Mixed refrigerant recovery and reinjection process and device

Abstract

The invention relates to a mixed refrigerant recovery and reinjection process in a natural gas liquefying device. The process includes the steps of adding a special channel to a fin type heat exchanger, wherein the special channel is used for recovering mixed refrigerant in a refrigerant circulating system; arranging a special device and a special pipeline to reinject the mixed refrigerant into a refrigerant system. The mixed refrigerant recovery and reinjection process and device are suitable for recovering and reinjecting the refrigerant when the refrigerant liquefying device is stopped and started again and recovering and reinjecting the refrigerant when the refrigerant ratio is adjusted, and the problems that refrigerant recovery is difficult, and the liquefying device is poor in variable-working-condition adaptive capacity are solved.

Description

technical field [0001] The invention relates to a process and device for recovering and reinjecting mixed refrigerant, in particular to a process and device for recovering and reinjecting mixed refrigerant in a natural gas liquefaction device when the mixed refrigerant liquefaction device is shut down or when the refrigerant ratio is adjusted. 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 liquefac...

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 mixed refrigerant recovery process to solve the problems of difficulty in refrigerant recovery and poor adaptability to changing working conditions of the liquefaction device question

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