold source for supplying cold to the
cold storage warehouse; and the LNG cold energy of a shallow cold part is recovered and used as a cold source for an air conditioner
system of a cold storage
plant, and is used for supplying cold to
product processing workshops of the cold storage, office buildings and storage warehouses. The energy
cascade comprehensive utilization method has the advantages that through the
system integration, the LNG is gradually used for power generation, cold supply of cold storage warehouses and cold supply of
plant air conditioners from
lower grade to upper grade according to the temperatures, the cascade utilization of the cold energy is realized, and the cold energy of the LNG is utilized highly efficiently in the low-temperature cold storages.