A kind of process method of full recovery of mixed refrigerant

Abstract

The invention relates to the oil and gas industry and the technical field of refrigerant recovery, in particular to a process method for full recovery of mixed refrigerants, which isolates cold and hot refrigerants into two systems and recovers them separately. The hot and low-pressure refrigerant is boosted to high pressure by a small compressor and stored in a high-pressure state; the hot and high-pressure refrigerant is recovered to the refrigerant recovery tank through a refrigerant pump, and the rest of the gas phase is depressurized and then recovered by a compressor; low temperature The refrigerant is recovered to the low-temperature refrigerant recovery tank through the system pressure supplement, and the temperature is controlled to stabilize. When the machine is restarted, it is directly replenished to the low-temperature side of the cold box to reduce the pre-cooling time and realize the complete recovery of the refrigerant.

Description

technical field [0001] The invention relates to the oil and gas industry and the technical field of refrigerant recovery, in particular to a process method for full recovery of mixed refrigerant. Background technique [0002] As a high-quality, efficient and clean fuel, natural gas is being increasingly widely developed and utilized in the fields of energy and transportation. The primary issue in the development and utilization of natural gas is its liquefaction and storage. In recent years, the liquefied natural gas industry has developed rapidly in China, and more and more liquefied natural gas devices have been built and put into operation. Most of the installations that have been built or are under construction use the mixed refrigerant refrigeration process. Mixed refrigerants generally consist of nitrogen, methane, ethylene or ethane, propane or propylene, butane and pentane. When the liquefied natural gas plant is in normal operation, only a small amount of repleni...

AI Technical Summary

Problems solved by technology

The main components of the mixed refrigerant are nitrogen, methane, ethylene, propane, butane and pentane, among which ethylene, propane, butane and pentane are petrochemical products with high prices, and a large amount of refrigerant will be released during the maintenance of the device. Cause serious waste of resources and increase operating costs

[0004] At present, some patents, such as the patent application "A Method and System for Recycling and Utilizing Mixed Refrigerants" with the publication number CN 103383182 A, although they have played a role in refrigerant recovery, due to the imperfect process, full recovery cannot be realized, and parking After starting up again, the refrigerant returned to the system is less than 60% of the original refrigerant, and due to the lack of cooling recovery, the refrigerant needs to be lowered to a low temperature again, and the restart process is slow, which seriously reduces the economical efficiency of the device

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