Propane pre-cooling double-mixing refrigerant serial-connection liquefaction system

Abstract

The invention discloses a propane pre-cooling double-mixing refrigerant serial-connection liquefaction system, which comprises a pre-cooling cold box a, a pre-cooling cold box b, a liquefaction cold box a, a liquefaction cold box b, a deep-cooling cold box a, a deep-cooling cold box b, a propane pre-cooling circulating mechanism, a mixed refrigerant liquefaction circulating mechanism and a mixed refrigeration deep-cooling circulating mechanism, wherein the propane pre-cooling circulating mechanism comprises a three-grade compression unit; the mixed refrigerant liquefaction circulating mechanism comprises a first-grade compression unit; and the mixed refrigeration deep-cooling circulating mechanism comprises a first-grade compression unit. The liquefaction system provided by the invention adopts the propane pre-cooling double-mixing refrigerant parallel-connection refrigeration mode, and liquefaction and undercooling circulation respectively adopt independent mixing refrigerant refrigeration circulation; the power distribution of three compressor units (one pre-cooling circulation compressor, one liquefaction circulation compressor and one undercooling circulation compressor) is effectively balanced; the limitation on that the processing capability of the whole liquefaction device is affected because one compressor has too large power can be broken through; and meanwhile the maneuverability of the device can be improved.

Description

technical field [0001] The invention relates to a propane precooling double mixed refrigerant series liquefaction system, in particular to a propane precooling double mixed refrigerant series liquefaction system applied to a base-load type natural gas liquefaction plant, belonging to the technical field of natural gas liquefaction. Background technique [0002] At present, most common natural gas liquefaction technologies in China are nitrogen expansion, cascade refrigeration or single-stage mixed refrigerant cycle refrigeration process, which can only be applied to small-scale LNG plants. Among the liquefaction technologies used in foreign base-load natural gas liquefaction plants, tank-type or shell-and-tube heat exchangers are often used for propane precooling, which has poor heat transfer performance and wastes equipment investment. The investment in equipment is high and the dependence on imported equipment is high. [0003] In the liquefaction technology of the base-l...

AI Technical Summary

Problems solved by technology

Among the liquefaction technologies used in foreign base-load natural gas liquefaction plants, tank-type or shell-and-tube heat exchangers are often used for propane precooling, which has poor heat transfer performance and wastes equipment investment. High equipment investment and high dependence on imported equipment

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