Offshore natural gas liquefaction system with mixed refrigerant integrated nitrogen expansion cycle

Abstract

The invention discloses an offshore natural gas liquefaction system with a mixed refrigerant integrated nitrogen expansion cycle, which includes a natural gas liquefaction pipeline and a natural gas liquefaction device. The natural gas liquefaction device includes a mixed refrigerant cycle system and a nitrogen expansion supercooling cycle system. The liquefaction and liquefaction part adopts mixed refrigerant liquefaction, and the cryogenic part adopts nitrogen expansion refrigeration process, which reduces the average heat transfer temperature difference in the pre-cooling and liquefaction cycle and improves the utilization rate of cold energy; the refrigerant selection of the mixed refrigerant cycle system Refrigerant mixtures of light hydrocarbons such as nitrogen, methane, and ethane are used, and the liquefaction efficiency is improved. Compared with the traditional nitrogen expansion liquefaction system, the liquefaction efficiency of the entire liquefaction system is greatly improved, and the single-line production capacity is also increased compared with the traditional SMR process. In addition, the liquefaction system design does not use propane refrigerant in the mixed refrigerant cycle system, reducing the safety risk of offshore natural gas liquefaction process units.

Description

technical field [0001] The invention relates to the technical field of petrochemicals, and more particularly, to an offshore natural gas liquefaction system with a mixed refrigerant integrated nitrogen expansion cycle. Background technique [0002] With the rapid increase in the demand for natural gas, the development of deep-sea natural gas resources has also received extensive attention. Floating Liquefied Natural Gas (FLNG) is a mobile offshore natural gas plant that integrates natural gas extraction, processing, liquefaction, storage, and export. The application of FLNG in deep-water seas will effectively avoid deep-water seas. The technical difficulties faced by pipeline laying also provide a cost-effective solution for the development of offshore marginal oil and gas fields. Natural gas liquefaction process is the core technology of FLNG. At present, there are relatively few FLNG actually put into commercial production in the world. Due to insufficient experience in ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems existing in the prior art, the object of the present invention is to provide an offshore natural gas liquefaction system with a mixed refrigerant integrated nitrogen expansion cycle, which is used to solve the problem of relatively low efficiency of traditional nitrogen expansion liquefaction, and the problem of propane refrigerant in the offshore platform security risks

Images