Mixed refrigerant recovering and supplementing method and device

Abstract

The invention relates to a mixed refrigerant recovering and supplementing method and a device, is suitable for being applied to a natural gas liquefaction flow adopting a mixed refrigerant liquefying process, and is used for recovering gas-phase mixed refrigerant in a refrigerant compression system in the parking of a natural gas liquefying device and supplementing the gas-phase mixed refrigerant to the refrigerant compression system in the driving of the device; a gas-phase refrigerant storage tank filled with modified active carbons is adopted to recover the gas-phase mixed refrigerant; residual mixed refrigerant absorbed by the modified active carbons in the supplementation of the refrigerant is regenerated by hot gas of the refrigerant compression system; and the regenerated gas is returned to the refrigerant compression system. The method and the device can prominently improve the recovery amount of the gas-phase mixed refrigerant, so that the equipment volume is reduced, and the recovery difficulties of the gas-phase mixed refrigerant are solved; and one part of the gas-phase refrigerant is duly recovered and supplemented to adjust the proportions and the flows of light components in the mixed refrigerant, so that the variable-working condition adaptability of the mixed refrigerant liquefaction flow can be improved.

Description

technical field [0001] The invention belongs to the field of low-temperature liquefaction of natural gas, and in particular relates to a method and device for recovering and replenishing mixed refrigerant. Background technique [0002] The natural gas liquefaction process adopted by the natural gas liquefaction plant has several different types, which can be divided into the following three types according to the refrigeration method: cascade liquefaction process, mixed refrigerant liquefaction process, and liquefaction process with expander. The cascade liquefaction process has the lowest energy consumption, but has many moving equipment and complicated operation; the liquefaction process with an expander has the disadvantages of high energy consumption and relatively complicated operation; the advantage of the mixed refrigerant liquefaction process is that it has low energy consumption and less moving equipment It is widely used in base-load liquefaction plants and peak-sh...

AI Technical Summary

Problems solved by technology

The cascade liquefaction process has the lowest energy consumption, but has many moving equipment and complicated operation; the liquefaction process with an expander has the disadvantages of high energy consumption and relatively complicated operation; the advantage of the mixed refrigerant liquefaction process is that it has low energy consumption and less moving equipment It is widely used in base load liquefaction unit and peak shaving liquefaction unit

However, the mixed refrigerant liquefaction process has problems such as difficult recovery of refrigerant light components and poor adaptability to variable working conditions.

Usually, when the device is shut down, the refrigerant components that cannot be recovered are emptied and sent to the torch, resulting in great waste. This invention proposes a new refrigerant recovery and replenishment method to solve the difficulties in the recovery of light components of refrigerants and variable working conditions. The problem of poor adaptability

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